The current and ideal state of anatomic pathology patient safety.

PubMed

Raab, Stephen Spencer

2014-01-01

An anatomic pathology diagnostic error may be secondary to a number of active and latent technical and/or cognitive components, which may occur anywhere along the total testing process in clinical and/or laboratory domains. For the pathologist interpretive steps of diagnosis, we examine Kahneman's framework of slow and fast thinking to explain different causes of error in precision (agreement) and in accuracy (truth). The pathologist cognitive diagnostic process involves image pattern recognition and a slow thinking error may be caused by the application of different rationally-constructed mental maps of image criteria/patterns by different pathologists. This type of error is partly related to a system failure in standardizing the application of these maps. A fast thinking error involves the flawed leap from image pattern to incorrect diagnosis. In the ideal state, anatomic pathology systems would target these cognitive error causes as well as the technical latent factors that lead to error.

The interpretation and management of abnormal liver function tests.

PubMed

Simpson, M A; Freshwater, D A

2015-01-01

Liver function tests (LFTs) are frequently requested as part of routine health assessments on serving members of the Royal Navy (RN). In common with many investigations there are a number of abnormal results in healthy individuals (0.5 - 9% depending on test and study population). There are established patterns of LFT derangement such as cholestatic derangement, hepatocellular derangement, and failure of synthetic function. There can be indicators to the cause of the derangement by assessing the ratios of elevated assays in relation to one another. This article aims to address the definition, potential causes and further investigation of common patterns of LFT derangement found in primary care in the RN.

Interprofessional communication failures in acute care chains: How can we identify the causes?

PubMed

van Leijen-Zeelenberg, Janneke E; van Raak, Arno J A; Duimel-Peeters, Inge G P; Kroese, Mariëlle E A L; Brink, Peter R G; Vrijhoef, Hubertus J M

2015-01-01

Although communication failures between professionals in acute care delivery occur, explanations for these failures remain unclear. We aim to gain a deeper understanding of interprofessional communication failures by assessing two different explanations for them. A multiple case study containing six cases (i.e. acute care chains) was carried out in which semi-structured interviews, physical artifacts and archival records were used for data collection. Data were entered into matrices and the pattern-matching technique was used to examine the two complementary propositions. Based on the level of standardization and integration present in the acute care chains, the six acute care chains could be divided into two categories of care processes, with the care chains equally distributed among the categories. Failures in communication occurred in both groups. Communication routines were embedded within organizations and descriptions of communication routines in the entire acute care chain could not be found. Based on the results, failures in communication could not exclusively be explained by literature on process typology. Literature on organizational routines was useful to explain the occurrence of communication failures in the acute care chains. Organizational routines can be seen as repetitive action patterns and play an important role in organizations, as most processes are carried out by means of routines. The results of this study imply that it is useful to further explore the role of organizational routines on interprofessional communication in acute care chains to develop a solution for failures in handover practices.

Factors influencing development of cracking-sliding failures of loess across the eastern Huangtu Plateau of China

NASA Astrophysics Data System (ADS)

Li, Yanrong; Mao, Jiarui; Xiang, Xiqiong; Mo, Ping

2018-04-01

Loess is a porous, weakly cemented, and unsaturated Quaternary sediment deposited by the wind in arid and semiarid regions. Loess is widely and thickly distributed in China, making the Huangtu Plateau the largest bulk accumulation of loess on Earth. However, the fragile geoenvironment in the loess areas of China causes frequent and various geohazards, such as cracking-sliding failure (beng-hua in Chinese), which is a typical geohazard that causes the largest number of casualties each year. This study investigates the main influencing factors and development patterns of cracking-sliding failure of loess to help prevent its occurrence and reduce losses effectively. The following conclusions are derived from this study: (1) cracking-sliding failures mostly take place in rectilinear slopes, convex slopes, slopes with gradients greater than 60°, slopes with heights of 5 to 40 m, and slopes mostly exposed to sunlight with aspects of 180 to 270°; (2) cracking-sliding failures occur mostly from 10 pm to 4 am and mainly in the rainy season (July to September) and in the freeze-thaw season (March to April); and (3) highly intense human activities in the region correspond to a high possibility of cracking-sliding failures.

Disparities in Patterns of Health Care Travel Among Inpatients Diagnosed With Congestive Heart Failure, Florida, 2011.

PubMed

Jia, Peng; Xierali, Imam M

2015-09-17

Congestive heart failure (CHF) is a major public health problem in the United States and is a leading cause of hospitalization in the elderly population. Understanding the health care travel patterns of CHF patients and their underlying cause is important to balance the supply and demand for local hospital resources. This article explores the nonclinical factors that prompt CHF patients to seek distant instead of local hospitalization. Local hospitalization was defined as inpatients staying within hospital service areas, and distant hospitalization was defined as inpatients traveling outside hospital service areas, based on individual hospital discharge data in 2011 generated by a Dartmouth-Swiss hybrid approach. Multiple logistic and linear regression models were used to compare the travel patterns of different groups of inpatients in Florida. Black patients, no-charge patients, patients living in large metropolitan areas, and patients with a low socioeconomic status were more likely to seek local hospitalization than were white patients, those who were privately insured, those who lived in rural areas, and those with a high socioeconomic status, respectively. Findings indicate that different populations diagnosed with CHF had different travel patterns for hospitalization. Changes or disruptions in local hospital supply could differentially affect different groups in a population. Policy makers could target efforts to CHF patients who are less likely to travel to seek treatment.

Disparities in Patterns of Health Care Travel Among Inpatients Diagnosed With Congestive Heart Failure, Florida, 2011

PubMed Central

Xierali, Imam M.

2015-01-01

Introduction Congestive heart failure (CHF) is a major public health problem in the United States and is a leading cause of hospitalization in the elderly population. Understanding the health care travel patterns of CHF patients and their underlying cause is important to balance the supply and demand for local hospital resources. This article explores the nonclinical factors that prompt CHF patients to seek distant instead of local hospitalization. Methods Local hospitalization was defined as inpatients staying within hospital service areas, and distant hospitalization was defined as inpatients traveling outside hospital service areas, based on individual hospital discharge data in 2011 generated by a Dartmouth–Swiss hybrid approach. Multiple logistic and linear regression models were used to compare the travel patterns of different groups of inpatients in Florida. Results Black patients, no-charge patients, patients living in large metropolitan areas, and patients with a low socioeconomic status were more likely to seek local hospitalization than were white patients, those who were privately insured, those who lived in rural areas, and those with a high socioeconomic status, respectively. Conclusion Findings indicate that different populations diagnosed with CHF had different travel patterns for hospitalization. Changes or disruptions in local hospital supply could differentially affect different groups in a population. Policy makers could target efforts to CHF patients who are less likely to travel to seek treatment. PMID:26378896

Causes of unusual distribution of coseismic landslides triggered by the Mw 6.1 2014 Ludian, Yunnan, China earthquake

NASA Astrophysics Data System (ADS)

Chen, Xiao-li; Liu, Chun-guo; Wang, Ming-ming; Zhou, Qing

2018-06-01

The Mw 6.1 2014 Ludian, Yunnan, China earthquake triggered numerous coseismic landslides that do not appear to be associated with any previously known seismogenic fault. Traditional models of triggering for seismically generated landslides do not provide a reasonable explanation for the landslide pattern observed here. Here the Newmark method is applied to a grid to calculate the minimum accelerations required for slope failures throughout the affected region. The results demonstrate that for much of the study area, the distribution of failure prone slopes is similar to the actual pattern of coseismic landslides, however there are some areas where the model predicts considerably fewer failures than occurred. We suggest that this is a result of the complex source faults that generated the Ludian earthquake, which produced a half-conjugate rupture on nearly EW- and NNW trending faults at depth. The rupture directed much of its seismic moment southeast of the epicenter, increasing ground shaking and the number of resulting landslides.

The hot (invisible?) hand: can time sequence patterns of success/failure in sports be modeled as repeated random independent trials?

PubMed

Yaari, Gur; Eisenmann, Shmuel

2011-01-01

The long lasting debate initiated by Gilovich, Vallone and Tversky in [Formula: see text] is revisited: does a "hot hand" phenomenon exist in sports? Hereby we come back to one of the cases analyzed by the original study, but with a much larger data set: all free throws taken during five regular seasons ([Formula: see text]) of the National Basketball Association (NBA). Evidence supporting the existence of the "hot hand" phenomenon is provided. However, while statistical traces of this phenomenon are observed in the data, an open question still remains: are these non random patterns a result of "success breeds success" and "failure breeds failure" mechanisms or simply "better" and "worse" periods? Although free throws data is not adequate to answer this question in a definite way, we speculate based on it, that the latter is the dominant cause behind the appearance of the "hot hand" phenomenon in the data.

SBDS Protein Expression Patterns in the Bone Marrow

PubMed Central

Wong, Trisha E.; Calicchio, Monica L.; Fleming, Mark D.; Shimamura, Akiko; Harris, Marian H.

2010-01-01

Shwachman Diamond Syndrome (SDS) is an inherited bone marrow failure syndrome caused by biallelic SBDS gene mutations. Here we examined SBDS protein levels in human bone marrow. SBDS protein expression was high in neutrophil progenitors, megakaryocytes, plasma cells and osteoblasts. In contrast, SBDS protein levels were low in all hematopoietic cell lineages from patients harboring the common SBDS mutations. We conclude that SBDS protein levels vary widely between specific marrow lineages. Uniformly low SBDS protein expression levels distinguish the majority of SDS patients from controls or other marrow failure syndromes. PMID:20658628

The influence of microstructure on the probability of early failure in aluminum-based interconnects

NASA Astrophysics Data System (ADS)

Dwyer, V. M.

2004-09-01

For electromigration in short aluminum interconnects terminated by tungsten vias, the well known "short-line" effect applies. In a similar manner, for longer lines, early failure is determined by a critical value Lcrit for the length of polygranular clusters. Any cluster shorter than Lcrit is "immortal" on the time scale of early failure where the figure of merit is not the standard t50 value (the time to 50% failures), but rather the total probability of early failure, Pcf. Pcf is a complex function of current density, linewidth, line length, and material properties (the median grain size d50 and grain size shape factor σd). It is calculated here using a model based around the theory of runs, which has proved itself to be a useful tool for assessing the probability of extreme events. Our analysis shows that Pcf is strongly dependent on σd, and a change in σd from 0.27 to 0.5 can cause an order of magnitude increase in Pcf under typical test conditions. This has implications for the web-based two-dimensional grain-growth simulator MIT/EmSim, which generates grain patterns with σd=0.27, while typical as-patterned structures are better represented by a σd in the range 0.4 - 0.6. The simulator will consequently overestimate interconnect reliability due to this particular electromigration failure mode.

Metabolomic does not predict response to cardiac resynchronization therapy in patients with heart failure.

PubMed

Padeletti, Luigi; Modesti, Pietro A; Cartei, Stella; Checchi, Luca; Ricciardi, Giuseppe; Pieragnolia, Paolo; Sacchi, Stefania; Padeletti, Margherita; Alterini, Brunetto; Pantaleo, Pietro; Hu, Xiaoyu; Tenori, Leonardo; Luchinat, Claudio

2014-04-01

Metabolomic, a systematic study of metabolites, may be a useful tool in understanding the pathological processes that underlie the occurrence and progression of a disease. We hypothesized that metabolomic would be helpful in assessing a specific pattern in heart failure patients, also according to the underlining causes and in defining, prior to device implantation, the responder and nonresponder patient to cardiac resynchronization therapy (CRT). In this prospective study, blood and urine samples were collected from 32 heart failure patients who underwent CRT. Clinical, electrocardiography and echocardiographic evaluation was performed in each patient before CRT and after 6 months of follow-up. Thirty-nine age and sex-matched healthy individuals were chosen as control group. For each sample, 1H-NMR spectra, Nuclear Overhauser Enhancement Spectroscopy, Carr-Purcell-Meiboom-Gill and diffusion edited spectra were measured. A different metabolomic fingerprint was demonstrated in heart failure patients compared to healthy controls with high accuracy level. Metabolomics fingerprint was similar between patients with ischemic and nonischemic dilated cardiomyopathy. At 6-month follow-up, metabolomic fingerprint was different from baseline. At follow-up, heart failure patients’ metabolomic fingerprint remained significantly different from that of healthy controls, and accuracy of cause discrimination remained low. Responders and nonresponders had a similar metabolic fingerprint at baseline and after 6 months of CRT. It is possible to identify a metabolomic fingerprint characterizing heart failure patients candidate to CRT, it is independent of the different causes of the disease and it is not predictive of the response to CRT.

What Counts as Successful School Subject Literacy: Differing Views from Students, Teachers, and Parents

ERIC Educational Resources Information Center

Bleicher, Robert E.

2014-01-01

Research into literacy and school subject performance focuses overwhelmingly on identifying and addressing risk factors associated with underachievement. Strenuous efforts are devoted to diagnosing the causes of literacy failure that are patterned by ethnicity, social class, and gender. This study explores the possibility that equal, or even…

Analysis of underlying and multiple-cause mortality data: the life table methods.

PubMed

Moussa, M A

1987-02-01

The stochastic compartment model concepts are employed to analyse and construct complete and abbreviated total mortality life tables, multiple-decrement life tables for a disease, under the underlying and pattern-of-failure definitions of mortality risk, cause-elimination life tables, cause-elimination effects on saved population through the gain in life expectancy as a consequence of eliminating the mortality risk, cause-delay life tables designed to translate the clinically observed increase in survival time as the population gain in life expectancy that would occur if a treatment protocol was made available to the general population and life tables for disease dependency in multiple-cause data.

Frequency-Magnitude relationships for Underwater Landslides of the Mediterranean Sea

NASA Astrophysics Data System (ADS)

Urgeles, R.; Gràcia, E.; Lo Iacono, C.; Sànchez-Serra, C.; Løvholt, F.

2017-12-01

An updated version of the submarine landslide database of the Mediterranean Sea contains 955 MTDs and 2608 failure scars showing that submarine landslides are ubiquitous features along Mediterranean continental margins. Their distribution reveals that major deltaic wedges display the larger submarine landslides, while seismically active margins are characterized by relatively small failures. In all regions, landslide size distributions display power law scaling for landslides > 1 km3. We find consistent differences on the exponent of the power law depending on the geodynamic setting. Active margins present steep slopes of the frequency-magnitude relationship whereas passive margins tend to display gentler slopes. This pattern likely responds to the common view that tectonically active margins have numerous but small failures, while passive margins have larger but fewer failures. Available age information suggests that failures exceeding 1000 km3 are infrequent and may recur every 40 kyr. Smaller failures that can still cause significant damage might be relatively frequent, with failures > 1 km3 likely recurring every 40 years. The database highlights that our knowledge of submarine landslide activity with time is limited to a few tens of thousand years. Available data suggest that submarine landslides may preferentially occur during lowstand periods, but no firm conclusion can be made on this respect, as only 149 landslides (out of 955 included in the database) have relatively accurate age determinations. The timing and regional changes in the frequency-magnitude distribution suggest that sedimentation patterns and pore pressure development have had a major role in triggering slope failures and control the sediment flux from mass wasting to the deep basin.

Comparison of tensile strength among simple interrupted, cruciate, intradermal, and subdermal suture patterns for incision closure in ex vivo canine skin specimens.

PubMed

Zellner, Eric M; Hedlund, Cheryl S; Kraus, Karl H; Burton, Andrew F; Kieves, Nina R

2016-06-15

OBJECTIVE To compare suture placement time, tension at skin separation and suture line failure, and mode of failure among 4 suture patterns. DESIGN Randomized trial. SAMPLE 60 skin specimens from the pelvic limbs of 30 purpose-bred Beagles. PROCEDURES Skin specimens were harvested within 2 hours after euthanasia and tested within 6 hours after harvest. An 8-cm incision was made in each specimen and sutured with 1 of 4 randomly assigned suture patterns (simple interrupted, cruciate, intradermal, or subdermal). Suture placement time and percentage of skin apposition were evaluated. Specimens were mounted in a calibrated material testing machine and distracted until suture line failure. Tensile strength at skin-edge separation and suture-line failure and mode of failure were compared among the 4 patterns. RESULTS Mean suture placement time for the cruciate pattern was significantly less than that for other patterns. Percentage of skin apposition did not differ among the 4 patterns. Mean tensile strength at skin-edge separation and suture-line failure for the simple interrupted and cruciate patterns were significantly higher than those for the intradermal and subdermal patterns. Mean tensile strength at skin-edge separation and suture-line failure did not differ significantly between the intradermal and subdermal patterns or the simple interrupted and cruciate patterns. The primary mode of failure for the simple interrupted pattern was suture breakage, whereas that for the cruciate, intradermal, and subdermal patterns was tissue failure. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested external skin sutures may be preferred for closure of incisions under tension to reduce risk of dehiscence.

Concomitant Wolff-Parkinson-White and Atrioventricular Nodal Reentrant Tachycardia: Which Pathway to Ablate?

PubMed

Sarsam, Sinan; Sidiqi, Ibrahim; Shah, Dipak; Zughaib, Marcel

2015-12-11

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common form of supraventricular tachycardia. In contrast, Wolff-Parkinson-White (WPW) pattern consists of an accessory pathway, which may result in the development of ventricular arrhythmias. Frequent tachycardia caused by AVNRT and accessory pathways may play a role in left ventricular systolic dysfunction. A 54-year-old man presented with palpitations and acute decompensated congestive heart failure. His baseline EKG showed Wolff-Parkinson-White (WPW) pattern. While hospitalized, he had an episode of atrioventricular nodal reentrant tachycardia (AVNRT). He underwent radiofrequency catheter ablation for AVNRT, and his accessory pathway was also ablated even though its conduction was found to be weak. He was clinically doing well on follow-up visit, with resolution of his heart failure symptoms and normalization of left ventricular function on echocardiography. This case raises the question whether the accessory pathway plays a role in the development of systolic dysfunction, and if there is any role for ablation in patients with asymptomatic WPW pattern.

Causes and Temporal Patterns of 30-Day Readmission Among Older Adults Hospitalized With Heart Failure With Preserved or Reduced Ejection Fraction.

PubMed

Goyal, Parag; Loop, Matthew; Chen, Ligong; Brown, Todd M; Durant, Raegan W; Safford, Monika M; Levitan, Emily B

2018-04-23

It is unknown whether causes and temporal patterns of 30-day readmission vary between heart failure (HF) with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF). We sought to address this question by examining a 5% national sample of Medicare beneficiaries. We included individuals who experienced a hospitalization for HFpEF or HFrEF between 2007 and 2013. We identified causes of 30-day readmission based on primary discharge diagnosis and further classified causes of readmission as HF-related, non-HF cardiovascular-related, and non-cardiovascular-related. We calculated the cumulative incidence of these classifications for HFpEF and HFrEF in a competing risks model and calculated subdistribution hazard ratios of these classifications by comparing those with HFpEF and those with HFrEF. Among 60 640 Medicare beneficiaries, we identified 13 785 unique older adults hospitalized with HFpEF and 15 205 who were hospitalized with HFrEF. Noncardiovascular diagnoses represented the most common causes of 30-day readmission (HFpEF: 59%; HFrEF: 47%), a pattern that was observed for each week of the 30-day study period for both HFpEF and HFrEF participants. In comparing readmission diagnoses in an adjusted model, non-cardiovascular-related diagnoses were more common and HF-related diagnoses were less common in HFpEF participants. Non-cardiovascular-related diagnoses represented the most common causes of 30-day readmission following HF hospitalization for each week of the 30-day postdischarge period. HF diagnoses were less common among those with HFpEF compared with HFrEF. Future interventions aimed at reducing 30-day readmissions following an HF hospitalization would benefit from an increased focus on noncardiovascular comorbidity and interventions that target HFpEF and HFrEF separately. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Investigation on Flexure Test of Composite Beam of Repair Materials and Substrate Concrete for Durable Repair

NASA Astrophysics Data System (ADS)

Pattnaik, Rashmi R.; Rangaraju, Prasada Rao

2014-12-01

An experimental study was conducted on composite beam of repair materials and substrate concrete to investigate the failures of concrete repair due to differences in strength of repair materials and substrate concrete. In this investigation the flexural strength, load-deflection curves and failure patterns of the composite beam specimens are studied for the durability of the concrete repair. Flexure test was conducted to simulate tensile stress in the concrete repair material. Compressive strength and split tensile strength of the repair materials and substrate concrete are investigated to aid in the analysis of the concrete repair. It was observed that the repair materials of higher compressive strength than the substrate concrete are causing an incompatible failure in the concrete repair.

Physical growth and development of the malnourished child: contributions from 50 years of research at INCAP.

PubMed

Martorell, Reynaldo

2010-03-01

This paper reviews the main findings and policy implications of 50 years (1949-1999) of research conducted by INCAP on growth and development. Topical areas reviewed include a) maternal size and birthweight and the causes of intrauterine growth retardation (IUGR), b) patterns and causes of postnatal growth retardation, c) the relative importance of genetics and the environment in explaining differences in growth among populations, d) the implications of being small, for both children and adults, e) bone growth and maturation and dental development, f) menarche, and g) methodological contributions such as anthropometric reference data, quality control of data collection, development of risk indicators and use of anthropometry in nutrition surveillance systems. Key contributions to knowledge by INCAP include a) characterization of growth failure and maturational delays as mainly occurring during the intrauterine period and the first 3 years of life b) clarification of the role of small maternal size and of inadequate dietary intakes during pregnancy as major causes of intrauterine growth failure, c) evidence that diarrheal diseases and poor dietary intakes are the principal causes of growth failure in early childhood, d) demonstration that environmental factors related to poverty, and not genetic or racial ancestry, account for most of the differences in growth between populations, e) evidence that growth failure predicts functional impairment in the child as well as in the adult andf) demonstration that nutrition interventions are effective in preventing growth failure and its consequences, if targeted to needy women and young children. INCAP's work has contributed knowledge that has informed and improved policies and programs aimed at overcoming maternal and child undernutrition and promoting optimal growth and development.

Patient Characteristics, Health Care Resource Utilization, and Costs Associated with Treatment-Regimen Failure with Biologics in the Treatment of Psoriasis.

PubMed

Foster, Shonda A; Zhu, Baojin; Guo, Jiaying; Nikai, Enkeleida; Ojeh, Clement; Malatestinic, William; Goldblum, Orin; Kornberg, Lori J; Wu, Jashin J

2016-04-01

Psoriasis is a chronic, incurable, and immune-mediated skin disorder that is characterized by erythematous scaly papules and plaques. Understanding of psoriasis at the molecular level has led to the development of biologic agents that target disease-specific inflammatory mediators in psoriatic lesions. Biologic agents have become important components of the psoriasis armamentarium, but some patients become refractory to these agents over time or fail to respond to subsequent biologics. To (a) evaluate demographic and clinical characteristics of psoriasis patients who have treatment patterns suggestive of failure to a newly initiated biologic agent (treatment-regimen failures) compared with those who do not (non-treatment-regimen failures) and (b) to assess health care-related resource utilization and costs in non-treatment-regimen failures and treatment-regimen failures. In this retrospective observational cohort study, patients were selected from the MarketScan claims database of commercially insured individuals and individuals with Medicare supplemental insurance. The index event was a newly initiated biologic agent for the treatment of psoriasis (etanercept, adalimumab, ustekinumab, or infliximab) between January 2010 and December 2011. The analysis included psoriasis patients aged ≥ 18 years with ≥ 1 prescription claim for a biologic and continuous enrollment 12 months pre- and post-index date. Patients with claims for a biologic in the pre-index period were excluded. Patients were divided into treatment-regimen-failure and non-treatment-regimen-failure groups based on their treatment patterns post-index date. The treatment-regimen-failure group included patients who switched to another biologic, discontinued the biologic without restarting, increased the dose of the biologic, or augmented treatment with a nontopical psoriasis medication during the post-index period. Between-group patient characteristics and medication use were compared using analysis of variance for continuous variables and chi-square tests for categorical variables without adjustment. Cost differences were compared using the propensity score-adjusted bin bootstrapping method. Overall, 2,146 patients met the enrollment criteria. The mean age was 45.1 years. Of these patients, 41.5% were considered treatment-regimen failures. Among treatment-regimen failures, 53% were females, and among non-treatment-regimen failures, 61% were male. Patients who experienced treatment-regimen failure had higher incidences of comorbid cerebrovascular disease, hypertension, chronic pulmonary disease, depression, and anxiety in the pre-index period and were more likely to use concomitant topicals (67.0% vs. 58.4%; P < 0.001), methotrexate (20.2% vs. 7.3%; P < 0.001), and cyclosporine (3.1% vs. 1.0%; P < 0.001) in the post-index period. Mean total all-cause health care costs were higher in patients with treatment-regimen failure versus non-treatment-regimen failure during the pre-index period ($8,024 vs. $6,637; P = 0.002), but patients with non-treatment-regimen failure had higher all-cause costs ($30,759 vs. $28,012; P = 0.002) and psoriasis-related costs ($25,286 vs. $19,625; P < 0.001) during the post-index period. The results of the current study demonstrated that psoriasis patients with treatment patterns suggestive of treatment-regimen failure on an index biologic had different characteristics and incurred higher all-cause health care costs than did patients without treatment-regimen failure during the pre-index period. This study was supported by Eli Lilly and Company. Foster, Zhu, Guo, Nikai, Malatestinic, Ojeh, and Goldblum are full-time employees and stockholders of Eli Lilly and Company. Kornberg is a full-time employee of INC Research, which was contracted by Eli Lilly to assist with medical writing. Wu has received research funding from AbbVie, Amgen, Coherus Biosciences, Eli Lilly, Janssen, Merck, Novartis, Pfizer, Regeneron, and Sandoz; he is a consultant for AbbVie, Amgen, Celgene, Dermira, DUSA Pharmaceuticals, Eli Lilly, and Pfizer. Study concept was developed by Foster, Ojeh, Malatestinic, and Goldblum. Zhu and Guo, along with Foster, took the lead in data collection, and data interpretation was performed by Nikai, Wu, and Foster, with assistance from the other authors. The manuscript was primarily written by Kornberg, along with Foster, with assistance from the other authors. All of the authors were involved with manuscript revision.

Homozygous Mutations in WEE2 Cause Fertilization Failure and Female Infertility.

PubMed

Sang, Qing; Li, Bin; Kuang, Yanping; Wang, Xueqian; Zhang, Zhihua; Chen, Biaobang; Wu, Ling; Lyu, Qifeng; Fu, Yonglun; Yan, Zheng; Mao, Xiaoyan; Xu, Yao; Mu, Jian; Li, Qiaoli; Jin, Li; He, Lin; Wang, Lei

2018-04-05

Fertilization is a fundamental process of development and is a prerequisite for successful human reproduction. In mice, although several receptor proteins have been shown to play important roles in the process of fertilization, only three genes have been shown to cause fertilization failure and infertility when deleted in vivo. In clinical practice, some infertility case subjects suffer from recurrent failure of in vitro fertilization and intracytoplasmic sperm injection attempts due to fertilization failure, but the genetic basis of fertilization failure in humans remains largely unknown. Wee2 is a key oocyte-specific kinase involved in the control of meiotic arrest in mice, but WEE2 has not been associated with any diseases in humans. In this study, we identified homozygous mutations in WEE2 that are responsible for fertilization failure in humans. All four independent affected individuals had homozygous loss-of-function missense mutations or homozygous frameshift protein-truncating mutations, and the phenotype of fertilization failure was shown to follow a Mendelian recessive inheritance pattern. All four mutations significantly decreased the amount of WEE2 protein in vitro and in affected individuals' oocytes in vivo, and they all led to abnormal serine phosphorylation of WEE2 and reduced tyrosine 15 phosphorylation of Cdc2 in vitro. In addition, injection of WEE2 cRNA into affected individuals' oocytes rescued the fertilization failure phenotype and led to the formation of blastocysts in vitro. This work presents a novel gene responsible for human fertilization failure and has implications for future therapeutic treatments for infertility cases. Copyright © 2018 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Systematic Studies of Modified Vocalization: The Effect of Speech Rate on Speech Production Measures during Metronome-Paced Speech in Persons Who Stutter

ERIC Educational Resources Information Center

Davidow, Jason H.

2014-01-01

Background: Metronome-paced speech results in the elimination, or substantial reduction, of stuttering moments. The cause of fluency during this fluency-inducing condition is unknown. Several investigations have reported changes in speech pattern characteristics from a control condition to a metronome-paced speech condition, but failure to control…

When Smart People Fail: An Analysis of the Transaction Log of an Online Public Access Catalog.

ERIC Educational Resources Information Center

Peters, Thomas A.

1989-01-01

Describes a low cost study of the transaction logs of an online catalog at an academic library that examined failure rates, usage patterns, and probable causes of patron problems. The implications of the findings for bibliographic instruction and collection development are discussed and the benefits of analyzing transaction logs are identified.…

Rate-weakening friction characterizes both slow sliding and catastrophic failure of landslides.

PubMed

Handwerger, Alexander L; Rempel, Alan W; Skarbek, Rob M; Roering, Joshua J; Hilley, George E

2016-09-13

Catastrophic landslides cause billions of dollars in damages and claim thousands of lives annually, whereas slow-moving landslides with negligible inertia dominate sediment transport on many weathered hillslopes. Surprisingly, both failure modes are displayed by nearby landslides (and individual landslides in different years) subjected to almost identical environmental conditions. Such observations have motivated the search for mechanisms that can cause slow-moving landslides to transition via runaway acceleration to catastrophic failure. A similarly diverse range of sliding behavior, including earthquakes and slow-slip events, occurs along tectonic faults. Our understanding of these phenomena has benefitted from mechanical treatments that rely upon key ingredients that are notably absent from previous landslide descriptions. Here, we describe landslide motion using a rate- and state-dependent frictional model that incorporates a nonlocal stress balance to account for the elastic response to gradients in slip. Our idealized, one-dimensional model reproduces both the displacement patterns observed in slow-moving landslides and the acceleration toward failure exhibited by catastrophic events. Catastrophic failure occurs only when the slip surface is characterized by rate-weakening friction and its lateral dimensions exceed a critical nucleation length [Formula: see text] that is shorter for higher effective stresses. However, landslides that are extensive enough to fall within this regime can nevertheless slide slowly for months or years before catastrophic failure. Our results suggest that the diversity of slip behavior observed during landslides can be described with a single model adapted from standard fault mechanics treatments.

Rate-weakening friction characterizes both slow sliding and catastrophic failure of landslides

PubMed Central

Handwerger, Alexander L.; Rempel, Alan W.; Skarbek, Rob M.; Roering, Joshua J.; Hilley, George E.

2016-01-01

Catastrophic landslides cause billions of dollars in damages and claim thousands of lives annually, whereas slow-moving landslides with negligible inertia dominate sediment transport on many weathered hillslopes. Surprisingly, both failure modes are displayed by nearby landslides (and individual landslides in different years) subjected to almost identical environmental conditions. Such observations have motivated the search for mechanisms that can cause slow-moving landslides to transition via runaway acceleration to catastrophic failure. A similarly diverse range of sliding behavior, including earthquakes and slow-slip events, occurs along tectonic faults. Our understanding of these phenomena has benefitted from mechanical treatments that rely upon key ingredients that are notably absent from previous landslide descriptions. Here, we describe landslide motion using a rate- and state-dependent frictional model that incorporates a nonlocal stress balance to account for the elastic response to gradients in slip. Our idealized, one-dimensional model reproduces both the displacement patterns observed in slow-moving landslides and the acceleration toward failure exhibited by catastrophic events. Catastrophic failure occurs only when the slip surface is characterized by rate-weakening friction and its lateral dimensions exceed a critical nucleation length h* that is shorter for higher effective stresses. However, landslides that are extensive enough to fall within this regime can nevertheless slide slowly for months or years before catastrophic failure. Our results suggest that the diversity of slip behavior observed during landslides can be described with a single model adapted from standard fault mechanics treatments. PMID:27573836

[PATHOPHYSIOLOGY OF THE CARDIORENAL SYNDROME].

PubMed

Balint, I; Vučak, J; Bašić-Marković, N; Klarić, D; Šakić, V Amerl

2016-12-01

Cardiorenal syndrome, a complex pathophysiological disorder of both the heart and kidneys, is a condition in which acute or chronic damage to one organ can lead to acute or chronic dysfunction of the other organ. Depending on primary organ dysfunction and disease duration, there are five different types of cardiorenal syndrome. Type 1 cardiorenal syndrome (acute cardiorenal syndrome) is defined as acute kidney injury caused by sudden decrease in heart function. Type 2 cardiorenal syndrome (chronic cardiorenal syndrome) refers to chronic kidney disease linked to chronic heart failure. Type 3 cardiorenal syndrome (acute renocardial syndrome) is caused by acute kidney injury that leads to heart failure. Type 4 cardiorenal syndrome (chronic renocardial syndrome) includes chronic heart failure due to chronic kidney disease. Type 5 cardiorenal syndrome (secondary cardiorenal syndrome) is reversible or irreversible condition marked by simultaneous heart and kidney insufficiency, as a result of multiorgan disease such as sepsis, diabetes mellitus, sarcoidosis, amyloidosis, etc. The pathophysiological patterns of cardiorenal syndrome are extremely complicated. Despite numerous publications, perplexed physiological, biochemical and hormonal disturbances as parts of the main pathogenic mechanisms of cardiorenal syndrome remain obscure. Even though there are guidelines for the treatment of patients with heart failure and chronic kidney disease, similar guidelines for the treatment of cardiorenal syndrome are lacking. In everyday practice, it is crucial to diagnose cardiorenal syndrome and use all diagnostic and therapeutic procedures available to prevent or alleviate kidney and heart failure.

Survivorship analysis of failure pattern after revision total hip arthroplasty.

PubMed

Retpen, J B; Varmarken, J E; Jensen, J S

1989-12-01

Failure, defined as established indication for or performed re-revision of one or both components, was analyzed using survivorship methods in 306 revision total hip arthroplasties. The longevity of revision total hip arthroplasties was inferior to that of previously reported primary total hip arthroplasties. The overall survival curve was two-phased, with a late failure period associated with aseptic loosening of one or both components and an early failure period associated with causes of failure other than loosening. Separate survival curves for aseptic loosening of femoral and acetabular components showed late and almost simultaneous decline, but with a tendency toward a higher rate of failure for the femoral component. No differences in survival could be found between the Stanmore, Lubinus standard, and Lubinus long-stemmed femoral components. A short interval between the index operation and the revision and intraoperative and postoperative complications were risk factors for early failure. Young age was a risk factor for aseptic loosening of the femoral component. Intraoperative fracture of the femoral shaft was not a risk factor for secondary loosening. No difference in survival was found between primary cemented total arthroplasty and primary noncemented hemiarthroplasty.

Kidney Failure

MedlinePlus

... store Donate Now Give Monthly Give In Honor Kidney Failure (ESRD) Causes, Symptoms, & Treatments www.kidneyfund.org > ... Disaster preparedness Kidney failure/ESRD diet What causes kidney failure? In most cases, kidney failure is caused ...

A clinical study of pattern and factors affecting outcome in Nigerian patients with advanced heart failure.

PubMed

Familoni, O B; Olunuga, T O; Olufemi, B W

2007-01-01

Advanced heart failure (AHF) accounts for about 25% of all cases of heart failure in Nigeria and is associated with a high mortality rate. To undertake a clinical study of the pattern and outcome of AHF in our hospitalised patients and to determine the parameters associated with mortality and survival in these patients. Eighty-two patients with AHF were studied between January 2003 and December 2005. Baseline blood chemistry and haemodynamics were determined. A congestion score, including orthopnoea, elevated jugular venous pressure, oedema, ascites and loud P2, was derived as well as a low perfusion score. Mortality was computed and risk estimated using the Pearson coefficient and log-ranking test. Cox regression analysis was used to identify the predictors of survival. AHF accounted for 43.6% of all hospitalised heart failure patients, with a total mortality of 67.1%. Hypertension was the commonest cause of AHF. The parameters associated with increased mortality rates included age (r = 0.671; p = 0.02), presence of atrial fibrillation (r = 0.532; p = 0.045) and estimated glomerular filtration rate (r = -0.486, p = 0.04). The majority of patients (54.8%) were in the 'wet and cold' congestion category. The congestion score correlated with mortality. The indices of survival included lower age, lower systolic blood pressure, being literate and lower congestion score. AHF was common in our cohorts of hospitalised heart failure patients and it was associated with a high mortality rate.

Teacher response to learning disability: a test of attributional principles.

PubMed

Clark, M D

1997-01-01

Attribution research has identified student ability and effort expended as causes of achievement outcomes that result in differing teacher affect, evaluative feedback, and expectation of future performance. Ninety-seven elementary-school general education teachers (84 women and 13 men) rated their responses to the test failures of hypothetical boys with and without learning disabilities. In most cases, greater reward and less punishment, less anger and more pity, and higher expectations of future failure followed the negative outcomes of the boys with learning disabilities, when compared with their nondisabled ability and effort matches, indicating that learning disability acts as a cause of achievement outcomes in the same way as ability and effort. This pattern of teacher affect and response can send negative messages that are often interpreted as low-ability cues, thus affecting students' self-esteem, sense of competence as learners, and motivation to achieve.

Skin Color and Latinos: The Origins and Contemporary Patterns of Ethnoracial Ambiguity among Mexican Americans and Puerto Ricans. Report Number 1.

ERIC Educational Resources Information Center

Montalvo, Frank F.

Failure to understand the role of skin color in the development of ethnoracial identity among Hispanic Americans has led to continued psychic and educational problems for them, hidden the cause of real and potential divisiveness in the community, and prevented the development of effective strategies for overcoming ethnic prejudice. The ethnic…

Causes of death in a contemporary adult congenital heart disease cohort.

PubMed

Yu, Christopher; Moore, Benjamin M; Kotchetkova, Irina; Cordina, Rachael L; Celermajer, David S

2018-04-17

The life expectancy of patients with congenital heart disease (CHD) has significantly improved with advances in their paediatric medical care. Mortality patterns are changing as a result. Our study aims to describe survival and causes of death in a contemporary cohort of adult patients with CHD. We reviewed 3068 patients in our adult CHD database (age ≥16 years, seen at least once in our centre between 2000 and 2015), and documented the number and causes of death, via Australia's National Death Index. Survival and mortality patterns were analysed by complexity of CHD and by underlying congenital diagnosis. Our cohort comprised 3068 adult patients (53% male). The distribution of patients (per the Bethesda classification) was 47% simple, 34% moderate and 18% complex (1% not classifiable). Over a median follow-up of 6.2 years (IQR 3.5-10.4), 341 patients (11%) died with an incidence of 0.4 deaths/100 patient years (py). Survival was significantly worse with increasing complexity of CHD (p<0.001); mortality rate in the simple group was 0.3 deaths/100 py with a median age of death 70 years, and in the complex group was 1.0 death/100 py with a median age of death 34 years. Overall, non-cardiac causes of death outnumbered cardiac causes, at 54% and 46%, respectively. The leading single cause of death was heart failure (17%), followed by malignancy (13%). Simple adult CHD patients mostly died due to non-cardiac causes such as malignancy. Perioperative mortality only accounted for 5% of deaths. Premature death is common in adults with CHD. Although heart failure remains the most common cause of death, in the contemporary era in a specialist CHD centre, non-cardiac related deaths outnumber cardiac deaths, particularly in those with simple CHD lesions. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Failure modes of microstructured fibers with sacrificial bonds made by instability-assisted 3D printing

NASA Astrophysics Data System (ADS)

Zou, Shibo; Therriault, Daniel; Gosselin, Frederick

A simple modification by increasing the deposition height on a commercially available 3D printer makes it a mechanical sewing machine due to the fluid mechanical instability. A variety of stitches-like patterns can be produced, similar to those by the Newtonian fluid mechanical sewing machine\\x9D, but with more interesting characteristics in the additional third dimension, which creates weakly fused bonds in some patterns. With these bonds, the fabricated fibers exhibit improved toughness in uniaxial tensile test. The toughening mechanism is found to be similar to the one in spider silk - the breaking of sacrificial bonds and the releasing of hidden length contribute significant dissipated energy to the system. However, the mechanical performance of these microstructured fibers is restricted by early fiber breakage as the number of sacrificial bonds increases. Here, we seek to understand the failure mechanisms of the microstructured fibers through tensile tests and finite element simulations. Static and dynamic failure are both found to cause early fiber breakage. These findings are helpful for the design optimization of microstructured fibers with high toughness and ductility, which can find potential use in impact protection and safety-critical applications.

Common Cause Failures and Ultra Reliability

NASA Technical Reports Server (NTRS)

Jones, Harry W.

2012-01-01

A common cause failure occurs when several failures have the same origin. Common cause failures are either common event failures, where the cause is a single external event, or common mode failures, where two systems fail in the same way for the same reason. Common mode failures can occur at different times because of a design defect or a repeated external event. Common event failures reduce the reliability of on-line redundant systems but not of systems using off-line spare parts. Common mode failures reduce the dependability of systems using off-line spare parts and on-line redundancy.

Rate-weakening friction characterizes both slow sliding and catastrophic failure of landslides

NASA Astrophysics Data System (ADS)

Handwerger, Alexander L.; Rempel, Alan W.; Skarbek, Rob M.; Roering, Joshua J.; Hilley, George E.

2016-09-01

Catastrophic landslides cause billions of dollars in damages and claim thousands of lives annually, whereas slow-moving landslides with negligible inertia dominate sediment transport on many weathered hillslopes. Surprisingly, both failure modes are displayed by nearby landslides (and individual landslides in different years) subjected to almost identical environmental conditions. Such observations have motivated the search for mechanisms that can cause slow-moving landslides to transition via runaway acceleration to catastrophic failure. A similarly diverse range of sliding behavior, including earthquakes and slow-slip events, occurs along tectonic faults. Our understanding of these phenomena has benefitted from mechanical treatments that rely upon key ingredients that are notably absent from previous landslide descriptions. Here, we describe landslide motion using a rate- and state-dependent frictional model that incorporates a nonlocal stress balance to account for the elastic response to gradients in slip. Our idealized, one-dimensional model reproduces both the displacement patterns observed in slow-moving landslides and the acceleration toward failure exhibited by catastrophic events. Catastrophic failure occurs only when the slip surface is characterized by rate-weakening friction and its lateral dimensions exceed a critical nucleation length h*h* that is shorter for higher effective stresses. However, landslides that are extensive enough to fall within this regime can nevertheless slide slowly for months or years before catastrophic failure. Our results suggest that the diversity of slip behavior observed during landslides can be described with a single model adapted from standard fault mechanics treatments.

[Cheyne-Stokes respiration and cardiovascular risk].

PubMed

Duchna, H-W; Schultze-Werninghaus, G

2009-07-01

Due to its high prevalence in patients with heart failure and its negative predictive value concerning morbidity and mortality, Cheyne-Stokes respiration (CSR) is a sleep disorders of major interest. CSR correlates with the degree of heart failure and is characterised by a typical crescendo/decrescendo breathing pattern combined with phases of central sleep apnoea, caused by pulmonary oedema and oscillation of ventilatory control. Thus, CSR is a marker of the severity of heart failure. Treatment of CSR first involves optimisation of heart failure therapy by cardiologists and then application of non-invasive means of ventilatory support. Treatment of patients with severe heart failure with non-invasive positive pressure ventilatory support leads to a significant reduction of CSR, sympathetic activity, and daytime sleepiness and improves cardiac output and 6-minute walking distance. At present, a prospective randomised, controlled intervention-study (Serve-HF study) is being conducted in order to show if therapy of CSR can improve patient survival. This review describes the pathophysiology, epidemiology, and therapeutic options of CSR with a special focus on the elevated cardiovascular risk of patients with CSR.

The Six Minute Walk Test Revisited

NASA Astrophysics Data System (ADS)

Mazumder, M.

2017-12-01

Background and Purpose: Heart failure is the leading cause of death and often alters or severely restricts human mobility, an essential life function. Motion capture is an emerging tool for analyzing human movement and extremity articulation, providing quantitative information on gait and range of motion. This study uses BioStamp mechanosensors to identify differences in motion for the duration of the Six Minute Walk Test and signature patterns of muscle contraction and posture in patients with advanced heart failure compared to healthy subjects. Identification and close follow up of these patterns may allow enhanced diagnosis and the possibility for early intervention before disease worsening. Additionally, movement parameters represent a new family of potential biomarkers to track heart failure onset, progression and therapy. Methods: Prior to the Six Minute Walk Test, BioStamps (MC10) were applied to the chest, upper and lower extremities of heart failure and healthy patients and data were streamed and recorded revealing the pattern of movement in three separate axes. Conjointly, before and after the Six Minute Walk Test, the following vitals were measured per subject: heart rate, respiratory rate, blood pressure, oxygen saturation, dyspnea and leg fatigue (self-reported with Borg scale). During the test, patients were encouraged to walk as far as they can in 6 minutes on a 30m course, as we recorded the number of laps completed and oxygen saturation every minute. Results and Conclusions: The sensors captured and quantified whole body and regional motion parameters including: a. motion extent, position, acceleration and angle via incorporated accelerometers and gyroscopes; b. muscle contraction via incorporated electromyogram (EMG). Accelerometry and gyroscopic data for the last five steps of a healthy and heart failure patient are shown. While significant differences in motion for the duration of the test were not found, each category of patients had a distinct pattern of motion - with identifiable qualitative and quantitative differences. These wearable conformal skin adherent sensors allow on-body, mobile, personalized determination of motion and flexibility parameters. This tool and method hold promise for providing motion "biomarker" data in health and disease.

Riser Blood Pressure Pattern Is Associated With Mild Cognitive Impairment in Heart Failure Patients.

PubMed

Komori, Takahiro; Eguchi, Kazuo; Saito, Toshinobu; Nishimura, Yoshioki; Hoshide, Satoshi; Kario, Kazuomi

2016-02-01

The riser pattern, an abnormal blood pressure (BP) rhythm in which sleep BP exceeds awake BP, is a predictor of future stroke events. Although the riser pattern is caused by autonomic dysfunction, its significance in heart failure (HF) patients is not established. HF patients often suffered from cognitive impairment (CI), but the relationship between riser pattern and CI is not clearly understood. We tested the hypothesis that the riser pattern is associated with mild CI, a form of brain damage that could develop to dementia. We performed Mini-Mental State Examination (MMSE), ambulatory BP monitoring (ABPM), echocardiography, and blood tests in 444 HF patients just before leaving hospitals. Mild CI, a measure of cognitive function, was defined as the score <26. The mean age of the patients was 68±13 years; 61.5% were male; 22.5% were riser pattern. The MMSE score was significantly lower in the Riser group than in the Non-dipper and Dipper group (23±4 vs. 25±5, 26±4, respectively, P < 0.01). In multivariable logistic regression analysis, a riser pattern was significantly associated with mild CI (odds ratio 2.38, 95% confidence intervals 1.29-4.42, P < 0.01) after adjusting for significant covariates. The riser pattern was associated with mild CI in HF patients. An abnormal circadian BP rhythm in HF patients is clinically significant as a potential indicator of subclinical brain damage. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Hot (Invisible?) Hand: Can Time Sequence Patterns of Success/Failure in Sports Be Modeled as Repeated Random Independent Trials?

PubMed Central

Yaari, Gur; Eisenmann, Shmuel

2011-01-01

The long lasting debate initiated by Gilovich, Vallone and Tversky in is revisited: does a “hot hand” phenomenon exist in sports? Hereby we come back to one of the cases analyzed by the original study, but with a much larger data set: all free throws taken during five regular seasons () of the National Basketball Association (NBA). Evidence supporting the existence of the “hot hand” phenomenon is provided. However, while statistical traces of this phenomenon are observed in the data, an open question still remains: are these non random patterns a result of “success breeds success” and “failure breeds failure” mechanisms or simply “better” and “worse” periods? Although free throws data is not adequate to answer this question in a definite way, we speculate based on it, that the latter is the dominant cause behind the appearance of the “hot hand” phenomenon in the data. PMID:21998630

Patterns and Predictors of Failed and Sustained Return-to-Work in Transport Injury Insurance Claimants.

PubMed

Gray, Shannon E; Hassani-Mahmooei, Behrooz; Cameron, Ian D; Kendall, Elizabeth; Kenardy, Justin; Collie, Alex

2018-02-12

Purpose To determine the incidence of employed people who try and fail to return-to-work (RTW) following a transport crash. To identify predictors of RTW failure. A historical cohort study was conducted in the state of Victoria, Australia. People insured through the state-based compulsory third party transport accident compensation scheme were included. Inclusion criteria included date of crash between 2003 and 2012 (inclusive), age 15-70 years at the time of crash, sustained a non-catastrophic injury and received at least 1 day of income replacement. A matrix was created from an administrative payments dataset that mapped their RTW pattern for each day up to 3 years' post-crash. A gap of 7 days of no payment followed by resumption of a payment was considered a RTW failure and was flagged. These event flags were then entered into a regression analysis to determine the odds of having a failed RTW attempt. 17% of individuals had a RTW fail, with males having 20% lower odds of experiencing RTW failure. Those who were younger, had minor injuries (sprains, strains, contusions, abrasions, non-limb fractures), or were from more advantaged socio-economic group, were less likely to experience a RTW failure. Most likely to experience a RTW failure were individuals with whiplash, dislocations or particularly those admitted to hospital. Understanding the causes and predictors of failed RTW can help insurers, employers and health systems identify at-risk individuals. This can enable earlier and more targeted support and more effective employment outcomes.

Distributed phased array architecture study

NASA Technical Reports Server (NTRS)

Bourgeois, Brian

1987-01-01

Variations in amplifiers and phase shifters can cause degraded antenna performance, depending also on the environmental conditions and antenna array architecture. The implementation of distributed phased array hardware was studied with the aid of the DISTAR computer program as a simulation tool. This simulation provides guidance in hardware simulation. Both hard and soft failures of the amplifiers in the T/R modules are modeled. Hard failures are catastrophic: no power is transmitted to the antenna elements. Noncatastrophic or soft failures are modeled as a modified Gaussian distribution. The resulting amplitude characteristics then determine the array excitation coefficients. The phase characteristics take on a uniform distribution. Pattern characteristics such as antenna gain, half power beamwidth, mainbeam phase errors, sidelobe levels, and beam pointing errors were studied as functions of amplifier and phase shifter variations. General specifications for amplifier and phase shifter tolerances in various architecture configurations for C band and S band were determined.

Causes and correlates of anemia in 200 patients with acute cardiogenic pulmonary edema.

PubMed

Rovellini, Angelo; Graziadei, Giovanna; Folli, Christian; Brambilla, Anna Maria; Cosentini, Roberto; Canetta, Ciro; Monzani, Valter

2012-12-01

Acute heart failure has a poor prognosis and the presence of anemia may increase the risk of adverse outcomes. However, the clinical and laboratory characteristics of anemia in acute heart failure are poorly known. We aimed to assess the causes and the clinical and laboratory correlates of anemia in patients with acute cardiogenic pulmonary edema (ACPE). This observational study, performed in an Emergency Unit, enrolled 200 patients treated with medical therapy and continuous positive airway pressure. Anemia was found in 36% of patients (38.5% of females and 32.5% of males) and was severe (hemoglobin <9 g/dL) in 6.9% of cases. The most frequent causes of anemia were chronic renal failure (27.8%), chronic inflammatory states (27.8%) and the clustering of multiple factors (18.1%). A wider spectrum of etiological factors was found in females than in males. Microcytic anemia was observed only in females (20% of those anemic), mainly due to iron deficiency/chronic blood loss. Glomerular filtration rate, serum iron, serum albumin, total cholesterol and diastolic blood pressure were independently associated with hemoglobin levels. The etiology of anemia in ACPE is heterogeneous, with several causal factors besides impaired renal function. The pattern of anemia is different between genders, suggesting that sex-specific diagnostic and therapeutic targets should be implemented. Copyright © 2012 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Asymmetrical booster guidance and control system design study. Volume 3: Space shuttle vehicle SRB actuator failure study. [space shuttle development

NASA Technical Reports Server (NTRS)

Williams, F. E.; Lemon, R. S.

1974-01-01

The investigation of single actuator failures on the space shuttle solid rocket booster required the analysis of both square pattern and diamond pattern actuator configurations. It was determined that for failures occuring near or prior to the region of maximum dynamic pressure, control gain adjustments can be used to achieve virtually nominal mid-boost vehicle behavior. A distinct worst case failure condition was established near staging that could significantly delay staging. It is recommended that the square pattern be retained as a viable alternative to the baseline diamond pattern because the staging transient is better controlled resulting in earlier staging.

The phenoptosis problem: what is causing the death of an organism? Lessons from acute kidney injury.

PubMed

Zorov, D B; Plotnikov, E Y; Jankauskas, S S; Isaev, N K; Silachev, D N; Zorova, L D; Pevzner, I B; Pulkova, N V; Zorov, S D; Morosanova, M A

2012-07-01

Programmed execution of various cells and intracellular structures is hypothesized to be not the only example of elimination of biological systems - the general mechanism can also involve programmed execution of organs and organisms. Modern rating of programmed cell death mechanisms includes 13 mechanistic types. As for some types, the mechanism of actuation and manifestation of cell execution has been basically elucidated, while the causes and intermediate steps of the process of fatal failure of organs and organisms remain unknown. The analysis of deaths resulting from a sudden heart arrest or multiple organ failure and other acute and chronic pathologies leads to the conclusion of a special role of mitochondria and oxidative stress activating the immune system. Possible mechanisms of mitochondria-mediated induction of the signaling cascades involved in organ failure and death of the organism are discussed. These mechanisms include generation of reactive oxygen species and damage-associated molecular patterns in mitochondria. Some examples of renal failure-induced deaths are presented with mechanisms and settings determined by some hypothetical super system rather than by the kidneys themselves. This system plays the key role in the process of physiological senescence and termination of an organism. The facts presented suggest that it is the immune system involved in mitochondrial signaling that can act as the system responsible for the organism's death.

Episodes of breathlessness: types and patterns - a qualitative study exploring experiences of patients with advanced diseases.

PubMed

Simon, Steffen T; Higginson, Irene J; Benalia, Hamid; Gysels, Marjolein; Murtagh, Fliss Em; Spicer, James; Bausewein, Claudia

2013-06-01

Despite the high prevalence and impact of episodic breathlessness, information about characteristics and patterns is scarce. To explore the experience of patients with advanced disease suffering from episodic breathlessness, in order to describe types and patterns. Qualitative design using in-depth interviews with patients suffering from advanced stages of chronic heart failure, chronic obstructive pulmonary disease, lung cancer or motor neurone disease. As part of the interviews, patients were asked to draw a graph to illustrate typical patterns of breathlessness episodes. Interviews were tape-recorded, transcribed verbatim and analysed using Framework Analysis. The graphs were grouped according to their patterns. Fifty-one participants (15 chronic heart failure, 14 chronic obstructive pulmonary disease, 13 lung cancer and 9 motor neurone disease) were included (mean age 68.2 years, 30 of 51 men, mean Karnofsky 63.1, mean breathlessness intensity 3.2 of 10). Five different types of episodic breathlessness were described: triggered with normal level of breathlessness, triggered with predictable response (always related to trigger level, e.g. slight exertion causes severe breathlessness), triggered with unpredictable response (not related to trigger level), non-triggered attack-like (quick onset, often severe) and wave-like (triggered or non-triggered, gradual onset). Four patterns of episodic breathlessness could be identified based on the graphs with differences regarding onset and recovery of episodes. These did not correspond with the types of breathlessness described before. Patients with advanced disease experience clearly distinguishable types and patterns of episodic breathlessness. The understanding of these will help clinicians to tailor specific management strategies for patients who suffer from episodes of breathlessness.

Pharmacotherapy Treatment Patterns, Outcomes, and Health Resource Utilization Among Patients with Heart Failure with Reduced Ejection Fraction at a U.S. Academic Medical Center.

PubMed

Bress, Adam P; King, Jordan B; Brixner, Diana; Kielhorn, Adrian; Patel, Harshali K; Maya, Juan; Lee, Vinson C; Biskupiak, Joseph; Munger, Mark

2016-02-01

To assess clinical characteristics, pharmacotherapy treatment patterns, resource utilization and associated charges, and morbidity and mortality outcomes among a real-world cohort of patients with heart failure with reduced ejection fraction (HFrEF) in an academic medical center setting. Retrospective analysis. Electronic health record database that includes clinical, laboratory, and administrative data for all facilities of the University of Utah Health Care System. A total of 989 adults with prevalent (preexisting) HFrEF, identified by using the International Classification of Diseases, Ninth Revision, Clinical Modification code 428.x (heart failure) between January 1, 2007, and June 30, 2013, and who had a left ventricular ejection fraction of 40% or lower. The cohort had a mean age of 64 ± 15 years and was predominantly white (71%) and male (74%). Patients received β-blockers, angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs), and aldosterone receptor antagonists (ARAs) at rates of 79%, 69%, and 29%, respectively. Patients achieved target doses of β-blockers, ACEIs, and ARBs at rates of only 24%, 31%, and 13%, respectively. Overall, 58% of patients were prescribed dual therapy with a β-blocker and an ACEI or ARB, and 19% were prescribed triple therapy (β-blocker, an ACEI or ARB, and an ARA). Univariate and multivariate logistic regression models were used to assess the association between baseline characteristics with the presence of triple therapy. Two variables were statistically significant in both models: increasing age was associated with a lower odds of triple therapy (univariate: odds ratio [OR] 0.760, 95% confidence interval [CI] 0.673-0.857; multivariate: OR 0.768, 95% CI 0.625-0.942), whereas receipt of an implantable cardiac device was associated with a 2-fold increase in the odds of triple therapy (univariate: OR 2.1, 95% CI 1.4-3.1; multivariate: OR 2.1, 95% CI 1.3-3.5). During a mean ± SD follow-up of 36 ± 27 months, all-cause mortality was 0.12 per person-year. There were 1311 all-cause hospitalizations of which 611 (47%) were for worsening heart failure. The rate of all-cause and heart failure-specific hospitalizations was 0.44 and 0.21 per person-year of follow-up, respectively. The median length of stay was 6.4 ± 8.8 days, and the median charge was $22,310. The 30-day all-cause readmission rate was 20%, and the primary reason for readmission was heart failure in 65% of cases. This study demonstrates the continuing significant disease and economic burden for patients with HFrEF. Challenges remain in utilization of established disease-modifying therapy and in the treatment of patients with HFrEF and multiple comorbidities. © 2016 Pharmacotherapy Publications, Inc.

Chronobiology of death in heart failure.

PubMed

Ribas, Nuria; Domingo, Maite; Gastelurrutia, Paloma; Ferrero-Gregori, Andreu; Rull, Pilar; Noguero, Mariana; Garcia, Carmen; Puig, Teresa; Cinca, Juan; Bayes-Genis, Antoni

2014-05-01

In the general population, heart events occur more often during early morning, on Mondays, and during winter. However, the chronobiology of death in heart failure has not been analyzed. The aim of this study was to determine the circadian, day of the week, and seasonal variability of all-cause mortality in chronic heart failure. This was an analysis of all consecutive heart failure patients followed in a heart failure unit from January 2003 to December 2008. The circadian moment of death was analyzed at 6-h intervals and was determined by reviewing medical records and by information provided by the relatives. Of 1196 patients (mean [standard deviation] age, 69 [13] years; 62% male), 418 (34.9%) died during a mean (standard deviation) follow-up of 29 (21) months. Survivors were younger, had higher body mass index, left ventricular ejection fraction, glomerular filtration rate, hemoglobin and sodium levels, and lower Framingham risk scores, amino-terminal pro-B type natriuretic peptide, troponin T, and urate values. They were more frequently treated with angiotensin receptor blockers, beta-blockers, mineralocorticoids receptor antagonists, digoxin, nitrates, hydralazine, statins, loop diuretics, and thiazides. The analysis of the circadian and weekly variability did not reveal significant differences between the four 6-h intervals or the days of the week. Mortality occurred more frequently during the winter (30.6%) compared with the other seasons (P = .024). All cause mortality does not follow a circadian pattern, but a seasonal rhythm in patients with heart failure. This finding is in contrast to the circadian rhythmicity of cardiovascular events reported in the general population. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Common Cause Failure Modeling: Aerospace Versus Nuclear

NASA Technical Reports Server (NTRS)

Stott, James E.; Britton, Paul; Ring, Robert W.; Hark, Frank; Hatfield, G. Spencer

2010-01-01

Aggregate nuclear plant failure data is used to produce generic common-cause factors that are specifically for use in the common-cause failure models of NUREG/CR-5485. Furthermore, the models presented in NUREG/CR-5485 are specifically designed to incorporate two significantly distinct assumptions about the methods of surveillance testing from whence this aggregate failure data came. What are the implications of using these NUREG generic factors to model the common-cause failures of aerospace systems? Herein, the implications of using the NUREG generic factors in the modeling of aerospace systems are investigated in detail and strong recommendations for modeling the common-cause failures of aerospace systems are given.

A multi-sensor approach to landslide monitoring of rainfall-induced failures in Scotland.

NASA Astrophysics Data System (ADS)

Gilles, Charlie; Hoey, Trevor; Williams, Richard

2017-04-01

Landslides are of significant interest in upland areas of the United Kingdom due to their: complex mechanics, potential to channelize into hazardous debris flows and their costly potential impacts on infrastructure. The British Geological Survey National Landslide Database contains an average of 367 landslides per year (from 1970). Slope failures in the UK are typically triggered by extended periods of intense rainfall, and can occur at any time of year. In any given rainfall event that triggers landslides, most potentially vulnerable slopes remain stable. Accurate warning systems would be facilitated by identifying landslide precursors prior to failure events. This project tests whether such precursors can be identified in the valley of Glen Ogle, Scotland (87 km north-west of Edinburgh), where in summer 2004 two debris flows blocked the main road (A85), trapping fifty-seven people. Two adjacent sites have been selected on a west facing slope in Glen Ogle, one of which (the control) has been stable since at least 2004 and the other failed in 2004 and remains unstable. Understanding the immediate causes and antecedent conditions responsible for landslides requires a multi-scale approach. This project uses multiple sensors to assess failure mechanisms of landslides in Glen Ogle: (1) 3-monthly, high (1.8 arcsec) resolution terrestrial laser scanning of topography to detect changes and identify patterns of movement prior to major failure, using the Riegl VZ-1000 (NERC Geophysical Equipment Fund); (2) rainfall and soil moisture data to monitor pore pressure of landslide failure prior to and after hydrologically triggered events; (3) monitoring ground motion using grain-scale sensors which are becoming lower cost, more efficient in terms of power, and can be wirelessly networked these will be used to detect small scale movement of the landslide. Comparative data from the control and test sites will be presented, from which patterns of surface deformation between failure events will be derived.

Tectonic lineations and frictional faulting on a relatively simple body (Ariel)

NASA Astrophysics Data System (ADS)

Nyffenegger, Paul; Davis, Dan M.; Consolmagno, Guy J.

1997-09-01

Anderson's model of faulting and the Mohr-Coulomb failure criterion can predict the orientations of faults generated in laboratory triaxial compression experiments, but do a much poorer job of explaining the orientations of outcrop- and map-scale faults on Earth. This failure may be due to the structural complexity of the Earth's lithosphere, the failure of laboratory experiments to predict accurately the strength of natural faults, or some fundamental flaw in the model. A simpler environment, such as the lithosphere of an icy satellite, allows us to test whether this model can succeed in less complex settings. A mathematical method is developed to analyze patterns in fracture orientations that can be applied to fractures in the lithospheres of icy satellites. In a initial test of the method, more than 300 lineations on Uranus' satellite Ariel are examined. A nonrandom pattern of lineations is looked for, and the source of the stresses that caused those features and the strength of the material in which they occur are constrained. It is impossible to observe directly the slip on these fractures. However, their orientations are clearly nonrandom and appear to be consistent with Andersonian strike-slip faulting in a relatively weak frictional lithosphere during one or more episodes of tidal flexing.

Causes of corneal graft failure in India.

PubMed

Dandona, L; Naduvilath, T J; Janarthanan, M; Rao, G N

1998-09-01

The success of corneal grafting in visual rehabilitation of the corneal blind in India depends on survival of the grafts. Understanding the causes of graft failure may help reduce the risk of failure. We studied these causes in a series of 638 graft failures at our institution. Multivariate logistic regression analysis was used to evaluate the association of particular causes of graft failure with indications for grafting, socioeconomic status, age, sex, host corneal vascularization, donor corneal quality, and experience of surgeon. The major causes of graft failure were allograft rejection (29.2%), increased intraocular pressure (16.9%), infection excluding endophthalmitis (15.4%), and surface problems (12.7%). The odds of infection causing graft failure were significantly higher in patients of lower socioeconomic status (odds ratio 2.45, 95% CI 1.45-4.15). Surface problems as a cause of graft failure was significantly associated with grafts done for corneal scarring or for regrafts (odds ratio 3.36, 95% CI 1.80-6.30). Increased intraocular pressure as a cause of graft failure had significant association with grafts done for aphakic or pseudophakic bullous keratopathy, congenital conditions or glaucoma, or regrafts (odds ratio 2.19, 95% CI 1.25-3.84). Corneal dystrophy was the indication for grafting in 12 of the 13 cases of graft failure due to recurrence of host disease. Surface problems, increased intraocular pressure, and infection are modifiable risk factors that are more likely to cause graft failure in certain categories of patients in India. Knowledge about these associations can be helpful in looking for and aggressively treating these modifiable risk factors in the at-risk categories of corneal graft patients. This can possibly reduce the chance of graft failure.

Evidence that failure of osteoid bone matrix resorption is caused by perturbation of osteoclast polarization.

PubMed

Yovich, S; Seydel, U; Papadimitriou, J M; Nicholson, G C; Wood, D J; Zheng, M H

1998-04-01

Osteoclasts resorb bone by a complex dynamic process that initially involves attachment, polarization and enzyme secretion, followed by their detachment and migration to new sites. In this study, we postulated that mineralized and osteoid bone matrix signal osteoclasts differently, resulting in the resorption of mineralized bone matrix only. We, therefore, compared the cytoplasmic distribution of cytoskeletal proteins F-actin and vinculin using confocal laser-scanning microscopy in osteoclasts cultured on mineralized and demineralized bone slices and correlated the observations with their functional activity. Our results have demonstrated significant differences in F-actin and vinculin staining patterns between osteoclasts cultured on mineralized bone matrix and those on demineralized bone matrix. In addition, the structural variations were accompanied by significant differences in bone resorbing activity between osteoclasts grown on mineralized bone matrix and those on demineralized bone matrix after 24 h of culture --resorption only occurring in mineralized bone but not in demineralized bone. These results indicated that failure of osteoid bone resorption is caused by perturbation of osteoclast polarization.

Accelerated Aging Experiments for Capacitor Health Monitoring and Prognostics

NASA Technical Reports Server (NTRS)

Kulkarni, Chetan S.; Celaya, Jose Ramon; Biswas, Gautam; Goebel, Kai

2012-01-01

This paper discusses experimental setups for health monitoring and prognostics of electrolytic capacitors under nominal operation and accelerated aging conditions. Electrolytic capacitors have higher failure rates than other components in electronic systems like power drives, power converters etc. Our current work focuses on developing first-principles-based degradation models for electrolytic capacitors under varying electrical and thermal stress conditions. Prognostics and health management for electronic systems aims to predict the onset of faults, study causes for system degradation, and accurately compute remaining useful life. Accelerated life test methods are often used in prognostics research as a way to model multiple causes and assess the effects of the degradation process through time. It also allows for the identification and study of different failure mechanisms and their relationships under different operating conditions. Experiments are designed for aging of the capacitors such that the degradation pattern induced by the aging can be monitored and analyzed. Experimental setups and data collection methods are presented to demonstrate this approach.

Failure mechanisms of single-crystal silicon electrodes in lithium-ion batteries

PubMed Central

Shi, Feifei; Song, Zhichao; Ross, Philip N.; Somorjai, Gabor A.; Ritchie, Robert O.; Komvopoulos, Kyriakos

2016-01-01

Long-term durability is a major obstacle limiting the widespread use of lithium-ion batteries in heavy-duty applications and others demanding extended lifetime. As one of the root causes of the degradation of battery performance, the electrode failure mechanisms are still unknown. In this paper, we reveal the fundamental fracture mechanisms of single-crystal silicon electrodes over extended lithiation/delithiation cycles, using electrochemical testing, microstructure characterization, fracture mechanics and finite element analysis. Anisotropic lithium invasion causes crack initiation perpendicular to the electrode surface, followed by growth through the electrode thickness. The low fracture energy of the lithiated/unlithiated silicon interface provides a weak microstructural path for crack deflection, accounting for the crack patterns and delamination observed after repeated cycling. On the basis of this physical understanding, we demonstrate how electrolyte additives can heal electrode cracks and provide strategies to enhance the fracture resistance in future lithium-ion batteries from surface chemical, electrochemical and material science perspectives. PMID:27297565

Failure mechanisms of single-crystal silicon electrodes in lithium-ion batteries

DOE PAGES

Shi, Feifei; Song, Zhichao; Ross, Philip N.; ...

2016-06-14

Long-term durability is a major obstacle limiting the widespread use of lithium-ion batteries in heavy-duty applications and others demanding extended lifetime. As one of the root causes of the degradation of battery performance, the electrode failure mechanisms are still unknown. In this paper, we reveal the fundamental fracture mechanisms of single-crystal silicon electrodes over extended lithiation/delithiation cycles, using electrochemical testing, microstructure characterization, fracture mechanics and finite element analysis. Anisotropic lithium invasion causes crack initiation perpendicular to the electrode surface, followed by growth through the electrode thickness. The low fracture energy of the lithiated/unlithiated silicon interface provides a weak microstructural pathmore » for crack deflection, accounting for the crack patterns and delamination observed after repeated cycling. On the basis of this physical understanding, we demonstrate how electrolyte additives can heal electrode cracks and provide strategies to enhance the fracture resistance in future lithium-ion batteries from surface chemical, electrochemical and material science perspectives.« less

Failure mechanisms of single-crystal silicon electrodes in lithium-ion batteries

NASA Astrophysics Data System (ADS)

Shi, Feifei; Song, Zhichao; Ross, Philip N.; Somorjai, Gabor A.; Ritchie, Robert O.; Komvopoulos, Kyriakos

2016-06-01

Long-term durability is a major obstacle limiting the widespread use of lithium-ion batteries in heavy-duty applications and others demanding extended lifetime. As one of the root causes of the degradation of battery performance, the electrode failure mechanisms are still unknown. In this paper, we reveal the fundamental fracture mechanisms of single-crystal silicon electrodes over extended lithiation/delithiation cycles, using electrochemical testing, microstructure characterization, fracture mechanics and finite element analysis. Anisotropic lithium invasion causes crack initiation perpendicular to the electrode surface, followed by growth through the electrode thickness. The low fracture energy of the lithiated/unlithiated silicon interface provides a weak microstructural path for crack deflection, accounting for the crack patterns and delamination observed after repeated cycling. On the basis of this physical understanding, we demonstrate how electrolyte additives can heal electrode cracks and provide strategies to enhance the fracture resistance in future lithium-ion batteries from surface chemical, electrochemical and material science perspectives.

A systems engineering approach to automated failure cause diagnosis in space power systems

NASA Technical Reports Server (NTRS)

Dolce, James L.; Faymon, Karl A.

1987-01-01

Automatic failure-cause diagnosis is a key element in autonomous operation of space power systems such as Space Station's. A rule-based diagnostic system has been developed for determining the cause of degraded performance. The knowledge required for such diagnosis is elicited from the system engineering process by using traditional failure analysis techniques. Symptoms, failures, causes, and detector information are represented with structured data; and diagnostic procedural knowledge is represented with rules. Detected symptoms instantiate failure modes and possible causes consistent with currently held beliefs about the likelihood of the cause. A diagnosis concludes with an explanation of the observed symptoms in terms of a chain of possible causes and subcauses.

Clinical benefit of cardiac resynchronization therapy with a defibrillator in patients with an ejection fraction > 35% estimated by cardiac magnetic resonance.

PubMed

Fabregat-Andrés, Oscar; García-González, Pilar; Valle-Muñoz, Alfonso; Estornell-Erill, Jordi; Pérez-Boscá, Leandro; Palanca-Gil, Victor; Payá-Serrano, Rafael; Quesada-Dorador, Aurelio; Morell, Salvador; Ridocci-Soriano, Francisco

2014-02-01

Cardiac resynchronization therapy with a defibrillator prolongs survival and improves quality of life in advanced heart failure. Traditionally, patients with ejection fraction > 35 estimated by echocardiography have been excluded. We assessed the prognostic impact of this therapy in a group of patients with severely depressed systolic function as assessed by echocardiography but with an ejection fraction > 35% as assessed by cardiac magnetic resonance. We analyzed consecutive patients admitted for decompensated heart failure between 2004 and 2011. The patients were in functional class II-IV, with a QRS ≥ to 120 ms, ejection fraction ≤ 35% estimated by echocardiography, and a cardiac magnetic resonance study. We included all patients (n=103) who underwent device implantation for primary prevention. Ventricular arrhythmia, all-cause mortality and readmission for heart failure were considered major cardiac events. The patients were divided into 2 groups according to systolic function assessed by magnetic resonance. The 2 groups showed similar improvements in functional class and ejection fraction at 6 months. We found a nonsignificant trend toward a higher risk of all-cause mortality in patients with systolic function ≤ 35% at long-term follow-up. The presence of a pattern of necrosis identified patients with a worse prognosis for ventricular arrhythmias and mortality in both groups. We conclude that cardiac resynchronization therapy with a defibrillator leads to a similar clinical benefit in patients with an ejection fraction ≤ 35% or > 35% estimated by cardiac magnetic resonance. Analysis of the pattern of late gadolinium enhancement provides additional information on arrhythmic risk and long-term prognosis. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Statistical analysis of field data for aircraft warranties

NASA Astrophysics Data System (ADS)

Lakey, Mary J.

Air Force and Navy maintenance data collection systems were researched to determine their scientific applicability to the warranty process. New and unique algorithms were developed to extract failure distributions which were then used to characterize how selected families of equipment typically fails. Families of similar equipment were identified in terms of function, technology and failure patterns. Statistical analyses and applications such as goodness-of-fit test, maximum likelihood estimation and derivation of confidence intervals for the probability density function parameters were applied to characterize the distributions and their failure patterns. Statistical and reliability theory, with relevance to equipment design and operational failures were also determining factors in characterizing the failure patterns of the equipment families. Inferences about the families with relevance to warranty needs were then made.

Two cases of malignant hypertension with reversible diffuse leukoencephalopathy exhibiting a reversible nocturnal blood pressure "riser" pattern.

PubMed

Eguchi, Kazuo; Kasahara, Kentaro; Nagashima, Akinori; Mor, Tadashi; Nii, Takanobu; Ibaraki, Kazuo; Kario, Kazuomi; Shimada, Kazuyuki

2002-05-01

We report two cases of malignant hypertension with reversible diffuse leukoencephalopathy demonstrating a nocturnal blood pressure (BP) rising pattern ("riser" pattern). Case 1 was a 54-year-old man diagnosed with malignant hypertension who presented with diffuse leukoencephalopathy and nocturnal BP rise during the acute phase. These abnormal findings diminished after treatment of hypertension. Case 2 was a 50-year-old woman diagnosed with malignant hypertension in association with leukoencephalopathy, heart failure and acute renal failure. She also presented with a "riser" pattern during the acute phase. In contrast to case 1, the leukoencephalopathy and "riser" pattern in case 2 were not improved even after 1 month of treatment. Following intensive antihypertensive treatment, renal failure was improved in case 1, but renal failure was not improved after 1 month in case 2. In conclusion, a possible explanation of this phenomenon is that a causative volume overload due to renal dysfunction produced the temporal leukoencephalopathy-like brain edema and "riser" pattern in these cases.

Load to Failure and Stiffness

PubMed Central

Esquivel, Amanda O.; Duncan, Douglas D.; Dobrasevic, Nikola; Marsh, Stephanie M.; Lemos, Stephen E.

2015-01-01

Background: Rotator cuff tendinopathy is a frequent cause of shoulder pain that can lead to decreased strength and range of motion. Failures after using the single-row technique of rotator cuff repair have led to the development of the double-row technique, which is said to allow for more anatomical restoration of the footprint. Purpose: To compare 5 different types of suture patterns while maintaining equality in number of anchors. The hypothesis was that the Mason-Allen–crossed cruciform transosseous-equivalent technique is superior to other suture configurations while maintaining equality in suture limbs and anchors. Study Design: Controlled laboratory study. Methods: A total of 25 fresh-frozen cadaveric shoulders were randomized into 5 suture configuration groups: single-row repair with simple stitch technique; single-row repair with modified Mason-Allen technique; double-row Mason-Allen technique; double-row cross-bridge technique; and double-row suture bridge technique. Load and displacement were recorded at 100 Hz until failure. Stiffness and bone mineral density were also measured. Results: There was no significant difference in peak load at failure, stiffness, maximum displacement at failure, or mean bone mineral density among the 5 suture configuration groups (P < .05). Conclusion: According to study results, when choosing a repair technique, other factors such as number of sutures in the repair should be considered to judge the strength of the repair. Clinical Relevance: Previous in vitro studies have shown the double-row rotator cuff repair to be superior to the single-row repair; however, clinical research does not necessarily support this. This study found no difference when comparing 5 different repair methods, supporting research that suggests the number of sutures and not the pattern can affect biomechanical properties. PMID:26665053

Heroic Reliability Improvement in Manned Space Systems

NASA Technical Reports Server (NTRS)

Jones, Harry W.

2017-01-01

System reliability can be significantly improved by a strong continued effort to identify and remove all the causes of actual failures. Newly designed systems often have unexpected high failure rates which can be reduced by successive design improvements until the final operational system has an acceptable failure rate. There are many causes of failures and many ways to remove them. New systems may have poor specifications, design errors, or mistaken operations concepts. Correcting unexpected problems as they occur can produce large early gains in reliability. Improved technology in materials, components, and design approaches can increase reliability. The reliability growth is achieved by repeatedly operating the system until it fails, identifying the failure cause, and fixing the problem. The failure rate reduction that can be obtained depends on the number and the failure rates of the correctable failures. Under the strong assumption that the failure causes can be removed, the decline in overall failure rate can be predicted. If a failure occurs at the rate of lambda per unit time, the expected time before the failure occurs and can be corrected is 1/lambda, the Mean Time Before Failure (MTBF). Finding and fixing a less frequent failure with the rate of lambda/2 per unit time requires twice as long, time of 1/(2 lambda). Cutting the failure rate in half requires doubling the test and redesign time and finding and eliminating the failure causes.Reducing the failure rate significantly requires a heroic reliability improvement effort.

Association Between Use of Long-Acting Nitrates and Outcomes in Heart Failure With Preserved Ejection Fraction.

PubMed

Lim, Shir Lynn; Benson, Lina; Dahlström, Ulf; Lam, Carolyn S P; Lund, Lars H

2017-04-01

Nitrates may be beneficial in heart failure with preserved ejection fraction (HFpEF) by enhancing cGMP signaling and improving hemodynamics, but real-world data on potential efficacy are lacking. We linked the Swedish Heart Failure Registry to national registries with International Classification of Diseases, Tenth Revision comorbidity diagnoses and demographic and socioeconomic data. In HFpEF, defined as left ventricular ejection fraction ≥40%, we derived propensity scores for nitrate use using 52 baseline variables. The association between nitrate use and all-cause mortality and the composite of all-cause mortality or first heart failure hospitalization was assessed in a cohort matched 2:1 untreated to treated based on age and propensity score. In the overall HFpEF cohort (n=19 047; mean [SD] age, 76 [12] years; 46% women), nitrates were used in 17%, and the crude 1-year survival for treated versus untreated patients was 79% (95% confidence interval [CI], 78%-80%) versus 84% (95% CI, 83%-84%) respectively; hazard ratio was 1.48 (95% CI, 1.40-1.56; P <0.001) during a median 755-day follow-up. Matching yielded 2235 treated versus 4470 untreated patients, with 1-year survival of 80% (95% CI, 78%-82%) versus 79% (95% CI, 78%-81%) and hazard ratio of 1.06 (95% CI, 0.98-1.15; P =0.12). Nitrates were associated with worse composite outcome in the matched HFpEF cohort, with 1-year event-free survival of 62% (95% CI, 60%-64%) versus 65% (95% CI, 63%-66%) and hazard ratio of 1.11 (95% CI, 1.04-1.18; P =0.003). These patterns were reproduced in several consistency analyses. In HFpEF, the use of nitrates was not associated with improvements in all-cause mortality or heart failure hospitalization. © 2017 American Heart Association, Inc.

Climate change and the selective signature of the Late Ordovician mass extinction.

PubMed

Finnegan, Seth; Heim, Noel A; Peters, Shanan E; Fischer, Woodward W

2012-05-01

Selectivity patterns provide insights into the causes of ancient extinction events. The Late Ordovician mass extinction was related to Gondwanan glaciation; however, it is still unclear whether elevated extinction rates were attributable to record failure, habitat loss, or climatic cooling. We examined Middle Ordovician-Early Silurian North American fossil occurrences within a spatiotemporally explicit stratigraphic framework that allowed us to quantify rock record effects on a per-taxon basis and assay the interplay of macrostratigraphic and macroecological variables in determining extinction risk. Genera that had large proportions of their observed geographic ranges affected by stratigraphic truncation or environmental shifts at the end of the Katian stage were particularly hard hit. The duration of the subsequent sampling gaps had little effect on extinction risk, suggesting that this extinction pulse cannot be entirely attributed to rock record failure; rather, it was caused, in part, by habitat loss. Extinction risk at this time was also strongly influenced by the maximum paleolatitude at which a genus had previously been sampled, a macroecological trait linked to thermal tolerance. A model trained on the relationship between 16 explanatory variables and extinction patterns during the early Katian interval substantially underestimates the extinction of exclusively tropical taxa during the late Katian interval. These results indicate that glacioeustatic sea-level fall and tropical ocean cooling played important roles in the first pulse of the Late Ordovician mass extinction in Laurentia.

Toll-like receptors-2 and 4 are overexpressed in an experimental model of particle-induced osteolysis.

PubMed

Valladares, Roberto D; Nich, Christophe; Zwingenberger, Stefan; Li, Chenguang; Swank, Katherine R; Gibon, Emmanuel; Rao, Allison J; Yao, Zhenyu; Goodman, Stuart B

2014-09-01

Aseptic loosening secondary to particle-associated periprosthetic osteolysis remains a major cause of failure of total joint replacements (TJR) in the mid- and long term. As sentinels of the innate immune system, macrophages are central to the recognition and initiation of the inflammatory cascade, which results in the activation of bone resorbing osteoclasts. Toll-like receptors (TLRs) are involved in the recognition of pathogen-associated molecular patterns and danger-associated molecular patterns. Experimentally, polymethylmethacrylate and polyethylene (PE) particles have been shown to activate macrophages via the TLR pathway. The specific TLRs involved in PE particle-induced osteolysis remain largely unknown. We hypothesized that TLR-2, -4, and -9 mediated responses play a critical role in the development of PE wear particle-induced osteolysis in the murine calvarium model. To test this hypothesis, we first demonstrated that PE particles caused observable osteolysis, visible by microCT and bone histomorphometry when the particles were applied to the calvarium of C57BL/6 mice. The number of TRAP positive osteoclasts was significantly greater in the PE-treated group when compared to the control group without particles. Finally, using immunohistochemistry, TLR-2 and TLR-4 were highly expressed in PE particle-induced osteolytic lesions, whereas TLR-9 was downregulated. TLR-2 and -4 may represent novel therapeutic targets for prevention of wear particle-induced osteolysis and accompanying TJR failure. © 2013 Wiley Periodicals, Inc.

The immunohistochemical evaluation of selected markers in the left atrium of dogs with end-stage dilated cardiomyopathy and myxomatous mitral valve disease - a preliminary study.

PubMed

Janus, Izabela; Kandefer-Gola, Małgorzata; Ciaputa, Rafał; Noszczyk-Nowak, Agnieszka; Pasławska, Urszula; Tursi, Massimiliano; Nowak, Marcin

2016-01-01

Dilated cardiomyopathy (DCM) and myxomatous mitral valve disease (MMVD) are the most common diseases noted in dogs. Although their pathogenesis varies, both include a significant enlargement of the left atrium. The study was carried out on left atrial specimens obtained from 56 dogs, including those from 34 dogs with clinically diagnosed MMVD, 15 dogs with DCM and 7 dogs without heart disease (control group). Dogs in the MMVD and the DCM groups presented with left atrial enlargement and stage D heart failure. The specimens underwent immunohistochemical examination using desmin, vimentin, periostin and caspase-3 antibodies. There were alterations in the expression of the studied proteins in the study groups compared to the control group. The changes included: irregularity of desmin cross-striation and desmosomes, a higher amount of vimentin-positive cells, a change in the periostin expression pattern from cytoplasmic to extracellular, and a lower expression of caspase-3. The alterations were more pronounced in the DCM group than in the MMVD group. During heart failure, the pattern of desmin, vimentin, periostin and caspase-3 expression alters in the left atrium, regardless of the cause. The changes are more pronounced in dogs with DCM than in dogs with MMVD and similar left atrial enlargement, suggesting that volume overload may not be the only cause of myocardial changes in DCM.

Spacecraft Parachute Recovery System Testing from a Failure Rate Perspective

NASA Technical Reports Server (NTRS)

Stewart, Christine E.

2013-01-01

Spacecraft parachute recovery systems, especially those with a parachute cluster, require testing to identify and reduce failures. This is especially important when the spacecraft in question is human-rated. Due to the recent effort to make spaceflight affordable, the importance of determining a minimum requirement for testing has increased. The number of tests required to achieve a mature design, with a relatively constant failure rate, can be estimated from a review of previous complex spacecraft recovery systems. Examination of the Apollo parachute testing and the Shuttle Solid Rocket Booster recovery chute system operation will clarify at which point in those programs the system reached maturity. This examination will also clarify the risks inherent in not performing a sufficient number of tests prior to operation with humans on-board. When looking at complex parachute systems used in spaceflight landing systems, a pattern begins to emerge regarding the need for a minimum amount of testing required to wring out the failure modes and reduce the failure rate of the parachute system to an acceptable level for human spaceflight. Not only a sufficient number of system level testing, but also the ability to update the design as failure modes are found is required to drive the failure rate of the system down to an acceptable level. In addition, sufficient data and images are necessary to identify incipient failure modes or to identify failure causes when a system failure occurs. In order to demonstrate the need for sufficient system level testing prior to an acceptable failure rate, the Apollo Earth Landing System (ELS) test program and the Shuttle Solid Rocket Booster Recovery System failure history will be examined, as well as some experiences in the Orion Capsule Parachute Assembly System will be noted.

Critical fault patterns determination in fault-tolerant computer systems

NASA Technical Reports Server (NTRS)

Mccluskey, E. J.; Losq, J.

1978-01-01

The method proposed tries to enumerate all the critical fault-patterns (successive occurrences of failures) without analyzing every single possible fault. The conditions for the system to be operating in a given mode can be expressed in terms of the static states. Thus, one can find all the system states that correspond to a given critical mode of operation. The next step consists in analyzing the fault-detection mechanisms, the diagnosis algorithm and the process of switch control. From them, one can find all the possible system configurations that can result from a failure occurrence. Thus, one can list all the characteristics, with respect to detection, diagnosis, and switch control, that failures must have to constitute critical fault-patterns. Such an enumeration of the critical fault-patterns can be directly used to evaluate the overall system tolerance to failures. Present research is focused on how to efficiently make use of these system-level characteristics to enumerate all the failures that verify these characteristics.

Failure modes of Y-TZP abutments with external hex implant-abutment connection determined by fractographic analysis.

PubMed

Basílio, Mariana de Almeida; Delben, Juliana Aparecida; Cesar, Paulo Francisco; Rizkalla, Amin Sami; Santos Junior, Gildo Coelho; Arioli Filho, João Neudenir

2016-07-01

Yttria-stabilized tetragonal zirconia (Y-TZP) was introduced as ceramic implant abutments due to its excellent mechanical properties. However, the damage patterns for Y-TZP abutments are limited in the literature. Fractographic analyses can provide insights as to the failure origin and related mechanisms. The purpose of this study was to analyze fractured Y-TZP abutments to establish fractographic patterns and then possible reasons for failure. Thirty two prefabricated Y-TZP abutments on external hex implants were retrieved from a single-load-to failure test according to the ISO 14801. Fractographic analyses were conducted under polarized-light estereo and scanning electro microscopy. The predominant fracture pattern was abutment fracture at the connecting region. Classic fractographic features such as arrest lines, hackle, and twist hackle established that failure started where Y-TZP abutments were in contact with the retention screw edges. The abutment screw design and the loading point were the reasons for localized stress concentration and fracture patterns. Copyright © 2016 Elsevier Ltd. All rights reserved.

A huge bladder calculus causing acute renal failure.

PubMed

Komeya, Mitsuru; Sahoda, Tamami; Sugiura, Shinpei; Sawada, Takuto; Kitami, Kazuo

2013-02-01

A 81-year-old male was referred to our emergency outpatient unit due to acute renal failure. The level of serum creatinine was 276 μmol/l. A CT scan showed bilateral hydronephroureter, large bladder stone (7 cm × 6 cm × 6 cm) and bladder wall thickness. He was diagnosed as post renal failure due to bilateral hydronephroureter. Large bladder stone is thought to be the cause of bilateral hydronephroureter and renal failure. To improve renal failure, we performed open cystolithotomy and urethral catheterization. Three days after the surgery, the level of serum creatinine decreased to 224 μmol/l. He was discharged from our hospital with uneventful course. Bladder calculus is thought to be a rare cause of renal failure. We summarize the characteristics of bladder calculus causing renal failure. We should keep that long-term pyuria and urinary symptom, and repeated urinary tract infection can cause huge bladder calculus and renal failure in mind.

Comparison of frequencies of left ventricular systolic and diastolic heart failure in Chinese living in Hong Kong.

PubMed

Yip, G W; Ho, P P; Woo, K S; Sanderson, J E

1999-09-01

There is a wide variation (13% to 74%) in the reported prevalence of heart failure associated with normal left ventricular (LV) systolic function (diastolic heart failure). There is no published information on this condition in China. To ascertain the prevalence of diastolic heart failure in this community, 200 consecutive patients with the typical features of congestive heart failure were studied with standard 2-dimensional Doppler echocardiography. A LV ejection fraction (LVEF) >45% was considered normal. The results showed that 12.5% had significant valvular heart disease. Of the remaining 175 patients, 132 had a LVEF >45% (75%). Therefore, 66% of patients with a clinical diagnosis of heart failure had a normal LVEF. Heart failure with normal LV systolic function was more common than systolic heart failure in those >70 years old (65% vs 47%; p = 0.015). Most (57%) had an abnormal relaxation pattern in diastole and 14% had a restrictive filling pattern. In the systolic heart failure group, a restrictive filling pattern was more common (46%). There were no significant differences in the sex distribution, etiology, or prevalence of LV hypertrophy between these 2 heart failure groups. In conclusion, heart failure with a normal LVEF or diastolic heart failure is more common than systolic heart failure in Chinese patients with the symptoms of heart failure. This may be related to older age at presentation and the high prevalence of hypertension in this community.

Bond strength of dental adhesive systems irradiated with ionizing radiation.

PubMed

Dibo da Cruz, Adriana; Goncalves, Luciano de Souza; Rastelli, Alessandra Nara de Souza; Correr-Sobrinho, Lorenco; Bagnato, Vanderlei Salvador; Boscolo, Frab Norberto

2010-04-01

The aim of the present paper was to determine the effect of different types of ionizing radiation on the bond strength of three different dentin adhesive systems. One hundred twenty specimens of 60 human teeth (protocol number: 032/2007) sectioned mesiodistally were divided into 3 groups according to the adhesives systems used: SB (Adper Single Bond Plus), CB (Clearfil SE Bond) and AP (Adper Prompt Self-Etch). The adhesives were applied on dentin and photo-activated using LED (Lec 1000, MMoptics, 1000 mW/cm2). Customized elastomer molds (0.5 mm thickness) with three orifices of 1.2 mm diameter were placed onto the bonding areas and filled with composite resin (Filtek Z-250), which was photo-activated for 20 s. Each group was subdivided into 4 subgroups for application of the different types of ionizing radiation: ultraviolet radiation (UV), diagnostic x-ray radiation (DX), therapeutic x-ray radiation (TX) and without irradiation (control group, CG). Microshear tests were carried out (Instron, model 4411), and afterwards the modes of failure were evaluated by optical and scanning electron microscope and classified using 5 scores: adhesive failure, mixed failures with 3 significance levels, and cohesive failure. The results of the shear bond strength test were submitted to ANOVA with Tukey's test and Dunnett's test, and the data from the failure pattern evaluation were analyzed with the Mann Whitney test (p = 0.05). No change in bond strength of CB and AP was observed after application of the different radiation types, only SB showed increase in bond strength after UV (p = 0.0267) irradiation. The UV also changed the failure patterns of SB (p = 0.0001). The radio-induced changes did not cause degradation of the restorations, which means that they can be exposed to these types of ionizing radiation without weakening the bond strength.

High-Output Heart Failure Caused by Thyrotoxicosis and Beriberi.

PubMed

McCulloch, Brenda

2015-12-01

High-output heart failure is not seen as commonly as low-output heart failure and some of the typical guideline recommendations may not benefit patients with high-output failure. High-output failure is caused by several diseases, including thyrotoxicosis and beriberi, highlighted in this article. Thyrotoxicosis, caused by excessive thyroid hormone production, has profound hemodynamic effects. Wet beriberi, affecting predominately the cardiovascular system, is caused by severe thiamine deficiency, most commonly seen in patients with chronic alcoholism or poor nutrition from other causes. Prompt recognition of these infrequently seen syndromes is essential. This article outlines the medical treatment and nursing care needed to return these patients to a normal state. Copyright © 2015 Elsevier Inc. All rights reserved.

Patterns of technical error among surgical malpractice claims: an analysis of strategies to prevent injury to surgical patients.

PubMed

Regenbogen, Scott E; Greenberg, Caprice C; Studdert, David M; Lipsitz, Stuart R; Zinner, Michael J; Gawande, Atul A

2007-11-01

To identify the most prevalent patterns of technical errors in surgery, and evaluate commonly recommended interventions in light of these patterns. The majority of surgical adverse events involve technical errors, but little is known about the nature and causes of these events. We examined characteristics of technical errors and common contributing factors among closed surgical malpractice claims. Surgeon reviewers analyzed 444 randomly sampled surgical malpractice claims from four liability insurers. Among 258 claims in which injuries due to error were detected, 52% (n = 133) involved technical errors. These technical errors were further analyzed with a structured review instrument designed by qualitative content analysis. Forty-nine percent of the technical errors caused permanent disability; an additional 16% resulted in death. Two-thirds (65%) of the technical errors were linked to manual error, 9% to errors in judgment, and 26% to both manual and judgment error. A minority of technical errors involved advanced procedures requiring special training ("index operations"; 16%), surgeons inexperienced with the task (14%), or poorly supervised residents (9%). The majority involved experienced surgeons (73%), and occurred in routine, rather than index, operations (84%). Patient-related complexities-including emergencies, difficult or unexpected anatomy, and previous surgery-contributed to 61% of technical errors, and technology or systems failures contributed to 21%. Most technical errors occur in routine operations with experienced surgeons, under conditions of increased patient complexity or systems failure. Commonly recommended interventions, including restricting high-complexity operations to experienced surgeons, additional training for inexperienced surgeons, and stricter supervision of trainees, are likely to address only a minority of technical errors. Surgical safety research should instead focus on improving decision-making and performance in routine operations for complex patients and circumstances.

Combined pulmonary involvement in hereditary lysozyme amyloidosis with associated pulmonary sarcoidosis: a case report.

PubMed

McCarthy, Cormac; Deegan, Alexander P; Garvey, John F; McDonnell, Timothy J

2013-12-17

Sarcoidosis is a multisystem inflammatory disorder of unknown cause which can affect any organ system. Autosomal dominant lysozyme amyloidosis is a very rare form of hereditary amyloidosis. The Arg64 variant is extraordinarily rare with each family showing a particular pattern of organ involvement, however while Sicca syndrome, gastrointestinal involvement and renal failure are common, lymph node involvement is very rare. In this case report we describe the first reported case of sarcoidosis in association with hereditary lysozyme amyloidosis.

Payload maintenance cost model for the space telescope

NASA Technical Reports Server (NTRS)

White, W. L.

1980-01-01

An optimum maintenance cost model for the space telescope for a fifteen year mission cycle was developed. Various documents and subsequent updates of failure rates and configurations were made. The reliability of the space telescope for one year, two and one half years, and five years were determined using the failure rates and configurations. The failure rates and configurations were also used in the maintenance simulation computer model which simulate the failure patterns for the fifteen year mission life of the space telescope. Cost algorithms associated with the maintenance options as indicated by the failure patterns were developed and integrated into the model.

Striving for habitual well-being in noninvasive ventilation: a grounded theory study of chronic obstructive pulmonary disease patients with acute respiratory failure.

PubMed

Sørensen, Dorthe; Frederiksen, Kirsten; Groefte, Thorbjoern; Lomborg, Kirsten

2014-06-01

To present a theoretical account of the pattern of behaviour in patients with acute respiratory failure due to chronic obstructive pulmonary disease while undergoing noninvasive ventilation in a hospital setting. Strong evidence supports a positive effect of noninvasive ventilation, but successful treatment remains a challenge. Little attention has been given to patient intolerance to noninvasive ventilation as a cause of treatment failure. A better understanding of the patients' patterns of behaviour during noninvasive ventilation may improve treatment success. A constant comparative classic grounded theory study was performed. Data collection consisted of participant observation during the treatment of 21 patients undergoing noninvasive ventilation, followed by interviews with 11 of the patients after treatment completion. Data were collected from December 2009-January 2012. A substantive theory of striving for habitual well-being was developed. The theory included three phases: initiation, transition and determination. Each phase contained a set of subcategories to indicate the dimensions of and variations in the participants' behaviour. The substantive theory revealed that the patients' behaviour was related to their breathlessness, sensation of being restrained by the mask and head gear, and the side effects of noninvasive ventilation. This inter-relationship should be addressed in the use of noninvasive ventilation for the treatment of patients with chronic obstructive pulmonary disease to achieve treatment success. © 2013 John Wiley & Sons Ltd.

Are Icelandic rock-slope failures paraglacial? Age evaluation of seventeen rock-slope failures in the Skagafjörður area, based on geomorphological stacking, radiocarbon dating and tephrochronology

NASA Astrophysics Data System (ADS)

Mercier, Denis; Coquin, Julien; Feuillet, Thierry; Decaulne, Armelle; Cossart, Etienne; Jónsson, Helgi Pall; Sæmundsson, Þorstein

2017-11-01

In Iceland there are numerous rock-slope failures, especially in the Tertiary basaltic formations of the northern, eastern and northwestern regions. The temporal pattern of rock-slope failures is fundamental for understanding post-glacial events. In the Skagafjörður district, central northern Iceland, 17 rock-slope failures were investigated to determine the age of their occurrence. A geomorphic survey was carried out to identify and characterize landform units, both on the rock-slope failures and in their immediate vicinity. In this coastal area, we used geomorphological stacking which included the relationship between rock-slope failures and raised beaches caused by glacial isostatic rebounds, the chronology of which was established in previous studies. We searched for depressions on the rock-slope failures to then excavate a series of pits and map the stratigraphy. The resulting stratigraphic framework was then validated using (i) radiocarbon dating of wood remains, and (ii) tephrochronology, both of which were complemented by age-depth model calibration. The results confirm that all the rock-slope failures potentially occurred before the Boreal (8 ka), while 94% occurred before the Preboreal (10 ka). They all potentially occurred after the glacial retreat following the maximal ice extent and the Preboreal. More precisely, 11 of them potentially occurred between the Preboreal and the first half of the Holocene. This study demonstrates the relationship between the deglaciation and destabilization of slopes during the paraglacial phase (debuttressing, decompression, glacial isostatic rebound, seismic activity, etc.), which are also controlling factors favouring landsliding, but are difficult to identify for each individual rock-slope failure.

Good Models Gone Bad: Quantifying and Predicting Parameter-Induced Climate Model Simulation Failures

NASA Astrophysics Data System (ADS)

Lucas, D. D.; Klein, R.; Tannahill, J.; Brandon, S.; Covey, C. C.; Domyancic, D.; Ivanova, D. P.

2012-12-01

Simulations using IPCC-class climate models are subject to fail or crash for a variety of reasons. Statistical analysis of the failures can yield useful insights to better understand and improve the models. During the course of uncertainty quantification (UQ) ensemble simulations to assess the effects of ocean model parameter uncertainties on climate simulations, we experienced a series of simulation failures of the Parallel Ocean Program (POP2). About 8.5% of our POP2 runs failed for numerical reasons at certain combinations of parameter values. We apply support vector machine (SVM) classification from the fields of pattern recognition and machine learning to quantify and predict the probability of failure as a function of the values of 18 POP2 parameters. The SVM classifiers readily predict POP2 failures in an independent validation ensemble, and are subsequently used to determine the causes of the failures via a global sensitivity analysis. Four parameters related to ocean mixing and viscosity are identified as the major sources of POP2 failures. Our method can be used to improve the robustness of complex scientific models to parameter perturbations and to better steer UQ ensembles. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was funded by the Uncertainty Quantification Strategic Initiative Laboratory Directed Research and Development Project at LLNL under project tracking code 10-SI-013 (UCRL LLNL-ABS-569112).

Artificial Immune System for Flight Envelope Estimation and Protection

DTIC Science & Technology

2014-12-31

Throttle Failure 103 5.3. Estimation Algorithms for Sensor AC 108 5.3.1. Roll Rate Sensor Bias 108...4.13. Reference Features-Pattern for a Roll Rate Sensor Under Low Severity Failure 93 Figure 4.14. Reference Features-Pattern for a Roll Rate...Average PI for Different ACs 134 Figure 6.9. Roll Response Under High Magnitude Stabilator Failure 135 Figure 6.10. Pitch

Should adolescents with glomerulopathies be treated as children or adults?

PubMed

Requião-Moura, Lúcio R; Veras de S Freitas, Tainá; Franco, Marcello F; Pereira, Aparecido B; Mastroianni-Kirsztajn, Gianna

2008-01-01

Glomerular diseases are an important cause of end-stage renal disease, especially among young adults. However, clinical and epidemiological surveys involving adolescent populations are scarce. To determine the pattern of glomerulopathies (GP) in adolescents submitted to renal biopsy. A retrospective study of patients' records of the Glomerulopathy Section, UNIFESP (Brazil), was performed Among 72 adolescents (12-18 years) with GP, 15.6 +/- 1.5 years, 58.3% females, the most frequent clinical manifestation was nephrotic syndrome (NS, 71%) and focal segmental glomerulosclerosis (FSGS) was the main histological pattern (24%), followed by minimal change disease (MCD, 19.5%). After comparing the main causes of NS in adolescents with those of adults, we found no statistically significant differences in clinical presentation or outcome. Renal failure-free survival of 1 and 5 years for all GP corresponded to 87.9 and 73.6%, respectively (88.5 and 76.3% for NS). NS was the main manifestation; FSGS and MCD were the most common histological diagnoses. Our data suggest the GP and particularly the NS pattern in adolescents is similar to that of adults, pointing to the need for an adaptation in diagnostic and treatment protocols for this age group, a pattern which corresponds more closely to that of adults. Copyright 2008 S. Karger AG, Basel.

Graphical Displays Assist In Analysis Of Failures

NASA Technical Reports Server (NTRS)

Pack, Ginger; Wadsworth, David; Razavipour, Reza

1995-01-01

Failure Environment Analysis Tool (FEAT) computer program enables people to see and better understand effects of failures in system. Uses digraph models to determine what will happen to system if set of failure events occurs and to identify possible causes of selected set of failures. Digraphs or engineering schematics used. Also used in operations to help identify causes of failures after they occur. Written in C language.

Patterns of Failure After Proton Therapy in Medulloblastoma; Linear Energy Transfer Distributions and Relative Biological Effectiveness Associations for Relapses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sethi, Roshan V.; Giantsoudi, Drosoula; Raiford, Michael

2014-03-01

Purpose: The pattern of failure in medulloblastoma patients treated with proton radiation therapy is unknown. For this increasingly used modality, it is important to ensure that outcomes are comparable to those in modern photon series. It has been suggested this pattern may differ from photons because of variations in linear energy transfer (LET) and relative biological effectiveness (RBE). In addition, the use of matching fields for delivery of craniospinal irradiation (CSI) may influence patterns of relapse. Here we report the patterns of failure after the use of protons, compare it to that in the available photon literature, and determine themore » LET and RBE values in areas of recurrence. Methods and Materials: Retrospective review of patients with medulloblastoma treated with proton radiation therapy at Massachusetts General Hospital (MGH) between 2002 and 2011. We documented the locations of first relapse. Discrete failures were contoured on the original planning computed tomography scan. Monte Carlo calculation methods were used to estimate the proton LET distribution. Models were used to estimate RBE values based on the LET distributions. Results: A total of 109 patients were followed for a median of 38.8 months (range, 1.4-119.2 months). Of the patients, 16 experienced relapse. Relapse involved the supratentorial compartment (n=8), spinal compartment (n=11), and posterior fossa (n=5). Eleven failures were isolated to a single compartment; 6 failures in the spine, 4 failures in the supratentorium, and 1 failure in the posterior fossa. The remaining patients had multiple sites of disease. One isolated spinal failure occurred at the spinal junction of 2 fields. None of the 70 patients treated with an involved-field-only boost failed in the posterior fossa outside of the tumor bed. We found no correlation between Monte Carlo-calculated LET distribution and regions of recurrence. Conclusions: The most common site of failure in patients treated with protons for medulloblastoma was outside of the posterior fossa. The most common site for isolated local failure was the spine. We recommend consideration of spinal imaging in follow-up and careful attention to dose distribution in the spinal junction regions. Development of techniques that do not require field matching may be of benefit. We did not identify a direct correlation between lower LET values and recurrence in medulloblastoma patients treated with proton therapy. Patterns of failure do not appear to differ from those in patients treated with photon therapy.« less

Cheyne-Stokes respiration in patients with congestive heart failure: causes and consequences.

PubMed

Lorenzi-Filho, Geraldo; Genta, Pedro R; Figueiredo, Adelaide C; Inoue, Daniel

2005-08-01

Cheyne-Stokes respiration is a form of periodic breathing in which central apneas and hypopneas alternate with periods of hyperventilation, producing a waxing and waning pattern of tidal volume. This review focuses on the causes and consequences of Cheyne-Stokes respiration in patients with congestive heart failure, in whom the prevalence is strikingly high and ranges from 30% to 50%. Several factors have been implicated in the genesis of Cheyne-Stokes respiration, including low cardiac output and recurrent hypoxia. The key pathophysiological mechanism triggering Cheyne-Stokes respiration is hyperventilation and low arterial CO2 (PaCO2) that when below the apneic threshold triggers a central apnea. Hyperventilation is associated with pulmonary congestion, and Cheyne-Stokes respiration is more prone to occur during sleep, when the respiratory system is mainly dependent on chemical control. It is associated with recurrent dips in oxygen saturation and arousals from sleep, with oscillations in blood pressure and heart rate, sympathetic activation and increased risk of ventricular tachycardia. Cheyne-Stokes respiration is an independent marker of poor prognosis and may participate in a vicious cycle, further stressing the failing heart.

Common Cause Failure Modeling

NASA Technical Reports Server (NTRS)

Hark, Frank; Britton, Paul; Ring, Robert; Novack, Steven

2015-01-01

Space Launch System (SLS) Agenda: Objective; Key Definitions; Calculating Common Cause; Examples; Defense against Common Cause; Impact of varied Common Cause Failure (CCF) and abortability; Response Surface for various CCF Beta; Takeaways.

Primary failure of eruption: further characterization of a rare eruption disorder.

PubMed

Frazier-Bowers, Sylvia A; Koehler, Karen E; Ackerman, James L; Proffit, William R

2007-05-01

Posterior open bite has several possible causes, including primary failure of eruption (PFE) that affects all teeth distal to the most mesial involved tooth, mechanical failure of eruption (MFE) (primarily ankylosis) that affects only the involved tooth or teeth, and soft-tissue interferences with eruption (other). Radiographs and other clinical records for 97 cases of failure of posterior eruption submitted for consultation were analyzed to further characterize PFE and distinguish it from MFE. Of the 97 cases, 38 were judged to be clear-cut PFE; 19 were diagnosed as MFE; 32 were classified as indeterminate failure because they were too young to be certain of the distinction between PFE and MFE; and 8 were placed in the "other" category. Two subtypes of PFE were observed. In type 1, eruption failure occurred at or near the same time for all teeth in an affected quadrant. In type 2, a gradient of the time of failure was present, so that some further development of the teeth posterior to the most mesial affected tooth was observed before eruption failure. A family history of eruption problems was noted in 10 of the 38 PFE subjects (26%), and a pedigree analysis was done for 4 families. This was consistent with autosomal dominant transmission. The distinction between PFE and MFE is clinically important because it determines whether all posterior teeth, or only individual affected teeth, will not respond to orthodontic force. Certain diagnosis often requires progress radiographs so that the pattern of eruption of teeth distal to the most mesial affected tooth can be observed.

Shell feature: a new radiomics descriptor for predicting distant failure after radiotherapy in non-small cell lung cancer and cervix cancer

NASA Astrophysics Data System (ADS)

Hao, Hongxia; Zhou, Zhiguo; Li, Shulong; Maquilan, Genevieve; Folkert, Michael R.; Iyengar, Puneeth; Westover, Kenneth D.; Albuquerque, Kevin; Liu, Fang; Choy, Hak; Timmerman, Robert; Yang, Lin; Wang, Jing

2018-05-01

Distant failure is the main cause of human cancer-related mortalities. To develop a model for predicting distant failure in non-small cell lung cancer (NSCLC) and cervix cancer (CC) patients, a shell feature, consisting of outer voxels around the tumor boundary, was constructed using pre-treatment positron emission tomography (PET) images from 48 NSCLC patients received stereotactic body radiation therapy and 52 CC patients underwent external beam radiation therapy and concurrent chemotherapy followed with high-dose-rate intracavitary brachytherapy. The hypothesis behind this feature is that non-invasive and invasive tumors may have different morphologic patterns in the tumor periphery, in turn reflecting the differences in radiological presentations in the PET images. The utility of the shell was evaluated by the support vector machine classifier in comparison with intensity, geometry, gray level co-occurrence matrix-based texture, neighborhood gray tone difference matrix-based texture, and a combination of these four features. The results were assessed in terms of accuracy, sensitivity, specificity, and AUC. Collectively, the shell feature showed better predictive performance than all the other features for distant failure prediction in both NSCLC and CC cohorts.

Factors affecting failure to quit smoking after exposure to pictorial cigarette pack warnings among employees in Thailand.

PubMed

Sujirarat, Dusit; Silpasuwan, Pimpan; Viwatwongkasem, Chukiat; Sirichothiratana, Nithat

2011-07-01

This study was carried out to determine whether health warning pictures(HWP) affect smoking cessation using a structured equation model for intending-to-quit smokers in work places. Data from a 1-year longitudinal followup of attempt-to-quit employees was obtained to determine if pack warnings affect tobacco cessation rates. Stratified simple random sampling, and Structured Equation Modeling (SEM) were employed. Approximately 20% of intending-to-quit smokers were successful. The integrated model, combining internal, interpersonal factors and health warning pictures as external factors, fit the fail to quit pattern of the model. Having a smoking father was the most significant proximate indicator linked with failure to quit. Although HWL pictures were an external factor in the decision to stop smoking, the direct and indirect causes of failure to quit smoking were the influence of the family members. Fathers contributed to the success or failure of smoking cessation in their children by having an influence on the decision making process. Future HWP should include information about factors that stimulate smokers to quit successfully. The role model of a father on quitting is also important.

Cardiovascular Disease and Patterns of Change in Functional Status Over 15 Years: Findings From the Atherosclerosis Risk in Communities (ARIC) Study.

PubMed

Kucharska-Newton, Anna; Griswold, Michael; Yao, Zhihao Howard; Foraker, Randi; Rose, Kathryn; Rosamond, Wayne; Wagenknecht, Lynne; Koton, Silvia; Pompeii, Lisa; Windham, B Gwen

2017-03-01

Cardiovascular disease (CVD) is the leading cause of premature disability, yet few prospective studies have examined functional status (FS) among persons with CVD. Our aim was to examine patterns of change in FS prior to and after hospitalization for nonfatal myocardial infarction, stroke, and heart failure among members of the Atherosclerosis Risk in Communities (ARIC) study cohort. FS was assessed using a modified Rosow-Breslau questionnaire administered during routine annual telephone interviews conducted from 1993 through 2007 among 15 277 ARIC study participants. An FS score was constructed as a summary measure of responses to questions about participants' ability to perform selected tasks of daily living (eg, walking half a mile, climbing stairs). Incidence of CVD was assessed through ARIC surveillance of hospitalized events. Rate of change in FS over time prior to and following a CVD event was examined using generalized estimating equations. A decline in FS was observed on average 2 years prior to a myocardial infarction hospitalization and on average 3 years prior to a stroke or heart failure hospitalization. FS post-myocardial infarction declined relative to pre-event levels but improved to close to pre-myocardial infarction levels within 3 years. Decline in FS following incident heart failure and stroke remained over time. Observed patterns of change in FS did not differ appreciably by race or sex. This study documents that a decline in FS precedes incidence of CVD-related hospitalization by at least 2 years, providing a strong argument for routine preventative assessment of FS among older adults. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

High-Temperature Graphitization Failure of Primary Superheater Tube

NASA Astrophysics Data System (ADS)

Ghosh, D.; Ray, S.; Roy, H.; Mandal, N.; Shukla, A. K.

2015-12-01

Failure of boiler tubes is the main cause of unit outages of the plant, which further affects the reliability, availability and safety of the unit. So failure analysis of boiler tubes is absolutely essential to predict the root cause of the failure and the steps are taken for future remedial action to prevent the failure in near future. This paper investigates the probable cause/causes of failure of the primary superheater tube in a thermal power plant boiler. Visual inspection, dimensional measurement, chemical analysis, metallographic examination and hardness measurement are conducted as the part of the investigative studies. Apart from these tests, mechanical testing and fractographic analysis are also conducted as supplements. Finally, it is concluded that the superheater tube is failed due to graphitization for prolonged exposure of the tube at higher temperature.

Polyethylene wear debris in modular acetabular prostheses.

PubMed

Chen, P C; Mead, E H; Pinto, J G; Colwell, C W

1995-08-01

The longevity of total hip arthroplasty has brought forth the recognition of aseptic loosening of prosthetic components as the leading cause of implant failure. Modularity of implants, although a significant improvement in versatility, may increase debris formation, a recognized cause of implant failure. This study was designed to measure the relative motion, and to assess the polyethylene wear debris production at the interface between the metal acetabular shell and the back side of the polyethylene liner, in modular hip prostheses. Five models from 4 manufacturers with different locking mechanisms and acetabular shell surface treatments were tested under long-term simultaneous sinusoidal and static loading (10(7) cycles at 3 Hz with +/- 2.5 Nmeter and 220 N static load). Results showed that there were marked differences in the security of the acetabular shell and polyethylene liner locking mechanism, wear pattern, damage sites, and amount of polyethylene debris on the acetabular shell and polyethylene liner surfaces. The range of polyethylene liner motion observed among the 5 models during 1 cycle of testing varied from an average of 0.96 degrees to movement too small to be detected by the test machines. Image and scanning electron microscopy analysis showed different wear patterns and a wide range in the average polyethylene liner surface wear area (0.26 cm2-4.61 cm2). In general, a stable locking mechanism and a smooth acetabular shell surface are essential in minimizing polyethylene liner wear and polyethylene debris production.

Comparative study of unilateral versus bilateral inferior oblique recession/anteriorization in unilateral inferior oblique overaction.

PubMed

Mostafa, Attiat M; Kassem, Rehab R

2018-05-01

To compare the effect of, and the rate of subsequent development of iatrogenic antielevation syndrome after, unilateral versus bilateral inferior oblique graded recession-anteriorization to treat unilateral inferior oblique overaction. Thirty-four patients with unilateral inferior oblique overaction were included in a randomized prospective study. Patients were equally divided into 2 groups. Group UNI underwent unilateral, group BI bilateral, inferior oblique graded recession-anteriorization. A successful outcome was defined as orthotropia, or within 2 ∆ of a residual hypertropia, in the absence of signs of antielevation syndrome, residual inferior oblique overaction, V-pattern, dissociated vertical deviation, or ocular torticollis. A successful outcome was achieved in 11 (64.7%) and 13 (76.5%) patients in groups UNI and BI, respectively (p = 0.452). Antielevation syndrome was diagnosed as the cause of surgical failure in 6 (35.3%) and 2 (11.8%) patients, in groups UNI and BI, respectively (p = 0.106). The cause of surgical failure in the other 2 patients in group BI was due to persistence of ocular torticollis and hypertropia in a patient with superior oblique palsy and a residual V-pattern and hypertropia in the other patient. The differences between unilateral and bilateral inferior oblique graded recession-anteriorization are insignificant. Unilateral surgery has a higher tendency for the subsequent development of antielevation syndrome. Bilateral surgery may still become complicated by antielevation syndrome, although at a lower rate. In addition, bilateral surgery had a higher rate of undercorrection. Further studies on a larger sample are encouraged.

A Survey of Logic Formalisms to Support Mishap Analysis

NASA Technical Reports Server (NTRS)

Johnson, Chris; Holloway, C. M.

2003-01-01

Mishap investigations provide important information about adverse events and near miss incidents. They are intended to help avoid any recurrence of previous failures. Over time, they can also yield statistical information about incident frequencies that helps to detect patterns of failure and can validate risk assessments. However, the increasing complexity of many safety critical systems is posing new challenges for mishap analysis. Similarly, the recognition that many failures have complex, systemic causes has helped to widen the scope of many mishap investigations. These two factors have combined to pose new challenges for the analysis of adverse events. A new generation of formal and semi-formal techniques have been proposed to help investigators address these problems. We introduce the term mishap logics to collectively describe these notations that might be applied to support the analysis of mishaps. The proponents of these notations have argued that they can be used to formally prove that certain events created the necessary and sufficient causes for a mishap to occur. These proofs can be used to reduce the bias that is often perceived to effect the interpretation of adverse events. Others have argued that one cannot use logic formalisms to prove causes in the same way that one might prove propositions or theorems. Such mechanisms cannot accurately capture the wealth of inductive, deductive and statistical forms of inference that investigators must use in their analysis of adverse events. This paper provides an overview of these mishap logics. It also identifies several additional classes of logic that might also be used to support mishap analysis.

A Competing Risk Model of First Failure Site after Definitive Chemoradiation Therapy for Locally Advanced Non-Small Cell Lung Cancer.

PubMed

Nygård, Lotte; Vogelius, Ivan R; Fischer, Barbara M; Kjær, Andreas; Langer, Seppo W; Aznar, Marianne C; Persson, Gitte F; Bentzen, Søren M

2018-04-01

The aim of the study was to build a model of first failure site- and lesion-specific failure probability after definitive chemoradiotherapy for inoperable NSCLC. We retrospectively analyzed 251 patients receiving definitive chemoradiotherapy for NSCLC at a single institution between 2009 and 2015. All patients were scanned by fludeoxyglucose positron emission tomography/computed tomography for radiotherapy planning. Clinical patient data and fludeoxyglucose positron emission tomography standardized uptake values from primary tumor and nodal lesions were analyzed by using multivariate cause-specific Cox regression. In patients experiencing locoregional failure, multivariable logistic regression was applied to assess risk of each lesion being the first site of failure. The two models were used in combination to predict probability of lesion failure accounting for competing events. Adenocarcinoma had a lower hazard ratio (HR) of locoregional failure than squamous cell carcinoma (HR = 0.45, 95% confidence interval [CI]: 0.26-0.76, p = 0.003). Distant failures were more common in the adenocarcinoma group (HR = 2.21, 95% CI: 1.41-3.48, p < 0.001). Multivariable logistic regression of individual lesions at the time of first failure showed that primary tumors were more likely to fail than lymph nodes (OR = 12.8, 95% CI: 5.10-32.17, p < 0.001). Increasing peak standardized uptake value was significantly associated with lesion failure (OR = 1.26 per unit increase, 95% CI: 1.12-1.40, p < 0.001). The electronic model is available at http://bit.ly/LungModelFDG. We developed a failure site-specific competing risk model based on patient- and lesion-level characteristics. Failure patterns differed between adenocarcinoma and squamous cell carcinoma, illustrating the limitation of aggregating them into NSCLC. Failure site-specific models add complementary information to conventional prognostic models. Copyright © 2018 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Detonation Failure Thickness Measurement in AN Annular Geometry

NASA Astrophysics Data System (ADS)

Mack, D. B.; Petel, O. E.; Higgins, A. J.

2007-12-01

The failure thickness of neat nitromethane in aluminum confinement was measured using a novel experimental technique. The thickness was approximated in an annular geometry by the gap between a concentric aluminum tube and rod. This technique was motivated by the desire to have a periodic boundary condition in the direction orthogonal to the annulus thickness, rather than a free surface occurring in typical rectangular geometry experiments. This results in a two-dimensional charge analogous to previous failure thickness setups but with infinite effective width (i.e. infinite aspect ratio). Detonation propagation or failure was determined by the observation of failure patterns engraved on the aluminum rod by the passing detonation. Analysis of these engraved patterns provides a statistical measurement of the spatial density of failure waves. Failure was observed as far as 180 thicknesses downstream. The failure thickness was measured to be 1.45 mm±0.15 mm.

16 CFR 1207.5 - Design.

Code of Federal Regulations, 2014 CFR

2014-01-01

... pool slide shall be such that no structural failures of any component part shall cause failures of any... such fasteners shall not cause a failure of the tread under the ladder loading conditions specified in... without failure or permanent deformation. (d) Handrails. Swimming pool slide ladders shall be equipped...

16 CFR 1207.5 - Design.

Code of Federal Regulations, 2012 CFR

2012-01-01

... pool slide shall be such that no structural failures of any component part shall cause failures of any... such fasteners shall not cause a failure of the tread under the ladder loading conditions specified in... without failure or permanent deformation. (d) Handrails. Swimming pool slide ladders shall be equipped...

Fatigue failure of metal components as a factor in civil aircraft accidents

NASA Technical Reports Server (NTRS)

Holshouser, W. L.; Mayner, R. D.

1972-01-01

A review of records maintained by the National Transportation Safety Board showed that 16,054 civil aviation accidents occurred in the United States during the 3-year period ending December 31, 1969. Material failure was an important factor in the cause of 942 of these accidents. Fatigue was identified as the mode of the material failures associated with the cause of 155 accidents and in many other accidents the records indicated that fatigue failures might have been involved. There were 27 fatal accidents and 157 fatalities in accidents in which fatigue failures of metal components were definitely identified. Fatigue failures associated with accidents occurred most frequently in landing-gear components, followed in order by powerplant, propeller, and structural components in fixed-wing aircraft and tail-rotor and main-rotor components in rotorcraft. In a study of 230 laboratory reports on failed components associated with the cause of accidents, fatigue was identified as the mode of failure in more than 60 percent of the failed components. The most frequently identified cause of fatigue, as well as most other types of material failures, was improper maintenance (including inadequate inspection). Fabrication defects, design deficiencies, defective material, and abnormal service damage also caused many fatigue failures. Four case histories of major accidents are included in the paper as illustrations of some of the factors invovled in fatigue failures of aircraft components.

Effects of traffic generation patterns on the robustness of complex networks

NASA Astrophysics Data System (ADS)

Wu, Jiajing; Zeng, Junwen; Chen, Zhenhao; Tse, Chi K.; Chen, Bokui

2018-02-01

Cascading failures in communication networks with heterogeneous node functions are studied in this paper. In such networks, the traffic dynamics are highly dependent on the traffic generation patterns which are in turn determined by the locations of the hosts. The data-packet traffic model is applied to Barabási-Albert scale-free networks to study the cascading failures in such networks and to explore the effects of traffic generation patterns on network robustness. It is found that placing the hosts at high-degree nodes in a network can make the network more robust against both intentional attacks and random failures. It is also shown that the traffic generation pattern plays an important role in network design.

Recent advances in the epidemiology, pathogenesis and prognosis of acute heart failure and cardiomyopathy in Africa.

PubMed

Sliwa, Karen; Mayosi, Bongani M

2013-09-01

This review addresses recent advances in the epidemiology, pathogenesis and prognosis of acute heart failure and cardiomyopathy based on research conducted in Africa. We searched Medline/PubMed for publications on acute decompensated heart failure and cardiomyopathy in Africa for the past 5 years (ie, 1 January 2008 to 31 December 2012). This was supplemented with personal communications with colleagues from Africa working in the field. A large prospective registry has shown that acute decompensated heart failure is caused by hypertension, cardiomyopathy and rheumatic heart disease in 90% of cases, a pattern that is in contrast with the dominance of coronary artery disease in North America and Europe. Furthermore, acute heart failure is a disease of the young with a mean age of 52 years, occurs equally in men and women, and is associated with high mortality at 6 months (∼18%), which is, however, similar to that observed in non-African heart failure registries, suggesting that heart failure has a dire prognosis globally, regardless of aetiology. The molecular genetics of dilated cardiomyopathy, hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy in Africans is consistent with observations elsewhere in the world; the unique founder effects in the Afrikaner provide an opportunity for the study of genotype-phenotype correlations in large numbers of individuals with cardiomyopathy due to the same mutation. Advances in the understanding of the molecular mechanisms of peripartum cardiomyopathy have led to promising clinical trials of bromocriptine in the treatment of peripartum heart failure. The key challenges of management of heart failure are the urgent need to increase the use of proven treatments by physicians, and the control of hypertension in primary care and at the population level.

Risk Analysis and Prediction of Floor Failure Mechanisms at Longwall Face in Parvadeh-I Coal Mine using Rock Engineering System (RES)

NASA Astrophysics Data System (ADS)

Aghababaei, Sajjad; Saeedi, Gholamreza; Jalalifar, Hossein

2016-05-01

The floor failure at longwall face decreases productivity and safety, increases operation costs, and causes other serious problems. In Parvadeh-I coal mine, the timber is used to prevent the puncture of powered support base into the floor. In this paper, a rock engineering system (RES)-based model is presented to evaluate the risk of floor failure mechanisms at the longwall face of E 2 and W 1 panels. The presented model is used to determine the most probable floor failure mechanism, effective factors, damaged regions and remedial actions. From the analyzed results, it is found that soft floor failure is dominant in the floor failure mechanism at Parvadeh-I coal mine. The average of vulnerability index (VI) for soft, buckling and compressive floor failure mechanisms was estimated equal to 52, 43 and 30 for both panels, respectively. By determining the critical VI for soft floor failure mechanism equal to 54, the percentage of regions with VIs beyond the critical VI in E 2 and W 1 panels is equal to 65.5 and 30, respectively. The percentage of damaged regions showed that the excess amount of used timber to prevent the puncture of weak floor below the powered support base is equal to 4,180,739 kg. RES outputs and analyzed results showed that setting and yielding load of powered supports, length of face, existent water at face, geometry of powered supports, changing the cutting pattern at longwall face and limiting the panels to damaged regions with supercritical VIs could be considered to control the soft floor failure in this mine. The results of this research could be used as a useful tool to identify the damaged regions prior to mining operation at longwall panel for the same conditions.

Analysis of Emergency Diesel Generators Failure Incidents in Nuclear Power Plants

NASA Astrophysics Data System (ADS)

Hunt, Ronderio LaDavis

In early years of operation, emergency diesel generators have had a minimal rate of demand failures. Emergency diesel generators are designed to operate as a backup when the main source of electricity has been disrupted. As of late, EDGs (emergency diesel generators) have been failing at NPPs (nuclear power plants) around the United States causing either station blackouts or loss of onsite and offsite power. These failures occurred from a specific type called demand failures. This thesis evaluated the current problem that raised concern in the nuclear industry which was averaging 1 EDG demand failure/year in 1997 to having an excessive event of 4 EDG demand failure year which occurred in 2011. To determine the next occurrence of the extreme event and possible cause to an event of such happening, two analyses were conducted, the statistical and root cause analysis. Considering the statistical analysis in which an extreme event probability approach was applied to determine the next occurrence year of an excessive event as well as, the probability of that excessive event occurring. Using the root cause analysis in which the potential causes of the excessive event occurred by evaluating, the EDG manufacturers, aging, policy changes/ maintenance practices and failure components. The root cause analysis investigated the correlation between demand failure data and historical data. Final results from the statistical analysis showed expectations of an excessive event occurring in a fixed range of probability and a wider range of probability from the extreme event probability approach. The root-cause analysis of the demand failure data followed historical statistics for the EDG manufacturer, aging and policy changes/ maintenance practices but, indicated a possible cause regarding the excessive event with the failure components. Conclusions showed the next excessive demand failure year, prediction of the probability and the next occurrence year of such failures, with an acceptable confidence level, was difficult but, it was likely that this type of failure will not be a 100 year event. It was noticeable to see that the majority of the EDG demand failures occurred within the main components as of 2005. The overall analysis of this study provided from percentages, indicated that it would be appropriate to make the statement that the excessive event was caused by the overall age (wear and tear) of the Emergency Diesel Generators in Nuclear Power Plants. Future Work will be to better determine the return period of the excessive event once the occurrence has happened for a second time by implementing the extreme event probability approach.

Behavioral ecology of black-legged kittiwakes during chick rearing in a failing colony

USGS Publications Warehouse

Roberts, Bay D.; Hatch, Scott A.

1993-01-01

Compared with their Atlantic counterparts, Black-legged Kittiwakes (Rissa tridactyla) in North Pacific colonies are notably unproductive. A large colony on Middleton Island, Alaska, has in most years since 1981 seen complete breeding failure and the population has declined by half. We compared parent-offspring behaviors in this colony during two years that differed in overall breeding success. Potential indicators of food stress included parental attendance at the nest, foraging trip lengths, chick feeding and begging rates, and sibling aggression. Whereas chick feeding and begging rates were strongly correlated with overall breeding performance, patterns of time allocation by adults (nest attendance and foraging trips) were not. Contrasts between years and comparisons with data from other colonies in and outside Alaska point to food shortage as the likely cause of recurrent breeding failure on Middleton.

Failure Patterns in Patients with Esophageal Cancer Treated with Definitive Chemoradiation

PubMed Central

Welsh, James; Settle, Stephen H.; Amini, Arya; Xiao, Lianchun; Suzuki, Akihiro; Hayashi, Yuki; Hofstetter, Wayne; Komaki, Ritsuko; Liao, Zhongxing; Ajani, Jaffer A.

2012-01-01

Purpose Local failure after definitive chemoradiation therapy for unresectable esophageal cancer remains problematic. Little is known about the failure pattern based on modern day radiation treatment volumes. We hypothesized that most local failures would be within the gross tumor volume (GTV), where the bulk of the tumor burden resides. Methods and Materials We reviewed treatment volumes for 239 patients who underwent definitive chemoradiation therapy and compared this information with failure patterns on follow-up positron emission (PET). Failures were categorized as within the GTV, the larger clinical target volume (CTV, which encompasses microscopic disease), or the still larger planning target volume (PTV, which encompasses setup variability) or outside the radiation field. Results At a median follow-up time of 52.6 months (95% CI: 46.1 – 56.7 months), 119 patients (50%) had experienced local failure, 114 (48%) had distant failure, and 74 (31%) had no evidence of failure. Of all local failures, 107 (90%) were in the GTV, 27 (23%) in the CTV; and 14 (12%) in the PTV. In multivariate analysis, GTV failure was associated with tumor status (T3/T4 vs. T1/T2: OR=6.35, p value =0.002), change in standardized uptake value on PET before and after treatment (decrease >52%: OR=0.368, p value = 0.003) and tumor length (>8 cm: 4.08, p value = 0.009). Conclusions Most local failures after definitive chemoradiation for unresectable esophageal cancer occur in the GTV. Future therapeutic strategies should focus on enhancing local control. PMID:22565611

New and Evolving Concepts Regarding the Prognosis and Treatment of Cardiac Amyloidosis.

PubMed

Perlini, Stefano; Mussinelli, Roberta; Salinaro, Francesco

2016-12-01

Systemic amyloidoses are rare and proteiform diseases, caused by extracellular accumulation of insoluble misfolded fibrillar proteins. Prognosis is dictated by cardiac involvement, which is especially frequent in light chain (AL) and in transthyretin variants (ATTR, both mutated, (ATTRm), and wild-type, (ATTRwt)). Recently, ATTRwt has emerged as a potentially relevant cause of a heart failure with preserved ejection fraction (HFpEF). Cardiac amyloidosis is an archetypal example of restrictive cardiomyopathy, with signs and symptoms of global heart failure and diastolic dysfunction. Independent of the aetiology, cardiac amyloidosis is associated with left ventricular concentric "hypertrophy" (i.e. increased wall thickness), preserved (or mildly depressed) ejection fraction, reduced midwall fractional shortening and global longitudinal function, as well as evident diastolic dysfunction, up to an overly restrictive pattern of the left ventricular filling. Cardiac biomarkers such as troponins and natriuretic peptides are very robust and widely accepted diagnostic as well as prognostic tools. Owing to its dismal prognosis, accurate and early diagnosis is mandatory and potentially life-saving. Although pathogenesis is still not completely understood, direct cardiomyocyte toxicity of the amyloidogenic precursor proteins and/or oligomer aggregates adds on tissue architecture disruption caused by amyloid deposition. The clarification of mechanisms of cardiac damage is offering new potential therapeutic targets, and several treatment options with a relevant impact on prognosis are now available.

Loss of MeCP2 Causes Urological Dysfunction and Contributes to Death by Kidney Failure in Mouse Models of Rett Syndrome.

PubMed

Ward, Christopher S; Huang, Teng-Wei; Herrera, José A; Samaco, Rodney C; Pitcher, Meagan R; Herron, Alan; Skinner, Steven A; Kaufmann, Walter E; Glaze, Daniel G; Percy, Alan K; Neul, Jeffrey L

2016-01-01

Rett Syndrome (RTT) is a neurodevelopmental disorder characterized by loss of acquired skills during development, autonomic dysfunction, and an increased risk for premature lethality. Clinical experience identified a subset of individuals with RTT that present with urological dysfunction including individuals with frequent urinary tract infections, kidney stones, and urine retention requiring frequent catheterization for bladder voiding. To determine if urologic dysfunction is a feature of RTT, we queried the Rett Syndrome Natural History Study, a repository of clinical data from over 1000 individuals with RTT and found multiple instances of urological dysfunction. We then evaluated urological function in a mouse model of RTT and found an abnormal pattern of micturition. Both male and female mice possessing Mecp2 mutations show a decrease in urine output per micturition event. Furthermore, we identified signs of kidney failure secondary to urethral obstruction. Although genetic strain background significantly affects both survival and penetrance of the urethral obstruction phenotype, survival and penetrance of urethral obstruction do not directly correlate. We have identified an additional phenotype caused by loss of MeCP2, urological dysfunction. Furthermore, we urge caution in the interpretation of survival data as an endpoint in preclinical studies, especially where causes of mortality are poorly characterized.

Loss of MeCP2 Causes Urological Dysfunction and Contributes to Death by Kidney Failure in Mouse Models of Rett Syndrome

PubMed Central

Ward, Christopher S.; Huang, Teng-Wei; Herrera, José A.; Samaco, Rodney C.; Pitcher, Meagan R.; Herron, Alan; Skinner, Steven A.; Kaufmann, Walter E.; Glaze, Daniel G.; Percy, Alan K.; Neul, Jeffrey L.

2016-01-01

Rett Syndrome (RTT) is a neurodevelopmental disorder characterized by loss of acquired skills during development, autonomic dysfunction, and an increased risk for premature lethality. Clinical experience identified a subset of individuals with RTT that present with urological dysfunction including individuals with frequent urinary tract infections, kidney stones, and urine retention requiring frequent catheterization for bladder voiding. To determine if urologic dysfunction is a feature of RTT, we queried the Rett Syndrome Natural History Study, a repository of clinical data from over 1000 individuals with RTT and found multiple instances of urological dysfunction. We then evaluated urological function in a mouse model of RTT and found an abnormal pattern of micturition. Both male and female mice possessing Mecp2 mutations show a decrease in urine output per micturition event. Furthermore, we identified signs of kidney failure secondary to urethral obstruction. Although genetic strain background significantly affects both survival and penetrance of the urethral obstruction phenotype, survival and penetrance of urethral obstruction do not directly correlate. We have identified an additional phenotype caused by loss of MeCP2, urological dysfunction. Furthermore, we urge caution in the interpretation of survival data as an endpoint in preclinical studies, especially where causes of mortality are poorly characterized. PMID:27828991

Program Helps In Analysis Of Failures

NASA Technical Reports Server (NTRS)

Stevenson, R. W.; Austin, M. E.; Miller, J. G.

1993-01-01

Failure Environment Analysis Tool (FEAT) computer program developed to enable people to see and better understand effects of failures in system. User selects failures from either engineering schematic diagrams or digraph-model graphics, and effects or potential causes of failures highlighted in color on same schematic-diagram or digraph representation. Uses digraph models to answer two questions: What will happen to system if set of failure events occurs? and What are possible causes of set of selected failures? Helps design reviewers understand exactly what redundancies built into system and where there is need to protect weak parts of system or remove them by redesign. Program also useful in operations, where it helps identify causes of failure after they occur. FEAT reduces costs of evaluation of designs, training, and learning how failures propagate through system. Written using Macintosh Programmers Workshop C v3.1. Can be linked with CLIPS 5.0 (MSC-21927, available from COSMIC).

Common-Cause Failure Treatment in Event Assessment: Basis for a Proposed New Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dana Kelly; Song-Hua Shen; Gary DeMoss

2010-06-01

Event assessment is an application of probabilistic risk assessment in which observed equipment failures and outages are mapped into the risk model to obtain a numerical estimate of the event’s risk significance. In this paper, we focus on retrospective assessments to estimate the risk significance of degraded conditions such as equipment failure accompanied by a deficiency in a process such as maintenance practices. In modeling such events, the basic events in the risk model that are associated with observed failures and other off-normal situations are typically configured to be failed, while those associated with observed successes and unchallenged components aremore » assumed capable of failing, typically with their baseline probabilities. This is referred to as the failure memory approach to event assessment. The conditioning of common-cause failure probabilities for the common cause component group associated with the observed component failure is particularly important, as it is insufficient to simply leave these probabilities at their baseline values, and doing so may result in a significant underestimate of risk significance for the event. Past work in this area has focused on the mathematics of the adjustment. In this paper, we review the Basic Parameter Model for common-cause failure, which underlies most current risk modelling, discuss the limitations of this model with respect to event assessment, and introduce a proposed new framework for common-cause failure, which uses a Bayesian network to model underlying causes of failure, and which has the potential to overcome the limitations of the Basic Parameter Model with respect to event assessment.« less

Injury pattern as an indication of seat belt failure in ejected vehicle occupants.

PubMed

Freeman, Michael D; Eriksson, Anders; Leith, Wendy

2014-09-01

Prior authors have suggested that when occupant ejection occurs in association with a seat belt failure, entanglement of the outboard upper extremity (OUE) with the retracting shoulder belt will invariably occur, leaving injury pattern evidence of belt use. In the present investigation, the authors assessed this theory using data accessed from the NASS-CDS for ejected front seat occupants of passenger vehicles. Logistic regression models were used to assess the associations between seat belt failure status and injuries. Injury types associated with seat belt failure were significant OUE and head injuries (OR = 3.87, [95% CI 1.2, 13.0] and 3.1, [95% CI 1.0, 9.7], respectively). The two injury types were found to be a predictor of seat belt use and subsequent failure only if combined with a high (≥0.8) precrash probability of belt use. The injury pattern associated with a seat belt failure-related ejection has limited use in the forensic investigation of crash-related ejections. © 2014 American Academy of Forensic Sciences.

Adult and paediatric mortality patterns in a referral hospital in Liberia 1 year after the end of the war.

PubMed

Huerga, Helena; Vasset, Brigitte; Prados, Elisa

2009-05-01

The aim of this study was to describe and analyse hospital mortality patterns after the Liberian war. Data were collected retrospectively from January to July 2005 in a referral hospital in Monrovia, Liberia. The overall fatality rate was 17.2% (438/2543) of medical admissions. One-third of deaths occurred in the first 24h. The adult fatality rate was 23.3% (241/1034). Non-infectious diseases accounted for 56% of the adult deaths. The main causes of death were meningitis (16%), stroke (14%) and heart failure (10%). Associated fatality rates were 48%, 54% and 31% respectively. The paediatric fatality rate was 13.1% (197/1509). Infectious diseases caused 66% of paediatric deaths. In infants <1 month old, the fatality rate was 18% and main causes of death were neonatal sepsis (47%), respiratory distress (24%) and prematurity (18%). The main causes of death in infants > or =1 month old were respiratory infections (27%), malaria (23%) and severe malnutrition (16%). Associated fatality rates were 12%, 10% and 19%. Fatality rates were similar to those found in other sub-Saharan countries without a previous conflict. Early deaths could decrease through recognition and early referral of severe cases from health centres to the hospital and through assessment and priority treatment of these patients at arrival.

Precise design-based defect characterization and root cause analysis

NASA Astrophysics Data System (ADS)

Xie, Qian; Venkatachalam, Panneerselvam; Lee, Julie; Chen, Zhijin; Zafar, Khurram

2017-03-01

As semiconductor manufacturing continues its march towards more advanced technology nodes, it becomes increasingly important to identify and characterize design weak points, which is typically done using a combination of inline inspection data and the physical layout (or design). However, the employed methodologies have been somewhat imprecise, relying greatly on statistical techniques to signal excursions. For example, defect location error that is inherent to inspection tools prevents them from reporting the true locations of defects. Therefore, common operations such as background-based binning that are designed to identify frequently failing patterns cannot reliably identify specific weak patterns. They can only identify an approximate set of possible weak patterns, but within these sets there are many perfectly good patterns. Additionally, characterizing the failure rate of a known weak pattern based on inline inspection data also has a lot of fuzziness due to coordinate uncertainty. SEM (Scanning Electron Microscope) Review attempts to come to the rescue by capturing high resolution images of the regions surrounding the reported defect locations, but SEM images are reviewed by human operators and the weak patterns revealed in those images must be manually identified and classified. Compounding the problem is the fact that a single Review SEM image may contain multiple defective patterns and several of those patterns might not appear defective to the human eye. In this paper we describe a significantly improved methodology that brings advanced computer image processing and design-overlay techniques to better address the challenges posed by today's leading technology nodes. Specifically, new software techniques allow the computer to analyze Review SEM images in detail, to overlay those images with reference design to detect every defect that might be present in all regions of interest within the overlaid reference design (including several classes of defects that human operators will typically miss), to obtain the exact defect location on design, to compare all defective patterns thus detected against a library of known patterns, and to classify all defective patterns as either new or known. By applying the computer to these tasks, we automate the entire process from defective pattern identification to pattern classification with high precision, and we perform this operation en masse during R & D, ramp, and volume production. By adopting the methodology, whenever a specific weak pattern is identified, we are able to run a series of characterization operations to ultimately arrive at the root cause. These characterization operations can include (a) searching all pre-existing Review SEM images for the presence of the specific weak pattern to determine whether there is any spatial (within die or within wafer) or temporal (within any particular date range, before or after a mask revision, etc.) correlation and (b) understanding the failure rate of the specific weak pattern to prioritize the urgency of the problem, (c) comparing the weak pattern against an OPC (Optical Procimity Correction) Verification report or a PWQ (Process Window Qualification)/FEM (Focus Exposure Matrix) result to assess the likelihood of it being a litho-sensitive pattern, etc. After resolving the specific weak pattern, we will categorize it as known pattern, and the engineer will move forward with discovering new weak patterns.

Interaction between regional and magma-induced stresses and their impact on volcano-tectonic seismicity

NASA Astrophysics Data System (ADS)

Vargas-Bracamontes, D. M.; Neuberg, J. W.

2012-10-01

Recent seismological observations have reported volcano-tectonic (VT) earthquakes with fault-plane solutions exhibiting a change of ~ 90° in their pressure axes relative to the regional stress field. Interestingly, they are recorded mainly during periods preceding eruptive activity and coexisting with those VTs showing a regional trend. This study explains the occurrence of such trends in VT seismicity and discusses the possible patterns of earthquake locations related to the interaction of regional and magma-induced stresses caused by pressurization or depressurization of magmatic sources. Our analysis shows that in the presence of a dominant regional stress field, faulting will occur on faults whose associated slip direction is close to or in agreement with the background regional stress. Failure on faults with an opposite slip direction is unlikely to occur. As magma pressure starts counter-acting the regional stresses, the likelihood of faults to slip in either a regional or opposite sense of slip relative to regional maximum compression increases, allowing the co-existence of possible failure with both slip tendencies, however the spatial distribution of possible faulting differs. As the pressure is progressively increased, the stress patterns gradually approach those corresponding to the absence of a regional stress field. The presented modeling results have implications for volcanic monitoring routines aiming to detect changes in stress patterns. They will ultimately help to improve the correct interpretation of volcano-tectonic seismicity.

Immunity-Based Aircraft Fault Detection System

NASA Technical Reports Server (NTRS)

Dasgupta, D.; KrishnaKumar, K.; Wong, D.; Berry, M.

2004-01-01

In the study reported in this paper, we have developed and applied an Artificial Immune System (AIS) algorithm for aircraft fault detection, as an extension to a previous work on intelligent flight control (IFC). Though the prior studies had established the benefits of IFC, one area of weakness that needed to be strengthened was the control dead band induced by commanding a failed surface. Since the IFC approach uses fault accommodation with no detection, the dead band, although it reduces over time due to learning, is present and causes degradation in handling qualities. If the failure can be identified, this dead band can be further A ed to ensure rapid fault accommodation and better handling qualities. The paper describes the application of an immunity-based approach that can detect a broad spectrum of known and unforeseen failures. The approach incorporates the knowledge of the normal operational behavior of the aircraft from sensory data, and probabilistically generates a set of pattern detectors that can detect any abnormalities (including faults) in the behavior pattern indicating unsafe in-flight operation. We developed a tool called MILD (Multi-level Immune Learning Detection) based on a real-valued negative selection algorithm that can generate a small number of specialized detectors (as signatures of known failure conditions) and a larger set of generalized detectors for unknown (or possible) fault conditions. Once the fault is detected and identified, an adaptive control system would use this detection information to stabilize the aircraft by utilizing available resources (control surfaces). We experimented with data sets collected under normal and various simulated failure conditions using a piloted motion-base simulation facility. The reported results are from a collection of test cases that reflect the performance of the proposed immunity-based fault detection algorithm.

Virological patterns of HCV patients with failure to interferon-free regimens.

PubMed

Starace, Mario; Minichini, Carmine; De Pascalis, Stefania; Macera, Margherita; Occhiello, Laura; Messina, Vincenzo; Sangiovanni, Vincenzo; Adinolfi, Luigi E; Claar, Ernesto; Precone, Davide; Stornaiuolo, Gianfranca; Stanzione, Maria; Ascione, Tiziana; Caroprese, Mara; Zampino, Rosa; Parrilli, Gianpaolo; Gentile, Ivan; Brancaccio, Giuseppina; Iovinella, Vincenzo; Martini, Salvatore; Masarone, Mario; Fontanella, Luca; Masiello, Addolorata; Sagnelli, Evangelista; Punzi, Rodolfo; Salomone Megna, Angelo; Santoro, Renato; Gaeta, Giovanni B; Coppola, Nicola

2018-05-01

The study characterized the virological patterns and the resistance-associated substitutions (RASs) in patients with failure to IFN-free regimens enrolled in the real-life setting. All 87 consecutive HCV patients with failed IFN-free regimens, observed at the laboratory of the University of Campania, were enrolled. All patients had been treated with DAA regimens according to the HCV genotype, international guidelines, and local availability. Sanger sequencing of NS3, NS5A, and NS5B regions was performed at failure by home-made protocols. Of the 87 patients enrolled, 13 (14.9%) showed a misclassified HCV genotype, probably causing DAA failure, 16 had been treated with a sub-optimal DAA regimen, 19 with a simeprevir-based regimen and 39 with an optimal DAA regimen. A major RAS was identified more frequently in the simeprevir regimen group (68.4%) and in the optimal regimen group (74.4%) than in the sub-optimal regimen group (56.3%). The prevalence of RASs in NS3 was similar in the three groups (30.8-57.9%), that in NS5A higher in the optimal regimen group (71.8%) than in the sub-optimal regimen group (12.5%, P < 0.0001) and in the simeprevir regimen group (31.6%, P < 0.0005), and that in NS5B low in all groups (0-25%). RASs in two or more HCV regions were more frequently identified in the optimal regimen group (46.6%) than in the simeprevir-based regimen group (31.6%) and sub-optimal regimen group (18.7%). In our real-life population the prevalence of RASs was high, especially in NS3 and NS5A and in those treated with suitable DAA regimens. © 2018 Wiley Periodicals, Inc.

Metallurgical causes for the occurrence of creep damage in longitudinally seam-welded Cr-Mo high-energy piping

NASA Astrophysics Data System (ADS)

Zhou, Gang

A continuous occurrence of catastrophic failures, leaks and cracks of the Cr-Mo steam piping has created widespread utility concern for the integrity and serviceability of the seam-welded piping systems in power plants across USA. Cr-Mo steels are the materials widely used for elevated temperature service in fossil-fired generating stations. A large percentage of the power plant units with the Cr-Mo seam-welded steam piping have been in operation for a long duration such that the critical components of the units have been employed beyond the design life (30 or 40 years). This percentage will increase even more significantly in the near future. There is a strong desire to extend and thus there is a need to assess the remaining life of these units. Thus, understanding of the metallurgical causes for the failures and damage in the Cr-Mo seam-welded piping plays a major role in estimating possible life-extension and decision making on whether to operate, repair or replace. In this study, an optical metallographic method and a Cryo-Crack fractographic method have been developed for characterization and quantification of the damage in seam-welded steam piping. More than 500 metallographic assessments, from more than 25 power plants, have been accomplished using the optical metallographic method, and more than 200 fractographic specimens from 10 power plants have been evaluated using the "Cryo-Crack" fractographic technique. For comparison, "virgin" SA welds were fabricated using the Mohave welding procedure with re-N&T Mohave base metal with both "acid" and "basic" fluxes. The damage mechanism, damage distribution pattern, damage classification, correlation of the damage with the microstructural features of these SA welds and the impurity segregation patterns have been determined. A physical model for cavitation (leading to failure) in Cr-Mo SA weld metals and evaluation methodologies for high energy piping are proposed.

Controls on radon emission from granite as evidenced by compression testing to failure

NASA Astrophysics Data System (ADS)

Koike, Katsuaki; Yoshinaga, Tohru; Suetsugu, Kenta; Kashiwaya, Koki; Asaue, Hisafumi

2015-10-01

A set of uniaxial compression tests of granite specimens taken from five localities across Japan was conducted to identify the factors controlling the quantity of radon (Rn) emission (sum of 222Rn and 220Rn) during compression and failure. An α-scintillation detector and a gas flow unit were installed with a testing machine to enable continuous measurement of Rn emissions. Common to all specimens, Rn emissions remained at or slightly declined from the background level after the start of loading; this is similar to the natural phenomenon of decline in groundwater-dissolved Rn before an earthquake. Closure of original microcracks is the most likely cause of the initial Rn decline. Then, Rn emissions begin to increase at 46-57 per cent stress level to the uniaxial compressive strength, and continue to increase even after the failure of specimen. This commencement stress level is close to the general stress level at outbreak of acoustic emissions caused by the development and connection of microcracks. The Rn increase after failure is similar to a phenomenon observed in aftershocks, which may originate from the enhancement of Rn emanations from grains due to the large increase in total surface area and stress release. In addition to the initial radioelement content in rock, the failure pattern (conjugate shear versus longitudinal tensile type), compressive strength, and grain size are possible control factors of the maximum quantity of Rn emissions induced by failure. This maximum may also be affected by the development velocity of the emanation area, which is related to the Rn emanation fraction, associated with the fragmentation. In addition to the magnitude of an earthquake and its hypocentre distance to Rn detectors, the magnitude of increase in Rn concentration in soil gas and groundwater before, during, and after an earthquake in crystalline rocks depends on the intrinsic radioelement content, the mineral texture, and the mechanical properties of rocks. Rock fracturing and failure do not necessarily induce increase in Rn emission due to these rock properties, which can be used to understand the sensitivity of Rn concentration in soil gas or groundwater in connection with an earthquake.

Application of multi attribute failure mode analysis of milk production using analytical hierarchy process method

NASA Astrophysics Data System (ADS)

Rucitra, A. L.

2018-03-01

Pusat Koperasi Induk Susu (PKIS) Sekar Tanjung, East Java is one of the modern dairy industries producing Ultra High Temperature (UHT) milk. A problem that often occurs in the production process in PKIS Sekar Tanjung is a mismatch between the production process and the predetermined standard. The purpose of applying Analytical Hierarchy Process (AHP) was to identify the most potential cause of failure in the milk production process. Multi Attribute Failure Mode Analysis (MAFMA) method was used to eliminate or reduce the possibility of failure when viewed from the failure causes. This method integrates the severity, occurrence, detection, and expected cost criteria obtained from depth interview with the head of the production department as an expert. The AHP approach was used to formulate the priority ranking of the cause of failure in the milk production process. At level 1, the severity has the highest weight of 0.41 or 41% compared to other criteria. While at level 2, identifying failure in the UHT milk production process, the most potential cause was the average mixing temperature of more than 70 °C which was higher than the standard temperature (≤70 ° C). This failure cause has a contributes weight of 0.47 or 47% of all criteria Therefore, this study suggested the company to control the mixing temperature to minimise or eliminate the failure in this process.

Failure analysis of aluminum alloy components

NASA Technical Reports Server (NTRS)

Johari, O.; Corvin, I.; Staschke, J.

1973-01-01

Analysis of six service failures in aluminum alloy components which failed in aerospace applications is reported. Identification of fracture surface features from fatigue and overload modes was straightforward, though the specimens were not always in a clean, smear-free condition most suitable for failure analysis. The presence of corrosion products and of chemically attacked or mechanically rubbed areas here hindered precise determination of the cause of crack initiation, which was then indirectly inferred from the scanning electron fractography results. In five failures the crack propagation was by fatigue, though in each case the fatigue crack initiated from a different cause. Some of these causes could be eliminated in future components by better process control. In one failure, the cause was determined to be impact during a crash; the features of impact fracture were distinguished from overload fractures by direct comparisons of the received specimens with laboratory-generated failures.

Prophylactic augmentation of the proximal femur: an investigation of two techniques.

PubMed

Raas, Christoph; Hofmann-Fliri, Ladina; Hörmann, Romed; Schmoelz, Werner

2016-03-01

Osteoporotic hip fractures are an increasing problem in an ageing population. They result in high morbidity, mortality and high socioeconomic costs. For patients with poor bone quality, prophylactic augmentation of the proximal femur might be an option for fracture prevention. In two groups of paired human femora the potential of limited polymethyl-methacrylate (PMMA) augmentation (11-15 ml) in a V-shape pattern and the insertion of a proximal femur nail antirotation (PFNA) blade were investigated. The testing was carried out pair wise simulating the single leg stand. The untreated femur in each pair served as control. An axial load was applied until failure. Load displacement parameters and temperature increase during the augmentation process were recorded. In the PMMA group no significant difference was found between the augmented and non-augmented specimen concerning load to failure (p = 0.35) and energy to failure (p = 0.9). A median temperature increase of 9.5 °C was observed in the augmented specimen. A significant correlation was found between the amount of applied PMMA and the temperature increase (Cor. Coef. = 0.82, p = 0.042). In the PFNA group, a significant decrease of load to failure and a non-significant decrease of energy to failure were observed (p = 0.037 and p = 0.075). Limited V-shaped PMMA augmentation and PFNA blade insertion did not show any improvement in failure load or energy to failure. Volumes of up to 15 ml PMMA did not cause a critical surface temperature increase.

[Chronic heart failure].

PubMed

Gosch, Markus

2008-08-01

As a consequence of the increasing life expectancy the number of patients suffering from chronic heart failure has been growing continuously in the past few decades, especially in the group of the old and oldest. Frailty is a clinical syndrome that geriatricians attach great importance to. Like many other diseases chronic heart failure can cause frailty. Based on the experience that we see only a small correlation between the functional capacity of patients with heart failure and the results of cardiological findings, the model of peripheral myopathy in chronic heart failure was developed. Different pathophysiological changes may cause the increasing exercise intolerance in patients with chronic heart failure. We can already consider different experimental approaches to the therapy of frailty caused by chronic heart failure. At the moment we have to focus our efforts on an optimal therapy of heart failure, especially with angiotensin-converting-enzyme inhibitors and beta-blockers, and on individual endurance and strength training.

A Complex Network Analysis of Granular Fabric Evolution in Three-Dimensions

DTIC Science & Technology

2011-01-01

organized pattern formation (e.g., strain localization), and co-evolution of emergent in- ternal structures (e.g., force cycles and force chains) [15...these networks, particularly recurring patterns or motifs, and understanding how these co-evolve are crucial to the robust characterization and...the lead up to and during failure. Since failure patterns and boundaries of flow in three-dimensional specimens can be quite complicated and difficult

Patterns of Care and Disparities in the Treatment of Early Breast Cancer

DTIC Science & Technology

2008-09-30

renal impairment in heart failure : mortality in blacks versus whites. Circulation. 2005 Mar 15;111(10):1270-7. 19. Smith BD, Smith GL, Haffty BG...Lichtman JH, Krumholz HM. Functional status and quality of life in heart failure patients with renal impairment. Circulation 106(16):e76, 2002...Theses 1. Ph.D.: Smith GL. Renal Impairment in Heart Failure : Prevalence, Prognosis, and Detection. 2007. 41 2. M.D.: Smith GL. Patterns of

Correlated seed failure as an environmental veto to synchronize reproduction of masting plants.

PubMed

Bogdziewicz, Michał; Steele, Michael A; Marino, Shealyn; Crone, Elizabeth E

2018-07-01

Variable, synchronized seed production, called masting, is a widespread reproductive strategy in plants. Resource dynamics, pollination success, and, as described here, environmental veto are possible proximate mechanisms driving masting. We explored the environmental veto hypothesis, which assumes that reproductive synchrony is driven by external factors preventing reproduction in some years, by extending the resource budget model of masting with correlated reproductive failure. We ran this model across its parameter space to explore how key parameters interact to drive seeding dynamics. Next, we parameterized the model based on 16 yr of seed production data for populations of red (Quercus rubra) and white (Quercus alba) oaks. We used these empirical models to simulate seeding dynamics, and compared simulated time series with patterns observed in the field. Simulations showed that resource dynamics and reproduction failure can produce masting even in the absence of pollen coupling. In concordance with this, in both oaks, among-year variation in resource gain and correlated reproductive failure were necessary and sufficient to reproduce masting, whereas pollen coupling, although present, was not necessary. Reproductive failure caused by environmental veto may drive large-scale synchronization without density-dependent pollen limitation. Reproduction-inhibiting weather events are prevalent in ecosystems, making described mechanisms likely to operate in many systems. © 2018 The Authors New Phytologist © 2018 New Phytologist Trust.

Characteristics of Non-Cohesive Embankment Failure

NASA Astrophysics Data System (ADS)

Yusof, Z. M.; Wahab, A. K. A.; Ismail, Z.; Amerudin, S.

2018-04-01

Embankments are important infrastructure built to provide flood control. They also present risks to property and life due to their potential to fail and cause catastrophic flooding. To mitigate these risks, authorities and regulators need to carefully analyse and inspect dams to identify potential failure modes and protect against them. This paper presents morphology of an embankment study and its sediment behaviour of different grain sizes after the embankment fails. A few experiments were carried out for the embankment size of 1V:3H with different sediment grain sizes; medium and coarser sand. The embankment material used is non-cohesive soil with the embankment height of 0.1 m. The embankment is tested with inflows rate of Q = 0.8 L/s. Experimental results showed the peak discharge for the same inflow rate is affected by the shape of embankment breached. The peak discharge of medium grain size of the embankment is highest, which gave 3.63 L/s in comparison with a coarser embankment. This concludes that the embankment morphology patterns are dissimilar to each other. The flow and dimension of embankment are shown to influence the characteristics of embankment failure.

CGGBP1 is a nuclear and midbody protein regulating abscission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Umashankar, E-mail: umashankar.singh@genpat.uu.se; Westermark, Bengt

2011-01-15

Abscission marks the completion of cell division and its failure is associated with delayed cytokinesis and even tetraploidization. Aberrant abscission and consequential ploidy changes can underlie various diseases including cancer. Midbody, a transient structure formed in the intercellular bridge during telophase, contains several proteins including Aurora kinase B (AURKB), which participate in abscission. We report here an unexpected expression pattern and function of the transcription repressor protein CGG triplet repeat-binding protein 1 (CGGBP1), in normal human fibroblasts. We show that CGGBP1, a chromatin-associated protein, trans-localizes to spindle midzone and midbodies in a manner similar to that of AURKB. CGGBP1 depletionmore » resulted in a cell cycle block at G2, characterized by failure of cells to undergo mitosis and also reduced entry into S phase. Consistent with its presence in the midbodies, live microscopy showed that CGGBP1 deficiency caused mitotic failure at abscission resulting in tetraploidy, which could be rescued by CGGBP1 overexpression. These results show that CGGBP1 is a bona fide midbody protein required for normal abscission and mitosis in general.« less

Thoracentesis

MedlinePlus

... the layers of the pleura is called a pleural effusion . The test is performed to determine the cause ... will help your provider determine the cause of pleural effusion. Possible causes include: Cancer Liver failure Heart failure ...

Spatial variation of heart failure and air pollution in Warwickshire, UK: an investigation of small scale variation at the ward-level.

PubMed

Bennett, Oscar; Kandala, Ngianga-Bakwin; Ji, Chen; Linnane, John; Clarke, Aileen

2014-12-02

To map using geospatial modelling techniques the morbidity and mortality caused by heart failure within Warwickshire to characterise and quantify any influence of air pollution on these risks. Cross-sectional. Warwickshire, UK. Data from all of the 105 current Warwickshire County wards were collected on hospital admissions and deaths due to heart failure. In multivariate analyses, the presence of higher mono-nitrogen oxide (NOx) in a ward (3.35:1.89, 4.99), benzene (Ben) (31.9:8.36, 55.85) and index of multiple deprivation (IMD; 0.02: 0.01, 0.03), were consistently associated with a higher risk of heart failure morbidity. Particulate matter (Pm; -12.93: -20.41, -6.54) was negatively associated with the risk of heart failure morbidity. No association was found between sulfur dioxide (SO2) and heart failure morbidity. The risk of heart failure mortality was higher in wards with a higher NOx (4.30: 1.68, 7.37) and wards with more inhabitants 50+ years old (1.60: 0.47, 2.92). Pm was negatively associated (-14.69: -23.46, -6.50) with heart failure mortality. SO2, Ben and IMD scores were not associated with heart failure mortality. There was a prominent variation in heart failure morbidity and mortality risk across wards, the highest risk being in the regions around Nuneaton and Bedworth. This study showed distinct spatial patterns in heart failure morbidity and mortality, suggesting the potential role of environmental factors beyond individual-level risk factors. Air pollution levels should therefore be taken into account when considering the wider determinants of public health and the impact that changes in air pollution might have on the health of a population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Spatial variation of heart failure and air pollution in Warwickshire, UK: an investigation of small scale variation at the ward-level

PubMed Central

Bennett, Oscar; Kandala, Ngianga-Bakwin; Ji, Chen; Linnane, John; Clarke, Aileen

2014-01-01

Objectives To map using geospatial modelling techniques the morbidity and mortality caused by heart failure within Warwickshire to characterise and quantify any influence of air pollution on these risks. Design Cross-sectional. Setting Warwickshire, UK. Participants Data from all of the 105 current Warwickshire County wards were collected on hospital admissions and deaths due to heart failure. Results In multivariate analyses, the presence of higher mono-nitrogen oxide (NOx) in a ward (3.35:1.89, 4.99), benzene (Ben) (31.9:8.36, 55.85) and index of multiple deprivation (IMD; 0.02: 0.01, 0.03), were consistently associated with a higher risk of heart failure morbidity. Particulate matter (Pm; −12.93: −20.41, −6.54) was negatively associated with the risk of heart failure morbidity. No association was found between sulfur dioxide (SO2) and heart failure morbidity. The risk of heart failure mortality was higher in wards with a higher NOx (4.30: 1.68, 7.37) and wards with more inhabitants 50+ years old (1.60: 0.47, 2.92). Pm was negatively associated (−14.69: −23.46, −6.50) with heart failure mortality. SO2, Ben and IMD scores were not associated with heart failure mortality. There was a prominent variation in heart failure morbidity and mortality risk across wards, the highest risk being in the regions around Nuneaton and Bedworth. Conclusions This study showed distinct spatial patterns in heart failure morbidity and mortality, suggesting the potential role of environmental factors beyond individual-level risk factors. Air pollution levels should therefore be taken into account when considering the wider determinants of public health and the impact that changes in air pollution might have on the health of a population. PMID:25468504

33 CFR 20.705 - Failure to appear.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Failure to appear. 20.705 Section....705 Failure to appear. The ALJ may enter a default under § 20.310 against a respondent threatening to... days or less after an order to show good cause, the respondent shows good cause for his or her failure...

33 CFR 20.705 - Failure to appear.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Failure to appear. 20.705 Section....705 Failure to appear. The ALJ may enter a default under § 20.310 against a respondent threatening to... days or less after an order to show good cause, the respondent shows good cause for his or her failure...

33 CFR 20.705 - Failure to appear.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Failure to appear. 20.705 Section....705 Failure to appear. The ALJ may enter a default under § 20.310 against a respondent threatening to... days or less after an order to show good cause, the respondent shows good cause for his or her failure...

33 CFR 20.705 - Failure to appear.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Failure to appear. 20.705 Section....705 Failure to appear. The ALJ may enter a default under § 20.310 against a respondent threatening to... days or less after an order to show good cause, the respondent shows good cause for his or her failure...

33 CFR 20.705 - Failure to appear.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Failure to appear. 20.705 Section....705 Failure to appear. The ALJ may enter a default under § 20.310 against a respondent threatening to... days or less after an order to show good cause, the respondent shows good cause for his or her failure...

Modeling Common Cause Failures of Thrusters on ISS Visiting Vehicles

NASA Technical Reports Server (NTRS)

Haught, Megan

2014-01-01

This paper discusses the methodology used to model common cause failures of thrusters on the International Space Station (ISS) Visiting Vehicles. The ISS Visiting Vehicles each have as many as 32 thrusters, whose redundancy makes them susceptible to common cause failures. The Global Alpha Model (as described in NUREG/CR-5485) can be used to represent the system common cause contribution, but NUREG/CR-5496 supplies global alpha parameters for groups only up to size six. Because of the large number of redundant thrusters on each vehicle, regression is used to determine parameter values for groups of size larger than six. An additional challenge is that Visiting Vehicle thruster failures must occur in specific combinations in order to fail the propulsion system; not all failure groups of a certain size are critical.

Failure of endodontic treatment: The usual suspects.

PubMed

Tabassum, Sadia; Khan, Farhan Raza

2016-01-01

Inappropriate mechanical debridement, persistence of bacteria in the canals and apex, poor obturation quality, over and under extension of the root canal filling, and coronal leakage are some of the commonly attributable causes of failure. Despite the high success rate of endodontic treatment, failures do occur in a large number of cases and most of the times can be attributed to the already stated causes. With an ever increasing number of endodontic treatments being done each day, it has become imperative to avoid or minimize the most fundamental of reasons leading to endodontic failure. This paper reviews the most common causes of endodontic failure along with radiographic examples.

Failure of endodontic treatment: The usual suspects

PubMed Central

Tabassum, Sadia; Khan, Farhan Raza

2016-01-01

Inappropriate mechanical debridement, persistence of bacteria in the canals and apex, poor obturation quality, over and under extension of the root canal filling, and coronal leakage are some of the commonly attributable causes of failure. Despite the high success rate of endodontic treatment, failures do occur in a large number of cases and most of the times can be attributed to the already stated causes. With an ever increasing number of endodontic treatments being done each day, it has become imperative to avoid or minimize the most fundamental of reasons leading to endodontic failure. This paper reviews the most common causes of endodontic failure along with radiographic examples. PMID:27011754

Brugada syndrome in a patient with amyotrophic lateral sclerosis: a case report.

PubMed

Battineni, Anusha; Gummi, Rohit; Mullaguri, Naresh; Govindarajan, Raghav

2017-07-14

Amyotrophic lateral sclerosis is a fatal neuromuscular disorder characterized by progressive death of the upper and lower motor neurons in the central nervous system. Patients with this disease die mostly as a result of respiratory failure; however, owing to prolonged survival through assisted ventilation, cardiovascular causes are increasingly responsible for mortality. We report what is to the best of our knowledge the first case of type 2 Brugada syndrome causing ventricular tachyarrhythmia and cardiac arrest in a patient with upper limb onset amyotrophic lateral sclerosis. A 48-year-old Caucasian woman with a significant past medical history of papillary thyroid carcinoma status postresection, pulmonary embolism on anticoagulation, and a recent diagnosis of right upper limb-onset amyotrophic lateral sclerosis presented to the emergency department of our hospital with acute on chronic shortness of breath. On further evaluation, she was found to have hypoxic and hypercapnic respiratory failure and was placed on bilevel positive airway pressure ventilation. Her 12-lead electrocardiogram showed sinus rhythm with J-point elevation, saddle-shaped ST segment elevation, predominantly in V1 and V2 with no significant QTc prolongation. No troponin elevation was noted in her laboratory workup. Because she was unable to protect her airway, a decision was made to intubate her. After 1 minute of induction with etomidate and succinylcholine, she went into pulseless ventricular tachycardia and fibrillation requiring three cycles of cardiopulmonary resuscitation with high-quality chest compressions, three doses of epinephrine, and a loading dose of amiodarone prior to return of spontaneous circulation. She was further evaluated by cardiology services and was diagnosed with type 2 Brugada syndrome, for which she was started on quinidine. Her respiratory failure and the drugs she received for intubation likely caused her ventricular tachycardia to occur in conjunction with an underlying Brugada pattern seen on an electrocardiogram. The results of evaluation of her genetic panel for Brugada syndrome were negative. She was subsequently discharged to home in stable condition after a 10-day hospital stay. Amyotrophic lateral sclerosis is a progressive neuromuscular disorder with significant mortality. Respiratory failure is the leading cause of death, but lately, owing to increased survival associated with early tracheostomy and positive pressure ventilation, there has been an increasing trend in the identification of cardiovascular causes of mortality, especially arrhythmias, that may need periodic electrocardiographic surveillance.

A portable pattern-based design technology co-optimization flow to reduce optical proximity correction run-time

NASA Astrophysics Data System (ADS)

Chen, Yi-Chieh; Li, Tsung-Han; Lin, Hung-Yu; Chen, Kao-Tun; Wu, Chun-Sheng; Lai, Ya-Chieh; Hurat, Philippe

2018-03-01

Along with process improvement and integrated circuit (IC) design complexity increased, failure rate caused by optical getting higher in the semiconductor manufacture. In order to enhance chip quality, optical proximity correction (OPC) plays an indispensable rule in the manufacture industry. However, OPC, includes model creation, correction, simulation and verification, is a bottleneck from design to manufacture due to the multiple iterations and advanced physical behavior description in math. Thus, this paper presented a pattern-based design technology co-optimization (PB-DTCO) flow in cooperation with OPC to find out patterns which will negatively affect the yield and fixed it automatically in advance to reduce the run-time in OPC operation. PB-DTCO flow can generate plenty of test patterns for model creation and yield gaining, classify candidate patterns systematically and furthermore build up bank includes pairs of match and optimization patterns quickly. Those banks can be used for hotspot fixing, layout optimization and also be referenced for the next technology node. Therefore, the combination of PB-DTCO flow with OPC not only benefits for reducing the time-to-market but also flexible and can be easily adapted to diversity OPC flow.

Nonacetaminophen Drug-Induced Acute Liver Failure.

PubMed

Thomas, Arul M; Lewis, James H

2018-05-01

Acute liver failure of all causes is diagnosed in between 2000 and 2500 patients annually in the United States. Drug-induced acute liver failure is the leading cause of acute liver failure, accounting for more than 50% of cases. Nonacetaminophen drug injury represents 11% of all cases in the latest registry from the US Acute Liver Failure Study Group. Although rare, acute liver failure is clinically dramatic when it occurs, and requires a multidisciplinary approach to management. In contrast with acetaminophen-induced acute liver failure, non-acetaminophen-induced acute liver failure has a more ominous prognosis with a lower liver transplant-free survival. Copyright © 2018 Elsevier Inc. All rights reserved.

PARTITIONING RISK AMONG DIFFERENT SOURCES OF NEST FAILURE

EPA Science Inventory

Nest predation and nest parasitism receive the most attention as causes of nest failure for North American songbirds. Yet for many populations, interspecific competition, adverse weather, abandonment, nestling starvation, and

egg failure may also be significant causes of n...

Cost of Lightning Strike Related Outages of Visual Navigational Aids at Airports in the United States

NASA Astrophysics Data System (ADS)

Rakas, J.; Nikolic, M.; Bauranov, A.

2017-12-01

Lightning storms are a serious hazard that can cause damage to vital human infrastructure. In aviation, lightning strikes cause outages to air traffic control equipment and facilities that result in major disruptions in the network, causing delays and financial costs measured in the millions of dollars. Failure of critical systems, such as Visual Navigational Aids (Visual NAVAIDS), are particularly dangerous since NAVAIDS are an essential part of landing procedures. Precision instrument approach, an operation utilized during the poor visibility conditions, utilizes several of these systems, and their failure leads to holding patterns and ultimately diversions to other airports. These disruptions lead to both ground and airborne delay. Accurate prediction of these outages and their costs is a key prerequisite for successful investment planning. The air traffic management and control sector need accurate information to successfully plan maintenance and develop a more robust system under the threat of increasing lightning rates. To analyze the issue, we couple the Remote Monitoring and Logging System (RMLS) database and the Aviation System Performance Metrics (ASPM) databases to identify lightning-induced outages, and connect them with weather conditions, demand and landing runway to calculate the total delays induced by the outages, as well as the number of cancellations and diversions. The costs are then determined by calculating direct costs to aircraft operators and costs of passengers' time for delays, cancellations and diversions. The results indicate that 1) not all NAVAIDS are created equal, and 2) outside conditions matter. The cost of an outage depends on the importance of the failed system and the conditions that prevailed before, during and after the failure. The outage that occurs during high demand and poor weather conditions is more likely to result in more delays and higher costs.

A Rolling Element Bearing Fault Diagnosis Approach Based on Multifractal Theory and Gray Relation Theory

PubMed Central

Li, Jingchao; Cao, Yunpeng; Ying, Yulong; Li, Shuying

2016-01-01

Bearing failure is one of the dominant causes of failure and breakdowns in rotating machinery, leading to huge economic loss. Aiming at the nonstationary and nonlinear characteristics of bearing vibration signals as well as the complexity of condition-indicating information distribution in the signals, a novel rolling element bearing fault diagnosis method based on multifractal theory and gray relation theory was proposed in the paper. Firstly, a generalized multifractal dimension algorithm was developed to extract the characteristic vectors of fault features from the bearing vibration signals, which can offer more meaningful and distinguishing information reflecting different bearing health status in comparison with conventional single fractal dimension. After feature extraction by multifractal dimensions, an adaptive gray relation algorithm was applied to implement an automated bearing fault pattern recognition. The experimental results show that the proposed method can identify various bearing fault types as well as severities effectively and accurately. PMID:28036329

A Rolling Element Bearing Fault Diagnosis Approach Based on Multifractal Theory and Gray Relation Theory.

PubMed

Li, Jingchao; Cao, Yunpeng; Ying, Yulong; Li, Shuying

2016-01-01

Bearing failure is one of the dominant causes of failure and breakdowns in rotating machinery, leading to huge economic loss. Aiming at the nonstationary and nonlinear characteristics of bearing vibration signals as well as the complexity of condition-indicating information distribution in the signals, a novel rolling element bearing fault diagnosis method based on multifractal theory and gray relation theory was proposed in the paper. Firstly, a generalized multifractal dimension algorithm was developed to extract the characteristic vectors of fault features from the bearing vibration signals, which can offer more meaningful and distinguishing information reflecting different bearing health status in comparison with conventional single fractal dimension. After feature extraction by multifractal dimensions, an adaptive gray relation algorithm was applied to implement an automated bearing fault pattern recognition. The experimental results show that the proposed method can identify various bearing fault types as well as severities effectively and accurately.

Survey of Failure in Engineering Education and Industry

NASA Astrophysics Data System (ADS)

Arimitsu, Yutaka; Yagi, Hidetsugu

Students have failure experiences in the project-based learning but they do not profess their experiences. On the other hand, failures and accidents, in the industrial world, are analyzed frequently, and a knowledge data base on failure and QC activities have been introduced. To turn failure experience in education to advantage, the authors survey the properties of failures in project based learning and views of students, teachers and managers of design divisions in companies. Teachers and students regard failure experiences as instructive and acceptable. The typical causes of failure in educational institutions are luck of skill in manufacturing and inadequate planning, which are minor causes of failure in the industry. To establish a knowledge data base on failure in educational institutions, properties of failure in education should be taken into account.

Development and validation of a liquid chromatography-mass spectrometry metabonomic platform in human plasma of liver failure caused by hepatitis B virus.

PubMed

Zhang, Lijun; Jia, Xiaofang; Peng, Xia; Ou, Qiang; Zhang, Zhengguo; Qiu, Chao; Yao, Yamin; Shen, Fang; Yang, Hua; Ma, Fang; Wang, Jiefei; Yuan, Zhenghong

2010-10-01

This paper presents an liquid chromatography (LC)/mass spectrometry (MS)-based metabonomic platform that combined the discovery of differential metabolites through principal component analysis (PCA) with the verification by selective multiple reaction monitoring (MRM). These methods were applied to analyze plasma samples from liver disease patients and healthy donors. LC-MS raw data (about 1000 compounds), from the plasma of liver failure patients (n = 26) and healthy controls (n = 16), were analyzed through the PCA method and a pattern recognition profile that had significant difference between liver failure patients and healthy controls (P < 0.05) was established. The profile was verified in 165 clinical subjects. The specificity and sensitivity of this model in predicting liver failure were 94.3 and 100.0%, respectively. The differential ions with m/z of 414.5, 432.0, 520.5, and 775.0 were verified to be consistent with the results from PCA by MRM mode in 40 clinical samples, and were proved not to be caused by the medicines taken by patients through rat model experiments. The compound with m/z of 520.5 was identified to be 1-Linoleoylglycerophosphocholine or 1-Linoleoylphosphatidylcholine through exact mass measurements performed using Ion Trap-Time-of-Flight MS and METLIN Metabolite Database search. In all, it was the first time to integrate metabonomic study and MRM relative quantification of differential peaks in a large number of clinical samples. Thereafter, a rat model was used to exclude drug effects on the abundance of differential ion peaks. 1-Linoleoylglycerophosphocholine or 1-Linoleoylphosphatidylcholine, a potential biomarker, was identified. The LC/MS-based metabonomic platform could be a powerful tool for the metabonomic screening of plasma biomarkers.

Crack propagation and coalescence due to dual non-penetrating surface flaws and their effect on the strength of rock-like material

NASA Astrophysics Data System (ADS)

Xu, Jun; Zheng, Zheyuan; Xiao, Xiaochun; Li, Zhaoxia

2018-06-01

Non-penetrating surface flaws play a key role in the fracture process of rock-like material, and could cause localized collapse and even failure of the materials. Until now, the mechanism and the effect of surface crack propagation have remained unclear. In this paper, compression tests on gypsum (a soft rock material) are conducted to investigate crack propagation and coalescence due to non-penetrating surface flaws and their effect on the material strength. Specimens are tested under dual pre-existing surface flaws with various combinations of depth and spacing. The results show that when the pre-existing flaws are non-penetrating, the d/t ratio (flaw depth ratio, d is the pre-existing flaw cutting depth and t is the specimen thickness) and the spacing (the distance between the two flaw internal tips) have a strong influence on surface crack patterns and specimen strength. Few cracks emanate from the pre-existing flaws when the flaw depth ratio is equal to 1/3, and more cracks occur with the increase of the flaw depth ratio. When the pre-existing flaw penetrates completely through the specimen, the spacing has a small effect on the specimen strength. A larger flaw depth ratio could advance the occurrence of the peak load (PL) and result in a smaller specimen residual strength. The failure process of the specimen is divided into several stages featured by a stepped decline of the load value after PL, which is closely related to the initiation and propagation of secondary cracks. In addition, the spalling (failure of a portion of the surface caused by coalescence of cracks) can be regarded as indicating the failure of the specimen, and two possible types of spalling formation are briefly discussed.

Software For Fault-Tree Diagnosis Of A System

NASA Technical Reports Server (NTRS)

Iverson, Dave; Patterson-Hine, Ann; Liao, Jack

1993-01-01

Fault Tree Diagnosis System (FTDS) computer program is automated-diagnostic-system program identifying likely causes of specified failure on basis of information represented in system-reliability mathematical models known as fault trees. Is modified implementation of failure-cause-identification phase of Narayanan's and Viswanadham's methodology for acquisition of knowledge and reasoning in analyzing failures of systems. Knowledge base of if/then rules replaced with object-oriented fault-tree representation. Enhancement yields more-efficient identification of causes of failures and enables dynamic updating of knowledge base. Written in C language, C++, and Common LISP.

Pattern of cytokine (IL-6 and IL-10) level as inflammation and anti-inflammation mediator of multiple organ dysfunction syndrome (MODS) in polytrauma.

PubMed

Sapan, Heber Bombang; Paturusi, Idrus; Jusuf, Irawan; Patellongi, Ilhamjaya; Massi, Muh Nasrum; Pusponegoro, Aryono Djuned; Arief, Syafrie Kamsul; Labeda, Ibrahim; Islam, Andi Asadul; Rendy, Leo; Hatta, Mochammad

2016-01-01

Massive injury remains the most common cause of death for productive age group globally. The current immune, inflammatory paradigm, based on an incomplete understanding of the functional integration of the complex host response, remains a major impediment to the development of effective innovative diagnostic and therapeutic effort. This study attempt to investigate the pattern of inflammatory and anti-inflammatory cytokines such as interleukin-6 and 10 (IL-6 and IL-10) and their interaction in severe injury condition with its major complication as multiple organ dysfunction syndrome (MODS) and failure (MOF) after polytrauma. This is multicenter study held at 4 academic Level-1 Trauma center included 54 polytrauma participants. Inclusion criteria were age between 16-60 years old, had new acute episode of polytrauma which defined as injury in ≥2 body region with Injury Severity Score (ISS) ≥16, and the presence of Systemic Inflammation Response Syndrome (SIRS). Serum level of IL-6 and IL-10 were taken on day 2, 3, and 5 after trauma. During hospitalization, samples were observed for the occurrence of MODS or MOF using Sequential Organ Failure Assessment (SOFA) and mortality rate were also noted. Participant were mostly male with mean of age of 35, 9 years old, endured polytrauma caused by traffic accident. Elevation of cytokines (IL-6, IL-10, and IL-6/IL-10 ratio) had directly proportional with MODS and mortality. Threshold level of compensation for severe trauma is IL-6 of 50 pg/mL and trauma load of ISS ≥30. Inflammation reaction greater than this threshold level would result in downhill level of IL-6, IL-10, or IL-6/IL-10 ratio which associated with poor outcome (MODS and death). The elevation of these cytokines level were represent as compensation/adaptive immune system and its fall represent decompensating/failure of immune system after severe trauma. The pattern of IL-6 and IL-10 after polytrauma represent immune system effort to restore homeostasis. Besides cytokines interaction, there must be other factors that contribute to mortality and poor outcome after major trauma. Further study is needed to investigate genomic variant or polymorphism related to trauma.

Syndrome complex of bone marrow failure and pulmonary fibrosis predicts germline defects in telomerase

PubMed Central

Parry, Erin M.; Alder, Jonathan K.; Qi, Xiaodong; Chen, Julian J.-L.

2011-01-01

Mutations in the essential telomerase components hTERT and hTR cause dyskeratosis congenita, a bone marrow failure syndrome characterized by mucocutaneous features. Some (∼ 3%) sporadic aplastic anemia (AA) and idiopathic pulmonary fibrosis cases also carry mutations in hTERT and hTR. Even though it can affect clinical outcome, because the mutation frequency is rare, genetic testing is not standard. We examined whether the cooccurrence of bone marrow failure and pulmonary fibrosis in the same individual or family enriches for the presence of a telomerase mutation. Ten consecutive individuals with a total of 36 family members who fulfilled these criteria carried a germline mutant telomerase gene (100%). The mean age of onset for individuals with AA was significantly younger than that for those with pulmonary fibrosis (14 vs 51; P < .0001). Families displayed autosomal dominant inheritance and there was an evolving pattern of genetic anticipation, with the older generation primarily affected by pulmonary fibrosis and successive generations by bone marrow failure. The cooccurrence of AA and pulmonary fibrosis in a single patient or family is highly predictive for the presence of a germline telomerase defect. This diagnosis affects the choice of bone marrow transplantation preparative regimen and can prevent morbidity. PMID:21436073

Understanding the causes of kidney transplant failure: the dominant role of antibody-mediated rejection and nonadherence.

PubMed

Sellarés, J; de Freitas, D G; Mengel, M; Reeve, J; Einecke, G; Sis, B; Hidalgo, L G; Famulski, K; Matas, A; Halloran, P F

2012-02-01

We prospectively studied kidney transplants that progressed to failure after a biopsy for clinical indications, aiming to assign a cause to every failure. We followed 315 allograft recipients who underwent indication biopsies at 6 days to 32 years posttransplant. Sixty kidneys progressed to failure in the follow-up period (median 31.4 months). Failure was rare after T-cell-mediated rejection and acute kidney injury and common after antibody-mediated rejection or glomerulonephritis. We developed rules for using biopsy diagnoses, HLA antibody and clinical data to explain each failure. Excluding four with missing information, 56 failures were attributed to four causes: rejection 36 (64%), glomerulonephritis 10 (18%), polyoma virus nephropathy 4 (7%) and intercurrent events 6 (11%). Every rejection loss had evidence of antibody-mediated rejection by the time of failure. Among rejection losses, 17 of 36 (47%) had been independently identified as nonadherent by attending clinicians. Nonadherence was more frequent in patients who progressed to failure (32%) versus those who survived (3%). Pure T-cell-mediated rejection, acute kidney injury, drug toxicity and unexplained progressive fibrosis were not causes of loss. This prospective cohort indicates that many actual failures after indication biopsies manifest phenotypic features of antibody-mediated or mixed rejection and also underscores the major role of nonadherence. © 2011 The American Society of Transplantation and the American Society of Transplant Surgeons.

A new algorithm for finding survival coefficients employed in reliability equations

NASA Technical Reports Server (NTRS)

Bouricius, W. G.; Flehinger, B. J.

1973-01-01

Product reliabilities are predicted from past failure rates and reasonable estimate of future failure rates. Algorithm is used to calculate probability that product will function correctly. Algorithm sums the probabilities of each survival pattern and number of permutations for that pattern, over all possible ways in which product can survive.

Modeling Common Cause Failures of Thrusters on ISS Visiting Vehicles

NASA Technical Reports Server (NTRS)

Haught, Megan; Duncan, Gary

2014-01-01

This paper discusses the methodology used to model common cause failures of thrusters on the International Space Station (ISS) Visiting Vehicles. The ISS Visiting Vehicles each have as many as 32 thrusters, whose redundancy and similar design make them susceptible to common cause failures. The Global Alpha Model (as described in NUREG/CR-5485) can be used to represent the system common cause contribution, but NUREG/CR-5496 supplies global alpha parameters for groups only up to size six. Because of the large number of redundant thrusters on each vehicle, regression is used to determine parameter values for groups of size larger than six. An additional challenge is that Visiting Vehicle thruster failures must occur in specific combinations in order to fail the propulsion system; not all failure groups of a certain size are critical.

Anabolic steroid-induced cardiomyopathy underlying acute liver failure in a young bodybuilder.

PubMed

Bispo, Miguel; Valente, Ana; Maldonado, Rosário; Palma, Rui; Glória, Helena; Nóbrega, João; Alexandrino, Paula

2009-06-21

Heart failure may lead to subclinical circulatory disturbances and remain an unrecognized cause of ischemic liver injury. We present the case of a previously healthy 40-year-old bodybuilder, referred to our Intensive-Care Unit of Hepatology for treatment of severe acute liver failure, with the suspicion of toxic hepatitis associated with anabolic steroid abuse. Despite the absence of symptoms and signs of congestive heart failure at admission, an anabolic steroid-induced dilated cardiomyopathy with a large thrombus in both ventricles was found to be the underlying cause of the liver injury. Treatment for the initially unrecognized heart failure rapidly restored liver function to normal. To our knowledge, this is the first reported case of severe acute liver failure due to an unrecognized anabolic steroid-induced cardiomyopathy. Awareness of this unique presentation will allow for prompt treatment of this potentially fatal cause of liver failure.

Managing Errors to Reduce Accidents in High Consequence Networked Information Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganter, J.H.

1999-02-01

Computers have always helped to amplify and propagate errors made by people. The emergence of Networked Information Systems (NISs), which allow people and systems to quickly interact worldwide, has made understanding and minimizing human error more critical. This paper applies concepts from system safety to analyze how hazards (from hackers to power disruptions) penetrate NIS defenses (e.g., firewalls and operating systems) to cause accidents. Such events usually result from both active, easily identified failures and more subtle latent conditions that have resided in the system for long periods. Both active failures and latent conditions result from human errors. We classifymore » these into several types (slips, lapses, mistakes, etc.) and provide NIS examples of how they occur. Next we examine error minimization throughout the NIS lifecycle, from design through operation to reengineering. At each stage, steps can be taken to minimize the occurrence and effects of human errors. These include defensive design philosophies, architectural patterns to guide developers, and collaborative design that incorporates operational experiences and surprises into design efforts. We conclude by looking at three aspects of NISs that will cause continuing challenges in error and accident management: immaturity of the industry, limited risk perception, and resource tradeoffs.« less

Analysis of L-band Multi-Channel Sea Clutter

DTIC Science & Technology

2010-08-01

Some researchers found that the use of a hybrid algorithm of PS and GA could accelerate the convergence for array beamforming designs (Yeo and Lu...to be shown is array failure correction using the PS algorithm . Assume element 5 of a 32 half-wavelength spacing linear array is in failure. The goal... algorithm . The blue one is the 20 dB Chebyshev pattern and the template in red is the goal pattern to achieve. Two corrected beam patterns are

Nest success, cause-specific nest failure, and hatchability of aquatic birds at selenium-contaminated Kesterson Reservoir and a reference site

USGS Publications Warehouse

Ohlendorf, Harry M.; Hothem, Roger L.; Welsh, Daniel

1989-01-01

During 1983-1985, we studied the reproductive success of several species of aquatic birds (coots, ducks, shorebirds, and grebes) nesting at two sites in Merced County, California: a selenium-contaminated site (Kesterson Reservoir) and a nearby reference site (Volta Wildlife Area). We used a computer program (MICROMORT) developed for the analysis of radiotelemetry data (Heisey and Fuller 1985) to estimate nest success and cause-specific failure rates, and then compared these parameters and hatchability between sites and among years. Nest success and causes of failure varied by species, site, and year. The most important causes of nest failure were usually predation, desertion, and water-level changes. However, embryotoxicosis (mortality, deformity, and lack of embryonic development) was the most important cause of nest failure in Eared Grebes (Podiceps nigricollis) at Kesterson Reservoir. Embryotoxicosis also reduced the hatchability of eggs of all other species at Kesterson in one or more years; embryonic mortality occurred rarely at Volta, and abnormalities were not observed.

Seeing more clearly through the fog of encephalopathy.

PubMed

Kaplan, Peter W; Sutter, Raoul

2013-10-01

Patients with acute confusional states (often referred to as encephalopathy or delirium) pose diagnostic and management challenges for treating physicians. Encephalopathy is associated with a high morbidity and mortality rate, and the diagnosis rests on clinical grounds but may also be supported by the finding of electroencephalographic (EEG) evidence for diffuse cerebral dysfunction. The myriad cerebral transmitter and metabolic disruptions are generated by systemic organ system failures, principal among which are those of the liver, kidneys, lungs, heart, and endocrine system, along with the effects of exogenous toxins and medications. In most cases, several of these organ failures together contribute to the confusional state, frequently in the context of a diffuse cerebral atrophy that affects the aging brain. This special issue of the Journal of Clinical Neurophysiology is dedicated to exploring the electrophysiology of these conditions. It reviews the pathophysiology, psychiatric manifestations, clinical and imaging correlations of the many causes and types of encephalopathy. A literature review of the EEG abnormalities in the various types of encephalopathy provides an overview that ranges from paraneoplastic causes, through organ system failures, postcardiorespiratory arrest, to postoperative delirium. The issue is supplemented by tables of relevant clinical correlations, graphs, Venn diagrams, and the use of mathematical modeling used to explain how defects in the neuronal interplay might generate the EEG patterns seen in encephalopathy. We hope that this assembly will act as a springboard for further discussion and investigation into the EEG underpinnings, clinical correlations, diagnosis. and prognostication of these common and morbid disturbances of brain function.

Agricultural management affects evolutionary processes in a migratory songbird

USGS Publications Warehouse

Perlut, N.G.; Freeman-Gallant, C. R.; Strong, A.M.; Donovan, T.M.; Kilpatrick, C.W.; Zalik, N.J.

2008-01-01

Hay harvests have detrimental ecological effects on breeding songbirds, as harvesting results in nest failure. Importantly, whether harvesting also affects evolutionary processes is not known. We explored how hay harvest affected social and genetic mating patterns, and thus, the overall opportunity for sexual selection and evolutionary processes for a ground-nesting songbird, the Savannah sparrow (Passerculus sandwichensis). On an unharvested field, 55% of females were in polygynous associations, and social polygyny was associated with greater rates of extra-pair paternity (EPP). In this treatment, synchrony explained variation in EPP rates, as broods by more synchronous females had more EPP than broods by asynchronous females. In contrast, on a harvested field, simultaneous nest failure caused by haying dramatically decreased the overall incidence of EPP by increasing the occurrence of social monogamy and, apparently, the ability of polygynous males to maintain paternity in their own nests. Despite increased social and genetic monogamy, these haying-mediated changes in mating systems resulted in greater than twofold increase in the opportunity for sexual selection. This effect arose, in part, from a 30% increase in the variance associated with within-pair fertilization success, relative to the unharvested field. This effect was caused by a notable increase (+110%) in variance associated with the quality of social mates following simultaneous nest failure. Because up to 40% of regional habitat is harvested by early June, these data may demonstrate a strong population-level effect on mating systems, sexual selection, and consequently, evolutionary processes. ?? 2008 The Authors.

An improved method for characterizing photoresist lithographic and defectivity performance for sub-20nm node lithography

NASA Astrophysics Data System (ADS)

Amblard, Gilles; Purdy, Sara; Cooper, Ryan; Hockaday, Marjory

2016-03-01

The overall quality and processing capability of lithographic materials are critical for ensuring high device yield and performance at sub-20nm technology nodes in a high volume manufacturing environment. Insufficient process margin and high line width roughness (LWR) cause poor manufacturing control, while high defectivity causes product failures. In this paper, we focus on the most critical layer of a sub-20nm technology node LSI device, and present an improved method for characterizing both lithographic and post-patterning defectivity performance of state-of-the-art immersion photoresists. Multiple formulations from different suppliers were used and compared. Photoresists were tested under various process conditions, and multiple lithographic metrics were investigated (depth of focus, exposure dose latitude, line width roughness, etc.). Results were analyzed and combined using an innovative approach based on advanced software, providing clearer results than previously available. This increased detail enables more accurate performance comparisons among the different photoresists. Post-patterning defectivity was also quantified, with defects reviewed and classified using state-of-the-art inspection tools. Correlations were established between the lithographic and post-patterning defectivity performances for each material, and overall ranking was established among the photoresists, enabling the selection of the best performer for implementation in a high volume manufacturing environment.

Breathing pattern and chest wall volumes during exercise in patients with cystic fibrosis, pulmonary fibrosis and COPD before and after lung transplantation.

PubMed

Wilkens, H; Weingard, B; Lo Mauro, A; Schena, E; Pedotti, A; Sybrecht, G W; Aliverti, A

2010-09-01

Pulmonary fibrosis (PF), cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) often cause chronic respiratory failure (CRF). In order to investigate if there are different patterns of adaptation of the ventilatory pump in CRF, in three groups of lung transplant candidates with PF (n=9, forced expiratory volume in 1 s (FEV(1))=37+/-3% predicted, forced vital capacity (FVC)=32+/-2% predicted), CF (n=9, FEV(1)=22+/-3% predicted, FVC=30+/-3% predicted) and COPD (n=21, FEV(1)=21+/-1% predicted, FVC=46+/-2% predicted), 10 healthy controls and 16 transplanted patients, total and compartmental chest wall volumes were measured by opto-electronic plethysmography during rest and exercise. Three different breathing patterns were found during CRF in PF, CF and COPD. Patients with COPD were characterised by a reduced duty cycle at rest and maximal exercise (34+/-1%, p<0.001), while patients with PF and CF showed an increased breathing frequency (49+/-6 and 34+/-2/min, respectively) and decreased tidal volume (0.75+/-0.10 and 0.79+/-0.07 litres) (p<0.05). During exercise, end-expiratory chest wall and rib cage volumes increased significantly in patients with COPD and CF but not in those with PF. End-inspiratory volumes did not increase in CF and PF. The breathing pattern of transplanted patients was similar to that of healthy controls. There are three distinct patterns of CRF in patients with PF, CF and COPD adopted by the ventilatory pump to cope with the underlying lung disease that may explain why patients with PF and CF are prone to respiratory failure earlier than patients with COPD. After lung transplantation the chronic adaptations of the ventilatory pattern to advanced lung diseases are reversible and indicate that the main contributing factor is the lung itself rather than systemic effects of the disease.

A Case Study on the Strata Movement Mechanism and Surface Deformation Regulation in Chengchao Underground Iron Mine

NASA Astrophysics Data System (ADS)

Cheng, Guanwen; Chen, Congxin; Ma, Tianhui; Liu, Hongyuan; Tang, Chunan

2017-04-01

The regular pattern of surface deformation and the mechanism of underground strata movement, especially in iron mines constructed with the block caving method, have a great influence on infrastructure on the surface, so they are an important topic for research. Based on the engineering geology conditions and the surface deformation and fracture features in Chengchao Iron Mine, the mechanism of strata movement and the regular pattern of surface deformation in the footwall were studied by the geomechanical method, and the following conclusions can be drawn: I. The surface deformation process is divided into two stages over time, i.e., the chimney caving development stage and the post-chimney deformation stage. Currently, the surface deformation in Chengchao Iron Mine is at the post-chimney deformation stage. II. At the post-chimney deformation stage, the surface deformation and geological hazards in Chengchao Iron Mine are primarily controlled by the NWW-trending joints, with the phenomenon of toppling deformation and failure on the surface. Based on the surface deformation characteristics in Chengchao Iron Mine, the surface deformation area can be divided into the following four zones: the fracture extension zone, the fracture closure zone, the fracture formation zone and the deformation accumulation zone. The zones on the surface can be determined by the surface deformation characteristics. III. The cantilever beams near the chimney caving area, caused by the NWW-trending joints, have been subjected to toppling failure. This causes the different deformation and failure mechanisms in different locations of the deep rock mass. The deep rock can be divided into four zones, i.e., the fracture zone, fracture transition zone, deformation zone and undisturbed zone, according to the different deformation and failure mechanisms. The zones in the deep rock are the reason for the zones on the surface, so they can be determined by the zones on the surface. Through these findings, the degree of damage to the infrastructure in different locations can be determined based on the surface deformation zones. As the mining continues deeper, the development regulation of the zones on the surface and in deep rock mass can be further studied based on the zones in the deep rock.

A study on mass hysteria (monkey men?) victims in East Delhi.

PubMed

Verma, S K; Srivastava, D K

2003-08-01

During the summer month of May 2001 East Delhi came in grip of an outbreak of mass hysteria. Initial reports alleged that some monkey like creature attacked and caused injuries among number of persons. A medical board was set up to examine and find out the cause of injuries in the victims of the outbreak as a part exercise to apprehend the culprit. The study describes the sociodemographic pattern and injuries observed in these cases. Majority of victims were adult males, belonging to low socioeconomic strata and having low educational level. The incidents occurred mainly during night at the time of power failure. The type, distribution and characteristic of the injuries suggested of their accidental nature. The paper also discusses the role of forensic experts and press in such outbreak.

Comparative study of LDR (Manchester system) and HDR image-guided conformal brachytherapy of cervical cancer: patterns of failure, late complications, and survival.

PubMed

Narayan, Kailash; van Dyk, Sylvia; Bernshaw, David; Rajasooriyar, Chrishanthi; Kondalsamy-Chennakesavan, Srinivas

2009-08-01

To compare patterns of failure, late toxicities, and survival in locally advanced cervical cancer patients treated by either low-dose-rate (LDR) or conformal high-dose-rate (HDRc) brachytherapy as a part of curative radiotherapy. A retrospective comparative study of 217 advanced cervix cancer patients was conducted; 90 of these patients received LDR and 127 received HDRc brachytherapy. All patients were staged using International Federation of Gynecology and Obstetrics (FIGO) rules, had pretreatment magnetic resonance imaging (MRI), and were treated with concurrent cisplatin chemoradiotherapy. Both groups matched for FIGO stage, MRI tumor volume, and uterine invasion status. Local and pelvic failures were similar 12-13% and 14% both in both groups. Abdominal and systemic failures in LDR group were 21% and 24%, whereas corresponding failures in HDRc group were 20% and 24%. Sixty-eight percent (87/127) of patients treated by HDRc remained asymptomatic, whereas 42% (38/90) of patients were asymptomatic from the bowel and bladder symptoms after treatment with LDR. The 5-year OS rate was 60% (SE = 4%). The 5-year failure-free survival rate was 55% (SE = 3%). There was no significant difference between the groups. Image-guided HDRc planning led to a large decrease in late radiation effects in patients treated by HDRc. Patterns of failure and survival were similar in patients treated either by LDR or HDRc.

Do Learning Difficulties Differentiate Elementary Teachers' Attributional Patterns for Students' Academic Failure? A Comparison between Greek Regular and Special Education Teachers

ERIC Educational Resources Information Center

Vlachou, Anastasia; Eleftheriadou, Dimitra; Metallidou, Panayiota

2014-01-01

This study aimed to (a) investigate whether the presence of learning difficulties (LD) in primary school children differentiates Greek teachers' attributional patterns, emotional responses, expectations and evaluative feedback for the children's academic failures and (b) to examine possible differences between regular and special education…

Sleep in heart failure.

PubMed

Naughton, Matthew T; Lorenzi-Filho, Geraldo

2009-01-01

Sleep plays a large role in patients with heart failure. In normal subjects, sleep is usually in a supine position with reduced sympathetic drive, elevated vagal tone and as such a relatively lower cardiac output and minute ventilation, allowing for recuperation. Patients with heart failure may not experience the same degree of autonomic activity change and the supine position may place a large strain on the pulmonary system. More than half of all heart failure patients have one of two types of sleep apnea: either obstructive or central sleep apnea. Some patients have both types. Obstructive sleep apnea is likely to be a cause of heart failure due to large negative intrathoracic pressures, apnea related hypoxemia and hypercapnia, terminated by an arousal and surge in systemic blood pressure associated with endothelial damage and resultant premature atherosclerosis. Reversal of obstructive sleep apnea improves blood pressure, systolic contraction and autonomic dysfunction however mortality studies are lacking. Central sleep apnea with Cheyne Stokes pattern of respiration (CSA-CSR) occurs as a result of increased central controller (brainstem driving ventilation) and plant (ventilation driving CO2) gain in the setting of a delayed feed back (i.e., low cardiac output). It is thought this type of apnea is a result of moderately to severely impaired cardiac function and is possibly indicative of high mortality. Treatment of CSA-CSR is best undertaken by treating the underlying cardiac condition which may include with medications, pacemakers, transplantation or continuous positive airway pressure (CPAP). In such patients CPAP exerts unique effects to assist cardiac function and reduce pulmonary edema. Whether CPAP improves survival in this heart failure population remains to be determined.

Pharmacological management of chronic heart failure in adults: a review of the literature.

PubMed

Auty, Richard

2004-03-01

Heart failure is a common, life threatening condition encountered in patients of all ages and in all clinical settings. It may be due to any of a wide variety of causes - in Malawi, cardiomyopathies, hypertension and rheumatic heart disease are probably the commonest causes of heart failure. In more affluent societies, ischaemic heart disease is an important factor. Chronic heart failure (CHF) causes significant morbidity: it reduces exercise capacity, interferes with sleep and produces unsightly and uncomfortable oedema. The syndrome also carries substantial mortatity, worse than that of many malignant tumours: 20 -30% of patients with mild or moderately severe heart failure will die every year if left untreated. The life expectancy of a patient with untreated severe heart failure is only about 6 months. Table 1 explains the symptomatic classification of the severity of heart failure. Objective measurements of cardiac function, such as Left Ventricular Ejection Fraction (LYEF) or chamber filling pressures, correlate poorly with symptoms and New York Heart Association (NYHA) classification. Many of the problems experienced by a patient with heart failure are due to a 'vicious circle' of events in which pathophysiological responses to the falling cardiac output cause further deterioration in cardiac function over time. These responses include ventricular remodeling, neurohumoural activation (increased sympathetic activity; increased atrial natriuretic peptide; increased angiotensin II), increased activity of the renin-angiotensin-aldosterone system (RAAS) causing fluid retention, vasoconstriction and sodium retention. [Table: see text].

Field epidemiology to manage BRD risk in beef cattle production systems.

PubMed

Smith, David R

2014-12-01

Field disease investigations can help to identify patterns of disease that lead to causal hypotheses and, hopefully, effective disease risk management strategies. The most common way of doing this would be to characterize the outbreak by subject, time, and space. One of the perplexing animal health problems on some beef cattle ranches is the occurrence of pneumonia in calves prior to weaning in conditions of little stress and relative isolation. Field investigation of outbreaks of pneumonia in ranch calves prior to weaning has revealed patterns of sporadic illness in calves less than 30 days of age, and rapidly occurring outbreaks in calves 90-150 days of age. We speculate that the causes of these two patterns may be failure of passive transfer resulting in more sporadic cases in very young calves, or a large proportion of the population losing maternal antibody protection (i.e. losing herd immunity) resulting in rapid and widespread onset of pneumonia in older calves.

Project #153M: Guidance for Assessing the Remaining Strength of Corroded Pipelines

DOT National Transportation Integrated Search

2010-04-01

Incident statistics have consistently shown that corrosion is the primary cause of pipeline failures in liquid pipelines, and is the second largest cause of failures in natural gas transmission pipelines and distribution piping. Corrosion can cause m...

36 CFR 223.137 - Causes for debarment.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., fire prevention, and the disposal of slash; (2) Protection of soil, water, wildlife, range, cultural, and timber resources and protection of improvements when such failure causes significant environmental, resource, or improvements damage; (3) Removal of designated timber when such failure causes substantial...

Common Cause Failure Modeling

NASA Technical Reports Server (NTRS)

Hark, Frank; Britton, Paul; Ring, Rob; Novack, Steven D.

2016-01-01

Common Cause Failures (CCFs) are a known and documented phenomenon that defeats system redundancy. CCFS are a set of dependent type of failures that can be caused by: system environments; manufacturing; transportation; storage; maintenance; and assembly, as examples. Since there are many factors that contribute to CCFs, the effects can be reduced, but they are difficult to eliminate entirely. Furthermore, failure databases sometimes fail to differentiate between independent and CCF (dependent) failure and data is limited, especially for launch vehicles. The Probabilistic Risk Assessment (PRA) of NASA's Safety and Mission Assurance Directorate at Marshal Space Flight Center (MFSC) is using generic data from the Nuclear Regulatory Commission's database of common cause failures at nuclear power plants to estimate CCF due to the lack of a more appropriate data source. There remains uncertainty in the actual magnitude of the common cause risk estimates for different systems at this stage of the design. Given the limited data about launch vehicle CCF and that launch vehicles are a highly redundant system by design, it is important to make design decisions to account for a range of values for independent and CCFs. When investigating the design of the one-out-of-two component redundant system for launch vehicles, a response surface was constructed to represent the impact of the independent failure rate versus a common cause beta factor effect on a system's failure probability. This presentation will define a CCF and review estimation calculations. It gives a summary of reduction methodologies and a review of examples of historical CCFs. Finally, it presents the response surface and discusses the results of the different CCFs on the reliability of a one-out-of-two system.

Common Cause Failure Modeling

NASA Technical Reports Server (NTRS)

Hark, Frank; Britton, Paul; Ring, Rob; Novack, Steven D.

2015-01-01

Common Cause Failures (CCFs) are a known and documented phenomenon that defeats system redundancy. CCFS are a set of dependent type of failures that can be caused by: system environments; manufacturing; transportation; storage; maintenance; and assembly, as examples. Since there are many factors that contribute to CCFs, the effects can be reduced, but they are difficult to eliminate entirely. Furthermore, failure databases sometimes fail to differentiate between independent and CCF (dependent) failure and data is limited, especially for launch vehicles. The Probabilistic Risk Assessment (PRA) of NASA's Safety and Mission Assurance Directorate at Marshall Space Flight Center (MFSC) is using generic data from the Nuclear Regulatory Commission's database of common cause failures at nuclear power plants to estimate CCF due to the lack of a more appropriate data source. There remains uncertainty in the actual magnitude of the common cause risk estimates for different systems at this stage of the design. Given the limited data about launch vehicle CCF and that launch vehicles are a highly redundant system by design, it is important to make design decisions to account for a range of values for independent and CCFs. When investigating the design of the one-out-of-two component redundant system for launch vehicles, a response surface was constructed to represent the impact of the independent failure rate versus a common cause beta factor effect on a system's failure probability. This presentation will define a CCF and review estimation calculations. It gives a summary of reduction methodologies and a review of examples of historical CCFs. Finally, it presents the response surface and discusses the results of the different CCFs on the reliability of a one-out-of-two system.

Incidence and predictors of 6 months mortality after an acute heart failure event in rural Uganda: The Mbarara Heart Failure Registry (MAHFER).

PubMed

Abeya, Fardous Charles; Lumori, Boniface Amanee Elias; Akello, Suzan Joan; Annex, Brian H; Buda, Andrew J; Okello, Samson

2018-03-29

We sought to estimate the incidence and predictors of all-cause mortality 6 months after heart failure hospitalization in Uganda. Mbarara Heart Failure Registry is a cohort of patients hospitalized with a clinical diagnosis of heart failure at Mbarara Regional Referral Hospital, Uganda. We measured serum electrolytes, cardiac markers, and echocardiograms. All participants were followed until death or end of 6 months. We used Fine and Gray models to estimate the incidence and predictors all-cause mortality. A total of 215 participants were enrolled, 141 (66%) were women, and mean age 53 (standard deviation 22) years. Nineteen (9%) had diabetes, 40 (19%) had HIV, and 119 (55%) had hypertension. The overall incidence of all-cause mortality was 3.58 (95% CI 2.92, 4.38) per 1000 person-days. Men had higher incidence of death compared to women (4.02 vs 3.37 per 1000 person-days). The incidence of all-cause mortality during hospitalization was almost twice that of in the community (27.5 vs 14.77 per 1000 person-days). In adjusted analysis, increasing age, NYHA class IV, decreasing renal function, smoking, each unit increase in serum levels of Potassium, BNP, and Creatine kinase-MB predicted increased incidence of 6 months all-cause death whereas taking beta-blockers and having an index admission on a weekend compared to a week day predicted survival. There is a high incidence of all-cause mortality occurring in-hospital among patients hospitalized with heart failure in rural Uganda. Heart failure directed therapies should be instituted to curb heart failure-related mortality. Copyright © 2017 Elsevier B.V. All rights reserved.

An Update on Drug-induced Liver Injury.

PubMed

Devarbhavi, Harshad

2012-09-01

Idiosyncratic drug-induced liver injury (DILI) is an important cause of morbidity and mortality following drugs taken in therapeutic doses. Hepatotoxicity is a leading cause of attrition in drug development, or withdrawal or restricted use after marketing. No age is exempt although adults and the elderly are at increased risk. DILI spans the entire spectrum ranging from asymptomatic elevation in transaminases to severe disease such as acute hepatitis leading to acute liver failure. The liver specific Roussel Uclaf Causality Assessment Method is the most validated and extensively used for determining the likelihood that an implicated drug caused DILI. Asymptomatic elevation in liver tests must be differentiated from adaptation. Drugs producing DILI have a signature pattern although no single pattern is characteristic. Antimicrobial and central nervous system agents including antiepileptic drugs are the leading causes of DILI worldwide. In the absence of a diagnostic test or a biomarker, the diagnosis rests on the evidence of absence of competing causes such as acute viral hepatitis, autoimmune hepatitis and others. Recent studies show that antituberculosis drugs given for active or latent disease are still a major cause of drug-induced liver injury in India and the West respectively. Presence of jaundice signifies a severe disease and entails a worse outcome. The pathogenesis is unclear and is due to a mix of host, drug metabolite and environmental factors. Research has evolved from incriminating candidate genes to genome wide analysis studies. Immediate cessation of the drug is key to prevent or minimize progressive damage. Treatment is largely supportive. N-acetylcysteine is the antidote for paracetamol toxicity. Carnitine has been tried in valproate injury whereas steroids and ursodeoxycholic acid may be used in DILI associated with hypersensitivity or cholestatic features respectively. This article provides an overview of the epidemiology, the patterns of hepatotoxicity, the pathogenesis and associated risk factors besides its clinical management.

Acute kidney failure

MedlinePlus

Kidney failure; Renal failure; Renal failure - acute; ARF; Kidney injury - acute ... There are many possible causes of kidney damage. They include: ... cholesterol (cholesterol emboli) Decreased blood flow due to very ...

Skin-Stiffener Debond Prediction Based on Computational Fracture Analysis

NASA Technical Reports Server (NTRS)

Krueger, Ronald; Minguet, Pierre J.; Gates, Tom (Technical Monitor)

2005-01-01

Interlaminar fracture mechanics has proven useful for characterizing the onset of delaminations in composites and has been used with limited success primarily to investigate onset in fracture toughness specimens and laboratory size coupon type specimens. Future acceptance of the methodology by industry and certification authorities however, requires the successful demonstration of the methodology on structural level. For this purpose a panel was selected that is reinforced with stringers. Shear loading causes the panel to buckle and the resulting out-of-plane deformations initiate skin/stringer separation at the location of an embedded defect. For finite element analysis, the panel and surrounding load fixture were modeled with shell elements. A small section of the stringer foot and the panel in the vicinity of the embedded defect were modeled with a local 3D solid model. Across the width of the stringer foot the mixed-mode strain energy release rates were calculated using the virtual crack closure technique. A failure index was calculated by correlating the results with the mixed-mode failure criterion of the graphite/epoxy material. For small applied loads the failure index is well below one across the entire width. With increasing load the failure index approaches one first near the edge of the stringer foot from which delamination is expected to grow. With increasing delamination lengths the buckling pattern of the panel changes and the failure index increases which suggests that rapid delamination growth from the initial defect is to be expected.

Biochemical defects of mutant nudel alleles causing early developmental arrest or dorsalization of the Drosophila embryo.

PubMed Central

LeMosy, E K; Leclerc, C L; Hashimoto, C

2000-01-01

The nudel gene of Drosophila is maternally required both for structural integrity of the egg and for dorsoventral patterning of the embryo. It encodes a structurally modular protein that is secreted by ovarian follicle cells. Genetic and molecular studies have suggested that the Nudel protein is also functionally modular, with a serine protease domain that is specifically required for ventral development. Here we describe biochemical and immunolocalization studies that provide insight into the molecular basis for the distinct phenotypes produced by nudel mutations and for the interactions between these alleles. Mutations causing loss of embryonic dorsoventral polarity result in a failure to activate the protease domain of Nudel. Our analyses support previous findings that catalytic activity of the protease domain is required for dorsoventral patterning and that the Nudel protease is auto-activated and reveal an important role for a region adjacent to the protease domain in Nudel protease function. Mutations causing egg fragility and early embryonic arrest result in a significant decrease in extracellular Nudel protein, due to defects in post-translational processing, stability, or secretion. On the basis of these and other studies of serine proteases, we suggest potential mechanisms for the complementary and antagonistic interactions between the nudel alleles. PMID:10628985

Review of liver injury associated with dietary supplements.

PubMed

Stickel, Felix; Kessebohm, Kerstin; Weimann, Rosemarie; Seitz, Helmut K

2011-05-01

Dietary supplements (DS) are easily available and increasingly used, and adverse hepatic reactions have been reported following their intake. To critically review the literature on liver injury because of DSs, delineating patterns and mechanisms of injury and to increase the awareness towards this cause of acute and chronic liver damage. Studies and case reports on liver injury specifically because of DSs published between 1990 and 2010 were searched in the PubMed and EMBASE data bases using the terms 'dietary/nutritional supplements', 'adverse hepatic reactions', 'liver injury'; 'hepatitis', 'liver failure', 'vitamin A' and 'retinoids', and reviewed for yet unidentified publications. Significant liver injury was reported after intake of Herbalife and Hydroxycut products, tea extracts from Camellia sinensis, products containing usnic acid and high contents of vitamin A, anabolic steroids and others. No uniform pattern of hepatotoxicity has been identified and severity may range from asymptomatic elevations of serum liver enzymes to hepatic failure and death. Exact estimates on how frequent adverse hepatic reactions occur as a result of DSs cannot be provided. Liver injury from DSs mimicking other liver diseases is increasingly recognized. Measures to reduce risk include tighter regulation of their production and distribution and increased awareness of users and professionals of the potential risks. © 2011 John Wiley & Sons A/S.

Fracture mechanisms in multilayer phosphorene assemblies: from brittle to ductile.

PubMed

Liu, Ning; Hong, Jiawang; Zeng, Xiaowei; Pidaparti, Ramana; Wang, Xianqiao

2017-05-24

The outstanding mechanical performance of nacre has stimulated numerous studies on the design of artificial nacres. Phosphorene, a new two-dimensional (2D) material, has a crystalline in-plane structure and non-bonded interaction between adjacent flakes. Therefore, multi-layer phosphorene assemblies (MLPs), in which phosphorene flakes are piled up in a staggered manner, may exhibit outstanding mechanical performance, especially exceptional toughness. Therefore, molecular dynamics simulations are performed to study the dependence of the mechanical properties on the overlap distance between adjacent phosphorene layers and the number of phosphorene flakes per layer. The results indicate that when the flake number is equal to 1, a transition of fracture patterns is observed by increasing the overlap distance, from a ductile failure controlled by interfacial friction to a brittle failure dominated by the breakage of covalent bonds inside phosphorene flakes. Moreover, the failure pattern can be tuned by changing the number of flakes in each phosphorene layer. The results imply that the ultimate strength follows a power law with the exponent -0.5 in terms of the flake number, which is in good agreement with our analytical model. Furthermore, the flake number in each phosphorene layer is optimized as 2 when the temperature is 1 K in order to potentially achieve both high toughness and strength. Moreover, our results regarding the relations between mechanical performance and overlap distance can be explained well using a shear-lag model. However, it should be pointed out that increasing the temperature of MLPs could cause the transition of fracture patterns from ductile to brittle. Therefore, the optimal flake number depends heavily on temperature to achieve both its outstanding strength and toughness. Overall, our findings unveil the fundamental mechanism at the nanoscale for MLPs as well as provide a method to design phosphorene-based structures with targeted properties via tunable overlap distance and flake number in phosphorene layers.

Analysis of rural intersection accidents caused by stop sign violation and failure to yield the right-of-way

DOT National Transportation Integrated Search

2000-09-01

The objectives of this study were to (1) identify the factors that contribute to accidents caused by failure to stop and failure to yield the right-of-way at rural two-way stop-controlled intersections on the state highway system, and (2) determine w...

16 CFR § 1207.5 - Design.

Code of Federal Regulations, 2013 CFR

2013-01-01

... installed swimming pool slide shall be such that no structural failures of any component part shall cause failures of any other component part of the slide as described in the performance tests in paragraphs (d)(4... number and placement of such fasteners shall not cause a failure of the tread under the ladder loading...

Failure of azithromycin 2.0 g in the treatment of gonococcal urethritis caused by high-level resistance in California.

PubMed

Gose, Severin O; Soge, Olusegun O; Beebe, James L; Nguyen, Duylinh; Stoltey, Juliet E; Bauer, Heidi M

2015-05-01

We report a treatment failure to azithromycin 2.0 g caused by a urethral Neisseria gonorrhoeae isolate with high-level azithromycin resistance in California. This report describes the epidemiological case investigation and phenotypic and genetic characterization of the treatment failure isolate.

Attributional processes in the learned helplessness paradigm: behavioral effects of global attributions.

PubMed

Mikulincer, M

1986-12-01

Following the learned helplessness paradigm, I assessed in this study the effects of global and specific attributions for failure on the generalization of performance deficits in a dissimilar situation. Helplessness training consisted of experience with noncontingent failures on four cognitive discrimination problems attributed to either global or specific causes. Experiment 1 found that performance in a dissimilar situation was impaired following exposure to globally attributed failure. Experiment 2 examined the behavioral effects of the interaction between stable and global attributions of failure. Exposure to unsolvable problems resulted in reduced performance in a dissimilar situation only when failure was attributed to global and stable causes. Finally, Experiment 3 found that learned helplessness deficits were a product of the interaction of global and internal attribution. Performance deficits following unsolvable problems were recorded when failure was attributed to global and internal causes. Results were discussed in terms of the reformulated learned helplessness model.

Performance Concern, Contingent Self-Worth, and Responses to Repeated Achievement Failure in Second Graders

ERIC Educational Resources Information Center

Smiley, Patricia A.; Coulson, Sheri L.; Greene, Joelle K.; Bono, Katherine L.

2010-01-01

Individual differences in emotion, cognitions, and task choice following achievement failure are found among four- to seven-year-olds. However, neither performance deterioration during failure nor generalization after failure--aspects of the helpless pattern in 10-year-olds--have been reliably demonstrated in this age group. In the present study,…

Failure to Manage Constant Change

ERIC Educational Resources Information Center

McDonald, Ann

2010-01-01

This study examines patterns of system failure (communication, typographic, material, economic, maintenance) and the resulting workarounds in signs that are intended to communicate frequently changing information in the built environment. The observed failures and workarounds in the communication of ephemeral data and the accompanying narratives…

Chaos emerging in soil failure patterns observed during tillage: Normalized deterministic nonlinear prediction (NDNP) and its application.

PubMed

Sakai, Kenshi; Upadhyaya, Shrinivasa K; Andrade-Sanchez, Pedro; Sviridova, Nina V

2017-03-01

Real-world processes are often combinations of deterministic and stochastic processes. Soil failure observed during farm tillage is one example of this phenomenon. In this paper, we investigated the nonlinear features of soil failure patterns in a farm tillage process. We demonstrate emerging determinism in soil failure patterns from stochastic processes under specific soil conditions. We normalized the deterministic nonlinear prediction considering autocorrelation and propose it as a robust way of extracting a nonlinear dynamical system from noise contaminated motion. Soil is a typical granular material. The results obtained here are expected to be applicable to granular materials in general. From a global scale to nano scale, the granular material is featured in seismology, geotechnology, soil mechanics, and particle technology. The results and discussions presented here are applicable in these wide research areas. The proposed method and our findings are useful with respect to the application of nonlinear dynamics to investigate complex motions generated from granular materials.

Data processing device test apparatus and method therefor

DOEpatents

Wilcox, Richard Jacob; Mulig, Jason D.; Eppes, David; Bruce, Michael R.; Bruce, Victoria J.; Ring, Rosalinda M.; Cole, Jr., Edward I.; Tangyunyong, Paiboon; Hawkins, Charles F.; Louie, Arnold Y.

2003-04-08

A method and apparatus mechanism for testing data processing devices are implemented. The test mechanism isolates critical paths by correlating a scanning microscope image with a selected speed path failure. A trigger signal having a preselected value is generated at the start of each pattern vector. The sweep of the scanning microscope is controlled by a computer, which also receives and processes the image signals returned from the microscope. The value of the trigger signal is correlated with a set of pattern lines being driven on the DUT. The trigger is either asserted or negated depending the detection of a pattern line failure and the particular line that failed. In response to the detection of the particular speed path failure being characterized, and the trigger signal, the control computer overlays a mask on the image of the device under test (DUT). The overlaid image provides a visual correlation of the failure with the structural elements of the DUT at the level of resolution of the microscope itself.

Effect of multidisciplinary disease management for hospitalized heart failure under a national health insurance programme.

PubMed

Mao, Chun-Tai; Liu, Min-Hui; Hsu, Kuang-Hung; Fu, Tieh-Cheng; Wang, Jong-Shyan; Huang, Yu-Yen; Yang, Ning-I; Wang, Chao-Hung

2015-09-01

Multidisciplinary disease management programmes (MDPs) for heart failure have been shown to be effective in Western countries. However, it is not known whether they improve outcomes in a high population density country with a national health insurance programme. In total, 349 patients hospitalized because of heart failure were randomized into control and MDP groups. All-cause death and re-hospitalization related to heart failure were analyzed. The median follow-up period was approximately 2 years. Mean patient age was 60 years; 31% were women; and 50% of patients had coronary artery disease. MDP was associated with fewer all-cause deaths [hazard ratio (HR) = 0.49, 95% confidence interval (CI) = 0.27-0.91, P = 0.02] and heart failure-related re-hospitalizations (HR = 0.44, 95% CI = 0.25-0.77, P = 0.004). MDP was still associated with better outcomes for all-cause death (HR = 0.53, 95% CI = 0.29-0.98, P = 0.04) and heart failure-related re-hospitalization (HR = 0.46, 95% CI = 0.26-0.81, P = 0.007), after adjusting for age, diuretics, diabetes mellitus, chronic kidney disease, hypertension, sodium, and albumin. However, MDPs' effect on all-cause mortality and heart failure-related re-hospitalization was significantly attenuated after adjusting for angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers or β-blockers. A stratified analysis showed that MDP combined with guideline-based medication had synergistic effects. MDP is effective in lowering all-cause mortality and re-hospitalization rates related to heart failure under a national health insurance programme. MDP synergistically improves the effectiveness of guidelines-based medications for heart failure.

3-Dimensional Root Cause Diagnosis via Co-analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Ziming; Lan, Zhiling; Yu, Li

2012-01-01

With the growth of system size and complexity, reliability has become a major concern for large-scale systems. Upon the occurrence of failure, system administrators typically trace the events in Reliability, Availability, and Serviceability (RAS) logs for root cause diagnosis. However, RAS log only contains limited diagnosis information. Moreover, the manual processing is time-consuming, error-prone, and not scalable. To address the problem, in this paper we present an automated root cause diagnosis mechanism for large-scale HPC systems. Our mechanism examines multiple logs to provide a 3-D fine-grained root cause analysis. Here, 3-D means that our analysis will pinpoint the failure layer,more » the time, and the location of the event that causes the problem. We evaluate our mechanism by means of real logs collected from a production IBM Blue Gene/P system at Oak Ridge National Laboratory. It successfully identifies failure layer information for 219 failures during 23-month period. Furthermore, it effectively identifies the triggering events with time and location information, even when the triggering events occur hundreds of hours before the resulting failures.« less

Bearing failure detection of micro wind turbine via power spectral density analysis for stator current signals spectrum

NASA Astrophysics Data System (ADS)

Mahmood, Faleh H.; Kadhim, Hussein T.; Resen, Ali K.; Shaban, Auday H.

2018-05-01

The failure such as air gap weirdness, rubbing, and scrapping between stator and rotor generator arise unavoidably and may cause extremely terrible results for a wind turbine. Therefore, we should pay more attention to detect and identify its cause-bearing failure in wind turbine to improve the operational reliability. The current paper tends to use of power spectral density analysis method of detecting internal race and external race bearing failure in micro wind turbine by estimation stator current signal of the generator. The failure detector method shows that it is well suited and effective for bearing failure detection.

Patterns of failure after the reduced volume approach for elective nodal irradiation in nasopharyngeal carcinoma.

PubMed

Seol, Ki Ho; Lee, Jeong Eun

2016-03-01

To evaluate the patterns of nodal failure after radiotherapy (RT) with the reduced volume approach for elective neck nodal irradiation (ENI) in nasopharyngeal carcinoma (NPC). Fifty-six NPC patients who underwent definitive chemoradiotherapy with the reduced volume approach for ENI were reviewed. The ENI included retropharyngeal and level II lymph nodes, and only encompassed the echelon inferior to the involved level to eliminate the entire neck irradiation. Patients received either moderate hypofractionated intensity-modulated RT for a total of 72.6 Gy (49.5 Gy to elective nodal areas) or a conventional fractionated three-dimensional conformal RT for a total of 68.4-72 Gy (39.6-45 Gy to elective nodal areas). Patterns of failure, locoregional control, and survival were analyzed. The median follow-up was 38 months (range, 3 to 80 months). The out-of-field nodal failure when omitting ENI was none. Three patients developed neck recurrences (one in-field recurrence in the 72.6 Gy irradiated nodal area and two in the elective irradiated region of 39.6 Gy). Overall disease failure at any site developed in 11 patients (19.6%). Among these, there were six local failures (10.7%), three regional failures (5.4%), and five distant metastases (8.9%). The 3-year locoregional control rate was 87.1%, and the distant failure-free rate was 90.4%; disease-free survival and overall survival at 3 years was 80% and 86.8%, respectively. No patient developed nodal failure in the omitted ENI site. Our investigation has demonstrated that the reduced volume approach for ENI appears to be a safe treatment approach in NPC.

Patterns of failure after the reduced volume approach for elective nodal irradiation in nasopharyngeal carcinoma

PubMed Central

Seol, Ki Ho

2016-01-01

Purpose To evaluate the patterns of nodal failure after radiotherapy (RT) with the reduced volume approach for elective neck nodal irradiation (ENI) in nasopharyngeal carcinoma (NPC). Materials and Methods Fifty-six NPC patients who underwent definitive chemoradiotherapy with the reduced volume approach for ENI were reviewed. The ENI included retropharyngeal and level II lymph nodes, and only encompassed the echelon inferior to the involved level to eliminate the entire neck irradiation. Patients received either moderate hypofractionated intensity-modulated RT for a total of 72.6 Gy (49.5 Gy to elective nodal areas) or a conventional fractionated three-dimensional conformal RT for a total of 68.4–72 Gy (39.6–45 Gy to elective nodal areas). Patterns of failure, locoregional control, and survival were analyzed. Results The median follow-up was 38 months (range, 3 to 80 months). The out-of-field nodal failure when omitting ENI was none. Three patients developed neck recurrences (one in-field recurrence in the 72.6 Gy irradiated nodal area and two in the elective irradiated region of 39.6 Gy). Overall disease failure at any site developed in 11 patients (19.6%). Among these, there were six local failures (10.7%), three regional failures (5.4%), and five distant metastases (8.9%). The 3-year locoregional control rate was 87.1%, and the distant failure-free rate was 90.4%; disease-free survival and overall survival at 3 years was 80% and 86.8%, respectively. Conclusion No patient developed nodal failure in the omitted ENI site. Our investigation has demonstrated that the reduced volume approach for ENI appears to be a safe treatment approach in NPC. PMID:27104162

Quality Issues in Propulsion

NASA Technical Reports Server (NTRS)

McCarty, John P.; Lyles, Garry M.

1997-01-01

Propulsion system quality is defined in this paper as having high reliability, that is, quality is a high probability of within-tolerance performance or operation. Since failures are out-of-tolerance performance, the probability of failures and their occurrence is the difference between high and low quality systems. Failures can be described at 3 levels: the system failure (which is the detectable end of a failure), the failure mode (which is the failure process), and the failure cause (which is the start). Failure causes can be evaluated & classified by type. The results of typing flight history failures shows that most failures are in unrecognized modes and result from human error or noise, i.e. failures are when engineers learn how things really work. Although the study based on US launch vehicles, a sampling of failures from other countries indicates the finding has broad application. The parameters of the design of a propulsion system are not single valued, but have dispersions associated with the manufacturing of parts. Many tests are needed to find failures, if the dispersions are large relative to tolerances, which could contribute to the large number of failures in unrecognized modes.

Respiratory Failure

MedlinePlus

... of oxygen in the blood, it's called hypoxemic (HI-pok-SE-mik) respiratory failure. When respiratory failure ... carbon dioxide in the blood, it's called hypercapnic (HI-per-KAP-nik) respiratory failure. Causes Diseases and ...

Slope failures in municipal solid waste dumps and landfills: a review.

PubMed

Blight, Geoffrey

2008-10-01

Between 1977 and 2005 six large-scale failures of municipal solid waste dumps and landfills have been recorded in the technical literature. The volumes of waste mobilized in the failures varied from 10-12 000 m(3) in a failure that killed nearly 300 people to 1.5 million m(3) in a failure that caused no deaths or injuries. Of the six failures, four occurred in dumps that, as far as is known, had not been subjected to any prior technical investigation of their shear stability. The remaining two failures occurred in engineer-designed landfills, one of which practised leachate recirculation, and the other co-disposed of liquid waste along with solid waste. The paper reviews, describes and analyses the failures and summarizes their causes.

Multiscale processing of loss of metal: a machine learning approach

NASA Astrophysics Data System (ADS)

De Masi, G.; Gentile, M.; Vichi, R.; Bruschi, R.; Gabetta, G.

2017-07-01

Corrosion is one of the principal causes of degradation to failure of marine structures. In practice, localized corrosion is the most dangerous mode of attack and can result in serious failures, in particular in marine flowlines and inter-field lines, arousing serious concerns relatively to environmental impact. The progress in time of internal corrosion, the location along the route and across the pipe section, the development pattern and the depth of the loss of metal are a very complex issue: the most important factors are products characteristics, transport conditions over the operating lifespan, process fluid-dynamics, and pipeline geometrical configuration. Understanding which factors among them play the most important role is a key step to develop a model able to predict with enough accuracy the sections more exposed to risk of failure. Some factors play a crucial role at certain spatial scales while other factors at other scales. The Mutual Information Theory, intimately related to the concept of Shannon Entropy in Information theory, has been applied to detect the most important variables at each scale. Finally, the variables emerged from this analysis at each scale have been integrated in a predicting data driven model sensibly improving its performance.

Mechanical Dyssynchrony Precedes QRS Widening in ATP‐Sensitive K+ Channel–Deficient Dilated Cardiomyopathy

PubMed Central

Yamada, Satsuki; Arrell, D. Kent; Kane, Garvan C.; Nelson, Timothy J.; Perez‐Terzic, Carmen M.; Behfar, Atta; Purushothaman, Saranya; Prinzen, Frits W.; Auricchio, Angelo; Terzic, Andre

2013-01-01

Background Contractile discordance exacerbates cardiac dysfunction, aggravating heart failure outcome. Dissecting the genesis of mechanical dyssynchrony would enable an early diagnosis before advanced disease. Methods and Results High‐resolution speckle‐tracking echocardiography was applied in a knockout murine surrogate of adult‐onset human cardiomyopathy caused by mutations in cardioprotective ATP‐sensitive K+ (KATP) channels. Preceding the established criteria of cardiac dyssynchrony, multiparametric speckle‐based strain resolved nascent erosion of dysfunctional regions within cardiomyopathic ventricles of the KATP channel–null mutant exposed to hemodynamic stress. Not observed in wild‐type counterparts, intraventricular disparity in wall motion, validated by the degree, direction, and delay of myocardial speckle patterns, unmasked the disease substrate from asymptomatic to overt heart failure. Mechanical dyssynchrony preceded widening of the QRS complex and exercise intolerance and progressed into global myocardial discoordination and decompensated cardiac pump function, precipitating a low output syndrome. Conclusions The present study, with the use of high‐resolution imaging, prospectively resolved the origin and extent of intraventricular motion disparity in a KATP channel–knockout model of dilated cardiomyopathy. Mechanical dyssynchrony established as an early marker of cardiomyopathic disease offers novel insight into the pathodynamics of dyssynchronous heart failure. PMID:24308936

Heart failure in South America.

PubMed

Bocchi, Edimar Alcides

2013-05-01

Continued assessment of temporal trends in mortality and epidemiology of specific heart failure in South America is needed to provide a scientific basis for rational allocation of the limited health care resources, and strategies to reduce risk and predict the future burden of heart failure. The epidemiology of heart failure in South America was reviewed. Heart failure is the main cause of hospitalization based on available data from approximately 50% of the South American population. The main etiologies of heart failure are ischemic, idiopathic dilated cardiomyopathy, valvular, hypertensive and chagasic etiologies. In endemic areas, Chagas heart disease may be responsible by 41% of the HF cases. Also, heart failure presents high mortality especially in patients with Chagas etiology. Heart failure and etiologies associated with heart failure may be responsible for 6.3% of causes of deaths. Rheumatic fever is the leading cause of valvular heart disease. However, a tendency to reduction of HF mortality due to Chagas heart disease from 1985 to 2006, and reduction in mortality due to HF from 1999 to 2005 were observed in selected states in Brazil. The findings have important public health implications because the allocation of health care resources, and strategies to reduce risk of heart failure should also consider the control of neglected Chagas disease and rheumatic fever in South American countries.

Heart Failure in South America

PubMed Central

Bocchi, Edimar Alcides

2013-01-01

Continued assessment of temporal trends in mortality and epidemiology of specific heart failure in South America is needed to provide a scientific basis for rational allocation of the limited health care resources, and strategies to reduce risk and predict the future burden of heart failure. The epidemiology of heart failure in South America was reviewed. Heart failure is the main cause of hospitalization based on available data from approximately 50% of the South American population. The main etiologies of heart failure are ischemic, idiopathic dilated cardiomyopathy, valvular, hypertensive and chagasic etiologies. In endemic areas, Chagas heart disease may be responsible by 41% of the HF cases. Also, heart failure presents high mortality especially in patients with Chagas etiology. Heart failure and etiologies associated with heart failure may be responsible for 6.3% of causes of deaths. Rheumatic fever is the leading cause of valvular heart disease. However, a tendency to reduction of HF mortality due to Chagas heart disease from 1985 to 2006, and reduction in mortality due to HF from 1999 to 2005 were observed in selected states in Brazil. The findings have important public health implications because the allocation of health care resources, and strategies to reduce risk of heart failure should also consider the control of neglected Chagas disease and rheumatic fever in South American countries. PMID:23597301

Response of falciparum malaria to different antimalarials in Myanmar.

PubMed Central

Ejov, M. N.; Tun, T.; Aung, S.; Sein, K.

1999-01-01

The purpose of the study was to ascertain the therapeutic efficacy of different treatments for uncomplicated falciparum malaria in the hospitals in Sagaing, northern and eastern Shan, to facilitate updating the existing national antimalarial drug policy. The proposed 14-day trial for monitoring the efficacy of treatments of uncomplicated falciparum malaria is an efficient method for identifying treatment failure patterns at the intermediate level (township hospital) in the Union of Myanmar. Minimal clinical and parasitological data for days 0-14 were required to classify treatment failure and success. Clinical and parasitiological responses on day 3 and days 4-14 were used as clear examples of early and late treatment failure, respectively. Mefloquine is five times more likely to be effective than chloroquine and sulfadoxine pyrimethamine (S-P), whereas chloroquine and S-P treatments have nearly identical failure patterns. The alarming frequency of clinical and parasitological failure (failure rate > 50%) following chloroquine treatment was reported in Sagaing and following S-P treatment in Sagaing and eastern Shan. PMID:10212515

Care management for low-risk patients with heart failure: a randomized, controlled trial.

PubMed

DeBusk, Robert Frank; Miller, Nancy Houston; Parker, Kathleen Marie; Bandura, Albert; Kraemer, Helena Chmura; Cher, Daniel Joseph; West, Jeffrey Alan; Fowler, Michael Bruce; Greenwald, George

2004-10-19

Nurse care management programs for patients with chronic illness have been shown to be safe and effective. To determine whether a telephone-mediated nurse care management program for heart failure reduced the rate of rehospitalization for heart failure and for all causes over a 1-year period. Randomized, controlled trial of usual care with nurse management versus usual care alone in patients hospitalized for heart failure from May 1998 through October 2001. 5 northern California hospitals in a large health maintenance organization. Of 2786 patients screened, 462 met clinical criteria for heart failure and were randomly assigned (228 to intervention and 234 to usual care). Nurse care management provided structured telephone surveillance and treatment for heart failure and coordination of patients' care with primary care physicians. Time to first rehospitalization for heart failure or for any cause and time to a combined end point of first rehospitalization, emergency department visit, or death. At 1 year, half of the patients had been rehospitalized at least once and 11% had died. Only one third of rehospitalizations were for heart failure. The rate of first rehospitalization for heart failure was similar in both groups (proportional hazard, 0.85 [95% CI, 0.46 to 1.57]). The rate of all-cause rehospitalization was similar (proportional hazard, 0.98 [CI, 0.76 to 1.27]). The findings of this study, conducted in a single health care system, may not be generalizable to other health care systems. The overall effect of the intervention was minor. Among patients with heart failure at low risk on the basis of sociodemographic and medical attributes, nurse care management did not statistically significantly reduce rehospitalizations for heart failure or for any cause. Such programs may be less effective for patients at low risk than those at high risk.

Investigation of Possible Wellbore Cement Failures During Hydraulic Fracturing Operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jihoon; Moridis, George

2014-11-01

We model and assess the possibility of shear failure, using the Mohr-Coulomb model ? along the vertical well by employing a rigorous coupled flow-geomechanic analysis. To this end, we vary the values of cohesion between the well casing and the surrounding cement to representing different quality levels of the cementing operation (low cohesion corresponds to low-quality cement and/or incomplete cementing). The simulation results show that there is very little fracturing when the cement is of high quality.. Conversely, incomplete cementing and/or weak cement can causes significant shear failure and the evolution of long fractures/cracks along the vertical well. Specifically, lowmore » cohesion between the well and cemented areas can cause significant shear failure along the well, but the same cohesion as the cemented zone does not cause shear failure. When the hydraulic fracturing pressure is high, low cohesion of the cement can causes fast propagation of shear failure and of the resulting fracture/crack, but a high-quality cement with no weak zones exhibits limited shear failure that is concentrated near the bottom of the vertical part of the well. Thus, high-quality cement and complete cementing along the vertical well appears to be the strongest protection against shear failure of the wellbore cement and, consequently, against contamination hazards to drinking water aquifers during hydraulic fracturing operations.« less

Riser Pattern: Another Determinant of Heart Failure With Preserved Ejection Fraction.

PubMed

Komori, Takahiro; Eguchi, Kazuo; Saito, Toshinobu; Hoshide, Satoshi; Kario, Kazuomi

2016-10-01

Paradoxical increase in blood pressure (BP) during sleep, exceeding those of awake BP, is called the "riser" BP pattern, and known as an abnormal circadian BP rhythm, has been reported to be associated with adverse cardiovascular prognoses. However, the significance of ambulatory BP in heart failure patients with preserved ejection fraction (HFpEF) has never been reported. Here, we tested our hypothesis that abnormal circadian BP rhythm is associated with HFpEF. The authors enrolled 508 patients with hospitalized HF (age 68±13 years; 315 men, 193 women). There were 232 cases of HFpEF and 276 cases of heart failure with reduced ejection fraction (HFrEF). The riser BP pattern was significantly more frequent in the HFpEF (28.9%) group compared with the HFrEF group (19.9%). In a multivariable logistic regression analysis, the riser BP pattern was associated with HFpEF (odds ratio, 1.73; 95% confidence interval, 1.02-2.91; P=.041) independent of the other covariates. In conclusion, the riser BP pattern was associated with HFpEF. ©2016 Wiley Periodicals, Inc.

Heart Failure in Women

PubMed Central

Bozkurt, Biykem; Khalaf, Shaden

2017-01-01

Heart failure is an important cause of morbidity and mortality in women, and they tend to develop it at an older age compared to men. Heart failure with preserved ejection fraction is more common in women than in men and accounts for at least half the cases of heart failure in women. When comparing men and women who have heart failure and a low left ventricular ejection fraction, the women are more symptomatic and have a similarly poor outcome. Overall recommendations for guideline-directed medical therapies show no differences in treatment approaches between men and women. Overall, women are generally underrepresented in clinical trials for heart failure. Further studies are needed to shed light into different mechanisms, causes, and targeted therapies of heart failure in women. PMID:29744014

Why Can't We Bet on ISD Outcomes: ISD ``Form'' as a Predictor of Success

NASA Astrophysics Data System (ADS)

Newman, Mike; Pan, Shan L.; Pan, Gary

The record of failure to deliver large-scale information systems (IS) in a timely fashion that offer value to major commercial and public organizations is legendary. Just looking to critical success factors such as top management support and user involvement in order to understand how to deliver better systems can at best be a partial solution. We seem to overlook an obvious area in our organizations: what can we learn from our information system development (ISD) historical patterns? In order to develop this idea we draw on parallels in sport where current performance and behaviour are believed to be closely linked to historical precedents, or “form”. In that domain, historical patterns are a fallible but valuable predictor of success. Our thesis is that past negative patterns in ISD will tend to repeat themselves without radical intervention. Put another way, failure begets failure. After examining the game of football as an allegory for ISD, we look briefly at two organizations that have experienced a pattern of failure in the IS area in the past but have transformed the way they build IS, moving from negative patterns to successful ones. This chapter ends with suggestions for managers charged with developing new IS as to how they might use their understanding of ISD “form” to improve their chances of success.

The Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS): Unifying Efforts to Inform Practice and Improve Global Outcomes in Peritoneal Dialysis

PubMed Central

Perl, Jeffrey; Davies, Simon J.; Lambie, Mark; Pisoni, Ronald L.; McCullough, Keith; Johnson, David W.; Sloand, James A.; Prichard, Sarah; Kawanishi, Hideki; Tentori, Francesca; Robinson, Bruce M.

2016-01-01

♦ Background: Extending technique survival on peritoneal dialysis (PD) remains a major challenge in optimizing outcomes for PD patients while increasing PD utilization. The primary objective of the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) is to identify modifiable practices associated with improvements in PD technique and patient survival. In collaboration with the International Society for Peritoneal Dialysis (ISPD), PDOPPS seeks to standardize PD-related data definitions and provide a forum for effective international collaborative clinical research in PD. ♦ Methods: The PDOPPS is an international prospective cohort study in Australia, Canada, Japan, the United Kingdom (UK), and the United States (US). Each country is enrolling a random sample of incident and prevalent patients from national samples of 20 to 80 sites with at least 20 patients on PD. Enrolled patients will be followed over an initial 3-year study period. Demographic, comorbidity, and treatment-related variables, and patient-reported data, will be collected over the study course. The primary outcome will be all-cause PD technique failure or death; other outcomes will include cause-specific technique failure, hospitalizations, and patient-reported outcomes. ♦ Results: A high proportion of the targeted number of study sites has been recruited to date in each country. Several ancillary studies have been funded with high momentum toward expansion to new countries and additional participation. ♦ Conclusion: The PDOPPS is the first large, international study to follow PD patients longitudinally to capture clinical practice. With data collected, the study will serve as an invaluable resource and research platform for the international PD community, and provide a means to understand variation in PD practices and outcomes, to identify optimal practices, and to ultimately improve outcomes for PD patients. PMID:26526049

The Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS): Unifying Efforts to Inform Practice and Improve Global Outcomes in Peritoneal Dialysis.

PubMed

Perl, Jeffrey; Davies, Simon J; Lambie, Mark; Pisoni, Ronald L; McCullough, Keith; Johnson, David W; Sloand, James A; Prichard, Sarah; Kawanishi, Hideki; Tentori, Francesca; Robinson, Bruce M

2016-01-01

♦ Extending technique survival on peritoneal dialysis (PD) remains a major challenge in optimizing outcomes for PD patients while increasing PD utilization. The primary objective of the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) is to identify modifiable practices associated with improvements in PD technique and patient survival. In collaboration with the International Society for Peritoneal Dialysis (ISPD), PDOPPS seeks to standardize PD-related data definitions and provide a forum for effective international collaborative clinical research in PD. ♦ The PDOPPS is an international prospective cohort study in Australia, Canada, Japan, the United Kingdom (UK), and the United States (US). Each country is enrolling a random sample of incident and prevalent patients from national samples of 20 to 80 sites with at least 20 patients on PD. Enrolled patients will be followed over an initial 3-year study period. Demographic, comorbidity, and treatment-related variables, and patient-reported data, will be collected over the study course. The primary outcome will be all-cause PD technique failure or death; other outcomes will include cause-specific technique failure, hospitalizations, and patient-reported outcomes. ♦ A high proportion of the targeted number of study sites has been recruited to date in each country. Several ancillary studies have been funded with high momentum toward expansion to new countries and additional participation. ♦ The PDOPPS is the first large, international study to follow PD patients longitudinally to capture clinical practice. With data collected, the study will serve as an invaluable resource and research platform for the international PD community, and provide a means to understand variation in PD practices and outcomes, to identify optimal practices, and to ultimately improve outcomes for PD patients. Copyright © 2016 International Society for Peritoneal Dialysis.

75 FR 51931 - Airworthiness Directives; Dassault-Aviation Model FALCON 7X Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-24

... root cause: A leakage failure mode of Transient Voltage Suppressor (TVS) diodes used on Power... condition is a leakage failure mode of TVS diodes used on PDCU cards or GCU cards in the PPDB, which in... discovery of a common root cause: A leakage failure mode of Transient Voltage Suppressor (TVS) diodes used...

Differences in severity at admission for heart failure between rural and urban patients: the value of adding laboratory results to administrative data.

PubMed

Smith, Mark W; Owens, Pamela L; Andrews, Roxanne M; Steiner, Claudia A; Coffey, Rosanna M; Skinner, Halcyon G; Miyamura, Jill; Popescu, Ioana

2016-04-18

Rural/urban variations in admissions for heart failure may be influenced by severity at hospital presentation and local practice patterns. Laboratory data reflect clinical severity and guide hospital admission decisions and treatment for heart failure, a costly chronic illness and a leading cause of hospitalization among the elderly. Our main objective was to examine the role of laboratory test results in measuring disease severity at the time of admission for inpatients who reside in rural and urban areas. We retrospectively analyzed discharge data on 13,998 hospital discharges for heart failure from three states, Hawai'i, Minnesota, and Virginia. Hospital discharge records from 2008 to 2012 were derived from the State Inpatient Databases of the Healthcare Cost and Utilization Project, and were merged with results of laboratory tests performed on the admission day or up to two days before admission. Regression models evaluated the relationship between clinical severity at admission and patient urban/rural residence. Models were estimated with and without use of laboratory data. Patients residing in rural areas were more likely to have missing laboratory data on admission and less likely to have abnormal or severely abnormal tests. Rural patients were also less likely to be admitted with high levels of severity as measured by the All Patient Refined Diagnosis Related Groups (APR-DRG) severity subclass, derivable from discharge data. Adding laboratory data to discharge data improved model fit. Also, in models without laboratory data, the association between urban compared to rural residence and APR-DRG severity subclass was significant for major and extreme levels of severity (OR 1.22, 95% CI 1.03-1.43 and 1.55, 95% CI 1.26-1.92, respectively). After adding laboratory data, this association became non-significant for major severity and was attenuated for extreme severity (OR 1.12, 95% CI 0.94-1.32 and 1.43, 95% CI 1.15-1.78, respectively). Heart failure patients from rural areas are hospitalized at lower severity levels than their urban counterparts. Laboratory test data provide insight on clinical severity and practice patterns beyond what is available in administrative discharge data.

N-terminal fraction of pro-B-type natriuretic peptide versus clinical risk scores for prognostic stratification in chronic systolic heart failure.

PubMed

Arzilli, Chiara; Aimo, Alberto; Vergaro, Giuseppe; Ripoli, Andrea; Senni, Michele; Emdin, Michele; Passino, Claudio

2018-05-01

Background The Seattle heart failure model or the cardiac and comorbid conditions (3C-HF) scores may help define patient risk in heart failure. Direct comparisons between them or versus N-terminal fraction of pro-B-type natriuretic peptide (NT-proBNP) have never been performed. Methods Data from consecutive patients with stable systolic heart failure and 3C-HF data were examined. A subgroup of patients had the Seattle heart failure model data available. The endpoints were one year all-cause or cardiovascular death. Results The population included 2023 patients, aged 68 ± 12 years, 75% were men. At the one year time-point, 198 deaths were recorded (10%), 124 of them (63%) from cardiovascular causes. While areas under the curve were not significantly different, NT-proBNP displayed better reclassification capability than the 3C-HF score for the prediction of one year all-cause and cardiovascular death. Adding NT-proBNP to the 3C-HF score resulted in a significant improvement in risk prediction. Among patients with Seattle heart failure model data available ( n = 798), the area under the curve values for all-cause and cardiovascular death were similar for the Seattle heart failure model score (0.790 and 0.820), NT-proBNP (0.783 and 0.803), and the 3C-HF score (0.770 and 0.800). The combination of the 3C-HF score and NT-proBNP displayed a similar prognostic performance to the Seattle heart failure model score for both endpoints. Adding NT-proBNP to the Seattle heart failure model score performed better than the Seattle heart failure model alone in terms of reclassification, but not discrimination. Conclusions Among systolic heart failure patients, NT-proBNP levels had better reclassification capability for all-cause and cardiovascular death than the 3C-HF score. The inclusion of NT-proBNP to the 3C-HF and Seattle heart failure model score resulted in significantly better risk stratification.

Differentiating Electromechanical From Non-Electrical Substrates of Mechanical Discoordination to Identify Responders to Cardiac Resynchronization Therapy.

PubMed

Lumens, Joost; Tayal, Bhupendar; Walmsley, John; Delgado-Montero, Antonia; Huntjens, Peter R; Schwartzman, David; Althouse, Andrew D; Delhaas, Tammo; Prinzen, Frits W; Gorcsan, John

2015-09-01

Left ventricular (LV) mechanical discoordination, often referred to as dyssynchrony, is often observed in patients with heart failure regardless of QRS duration. We hypothesized that different myocardial substrates for LV mechanical discoordination exist from (1) electromechanical activation delay, (2) regional differences in contractility, or (3) regional scar and that we could differentiate electromechanical substrates responsive to cardiac resynchronization therapy (CRT) from unresponsive non-electrical substrates. First, we used computer simulations to characterize mechanical discoordination patterns arising from electromechanical and non-electrical substrates and accordingly devise the novel systolic stretch index (SSI), as the sum of posterolateral systolic prestretch and septal systolic rebound stretch. Second, 191 patients with heart failure (QRS duration ≥120 ms; LV ejection fraction ≤35%) had baseline SSI quantified by automated echocardiographic radial strain analysis. Patients with SSI≥9.7% had significantly less heart failure hospitalizations or deaths 2 years after CRT (hazard ratio, 0.32; 95% confidence interval, 0.19-0.53; P<0.001) and less deaths, transplants, or LV assist devices (hazard ratio, 0.28; 95% confidence interval, 0.15-0.55; P<0.001). Furthermore, in a subgroup of 113 patients with intermediate electrocardiographic criteria (QRS duration of 120-149 ms or non-left bundle branch block), SSI≥9.7% was independently associated with significantly less heart failure hospitalizations or deaths (hazard ratio, 0.41; 95% confidence interval, 0.23-0.79; P=0.004) and less deaths, transplants, or LV assist devices (hazard ratio, 0.27; 95% confidence interval, 0.12-0.60; P=0.001). Computer simulations differentiated patterns of LV mechanical discoordination caused by electromechanical substrates responsive to CRT from those related to regional hypocontractility or scar unresponsive to CRT. The novel SSI identified patients who benefited more favorably from CRT, including those with intermediate electrocardiographic criteria, where CRT response is less certain by ECG alone. © 2015 American Heart Association, Inc.

miR-21 is associated with fibrosis and right ventricular failure

PubMed Central

Hu, Dong-Qing; Zhao, Mingming; Blay, Eddie; Sandeep, Nefthi; Ong, Sang-Ging; Jung, Gwanghyun; Kooiker, Kristina B.; Coronado, Michael; Fajardo, Giovanni; Bernstein, Daniel

2017-01-01

Combined pulmonary insufficiency (PI) and stenosis (PS) is a common long-term sequela after repair of many forms of congenital heart disease, causing progressive right ventricular (RV) dilation and failure. Little is known of the mechanisms underlying this combination of preload and afterload stressors. We developed a murine model of PI and PS (PI+PS) to identify clinically relevant pathways and biomarkers of disease progression. Diastolic dysfunction was induced (restrictive RV filling, elevated RV end-diastolic pressures) at 1 month after generation of PI+PS and progressed to systolic dysfunction (decreased RV shortening) by 3 months. RV fibrosis progressed from 1 month (4.4% ± 0.4%) to 3 months (9.2% ± 1%), along with TGF-β signaling and tissue expression of profibrotic miR-21. Although plasma miR-21 was upregulated with diastolic dysfunction, it was downregulated with the onset of systolic dysfunction), correlating with RV fibrosis. Plasma miR-21 in children with PI+PS followed a similar pattern. A model of combined RV volume and pressure overload recapitulates the evolution of RV failure unique to patients with prior RV outflow tract surgery. This progression was characterized by enhanced TGF-β and miR-21 signaling. miR-21 may serve as a plasma biomarker of RV failure, with decreased expression heralding the need for valve replacement. PMID:28469078

Patterns of Success and Failure in the Transition from School to Work in Australia. Research Report.

ERIC Educational Resources Information Center

Lamb, Stephen; McKenzie, Phillip

Patterns of success and failure in the transition from school to work in Australia in the 1980s-1990s were examined by analyzing data from the Australian Youth Survey. Of those studied, 20% found full-time jobs upon leaving school and remained in full-time employment for the next 7 years, 13% obtained apprenticeships or traineeships leading to…

Decreased Mortality With Beta-Blockers in Patients With Heart Failure and Coexisting Atrial Fibrillation: An AF-CHF Substudy.

PubMed

Cadrin-Tourigny, Julia; Shohoudi, Azadeh; Roy, Denis; Talajic, Mario; Tadros, Rafik; Mondésert, Blandine; Dyrda, Katia; Rivard, Léna; Andrade, Jason G; Macle, Laurent; Guerra, Peter G; Thibault, Bernard; Dubuc, Marc; Khairy, Paul

2017-02-01

The impact of beta-blockers on mortality and hospitalizations was assessed in the largest randomized trial of patients with both atrial fibrillation (AF) and heart failure with a reduced ejection fraction (HFrEF): the Atrial Fibrillation-Congestive Heart Failure trial. Although beta-blockers are the cornerstone of therapy for HFrEF, a recent patient-level meta-analysis cast doubt on their efficacy in patients with coexisting AF. From a total of 1,376 subjects randomized in the AF-CHF trial, those without beta-blockers at baseline were propensity matched to a maximum of 2 exposed patients. All absolute standardized differences after matching were ≤10%. Primary analyses respected the intention-to-treat principle. In on-treatment sensitivity analyses, beta-blocker status was modeled as a time-dependent covariate. Baseline characteristics were comparable among the matched cohorts (mean age 70 ± 11 years, 81% male, and mean left ventricular ejection fraction 27 ± 6%). During a median follow-up of 37 months, beta-blockers were associated with significantly lower all-cause mortality (hazard ratio [HR]: 0.721, 95% confidence interval [CI]: 0.549 to 0.945; p = 0.0180) but not hospitalizations (HR: 0.886; 95% CI: 0.715 to 1.100; p = 0.2232). Similar results were obtained in sensitivity analyses that modeled beta-blockers as a time-dependent variable (HR: 0.668 for all-cause mortality; 95% CI: 0.511 to 0.874; p = 0.0032; HR: 0.814 for hospitalizations; 95% CI: 0.653 to 1.014; p = 0.0658). There were no significant interactions between beta-blockers and patterns (i.e., persistent vs. paroxysmal) or burden of AF with respect to mortality or hospitalizations. In propensity-matched analyses, beta-blockers were associated with significantly lower mortality but not hospitalizations in patients with HFrEF and AF, irrespective of the pattern or burden of AF. These results support current evidence-based recommendations for beta-blockers in patients with HFrEF, whether or not they have associated AF. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

A retrospective survey of the causes of bracket- and tube-bonding failures.

PubMed

Roelofs, Tom; Merkens, Nico; Roelofs, Jeroen; Bronkhorst, Ewald; Breuning, Hero

2017-01-01

To investigate the causes of bonding failures of orthodontic brackets and tubes and the effect of premedicating for saliva reduction. Premedication with atropine sulfate was administered randomly. Failure rate of brackets and tubes placed in a group of 158 consecutive patients was evaluated after a mean period of 67 weeks after bonding. The failure rate in the group without atropine sulfate premedication was 2.4%. In the group with premedication, the failure rate was 2.7%. The Cox regression analysis of these groups showed that atropine application did not lead to a reduction in bond failures. Statistically significant differences in the hazard ratio were found for the bracket regions and for the dental assistants who prepared for the bonding procedure. Premedication did not lead to fewer bracket failures. The roles of the dental assistant and patient in preventing failures was relevant. A significantly higher failure rate for orthodontic appliances was found in the posterior regions.

High Technology Systems with Low Technology Failures: Some Experiences with Rockets on Software Quality and Integration

NASA Technical Reports Server (NTRS)

Craig, Larry G.

2010-01-01

This slide presentation reviews three failures of software and how the failures contributed to or caused the failure of a launch or payload insertion into orbit. In order to avoid these systematic failures in the future, failure mitigation strategies are suggested for use.

Applications of crude incidence curves.

PubMed

Korn, E L; Dorey, F J

1992-04-01

Crude incidence curves display the cumulative number of failures of interest as a function of time. With competing causes of failure, they are distinct from cause-specific incidence curves that treat secondary types of failures as censored observations. After briefly reviewing their definition and estimation, we present five applications of crude incidence curves to show their utility in a broad range of studies. In some of these applications it is helpful to model survival-time distributions with use of two different time metameters, for example, time from diagnosis and age of the patient. We describe how one can incorporate published vital statistics into the models when secondary types of failure correspond to common causes of death.

Experimental investigation on the fracture behaviour of black shale by acoustic emission monitoring and CT image analysis during uniaxial compression

NASA Astrophysics Data System (ADS)

Wang, Y.; Li, C. H.; Hu, Y. Z.

2018-04-01

Plenty of mechanical experiments have been done to investigate the deformation and failure characteristics of shale; however, the anisotropic failure mechanism has not been well studied. Here, laboratory Uniaxial Compressive Strength tests on cylindrical shale samples obtained by drilling at different inclinations to bedding plane were performed. The failure behaviours of the shale samples were studied by real-time acoustic emission (AE) monitoring and post-test X-ray computer tomography (CT) analysis. The experimental results suggest that the pronounced bedding planes of shale have a great influence on the mechanical properties and AE patterns. The AE counts and AE cumulative energy release curves clearly demonstrate different morphology, and the `U'-shaped curve relationship between the AE counts, AE cumulative energy release and bedding inclination was first documented. The post-test CT image analysis shows the crack patterns via 2-D image reconstructions, an index of stimulated fracture density is defined to represent the anisotropic failure mode of shale. What is more, the most striking finding is that the AE monitoring results are in good agreement with the CT analysis. The structural difference in the shale sample is the controlling factor resulting in the anisotropy of AE patterns. The pronounced bedding structure in the shale formation results in an anisotropy of elasticity, strength and AE information from which the changes in strength dominate the entire failure pattern of the shale samples.

Patterns of failure and survival in patients with nasopharyngeal carcinoma treated with intensity-modulated radiation therapy in Saudi Arabia.

PubMed

Maklad, Ahmed Marzouk; Bayoumi, Yasser; Senosy Hassan, Mohamed Abdalazez; Elawadi, AbuSaleh A; AlHussain, Hussain; Elyamany, Ashraf; Aldhahri, Saleh F; Al-Qahtani, Khalid Hussain; AlQahtani, Mubarak; Tunio, Mutahir A

2016-01-01

We aimed to investigate the patterns of failure (locoregional and distant metastasis), associated factors, and treatment outcomes in nasopharyngeal carcinoma patients treated with intensity-modulated radiation therapy (IMRT) combined with chemotherapy. From April 2006 to December 2011, 68 nasopharyngeal carcinoma patients were treated with IMRT and chemotherapy at our hospital. Median radiation doses delivered to gross tumor volume and positive neck nodes were 66-70 Gy, 63 Gy to clinical target volume, and 50.4-56 Gy to clinically negative neck. The clinical toxicities, patterns of failures, locoregional control, distant metastasis control, disease-free survival, and overall survival were observed. The median follow-up time was 52.2 months (range: 11-87 months). Epstein-Barr virus infection was positive in 63.2% of patients. Overall disease failure developed in 21 patients, of whom 85.8% belonged to stage III/IV disease. Among these, there were seven locoregional recurrences, three regional recurrences with distant metastases, and eleven distant metastases. The median interval from the date of diagnosis to failure was 26.5 months (range: 16-50 months). Six of ten (60%) locoregional recurrences were treated with reirradiation ± concurrent chemotherapy. The 5-year locoregional control, distant metastasis control, disease-free survival, and overall survival rates of whole cohort were 81.1%, 74.3%, 60.1%, and 73.4%, respectively. Cox regression analyses revealed that neoadjuvant chemotherapy, age, and Epstein-Barr virus were independent predictors for disease-free survival. Neoadjuvant chemotherapy followed by IMRT with or without chemotherapy improves the long-term survival of Saudi patients with nasopharyngeal carcinoma. Distant metastasis was the main pattern of treatment failure. Neoadjuvant chemotherapy, age, and Epstein-Barr virus status before IMRT were important independent prognostic factors.

Periodontitis in Chronic Heart Failure.

PubMed

Fröhlich, Hanna; Herrmann, Kristina; Franke, Jennifer; Karimi, Alamara; Täger, Tobias; Cebola, Rita; Katus, Hugo A; Zugck, Christian; Frankenstein, Lutz

2016-08-01

Periodontal disease has been associated with an increased risk of cardiovascular events. The purpose of our study was to investigate whether a correlation between periodontitis and chronic heart failure exists, as well as the nature of the underlying cause. We enrolled 71 patients (mean age, 54 ± 13 yr; 56 men) who had stable chronic heart failure; all underwent complete cardiologic and dental evaluations. The periodontal screening index was used to quantify the degree of periodontal disease. We compared the findings to those in the general population with use of data from the 4th German Dental Health Survey. Gingivitis, moderate periodontitis, and severe periodontitis were present in 17 (24%), 17 (24%), and 37 (52%) patients, respectively. Severe periodontitis was more prevalent among chronic heart failure patients than in the general population. In contrast, moderate periodontitis was more prevalent in the general population (P <0.00001). The severity of periodontal disease was not associated with the cause of chronic heart failure or the severity of heart failure symptoms. Six-minute walking distance was the only independent predictor of severe periodontitis. Periodontal disease is highly prevalent in chronic heart failure patients regardless of the cause of heart failure. Prospective trials are warranted to clarify the causal relationship between both diseases.

Damage Patterns at the Head-Stem Taper Junction Helps Understand the Mechanisms of Material Loss.

PubMed

Hothi, Harry S; Panagiotopoulos, Andreas C; Whittaker, Robert K; Bills, Paul J; McMillan, Rebecca A; Skinner, John A; Hart, Alister J

2017-01-01

Material loss at the taper junction of metal-on-metal total hip arthroplasties has been implicated in their early failure. The mechanisms of material loss are not fully understood; analysis of the patterns of damage at the taper can help us better understand why material loss occurs at this junction. We mapped the patterns of material loss in a series of 155 metal-on-metal total hip arthroplasties received at our center by scanning the taper surface using a roundness-measuring machine. We examined these material loss maps to develop a 5-tier classification system based on visual differences between different patterns. We correlated these patterns to surgical, implant, and patient factors known to be important for head-stem taper damage. We found that 63 implants had "minimal damage" at the taper (material loss <1 mm 3 ), and the remaining 92 implants could be categorized by 4 distinct patterns of taper material loss. We found that (1) head diameter and (2) time to revision were key significant variables separating the groups. These material loss maps allow us to suggest different mechanisms that dominate the cause of the material loss in each pattern: (1) corrosion, (2) mechanically assisted corrosion, or (3) intraoperative damage or poor size tolerances leading to toggling of trunnion in taper. Copyright © 2016 Elsevier Inc. All rights reserved.

A good time to panic? Premorbid and postmorbid panic disorder in heart failure affects cardiac and psychiatric cause admissions.

PubMed

Tully, Phillip J

2015-04-01

The authors sought to identify characteristics associated with premorbid and postmorbid panic disorder onset in relation to heart failure (HF) onset, and examine the effect on unplanned hospital admissions. In a two-stage screening process, 404 HF patients admitted to three hospitals in South Australia were referred for structured psychiatric interview when any of the following four criteria were met: (a) Patient Health Questionnaire≥10; (b) Generalized Anxiety Disorder Questionnaire≥7); (c) positive response to one-item panic attack screener; (d) or evidence of suicidality. A total of 73 referred HF patients (age 60.6±13.4, 47.9% female) were classified into three groups: premorbid panic disorder (27.4%), postmorbid panic disorder (24.7%), and no panic disorder (47.9%). Postmorbid panic disorder was associated with more psychiatric admissions and longer hospital stay in the 6 months prior to the index psychiatric assessment, and also in the 6 months after the index psychiatric assessment (all p<.05 unadjusted). In sensitivity analysis, years since panic disorder onset were associated with longer cardiac length of stay (β=.34, p=.03). Panic disorder onset in relation to HF diagnosis was associated with discrete patterns of hospital admissions for cardiac and psychiatric causes. © The Royal Australian and New Zealand College of Psychiatrists 2015.

Impaired working memory capacity is not caused by failures of selective attention in schizophrenia.

PubMed

Erickson, Molly A; Hahn, Britta; Leonard, Carly J; Robinson, Benjamin; Gray, Brad; Luck, Steven J; Gold, James

2015-03-01

The cognitive impairments associated with schizophrenia have long been known to involve deficits in working memory (WM) capacity. To date, however, the causes of WM capacity deficits remain unknown. The present study examined selective attention impairments as a putative contributor to observed capacity deficits in this population. To test this hypothesis, we used an experimental paradigm that assesses the role of selective attention in WM encoding and has been shown to involve the prefrontal cortex and the basal ganglia. In experiment 1, participants were required to remember the locations of 3 or 5 target items (red circles). In another condition, 3-target items were accompanied by 2 distractor items (yellow circles), which participants were instructed to ignore. People with schizophrenia (PSZ) exhibited significant impairment in memory for the locations of target items, consistent with reduced WM capacity, but PSZ and healthy control subjects did not differ in their ability to filter the distractors. This pattern was replicated in experiment 2 for distractors that were more salient. Taken together, these results demonstrate that reduced WM capacity in PSZ is not attributable to a failure of filtering irrelevant distractors. © The Author 2014. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

[Mortality due to hypertensive diseases: evidence from the southern border of Mexico in the period 1998-2014].

PubMed

Rivera, José Luis Manzanares

2017-01-01

This article analyzes patterns of mortality due to hypertensive diseases in the southern border of Mexico, as well as the evolution of such mortality in the 1998-2014 period. The emphasis is directed at the causes "Essential (primary) hypertension" (I10X) and "Hypertensive heart disease with heart failure" (I110). Using data from the mortality records of the National Health Information System, two types of analyses were carried out: cross-sectional analysis and time trends. Over the 16 years included in the study, the age-adjusted mortality rates show a clear increase. The findings suggest that the higher presence of indigenous populations is a trait of importance in the determination of the mortality pattern, with the state of Yucatán a case of particular interest. In addition, it is the female population that which exhibits the greatest adverse impact.

Maternal and neonatal outcomes of respiratory failure during pregnancy.

PubMed

Hung, Chen-Yiu; Hu, Han-Chung; Chiu, Li-Chung; Chang, Chih-Hao; Li, Li-Fu; Huang, Chung-Chi; Kao, Chuan-Chi; Cheng, Po-Jen; Kao, Kuo-Chin

2018-05-01

Obstetric patients comprise a limited portion of intensive care unit patients, but they often present with unfamiliar conditions and exhibit the potential for catastrophic deterioration. This study evaluated the maternal and neonatal outcomes of respiratory failure during pregnancy. Information on 71 patients at >25 weeks gestation in the ICU with respiratory failure was recorded between 2009 and 2013. The characteristics and outcomes of mothers and fetuses were determined through a retrospective chart review and evaluated using Student's t test, chi-square test, and Fisher's exact test. The leading causes of respiratory failure were postpartum hemorrhage and severe preeclampsia in the obstetric causes group and pneumonia in the nonobstetric causes group during pregnancy and the peripartum period. The non-obstetric causes group exhibited a higher incidence of acute respiratory distress syndrome and renal replacement therapy as well as requiring more ventilator days. The patients in the obstetric causes group showed significant improvement after delivery in the partial pressure of arterial oxygen to the fraction of inspired oxygen and peak inspiratory pressure decrease. Both groups exhibited high incidences of neonatal respiratory distress syndrome. Neonatal complications resulting from meconium aspiration syndrome (MAS) and sepsis were more common in the non-obstetric causes group; however, neurological development impairment was more common in the obstetric causes group. Obstetric cause was associated with longer ventilator free days and fewer episodes of ARDS after delivery. Neonatal complications resulting from different etiologies of respiratory failure were found to differ. Copyright © 2017. Published by Elsevier B.V.

An observational study of the frequency, severity, and etiology of failures in postoperative care after major elective general surgery.

PubMed

Symons, Nicholas R A; Almoudaris, Alex M; Nagpal, Kamal; Vincent, Charles A; Moorthy, Krishna

2013-01-01

To investigate the nature of process failures in postoperative care, to assess their frequency and preventability, and to explore their relationship to adverse events. Adverse events are common and are frequently caused by failures in the process of care. These processes are often evaluated independently using clinical audit. There is little understanding of process failures in terms of their overall frequency, relative risk, and cumulative effect on the surgical patient. Patients were observed daily from the first postoperative day until discharge by an independent surgeon. Field notes on the circumstances surrounding any nonroutine or atypical event were recorded. Field notes were assessed by 2 surgeons to identify failures in the process of care. Preventability, the degree of harm caused to the patient, and the underlying etiology of process failures were evaluated by 2 independent surgeons. Fifty patients undergoing major elective general surgery were observed for a total of 659 days of postoperative care. A total of 256 process failures were identified, of which 85% were preventable and 51% directly led to patient harm. Process failures occurred in all aspects of care, the most frequent being medication prescribing and administration, management of lines, tubes, and drains, and pain control interventions. Process failures accounted for 57% of all preventable adverse events. Communication failures and delays were the main etiologies, leading to 54% of process failures. Process failures are common in postoperative care, are highly preventable, and frequently cause harm to patients. Interventions to prevent process failures will improve the reliability of surgical postoperative care and have the potential to reduce hospital stay.

Is meiosis a fundamental cause of inviability among sexual and asexual plants and animals?

PubMed

Levitis, Daniel A; Zimmerman, Kolea; Pringle, Anne

2017-08-16

Differences in viability between asexually and sexually generated offspring strongly influence the selective advantage and therefore the prevalence of sexual reproduction (sex). However, no general principle predicts when sexual offspring will be more viable than asexual offspring. We hypothesize that when any kind of reproduction is based on a more complex cellular process, it will encompass more potential failure points, and therefore lower offspring viability. Asexual reproduction (asex) can be simpler than sex, when offspring are generated using only mitosis. However, when asex includes meiosis and meiotic restitution, gamete production is more complex than in sex. We test our hypothesis by comparing the viability of asexual and closely related sexual offspring across a wide range of plants and animals, and demonstrate that meiotic asex does result in lower viability than sex; without meiosis, asex is mechanistically simple and provides higher viability than sex. This phylogenetically robust pattern is supported in 42 of 44 comparisons drawn from diverse plants and animals, and is not explained by the other variables included in our model. Other mechanisms may impact viability, such as effects of reproductive mode on heterozygosity and subsequent viability, but we propose the complexity of cellular processes of reproduction, particularly meiosis, as a fundamental cause of early developmental failure and mortality. Meiosis, the leading cause of inviability in humans, emerges as a likely explanation of offspring inviability among diverse eukaryotes. © 2017 The Author(s).

The Measurement Of Total Joint Loosening By X-Ray Photogrammetry

NASA Astrophysics Data System (ADS)

Lippert, Frederick G.; Veress, Sandor A.; Tiwari, Rama S.; Harrington, Richard M.

1980-07-01

Failure of total joint replacement due to loosening of the composents either between the implant and cement or between the cement and bone is emerging as a late complication with an incidence as high as 20 percent. Loosening may not only cause pain but progressive loss of support for the prosthesis with eventual structural failure. Early diagnosis is important so that revision may be carried when deterioration or pain occurs. No method is currently available which clearly establishes loosening at an early stage except surgical exploration. We have devised a method based on our in vivo photogrammetry studies of patellar tracking patterns using metallic markers placed in bone near both components of the total joint. Stereo x-rays taken with the joint loaded and unloaded are measured for relative motion between the implant and the metallic markers. Laboratory studies using prosthetic hip components mounted in plastic bone have revealed the ability of this method to detect pistoning movements as small as 80 microns. These findings were confirmed by physical measurements.

Nosocomial outbreak of legionellosis in a rehabilitation center. Demonstration of potable water as a source.

PubMed

Nechwatal, R; Ehret, W; Klatte, O J; Zeissler, H J; Prull, A; Lutz, H

1993-01-01

Ten patients from a rehabilitation center were admitted to hospital with serious respiratory infections within ten weeks. An outbreak of Legionnaire's disease was suspected based on the epidemic and atypical manifestation of pneumonia and could be proven microbiologically. Pulmonary and extrapulmonary complications included respiratory failure, lung abscess, transitory renal impairment in five patients and acute renal failure requiring dialysis in one, tetraparesis caused by peripheral neuropathy and acute psychosis. Three patients died despite immediate institution of therapy with erythromycin. Legionella pneumophila serogroup 1 subtype Pontiac was isolated from a bronchial lavage sample of one patient and from the water supply of the rehabilitation center. Monoclonal antibody subtyping and restriction endonuclease analysis were performed on both environmental and patient isolates. Potable water was identified as the source of the outbreak based on identical patterns on restriction endonuclease analysis. Despite thermic and chemical disinfection with chlorination (up to 15 ppm) in the rehabilitation clinic, an eleventh case of Legionnaire's disease was detected 11 months later.

Systemic inflammatory response following acute myocardial infarction

PubMed Central

Fang, Lu; Moore, Xiao-Lei; Dart, Anthony M; Wang, Le-Min

2015-01-01

Acute cardiomyocyte necrosis in the infarcted heart generates damage-associated molecular patterns, activating complement and toll-like receptor/interleukin-1 signaling, and triggering an intense inflammatory response. Inflammasomes also recognize danger signals and mediate sterile inflammatory response following acute myocardial infarction (AMI). Inflammatory response serves to repair the heart, but excessive inflammation leads to adverse left ventricular remodeling and heart failure. In addition to local inflammation, profound systemic inflammation response has been documented in patients with AMI, which includes elevation of circulating inflammatory cytokines, chemokines and cell adhesion molecules, and activation of peripheral leukocytes and platelets. The excessive inflammatory response could be caused by a deregulated immune system. AMI is also associated with bone marrow activation and spleen monocytopoiesis, which sustains a continuous supply of monocytes at the site of inflammation. Accumulating evidence has shown that systemic inflammation aggravates atherosclerosis and markers for systemic inflammation are predictors of adverse clinical outcomes (such as death, recurrent myocardial infarction, and heart failure) in patients with AMI. PMID:26089856

Liquefaction and soil failure during 1994 northridge earthquake

USGS Publications Warehouse

Holzer, T.L.

1999-01-01

The 1994 Northridge, Calif., earthquake caused widespread permanent ground deformation on the gently sloping alluvial fan surface of the San Fernando Valley. The ground cracks and distributed deformation damaged both pipelines and surface structures. To evaluate the mechanism of soil failure, detailed subsurface investigations were conducted at four sites. Three sites are underlain by saturated sandy silts with low standard penetration test and cone penetration test values. These soils are similar to those that liquefied during the 1971 San Fernando earthquake, and are shown by widely used empirical relationships to be susceptible to liquefaction. The remaining site is underlain by saturated clay whose undrained shear strength is approximately half the value of the earthquake-induced shear stress at this location. This study demonstrates that the heterogeneous nature of alluvial fan sediments in combination with variations in the ground-water table can be responsible for complex patterns of permanent ground deformation. It may also help to explain some of the spatial variability of strong ground motion observed during the 1994 earthquake. ?? ASCE,.

AN EXAMINATION OF DATA ON IOWA SCHOOL CHILDREN TO DETERMINE PATTERNS OF PERFORMANCE AND "DOWNSTREAM EFFECTS" OF EARLY DEPRESSED SCORES.

ERIC Educational Resources Information Center

FITZSIMMONS, STEPHEN J.

VARIOUS PERFORMANCE PATTERNS WERE STUDIED TO DETERMINE IF EARLY LIMITED FAILURE LEADS TO GENERALIZED FAILURE IN A NUMBER OF AREAS. THE SUBJECTS, 258 DISADVANTAGED URBAN CHILDREN FROM FOUR SCHOOL DISTRICTS IN IOWA, HAD ONE OR MORE SCORES ON THE IOWA TEST OF BASIC SKILLS (ITBS) AT OR BELOW THE 33D PERCENTILE ON NATIONAL NORMS. THEIR PERFORMANCES ON…

Development of acute pancreatitis caused by sodium valproate in a patient with bipolar disorder on hemodialysis for chronic renal failure: a case report.

PubMed

Okayasu, Hiroaki; Shinozaki, Takahiro; Osone, Akira; Ozeki, Yuji; Shimoda, Kazutaka

2014-03-29

Cases of acute pancreatitis caused by sodium valproate (VPA) have been reported by many authors thus far. However, most of these were cases with epilepsy. Chronic renal failure is also regarded as a risk factor for acute pancreatitis. Here, we report a case of acute pancreatitis development due to VPA in a patient with bipolar disorder on hemodialysis for chronic renal failure. The patient was a 52-year-old Japanese male who was diagnosed as bipolar disorder on hemodialysis for renal failure. He was treated with VPA and manic symptoms gradually stabilized. However, the patient complained of severe abdominal pain. Blood amylase was found to be markedly high, and computed tomography revealed pancreatomegaly and an increased amount of peripancreatic fat. Hence, we diagnosed the case as acute pancreatitis caused by VPA. We discontinued oral medication, and he was started on a pancreatic enzyme inhibitor, antibiotics, and transfusion, and he showed improvement. It has been reported that acute pancreatitis induced by VPA is caused by intermediate metabolites of VPA. We consider that patients with renal failure are prone to pancreatitis caused by VPA because of the accumulation of these intermediate metabolites. We need close monitoring for serious adverse effects such as pancreatitis when we prescribe VPA to patients with bipolar disorder on hemodialysis for chronic renal failure, although VPA is safer than other mood stabilizers.

Study on Interference Suppression Algorithms for Electronic Noses: A Review

PubMed Central

Liang, Zhifang; Zhang, Ci; Sun, Hao; Liu, Tao

2018-01-01

Electronic noses (e-nose) are composed of an appropriate pattern recognition system and a gas sensor array with a certain degree of specificity and broad spectrum characteristics. The gas sensors have their own shortcomings of being highly sensitive to interferences which has an impact on the detection of target gases. When there are interferences, the performance of the e-nose will deteriorate. Therefore, it is urgent to study interference suppression techniques for e-noses. This paper summarizes the sources of interferences and reviews the advances made in recent years in interference suppression for e-noses. According to the factors which cause interference, interferences can be classified into two types: interference caused by changes of operating conditions and interference caused by hardware failures. The existing suppression methods were summarized and analyzed from these two aspects. Since the interferences of e-noses are uncertain and unstable, it can be found that some nonlinear methods have good effects for interference suppression, such as methods based on transfer learning, adaptive methods, etc. PMID:29649152

Physically demanding jobs and occupational injury and disability in the U.S. Army.

PubMed

Hollander, Ilyssa E; Bell, Nicole S

2010-10-01

Effective job assignments should take into account physical capabilities to perform required tasks. Failure to do so is likely to result in increased injuries and musculoskeletal disability. To evaluate the association between job demands and health outcomes among U.S. Army soldiers. Multivariate Cox proportional hazards analysis is used to describe associations between job demands, hospitalizations, and disability among 261,096 enlisted Army soldiers in heavily, moderately, and lightly physically demanding occupations (2000-2005) who were followed for up to 5 years. Controlling for gender, race, and age, soldiers in heavily demanding jobs were at increased risk for any-cause injury, on-duty injuries, any-cause hospitalizations, and any-cause disability, but not for musculoskeletal disability. Army job assignments should more accurately match physical capabilities to job demands and/or jobs should be redesigned to reduce injuries. Though musculoskeletal disorders are often the result of acute injury, the demographic and occupational risk patterns differ from acute injury.

Social Norms: Do We Love Norms Too Much?

PubMed

Bell, David C; Cox, Mary L

2015-03-01

Social norms are often cited as the cause of many social phenomena, especially as an explanation for prosocial family and relationship behaviors. And yet maybe we love the idea of social norms too much, as suggested by our failure to subject them to rigorous test. Compared to the detail in social norms theoretical orientations, there is very little detail in tests of normative theories. To provide guidance to researchers who invoke social norms as explanations, we catalog normative orientations that have been proposed to account for consistent patterns of action. We call on researchers to conduct tests of normative theories and the processes such theories assert.

Electron wind in strong wave guide fields

NASA Astrophysics Data System (ADS)

Krienen, F.

1985-03-01

The X-ray activity observed near highly powered waveguide structures is usually caused by local electric discharges originating from discontinuities such as couplers, tuners or bends. In traveling waves electrons move in the direction of the power flow. Seed electrons can multipactor in a traveling wave, the moving charge pattern is different from the multipactor in a resonant structure and is self-extinguishing. The charge density in the wave guide will modify impedance and propagation constant of the wave guide. The radiation level inside the output wave guide of the SLAC, 50 MW, S-band, klystron is estimated. Possible contributions of radiation to window failure are discussed.

Social Norms: Do We Love Norms Too Much?

PubMed Central

Bell, David C.; Cox, Mary L.

2014-01-01

Social norms are often cited as the cause of many social phenomena, especially as an explanation for prosocial family and relationship behaviors. And yet maybe we love the idea of social norms too much, as suggested by our failure to subject them to rigorous test. Compared to the detail in social norms theoretical orientations, there is very little detail in tests of normative theories. To provide guidance to researchers who invoke social norms as explanations, we catalog normative orientations that have been proposed to account for consistent patterns of action. We call on researchers to conduct tests of normative theories and the processes such theories assert. PMID:25937833

Robust Feature Matching in Terrestrial Image Sequences

NASA Astrophysics Data System (ADS)

Abbas, A.; Ghuffar, S.

2018-04-01

From the last decade, the feature detection, description and matching techniques are most commonly exploited in various photogrammetric and computer vision applications, which includes: 3D reconstruction of scenes, image stitching for panoramic creation, image classification, or object recognition etc. However, in terrestrial imagery of urban scenes contains various issues, which include duplicate and identical structures (i.e. repeated windows and doors) that cause the problem in feature matching phase and ultimately lead to failure of results specially in case of camera pose and scene structure estimation. In this paper, we will address the issue related to ambiguous feature matching in urban environment due to repeating patterns.

Evaluation of the Linde Flow Warning Device,

DTIC Science & Technology

1965-12-30

the cause of the failure. It was not possible to disassemble the pressure switch or to determine the cause of failure. The warning device was...simple means of causing an actuat ion of a pressure switch . The sensing device used in the apparatus proved to be too del icate for the operat ion to

[Obesity and the prognosis of heart failure: the obesity paradox, myth or reality?].

PubMed

Bounhoure, Jean-Paul; Galinier, Michel; Roncalli, Jerôme; Massabuau, Pierre

2014-01-01

Obesity has now reached epidemic proportions worldwide. Obesity is associated with numerous comorbidities, including hypertension, lipid disorders and type II diabetes, and is also a major cause of cardiovascular disease, coronary disease, heart failure, atrial fibrillation, and sudden death. Obesity is the main cause of heart failure in respectively 11% and 14% of cases in men and women. The Framingham study showed that, after correction for other risk factors, each point increase in the body mass index raises the risk of heart failure by 5% in men and 7% in women. Obesity increases the heart workload, causes left ventricular hypertrophy, and impairs both diastolic and systolic function. The most common form of heart failure is diastolic dysfunction, and heart failure in obese individuals is associated with preserved systolic function. Despite these comorbidities and the severity of heart failure, numerous studies have revealed an "obesity paradox" in which overweight and obese individuals with heart failure appear to have a better prognosis than non overweight subjects. This review summarizes the adverse cardiac effects of this nutritional disease, the results of some studies supporting the obesity paradox, the better survival rate of obese patients with heart failure. Potential explanations for these surprising data include the possibility that a number of obese patients may simply not have heart failure, as well as methodological bias, and protective effects of adipose tissue. Further studies of large populations are needed to determine how obesity may improve the prognosis of heart failure.

Patients with the worst outcomes after paracetamol (acetaminophen)-induced liver failure have an early monocytopenia.

PubMed

Moore, J K; MacKinnon, A C; Man, T Y; Manning, J R; Forbes, S J; Simpson, K J

2017-02-01

Acute liver failure (ALF) is associated with significant morbidity and mortality. Studies have implicated the immune response, especially monocyte/macrophages as being important in dictating outcome. To investigate changes in the circulating monocytes and other immune cells serially in patients with ALF, relate these with cytokine concentrations, monocyte gene expression and patient outcome. In a prospective case-control study in the Scottish Liver Transplant Unit, Royal Infirmary Edinburgh, 35 consecutive patients admitted with paracetamol-induced liver failure (POD-ALF), 10 patients with non-paracetamol causes of ALF and 16 controls were recruited. The peripheral blood monocyte phenotype was analysed by flow cytometry, circulating cytokines quantified by protein array and monocyte gene expression array performed and related to outcome. On admission, patients with worst outcomes after POD-ALF had a significant monocytopenia, characterised by reduced classical and expanded intermediate monocyte population. This was associated with reduced circulating lymphocytes and natural killer cells, peripheral cytokine patterns suggestive of a 'cytokine storm' and increased concentrations of cytokines associated with monocyte egress from the bone marrow. Gene expression array did not differentiate patient outcome. At day 4, there was no significant difference in monocyte, lymphocyte or natural killer cells between survivors and the patients with adverse outcomes. Severe paracetamol liver failure is associated with profound changes in the peripheral blood compartment, particularly in monocytes, related with worse outcomes. This is not seen in patients with non-paracetamol-induced liver failure. Significant monocytopenia on admission may allow earlier clarification of prognosis, and it highlights a potential target for therapeutic intervention. © 2016 John Wiley & Sons Ltd.

Clinical patterns and major causes of infertility among Sudanese couples.

PubMed

Elussein, Elsir A; Magid, Yagoub M; Omer, Maha M; Adam, Ishag

2008-10-01

An understanding of the medical causes of infertility is crucial in order to reduce incidences of Infertility and for improving the clinical management of infertility. Although there were much data on infertility in other African countries, no data exist on infertility in Sudan. Seven hundred and ten Sudanese couples were investigated for the infertility in Khartoum Fertility Center, Sudan: 443 (62.4%) had primary infertility and 267 (37.6%) had secondary infertility. The mean (standard deviation) duration of the infertility was 5.2 (4.3) years. A positive male factor alone was found in 257 (36.2%) couples and a female factor in 350 (49.3%) couples: eleven (1.5%) couples had a combination of male and female factors: and the cause of infertility was unexplained in 92 (13.0%) couples. Oligozoospermia and asthenozoospermia were factors responsible for 16.8% and 17.5% of male infertility, respectively. Failure of ovulation (60.3%) was the most common cause of female infertility. The study revealed a high proportion of secondary infertility and a greater contribution of the female factors to infertility.

Pattern of infection, therapy, outcome and risk stratification of patients with febrile neutropenia in a tertiary care oncology hospital in India.

PubMed

Noronha, V; Joshi, A; Patil, V M; Bhosale, B; Muddu, V K; Banavali, S; Kelkar, R; Prabhash, K

2014-01-01

Indian febrile neutropenia (FN) data are limited, especially in adult solid tumor patients. The aim was to study patterns of presentation, source of infection, management and outcome and to evaluate the factors which may correlate with outcome. A retrospective analysis of prospective data of FN patients at a tertiary care oncology teaching hospital in India between 2007 and 2012. A standardized form was filled for each patient. Patient management was at the discretion of the treating physician. Multinational Association for Supportive Care in Cancer (MASCC) score was retrospectively calculated. Failure of therapy was defined as death, organ failure, shifting from outpatient to inpatient or requirement of intensive care support. SPSS version 16 was used for analysis. A total of 388 FN episodes were included: 256 in hematolymphoid and 132 in solid tumor patients. 156 episodes were high-risk by MASCC score. Focus of infection was clinical in 45% and radiologic in 16%. Blood cultures were positive in 18% cases, most commonly Gram-negative organisms (72%). 93% patients were treated with an antibiotic combination of third-generation cephalosporin/beta-lactamase inhibitor, with aminoglycoside or fluoroquinolone. Antibiotic sensitivity to ceftriaxone was low at 38% while sensitivity to cefoperazone/sulbactam and piperacillin/tazobactam ranged between 50% and 55% and for carbapenems 75%. Failure of therapy occurred in 156 episodes, most commonly due to the need for second line antibiotics. Mortality was 5.5%. On univariate analysis, MASCC score, age, type of malignancy, prophylactic growth factors, presence of focus of infection, hemoglobin and nadir platelet count correlated with FN complications. Gram-negative bacteremia continues to be the predominant cause of FN in our setup.

Pattern and presentation of cardiac diseases among patients with chronic kidney disease attending a national referral hospital in Uganda: a cross sectional study.

PubMed

Babua, Christopher; Kalyesubula, Robert; Okello, Emmy; Kakande, Barbara; Sebatta, Erias; Mungoma, Michael; Mondo, Charles

2015-08-04

Chronic kidney disease is a risk factor for development of cardiovascular diseases. Cardiovascular diseases are the primary cause of morbidity and mortality in patients with chronic kidney disease. There is limited data on cardiovascular diseases among chronic kidney disease patients in resource limited settings including Uganda. We determined the prevalence and patterns of cardiac diseases among patients with chronic kidney disease attending the nephrology outpatient clinic in Mulago National Referral Hospital in Uganda. This was a cross sectional study in which two hundred seventeen patients with chronic kidney disease were recruited over a period of 9 months. Data on demographic characteristics and risk factors for cardiovascular diseases were collected using a standardized questionnaire. Cardiac evaluation was done using resting electrocardiography and transthoracic echocardiography performed for all study participants and findings entered into a data sheet. One hundred eleven (51.2 %) of the 217 participants were male. Mean age was 42.8 years. One hundred eighteen (54.4 %) of patients had either eccentric or concentric left ventricular hypertrophy. Patients with left ventricular hypertrophy were more likely to be hypertensive (p < 0.001) or anemic (p = 0.034). Up to 9.2 % of study subjects had valvular heart disease (rheumatic or degenerative) and 22 % had pericarditis. Forty one patients (18.9 %) had left ventricular systolic failure (Ejection fraction < 50 %). There was a higher prevalence of systolic failure in patients with left ventricular hypertrophy (21 % vs. 16 %) although this was not statistically significant, p = 0.346. Thirty eight participants (17.5 %) had diastolic failure while 2 % had cardiac rhythm abnormalities. Cardiac abnormalities are common in a predominantly young African population with CKD. Clinicians should routinely screen and manage cardiovascular disease in CKD patients.

Pheochromocytoma presenting with rhabdomyolysis and acute renal failure: a case report.

PubMed

Celik, Huseyin; Celik, Ozlem; Guldiken, Sibel; Inal, Volkan; Puyan, Fulya Oz; Tugrul, Armagan

2014-02-01

Rhabdomyolysis ranges from an asymptomatic illness with elevated creatine kinase levels to a life-threatening condition associated with extreme elevations in creatine kinase, electrolyte imbalances, acute renal failure, and disseminated intravascular coagulation. The most common causes are crush injury, overexertion, alcohol abuse, certain medicines, and toxic substances. A number of electrolyte abnormalities and endocrinopathies, including hypothyroidism, thyrotoxicosis, diabetic ketoacidosis, nonketotic hyperosmolar state, and hyperaldosteronism, cause rhabdomyolysis. Rhabdomyolysis and acute renal failure are unusual manifestations of pheochromocytoma. There are a few case reports with pheochromocytoma presenting rhabdomyolysis and acute renal failure. Herein, we report a case with pheochromocytoma crisis presenting with rhabdomyolysis and acute renal failure.

Orthopaedic jack for scoliosis surgery purposes: Concept and design

NASA Astrophysics Data System (ADS)

Supriadi, Sugeng; Radhana, Rakha M.; Hidayanto, Taufik Eko; Whulanza, Yudan; Ali, Notario, Nanda; Rahyussalim

2017-02-01

Scoliosis surgery is one of the most difficult orthopedic surgery that have been committed today as the failure rate of orthopedic surgery for adult patients is 15%. Aside from the long duration of surgery, this surgical failure is caused by failure in biomedical instrumentation. Furthermore, this kind of failure is causing inefficiency of the surgery. With current known orthopedic surgery method, three surgeons are needed in a single orthopedic surgery. In fact, a single surgery can take up to 8 hours to be done, which increases the risk of surgical failure. Based on this problem, authors hope that our orthopedic jacks could solve the problem.

Accelerating yield ramp through design and manufacturing collaboration

NASA Astrophysics Data System (ADS)

Sarma, Robin C.; Dai, Huixiong; Smayling, Michael C.; Duane, Michael P.

2004-12-01

Ramping an integrated circuit from first silicon bring-up to production yield levels is a challenge for all semiconductor products on the path to profitable market entry. Two approaches to accelerating yield ramp are presented. The first is the use of laser mask writers for fast throughput, high yield, and cost effective pattern transfer. The second is the use of electrical test to find a defect and identify the physical region to probe in failure analysis that is most likely to uncover the root cause. This provides feedback to the design team on modifications to make to the design to avoid the yield issue in a future tape-out revision. Additionally, the process parameter responsible for the root cause of the defect is forward annotated through the design, mask and wafer coordinate systems so it can be monitored in-line on subsequent lots of the manufacturing run. This results in an improved recipe for the manufacturing equipment to potentially prevent the recurrence of the defect and raise yield levels on the following material. The test diagnostics approach is enabled by the seamless traceability of a feature across the design, photomask and wafer, made possible by a common data model for design, mask pattern generation and wafer fabrication.

Star fruit (Averrhoa carambola) intoxication: an important cause of consciousness disturbance in patients with renal failure.

PubMed

Chang, Chin-Tung; Chen, Yung-Chang; Fang, Ji-Tseng; Huang, Chiu-Ching

2002-05-01

Star fruit intoxication is a rare cause of consciousness disturbance in patients with renal failure. Most cases in the literature are uremic patients on maintenance dialysis. We present a patient with chronic renal failure, who was not on dialysis program yet, suffered from star fruit intoxication with presentation of consciousness disturbance and successfully managed by a session of hemodialysis.

[Pain, flare-ups and failures in root canal therapy].

PubMed

Moorer, W R

1989-10-01

In this overview the incidences and causes of pain, flare-ups and failures that occur after root canal therapy are discussed. Infection is considered the most important single, underlying determinant of the many factors that may cause pain and failures. Therefore, strict adherence to recognized therapeutic principles of shaping, disinfection and filling, in addition to proper aftercare, is of importance to diminish postoperative sequelae.

Tin Whiskers: A History of Documented Electrical System Failures

NASA Technical Reports Server (NTRS)

Leidecker, Henning; Brusse, Jay

2006-01-01

This viewgraph presentation reviews the history of tin and other metal whiskers, and the damage they have caused equipment. There are pictures of whiskers on various pieces of electronic equipment, and microscopic views of whiskers. There is also a chart with information on the documented failures associated with metal whiskers. There are also examples of on-orbit failures believed to be caused by whiskers.

Improvement program for polycarbonate capacitors. [hermetically sealed, and ac wound

NASA Technical Reports Server (NTRS)

Bailey, R. R.; Waterman, K. D.

1973-01-01

Hermetically sealed, wound, AC, polycarbonate capacitors incorporating design improvements recommended in a previous study were designed and built. A 5000 hour, 400 Hz ac life test was conducted using 384 of these capacitors to verify the adequacy of the design improvements. The improvements incorporated in the capacitors designed for this program eliminated the major cause of failure found in the preceding work, termination failure. A failure cause not present in the previous test became significant in this test with capacitors built from one lot of polycarbonate film. The samples from this lot accounted for 25 percent of the total test complement. Analyses of failed samples showed that the film had an excessive solvent content. This solvent problem was found in 37 of the total 46 failures which occurred in this test. The other nine were random failures resulting from causes such as seal leaks, foreign particles, and possibly wrinkles.

Vibrational fatigue failures in short cantilevered piping with socket-welding fittings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, J.K.

1996-12-01

Approximately 80% of the vibrational fatigue failures in nuclear power plants have been caused by high cycle vibrational fatigue. Many of these failures have occurred in short, small bore (2 in. nominal diameter and smaller), unbraced, cantilevered piping with socket-welding fittings. The fatigue failures initiated in the socket welds. These failures have been unexpected, and have caused costly, unscheduled outages in some cases. In order to reduce the number of vibrational fatigue failures in these short cantilevered pipes, an acceleration based vibrational fatigue screening criteria was developed under Electric Power Research Institute (EPRI) sponsorship. In this paper, the acceleration basedmore » criteria will be compared to the results obtained from detailed dynamic modeling of a short, cantilevered pipe.« less

STS-3 main parachute failure

NASA Technical Reports Server (NTRS)

Runkle, R.; Henson, K.

1982-01-01

A failure analysis of the parachute on the Space Transportation System 3 flight's solid rocket booster's is presented. During the reentry phase of the two Solid Rocket Boosters (SRBs), one 115 ft diameter main parachute failed on the right hand SRB (A12). This parachute failure caused the SRB to impact the Ocean at 110 ft/sec in lieu of the expected 3 parachute impact velocity of 88 ft/sec. This higher impact velocity relates directly to more SRB aft skirt and more motor case damage. The cause of the parachute failure, the potential risks of losing an SRB as a result of this failure, and recommendations to ensure that the probability of chute failures of this type in the future will be low are discussed.

Cracking-assisted fabrication of nanoscale patterns for micro/nanotechnological applications

NASA Astrophysics Data System (ADS)

Kim, Minseok; Kim, Dong-Joo; Ha, Dogyeong; Kim, Taesung

2016-05-01

Cracks are frequently observed in daily life, but they are rarely welcome and are considered as a material failure mode. Interestingly, cracks cause critical problems in various micro/nanofabrication processes such as colloidal assembly, thin film deposition, and even standard photolithography because they are hard to avoid or control. However, increasing attention has been given recently to control and use cracks as a facile, low-cost strategy for producing highly ordered nanopatterns. Specifically, cracking is the breakage of molecular bonds and occurs simultaneously over a large area, enabling fabrication of nanoscale patterns at both high resolution and high throughput, which are difficult to obtain simultaneously using conventional nanofabrication techniques. In this review, we discuss various cracking-assisted nanofabrication techniques, referred to as crack lithography, and summarize the fabrication principles, procedures, and characteristics of the crack patterns such as their position, direction, and dimensions. First, we categorize crack lithography techniques into three technical development levels according to the directional freedom of the crack patterns: randomly oriented, unidirectional, or multidirectional. Then, we describe a wide range of novel practical devices fabricated by crack lithography, including bioassay platforms, nanofluidic devices, nanowire sensors, and even biomimetic mechanosensors.

Accelerated life-test methods and results for implantable electronic devices with adhesive encapsulation.

PubMed

Huang, Xuechen; Denprasert, Petcharat May; Zhou, Li; Vest, Adriana Nicholson; Kohan, Sam; Loeb, Gerald E

2017-09-01

We have developed and applied new methods to estimate the functional life of miniature, implantable, wireless electronic devices that rely on non-hermetic, adhesive encapsulants such as epoxy. A comb pattern board with a high density of interdigitated electrodes (IDE) could be used to detect incipient failure from water vapor condensation. Inductive coupling of an RF magnetic field was used to provide DC bias and to detect deterioration of an encapsulated comb pattern. Diodes in the implant converted part of the received energy into DC bias on the comb pattern. The capacitance of the comb pattern forms a resonant circuit with the inductor by which the implant receives power. Any moisture affects both the resonant frequency and the Q-factor of the resonance of the circuitry, which was detected wirelessly by its effects on the coupling between two orthogonal RF coils placed around the device. Various defects were introduced into the comb pattern devices to demonstrate sensitivity to failures and to correlate these signals with visual inspection of failures. Optimized encapsulation procedures were validated in accelerated life tests of both comb patterns and a functional neuromuscular stimulator under development. Strong adhesive bonding between epoxy and electronic circuitry proved to be necessary and sufficient to predict 1 year packaging reliability of 99.97% for the neuromuscular stimulator.

Fault tree analysis of most common rolling bearing tribological failures

NASA Astrophysics Data System (ADS)

Vencl, Aleksandar; Gašić, Vlada; Stojanović, Blaža

2017-02-01

Wear as a tribological process has a major influence on the reliability and life of rolling bearings. Field examinations of bearing failures due to wear indicate possible causes and point to the necessary measurements for wear reduction or elimination. Wear itself is a very complex process initiated by the action of different mechanisms, and can be manifested by different wear types which are often related. However, the dominant type of wear can be approximately determined. The paper presents the classification of most common bearing damages according to the dominant wear type, i.e. abrasive wear, adhesive wear, surface fatigue wear, erosive wear, fretting wear and corrosive wear. The wear types are correlated with the terms used in ISO 15243 standard. Each wear type is illustrated with an appropriate photograph, and for each wear type, appropriate description of causes and manifestations is presented. Possible causes of rolling bearing failure are used for the fault tree analysis (FTA). It was performed to determine the root causes for bearing failures. The constructed fault tree diagram for rolling bearing failure can be useful tool for maintenance engineers.

[What is the cause of failure of local anesthesia?].

PubMed

Vinckier, F

2000-01-01

Local anesthesia fails in 10% of cases of inferior alveolar nerve block and 7% of all cases of local anesthesia in general practice. Possible causes of failure are infection, wrong selection of local anesthetic solution, technical mistakes, anatomical variations with accessory innervation and anxiety of the patient. In this publication we discuss reasons for frequent failure in case of infection and in inferior alveolar nerve block. Understanding the mechanism of failure in local anesthesia, makes it possible to formulate guidelines to guarantee success. These measures are discussed in detail.

76 FR 63355 - Proposed Information Collection (Prevalence and Clinical course of Depression Among patients with...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-12

... (Prevalence and Clinical course of Depression Among patients with Heart Failure); Comment Request AGENCY... information needed to identify the patterns of depression in heart failure patients. DATES: Written comments...: Prevalence and Clinical Course of Depression Among Patients with Heart Failure, VA HSR&D, Nursing Research...

8 CFR 208.10 - Failure to appear at an interview before an asylum officer or failure to follow requirements for...

Code of Federal Regulations, 2011 CFR

2011-01-01

... asylum officer or failure to follow requirements for fingerprint processing. 208.10 Section 208.10 Aliens... asylum officer or failure to follow requirements for fingerprint processing. Failure to appear for a... right to an interview. Failure to comply with fingerprint processing requirements without good cause may...

8 CFR 208.10 - Failure to appear at an interview before an asylum officer or failure to follow requirements for...

Code of Federal Regulations, 2010 CFR

2010-01-01

... asylum officer or failure to follow requirements for fingerprint processing. 208.10 Section 208.10 Aliens... asylum officer or failure to follow requirements for fingerprint processing. Failure to appear for a... right to an interview. Failure to comply with fingerprint processing requirements without good cause may...

8 CFR 208.10 - Failure to appear at an interview before an asylum officer or failure to follow requirements for...

Code of Federal Regulations, 2013 CFR

2013-01-01

... asylum officer or failure to follow requirements for fingerprint processing. 208.10 Section 208.10 Aliens... asylum officer or failure to follow requirements for fingerprint processing. Failure to appear for a... right to an interview. Failure to comply with fingerprint processing requirements without good cause may...

8 CFR 208.10 - Failure to appear at an interview before an asylum officer or failure to follow requirements for...

Code of Federal Regulations, 2014 CFR

2014-01-01

... asylum officer or failure to follow requirements for fingerprint processing. 208.10 Section 208.10 Aliens... asylum officer or failure to follow requirements for fingerprint processing. Failure to appear for a... right to an interview. Failure to comply with fingerprint processing requirements without good cause may...

8 CFR 208.10 - Failure to appear at an interview before an asylum officer or failure to follow requirements for...

Code of Federal Regulations, 2012 CFR

2012-01-01

... asylum officer or failure to follow requirements for fingerprint processing. 208.10 Section 208.10 Aliens... asylum officer or failure to follow requirements for fingerprint processing. Failure to appear for a... right to an interview. Failure to comply with fingerprint processing requirements without good cause may...

Heart Failure Questions to Ask Your Doctor

MedlinePlus

... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Heart Failure Questions to Ask Your Doctor Updated:May 9, ... you? This content was last reviewed May 2017. Heart Failure • Home • About Heart Failure • Causes and Risks for ...

Failure analysis of a tool steel torque shaft

NASA Technical Reports Server (NTRS)

Reagan, J. R.

1981-01-01

A low design load drive shaft used to deliver power from an experimental exhaust heat recovery system to the crankshaft of an experimental diesel truck engine failed during highway testing. An independent testing laboratory analyzed the failure by routine metallography and attributed the failure to fatigue induced by a banded microstructure. Visual examination by NASA of the failed shaft plus the knowledge of the torsional load that it carried pointed to a 100 percent ductile failure with no evidence of fatigue. Scanning electron microscopy confirmed this. Torsional test specimens were produced from pieces of the failed shaft and torsional overload testing produced identical failures to that which had occurred in the truck engine. This pointed to a failure caused by a high overload and although the microstructure was defective it was not the cause of the failure.

Diatom ooze as weak layer for submarine mega-slides off Northwest Africa: Evidence from core-seismic integration in the Cap Blanc Slide area

NASA Astrophysics Data System (ADS)

Urlaub, Morelia; Geersen, Jacob; Krastel, Sebastian; Schwenk, Tilmann

2017-04-01

The continental slope off Northwest Africa has experienced at least four mega-landslides, each affecting over 20,000 km2 of seafloor. Although the landslides lie more than 400 km apart, they have many similar characteristics, including stepped headwall patterns and several bedding-parallel glide planes at slope angles of <2°. This morphology suggests that failures took place along multiple mechanically weak sedimentary layers that are present at different stratigraphic depths. From all Northwest African mega-landslides the Cap Blanc Slide, situated off the coasts of Mauretania and West Sahara, offers an unprecedented possibility to advance our understanding of landslide causes. ODP site 658 (Leg 108) was drilled within the evacuation area of the slide, recovering its glide plane. In addition, site 658 also recovered the glide plane and the overlying undisturbed sedimentary sequence of a younger slope failure, which took place within the evacuation are of the main Cap Blanc Slide at some distance to the borehole. We use core-seismic integration to characterize the glide planes as well as to determine the timing of slope failures. The sediments just above both glide planes have particularly high biogenic opal contents owing to the presence of large amounts of diatom microfossils. Diatoms are hollow structures of microfossil skeletons, which contain large amounts of bound and intraskeletal water. When a critical stress level is exceeded during compaction, the microfossil shells break. The stored water is released causing a sudden increase in pore pressure, which may facilitate slope failure. We therefore suggest that diatom oozes acted as weak layers in the case of the Cap Blanc Slide. Pronounced biogenic opal maxima occur during glacial terminations and are expected all along the Northwest African continental margin. We thus hypothesize that mega-slides off Northwest Africa, and potentially also at other continental margins, are preconditioned by episodically high deposition of biogenic opal.

Gas Flow Tightly Coupled to Elastoplastic Geomechanics for Tight- and Shale-Gas Reservoirs: Material Failure and Enhanced Permeability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jihoon; Moridis, George J.

We investigate coupled flow and geomechanics in gas production from extremely low permeability reservoirs such as tight and shale gas reservoirs, using dynamic porosity and permeability during numerical simulation. In particular, we take the intrinsic permeability as a step function of the status of material failure, and the permeability is updated every time step. We consider gas reservoirs with the vertical and horizontal primary fractures, employing the single and dynamic double porosity (dual continuum) models. We modify the multiple porosity constitutive relations for modeling the double porous continua for flow and geomechanics. The numerical results indicate that production of gasmore » causes redistribution of the effective stress fields, increasing the effective shear stress and resulting in plasticity. Shear failure occurs not only near the fracture tips but also away from the primary fractures, which indicates generation of secondary fractures. These secondary fractures increase the permeability significantly, and change the flow pattern, which in turn causes a change in distribution of geomechanical variables. From various numerical tests, we find that shear failure is enhanced by a large pressure drop at the production well, high Biot's coefficient, low frictional and dilation angles. Smaller spacing between the horizontal wells also contributes to faster secondary fracturing. When the dynamic double porosity model is used, we observe a faster evolution of the enhanced permeability areas than that obtained from the single porosity model, mainly due to a higher permeability of the fractures in the double porosity model. These complicated physics for stress sensitive reservoirs cannot properly be captured by the uncoupled or flow-only simulation, and thus tightly coupled flow and geomechanical models are highly recommended to accurately describe the reservoir behavior during gas production in tight and shale gas reservoirs and to smartly design production scenarios.« less

Gas Flow Tightly Coupled to Elastoplastic Geomechanics for Tight- and Shale-Gas Reservoirs: Material Failure and Enhanced Permeability

DOE PAGES

Kim, Jihoon; Moridis, George J.

2014-12-01

We investigate coupled flow and geomechanics in gas production from extremely low permeability reservoirs such as tight and shale gas reservoirs, using dynamic porosity and permeability during numerical simulation. In particular, we take the intrinsic permeability as a step function of the status of material failure, and the permeability is updated every time step. We consider gas reservoirs with the vertical and horizontal primary fractures, employing the single and dynamic double porosity (dual continuum) models. We modify the multiple porosity constitutive relations for modeling the double porous continua for flow and geomechanics. The numerical results indicate that production of gasmore » causes redistribution of the effective stress fields, increasing the effective shear stress and resulting in plasticity. Shear failure occurs not only near the fracture tips but also away from the primary fractures, which indicates generation of secondary fractures. These secondary fractures increase the permeability significantly, and change the flow pattern, which in turn causes a change in distribution of geomechanical variables. From various numerical tests, we find that shear failure is enhanced by a large pressure drop at the production well, high Biot's coefficient, low frictional and dilation angles. Smaller spacing between the horizontal wells also contributes to faster secondary fracturing. When the dynamic double porosity model is used, we observe a faster evolution of the enhanced permeability areas than that obtained from the single porosity model, mainly due to a higher permeability of the fractures in the double porosity model. These complicated physics for stress sensitive reservoirs cannot properly be captured by the uncoupled or flow-only simulation, and thus tightly coupled flow and geomechanical models are highly recommended to accurately describe the reservoir behavior during gas production in tight and shale gas reservoirs and to smartly design production scenarios.« less

49 CFR 173.32 - Requirements for the use of portable tanks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... within a nozzle or within a coupling. The installation must be made in such a manner as to reasonably assure that any undue strain which causes failure requiring functioning of the valve shall cause failure...

49 CFR 173.32 - Requirements for the use of portable tanks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... within a nozzle or within a coupling. The installation must be made in such a manner as to reasonably assure that any undue strain which causes failure requiring functioning of the valve shall cause failure...

49 CFR 173.32 - Requirements for the use of portable tanks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... within a nozzle or within a coupling. The installation must be made in such a manner as to reasonably assure that any undue strain which causes failure requiring functioning of the valve shall cause failure...

49 CFR 173.32 - Requirements for the use of portable tanks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... within a nozzle or within a coupling. The installation must be made in such a manner as to reasonably assure that any undue strain which causes failure requiring functioning of the valve shall cause failure...

Mechanisms, predictors, and trends of electrical failure of Riata leads.

PubMed

Cheung, Jim W; Al-Kazaz, Mohamed; Thomas, George; Liu, Christopher F; Ip, James E; Bender, Seth R; Siddiqi, Faisal K; Markowitz, Steven M; Lerman, Bruce B

2013-10-01

Riata and Riata ST implantable cardioverter-defibrillator leads have been shown to be prone to structural and electrical failure. To determine predictors, mechanisms, and temporal patterns of Riata/ST lead electrical failure. All 314 patients who underwent Riata/ST lead implantation at our institution with greater than or equal to 90 days of follow-up were studied. The Kaplan-Meier analysis of lead survival was performed. Results from the returned product analysis of explanted leads with electrical lead failure were recorded. During a median follow-up of 4.1 years, the Riata lead electrical failure rate was 6.6%. The rate of externalized conductors among failed leads was 57%. The engineering analysis of 10 explanted leads revealed 5 (50%) leads with electrical failure owing to breach of ethylene tetrafluoroethylene conductor coating. Female gender (hazard ratio 2.7; 95% confidence interval 1.1-6.7; P = .04) and age (hazard ratio 0.95; 95% confidence interval 0.92-0.97; P < .001) were multivariate predictors of lead failure. By using log-log analysis, we noted that the rate of Riata lead failure initially increased exponentially with a power of 2.1 but leads surviving past 4 years had a linear pattern of lead failure with a power of 1.0. Younger age and female gender are independent predictors of Riata lead failure. Loss of integrity of conductor cables with ethylene tetrafluoroethylene coating is an important mode of electrical failure of the Riata lead. Further study of Riata lead failure trends is warranted to guide lead management. © 2013 Heart Rhythm Society. All rights reserved.

Green technologies for reducing slope erosion.

DOT National Transportation Integrated Search

2010-01-01

As climate change alters precipitation patterns, departments of transportation will increasingly face the problem of : slope failures, which already cost California millions of dollars in repair work annually. Caltrans hopes to prevent : these failur...

The Role of Academic Failure in Hyperactive Behavior

ERIC Educational Resources Information Center

Cunningham, Charles E.; Barkley, Russell A.

1978-01-01

A model and supporting research are presented which suggest that academic failure resulting from a variety of etiological factors is sufficient to generate the behavioral patterns observed in many hyperactive children. (CL)

Failure Rates and Patterns of Recurrence in Patients With Resected N1 Non-Small-Cell Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varlotto, John M., E-mail: jvarlotto@hmc.psu.edu; Medford-Davis, Laura Nyshel; Recht, Abram

2011-10-01

Purpose: To examine the local and distant recurrence rates and patterns of failure in patients undergoing potentially curative resection of N1 non-small-cell lung cancer. Methods and Materials: The study included 60 consecutive unirradiated patients treated from 2000 to 2006. Median follow-up was 30 months. Failure rates were calculated by the Kaplan-Meier method. A univariate Cox proportional hazard model was used to assess factors associated with recurrence. Results: Local and distant failure rates (as the first site of failure) at 2, 3, and 5 years were 33%, 33%, and 46%; and 26%, 26%, and 32%, respectively. The most common site ofmore » local failure was in the mediastinum; 12 of 18 local recurrences would have been included within proposed postoperative radiotherapy fields. Patients who received chemotherapy were found to be at increased risk of local failure, whereas those who underwent pneumonectomy or who had more positive nodes had significantly increased risks of distant failure. Conclusions: Patients with resected non-small-cell lung cancer who have N1 disease are at substantial risk of local recurrence as the first site of relapse, which is greater than the risk of distant failure. The role of postoperative radiotherapy in such patients should be revisited in the era of adjuvant chemotherapy.« less

Report of the Odyssey FPGA Independent Assessment Team

NASA Technical Reports Server (NTRS)

Mayer, Donald C.; Katz, Richard B.; Osborn, Jon V.; Soden, Jerry M.; Barto, R.; Day, John H. (Technical Monitor)

2001-01-01

An independent assessment team (IAT) was formed and met on April 2, 2001, at Lockheed Martin in Denver, Colorado, to aid in understanding a technical issue for the Mars Odyssey spacecraft scheduled for launch on April 7, 2001. An RP1280A field-programmable gate array (FPGA) from a lot of parts common to the SIRTF, Odyssey, and Genesis missions had failed on a SIRTF printed circuit board. A second FPGA from an earlier Odyssey circuit board was also known to have failed and was also included in the analysis by the IAT. Observations indicated an abnormally high failure rate for flight RP1280A devices (the first flight lot produced using this flow) at Lockheed Martin and the causes of these failures were not determined. Standard failure analysis techniques were applied to these parts, however, additional diagnostic techniques unique for devices of this class were not used, and the parts were prematurely submitted to a destructive physical analysis, making a determination of the root cause of failure difficult. Any of several potential failure scenarios may have caused these failures, including electrostatic discharge, electrical overstress, manufacturing defects, board design errors, board manufacturing errors, FPGA design errors, or programmer errors. Several of these mechanisms would have relatively benign consequences for disposition of the parts currently installed on boards in the Odyssey spacecraft if established as the root cause of failure. However, other potential failure mechanisms could have more dire consequences. As there is no simple way to determine the likely failure mechanisms with reasonable confidence before Odyssey launch, it is not possible for the IAT to recommend a disposition for the other parts on boards in the Odyssey spacecraft based on sound engineering principles.

A Case Study on Improving Intensive Care Unit (ICU) Services Reliability: By Using Process Failure Mode and Effects Analysis (PFMEA)

PubMed Central

Yousefinezhadi, Taraneh; Jannesar Nobari, Farnaz Attar; Goodari, Faranak Behzadi; Arab, Mohammad

2016-01-01

Introduction: In any complex human system, human error is inevitable and shows that can’t be eliminated by blaming wrong doers. So with the aim of improving Intensive Care Units (ICU) reliability in hospitals, this research tries to identify and analyze ICU’s process failure modes at the point of systematic approach to errors. Methods: In this descriptive research, data was gathered qualitatively by observations, document reviews, and Focus Group Discussions (FGDs) with the process owners in two selected ICUs in Tehran in 2014. But, data analysis was quantitative, based on failures’ Risk Priority Number (RPN) at the base of Failure Modes and Effects Analysis (FMEA) method used. Besides, some causes of failures were analyzed by qualitative Eindhoven Classification Model (ECM). Results: Through FMEA methodology, 378 potential failure modes from 180 ICU activities in hospital A and 184 potential failures from 99 ICU activities in hospital B were identified and evaluated. Then with 90% reliability (RPN≥100), totally 18 failures in hospital A and 42 ones in hospital B were identified as non-acceptable risks and then their causes were analyzed by ECM. Conclusions: Applying of modified PFMEA for improving two selected ICUs’ processes reliability in two different kinds of hospitals shows that this method empowers staff to identify, evaluate, prioritize and analyze all potential failure modes and also make them eager to identify their causes, recommend corrective actions and even participate in improving process without feeling blamed by top management. Moreover, by combining FMEA and ECM, team members can easily identify failure causes at the point of health care perspectives. PMID:27157162

Periodontitis in Chronic Heart Failure

PubMed Central

Fröhlich, Hanna; Herrmann, Kristina; Franke, Jennifer; Karimi, Alamara; Täger, Tobias; Cebola, Rita; Katus, Hugo A.; Zugck, Christian

2016-01-01

Periodontal disease has been associated with an increased risk of cardiovascular events. The purpose of our study was to investigate whether a correlation between periodontitis and chronic heart failure exists, as well as the nature of the underlying cause. We enrolled 71 patients (mean age, 54 ± 13 yr; 56 men) who had stable chronic heart failure; all underwent complete cardiologic and dental evaluations. The periodontal screening index was used to quantify the degree of periodontal disease. We compared the findings to those in the general population with use of data from the 4th German Dental Health Survey. Gingivitis, moderate periodontitis, and severe periodontitis were present in 17 (24%), 17 (24%), and 37 (52%) patients, respectively. Severe periodontitis was more prevalent among chronic heart failure patients than in the general population. In contrast, moderate periodontitis was more prevalent in the general population (P <0.00001). The severity of periodontal disease was not associated with the cause of chronic heart failure or the severity of heart failure symptoms. Six-minute walking distance was the only independent predictor of severe periodontitis. Periodontal disease is highly prevalent in chronic heart failure patients regardless of the cause of heart failure. Prospective trials are warranted to clarify the causal relationship between both diseases. PMID:27547136

Toward self-consistent tectono-magmatic numerical model of rift-to-ridge transition

NASA Astrophysics Data System (ADS)

Gerya, Taras; Bercovici, David; Liao, Jie

2017-04-01

Natural data from modern and ancient lithospheric extension systems suggest three-dimensional (3D) character of deformation and complex relationship between magmatism and tectonics during the entire rift-to-ridge transition. Therefore, self-consistent high-resolution 3D magmatic-thermomechanical numerical approaches stand as a minimum complexity requirement for modeling and understanding of this transition. Here we present results from our new high-resolution 3D finite-difference marker-in-cell rift-to-ridge models, which account for magmatic accretion of the crust and use non-linear strain-weakened visco-plastic rheology of rocks that couples brittle/plastic failure and ductile damage caused by grain size reduction. Numerical experiments suggest that nucleation of rifting and ridge-transform patterns are decoupled in both space and time. At intermediate stages, two patterns can coexist and interact, which triggers development of detachment faults, failed rift arms, hyper-extended margins and oblique proto-transforms. En echelon rift patterns typically develop in the brittle upper-middle crust whereas proto-ridge and proto-transform structures nucleate in the lithospheric mantle. These deep proto-structures propagate upward, inter-connect and rotate toward a mature orthogonal ridge-transform patterns on the timescale of millions years during incipient thermal-magmatic accretion of the new oceanic-like lithosphere. Ductile damage of the extending lithospheric mantle caused by grain size reduction assisted by Zenner pinning plays critical role in rift-to-ridge transition by stabilizing detachment faults and transform structures. Numerical results compare well with observations from incipient spreading regions and passive continental margins.

Defect reduction for semiconductor memory applications using jet and flash imprint lithography

NASA Astrophysics Data System (ADS)

Ye, Zhengmao; Luo, Kang; Irving, J. W.; Lu, Xiaoming; Zhang, Wei; Fletcher, Brian; Liu, Weijun; Xu, Frank; LaBrake, Dwayne; Resnick, Douglas; Sreenivasan, S. V.

2013-03-01

Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Jet and Flash Imprint Lithography (J-FIL) involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed leaving a patterned resist on the substrate. Acceptance of imprint lithography for manufacturing will require demonstration that it can attain defect levels commensurate with the defect specifications of high end memory devices. Typical defectivity targets are on the order of 0.10/cm2. In previous studies, we have focused on defects such as random non-fill defects occurring during the resist filling process and repeater defects caused by interactions with particles on the substrate. In this work, we attempted to identify the critical imprint defect types using a mask with NAND Flash-like patterns at dimensions as small as 26nm. The two key defect types identified were line break defects induced by small particulates and airborne contaminants which result in local adhesion failure. After identification, the root cause of the defect was determined, and corrective measures were taken to either eliminate or reduce the defect source. As a result, we have been able to reduce defectivity levels by more than three orders of magnitude in only 12 months and are now achieving defectivity adders as small as 2 adders per lot of wafers.

Renal failure in a patient with postpolio syndrome and a normal creatinine level.

PubMed

Leming, Melissa K; Breyer, Michael J

2012-01-01

Patients with renal failure who are taking trimethoprim have an increased risk of developing hyperkalemia, which can cause muscle weakness. In patients with postpolio syndrome, a normal creatinine level could be abnormally high, renal failure is possible because of lack of creatinine production, and the muscle weakness from resultant hyperkalemia could be more severe because of their underlying condition. This abnormally high creatinine level has been termed from this point relative renal failure. The objective of the study was to review a case in which relative renal failure and hyperkalemia caused muscle weakness that manifested as shortness of breath and confusion with electrocardiographic changes. A dehydrated patient with relative renal failure and postpolio syndrome had taken trimethoprim-sulfamethoxazole that caused symptomatic hyperkalemia. The patient presented with muscle weakness, shortness of breath, and confusion, with her postpolio syndrome compounding the situation and likely making the muscle weakness more severe. A patient on trimethoprim with renal failure is at an increased risk of developing hyperkalemia. Patients with postpolio syndrome could have severe muscle weakness from the hyperkalemia and could have renal failure even with a normal creatinine level. This case report will remind treating physicians to evaluate such patients for hyperkalemia if they present with muscle weakness, especially if the patient has renal failure and is on trimethoprim. Copyright © 2012 Elsevier Inc. All rights reserved.

Heart Failure

MedlinePlus

Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Heart failure does not mean that your heart has stopped ... and shortness of breath Common causes of heart failure are coronary artery disease, high blood pressure and ...

Temporal Lobe Epilepsy Surgery Failures: A Review

PubMed Central

Harroud, Adil; Bouthillier, Alain; Weil, Alexander G.; Nguyen, Dang Khoa

2012-01-01

Patients with temporal lobe epilepsy (TLE) are refractory to antiepileptic drugs in about 30% of cases. Surgical treatment has been shown to be beneficial for the selected patients but fails to provide a seizure-free outcome in 20–30% of TLE patients. Several reasons have been identified to explain these surgical failures. This paper will address the five most common causes of TLE surgery failure (a) insufficient resection of epileptogenic mesial temporal structures, (b) relapse on the contralateral mesial temporal lobe, (c) lateral temporal neocortical epilepsy, (d) coexistence of mesial temporal sclerosis and a neocortical lesion (dual pathology); and (e) extratemporal lobe epilepsy mimicking TLE or temporal plus epilepsy. Persistence of epileptogenic mesial structures in the posterior temporal region and failure to distinguish mesial and lateral temporal epilepsy are possible causes of seizure persistence after TLE surgery. In cases of dual pathology, failure to identify a subtle mesial temporal sclerosis or regions of cortical microdysgenesis is a likely explanation for some surgical failures. Extratemporal epilepsy syndromes masquerading as or coexistent with TLE result in incomplete resection of the epileptogenic zone and seizure relapse after surgery. In particular, the insula may be an important cause of surgical failure in patients with TLE. PMID:22934162

Resilience Design Patterns: A Structured Approach to Resilience at Extreme Scale

DOE PAGES

Engelmann, Christian; Hukerikar, Saurabh

2017-09-01

Reliability is a serious concern for future extreme-scale high-performance computing (HPC) systems. Projections based on the current generation of HPC systems and technology roadmaps suggest the prevalence of very high fault rates in future systems. While the HPC community has developed various resilience solutions, application-level techniques as well as system-based solutions, the solution space remains fragmented. There are no formal methods and metrics to integrate the various HPC resilience techniques into composite solutions, nor are there methods to holistically evaluate the adequacy and efficacy of such solutions in terms of their protection coverage, and their performance \\& power efficiency characteristics.more » Additionally, few of the current approaches are portable to newer architectures and software environments that will be deployed on future systems. In this paper, we develop a structured approach to the design, evaluation and optimization of HPC resilience using the concept of design patterns. A design pattern is a general repeatable solution to a commonly occurring problem. We identify the problems caused by various types of faults, errors and failures in HPC systems and the techniques used to deal with these events. Each well-known solution that addresses a specific HPC resilience challenge is described in the form of a pattern. We develop a complete catalog of such resilience design patterns, which may be used by system architects, system software and tools developers, application programmers, as well as users and operators as essential building blocks when designing and deploying resilience solutions. We also develop a design framework that enhances a designer's understanding the opportunities for integrating multiple patterns across layers of the system stack and the important constraints during implementation of the individual patterns. It is also useful for defining mechanisms and interfaces to coordinate flexible fault management across hardware and software components. The resilience patterns and the design framework also enable exploration and evaluation of design alternatives and support optimization of the cost-benefit trade-offs among performance, protection coverage, and power consumption of resilience solutions. Here, the overall goal of this work is to establish a systematic methodology for the design and evaluation of resilience technologies in extreme-scale HPC systems that keep scientific applications running to a correct solution in a timely and cost-efficient manner despite frequent faults, errors, and failures of various types.« less

Resilience Design Patterns: A Structured Approach to Resilience at Extreme Scale

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelmann, Christian; Hukerikar, Saurabh

Reliability is a serious concern for future extreme-scale high-performance computing (HPC) systems. Projections based on the current generation of HPC systems and technology roadmaps suggest the prevalence of very high fault rates in future systems. While the HPC community has developed various resilience solutions, application-level techniques as well as system-based solutions, the solution space remains fragmented. There are no formal methods and metrics to integrate the various HPC resilience techniques into composite solutions, nor are there methods to holistically evaluate the adequacy and efficacy of such solutions in terms of their protection coverage, and their performance \\& power efficiency characteristics.more » Additionally, few of the current approaches are portable to newer architectures and software environments that will be deployed on future systems. In this paper, we develop a structured approach to the design, evaluation and optimization of HPC resilience using the concept of design patterns. A design pattern is a general repeatable solution to a commonly occurring problem. We identify the problems caused by various types of faults, errors and failures in HPC systems and the techniques used to deal with these events. Each well-known solution that addresses a specific HPC resilience challenge is described in the form of a pattern. We develop a complete catalog of such resilience design patterns, which may be used by system architects, system software and tools developers, application programmers, as well as users and operators as essential building blocks when designing and deploying resilience solutions. We also develop a design framework that enhances a designer's understanding the opportunities for integrating multiple patterns across layers of the system stack and the important constraints during implementation of the individual patterns. It is also useful for defining mechanisms and interfaces to coordinate flexible fault management across hardware and software components. The resilience patterns and the design framework also enable exploration and evaluation of design alternatives and support optimization of the cost-benefit trade-offs among performance, protection coverage, and power consumption of resilience solutions. Here, the overall goal of this work is to establish a systematic methodology for the design and evaluation of resilience technologies in extreme-scale HPC systems that keep scientific applications running to a correct solution in a timely and cost-efficient manner despite frequent faults, errors, and failures of various types.« less

Common Cause Failure Modes

NASA Technical Reports Server (NTRS)

Wetherholt, Jon; Heimann, Timothy J.; Anderson, Brenda

2011-01-01

High technology industries with high failure costs commonly use redundancy as a means to reduce risk. Redundant systems, whether similar or dissimilar, are susceptible to Common Cause Failures (CCF). CCF is not always considered in the design effort and, therefore, can be a major threat to success. There are several aspects to CCF which must be understood to perform an analysis which will find hidden issues that may negate redundancy. This paper will provide definition, types, a list of possible causes and some examples of CCF. Requirements and designs from NASA projects will be used in the paper as examples.

Heart failure caused by toxoplasmosis in a fennec fox (Fennecus zerda).

PubMed

Kottwitz, Jack J; Preziosi, Diane E; Miller, Margaret A; Ramos-Vara, Jose A; Maggs, David J; Bonagura, John D

2004-01-01

A male fennec fox (Fennecus zerda) kit was examined for lethargy, inappetence, and weight loss. Clinical findings included respiratory distress, a gallop rhythm, and retinochoroiditis. Radiography indicated pleural effusion and cardiomegaly. Echocardiographic findings included left ventricular dilatation, low left ventricular ejection fraction, and atrioventricular valvular regurgitation. Necropsy findings were compatible with a diagnosis of congestive heart failure caused by myocarditis. Histopathology showed a disseminated infection with Toxoplasma gondii causing myocarditis, skeletal polymyositis, gastrointestinal myositis, and panuveitis. Toxoplasma-induced myocarditis should be included in the differential diagnosis of heart failure and retinochoroiditis in the fennec fox.

Scrub typhus causing neonatal hepatitis with acute liver failure-A case series.

PubMed

Vajpayee, Shailja; Gupta, R K; Gupta, M L

2017-05-01

Neonatal hepatitis with acute liver failure due to varied etiology including various infections is reported in the past. Scrub typhus as a cause of neonatal hepatitis has rarely been reported in literature. A high index of clinical suspicion is required for early diagnosis and timely treatment. Severity and prognosis of the disease varies widely because several different strains of Orientia tsutsugamushi exist with different virulence. Delayed diagnosis can result in complication and significant morbidity and mortality. Here, we report three cases of neonatal hepatitis with acute liver failure caused by scrub typhus to increase awareness.

Common Cause Failure Modeling in Space Launch Vehicles

NASA Technical Reports Server (NTRS)

Hark, Frank; Ring, Rob; Novack, Steven D.; Britton, Paul

2015-01-01

Common Cause Failures (CCFs) are a known and documented phenomenon that defeats system redundancy. CCFs are a set of dependent type of failures that can be caused for example by system environments, manufacturing, transportation, storage, maintenance, and assembly. Since there are many factors that contribute to CCFs, they can be reduced, but are difficult to eliminate entirely. Furthermore, failure databases sometimes fail to differentiate between independent and dependent CCF. Because common cause failure data is limited in the aerospace industry, the Probabilistic Risk Assessment (PRA) Team at Bastion Technology Inc. is estimating CCF risk using generic data collected by the Nuclear Regulatory Commission (NRC). Consequently, common cause risk estimates based on this database, when applied to other industry applications, are highly uncertain. Therefore, it is important to account for a range of values for independent and CCF risk and to communicate the uncertainty to decision makers. There is an existing methodology for reducing CCF risk during design, which includes a checklist of 40+ factors grouped into eight categories. Using this checklist, an approach to produce a beta factor estimate is being investigated that quantitatively relates these factors. In this example, the checklist will be tailored to space launch vehicles, a quantitative approach will be described, and an example of the method will be presented.

The movement and deposition of PM2.5 in the upper respiratory tract for the patients with heart failure: an elementary CFD study.

PubMed

Zhang, Tiantian; Gao, Bin; Zhou, Zhixiang; Chang, Yu

2016-12-28

PM2.5 is an important factor to affect the patients with respiratory and cardiovascular diseases. Clinical studies have found that the morbidity and mortality of patients with heart failure (HF) have a close relationship with the movement and deposition state of PM2.5. One reason is that the breathing pattern of patients with HF has obvious difference with healthy people, however the effect caused by these differences on the distribution regularity of PM2.5 in the respiratory tract is still unclear. Hence, a computational fluid dynamics simulation was conducted to clarify the aerodynamic effect of breathing pattern of patients with HF on respiratory system. Ideal upper respiratory tract geometric model was established based on standardized aerosol research laboratory of Alberta and Weibel A dimension. The discrete phase method is used to calculate the movement of the airflow and particles. The flow rate were chosen as the inlet boundary conditions, and the outlets are set at a constant pressure. The rate of particle deposition, distribution location, wall pressure, flow velocity and wall shear stress are obtained, and compared to the normal control. The results demonstrated that the rate of escaped particles in every bronchial outlet of the patients with HF was more than the normal controls, meanwhile the trapped was less (1024 < 1160). There was higher by 12.9% possibility that the PM2.5 entered the lungs than the normal control. The aerodynamic performances of HF patients are different from normal control. Compared to the normal control, under similar environment, there is higher possibility of PM2.5 moving into lungs, and these particles could affect the function of the respiratory system, resulting in the deterioration of the state of cardiovascular system. In short, it's necessary to pay more attention to the living environment of HF patients, to reduce the content of PM2.5 particles in the air, and reduce the damage of PM2.5 particles caused by breathing patterns.

Apollo 15 main-parachute failure

NASA Technical Reports Server (NTRS)

Arabian, D. D.; Mechelay, J. E.

1972-01-01

In the investigation of the failure of one of the three main parachutes of the Apollo 15 spacecraft, which collapsed at approximately 1825 meters after operating properly from deployment at 3050 meters, three conditions considered to be possible causes of the failure were produced. The suspect conditions were the proximity of the forward heat shield that passed the spacecraft at approximately 1825 meters, the dumping of the reaction control system hypergolic propellants at approximately 1825 meters, and the failing of a riser link found on a recovered parachute. (The failed parachute was not recovered). The remaining two parachutes functioned as planned and averted a catastrophic failure. The conclusions concerning the cause of the failure are discussed.

Hypokalemic muscular paralysis causing acute respiratory failure due to rhabdomyolysis with renal tubular acidosis in a chronic glue sniffer.

PubMed

Kao, K C; Tsai, Y H; Lin, M C; Huang, C C; Tsao, C Y; Chen, Y C

2000-01-01

A 34-year-old male was admitted to the emergency department with the development of quadriparesis and respiratory failure due to hypokalemia after prolonged glue sniffing. The patient was subsequently given mechanical ventilatory support for respiratory failure. He was weaned from the ventilator 4 days later after potassium replacement. Toluene is an aromatic hydrocarbon found in glues, cements, and solvents. It is known to be toxic to the nervous system, hematopoietic system, and causes acid-base and electrolyte disorders. Acute respiratory failure with hypokalemia and rhabdomyolysis with acute renal failure should be considered as potential events in a protracted glue sniffing.

236 children with developmental hydrocephalus: causes and clinical consequences

PubMed Central

Tully, Hannah M; Ishak, Gisele E; Rue, Tessa C; Dempsey, Jennifer C; Browd, Samuel R; Millen, Kathleen J; Doherty, Dan; Dobyns, William B

2016-01-01

Few systematic assessments of developmental forms of hydrocephalus exist. We reviewed MRIs and clinical records of patients with infancy-onset hydrocephalus. Among 411 infants, 236 had hydrocephalus with no recognizable extrinsic cause. These children were assigned to one of five subtypes and compared on the basis of clinical characteristics, developmental and surgical outcomes. At an average age of 5.3 years, 72% of children were walking independently and 87% could eat by mouth. 18% had epilepsy. Distinct patterns of associated malformations and syndromes were observed within each subtype. On average, children with aqueductal obstruction, cysts and encephaloceles had worse clinical outcomes than those with other forms of developmental hydrocephalus. 53% of surgically-treated patients experienced at least one shunt failure, but hydrocephalus associated with posterior fossa crowding required fewer shunt revisions. We conclude that each subtype of developmental hydrocephalus is associated with distinct clinical characteristics, syndromology, and outcomes, suggesting differences in underlying mechanisms. PMID:26184484

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rimner, Andreas, E-mail: rimnera@mskcc.org; Spratt, Daniel E.; Zauderer, Marjorie G.

Purpose: We previously reported our technique for delivering intensity modulated radiation therapy (IMRT) to the entire pleura while attempting to spare the lung in patients with malignant pleural mesothelioma (MPM). Herein, we report a detailed pattern-of-failure analysis in patients with MPM who were unresectable or underwent pleurectomy/decortication (P/D), uniformly treated with hemithoracic pleural IMRT. Methods and Materials: Sixty-seven patients with MPM were treated with definitive or adjuvant hemithoracic pleural IMRT between November 2004 and May 2013. Pretreatment imaging, treatment plans, and posttreatment imaging were retrospectively reviewed to determine failure location(s). Failures were categorized as in-field (within the 90% isodose line),more » marginal (<90% and ≥50% isodose lines), out-of-field (outside the 50% isodose line), or distant. Results: The median follow-up was 24 months from diagnosis and the median time to in-field local failure from the end of RT was 10 months. Forty-three in-field local failures (64%) were found with a 1- and 2-year actuarial failure rate of 56% and 74%, respectively. For patients who underwent P/D versus those who received a partial pleurectomy or were deemed unresectable, the median time to in-field local failure was 14 months versus 6 months, respectively, with 1- and 2-year actuarial in-field local failure rates of 43% and 60% versus 66% and 83%, respectively (P=.03). There were 13 marginal failures (19%). Five of the marginal failures (38%) were located within the costomediastinal recess. Marginal failures decreased with increasing institutional experience (P=.04). Twenty-five patients (37%) had out-of-field failures. Distant failures occurred in 32 patients (48%). Conclusions: After hemithoracic pleural IMRT, local failure remains the dominant form of failure pattern. Patients treated with adjuvant hemithoracic pleural IMRT after P/D experience a significantly longer time to local and distant failure than patients treated with definitive pleural IMRT. Increasing experience and improvement in target delineation minimize the incidence of avoidable marginal failures.« less

Management of failure after surgery for gastro-esophageal reflux disease.

PubMed

Gronnier, C; Degrandi, O; Collet, D

2018-04-01

Surgical treatment of gastro-esophageal reflux disease (ST-GERD) is well-codified and offers an alternative to long-term medical treatment with a better efficacy for short and long-term outcomes. However, failure of ST-GERD is observed in 2-20% of patients; management is challenging and not standardized. The aim of this study is to analyze the causes of failure and to provide a treatment algorithm. The clinical aspects of ST-GERD failure are variable including persistent reflux, dysphagia or permanent discomfort leading to an important degradation of the quality of life. A morphological and functional pre-therapeutic evaluation is necessary to: (i) determine whether the symptoms are due to recurrence of reflux or to an error in initial indication and (ii) to understand the cause of the failure. The most frequent causes of failure of ST-GERD include errors in the initial indication, which often only need medical treatment, and surgical technical errors, for which surgical redo surgery can be difficult. Multidisciplinary management is necessary in order to offer the best-adapted treatment. Copyright © 2018. Published by Elsevier Masson SAS.

Independent Review Support for Phoenix Mars Mission Robotic Arm Brush Motor Failure

NASA Technical Reports Server (NTRS)

McManamen, John P.; Pellicciotti, Joseph; DeKramer, Cornelis; Dube, Michael J.; Peeler, Deborah; Muirhead, Brian K.; Sevilla, Donald R.; Sabahi, Dara; Knopp, Michael D.

2007-01-01

The Phoenix Project requested the NASA Engineering and Safety Center (NESC) perform an independent peer review of the Robotic Arm (RA) Direct Current (DC) motor brush anomalies that originated during the Mars Exploration Rover (MER) Project and recurred during the Phoenix Project. The request was to evaluate the Phoenix Project investigation efforts and provide an independent risk assessment. This includes a recommendation for additional work and assessment of the flight worthiness of the RA DC motors. Based on the investigation and findings contained within this report, the IRT concurs with the risk assessment Failure Cause / Corrective Action (FC/CA) by the project, "Failure Effect Rating "3"; Major Degradation or Total Loss of Function, Failure Cause/Corrective Action Rating Currently "4"; Unknown Cause, Uncertainty in Corrective Action."

Failure-Avoidance: Parenting, the Achievement Environment of the Home and Strategies for Reduction

ERIC Educational Resources Information Center

Thompson, Ted

2004-01-01

This paper draws together the as yet nascent literature on the development of failure-avoidant patterns of behaviour. These are behaviours intended to minimise risk to self-worth in the event of failure, thereby avoiding the negative impact of poor performance in terms of damage to self-worth. Self-worth protection, self-handicapping, impostor…

The Medial Stitch in Transosseous-Equivalent Rotator Cuff Repair: Vertical or Horizontal Mattress?

PubMed

Montanez, Anthony; Makarewich, Christopher A; Burks, Robert T; Henninger, Heath B

2016-09-01

Despite advances in surgical technique, rotator cuff repair retears continue to occur at rates of 10%, 22%, and 57% for small, medium, and large tears, respectively. A common mode of failure in transosseous-equivalent rotator cuff repairs is tissue pullout of the medial mattress stitch. While the medial mattress stitch has been studied extensively, no studies have evaluated a vertical mattress pattern placed near the musculotendinous junction in comparison with a horizontal mattress pattern. Vertical mattress stitches will have higher load to failure and lower gapping compared with horizontal mattress stitches in a transosseous-equivalent rotator cuff repair. Controlled laboratory study. Double-row transosseous-equivalent rotator cuff repairs were performed in 9 pairs of human male cadaveric shoulders (mean age ± SD, 58 ± 10 years). One shoulder in each pair received a medial-row suture pattern using a vertical mattress stitch, and the contralateral shoulder received a horizontal mattress. Specimens were mounted in a materials testing machine and tested in uniaxial tensile deformation for cyclic loading (500 cycles at 1 Hz to 1.0 MPa of effective stress), followed by failure testing carried out at a rate of 1 mm/s. Construct gapping and applied loads were monitored continuously throughout the testing. Vertical mattress sutures were placed in 5 right and 4 left shoulders. Peak cyclic gapping did not differ between vertical (mean ± SD, 2.8 ± 1.1 mm) and horizontal mattress specimens (3.0 ± 1.2 mm) (P = .684). Vertical mattress sutures failed at higher loads compared with horizontal mattress sutures (568.9 ± 140.3 vs 451.1 ± 174.3 N; P = .025); however, there was no significant difference in failure displacement (8.0 ± 1.6 vs 6.0 ± 2.1 mm; P = .092). Failure stiffness did not differ between the suture patterns (P = .204). In transosseous-equivalent rotator cuff repairs near the musculotendinous junction, a vertical mattress suture used as the medial stitch has a higher load to failure but no difference in gapping compared with a horizontal mattress pattern. A vertical mattress suture may offer enhanced strength of repair for transosseous-equivalent repairs. © 2016 The Author(s).

A Comparative Finite-Element Analysis of Bone Failure and Load Transfer of Osseointegrated Prostheses Fixations

PubMed Central

Tomaszewski, P. K.; Verdonschot, N.; Bulstra, S. K.

2010-01-01

An alternative solution to conventional stump–socket prosthetic limb attachment is offered by direct skeletal fixation. This study aimed to assess two percutaneous trans-femoral implants, the OPRA system (Integrum AB, Göteborg, Sweden), and the ISP Endo/Exo prosthesis (ESKA Implants AG, Lübeck, Germany) on bone failure and stem–bone interface mechanics both early post-operative (before bony ingrowth) and after full bone ingrowth. Moreover, mechanical consequences of implantation of those implants in terms of changed loading pattern within the bone and potential consequences on long-term bone remodeling were studied using finite-element models that represent the intact femur and implants fitted in amputated femora. Two experimentally measured loads from the normal walking cycle were applied. The analyses revealed that implantation of percutaneous prostheses had considerable effects on stress and strain energy density levels in bone. This was not only caused by the implant itself, but also by changed loading conditions in the amputated leg. The ISP design promoted slightly more physiological strain energy distribution (favoring long-term bone maintenance), but the OPRA design generated lower bone stresses (reducing bone fracture risk). The safety factor against mechanical failure of the two percutaneous designs was relatively low, which could be improved by design optimization of the implants. PMID:20309731

Leveraging Client-Side DNS Failure Patterns to Identify Malicious Behaviors

DTIC Science & Technology

2015-09-28

malicious behavior found in our dataset and (ii) to create ground truth to evaluate the system proposed in Section V. We begin by removing those cases that...2011. [10] S. Hao, N. Feamster, and R. Pandrangi, “Monitoring the Initial DNS Behavior of Malicious Domains,” in ACM IMC , 2011. [11] R. Perdisci et...distribution is unlimited. Leveraging Client-Side DNS Failure Patterns to Identify Malicious Behaviors The views, opinions and/or findings contained in

45 CFR 262.5 - Under what general circumstances will we determine that a State has reasonable cause?

Code of Federal Regulations, 2014 CFR

2014-10-01

... State if we determine that the State had reasonable cause for its failure. The general factors a State...., hurricanes, earthquakes, fire) whose disruptive impact was so significant as to cause the State's failure; (2... (3) Isolated problems of minimal impact that are not indicative of a systemic problem. (b)(1) We will...

Antimicrobial treatment failures in patients with community-acquired pneumonia: causes and prognostic implications.

PubMed

Arancibia, F; Ewig, S; Martinez, J A; Ruiz, M; Bauer, T; Marcos, M A; Mensa, J; Torres, A

2000-07-01

The aim of the study was to determine the causes and prognostic implications of antimicrobial treatment failures in patients with nonresponding and progressive life-threatening, community-acquired pneumonia. Forty-nine patients hospitalized with a presumptive diagnosis of community-acquired pneumonia during a 16-mo period, failure to respond to antimicrobial treatment, and documented repeated microbial investigation >/= 72 h after initiation of in-hospital antimicrobial treatment were recorded. A definite etiology of treatment failure could be established in 32 of 49 (65%) patients, and nine additional patients (18%) had a probable etiology. Treatment failures were mainly infectious in origin and included primary, persistent, and nosocomial infections (n = 10 [19%], 13 [24%], and 11 [20%] of causes, respectively). Definite but not probable persistent infections were mostly due to microbial resistance to the administered initial empiric antimicrobial treatment. Nosocomial infections were particularly frequent in patients with progressive pneumonia. Definite persistent infections and nosocomial infections had the highest associated mortality rates (75 and 88%, respectively). Nosocomial pneumonia was the only cause of treatment failure independently associated with death in multivariate analysis (RR, 16.7; 95% CI, 1.4 to 194.9; p = 0.03). We conclude that the detection of microbial resistance and the diagnosis of nosocomial pneumonia are the two major challenges in hospitalized patients with community-acquired pneumonia who do not respond to initial antimicrobial treatment. In order to establish these potentially life-threatening etiologies, a regular microbial reinvestigation seems mandatory for all patients presenting with antimicrobial treatment failures.

Intravenous Milrinone Infusion Improves Congestive Heart Failure Caused by Diastolic Dysfunction

PubMed Central

Albrecht, Carlos A.; Giesler, Gregory M.; Kar, Biswajit; Hariharan, Ramesh; Delgado, Reynolds M.

2005-01-01

Although there have been significant advances in the medical treatment of heart failure patients with impaired systolic function, very little is known about the diagnosis and treatment of diastolic dysfunction. We report the cases of 3 patients in New York Heart Association functional class IV who had echocardiographically documented diastolic dysfunction as the main cause of heart failure. All 3 patients received medical therapy with long-term milrinone infusion. PMID:16107121

Comparison of crude and adjusted mortality rates from leading causes of death in northeastern Brazil.

PubMed

França, Elisabeth; Rao, Chalapati; Abreu, Daisy Maria Xavier de; Souza, Maria de Fátima Marinho de; Lopez, Alan D

2012-04-01

To present how the adjustment of incompleteness and misclassification of causes of death in the vital registration (VR) system can contribute to more accurate estimates of the risk of mortality from leading causes of death in northeastern Brazil. After estimating the total numbers of deaths by age and sex in Brazil's Northeast region in 2002-2004 by correcting for undercount in the VR data, adjustment algorithms were applied to the reported cause-of-death structure. Average annual age-standardized mortality rates were computed by cause, with and without the corrections, and compared to death rates for Brazil's South region after adjustments for potential misdiagnosis. Death rates from ischemic heart disease, lower respiratory infections, chronic obstructive pulmonary disease, and perinatal conditions were more than 100% higher for both sexes than what was suggested by the routine VR data. Corrected cause-specific mortality rates were higher in the Northeast region versus the South region for the majority of causes of death, including several noncommunicable conditions. Failure to adjust VR data for undercount of cases reported and misdiagnoses will cause underestimation of mortality risks for the populations of the Northeast region, which are more vulnerable than those in other regions of the country. In order to more reliably understand the pattern of disease, all cause-specific mortality rates in poor populations should be adjusted.

Snow fracture: From micro-cracking to global failure

NASA Astrophysics Data System (ADS)

Capelli, Achille; Reiweger, Ingrid; Schweizer, Jürg

2017-04-01

Slab avalanches are caused by a crack forming and propagating in a weak layer within the snow cover, which eventually causes the detachment of the overlying cohesive slab. The gradual damage process leading to the nucleation of the initial failure is still not entirely understood. Therefore, we studied the damage process preceding snow failure by analyzing the acoustic emissions (AE) generated by bond failure or micro-cracking. The AE allow studying the ongoing progressive failure in a non-destructive way. We performed fully load-controlled failure experiments on snow samples presenting a weak layer and recorded the generated AE. The size and frequency of the generated AE increased before failure revealing an acceleration of the damage process with increased size and frequency of damage and/or microscopic cracks. The AE energy was power-law distributed and the exponent (b-value) decreased approaching failure. The waiting time followed an exponential distribution with increasing exponential coefficient λ before failure. The decrease of the b-value and the increase of λ correspond to a change in the event distribution statistics indicating a transition from homogeneously distributed uncorrelated damage producing mostly small AE to localized damage, which cause larger correlated events which leads to brittle failure. We observed brittle failure for the fast experiment and a more ductile behavior for the slow experiments. This rate dependence was reflected also in the AE signature. In the slow experiments the b value and λ were almost constant, and the energy rate increase was moderate indicating that the damage process was in a stable state - suggesting the damage and healing processes to be balanced. On a shorter time scale, however, the AE parameters varied indicating that the damage process was not steady but consisted of a sum of small bursts. We assume that the bursts may have been generated by cascades of correlated micro-cracks caused by localization of stresses at a small scale. The healing process may then have prevented the self-organization of this small scale damage and, therefore, the total failure of the sample.

Underlying Cause(s) of Letter Perseveration Errors

PubMed Central

Fischer-Baum, Simon; Rapp, Brenda

2011-01-01

Perseverations, the inappropriate intrusion of elements from a previous response into a current response, are commonly observed in individuals with acquired deficits. This study specifically investigates the contribution of failure-to activate and failure-to-inhibit deficit(s) in the generation of letter perseveration errors in acquired dysgraphia. We provide evidence from the performance 12 dysgraphic individuals indicating that a failure to activate graphemes for a target word gives rise to letter perseveration errors. In addition, we also provide evidence that, in some individuals, a failure-to-inhibit deficit may also contribute to the production of perseveration errors. PMID:22178232

[Acute renal failure in a 75-year-old woman with a high-output ileostoma].

PubMed

Teege, S; Wiech, T; Steinmetz, O M

2017-05-01

We report on a 75-year old woman who presented with acute oliguric renal failure. The kidney biopsy revealed calcium oxalate depositions in the tubular lumen, caused by an overload of intravenous ascorbic acid (cumulative dose of 240 g). Due to a lack of specific therapeutic interventions, the patient remained dialysis-dependent. Iatrogenic causes of kidney failure play an important role in the pathogenesis of kidney diseases and should always be considered in patients with acute renal failure. Detailed evaluation of the patient history is often suggestive, while renal biopsy can establish the diagnosis.

Total artificial heart implantation for biventricular failure due to eosinophilic myocarditis.

PubMed

Kawabori, Masashi; Kurihara, Chitaru; Miller, Yair; Heck, Kent A; Bogaev, Roberta C; Civitello, Andrew B; Cohn, William E; Frazier, O H; Morgan, Jeffrey A

2017-09-01

Idiopathic hypereosinophilic syndrome is a condition of unknown etiology characterized by proliferation of eosinophils and their infiltration into tissues. Although cardiac involvement is rare, eosinophilic myocarditis can lead to life-threating fulminant congestive heart failure. Treatment of patients with eosinophilic myocarditis is challenging as heart failure can be caused by biventricular dysfunction. To our knowledge, this is the first case reported in the literature describing a patient with acute severe biventricular heart failure caused by eosinophilic myocarditis with mural left ventricular apical thrombus who was successfully treated with implantation of a total artificial heart as a bridge to heart transplant.

Techniques to evaluate the importance of common cause degradation on reliability and safety of nuclear weapons.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darby, John L.

2011-05-01

As the nuclear weapon stockpile ages, there is increased concern about common degradation ultimately leading to common cause failure of multiple weapons that could significantly impact reliability or safety. Current acceptable limits for the reliability and safety of a weapon are based on upper limits on the probability of failure of an individual item, assuming that failures among items are independent. We expanded the current acceptable limits to apply to situations with common cause failure. Then, we developed a simple screening process to quickly assess the importance of observed common degradation for both reliability and safety to determine if furthermore » action is necessary. The screening process conservatively assumes that common degradation is common cause failure. For a population with between 100 and 5000 items we applied the screening process and conclude the following. In general, for a reliability requirement specified in the Military Characteristics (MCs) for a specific weapon system, common degradation is of concern if more than 100(1-x)% of the weapons are susceptible to common degradation, where x is the required reliability expressed as a fraction. Common degradation is of concern for the safety of a weapon subsystem if more than 0.1% of the population is susceptible to common degradation. Common degradation is of concern for the safety of a weapon component or overall weapon system if two or more components/weapons in the population are susceptible to degradation. Finally, we developed a technique for detailed evaluation of common degradation leading to common cause failure for situations that are determined to be of concern using the screening process. The detailed evaluation requires that best estimates of common cause and independent failure probabilities be produced. Using these techniques, observed common degradation can be evaluated for effects on reliability and safety.« less

The standard deviation of extracellular water/intracellular water is associated with all-cause mortality and technique failure in peritoneal dialysis patients.

PubMed

Tian, Jun-Ping; Wang, Hong; Du, Feng-He; Wang, Tao

2016-09-01

The mortality rate of peritoneal dialysis (PD) patients is still high, and the predicting factors for PD patient mortality remain to be determined. This study aimed to explore the relationship between the standard deviation (SD) of extracellular water/intracellular water (E/I) and all-cause mortality and technique failure in continuous ambulatory PD (CAPD) patients. All 152 patients came from the PD Center between January 1st 2006 and December 31st 2007. Clinical data and at least five-visit E/I ratio defined by bioelectrical impedance analysis were collected. The patients were followed up till December 31st 2010. The primary outcomes were death from any cause and technique failure. Kaplan-Meier analysis and Cox proportional hazards models were used to identify risk factors for mortality and technique failure in CAPD patients. All patients were followed up for 59.6 ± 23.0 months. The patients were divided into two groups according to their SD of E/I values: lower SD of E/I group (≤0.126) and higher SD of E/I group (>0.126). The patients with higher SD of E/I showed a higher all-cause mortality (log-rank χ (2) = 10.719, P = 0.001) and technique failure (log-rank χ (2) = 9.724, P = 0.002) than those with lower SD of E/I. Cox regression analysis found that SD of E/I independently predicted all-cause mortality (HR  3.551, 95 % CI 1.442-8.746, P = 0.006) and technique failure (HR  2.487, 95 % CI 1.093-5.659, P = 0.030) in CAPD patients after adjustment for confounders except when sensitive C-reactive protein was added into the model. The SD of E/I was a strong independent predictor of all-cause mortality and technique failure in CAPD patients.

Automatic OPC repair flow: optimized implementation of the repair recipe

NASA Astrophysics Data System (ADS)

Bahnas, Mohamed; Al-Imam, Mohamed; Word, James

2007-10-01

Virtual manufacturing that is enabled by rapid, accurate, full-chip simulation is a main pillar in achieving successful mask tape-out in the cutting-edge low-k1 lithography. It facilitates detecting printing failures before a costly and time-consuming mask tape-out and wafer print occur. The OPC verification step role is critical at the early production phases of a new process development, since various layout patterns will be suspected that they might to fail or cause performance degradation, and in turn need to be accurately flagged to be fed back to the OPC Engineer for further learning and enhancing in the OPC recipe. At the advanced phases of the process development, there is much less probability of detecting failures but still the OPC Verification step act as the last-line-of-defense for the whole RET implemented work. In recent publication the optimum approach of responding to these detected failures was addressed, and a solution was proposed to repair these defects in an automated methodology and fully integrated and compatible with the main RET/OPC flow. In this paper the authors will present further work and optimizations of this Repair flow. An automated analysis methodology for root causes of the defects and classification of them to cover all possible causes will be discussed. This automated analysis approach will include all the learning experience of the previously highlighted causes and include any new discoveries. Next, according to the automated pre-classification of the defects, application of the appropriate approach of OPC repair (i.e. OPC knob) on each classified defect location can be easily selected, instead of applying all approaches on all locations. This will help in cutting down the runtime of the OPC repair processing and reduce the needed number of iterations to reach the status of zero defects. An output report for existing causes of defects and how the tool handled them will be generated. The report will with help further learning and facilitate the enhancement of the main OPC recipe. Accordingly, the main OPC recipe can be more robust, converging faster and probably in a fewer number of iterations. This knowledge feedback loop is one of the fruitful benefits of the Automatic OPC Repair flow.

Epidemiology and Clinical Characteristics of Acinetobacter Peritoneal Dialysis-Related Peritonitis in Hong Kong-With a Perspective on Multi-Drug and Carbapenem Resistance.

PubMed

Li, Philip Hei; Cheng, Vincent C C; Yip, Terence; Yap, Desmond Y H; Lui, Sing-Leung; Lo, Wai-Kei

2017-01-01

♦ BACKGROUND: Acinetobacter spp. is an important cause of peritoneal dialysis (PD)-related peritonitis, but studies on Acinetobacter peritonitis have been scarce. In view of the rising concern of carbapenem-resistant Acinetobacter (CRA) and multidrug-resistant Acinetobacter (MDRA) infections, we conducted this study on the incidence of Acinetobacter peritonitis and the impact of CRA and MDRA on its outcome. ♦ METHODS: We retrospectively evaluated the clinical characteristics, prevalence, antibiotic sensitivity patterns, outcomes, and factors associated with treatment failure over the past 16 years in our patients with Acinetobacter PD-related peritonitis. ♦ RESULTS: Out of 2,389 episodes of peritonitis, there were 66 episodes (3%) of Acinetobacter peritonitis occurring in 59 patients. Twelve episodes were caused by MDRA (18%), of which 5 were CRA (8%). There was a progressive increase in the incidence of MDRA and CRA infections over the study period. Most isolates were sensitive to sulbactam combinations (ampicillin-sulbactam [95.4%] and cefoperazone-sulbactam [93.9%]), aminoglycosides (amikacin [92.4%], tobramycin [90.9%], and gentamicin [89.4%]), and carbapenems (imipenem [92.2%]). There was 1 case of relapse. Fifteen episodes resulted in catheter removal (23%), and 7 patients died (11%). Hypoalbuminemia (odds ratio [OR] = 0.85, p = 0.006) and carbapenem resistance (OR = 18.2, p = 0.049) were significantly associated with higher rates of treatment failure. ♦ CONCLUSION: Both carbapenem resistance and hypoalbuminemia were significantly associated with treatment failure. Up to 80% of peritonitis episodes by CRA resulted in catheter loss or mortality. Sulbactam combinations and/or aminoglycosides remained effective for the majority of Acinetobacter isolates. There seemed to be an increasing relative incidence of MDRA and CRA infections over the past 16 years. Copyright © 2017 International Society for Peritoneal Dialysis.

A method for automatically optimizing medical devices for treating heart failure: designing polymeric injection patterns.

PubMed

Wenk, Jonathan F; Wall, Samuel T; Peterson, Robert C; Helgerson, Sam L; Sabbah, Hani N; Burger, Mike; Stander, Nielen; Ratcliffe, Mark B; Guccione, Julius M

2009-12-01

Heart failure continues to present a significant medical and economic burden throughout the developed world. Novel treatments involving the injection of polymeric materials into the myocardium of the failing left ventricle (LV) are currently being developed, which may reduce elevated myofiber stresses during the cardiac cycle and act to retard the progression of heart failure. A finite element (FE) simulation-based method was developed in this study that can automatically optimize the injection pattern of the polymeric "inclusions" according to a specific objective function, using commercially available software tools. The FE preprocessor TRUEGRID((R)) was used to create a parametric axisymmetric LV mesh matched to experimentally measured end-diastole and end-systole metrics from dogs with coronary microembolization-induced heart failure. Passive and active myocardial material properties were defined by a pseudo-elastic-strain energy function and a time-varying elastance model of active contraction, respectively, that were implemented in the FE software LS-DYNA. The companion optimization software LS-OPT was used to communicate directly with TRUEGRID((R)) to determine FE model parameters, such as defining the injection pattern and inclusion characteristics. The optimization resulted in an intuitive optimal injection pattern (i.e., the one with the greatest number of inclusions) when the objective function was weighted to minimize mean end-diastolic and end-systolic myofiber stress and ignore LV stroke volume. In contrast, the optimization resulted in a nonintuitive optimal pattern (i.e., 3 inclusions longitudinallyx6 inclusions circumferentially) when both myofiber stress and stroke volume were incorporated into the objective function with different weights.

Seismic precursory patterns before a cliff collapse and critical point phenomena

USGS Publications Warehouse

Amitrano, D.; Grasso, J.-R.; Senfaute, G.

2005-01-01

We analyse the statistical pattern of seismicity before a 1-2 103 m3 chalk cliff collapse on the Normandie ocean shore, Western France. We show that a power law acceleration of seismicity rate and energy in both 40 Hz-1.5 kHz and 2 Hz-10kHz frequency range, is defined on 3 orders of magnitude, within 2 hours from the collapse time. Simultaneously, the average size of the seismic events increases toward the time to failure. These in situ results are derived from the only station located within one rupture length distance from the rock fall rupture plane. They mimic the "critical point" like behavior recovered from physical and numerical experiments before brittle failures and tertiary creep failures. Our analysis of this first seismic monitoring data of a cliff collapse suggests that the thermodynamic phase transition models for failure may apply for cliff collapse. Copyright 2005 by the American Geophysical Union.

Lox/Gox related failures during Space Shuttle Main Engine development

NASA Technical Reports Server (NTRS)

Cataldo, C. E.

1981-01-01

Specific rocket engine hardware and test facility system failures are described which were caused by high pressure liquid and/or gaseous oxygen reactions. The failures were encountered during the development and testing of the space shuttle main engine. Failure mechanisms are discussed as well as corrective actions taken to prevent or reduce the potential of future failures.

29 CFR 2200.64 - Failure to appear.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 9 2014-07-01 2014-07-01 false Failure to appear. 2200.64 Section 2200.64 Labor... Hearings § 2200.64 Failure to appear. (a) Attendance at hearing. The failure of a party to appear at a... of good cause, may excuse such failure to appear. In such event, the hearing will be rescheduled as...

29 CFR 2200.64 - Failure to appear.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 9 2012-07-01 2012-07-01 false Failure to appear. 2200.64 Section 2200.64 Labor... Hearings § 2200.64 Failure to appear. (a) Attendance at hearing. The failure of a party to appear at a... of good cause, may excuse such failure to appear. In such event, the hearing will be rescheduled as...

29 CFR 2200.64 - Failure to appear.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 9 2013-07-01 2013-07-01 false Failure to appear. 2200.64 Section 2200.64 Labor... Hearings § 2200.64 Failure to appear. (a) Attendance at hearing. The failure of a party to appear at a... of good cause, may excuse such failure to appear. In such event, the hearing will be rescheduled as...

29 CFR 2200.64 - Failure to appear.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Failure to appear. 2200.64 Section 2200.64 Labor... Hearings § 2200.64 Failure to appear. (a) Attendance at hearing. The failure of a party to appear at a... of good cause, may excuse such failure to appear. In such event, the hearing will be rescheduled as...

29 CFR 2200.64 - Failure to appear.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 9 2011-07-01 2011-07-01 false Failure to appear. 2200.64 Section 2200.64 Labor... Hearings § 2200.64 Failure to appear. (a) Attendance at hearing. The failure of a party to appear at a... of good cause, may excuse such failure to appear. In such event, the hearing will be rescheduled as...

Acute allograft failure in thoracic organ transplantation.

PubMed

Jahania, M S; Mullett, T W; Sanchez, J A; Narayan, P; Lasley, R D; Mentzer, R M

2000-01-01

Thoracic organ transplantation is an effective form of treatment for end-stage heart and lung disease. Despite major advances in the field, transplant patients remain at risk for acute allograft dysfunction, a major cause of early and late mortality. The most common causes of allograft failure include primary graft failure secondary to inadequate heart and lung preservation during cold storage, cellular rejection, and various donor-recipient-related factors. During cold storage and early reperfusion, heart and lung allografts are vulnerable to intracellular calcium overload, acidosis, cell swelling, injury mediated by reactive oxygen species, and the inflammatory response. Brain death itself is associated with a reduction in myocardial contractility, and recipient-related factors such as preexisting pulmonary hypertension can lead to acute right heart failure and the pulmonary reimplantation response. The development of new methods to prevent or treat these various causes of acute graft failure could lead to a marked improvement in short- and long-term survival of patients undergoing thoracic organ transplantation.

The blind leading the blind: Mutual refinement of approximate theories

NASA Technical Reports Server (NTRS)

Kedar, Smadar T.; Bresina, John L.; Dent, C. Lisa

1991-01-01

The mutual refinement theory, a method for refining world models in a reactive system, is described. The method detects failures, explains their causes, and repairs the approximate models which cause the failures. The approach focuses on using one approximate model to refine another.

Reliability of biologic indicators in a mail-return sterilization-monitoring service: a review of 3 years.

PubMed

Andrés, M T; Tejerina, J M; Fierro, J F

1995-12-01

Most mail-return sterilization-monitoring services use spore strips to test sterilizers in dental clinics, but factors such as delay caused by mailing to the laboratory could cause false negatives. The aims of this study were to determine the influence of poststerilization time and temperature on the biologic indicator recovery system and to evaluate sterilization failure and its possible causes in dental clinics subscribing to a mail-return sterilization-monitoring service. Spore strips used in independent tests revealed the poststerilization time and temperature after a 7-day delay to have no significant influence. Sixty-six dental clinics that received quarterly biologic indicators to evaluate the effectiveness of their sterilizers had sterilization failure rates of 28.7% in 1992, 18.1% in 1993, and 9.1% in 1994, a statistically significant decrease in sterilization failure during the 3-year period. The usual causes of failure were operator error in wrapping of instruments, loading, operating temperature, or exposure time.

Failure of Anterior Cruciate Ligament Reconstruction

PubMed Central

Samitier, Gonzalo; Marcano, Alejandro I.; Alentorn-Geli, Eduard; Cugat, Ramon; Farmer, Kevin W; Moser, Michael W

2015-01-01

The present review classifies and describes the multifactorial causes of anterior cruciate ligament (ACL) surgery failure, concentrating on preventing and resolving such situations. The article particularly focuses on those causes that require ACL revision due to recurrent instability, without neglecting those that affect function or produce persistent pain. Although primary ACL reconstruction has satisfactory outcome rates as high as 97%, it is important to identify the causes of failure, because satisfactory outcomes in revision surgery can drop to as much as 76%. It is often possible to identify a primary or secondary cause of ACL surgery failure; even the most meticulous planning can give rise to unexpected findings during the intervention. The adopted protocol should therefore be sufficiently flexible to adapt to the course of surgery. Preoperative patient counseling is essential. The surgeon should limit the patient’s expectations for the outcome by explaining the complexity of this kind of procedure. With adequate preoperative planning, close attention to details and realistic patient expectations, ACL revision surgery may offer beneficial and satisfactory results for the patient. PMID:26550585

The Stressing Effect of Electromigration from the Maxwell Stress and a Preliminary Mean-Time-to-Failure Analysis

NASA Astrophysics Data System (ADS)

Zhou, Peng

2013-06-01

As temperature increases, it is suggested that atoms on lattice sites serve as dynamic defects and cause a much more homogeneous distribution of the Maxwell stress throughout the crystal lattice compared with that caused by static defects. Though this stressing effect mostly leads to Joule heating, it also results in distortion of the crystal lattice, which leads to a decrease in the activation energy for atomic diffusion and causes enhancements in the phase growth rates at both interfaces of diffusion couples. Due to this stressing effect, the decrease in the activation energy is proportional to a square term of the current density J. A mean-time-to-failure analysis is performed for failure caused by excessive growth of intermediate phases, and a mean-time-to-failure (MTTF) equation is found. This equation appears similar to Black's equation but with an extra exponential term arising from the stressing effect of the crystal lattice.

Patterns of failure and survival in patients with nasopharyngeal carcinoma treated with intensity-modulated radiation therapy in Saudi Arabia

PubMed Central

Maklad, Ahmed Marzouk; Bayoumi, Yasser; Senosy Hassan, Mohamed Abdalazez; Elawadi, AbuSaleh A; AlHussain, Hussain; Elyamany, Ashraf; Aldhahri, Saleh F; Al-Qahtani, Khalid Hussain; AlQahtani, Mubarak; Tunio, Mutahir A

2016-01-01

Background We aimed to investigate the patterns of failure (locoregional and distant metastasis), associated factors, and treatment outcomes in nasopharyngeal carcinoma patients treated with intensity-modulated radiation therapy (IMRT) combined with chemotherapy. Patients and methods From April 2006 to December 2011, 68 nasopharyngeal carcinoma patients were treated with IMRT and chemotherapy at our hospital. Median radiation doses delivered to gross tumor volume and positive neck nodes were 66–70 Gy, 63 Gy to clinical target volume, and 50.4–56 Gy to clinically negative neck. The clinical toxicities, patterns of failures, locoregional control, distant metastasis control, disease-free survival, and overall survival were observed. Results The median follow-up time was 52.2 months (range: 11–87 months). Epstein–Barr virus infection was positive in 63.2% of patients. Overall disease failure developed in 21 patients, of whom 85.8% belonged to stage III/IV disease. Among these, there were seven locoregional recurrences, three regional recurrences with distant metastases, and eleven distant metastases. The median interval from the date of diagnosis to failure was 26.5 months (range: 16–50 months). Six of ten (60%) locoregional recurrences were treated with reirradiation ± concurrent chemotherapy. The 5-year locoregional control, distant metastasis control, disease-free survival, and overall survival rates of whole cohort were 81.1%, 74.3%, 60.1%, and 73.4%, respectively. Cox regression analyses revealed that neoadjuvant chemotherapy, age, and Epstein–Barr virus were independent predictors for disease-free survival. Conclusion Neoadjuvant chemotherapy followed by IMRT with or without chemotherapy improves the long-term survival of Saudi patients with nasopharyngeal carcinoma. Distant metastasis was the main pattern of treatment failure. Neoadjuvant chemotherapy, age, and Epstein–Barr virus status before IMRT were important independent prognostic factors. PMID:27822060

Metallurgical failure analysis of MH-1A reactor core hold-down bolts. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hawthorne, J.R.; Watson, H.E.

1976-11-01

The Naval Research Laboratory has performed a failure analysis on two MH-1A reactor core hold-down bolts that broke in service. Adherence to fabrication specifications, post-service properties and possible causes of bolt failure were investigated. The bolt material was verified as 17-4PH precipitation hardening stainless steel. Measured bolt dimensions also were in accordance with fabrication drawing specifications. Bolt failure occurred in the region of a locking pin hole which reduced the bolt net section by 47 percent. The failure analysis indicates that the probable cause of failure was net section overloading resulting from a lateral bending force on the bolt. Themore » analysis indicates that net section overloading could also have resulted from combined tensile stresses (bolt preloading plus differential thermal expansion). Recommendations are made for improved bolting.« less

Constructing Failure: Leonard Hayflick, Biomedicine, and the Problems with Tissue Culture.

PubMed

Park, Hyung Wook

2016-07-01

By examining the use of tissue culture in post-war American biomedicine, this paper investigates how scientists experience and manage failure. I study how Leonard Hayflick forged his new definition of failure and ways of managing it by refuting Alexis Carrel's definition of failure alongside his theory of the immortality of cultured cells. Unlike Carrel, Hayflick claimed that every vertebrate somatic cell should eventually die, unless it transformed into a tumour cell. This claim defined cell death, which had been a problem leading to a laboratory failure, as a normal phenomenon. On the other hand, permanent life, which had been considered a normal cellular characteristic, became a major factor causing scientific failure, since it implied malignant transformation that scientists hoped to control. Hayflick then asserted that his cell strains and method would partly enable scientists to manage this factor-especially that occurred through viral infection-alongside other causes of failure in routine tasks, including bacterial contamination. I argue that the growing biomedical enterprise fostered this work of Hayflick's, which had repercussions in both his career and the uses of cells in diverse investigations. His redefinition of failure in the age of biomedicine resulted in the broad dissemination of his cells, medium, and method as well as his long struggle with the National Institutes of Health (NIH), which caused his temporarily failed career.

De novo noncutaneous malignancies after kidney transplantation are associated with an increased risk of graft failure: results from a time-dependent analysis on 672 patients.

PubMed

Cena, Tiziana; Musetti, Claudio; Quaglia, Marco; Magnani, Corrado; Stratta, Piero; Bagnardi, Vincenzo; Cantaluppi, Vincenzo

2016-10-01

The aim of this study was to evaluate the association between cancer occurrence and risk of graft failure in kidney transplant recipients. From November 1998 to November 2013, 672 adult patients received their first kidney transplant from a deceased donor and had a minimum follow-up of 6 months. During a median follow-up of 4.7 years (3523 patient-years), 47 patients developed a nonmelanoma skin cancer (NMSC) and 40 a noncutaneous malignancy (NCM). A total of 59 graft failures were observed. The failure rate was 6 per 100 patient-year (pt-yr) after NCM versus 1.5 per 100 pt-yr in patients without NCM. In a time-dependent multivariable model, the occurrence of NCM appeared to be associated with failure (HR = 3.27; 95% CI = 1.44-7.44). The effect of NCM on the cause-specific graft failure was different (P = 0.002) when considering events due to chronic rejection (HR = 0.55) versus other causes (HR = 15.59). The reduction of the immunosuppression after NCM was not associated with a greater risk of graft failure. In conclusion, our data suggest that post-transplant NCM may be a strong risk factor for graft failure, particularly for causes other than chronic rejection. © 2016 Steunstichting ESOT.

Obesity Paradox: Comparison of Heart Failure Patients With and Without Comorbid Diabetes.

PubMed

Lee, Kyoung Suk; Moser, Debra K; Lennie, Terry A; Pelter, Michele M; Nesbitt, Thomas; Southard, Jeffrey A; Dracup, Kathleen

2017-03-01

Diabetes is a common comorbid condition in patients with heart failure and is strongly associated with poor outcomes. Patients with heart failure who have diabetes are more likely to be obese than are those without diabetes. Obesity is positively associated with survival in patients with heart failure, but how comorbid diabetes influences the relationship between obesity and favorable prognosis is unclear. To explore whether the relationship between body mass index and survival differs between patients with heart failure who do or do not have diabetes. The sample consisted of 560 ambulatory patients with heart failure (mean age, 66 years; mean body mass index, 32; diabetes, 41%). The association between body mass index and all-cause mortality was examined by using multivariate Cox proportional hazards regression after adjustments for covariates. In patients without diabetes, higher body mass index was associated with a lower risk for all-cause mortality after adjustments for covariates (hazard ratio, 0.952; 95% CI, 0.909-0.998). In patients with diabetes, body mass index was not predictive of all-cause death after adjustments for covariates. Obesity was a survival benefit in heart failure patients without comorbid diabetes but not in those with comorbid diabetes. The mechanisms underlying the difference in the relationship between obesity and survival due to the presence of diabetes in patients with heart failure need to be elucidated. ©2017 American Association of Critical-Care Nurses.

Plasma bacterial and mitochondrial DNA distinguish bacterial sepsis from sterile systemic inflammatory response syndrome and quantify inflammatory tissue injury in nonhuman primates.

PubMed

Sursal, Tolga; Stearns-Kurosawa, Deborah J; Itagaki, Kiyoshi; Oh, Sun-Young; Sun, Shiqin; Kurosawa, Shinichiro; Hauser, Carl J

2013-01-01

Systemic inflammatory response syndrome (SIRS) is a fundamental host response common to bacterial infection and sterile tissue injury. Systemic inflammatory response syndrome can cause organ dysfunction and death, but its mechanisms are incompletely understood. Moreover, SIRS can progress to organ failure or death despite being sterile or after control of the inciting infection. Biomarkers discriminating between sepsis, sterile SIRS, and postinfective SIRS would therefore help direct care. Circulating mitochondrial DNA (mtDNA) is a damage-associated molecular pattern reflecting cellular injury. Circulating bacterial 16S DNA (bDNA) is a pathogen-associated pattern (PAMP) reflecting ongoing infection. We developed quantitative polymerase chain reaction assays to quantify these markers, and predicting their plasma levels might help distinguish sterile injury from infection. To study these events in primates, we assayed banked serum from Papio baboons that had undergone a brief challenge of intravenous Bacillus anthracis delta Sterne (modified to remove toxins) followed by antibiotics (anthrax) that causes organ failure and death. To investigate the progression of sepsis to "severe" sepsis and death, we studied animals where anthrax was pretreated with drotrecogin alfa (activated protein C), which attenuates sepsis in baboons. We also contrasted lethal anthrax bacteremia against nonlethal E. coli bacteremia and against sterile tissue injury from Shiga-like toxin 1. Bacterial DNA and mtDNA levels in timed samples were correlated with blood culture results and assays of organ function. Sterile injury by Shiga-like toxin 1 increased mtDNA, but bDNA was undetectable: consistent with the absence of infection. The bacterial challenges caused parallel early bDNA and mtDNA increases, but bDNA detected pathogens even after bacteria were undetectable by culture. Sublethal E. coli challenge only caused transient rises in mtDNA consistent with a self-limited injury. In lethal anthrax challenge (n = 4), bDNA increased transiently, but mtDNA levels remained elevated until death, consistent with persistent septic tissue damage after bacterial clearance. Critically, activated protein C pretreatment (n = 4) allowed mtDNA levels to decay after bacterial clearance with sparing of organ function and survival. In summary, host tissue injury correlates with mtDNA whether infective or sterile. Mitochondrial DNA and bDNA polymerase chain reactions can quantify tissue injury incurred by septic or sterile mechanisms and suggest the source of SIRS of unknown origin.

Plasma Bacterial and Mitochondrial DNA Distinguish Bacterial Sepsis from Sterile SIRS and Quantify Inflammatory Tissue Injury in Nonhuman Primates

PubMed Central

Sursal, Tolga; Stearns-Kurosawa, Deborah J; Itagaki, Kiyoshi; Oh, Sun-Young; Sun, Shiqin; Kurosawa, Shinichiro; Hauser, Carl J

2012-01-01

Systemic inflammatory response syndrome (SIRS) is a fundamental host response common to bacterial infection and sterile tissue injury. SIRS can cause organ dysfunction and death but its mechanisms are incompletely understood. Moreover, SIRS can progress to organ failure or death despite being sterile or after control of the inciting infection. Biomarkers discriminating between sepsis, sterile SIRS and post-infective SIRS would therefore help direct care. Circulating mitochondrial DNA (mtDNA) is a damage-associated molecular pattern (DAMP) reflecting cellular injury. Circulating bacterial 16S-DNA (bDNA) is a pathogen-associated pattern (PAMP) reflecting ongoing infection. We developed qPCR assays to quantify these markers and predicted their plasma levels might help distinguish sterile injury from infection. To study these events in primates we assayed banked serum from papio baboons that had undergone a brief challenge of intravenous Bacillus anthracis deltaSterne (modified to remove toxins) followed by antibiotics (anthrax) that causes organ failure and death. To investigate the progression of sepsis to “severe” sepsis and death we studied animals where anthrax was pretreated with drotrecogin alfa (aPC), which attenuates sepsis in baboons. We also contrasted lethal anthrax bacteremia against non-lethal E.coli bacteremia and against sterile tissue injury from Shiga-like toxin-1 (Stx1). bDNA and mtDNA levels in timed samples were correlated with blood culture results and assays of organ function. Sterile injury by Stx1 increased mtDNA but bDNA was undetectable: consistent with the absence of infection. The bacterial challenges caused parallel early bDNA and mtDNA increases, but bDNA detected pathogens even after bacteria were undetectable by culture. Sub-lethal E.coli challenge only caused transient rises in mtDNA consistent with a self-limited injury. In lethal anthrax challenge (n=4) bDNA increased transiently but mtDNA levels remained elevated until death, consistent with persistent septic tissue damage after bacterial clearance. Critically, aPC pre-treatment (n=4) allowed mtDNA levels to decay after bacterial clearance with sparing of organ function and survival. In summary, host tissue injury correlates with mtDNA whether infective or sterile. mtDNA and bDNA PCRs can quantify tissue injury incurred by septic or sterile mechanisms and suggest the source of SIRS of unknown origin. PMID:23247122

Exploring the Waveform Characteristics of Tidal Breathing Carbon Dioxide, Measured Using the N-Tidal C Device in Different Breathing Conditions (The General Breathing Record Study): Protocol for an Observational, Longitudinal Study

PubMed Central

Rupani, Hitasha; Kalra, Paul R; Adeniji, Kayode; Quint, Matthew; De Vos, Ruth; Begum, Selina; Mottershaw, Mark; Fogg, Carole; Jones, Thomas L; Lanning, Eleanor; Bassett, Paul; Chauhan, Anoop J

2018-01-01

Background In an increasingly comorbid population, there are significant challenges to diagnosing the cause of breathlessness, and once diagnosed, considerable difficulty in detecting deterioration early enough to provide effective intervention. The burden of the breathless patient on the health care economy is substantial, with asthma, chronic heart failure, and pneumonia affecting over 6 million people in the United Kingdom alone. Furthermore, these patients often have more than one contributory factor to their breathlessness symptoms, with conditions such as dysfunctional breathing pattern disorders—an under-recognized component. Current methods of diagnosing and monitoring breathless conditions can be extensive and difficult to perform. As a consequence, home monitoring is poorly complied with. In contrast, capnography (the measurement of tidal breath carbon dioxide) is performed during normal breathing. There is a need for a simple, easy-to-use, personal device that can aid in the diagnosis and monitoring of respiratory and cardiac causes of breathlessness. Objective The aim of this study was to explore the use of a new, handheld capnometer (called the N-Tidal C) in different conditions that cause breathlessness. We will study whether the tidal breath carbon dioxide (TBCO2) waveform, as measured by the N-Tidal C, has different characteristics in a range of respiratory and cardiac conditions. Methods We will perform a longitudinal, observational study of the TBCO2 waveform (capnogram) as measured by the N-Tidal C capnometer. Participants with a confirmed diagnosis of asthma, breathing pattern disorders, chronic heart failure, motor neurone disease, pneumonia, as well as volunteers with no history of lung disease will be asked to provide twice daily, 75-second TBCO2 collection via the N-Tidal C device for 6 months duration. The collated capnograms will be correlated with the underlying diagnosis and disease state (stable or exacerbation) to determine if there are different TBCO2 characteristics that can distinguish different respiratory and cardiac causes of breathlessness. Results This study’s recruitment is ongoing. It is anticipated that the results will be available in late 2018. Conclusions The General Breathing Record Study will provide an evaluation of the use of capnography as a diagnostic and home-monitoring tool for various diseases. Registered Report Identifier RR1-10.2196/9767 PMID:29798833

Effect of hierarchy legitimacy on low status group members' attributions for ingroup and outgroup failures.

PubMed

Beatson, Ruth M; Halloran, Michael J

2015-04-01

Previous research has shown that people have a tendency to explain successes and failures in ways that favor their ingroups relative to outgroups. However, there has been a dearth of research examining whether social-contextual factors such as group status and hierarchy legitimacy moderate such intergroup attributions. Participants in this study were assigned to a low status group, and perceived hierarchy legitimacy was then experimentally manipulated; the extent to which ingroup versus outgroup failures were attributed to several causes was measured. When low status was considered illegitimate, ingroup failure was attributed to external causes (task difficulty, bad luck) more so than outgroup failure. Implications and directions for future research examining consequences and mediating processes are discussed.

Oblique impacts into low impedance layers

NASA Astrophysics Data System (ADS)

Stickle, A. M.; Schultz, P. H.

2009-12-01

Planetary impacts occur indiscriminately, in all locations and materials. Varied geologic settings can have significant effects on the impact process, including the coupling between the projectile and target, the final damage patterns and modes of deformation that occur. For example, marine impact craters are not identical to impacts directly into bedrock or into sedimentary materials, though many of the same fundamental processes occur. It is therefore important, especially when considering terrestrial impacts, to understand how a low impedance sedimentary layer over bedrock affects the deformation process during and after a hypervelocity impact. As a first step, detailed comparisons between impacts and hydrocode models were performed. Experiments performed at the NASA Ames Vertical Gun Range of oblique impacts into polymethylmethacrylate (PMMA) targets with low impedance layers were performed and compared to experiments of targets without low impedance layers, as well as to hydrocode models under identical conditions. Impact velocities ranged from 5 km/s to 5.6 km/s, with trajectories from 30 degrees to 90 degrees above the horizontal. High-speed imaging provided documentation of the sequence and location of failure due to impact, which was compared to theoretical models. Plasticine and ice were used to construct the low impedance layers. The combination of experiments and models reveals the modes of failure due to a hypervelocity impact. How such failure is manifested at large scales can present a challenge for hydrocodes. CTH models tend to overestimate the amount of damage occurring within the targets and have difficulties perfectly reproducing morphologies; nevertheless, they provide significant and useful information about the failure modes and style within the material. CTH models corresponding to the experiments allow interpretation of the underlying processes involved as well as provide a benchmark for the experimental analysis. The transparency of PMMA allows a clear view of failure patterns within the target, providing a 3D picture of the final damage, as well as damage formation and propagation. Secondly, PMMA has mechanical properties similar to those of brittle rocks in the upper crust, making it an appropriate material for comparison to geologic materials. An impact into a PMMA target with a one-projectile-diameter thick plasticine layer causes damage distinct from an impact into a PMMA target without a low impedance layer. The extent of the final damage is much less in the target with the low impedance layer and begins to form at later times, there is little to no crater visible on the surface, and the formation and propagation of the damage is completely different, creating distinct subsurface damage patterns. Three-dimensional CTH hydrocode models show that the pressure history of material around and underneath the impact point is also different when a low impedance layer is present, leading to the variations in damage forming within the targets.

Active Diagnosis of Navy Machinery Rev 2.0

DTIC Science & Technology

2016-10-01

electrical distribution and potable water supply systems. Because of these dependencies, ship auxiliary system failures can cause combat load failure...buildup generally causes a pipe to disconnect from a junction, causing water to leak . This limits the faults that are testable, since many of the faults...pipes, junctions, pumps, flow meters, thermal loads, check valve, and water tank. Each agent is responsible for maintaining its constraints locally

Biallelic Mutations in NBAS Cause Recurrent Acute Liver Failure with Onset in Infancy.

PubMed

Haack, Tobias B; Staufner, Christian; Köpke, Marlies G; Straub, Beate K; Kölker, Stefan; Thiel, Christian; Freisinger, Peter; Baric, Ivo; McKiernan, Patrick J; Dikow, Nicola; Harting, Inga; Beisse, Flemming; Burgard, Peter; Kotzaeridou, Urania; Kühr, Joachim; Himbert, Urban; Taylor, Robert W; Distelmaier, Felix; Vockley, Jerry; Ghaloul-Gonzalez, Lina; Zschocke, Johannes; Kremer, Laura S; Graf, Elisabeth; Schwarzmayr, Thomas; Bader, Daniel M; Gagneur, Julien; Wieland, Thomas; Terrile, Caterina; Strom, Tim M; Meitinger, Thomas; Hoffmann, Georg F; Prokisch, Holger

2015-07-02

Acute liver failure (ALF) in infancy and childhood is a life-threatening emergency. Few conditions are known to cause recurrent acute liver failure (RALF), and in about 50% of cases, the underlying molecular cause remains unresolved. Exome sequencing in five unrelated individuals with fever-dependent RALF revealed biallelic mutations in NBAS. Subsequent Sanger sequencing of NBAS in 15 additional unrelated individuals with RALF or ALF identified compound heterozygous mutations in an additional six individuals from five families. Immunoblot analysis of mutant fibroblasts showed reduced protein levels of NBAS and its proposed interaction partner p31, both involved in retrograde transport between endoplasmic reticulum and Golgi. We recommend NBAS analysis in individuals with acute infantile liver failure, especially if triggered by fever. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Diseases causing end-stage renal failure in New South Wales.

PubMed Central

Stewart, J H; McCarthy, S W; Storey, B G; Roberts, B A; Gallery, E; Mahony, J F

1975-01-01

The nature of the original renal disease was determined in 403 consecutive cases of end-stage renal failure, in 317 of which the clinical diagnosis was corroborated by histological examination of the kidney. Five diseases accounted for 20 or more cases--glomerulonephritis (31% of the total), analgesic nephropathy (29%), primary vesicoureteral reflux (8%), essential hypertension (6%), and polycystic kidneys (5%). In only four cases did renal failure result from chronic pyelonephritis without a demonstrable primary cause. Greater use of micturating cystography and cystoscopy and routine urine testing for salicylate are advocated for earlier diagnosis of the major causes of "pyelonephritis". The incidence of end-stage renal failure in people aged 15-55 in New South Wales was estimated to be at least 34 new cases per million of total population each year. PMID:1090338

Congenital Proprotein Convertase 1/3 Deficiency Causes Malabsorptive Diarrhea and other Endocrinopathies in a Pediatric Cohort

PubMed Central

Martín, Martín G.; Lindberg, Iris; Solorzano-Vargas, R. Sergio; Wang, Jiafang; Avitzur, Yaron; Bandsma, Robert; Sokollik, Christiane; Lawrence, Sarah; Pickett, Lindsay A.; Chen, Zijun; Egritas, Odul; Dalgic, Buket; Albornoz, Valeria; de Ridder, Lissy; Hulst, Jessie; Gok, Faysal; Aydoğan, Ayşen; Al-Hussaini, Abdulrahman; Gok, Deniz Engin; Yourshaw, Michael; Wu, S. Vincent; Cortina, Galen; Stanford, Sara; Georgia, Senta

2013-01-01

Background & Aims Proprotein convertase 1/3 (PC1/3) deficiency, an autosomal recessive disorder caused by rare mutations in the PCSK1 gene, has been associated with obesity, severe malabsorptive diarrhea, and certain endocrine abnormalities. Common variants in PCSK1 have also been associated with obesity in heterozygotes in several population studies. PC1/3 is an endoprotease that processes many prohormones expressed in endocrine and neuronal cells. We investigated clinical and molecular features of PC1/3 deficiency. Methods We studied the clinical features of 13 children with PC1/3 deficiency and performed sequence analysis of PCSK1. We measured enzymatic activity of recombinant PC1/3 proteins. Results We identified a pattern of endocrinopathies that develop in an age-dependent manner. Eight of the mutations had severe biochemical consequences in vitro. Neonates had severe malabsorptive diarrhea and failure to thrive, required prolonged parenteral nutrition support, and had high mortality. Additional endocrine abnormalities developed as the disease progressed, including diabetes insipidus, growth hormone deficiency, primary hypogonadism, adrenal insufficiency, and hypothyroidism. We identified growth hormone deficiency, central diabetes insipidus, and male hypogonadism as new features of PCSK1 insufficiency. Interestingly, despite early growth abnormalities, moderate obesity, associated with severe polyphagia, generally appears. Conclusion In a study of 13 children with PC1/3 deficiency caused by disruption of PCSK1, failure of enteroendocrine cells to produce functional hormones resulted in generalized malabsorption. These findings indicate that PC1/3 is involved in processing of one or more enteric hormones that are required for nutrient absorption. PMID:23562752

Impact of Diverse Hydrologic Pathways, 3D Failure Geometries, and Unsaturated Soil Suctions on Shallow Landsliding

NASA Astrophysics Data System (ADS)

Reid, M. E.; Iverson, R. M.; Brien, D. L.; Iverson, N. R.; Lahusen, R. G.; Logan, M.

2016-12-01

Shallow landslides and ensuing debris flows can be triggered by diverse hydrologic phenomena such as groundwater inflow, prolonged moderate-intensity precipitation, or bursts of high-intensity precipitation. However, hazard assessments typically rely on simplistic hydrologic models that disregard this diversity. We used the USGS debris-flow flume to conduct controlled, field-scale slope failure experiments designed to investigate the effects of diverse hydrologic pathways, as well as the effects of 3D landslide geometries and suction stresses in unsaturated soil. Using overhead sprinklers or groundwater injectors on the flume bed, we induced failures in 6 m3 (0.65-m thick and 2-m wide) prisms of loamy sand on a 31º slope. We used 50 sensors to monitor soil deformation, variably saturated pore pressures, and moisture changes. We also determined shear strength, hydraulic conductivity, and unsaturated moisture retention characteristics from ancillary tests. The three hydrologic scenarios noted above led to different behaviors. Groundwater injection and prolonged infiltration created differing soil moisture patterns. Intense sprinkling bursts caused rapid failure without development of widespread positive pore pressures. We simulated these observed differences numerically by coupling 2D variably saturated groundwater flow modeling and 3D limit-equilibrium analysis. We also simulated the time evolution of changes in factors of safety, and quantified the mechanical effects of 3D geometry and unsaturated soil suction on stability. When much of the soil became relatively wet, effects of 3D geometry and soil suction produced slight increases ( 10-20%) in factors of safety. Suction effects were more pronounced with drier soils. Our results indicate that simplistic models cannot consistently predict the timing of slope failure, and that high frequency monitoring (with sampling periods < 60 s) is needed to measure and interpret the effects of rapid hydrologic triggers.

Rock falls from Glacier Point above Camp Curry, Yosemite National Park, California

USGS Publications Warehouse

Wieczorek, Gerald F.; Snyder, James B.

1999-01-01

A series of rock falls from the north face of Glacier Point above Camp Curry, Yosemite National Park, California, have caused reexamination of the rock-fall hazard because beginning in June, 1999 a system of cracks propagated through a nearby rock mass outlining a future potential rock fall. If the estimated volume of the potential rock fall fails as a single piece, there could be a risk from rock-fall impact and airborne rock debris to cabins in Camp Curry. The role of joint plane orientation and groundwater pressure in the fractured rock mass are discussed in light of the pattern of developing cracks and potential modes of failure.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shade, Ashley

Local diversity (within-sample or alpha diversity) is often implicated as a cause of success or failure of a microbial community. However, the relationships between diversity and emergent properties of a community, such as its stability, productivity or invasibility, are much more nuanced. In this paper, I argue that diversity without context provides limited insights into the mechanisms underpinning community patterns. I provide examples from traditional and microbial ecology to discuss common complications and assumptions about within-sample diversity that may prevent us from digging deeper into the more specific mechanisms underpinning community outcomes. I suggest that measurement of diversity should servemore » as a starting point for further inquiry of ecological mechanisms rather than an 'answer' to community outcomes.« less

Underlying Cause(s) of Letter Perseveration Errors

ERIC Educational Resources Information Center

Fischer-Baum, Simon; Rapp, Brenda

2012-01-01

Perseverations, the inappropriate intrusion of elements from a previous response into a current response, are commonly observed in individuals with acquired deficits. This study specifically investigates the contribution of failure-to activate and failure-to-inhibit deficit(s) in the generation of letter perseveration errors in acquired…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Devpura, S; Li, H; Liu, C

Purpose: To correlate dose distributions computed using six algorithms for recurrent early stage non-small cell lung cancer (NSCLC) patients treated with stereotactic body radiotherapy (SBRT), with outcome (local failure). Methods: Of 270 NSCLC patients treated with 12Gyx4, 20 were found to have local recurrence prior to the 2-year time point. These patients were originally planned with 1-D pencil beam (1-D PB) algorithm. 4D imaging was performed to manage tumor motion. Regions of local failures were determined from follow-up PET-CT scans. Follow-up CT images were rigidly fused to the planning CT (pCT), and recurrent tumor volumes (Vrecur) were mapped to themore » pCT. Dose was recomputed, retrospectively, using five algorithms: 3-D PB, collapsed cone convolution (CCC), anisotropic analytical algorithm (AAA), AcurosXB, and Monte Carlo (MC). Tumor control probability (TCP) was computed using the Marsden model (1,2). Patterns of failure were classified as central, in-field, marginal, and distant for Vrecur ≥95% of prescribed dose, 95–80%, 80–20%, and ≤20%, respectively (3). Results: Average PTV D95 (dose covering 95% of the PTV) for 3-D PB, CCC, AAA, AcurosXB, and MC relative to 1-D PB were 95.3±2.1%, 84.1±7.5%, 84.9±5.7%, 86.3±6.0%, and 85.1±7.0%, respectively. TCP values for 1-D PB, 3-D PB, CCC, AAA, AcurosXB, and MC were 98.5±1.2%, 95.7±3.0, 79.6±16.1%, 79.7±16.5%, 81.1±17.5%, and 78.1±20%, respectively. Patterns of local failures were similar for 1-D and 3D PB plans, which predicted that the majority of failures occur in centraldistal regions, with only ∼15% occurring distantly. However, with convolution/superposition and MC type algorithms, the majority of failures (65%) were predicted to be distant, consistent with the literature. Conclusion: Based on MC and convolution/superposition type algorithms, average PTV D95 and TCP were ∼15% lower than the planned 1-D PB dose calculation. Patterns of failure results suggest that MC and convolution/superposition type algorithms predict different outcomes for patterns of failure relative to PB algorithms. Work supported in part by Varian Medical Systems, Palo Alto, CA.« less

Cardiac Resynchronization Therapy (CRT)

MedlinePlus

... with other treatments to achieve the best results. Heart Failure Questions to Ask Your Doctor Use these questions ... and procedures related to heart disease and stroke. Heart Failure • Home • About Heart Failure • Causes and Risks for ...

Heart Failure

MedlinePlus

... cause heart failure, such as coronary artery disease, high blood pressure, diabetes or obesity. Symptoms Heart failure can be ongoing ( ... include: Not smoking Controlling certain conditions, such as high blood pressure and diabetes Staying physically active Eating healthy foods Maintaining a ...

Drugs That May Cause or Exacerbate Heart Failure: A Scientific Statement From the American Heart Association.

PubMed

Page, Robert L; O'Bryant, Cindy L; Cheng, Davy; Dow, Tristan J; Ky, Bonnie; Stein, C Michael; Spencer, Anne P; Trupp, Robin J; Lindenfeld, JoAnn

2016-08-09

Heart failure is a common, costly, and debilitating syndrome that is associated with a highly complex drug regimen, a large number of comorbidities, and a large and often disparate number of healthcare providers. All of these factors conspire to increase the risk of heart failure exacerbation by direct myocardial toxicity, drug-drug interactions, or both. This scientific statement is designed to serve as a comprehensive and accessible source of drugs that may cause or exacerbate heart failure to assist healthcare providers in improving the quality of care for these patients. © 2016 American Heart Association, Inc.

Validation Study of Unnotched Charpy and Taylor-Anvil Impact Experiments using Kayenta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamojjala, Krishna; Lacy, Jeffrey; Chu, Henry S.

2015-03-01

Validation of a single computational model with multiple available strain-to-failure fracture theories is presented through experimental tests and numerical simulations of the standardized unnotched Charpy and Taylor-anvil impact tests, both run using the same material model (Kayenta). Unnotched Charpy tests are performed on rolled homogeneous armor steel. The fracture patterns using Kayenta’s various failure options that include aleatory uncertainty and scale effects are compared against the experiments. Other quantities of interest include the average value of the absorbed energy and bend angle of the specimen. Taylor-anvil impact tests are performed on Ti6Al4V titanium alloy. The impact speeds of the specimenmore » are 321 m/s and 393 m/s. The goal of the numerical work is to reproduce the damage patterns observed in the laboratory. For the numerical study, the Johnson-Cook failure model is used as the ductile fracture criterion, and aleatory uncertainty is applied to rate-dependence parameters to explore its effect on the fracture patterns.« less

East coast fever caused by Theileria parva is characterized by macrophage activation associated with vasculitis and respiratory failure

USDA-ARS?s Scientific Manuscript database

Respiratory failure and death in East Coast Fever (ECF), a clinical syndrome of African cattle caused by the apicomplexan parasite Theileria parva, has historically been attributed to pulmonary infiltration by infected lymphocytes. However, immunohistochemical staining of tissue from T. parva infect...

Investigation of premature strip seal joint failures and recommendations for assuring proper strip seal joint installation: Bridge 5/104W.

DOT National Transportation Integrated Search

2015-08-01

This document summarizes an investigation that was performed to identify the cause(s) of premature failures of : strip seal expansion joints that were installed on WSDOT Bridge No. 5/104W. The document also includes recommendations : for assuring pro...

42 CFR 417.810 - Final settlement.

Code of Federal Regulations, 2011 CFR

2011-10-01

... common ownership or control; (ii) The HCPP's methods of apportioning costs among its Medicare enrollees... extension of time to submit a cost report for good cause shown. (4) Failure to report required financial... good cause shown, CMS may— (i) Regard the failure to report this information as evidence of likely...

76 FR 70768 - Common-Cause Failure Analysis in Event and Condition Assessment: Guidance and Research, Draft...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-15

... NUCLEAR REGULATORY COMMISSION [NRC-2011-0254] Common-Cause Failure Analysis in Event and Condition Assessment: Guidance and Research, Draft Report for Comment; Correction AGENCY: Nuclear Regulatory Commission. ACTION: Draft NUREG; request for comment; correction. SUMMARY: This document corrects a notice appearing...

Activation of Background Knowledge for Inference Making: Effects on Reading Comprehension

ERIC Educational Resources Information Center

Elbro, Carsten; Buch-Iversen, Ida

2013-01-01

Failure to "activate" relevant, existing background knowledge may be a cause of poor reading comprehension. This failure may cause particular problems with inferences that depend heavily on prior knowledge. Conversely, teaching how to use background knowledge in the context of gap-filling inferences could improve reading comprehension in…

Causes of catastrophic failure in complex systems

NASA Astrophysics Data System (ADS)

Thomas, David A.

2010-08-01

Root causes of mission critical failures and major cost and schedule overruns in complex systems and programs are studied through the post-mortem analyses compiled for several examples, including the Hubble Space Telescope, the Challenger and Columbia Shuttle accidents, and the Three Mile Island nuclear power plant accident. The roles of organizational complexity, cognitive biases in decision making, the display of quantitative data, and cost and schedule pressure are all considered. Recommendations for mitigating the risk of similar failures in future programs are also provided.

Mathematics, Questions, and "Schools Without Failure"

ERIC Educational Resources Information Center

Perl, Teri

1974-01-01

Most questions in the mathematics classroom deal with memorization and learning, and have one correct answer. Suggestions for using three other types of questions identified by Glasser (SCHOOLS WITHOUT FAILURE) are provided. Activities discussed include tangrams, attribute blocks, pattern recognition, and games. (SD)

Failure-Modes-And-Effects Analysis Of Software Logic

NASA Technical Reports Server (NTRS)

Garcia, Danny; Hartline, Thomas; Minor, Terry; Statum, David; Vice, David

1996-01-01

Rigorous analysis applied early in design effort. Method of identifying potential inadequacies and modes and effects of failures caused by inadequacies (failure-modes-and-effects analysis or "FMEA" for short) devised for application to software logic.

Equipment failures and their contribution to industrial incidents and accidents in the manufacturing industry.

PubMed

Bourassa, Dominic; Gauthier, François; Abdul-Nour, Georges

2016-01-01

Accidental events in manufacturing industries can be caused by many factors, including work methods, lack of training, equipment design, maintenance and reliability. This study is aimed at determining the contribution of failures of commonly used industrial equipment, such as machines, tools and material handling equipment, to the chain of causality of industrial accidents and incidents. Based on a case study which aimed at the analysis of an existing pulp and paper company's accident database, this paper examines the number, type and gravity of the failures involved in these events and their causes. Results from this study show that equipment failures had a major effect on the number and severity of accidents accounted for in the database: 272 out of 773 accidental events were related to equipment failure, where 13 of them had direct human consequences. Failures that contributed directly or indirectly to these events are analyzed.

Investigation into Cause of High Temperature Failure of Boiler Superheater Tube

NASA Astrophysics Data System (ADS)

Ghosh, D.; Ray, S.; Roy, H.; Shukla, A. K.

2015-04-01

The failure of the boiler tubes occur due to various reasons like creep, fatigue, corrosion and erosion. This paper highlights a case study of typical premature failure of a final superheater tube of 210 MW thermal power plant boiler. Visual examination, dimensional measurement, chemical analysis, oxide scale thickness measurement, microstructural examination are conducted as part of the investigations. Apart from these investigations, sulfur print, Energy Dispersive spectroscopy (EDS) and X ray diffraction analysis (XRD) are also conducted to ascertain the probable cause of failure of final super heater tube. Finally it has been concluded that the premature failure of the super heater tube can be attributed to the combination of localized high tube metal temperature and loss of metal from the outer surface due to high temperature corrosion. The corrective actions have also been suggested to avoid this type of failure in near future.

Histopathological characterization of corrosion product associated adverse local tissue reaction in hip implants: a study of 285 cases.

PubMed

Ricciardi, Benjamin F; Nocon, Allina A; Jerabek, Seth A; Wilner, Gabrielle; Kaplowitz, Elianna; Goldring, Steven R; Purdue, P Edward; Perino, Giorgio

2016-01-01

Adverse local tissue reaction (ALTR), characterized by a heterogeneous cellular inflammatory infiltrate and the presence of corrosion products in the periprosthetic soft tissues, has been recognized as a mechanism of failure in total hip replacement (THA). Different histological subtypes may have unique needs for longitudinal clinical follow-up and complication rates after revision arthroplasty. The purpose of this study was to describe the histological patterns observed in the periprosthetic tissue of failed THA in three different implant classes due to ALTR and their association with clinical features of implant failure. Consecutive patients presenting with ALTR from three major hip implant classes (N = 285 cases) were identified from our prospective Osteolysis Tissue Database and Repository. Clinical characteristics including age, sex, BMI, length of implantation, and serum metal ion levels were recorded. Retrieved synovial tissue morphology was graded using light microscopy. Clinical characteristics and features of synovial tissue analysis were compared between the three implant classes. Histological patterns of ALTR identified from our observations and the literature were used to classify each case. The association between implant class and histological patterns was compared. Our histological analysis demonstrates that ALTR encompasses three main histological patterns: 1) macrophage predominant, 2) mixed lymphocytic and macrophagic with or without features of associated with hypersensitivity/allergy or response to particle toxicity (eosinophils/mast cells and/or lymphocytic germinal centers), and 3) predominant sarcoid-like granulomas. Implant classification was associated with histological pattern of failure, and the macrophagic predominant pattern was more common in implants with metal-on-metal bearing surfaces (MoM HRA and MoM LHTHA groups). Duration of implantation and composition of periprosthetic cellular infiltrates was significantly different amongst the three implant types examined suggesting that histopathological features of ALTR may explain the variability of clinical implant performance in these cases. ALTR encompasses a diverse range of histological patterns, which are reflective of both the implant configuration independent of manufacturer and clinical features such as duration of implantation. The macrophagic predominant pattern and its mechanism of implant failure represent an important subgroup of ALTR which could become more prominent with increased length of implantation.

Analytical Study of different types Of network failure detection and possible remedies

NASA Astrophysics Data System (ADS)

Saxena, Shikha; Chandra, Somnath

2012-07-01

Faults in a network have various causes,such as the failure of one or more routers, fiber-cuts, failure of physical elements at the optical layer, or extraneous causes like power outages. These faults are usually detected as failures of a set of dependent logical entities and the links affected by the failed components. A reliable control plane plays a crucial role in creating high-level services in the next-generation transport network based on the Generalized Multiprotocol Label Switching (GMPLS) or Automatically Switched Optical Networks (ASON) model. In this paper, approaches to control-plane survivability, based on protection and restoration mechanisms, are examined. Procedures for the control plane state recovery are also discussed, including link and node failure recovery and the concepts of monitoring paths (MPs) and monitoring cycles (MCs) for unique localization of shared risk linked group (SRLG) failures in all-optical networks. An SRLG failure is a failure of multiple links due to a failure of a common resource. MCs (MPs) start and end at same (distinct) monitoring location(s). They are constructed such that any SRLG failure results in the failure of a unique combination of paths and cycles. We derive necessary and sufficient conditions on the set of MCs and MPs needed for localizing an SRLG failure in an arbitrary graph. Procedure of Protection and Restoration of the SRLG failure by backup re-provisioning algorithm have also been discussed.

Failures in Hybrid Microcircuits During Environmental Testing. History Cases

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2008-01-01

This purpose of this viewgraph presentation is to discuss failures in hermetic hybrids observed at the GSFC PA Lab during environmental stress testing. The cases discussed are: Case I. Substrate metallization failures during Thermal cycling (TC). Case II. Flex lid-induced failure. Case Ill. Hermeticity failures during TC. Case IV. Die metallization cracking during TC. and how many test cycles and parts is necessary? Case V. Wire Bond failures after life test. Case VI. Failures caused by Au/In IMC growth.

CUTSETS - MINIMAL CUT SET CALCULATION FOR DIGRAPH AND FAULT TREE RELIABILITY MODELS

NASA Technical Reports Server (NTRS)

Iverson, D. L.

1994-01-01

Fault tree and digraph models are frequently used for system failure analysis. Both type of models represent a failure space view of the system using AND and OR nodes in a directed graph structure. Fault trees must have a tree structure and do not allow cycles or loops in the graph. Digraphs allow any pattern of interconnection between loops in the graphs. A common operation performed on digraph and fault tree models is the calculation of minimal cut sets. A cut set is a set of basic failures that could cause a given target failure event to occur. A minimal cut set for a target event node in a fault tree or digraph is any cut set for the node with the property that if any one of the failures in the set is removed, the occurrence of the other failures in the set will not cause the target failure event. CUTSETS will identify all the minimal cut sets for a given node. The CUTSETS package contains programs that solve for minimal cut sets of fault trees and digraphs using object-oriented programming techniques. These cut set codes can be used to solve graph models for reliability analysis and identify potential single point failures in a modeled system. The fault tree minimal cut set code reads in a fault tree model input file with each node listed in a text format. In the input file the user specifies a top node of the fault tree and a maximum cut set size to be calculated. CUTSETS will find minimal sets of basic events which would cause the failure at the output of a given fault tree gate. The program can find all the minimal cut sets of a node, or minimal cut sets up to a specified size. The algorithm performs a recursive top down parse of the fault tree, starting at the specified top node, and combines the cut sets of each child node into sets of basic event failures that would cause the failure event at the output of that gate. Minimal cut set solutions can be found for all nodes in the fault tree or just for the top node. The digraph cut set code uses the same techniques as the fault tree cut set code, except it includes all upstream digraph nodes in the cut sets for a given node and checks for cycles in the digraph during the solution process. CUTSETS solves for specified nodes and will not automatically solve for all upstream digraph nodes. The cut sets will be output as a text file. CUTSETS includes a utility program that will convert the popular COD format digraph model description files into text input files suitable for use with the CUTSETS programs. FEAT (MSC-21873) and FIRM (MSC-21860) available from COSMIC are examples of programs that produce COD format digraph model description files that may be converted for use with the CUTSETS programs. CUTSETS is written in C-language to be machine independent. It has been successfully implemented on a Sun running SunOS, a DECstation running ULTRIX, a Macintosh running System 7, and a DEC VAX running VMS. The RAM requirement varies with the size of the models. CUTSETS is available in UNIX tar format on a .25 inch streaming magnetic tape cartridge (standard distribution) or on a 3.5 inch diskette. It is also available on a 3.5 inch Macintosh format diskette or on a 9-track 1600 BPI magnetic tape in DEC VAX FILES-11 format. Sample input and sample output are provided on the distribution medium. An electronic copy of the documentation in Macintosh Microsoft Word format is included on the distribution medium. Sun and SunOS are trademarks of Sun Microsystems, Inc. DEC, DeCstation, ULTRIX, VAX, and VMS are trademarks of Digital Equipment Corporation. UNIX is a registered trademark of AT&T Bell Laboratories. Macintosh is a registered trademark of Apple Computer, Inc.

The Genetic Challenges and Opportunities in Advanced Heart Failure

PubMed Central

Hannah-Shmouni, Fady; Seidelmann, Sara B.; Sirrs, Sandra; Mani, Arya; Jacoby, Daniel

2017-01-01

The causes of heart failure are diverse. Inherited causes represent an important clinical entity and can be divided into 2 major categories: familial and metabolic cardiomyopathies. The distinct features that might be present in early disease states can become broadly overlapping with other diseases, such as in the case of inherited cardiomyopathies (ie, familial hypertrophic cardiomyopathy or mitochondrial diseases). In this review article, we focus on genetic issues related to advanced heart failure. Because of the emerging importance of this topic and its breadth, we sought to focus our discussion on the known genetic forms of heart failure syndromes, genetic testing, and newer data on pharmacogenetics and therapeutics in the treatment of heart failure, to primarily encourage clinicians to place a priority on the diagnosis and treatment of these potentially treatable conditions. PMID:26518444

Respiratory failure in diabetic ketoacidosis.

PubMed

Konstantinov, Nikifor K; Rohrscheib, Mark; Agaba, Emmanuel I; Dorin, Richard I; Murata, Glen H; Tzamaloukas, Antonios H

2015-07-25

Respiratory failure complicating the course of diabetic ketoacidosis (DKA) is a source of increased morbidity and mortality. Detection of respiratory failure in DKA requires focused clinical monitoring, careful interpretation of arterial blood gases, and investigation for conditions that can affect adversely the respiration. Conditions that compromise respiratory function caused by DKA can be detected at presentation but are usually more prevalent during treatment. These conditions include deficits of potassium, magnesium and phosphate and hydrostatic or non-hydrostatic pulmonary edema. Conditions not caused by DKA that can worsen respiratory function under the added stress of DKA include infections of the respiratory system, pre-existing respiratory or neuromuscular disease and miscellaneous other conditions. Prompt recognition and management of the conditions that can lead to respiratory failure in DKA may prevent respiratory failure and improve mortality from DKA.

Respiratory failure in diabetic ketoacidosis

PubMed Central

Konstantinov, Nikifor K; Rohrscheib, Mark; Agaba, Emmanuel I; Dorin, Richard I; Murata, Glen H; Tzamaloukas, Antonios H

2015-01-01

Respiratory failure complicating the course of diabetic ketoacidosis (DKA) is a source of increased morbidity and mortality. Detection of respiratory failure in DKA requires focused clinical monitoring, careful interpretation of arterial blood gases, and investigation for conditions that can affect adversely the respiration. Conditions that compromise respiratory function caused by DKA can be detected at presentation but are usually more prevalent during treatment. These conditions include deficits of potassium, magnesium and phosphate and hydrostatic or non-hydrostatic pulmonary edema. Conditions not caused by DKA that can worsen respiratory function under the added stress of DKA include infections of the respiratory system, pre-existing respiratory or neuromuscular disease and miscellaneous other conditions. Prompt recognition and management of the conditions that can lead to respiratory failure in DKA may prevent respiratory failure and improve mortality from DKA. PMID:26240698

Premature ovarian failure 3 years after menarche in a 16-year-old girl following human papillomavirus vaccination.

PubMed

Little, Deirdre Therese; Ward, Harvey Rodrick Grenville

2012-09-30

Premature ovarian failure in a well adolescent is a rare event. Its occurrence raises important questions about causation, which may signal other systemic concerns. This patient presented with amenorrhoea after identifying a change from her regular cycle to irregular and scant periods following vaccinations against human papillomavirus. She declined the oral contraceptives initially prescribed for amenorrhoea. The diagnostic tasks were to determine the reason for her secondary amenorrhoea and then to investigate for possible causes of the premature ovarian failure identified. Although the cause is unknown in 90% of cases, the remaining chief identifiable causes of this condition were excluded. Premature ovarian failure was then notified as a possible adverse event following this vaccination. The young woman was counselled regarding preservation of bone density, reproductive implications and relevant follow-up. This event could hold potential implications for population health and prompts further inquiry.

Antibiotic failure mediated by a resistant subpopulation in Enterobacter cloacae

PubMed Central

Band, Victor I.; Crispell, Emily K.; Napier, Brooke A.; Herrera, Carmen M.; Tharp, Greg K.; Vavikolanu, Kranthi; Pohl, Jan; Read, Timothy D.; Bosinger, Steven E.; Trent, M. Stephen; Burd, Eileen M.; Weiss, David S.

2016-01-01

Antibiotic resistance is a major public health threat, further complicated by unexplained treatment failures caused by bacteria that appear antibiotic susceptible. We describe an Enterobacter cloacae isolate harbouring a minor subpopulation that is highly resistant to the last-line antibiotic colistin. This subpopulation was distinct from persisters, became predominant in colistin, returned to baseline after colistin removal and was dependent on the histidine kinase PhoQ. During murine infection, but in the absence of colistin, innate immune defences led to an increased frequency of the resistant subpopulation, leading to inefficacy of subsequent colistin therapy. An isolate with a lower-frequency colistin-resistant subpopulation similarly caused treatment failure but was misclassified as susceptible by current diagnostics once cultured outside the host. These data demonstrate the ability of low-frequency bacterial subpopulations to contribute to clinically relevant antibiotic resistance, elucidating an enigmatic cause of antibiotic treatment failure and highlighting the critical need for more sensitive diagnostics. PMID:27572838

Chronic sublethal stress causes bee colony failure.

PubMed

Bryden, John; Gill, Richard J; Mitton, Robert A A; Raine, Nigel E; Jansen, Vincent A A

2013-12-01

Current bee population declines and colony failures are well documented yet poorly understood and no single factor has been identified as a leading cause. The evidence is equivocal and puzzling: for instance, many pathogens and parasites can be found in both failing and surviving colonies and field pesticide exposure is typically sublethal. Here, we investigate how these results can be due to sublethal stress impairing colony function. We mathematically modelled stress on individual bees which impairs colony function and found how positive density dependence can cause multiple dynamic outcomes: some colonies fail while others thrive. We then exposed bumblebee colonies to sublethal levels of a neonicotinoid pesticide. The dynamics of colony failure, which we observed, were most accurately described by our model. We argue that our model can explain the enigmatic aspects of bee colony failures, highlighting an important role for sublethal stress in colony declines. © 2013 The Authors. Ecology Letters published by John Wiley & Sons Ltd and CNRS.

Chronic sublethal stress causes bee colony failure

PubMed Central

Bryden, John; Gill, Richard J; Mitton, Robert A A; Raine, Nigel E; Jansen, Vincent A A; Hodgson, David

2013-01-01

Current bee population declines and colony failures are well documented yet poorly understood and no single factor has been identified as a leading cause. The evidence is equivocal and puzzling: for instance, many pathogens and parasites can be found in both failing and surviving colonies and field pesticide exposure is typically sublethal. Here, we investigate how these results can be due to sublethal stress impairing colony function. We mathematically modelled stress on individual bees which impairs colony function and found how positive density dependence can cause multiple dynamic outcomes: some colonies fail while others thrive. We then exposed bumblebee colonies to sublethal levels of a neonicotinoid pesticide. The dynamics of colony failure, which we observed, were most accurately described by our model. We argue that our model can explain the enigmatic aspects of bee colony failures, highlighting an important role for sublethal stress in colony declines. PMID:24112478

Aldehyde Dehydrogenase 2 in Aplastic Anemia, Fanconi Anemia and Hematopoietic Stem Cells

PubMed Central

Van Wassenhove, Lauren D.; Mochly-Rosen, Daria; Weinberg, Kenneth I.

2016-01-01

Maintenance of the hematopoietic stem cell (HSC) compartment depends on the ability to metabolize exogenously and endogenously generated toxins, and to repair cellular damage caused by such toxins. Reactive aldehydes have been demonstrated to cause specific genotoxic injury, namely DNA interstrand cross-links. Aldehyde dehydrogenase 2 (ALDH2) is a member of a 19 isoenzyme ALDH family with different substrate specificities, subcellular localization, and patterns of expression. ALDH2 is localized in mitochondria and is essential for the metabolism of acetaldehyde, thereby placing it directly downstream of ethanol metabolism. Deficiency in ALDH2 expression and function are caused by a single nucleotide substitution and resulting amino acid change, called ALDH2*2. This genetic polymorphism affects 35–45% of East Asians (about ~560 million people), and causes the well-known Asian flushing syndrome, which results in disulfiram-like reactions after ethanol consumption. Recently, the ALDH2*2 genotype has been found to be associated with marrow failure, with both an increased risk of sporadic aplastic anemia and more rapid progression of Fanconi Anemia. This review discusses the unexpected interrelationship between aldehydes, ALDH2 and hematopoietic stem cell biology, and in particular its relationship to Fanconi anemia. PMID:27650066

Investigation of Tantalum Wet Slug Capacitor Failures in the Apollo Telescope Mount Charger Battery Regulator Modules

NASA Technical Reports Server (NTRS)

Williams, J. F.; Wiedeman, D. H.

1973-01-01

This investigation describes the capacitor failures and to identify the cause of the failure mechanism. Early failures were thought to have happened because of age and/or abuse since the failed capacitors were dated 1967. It is shown that all 1967 capacitors were replaced with 1972 capacitors.

Late Intensive Care Unit Admission in Liver Transplant Recipients: 10-Year Experience.

PubMed

Atar, Funda; Gedik, Ender; Kaplan, Şerife; Zeyneloğlu, Pınar; Pirat, Arash; Haberal, Mehmet

2015-11-01

We evaluated late intensive care unit admission in liver transplant recipients to identify incidences and causes of acute respiratory failure in the postoperative period and to compare these results with results in patients who did not have acute respiratory failure. We retrospectively screened the data of 173 consecutive adult liver transplant recipients from January 2005 through March 2015 to identify patients with late admission (> 30 d posttransplant) to an intensive care unit. Patients were divided into 2 groups: patients with and without acute respiratory failure. Acute respiratory failure was defined as severe dyspnea, respiratory distress, decreased oxygen saturation, hypoxemia or hypercapnia on room air, or need for noninvasive or invasive mechanical ventilation. Demographic, laboratory, clinical, and respiratory data were collected. Model for End-Stage Liver Disease, Acute Physiology and Chronic Health Evaluation II, and Sequential Organ Failure Assessment scores; lengths of intensive care unit and hospital stays; and hospital mortality were assessed. Among 173 patients, 37 (21.4%) were admitted to an intensive care unit, including 22 (59.5%) with acute respiratory failure. The leading cause of acute respiratory failure was pneumonia (n = 19, 86.4%). Patients with acute respiratory failure had significantly lower levels of albumin before intensive care unit admission (P = .003). In patients with acute respiratory failure, severe sepsis and septic shock were more frequently observed and tracheotomy was more frequently performed (P = .041). Acute respiratory failure developed in 59.5% of liver transplant recipients with late intensive care unit admission. The leading cause was pneumonia, with this group of patients having higher requirements for invasive mechanical ventilation and tracheotomy, longer stays in an intensive care unit, and higher mortality.

Acute Respiratory Failure in Renal Transplant Recipients: A Single Intensive Care Unit Experience.

PubMed

Ulas, Aydin; Kaplan, Serife; Zeyneloglu, Pinar; Torgay, Adnan; Pirat, Arash; Haberal, Mehmet

2015-11-01

Frequency of pulmonary complications after renal transplant has been reported to range from 3% to 17%. The objective of this study was to evaluate renal transplant recipients admitted to an intensive care unit to identify incidence and cause of acute respiratory failure in the postoperative period and compare clinical features and outcomes between those with and without acute respiratory failure. We retrospectively screened the data of 540 consecutive adult renal transplant recipients who received their grafts at a single transplant center and included those patients admitted to an intensive care unit during this period for this study. Acute respiratory failure was defined as severe dyspnea, respiratory distress, decreased oxygen saturation, hypoxemia or hypercapnia on room air, or requirement of noninvasive or invasive mechanical ventilation. Among the 540 adult renal transplant recipients, 55 (10.7%) were admitted to an intensive care unit, including 26 (47.3%) admitted for acute respiratory failure. Median time from transplant to intensive care unit admission was 10 months (range, 0-67 mo). The leading causes of acute respiratory failure were bacterial pneumonia (56%) and cardiogenic pulmonary edema (44%). Mean partial pressure of arterial oxygen to fractional inspired oxygen ratio was 174 ± 59, invasive mechanical ventilation was used in 13 patients (50%), and noninvasive mechanical ventilation was used in 8 patients (31%). The overall mortality was 16.4%. Acute respiratory failure was the reason for intensive care unit admission in almost half of our renal transplant recipients. Main causes of acute respiratory failure were bacterial pneumonia and cardiogenic pulmonary edema. Mortality of patients admitted for acute respiratory failure was similar to those without acute respiratory failure.

Sleep and memory. I: The influence of different sleep stages on memory.

PubMed

Rotenberg, V S

1992-01-01

A new approach to the sleep stages role in memory is discussed in the context of the two opposite patterns of behavior-search activity and renunciation of search. Search activity is activity designed to change the situation (or the subjects attitudes to it) in the absence of a definite forecast of the results of such activity, but with the constant consideration of these results at all stages of activity. Search activity increases general adaptability and body resistance while renunciation of search decreases adaptability and requires REM sleep for its compensation. Unprepared learning, which is often accompanied by failures on the first steps of learning, is suggested to produce renunciation of search, which decreases learning ability, suppress retention, and increase REM sleep requirement. A prolonged REM sleep deprivation before training causes learned helplessness and disturbs the learning process, while short REM sleep deprivation cause the "rebound" of the compensatory search activity that interferes with passive avoidance. REM sleep deprivation performed after a training session can increase distress caused by a training procedure, with the subsequent negative outcome on retention.

Anger, hostility, and hospitalizations in patients with heart failure.

PubMed

Keith, Felicia; Krantz, David S; Chen, Rusan; Harris, Kristie M; Ware, Catherine M; Lee, Amy K; Bellini, Paula G; Gottlieb, Stephen S

2017-09-01

Heart failure patients have a high hospitalization rate, and anger and hostility are associated with coronary heart disease morbidity and mortality. Using structural equation modeling, this prospective study assessed the predictive validity of anger and hostility traits for cardiovascular and all-cause rehospitalizations in patients with heart failure. 146 heart failure patients were administered the STAXI and Cook-Medley Hostility Inventory to measure anger, hostility, and their component traits. Hospitalizations were recorded for up to 3 years following baseline. Causes of hospitalizations were categorized as heart failure, total cardiac, noncardiac, and all-cause (sum of cardiac and noncardiac). Measurement models were separately fit for Anger and Hostility, followed by a Confirmatory Factor Analysis to estimate the relationship between the Anger and Hostility constructs. An Anger model consisted of State Anger, Trait Anger, Anger Expression Out, and Anger Expression In, and a Hostility model included Cynicism, Hostile Affect, Aggressive Responding, and Hostile Attribution. The latent construct of Anger did not predict any of the hospitalization outcomes, but Hostility significantly predicted all-cause hospitalizations. Analyses of individual trait components of each of the 2 models indicated that Anger Expression Out predicted all-cause and noncardiac hospitalizations, and Trait Anger predicted noncardiac hospitalizations. None of the individual components of Hostility were related to rehospitalizations or death. The construct of Hostility and several components of Anger are predictive of hospitalizations that were not specific to cardiac causes. Mechanisms common to a variety of health problems, such as self-care and risky health behaviors, may be involved in these associations. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Causes of Death Following Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

PubMed

Xiong, Tian-Yuan; Liao, Yan-Biao; Zhao, Zhen-Gang; Xu, Yuan-Ning; Wei, Xin; Zuo, Zhi-Liang; Li, Yi-Jian; Cao, Jia-Yu; Tang, Hong; Jilaihawi, Hasan; Feng, Yuan; Chen, Mao

2015-09-21

Transcatheter aortic valve replacement (TAVR) is an effective alternative to surgical aortic valve replacement in patients at high surgical risk. However, there is little published literature on the exact causes of death. The PubMed database was systematically searched for studies reporting causes of death within and after 30 days following TAVR. Twenty-eight studies out of 3934 results retrieved were identified. In the overall analysis, 46.4% and 51.6% of deaths were related to noncardiovascular causes within and after the first 30 days, respectively. Within 30 days of TAVR, infection/sepsis (18.5%), heart failure (14.7%), and multiorgan failure (13.2%) were the top 3 causes of death. Beyond 30 days, infection/sepsis (14.3%), heart failure (14.1%), and sudden death (10.8%) were the most common causes. All possible subgroup analyses were made. No significant differences were seen for proportions of cardiovascular deaths except the comparison between moderate (mean STS score 4 to 8) and high (mean STS score >8) -risk patients after 30 days post-TAVR (56.0% versus 33.5%, P=0.005). Cardiovascular and noncardiovascular causes of death are evenly balanced both in the perioperative period and at long-term follow-up after TAVR. Infection/sepsis and heart failure were the most frequent noncardiovascular and cardiovascular causes of death. This study highlights important areas of clinical focus that could further improve outcomes after TAVR. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Why do organizations not learn from incidents? Bottlenecks, causes and conditions for a failure to effectively learn.

PubMed

Drupsteen, Linda; Hasle, Peter

2014-11-01

If organizations would be able to learn more effectively from incidents that occurred in the past, future incidents and consequential injury or damage can be prevented. To improve learning from incidents, this study aimed to identify limiting factors, i.e. the causes of the failure to effectively learn. In seven organizations focus groups were held to discuss factors that according to employees contributed to the failure to learn. By use of a model of the learning from incidents process, the steps, where difficulties for learning arose, became visible, and the causes for these difficulties could be studied. Difficulties were identified in multiple steps of the learning process, but most difficulties became visible when planning actions, which is the phase that bridges the gap from incident investigation to actions for improvement. The main causes for learning difficulties, which were identified by the participants in this study, were tightly related to the learning process, but some indirect causes - or conditions - such as lack of ownership and limitations in expertise were also mentioned. The results illustrate that there are two types of causes for the failure to effectively learn: direct causes and indirect causes, here called conditions. By actively and systematically studying learning, more conditions might be identified and indicators for a successful learning process may be determined. Studying the learning process does, however, require a shift from learning from incidents to learning to learn. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spontaneous attentional fluctuations in impaired states and pathological conditions: a neurobiological hypothesis.

PubMed

Sonuga-Barke, Edmund J S; Castellanos, F Xavier

2007-01-01

In traditional accounts, fluctuations in sustained and focused attention and associated attentional lapses during task performance are regarded as the result of failures of top-down and effortful higher order processes. The current paper reviews an alternative hypothesis: that spontaneous patterns of very low frequency (<0.1 Hz) coherence within a specific brain network ('default-mode network') thought to support a pattern of generalized task-non-specific cognition during rest, can persist or intrude into periods of active task-specific processing, producing periodic fluctuations in attention that compete with goal-directed activity. We review recent studies supporting the existence of the resting state default network, examine the mechanism underpinning it, describe the consequent temporally distinctive effects on cognition and behaviour of default-mode interference into active processing periods, and suggest some factors that might predispose to it. Finally, we explore the putative role of default-mode interference as a cause of performance variability in attention deficit/hyperactivity disorder.

Worn is born: The role of the maxillo-mandibular relation in management of worn dentition.

PubMed

Li, Zhongjie; Yang, Zheng; Lan, Tingting; Zhao, Hanchi; Liu, Yang

2017-07-01

Worn dentition, often accompanied by occlusion changes such as reduced vertical dimension, poses a big challenge to both diagnosis and treatment. Current established causes fail to explain the observed tooth wearing patterns, and the treatments based on the documented pathogeneses are often unpredictable and require frequent maintenance. From the perspective of stomatognathic system, we postulate that the role of maxillo-mandibular relation is a crucial part in the tooth wear progression patterns, and should be well addressed in treatment planning. Incompatible occlusion with the inherent tendency of maxillo-mandibular relation has a profound effect on either wearing of natural teeth or failures of restorations. With the aid of cephalometrics and analysis of occlusion it is now possible to reduce this fallacy and achieve a harmony by re-designing the occlusion. According to our treated worn dentition cases, the restoring treatment guided by the tendency of maxillo-mandibular relation showed very promising results. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Bayesian-based two-stage inexact optimization method for supporting stream water quality management in the Three Gorges Reservoir region.

PubMed

Hu, X H; Li, Y P; Huang, G H; Zhuang, X W; Ding, X W

2016-05-01

In this study, a Bayesian-based two-stage inexact optimization (BTIO) method is developed for supporting water quality management through coupling Bayesian analysis with interval two-stage stochastic programming (ITSP). The BTIO method is capable of addressing uncertainties caused by insufficient inputs in water quality model as well as uncertainties expressed as probabilistic distributions and interval numbers. The BTIO method is applied to a real case of water quality management for the Xiangxi River basin in the Three Gorges Reservoir region to seek optimal water quality management schemes under various uncertainties. Interval solutions for production patterns under a range of probabilistic water quality constraints have been generated. Results obtained demonstrate compromises between the system benefit and the system failure risk due to inherent uncertainties that exist in various system components. Moreover, information about pollutant emission is accomplished, which would help managers to adjust production patterns of regional industry and local policies considering interactions of water quality requirement, economic benefit, and industry structure.

The survival-reproduction association becomes stronger when conditions are good.

PubMed

Robert, Alexandre; Bolton, Mark; Jiguet, Frédéric; Bried, Joël

2015-11-07

Positive covariations between survival and reproductive performance (S-R covariation) are generally interpreted in the context of fixed or dynamic demographic heterogeneity (i.e. persistent differences between individuals, or dynamic variation in resource acquisition), but the processes underlying covariations are still unknown. We used multi-event modelling to investigate how environmental and individual features influence S-R covariation patterns in a long-lived seabird, the Monteiro's storm petrel (Oceanodroma monteiroi). Our analysis reveals that a strong positive association between individual breeding success and subsequent survival occurs only when conditions are favourable to reproduction (in favourable years, in high-quality nests and in nest-faithful breeders). This finding reflects differences in the main causes of breeding failure and mortality under favourable and unfavourable conditions, which in turn lead to distinct patterns of S-R covariation. We suggest, in particular, that resource-related sources of demographic heterogeneity do not generate a strong S-R covariation, in contrast with hidden and unpredictable sources of variation. © 2015 The Author(s).

A//r//m//s AND SEISMIC SOURCE STUDIES.

USGS Publications Warehouse

Hanks, T.C.; ,

1984-01-01

This paper briefly summarizes some recent developments in studies of seismic source parameter estimation, emphasizing the essential similarities between mining-induced seismogenic-failure and naturally occurring, tectonically driven earthquakes. The root-mean-square acceleration, a//r//m//s, shows much promise as an observational measure of high-frequency ground motion; it is very stable observationally, is insensitive to radiation pattern, and can be related linearly to the dynamic stress differences arising in the faulting process. To interpret a//r//m//s correctly, however, requires knowledge of f//m//a//x, the high-frequency band-limitation of the radiated field of earthquakes. As a practical matter, f//m//a//x can be due to any number of causes, but an essential ambiguity is whether or not f//m//a//x can arise from source properties alone. The interaction of the aftershocks of the Oroville, California, earthquake illustrates how a//r//m//s stress drops may be connected to detailed seismicity patterns.

Restoration of Pattern Recognition Receptor Costimulation to Treat Chromoblastomycosis, a Chronic Fungal Infection of the Skin

PubMed Central

da Glória Sousa, Maria; Reid, Delyth M.; Schweighoffer, Edina; Tybulewicz, Victor; Ruland, Jürgen; Langhorne, Jean; Yamasaki, Sho; Taylor, Philip R.; Almeida, Sandro R.; Brown, Gordon D.

2011-01-01

Summary Chromoblastomycosis is a chronic skin infection caused by the fungus Fonsecaea pedrosoi. Exploring the reasons underlying the chronic nature of F. pedrosoi infection in a murine model of chromoblastomycosis, we find that chronicity develops due to a lack of pattern recognition receptor (PRR) costimulation. F. pedrosoi was recognized primarily by C-type lectin receptors (CLRs), but not by Toll-like receptors (TLRs), which resulted in the defective induction of proinflammatory cytokines. Inflammatory responses to F. pedrosoi could be reinstated by TLR costimulation, but also required the CLR Mincle and signaling via the Syk/CARD9 pathway. Importantly, exogenously administering TLR ligands helped clear F. pedrosoi infection in vivo. These results demonstrate how a failure in innate recognition can result in chronic infection, highlight the importance of coordinated PRR signaling, and provide proof of the principle that exogenously applied PRR agonists can be used therapeutically. PMID:21575914

Multiple imputation methods for nonparametric inference on cumulative incidence with missing cause of failure

PubMed Central

Lee, Minjung; Dignam, James J.; Han, Junhee

2014-01-01

We propose a nonparametric approach for cumulative incidence estimation when causes of failure are unknown or missing for some subjects. Under the missing at random assumption, we estimate the cumulative incidence function using multiple imputation methods. We develop asymptotic theory for the cumulative incidence estimators obtained from multiple imputation methods. We also discuss how to construct confidence intervals for the cumulative incidence function and perform a test for comparing the cumulative incidence functions in two samples with missing cause of failure. Through simulation studies, we show that the proposed methods perform well. The methods are illustrated with data from a randomized clinical trial in early stage breast cancer. PMID:25043107

Causes of chronic orthostatic hypotension

NASA Technical Reports Server (NTRS)

Robertson, D.; Robertson, R. M.

1994-01-01

OBJECTIVE: To determine the frequency of various causes of orthostatic hypotension. DESIGN: Survey. SETTING: Tertiary referral center. PATIENTS: One hundred patients with moderate to severe orthostatic hypotension. RESULTS: Twenty-seven percent of the patients had primary autonomic failure, 35% had secondary autonomic failure, and 38% had hypotension without evidence of generalized autonomic degeneration. CONCLUSIONS: In a tertiary referral center, only a minority of patients with severe orthostatic hypotension will have Shy-Drager syndrome or Bradbury-Eggleston syndrome as their primary disease. Occasional patients who initially appear to have Bradbury-Eggleston syndrome ultimately prove to have Shy-Drager syndrome or paraneoplastic autonomic failure. Antidepressant drugs, even in low doses, remain a major overlooked cause of orthostatic hypotension.

Technical complications of implant-causes and management: A comprehensive review

PubMed Central

Gupta, Swati; Gupta, Hemant; Tandan, Amrit

2015-01-01

Given the increasing popularity of dental implants, the number of failures due to late implant fracture is also expected to increase. Hence, the scope for prevention and management needs to be emphasized. The objective of this review article is to analyze the various causes of failure of dental implants due to implant fixture/abutment screw fractures and also to enumerate the management and the preventive options for these failures, thereby aiming to help the clinicians to properly plan the implant-supported prosthesis treatment by considering the important biomechanical aspects of this type of rehabilitation. The present review emphasizes the causes and management of technical complications and not the incidence of such complications. PMID:26668445

Reliability Growth of Tactical Coolers at CMC Electronics Cincinnati: 1/5-Watt Cooler Test Report

NASA Astrophysics Data System (ADS)

Kuo, D. T.; Lody, T. D.

2004-06-01

CMC Electronics Cincinnati (CMC) is conducting a reliability growth program to extend the life of tactical Stirling-cycle cryocoolers. The continuous product improvement processes consist of testing production coolers to failure, determining the root cause, incorporating improvements and verification. The most recent life data for the 1/5-Watt Cooler (Model B512B) is presented with a discussion of leading root causes and potential improvements. The mean time to failure (MTTF) life of the coolers was found to be 22,552 hours with the root cause of failure attributed to the accumulation of methane and carbon dioxide in the cooler and the wear of the piston.

Failure Atlas for Rolling Bearings in Wind Turbines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tallian, T. E.

2006-01-01

This Atlas is structured as a supplement to the book: T.E. Tallian: Failure Atlas for Hertz Contact Machine Elements, 2nd edition, ASME Press New York, (1999). The content of the atlas comprises plate pages from the book that contain bearing failure images, application data, and descriptions of failure mode, image, and suspected failure causes. Rolling bearings are a critical component of the mainshaft system, gearbox and generator in the rapidly developing technology of power generating wind turbines. The demands for long service life are stringent; the design load, speed and temperature regimes are demanding and the environmental conditions including weather,more » contamination, impediments to monitoring and maintenance are often unfavorable. As a result, experience has shown that the rolling bearings are prone to a variety of failure modes that may prevent achievement of design lives. Morphological failure diagnosis is extensively used in the failure analysis and improvement of bearing operation. Accumulated experience shows that the failure appearance and mode of failure causation in wind turbine bearings has many distinguishing features. The present Atlas is a first effort to collect an interpreted database of specifically wind turbine related rolling bearing failures and make it widely available. This Atlas is structured as a supplement to the book: T. E. Tallian: Failure Atlas for Hertz Contact Machine Elements, 2d edition, ASME Press New York, (1999). The main body of that book is a comprehensive collection of self-contained pages called Plates, containing failure images, bearing and application data, and three descriptions: failure mode, image and suspected failure causes. The Plates are sorted by main failure mode into chapters. Each chapter is preceded by a general technical discussion of the failure mode, its appearance and causes. The Plates part is supplemented by an introductory part, describing the appearance classification and failure classification systems used, and by several indexes. The present Atlas is intended as a supplement to the book. It has the same structure but contains only Plate pages, arranged in chapters, each with a chapter heading page giving a short definition of the failure mode illustrated. Each Plate page is self contained, with images, bearing and application data, and descriptions of the failure mode, the images and the suspected causes. Images are provided in two resolutions: The text page includes 6 by 9 cm images. In addition, high resolution image files are attached, to be retrieved by clicking on their 'push pin' icon. While the material in the present Atlas is self-contained, it is nonetheless a supplement to the book and the complete interpretation of the terse image descriptions and of the system underlying the failure code presupposes familiarity with the book. Since this Atlas is a supplement to the book, its chapter numbering follows that of the book. Not all failure modes covered in the book have been found among the observed wind turbines. For that reason, and because of the omission of introductory matter, the chapter numbers in this Atlas are not a continuous sequence.« less

A New Kinematic Model for Polymodal Faulting: Implications for Fault Connectivity

NASA Astrophysics Data System (ADS)

Healy, D.; Rizzo, R. E.

2015-12-01

Conjugate, or bimodal, fault patterns dominate the geological literature on shear failure. Based on Anderson's (1905) application of the Mohr-Coulomb failure criterion, these patterns have been interpreted from all tectonic regimes, including normal, strike-slip and thrust (reverse) faulting. However, a fundamental limitation of the Mohr-Coulomb failure criterion - and others that assume faults form parallel to the intermediate principal stress - is that only plane strain can result from slip on the conjugate faults. However, deformation in the Earth is widely accepted as being three-dimensional, with truly triaxial stresses and strains. Polymodal faulting, with three or more sets of faults forming and slipping simultaneously, can generate three-dimensional strains from truly triaxial stresses. Laboratory experiments and outcrop studies have verified the occurrence of the polymodal fault patterns in nature. The connectivity of polymodal fault networks differs significantly from conjugate fault networks, and this presents challenges to our understanding of faulting and an opportunity to improve our understanding of seismic hazards and fluid flow. Polymodal fault patterns will, in general, have more connected nodes in 2D (and more branch lines in 3D) than comparable conjugate (bimodal) patterns. The anisotropy of permeability is therefore expected to be very different in rocks with polymodal fault patterns in comparison to conjugate fault patterns, and this has implications for the development of hydrocarbon reservoirs, the genesis of ore deposits and the management of aquifers. In this contribution, I assess the published evidence and models for polymodal faulting before presenting a novel kinematic model for general triaxial strain in the brittle field.

Skin Cancer of the Head and Neck With Perineural Invasion: Defining the Clinical Target Volumes Based on the Pattern of Failure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gluck, Iris; Ibrahim, Mohannad; Popovtzer, Aron

2009-05-01

Purpose: To analyze patterns of failure in patients with head-and-neck cutaneous squamous cell carcinoma (HNCSCC) and clinical/radiologic evidence of perineural invasion (CPNI), in order to define neural clinical target volume (CTV) for treatment planning. Methods and Materials: Patients treated with three-dimensional (3D) conformal or intensity-modulated radiotherapy (IMRT) for HNCSCC with CPNI were included in the study. A retrospective review of the clinical charts, radiotherapy (RT) plans and radiologic studies has been conducted. Results: Eleven consecutive patients with HNCSCCs with CPNI were treated from 2000 through 2007. Most patients underwent multiple surgical procedures and RT courses. The most prevalent failure patternmore » was along cranial nerves (CNs), and multiple CNs were ultimately involved in the majority of cases. In all cases the involved CNs at recurrence were the main nerves innervating the primary tumor sites, as well as their major communicating nerves. We have found several distinct patterns of disease spread along specific CNs depending on the skin regions harboring the primary tumors, including multiple branches of CN V and VII. These patterns and the pertinent anatomy are detailed in the this article. Conclusions: Predictable disease spread patterns along cranial nerves supplying the primary tumor sites were found in this study. Awareness of these patterns, as well as knowledge of the relevant cranial nerve anatomy, should be the basis for CTV definition and delineation for RT treatment planning.« less

Mitochondria and heart failure.

PubMed

Murray, Andrew J; Edwards, Lindsay M; Clarke, Kieran

2007-11-01

Energetic abnormalities in cardiac and skeletal muscle occur in heart failure and correlate with clinical symptoms and mortality. It is likely that the cellular mechanism leading to energetic failure involves mitochondrial dysfunction. Therefore, it is crucial to elucidate the causes of mitochondrial myopathy, in order to improve cardiac and skeletal muscle function, and hence quality of life, in heart failure patients. Recent studies identified several potential stresses that lead to mitochondrial dysfunction in heart failure. Chronically elevated plasma free fatty acid levels in heart failure are associated with decreased metabolic efficiency and cellular insulin resistance. Tissue hypoxia, resulting from low cardiac output and endothelial impairment, can lead to oxidative stress and mitochondrial DNA damage, which in turn causes dysfunction and loss of mitochondrial mass. Therapies aimed at protecting mitochondrial function have shown promise in patients and animal models with heart failure. Despite current therapies, which provide substantial benefit to patients, heart failure remains a relentlessly progressive disease, and new approaches to treatment are necessary. Novel pharmacological agents are needed that optimize substrate metabolism and maintain mitochondrial integrity, improve oxidative capacity in heart and skeletal muscle, and alleviate many of the clinical symptoms associated with heart failure.

Ferrographic and spectrometer oil analysis from a failed gas turbine engine

NASA Technical Reports Server (NTRS)

Jones, W. R., Jr.

1982-01-01

An experimental gas turbine engine was destroyed as a result of the combustion of its titanium components. It was concluded that a severe surge may have caused interference between rotating and stationary compressor that either directly or indirectly ignited the titanium components. Several engine oil samples (before and after the failure) were analyzed with a Ferrograph, a plasma, an atomic absorption, and an emission spectrometer to see if this information would aid in the engine failure diagnosis. The analyses indicated that a lubrication system failure was not a causative factor in the engine failure. Neither an abnormal wear mechanism nor a high level of wear debris was detected in the engine oil sample taken just prior to the test in which the failure occurred. However, low concentrations (0.2 to 0.5 ppm) of titanium were evident in this sample and samples taken earlier. After the failure, higher titanium concentrations ( 2 ppm) were detected in oil samples taken from different engine locations. Ferrographic analysis indicated that most of the titanium was contained in spherical metallic debris after the failure. The oil analyses eliminated a lubrication system bearing or shaft seal failure as the cause of the engine failure.

Identification of priorities for medication safety in neonatal intensive care.

PubMed

Kunac, Desireé L; Reith, David M

2005-01-01

Although neonates are reported to be at greater risk of medication error than infants and older children, little is known about the causes and characteristics of error in this patient group. Failure mode and effects analysis (FMEA) is a technique used in industry to evaluate system safety and identify potential hazards in advance. The aim of this study was to identify and prioritize potential failures in the neonatal intensive care unit (NICU) medication use process through application of FMEA. Using the FMEA framework and a systems-based approach, an eight-member multidisciplinary panel worked as a team to create a flow diagram of the neonatal unit medication use process. Then by brainstorming, the panel identified all potential failures, their causes and their effects at each step in the process. Each panel member independently rated failures based on occurrence, severity and likelihood of detection to allow calculation of a risk priority score (RPS). The panel identified 72 failures, with 193 associated causes and effects. Vulnerabilities were found to be distributed across the entire process, but multiple failures and associated causes were possible when prescribing the medication and when preparing the drug for administration. The top ranking issue was a perceived lack of awareness of medication safety issues (RPS score 273), due to a lack of medication safety training. The next highest ranking issues were found to occur at the administration stage. Common potential failures related to errors in the dose, timing of administration, infusion pump settings and route of administration. Perceived causes were multiple, but were largely associated with unsafe systems for medication preparation and storage in the unit, variable staff skill level and lack of computerised technology. Interventions to decrease medication-related adverse events in the NICU should aim to increase staff awareness of medication safety issues and focus on medication administration processes.

Automatically Detecting Failures in Natural Language Processing Tools for Online Community Text.

PubMed

Park, Albert; Hartzler, Andrea L; Huh, Jina; McDonald, David W; Pratt, Wanda

2015-08-31

The prevalence and value of patient-generated health text are increasing, but processing such text remains problematic. Although existing biomedical natural language processing (NLP) tools are appealing, most were developed to process clinician- or researcher-generated text, such as clinical notes or journal articles. In addition to being constructed for different types of text, other challenges of using existing NLP include constantly changing technologies, source vocabularies, and characteristics of text. These continuously evolving challenges warrant the need for applying low-cost systematic assessment. However, the primarily accepted evaluation method in NLP, manual annotation, requires tremendous effort and time. The primary objective of this study is to explore an alternative approach-using low-cost, automated methods to detect failures (eg, incorrect boundaries, missed terms, mismapped concepts) when processing patient-generated text with existing biomedical NLP tools. We first characterize common failures that NLP tools can make in processing online community text. We then demonstrate the feasibility of our automated approach in detecting these common failures using one of the most popular biomedical NLP tools, MetaMap. Using 9657 posts from an online cancer community, we explored our automated failure detection approach in two steps: (1) to characterize the failure types, we first manually reviewed MetaMap's commonly occurring failures, grouped the inaccurate mappings into failure types, and then identified causes of the failures through iterative rounds of manual review using open coding, and (2) to automatically detect these failure types, we then explored combinations of existing NLP techniques and dictionary-based matching for each failure cause. Finally, we manually evaluated the automatically detected failures. From our manual review, we characterized three types of failure: (1) boundary failures, (2) missed term failures, and (3) word ambiguity failures. Within these three failure types, we discovered 12 causes of inaccurate mappings of concepts. We used automated methods to detect almost half of 383,572 MetaMap's mappings as problematic. Word sense ambiguity failure was the most widely occurring, comprising 82.22% of failures. Boundary failure was the second most frequent, amounting to 15.90% of failures, while missed term failures were the least common, making up 1.88% of failures. The automated failure detection achieved precision, recall, accuracy, and F1 score of 83.00%, 92.57%, 88.17%, and 87.52%, respectively. We illustrate the challenges of processing patient-generated online health community text and characterize failures of NLP tools on this patient-generated health text, demonstrating the feasibility of our low-cost approach to automatically detect those failures. Our approach shows the potential for scalable and effective solutions to automatically assess the constantly evolving NLP tools and source vocabularies to process patient-generated text.

The Relationship of Self-Concept to Causal Attributions.

ERIC Educational Resources Information Center

Shaha, Steven H.

When people experience failures they search for an explanation of why the failure occurred. The process of seeking an explanatory cause is the basis of attribution theory. Causal attributions include the dimensions of locus of causality (internal or external), stability of the cause over time, and the degree of personal control over the outcome.…

The Effect of Cavity Design on Fracture Resistance and Failure Pattern in Monolithic Zirconia Partial Coverage Restorations - An In vitro Study.

PubMed

Harsha, Madhavareddy Sri; Praffulla, Mynampati; Babu, Mandava Ramesh; Leneena, Gudugunta; Krishna, Tejavath Sai; Divya, G

2017-05-01

Cavity preparations of posterior teeth have been frequently associated with decreased fracture strength of the teeth. Choosing the correct indirect restoration and the cavity design when restoring the posterior teeth i.e., premolars was difficult as it involves aesthetic, biomechanical and anatomical considerations. To evaluate the fracture resistance and failure pattern of three different cavity designs restored with monolithic zirconia. Human maxillary premolars atraumatically extracted for orthodontic reasons were chosen. A total of 40 teeth were selected and divided into four groups (n=10). Group I-Sound teeth (control with no preparation). Group II-MOD Inlay, Group III-Partial Onlay, Group IV-Complete Onlay. Restorations were fabricated with monolithic partially sintered zirconia CAD (SAGEMAX- NexxZr). All the 30 samples were cemented using Multilink Automix (Ivoclar) and subjected to fracture resistance testing using Universal Testing Machine (UTM) (Instron) with a steel ball of 3.5 mm diameter at crosshead speed of 0.5 mm/minute. Stereomicroscope was used to evaluate the modes of failure of the fractured specimen. Fracture resistance was tested using parametric one way ANOVA test, unpaired t-test and Tukey test. Fracture patterns were assessed using non-parametric Chi-square test. Group IV (Complete Onlay) presented highest fracture resistance and showed statistical significant difference. Group II (MOD Inlay) and Group III (Partial Onlay) showed significantly lower values than the Group I (Sound teeth). However, Groups I, II and III presented no significant difference from each other. Coming to the modes of failure, Group II (MOD Inlay) and Group III (Partial Onlay) presented mixed type of failures; Group IV (Complete Onlay) demonstrated 70% Type I failures. Of the three cavity designs evaluated, Complete Onlay had shown a significant increase in the fracture resistance than the Sound teeth.

Squamous Cell Carcinoma of the Anal Canal: Patterns and Predictors of Failure and Implications for Intensity-Modulated Radiation Treatment Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wright, Jean L., E-mail: jwright3@med.miami.ed; Patil, Sujata M.; Temple, Larissa K.F.

2010-11-15

Purpose: Intensity-modulated radiation treatment (IMRT) is increasingly used in the treatment of squamous cell carcinoma of the anal canal (SCCAC). Prevention of locoregional failure (LRF) using IMRT requires appropriate clinical target volume (CTV) definition. To better define the CTV for IMRT, we evaluated patterns and predictors of LRF in SCCAC patients given conventional radiation treatment. Methods and Materials: We reviewed records of 180 SCCAC patients treated with conventional radiation with or without chemotherapy at our institution between January 1990 and March 2007. All patients received radiation; the median primary tumor dose was 45 Gy. A total of 173 patients alsomore » received mitomycin-based chemotherapy. Results: Median follow-up was 40 months. Actuarial 3-year colostomy-free survival was 89% and overall survival (OS) 88%. Actuarial 3-year LRF was 23%. A total of 45 patients had LRF, with 35 (78%) occurring locally in the primary site (25 local only, 10 local and regional); however, 20 (44%) had regional components of failure within the pelvis or inguinal nodes (10 regional only, 10 local and regional). Cumulative sites of LRF (patients may have one or more site of failure) were as follows: primary, 35; inguinal, 8; external perianal, 5; common iliac, 4; presacral, 3; distal rectum, 2; external iliac, 2; and internal iliac, 2. All patients with common iliac failure had cT3 or N+ disease. Conclusions: The observed patterns of failure support inclusion of the inguinal and all pelvic nodal groups in the CTV for IMRT. In patients with advanced tumor or nodal stage, common iliac nodes should also be included in the CTV.« less

Tau, amyloid, and cascading network failure across the Alzheimer's disease spectrum.

PubMed

Jones, David T; Graff-Radford, Jonathan; Lowe, Val J; Wiste, Heather J; Gunter, Jeffrey L; Senjem, Matthew L; Botha, Hugo; Kantarci, Kejal; Boeve, Bradley F; Knopman, David S; Petersen, Ronald C; Jack, Clifford R

2017-12-01

Functionally related brain regions are selectively vulnerable to Alzheimer's disease pathophysiology. However, molecular markers of this pathophysiology (i.e., beta-amyloid and tau aggregates) have discrepant spatial and temporal patterns of progression within these selectively vulnerable brain regions. Existing reductionist pathophysiologic models cannot account for these large-scale spatiotemporal inconsistencies. Within the framework of the recently proposed cascading network failure model of Alzheimer's disease, however, these large-scale patterns are to be expected. This model postulates the following: 1) a tau-associated, circumscribed network disruption occurs in brain regions specific to a given phenotype in clinically normal individuals; 2) this disruption can trigger phenotype independent, stereotypic, and amyloid-associated compensatory brain network changes indexed by changes in the default mode network; 3) amyloid deposition marks a saturation of functional compensation and portends an acceleration of the inciting phenotype specific, and tau-associated, network failure. With the advent of in vivo molecular imaging of tau pathology, combined with amyloid and functional network imaging, it is now possible to investigate the relationship between functional brain networks, tau, and amyloid across the disease spectrum within these selectively vulnerable brain regions. In a large cohort (n = 218) spanning the Alzheimer's disease spectrum from young, amyloid negative, cognitively normal subjects to Alzheimer's disease dementia, we found several distinct spatial patterns of tau deposition, including 'Braak-like' and 'non-Braak-like', across functionally related brain regions. Rather than arising focally and spreading sequentially, elevated tau signal seems to occur system-wide based on inferences made from multiple cross-sectional analyses we conducted looking at regional patterns of tau signal. Younger age-of-disease-onset was associated with 'non-Braak-like' patterns of tau, suggesting an association with atypical clinical phenotypes. As predicted by the cascading network failure model of Alzheimer's disease, we found that amyloid is a partial mediator of the relationship between functional network failure and tau deposition in functionally connected brain regions. This study implicates large-scale brain networks in the pathophysiology of tau deposition and offers support to models incorporating large-scale network physiology into disease models linking tau and amyloid, such as the cascading network failure model of Alzheimer's disease. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Finite Element Creep-Fatigue Analysis of a Welded Furnace Roll for Identifying Failure Root Cause

NASA Astrophysics Data System (ADS)

Yang, Y. P.; Mohr, W. C.

2015-11-01

Creep-fatigue induced failures are often observed in engineering components operating under high temperature and cyclic loading. Understanding the creep-fatigue damage process and identifying failure root cause are very important for preventing such failures and improving the lifetime of engineering components. Finite element analyses including a heat transfer analysis and a creep-fatigue analysis were conducted to model the cyclic thermal and mechanical process of a furnace roll in a continuous hot-dip coating line. Typically, the roll has a short life, <1 year, which has been a problem for a long time. The failure occurred in the weld joining an end bell to a roll shell and resulted in the complete 360° separation of the end bell from the roll shell. The heat transfer analysis was conducted to predict the temperature history of the roll by modeling heat convection from hot air inside the furnace. The creep-fatigue analysis was performed by inputting the predicted temperature history and applying mechanical loads. The analysis results showed that the failure was resulted from a creep-fatigue mechanism rather than a creep mechanism. The difference of material properties between the filler metal and the base metal is the root cause for the roll failure, which induces higher creep strain and stress in the interface between the weld and the HAZ.

Shunting for hydrocephalus: analysis of techniques and failure patterns.

PubMed

Nigim, Fares; Critchlow, Jonathan F; Schneider, Benjamin E; Chen, Clark; Kasper, Ekkehard M

2014-09-01

Hydrocephalus is characterized by ventricular dilatation because of progressive accumulation of cerebrospinal fluid. Normal pressure hydrocephalus (NPH) affects a subset of patients representing a reversible clinical triad of gait disturbance, urinary incontinence, and dementia with normal cerebrospinal fluid pressure and composition. Various shunting procedures have been used for treatment, but techniques and outcomes remain under debate. The objective of this study was to evaluate the clinical outcomes of 232 patients with and without NPH after the first-time Ventriculoperitoneal shunt placement and assessed patterns of failure between December 2004 and December 2012. Mean age was 54.7 y in non-NPH and 71.9 y in NPH patients. We used open technique in 34.3% and laparoscopic technique in 65.7% of NPH patients and 32.7% and 67.3% of the non-NPH patients, respectively. A total of 36 of 232 patients displayed shunt failure, 16.4% in NPH and 15.2% in non-NPH patients. Twenty-three of 155 patients failed after laparoscopic and 13 of 77 failed after open placement. Proximal shunt failure was more frequent in the non-NPH cohort. Distal failures accounted for 13 of 232 cases, and the difference between laparoscopic (six of 155) and open failures (seven of 77) was profound, but not between NPH- and non-NPH patients. Shunt failures are related to the placement method. Non-NPH patients showed more proximal failures. NPH patients showed fewer proximal failures. Less distal failures were observed after laparoscopic ventriculoperitoneal shunt placement without significant differences between NPH and non-NPH patients. Beyond this, laparoscopic surgery carries distinct advantages such as shorter operating room times and hospital stays, which should translate into less use of pain medications, earlier mobilization, and a lower incidence of ileus. Copyright © 2014 Elsevier Inc. All rights reserved.

ATM CMG bearing failure analysis

NASA Technical Reports Server (NTRS)

1975-01-01

The cause or causes for the failure of ATM CMG S/N 5 (Skylab 1) and the anomalies associated with ATM CMG S/N 6 (Skylab 2) were investigated. Skylab telemetry data were reviewed and presented in the form of parameter distributions. The theory that the problems were caused by marginal bearing lubrication was studied along with the effects of orbital conditions on lubricants. Bearing tests were performed to investigate the effect of lubricant or lack of lubricant in the ATM CMG bearings and the dispersion and migration of the lubricant. The vacuum and weightless conditions of space were simulated in the bearing tests. Analysis of the results of the tests conducted points to inadequate lubrication as the predominant factor causing the failure of ATM CMG S/N 5 (Skylab 1) and the anomalies associated with ATM CMG S/N 6 (Skylab 2).

Complications Requiring Hospital Admission and Causes of In-Hospital Death over Time in Alcoholic and Nonalcoholic Cirrhosis Patients.

PubMed

Kim, Hee Yeon; Kim, Chang Wook; Choi, Jong Young; Lee, Chang Don; Lee, Sae Hwan; Kim, Moon Young; Jang, Byoung Kuk; Wo, Hyun Young

2016-01-01

Data on the epidemiology of alcoholic cirrhosis, especially in Asian countries, are limited. We compared the temporal evolution of patterns of alcoholic and nonalcoholic cirrhosis over the last decade. We retrospectively examined the inpatient datasets of five referral centers during 2002 and 2011. The study included patients who were admitted due to specific complications of liver cirrhosis. We compared the causes of hospital admissions and in-hospital deaths between patients with alcoholic and nonalcoholic cirrhosis. Among the included 2,799 hospitalizations (2,165 patients), 1,496 (1,143 patients) were from 2002, and 1,303 (1,022 patients) were from 2011. Over time, there was a reduction in the rate of hepatic encephalopathy (HE) as a cause of hospitalization and an increase in the rate of hepatocellular carcinoma. Deaths that were attributable to HE or spontaneous bacterial peritonitis (SBP) significantly decreased, whereas those due to hepatorenal syndrome (HRS) significantly increased over time in patients with alcoholic cirrhosis. However, in patients with nonalcoholic cirrhosis, hepatic failure and HRS remained the principal causes of in-hospital death during both time periods. The major causes of in-hospital deaths have evolved from acute cirrhotic complications, including HE or SBP to HRS in alcoholic cirrhosis, whereas those have remained unchanged in nonalcoholic cirrhosis during the last decade.

Coupled Electro-Thermal Simulations of Single Event Burnout in Power Diodes

NASA Astrophysics Data System (ADS)

Albadri, A. M.; Schrimpf, R. D.; Walker, D. G.; Mahajan, S. V.

2005-12-01

Power diodes may undergo destructive failures when they are struck by high-energy particles during the off state (high reverse-bias voltage). This paper describes the failure mechanism using a coupled electro-thermal model. The specific case of a 3500-V diode is considered and it is shown that the temperatures reached when high voltages are applied are sufficient to cause damage to the constituent materials of the diode. The voltages at which failure occurs (e.g., 2700 V for a 17-MeV carbon ion) are consistent with previously reported data. The simulation results indicate that the catastrophic failures result from local heating caused by avalanche multiplication of ion-generated carriers.

Acute-on-chronic and Decompensated Chronic Liver Failure: Definitions, Epidemiology, and Prognostication.

PubMed

Olson, Jody C

2016-07-01

Chronic liver disease is the fifth leading cause of death worldwide and represents a major burden for the health care community. Cirrhosis is a progressive disease resulting in end-stage liver failure, which in the absence of liver transplantation is fatal. Acute-on-chronic liver failure carries high short-term mortality but is potentially reversible. Viral hepatitis, alcohol, and nonalcoholic fatty liver disease remain the principal causes of liver disease. Though treatments exist for hepatitis B and C, they remain unavailable to many with these diseases. This article reviews the epidemiology of advanced liver disease and the concept of acute-on-chronic liver failure. Copyright © 2016 Elsevier Inc. All rights reserved.

Anastomotic fibrous ring as cause of stricture recurrence after bulbar onlay graft urethroplasty.

PubMed

Barbagli, Guido; Guazzoni, Giorgio; Palminteri, Enzo; Lazzeri, Massimo

2006-08-01

We retrospectively reviewed patterns of failure after bulbar substitution urethroplasty. In particular we investigated the prevalence and location of anastomotic fibrous ring strictures occurring at the apical anastomoses between the graft and urethral plate after 3 types of onlay graft techniques. We reviewed the records of 107 patients who underwent bulbar urethroplasty between 1994 and 2004. Mean patient age was 44 years. Patients with lichen sclerosus, failed hypospadias repair or urethroplasty and panurethral strictures were excluded. A total of 45 patients underwent dorsal onlay skin graft urethroplasty, 50 underwent buccal mucosa onlay graft urethroplasty and 12 underwent augmented end-to-end urethroplasty. The clinical outcome was considered a success or failure at the time that any postoperative procedure was needed, including dilation. Mean followup was 74 months (range 12 to 130). Of 107 cases 85 (80%) were successful and 22 (20%) failed. Failure in 12 patients (11%) involved the whole grafted area and in 10 (9%) it involved the anastomotic site, which was distal and proximal in 5 each. Urethrography, urethral ultrasound and urethroscopy were fundamental for determining the difference between full-length and focal extension of re-stricture. Failures were treated with multistage urethroplasty in 12 cases, urethrotomy in 7 and 1-stage urethroplasty in 3. Of the patients 16 had a satisfactory final outcome and 6 underwent definitive perineal urinary diversion. The prevalence and location of anastomotic ring strictures after bulbar urethroplasty were uniformly distributed in after 3 surgical techniques using skin or buccal mucosa. Further studies are necessary to clarify the etiology of these fibrous ring strictures.

Amyotrophic lateral sclerosis (ALS), a novel rare cause of elevated plasma troponin T levels.

PubMed

Von Lueder, Thomas G; Melsom, Morten Nissen; Atar, Dan; Agewall, Stefan

2011-01-01

In this article, we report on a patient with chronic and modestly elevated plasma troponin T (TnT) levels and frequent hospitalizations following the first admission until his death one year later. The patient was initially admitted for dyspnea and discharged from hospital with a diagnosis of non-ST elevation acute myocardial infarction (AMI). Coronary angiography and echocardiography were normal, but the patient received the (false) diagnosis of AMI at two further admissions, based purely on elevated TnT. Shortly thereafter, severe respiratory failure with restrictive-type spirometry pattern became the predominant clinical symptom, with constantly elevated TnT levels at frequent re-admissions. Due to inconsistent follow-up by primarily junior and non-specialist staff at a number of different wards, pulmonary function tests and previous smoking history were mis-interpreted as typical of chronic obstructive pulmonary disease (COPD). The patient received standard COPD treatment without any improvement. After a year of gradually worsening respiratory failure and repeated hospitalizations, thorough assessment by a pulmonologist and neurologist established the final diagnosis of amyotrophic lateral sclerosis (ALS). The patient died shortly thereafter. While progressive respiratory failure is well-known to determine morbidity and mortality in patients with ALS, chronically elevated TnT levels in the absence of coronary artery disease have, to our best knowledge, not been described so far. We suggest that chronic myocardial hypoxia due to ALS-related hypoxic respiratory failure was the most likely underlying etiology for the elevated TnT levels seen here but other mechanism such as immune-mediated myocardial injury cannot be excluded.

Reducing error and improving efficiency during vascular interventional radiology: implementation of a preprocedural team rehearsal.

PubMed

Morbi, Abigail H M; Hamady, Mohamad S; Riga, Celia V; Kashef, Elika; Pearch, Ben J; Vincent, Charles; Moorthy, Krishna; Vats, Amit; Cheshire, Nicholas J W; Bicknell, Colin D

2012-08-01

To determine the type and frequency of errors during vascular interventional radiology (VIR) and design and implement an intervention to reduce error and improve efficiency in this setting. Ethical guidance was sought from the Research Services Department at Imperial College London. Informed consent was not obtained. Field notes were recorded during 55 VIR procedures by a single observer. Two blinded assessors identified failures from field notes and categorized them into one or more errors by using a 22-part classification system. The potential to cause harm, disruption to procedural flow, and preventability of each failure was determined. A preprocedural team rehearsal (PPTR) was then designed and implemented to target frequent preventable potential failures. Thirty-three procedures were observed subsequently to determine the efficacy of the PPTR. Nonparametric statistical analysis was used to determine the effect of intervention on potential failure rates, potential to cause harm and procedural flow disruption scores (Mann-Whitney U test), and number of preventable failures (Fisher exact test). Before intervention, 1197 potential failures were recorded, of which 54.6% were preventable. A total of 2040 errors were deemed to have occurred to produce these failures. Planning error (19.7%), staff absence (16.2%), equipment unavailability (12.2%), communication error (11.2%), and lack of safety consciousness (6.1%) were the most frequent errors, accounting for 65.4% of the total. After intervention, 352 potential failures were recorded. Classification resulted in 477 errors. Preventable failures decreased from 54.6% to 27.3% (P < .001) with implementation of PPTR. Potential failure rates per hour decreased from 18.8 to 9.2 (P < .001), with no increase in potential to cause harm or procedural flow disruption per failure. Failures during VIR procedures are largely because of ineffective planning, communication error, and equipment difficulties, rather than a result of technical or patient-related issues. Many of these potential failures are preventable. A PPTR is an effective means of targeting frequent preventable failures, reducing procedural delays and improving patient safety.

Reliability of lead-calcium automotive batteries in practical operations

NASA Astrophysics Data System (ADS)

Burghoff, H.-G.; Richter, G.

In order to reach a statistically sound conclusion on the suitability of maintenance-free, lead-calcium automotive batteries for practical operations, the failure behaviour of such batteries has been observed in a large-scale experiment carried out by Mercedes Benz AG and Robert Bosch GmbH in different climatic zones of North America. The results show that the average failure behaviour is not significantly different to that of batteries from other manufacturers using other grid alloy systems and operated under otherwise identical conditions; the cumulative failure probability after 30 months is 17%. The principal causes of failure are: (i) early failure: transport damage, filling errors, and short-circuits due to the outer plates being pushed up during plate-block assembly (manufacturing defect); (ii) statistical failure: short-circuits due to growth of positive plates caused by a reduction in the mechanical strength of the cast positive grid as a result of corrosion; (iii) late failure due to an increased occurrence of short-circuits, especially frequent in outer cell facing the engine of the vehicle (subjected to high temperature), and to defects caused by capacity decay. As expected, the batteries exhibit extremely low water loss in each cell. The poor cyclical performance of stationary batteries, caused by acid stratification and well-known from laboratory tests, has no detrimental effect on the batteries in use. After a thorough analysis of the corrosion process, the battery manufacturer changed the grid alloy and the method of its production, and thus limited the corrosion problem with cast lead-calcium grids and with it the possibility of plate growth. The mathematical methods used in this study, and in particular the characteristic factors derived from them, have proven useful for assessing the suitability of automotive batteries.

Paralysis and heart failure precede ion balance disruption in heat-stressed European green crabs.

PubMed

Jørgensen, Lisa B; Overgaard, Johannes; MacMillan, Heath A

2017-08-01

Acute exposure of ectotherms to critically high temperatures causes injury and death, and this mortality has been associated with a number of physiological perturbations including impaired oxygen transport, loss of ion and water homeostasis, and neuronal failure. It is difficult to discern which of these factors, if any, is the proximate cause of heat injury because, for example, loss of ion homeostasis can impair neuromuscular function (including cardiac function), and conversely impaired oxygen transport reduces ATP supply and can thus reduce ion transport capacity. In this study we investigated if heat stress causes a loss of ion homeostasis in marine crabs and examined if such loss is related to heart failure. We held crabs (Carcinus maenas) at temperatures just below their critical thermal maximum and measured extracellular (hemolymph) and intracellular (muscle) ion concentrations over time. Analysis of Arrhenius plots for heart rates during heating ramps revealed a breakpoint temperature below which heart rate increased with temperature, and above which heart rate declined until complete cardiac failure. As hypothesised, heat stress reduced the Nernst equilibrium potentials of both K + and Na + , likely causing a depolarization of the membrane potential. To examine whether this loss of ion balance was likely to cause disruption of neuromuscular function, we exposed crabs to the same temperatures, but this time measured ion concentrations at the individual-specific times of complete paralysis (from which the crabs never recovered), and at the time of cardiac failure. Loss of ion balance was observed only after both paralysis and complete heart failure had occurred; indicating that the loss of neuromuscular function is not caused by a loss of ion homeostasis. Instead we suggest that the observed loss of ion balance may be linked to tissue damage related to heat death. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cerebellar medulloblastoma: the importance of posterior fossa dose to survival and patterns of failure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silverman, C.L.; Simpson, J.R.

1982-11-01

Fifty patients with biopsy-proven cerebellar medulloblastoma were retrospectively analyzed for prognostic factors, survival and patterns of failure. Five- and ten-year actuarial survivals for the entire group were 51% and 42%. Survival and local control were significantly better for the 21 patients who received doses greater than 5000 rad to the posterior fossa (85% and 80% respectively) than for the remaining patients (38% and 38%, respectively). Significant prognostic factors included achievement of local control in the posterior fossa (p = .0001) and dose to the posterior fossa (p = .0005). Sex, age, duration of symptoms, extent of surgery and initial T-stagemore » of disease were not significant. Posterior fossa was the predominant site of failure (71% of failures), but 10% of patients failed in the cerebrum and 12% outside the CNS. This experience confirms that survival rates of 70-80% are achievable with current treatment policies but accurate and consistent dose delivery to the posterior fossa is essential.« less

Cerebellar medulloblastoma: the importance of posterior fossa dose to survival and patterns of failure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silverman, C.L.; Simpson, J.R.

1982-11-01

Fifty patients with biopsy-proven cerebellar medulloblastoma were retrospectively analyzed for prognostic factors, survival and patterns of failure. Five- and ten-year actuarial survivals for the entire group were 51% and 42%. Survival and local control were significantly better for the 21 patients who received doses greater that 5000 rad to the posterior fossa (85% and 80% respectively) than for the remaining patients (38% and 38%, respectively). Significant prognostic factors included achievement of local control in the posterior fossa (p = .0001) and dose to the posterior fossa (p = .0005). Sex, age, duration of symptoms, extent of surgery and initial T-stagemore » of disease were not significant. Posterior fossa was the predominant site of failure (71% of failures), but 10% of patients failed in the cerebrum and 12% outside the CNS. This experience confirms that survival rates of 70-80% are achievable with current treatment policies but accurate and consistent dose delivery to the posterior fossa is essential.« less

Spoiled child syndrome.

PubMed

McIntosh, B J

1989-01-01

People often speak of children as being "spoiled" and many parents worry about the possibility of spoiling their infants and children. Many pediatricians, however, are uncomfortable with this term because it is a poorly defined and derogatory expression. Some would even deny that infants and children can be spoiled. Avoiding the use of the expression spoiled can create difficulties in communicating with parents concerned about their children's behavior. In this article, the spoiled child syndrome will be defined and those patterns of behavior that characterize it will be distinguished from other patterns of difficult behavior which may be confused with it. The spoiled child syndrome is characterized by excessive self-centered and immature behavior, resulting from the failure of parents to enforce consistent, age-appropriate limits. Many of the problem behaviors that cause parental concern are unrelated to spoiling as properly understood. Such behaviors are often age-related normal behaviors, reactions to family stresses, or patterns of behavior determined by factors inherent in the child. Pediatricians can provide counseling and reassurance for such behaviors and, by helping parents understand the etiology of true spoiling, can encourage the use of behavior modification techniques for its prevention and treatment.

Rheumatoid arthritis treatment with TNF inhibitors and alternative procedures in case of its failure – results of the Polish survey in the context of EULAR recommendations

PubMed Central

Dębowska, Grażyna; Spytek, Joanna; Tłustochowicz, Witold

2015-01-01

Introduction According to the European League Against Rheumatism (EULAR), rheumatoid arthritis (RA) treatment aims to achieve remission or low disease activity (LDA) within 6 months. In Poland, despite the existence of the National Health Fund Drug Program (NHF-DP), data on the effects of treatment with biological agents in patients with RA are not publicly available. Also we cannot compare registers from other countries with the Polish results because the rules of the therapeutic program in Poland impose restrictions that do not exist in other countries. For this reason, the data will not be comparable, but the results of the currently used regimen for biological treatment in Poland should be analyzed and compared with the recommendations of the European EULAR as a contribution to further discussion. Objectives To determine the tumor necrosis factor α (TNF-α) inhibitor treatment patterns in RA patients in Poland, to evaluate the frequency and causes of treatment failure as well as post-failure recommendations, and to compare Polish clinical practice enforced by the therapeutic program with the EULAR recommendations. Material and methods The data on 895 RA patients were retrospectively collected from routine medical records. A questionnaire was completed only once for each patient. Results After 3 months of treatment with a TNF-α inhibitor, the therapeutic target was achieved in 72% of patients: 4% in remission, 8% LDA, and 60% with moderate disease activity (MDA); after 9 months, 46% had reached the target: 16% in remission, 30% with LDA. An average of 49% of patients presented with MDA or high disease activity (HDA), thus requiring treatment modification. Treatment failure was confirmed in 14% of patients and a modified therapy administered: rituximab (72%) or adalimumab (20%). The most common cause of failure was inefficacy of treatment (70%). Conclusions In the Polish therapeutic program, despite the persistence of MDA or HDA, the treatment with TNF inhibitors rarely qualifies as ineffective and therefore is seldom modified by switching to another biologic drug. As long as the initiation of treatment and its modifications are enforced by the NHF-DP and not the recommendations of EULAR, treatment may be less effective and paradoxically cost-intensive. Therefore, it seems obvious that it is necessary to change and adapt the NHF-DP requirements to European standards. PMID:27407248

Evaluation of Effect of Zirconia Surface Treatment, Using Plasma of Argon and Silane, on the Shear Bond Strength of Two Composite Resin Cements

PubMed Central

Ramdev, Poojya; Shruthi, C S

2017-01-01

Introduction Yttria stabilised tetragonal zirconia opens new vistas for all ceramic restoration by the mechanism of transformation toughening, making it much stronger compared to all other ceramic materials. Currently, it is the most recent core material for all ceramic fixed partial dentures due to its ability to withstand high simulated masticatory loads. Problems which have been reported with zirconia restorations involve the core cement interface leading to loss of retention of the prosthesis. Different reasons which have been reported for the same include the lack of adhesion between zirconia and commonly used cements due to absence of silica phase which makes zirconia not etchable. In addition, the hydrophobic nature of zirconia causes low wettability of zirconia surface by the adhesive cements which are commonly used. Aim The purpose of this in vitro study was to compare and evaluate the effect of two pre-treatments of zirconia, using plasma of argon and silane, on the shear bond strength values of two composite resin cements to zirconia and to evaluate the failure pattern of the debonded areas using stereomicroscopic analysis. Materials and Methods Sixty zirconia discs (10 mm×2 mm) were randomly divided into three groups (n=20), following surface treatment, with airborne particle abrasion, using 110 µm Al2O3: Group I (control), Group II (plasma of argon cleaning), and Group III (application of silane primer). Each group had two subgroups based on the type of resin cement used for bonding: subgroup A; Rely X Ultimate (3M ESPE) and subgroup B; Panavia F (Kuraray). In subgroup A, Rely X universal silane primer and in subgroup B Clearfil ceramic primer was used. Shear bond strengths were determined after water storage for one day and thermocycling for 5000 cycles. Data (megapascal) were analyzed using ANOVA and Bonferroni test. Specimens were subjected to stereomicroscopic analysis, for evaluation of failure pattern. Results Group III produced the highest shear bond strength followed by Group II and Group I. Subgroup A showed higher shear bond strength than Subgroup B. Stereomicroscopic analysis showed cohesive failure in Group III, while in Group I adhesive failure was seen. Conclusion Silane primer application caused maximum increase in shear bond strength due to increased wettability. Argon plasma treatment was less effective in comparison to silane treatment. Air abrasion when used alone resulted in lower bond strength values, thereby making it necessary to use a combination of surface treatments. Rely X Ultimate cement was superior to Panavia F in terms of adhesive bonding to zirconia. PMID:28969271

Respiratory acidosis

MedlinePlus

Ventilatory failure; Respiratory failure; Acidosis - respiratory ... Causes of respiratory acidosis include: Diseases of the airways (such as asthma and COPD ) Diseases of the lung tissue (such as ...

Risk assessment for enterprise resource planning (ERP) system implementations: a fault tree analysis approach

NASA Astrophysics Data System (ADS)

Zeng, Yajun; Skibniewski, Miroslaw J.

2013-08-01

Enterprise resource planning (ERP) system implementations are often characterised with large capital outlay, long implementation duration, and high risk of failure. In order to avoid ERP implementation failure and realise the benefits of the system, sound risk management is the key. This paper proposes a probabilistic risk assessment approach for ERP system implementation projects based on fault tree analysis, which models the relationship between ERP system components and specific risk factors. Unlike traditional risk management approaches that have been mostly focused on meeting project budget and schedule objectives, the proposed approach intends to address the risks that may cause ERP system usage failure. The approach can be used to identify the root causes of ERP system implementation usage failure and quantify the impact of critical component failures or critical risk events in the implementation process.

Investigation of HP Turbine Blade Failure in a Military Turbofan Engine

NASA Astrophysics Data System (ADS)

Mishra, R. K.; Thomas, Johny; Srinivasan, K.; Nandi, Vaishakhi; Bhatt, R. Raghavendra

2017-04-01

Failure of a high pressure (HP) turbine blade in a military turbofan engine is investigated to determine the root cause of failure. Forensic and metallurgical investigations are carried out on the affected blades. The loss of coating and the presence of heavily oxidized intergranular fracture features including substrate material aging and airfoil curling in the trailing edge of a representative blade indicate that the coating is not providing adequate oxidation protection and the blade material substrate is not suitable for the application at hand. Coating spallation followed by substrate oxidation and aging leading to intergranular cracking and localized trailing edge curling is the root cause of the blade failure. The remaining portion of the blade fracture surface showed ductile overload features in the final failure. The damage observed in downstream components is due to secondary effects.

Prognostic value of 6-minute walk corridor test in patients with mild to moderate heart failure: comparison with other methods of functional evaluation.

PubMed

Rostagno, Carlo; Olivo, Giuseppe; Comeglio, Marco; Boddi, Vieri; Banchelli, Michela; Galanti, Giorgio; Gensini, Gian Franco

2003-06-01

The study was designed to evaluate the prognostic value of the 6-min walk test (6MWT) in patients with mild to moderate congestive heart failure (CHF). Two hundred and fourteen patients (119 men and 95 women, mean age 64 years) were followed for a mean period of 34 months to assess event-free survival (death, heart transplantation). Sixty-six patients (34%) died (63 cardiovascular causes, 2 cancer and 1 stroke) and five patients underwent heart transplantation. For patients who walked <300 m during the 6MWT, survival was 62% compared with 82% in patients who walked 300-450 m or>450 m. With univariate analysis, NYHA class was the strongest predictor of death. LVEF (P<0.0001), aetiology of heart failure (P<0.001), LV filling pattern (P=0.002) and 6MWT distance (P<0.01) were all significantly related to survival. No significant relationship was found between survival, peak oxygen consumption or anaerobic threshold. Multivariate analysis using the Cox-stepwise regression model showed that LV fractional shortening (P<0.009) and 6MWT distance (P<0.0005) were the strongest prognostic markers. A 6MWT distance of <300 m is a simple and useful prognostic marker of subsequent cardiac death in unselected patients with mild to moderate CHF.

The calibration of photographic and spectroscopic films. 1: Film batch variations of reciprocity failure in IIaO film. 2: Thermal and aging effects in relationship to reciprocity failure. 3: Shifting of reciprocity failure points as a function of thermal and aging effects

NASA Technical Reports Server (NTRS)

Peters, K. A.; Atkinson, P. F.; Hammond, E. C., Jr.

1986-01-01

Reciprocity failure was examined for IIaO spectroscopic film. Three separate experiments were performed in order to study film batch variations, thermal and aging effects in relationship to reciprocity failure, and shifting of reciprocity failure points as a function of thermal and aging effects. The failure was examined over ranges of time between 5 and 60 seconds. The variation to illuminance was obtained by using thirty neutral density filters. A standard sensitometer device imprinted the wedge pattern on the film as exposure time was subjected to variation. The results indicate that film batch differences, temperature, and aging play an important role in reciprocity failure of IIaO spectroscopic film. A shifting of the failure points was also observed in various batches of film.

Organizational Failure in an NHS Hospital Trust: A Qualitative Study.

PubMed

Ravaghi, Hamid; Mannion, Russell; Sajadi, Haniye Sadat

2015-01-01

The objective was to explore the key factors associated with organizational failure in an NHS Hospital Trust. This case study adopted a qualitative design. Fifty-seven semistructured interviews and document analyses were conducted as well. Data were analyzed using a framework analysis method. A range of symptoms of organizational performance failure was identified. These relate to a financial deficit, lack of good external relationships, inability to meet core targets, a lack of clear management systems, and low staff morale. These markers had not been taken seriously by the previous senior management team. Symptoms of failure were the reflection of presence of secondary and primary causes of failure. Poor managerial leadership, poor financial control and performance management, lack of open culture, distraction by 2 large projects, and the lack of clinician engagement were perceived as internal causes of failure and the high level of policy changes within the NHS as the key external cause. The level of deprivation in the area was also thought to have had a negative impact on performance. The findings reinforce and expand on those of recent studies across the public sector. Tracking an organization's performance and early diagnosis of performance problems, focusing on performance management systems, and taking into account contextual factors are issues that should be considered.

Sarcomere protein gene mutations and inherited heart disease: a beta-cardiac myosin heavy chain mutation causing endocardial fibroelastosis and heart failure.

PubMed

Kamisago, Mitsuhiro; Schmitt, Joachim P; McNamara, Dennis; Seidman, Christine; Seidman, J G

2006-01-01

Inherited human cardiomyopathies often lead to heart failure. A common feature of these conditions is that affected individuals can express the disease causing mutations for many years without showing clinical signs of the disease. Previous studies have demonstrated that sarcomere protein gene mutations can cause either dilated cardiomyopathy or hypertrophic cardiomyopathy. Here we demonstrate that the Arg442His missense mutation in beta-cardiac myosin heavy chain (betaMHC) causes dilated cardiomyopathy, endocardial fibroelastosis and heart failure at a very early age. Using standard genetic engineering tools we and others have made murine models by introducing human disease causing mutations into mice. The central hypothesis of these studies has been that by identifying the pathophysiological pathways activated by these mutations we can define enzymatic activities that are modified during the disease process and which may be involved in pathways that involve more common forms of cardiac disease. Murine models bearing different mutant myosins are being used to address whether each disease causing mutant betaMHC activates the same or different cellular pathways. Dissecting the molecular pathways modulated by mutations in sarcomere protein genes as well as other genes has already demonstrated that there are multiple pathways leading to cardiac remodelling and heart failure. Defining the mechanisms by which mutations in the same genes activate different cellular pathways remains an important question.

Pulmonary edema

MedlinePlus

... congestion; Lung water; Pulmonary congestion; Heart failure - pulmonary edema ... Pulmonary edema is often caused by congestive heart failure . When the heart is not able to pump efficiently, blood ...

Development, characterization, and modeling of ballistic impact on composite laminates under compressive pre-stress

NASA Astrophysics Data System (ADS)

Kerr-Anderson, Eric

Structural composite laminates were ballistically impacted while under in-plane compressive pre-stress. Residual properties, damage characterization, and energy absorption were compared to determine synergistic effects of in-plane compressive pre-stress and impact velocity. A fixture was developed to apply in-plane compressive loads up to 30 tons to structural composites during an impact event using a single-stage light-gas gun. Observed failure modes included typical conical delamination, the development of an impact initiated shear crack (IISC), and the shear failure of a pre-stressed composite due to impact. It was observed that the compressive failure threshold quadratically decreased in relation to the impact velocity up to velocities that caused partial penetration. For all laminates impacted at velocities causing partial or full penetration up to 350 ms-1, the failure threshold was consistent and used as an experimental normalization. Samples impacted below 65% of the failure threshold witnessed no significant change in damage morphology or residual properties when compared to typical conical delamination. Samples impacted above 65% of the failure threshold witnessed additional damage in the form of a shear crack extending perpendicular to the applied load from the point of impact. The presence of an IISC reduced the residual properties and even caused failure upon impact at extreme combinations. Four failure envelopes have been established as: transient failure, steady state failure, impact initiated shear crack, and conical damage. Boundaries and empirically based equations for residual compressive strength have been developed for each envelope with relation to two E-glass/vinyl ester laminate systems. Many aspects of pre-stressed impact have been individually examined, but there have been no comprehensive examinations of pre-stressed impact. This research has resulted in the exploration and characterization of compressively pre-stressed damage for impact velocities resulting in reflection, partial penetration, and penetration at pre-stress levels resulting in conical damage, shear cracking, and failure.

Probabilistic analysis on the failure of reactivity control for the PWR

NASA Astrophysics Data System (ADS)

Sony Tjahyani, D. T.; Deswandri; Sunaryo, G. R.

2018-02-01

The fundamental safety function of the power reactor is to control reactivity, to remove heat from the reactor, and to confine radioactive material. The safety analysis is used to ensure that each parameter is fulfilled during the design and is done by deterministic and probabilistic method. The analysis of reactivity control is important to be done because it will affect the other of fundamental safety functions. The purpose of this research is to determine the failure probability of the reactivity control and its failure contribution on a PWR design. The analysis is carried out by determining intermediate events, which cause the failure of reactivity control. Furthermore, the basic event is determined by deductive method using the fault tree analysis. The AP1000 is used as the object of research. The probability data of component failure or human error, which is used in the analysis, is collected from IAEA, Westinghouse, NRC and other published documents. The results show that there are six intermediate events, which can cause the failure of the reactivity control. These intermediate events are uncontrolled rod bank withdrawal at low power or full power, malfunction of boron dilution, misalignment of control rod withdrawal, malfunction of improper position of fuel assembly and ejection of control rod. The failure probability of reactivity control is 1.49E-03 per year. The causes of failures which are affected by human factor are boron dilution, misalignment of control rod withdrawal and malfunction of improper position for fuel assembly. Based on the assessment, it is concluded that the failure probability of reactivity control on the PWR is still within the IAEA criteria.

Enhancing the Possibility of Success by Measuring the Probability of Failure in an Educational Program.

ERIC Educational Resources Information Center

Brookhart, Susan M.; And Others

1997-01-01

Process Analysis is described as a method for identifying and measuring the probability of events that could cause the failure of a program, resulting in a cause-and-effect tree structure of events. The method is illustrated through the evaluation of a pilot instructional program at an elementary school. (SLD)

Radiation necrosis causing failure of automatic ventilation during sleep with central sleep apnea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Udwadia, Z.F.; Athale, S.; Misra, V.P.

A patient operated upon for a midline cerebellar hemangioblastoma developed failure of automatic respiration during sleep, together with central sleep apnea syndrome, approximately two years after receiving radiation therapy to the brain. Clinical and CT scan findings were compatible with a diagnosis of radiation necrosis as the cause of his abnormal respiratory control.

Business and the Press: Who's Doing What to Whom and Why?

ERIC Educational Resources Information Center

Taylor, Arthur R.

Among the causes of the recent breakdown of the business/press relationship is the increasing public and press questioning of business, coupled with the failure of business leaders to explain the benefits of the free enterprise system. This failure, caused largely by the direction of business leaders' energies inward toward their companies rather…

Qualitative Phenomenological Examination of IT Project Management in Pharmaceutical Industry

ERIC Educational Resources Information Center

Ly, Phil

2013-01-01

The purpose of this study was to examine what caused IT projects to fail at a high rate in the pharmaceutical industry. IT projects failures delayed development of new drugs that can help save lives. It was imperative to evaluate what caused project failures because the collateral damage was delay in drug development. This qualitative…

20 CFR 416.732 - No penalty deduction if you have good cause for failure to report timely.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false No penalty deduction if you have good cause for failure to report timely. 416.732 Section 416.732 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Reports Required Penalty Deductions...

20 CFR 416.732 - No penalty deduction if you have good cause for failure to report timely.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false No penalty deduction if you have good cause for failure to report timely. 416.732 Section 416.732 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Reports Required Penalty Deductions...

Congestive Heart Failure During Osimertinib Treatment for Epidermal Growth Factor Receptor (EGFR)-mutant Non-small Cell Lung Cancer (NSCLC).

PubMed

Watanabe, Hiromi; Ichihara, Eiki; Kano, Hirohisa; Ninomiya, Kiichiro; Tanimoto, Mitsune; Kiura, Katsuyuki

2017-08-15

We herein report a case of congestive heart failure which developed during osimertinib treatment. A 78-year-old woman presented with mild exertional dyspnea three weeks after starting osimertinib for the treatment of epidermal growth factor receptor (EGFR) T790M-positive non-small cell lung cancer. She was diagnosed with congestive heart failure caused by the osimertinib. In contrast to trastuzumab, a human epidermal growth factor receptor 2 (HER2) monoclonal antibody that often causes cardiac dysfunction, the causal relationship between osimertinib and cardiotoxicity has so far received little attention and thus remains unclear. However, it inhibits HER2 in addition to mutant EGFR, thereby potentially causing cardiotoxicity.

Questioning the Role of Requirements Engineering in the Causes of Safety-Critical Software Failures

NASA Technical Reports Server (NTRS)

Johnson, C. W.; Holloway, C. M.

2006-01-01

Many software failures stem from inadequate requirements engineering. This view has been supported both by detailed accident investigations and by a number of empirical studies; however, such investigations can be misleading. It is often difficult to distinguish between failures in requirements engineering and problems elsewhere in the software development lifecycle. Further pitfalls arise from the assumption that inadequate requirements engineering is a cause of all software related accidents for which the system fails to meet its requirements. This paper identifies some of the problems that have arisen from an undue focus on the role of requirements engineering in the causes of major accidents. The intention is to provoke further debate within the emerging field of forensic software engineering.

Congestive Heart Failure During Osimertinib Treatment for Epidermal Growth Factor Receptor (EGFR)-mutant Non-small Cell Lung Cancer (NSCLC)

PubMed Central

Watanabe, Hiromi; Ichihara, Eiki; Kano, Hirohisa; Ninomiya, Kiichiro; Tanimoto, Mitsune; Kiura, Katsuyuki

2017-01-01

We herein report a case of congestive heart failure which developed during osimertinib treatment. A 78-year-old woman presented with mild exertional dyspnea three weeks after starting osimertinib for the treatment of epidermal growth factor receptor (EGFR) T790M-positive non-small cell lung cancer. She was diagnosed with congestive heart failure caused by the osimertinib. In contrast to trastuzumab, a human epidermal growth factor receptor 2 (HER2) monoclonal antibody that often causes cardiac dysfunction, the causal relationship between osimertinib and cardiotoxicity has so far received little attention and thus remains unclear. However, it inhibits HER2 in addition to mutant EGFR, thereby potentially causing cardiotoxicity. PMID:28781309

[Case of Legionella pneumonia caused by a household humidifier].

PubMed

Endo, Keiichi; Ito, Kazuhisa

2009-05-01

A 60-year-old-man with diabetes mellitus was admitted to our hospital because of pyrexia of up to 40 degrees and dyspnea. Chest radiograph revealed ground glass infiltrates in both lung fields. Legionella pneumonia was diagnosed as a consequence of the urinary examination performed for Legionella antigen detection; further, we initiated intravenous pazufloxacin administration. Despite an antibiotic, sivelestat sodium, and mechanical ventilation, the condition of the patient worsened and he died of respiratory failure 5 days following admission. Pulse-field gel electrophoresis (PFGE) was performed to investigate the route of infection: this technique was applied to patient sputum samples and water from the humidifier in the room of the patient. The same DNA pattern as Legionella pneumophilla serogroup 1 was identified via analysis with PFGE.

Behavior treatment: general considerations.

PubMed

Gardner, William I

2005-01-01

The principal goal of behavior treatment for retarded clients is that of modifying behavior as it occurs in a given environment in such a manner that it becomes more appropriate to that environment. The therapeutic or change agents can involve a variety of persons other than the counselor, teacher, and client--this may include parents, peers, work supervisors and others who can provide supportive influences. Education and rehabilitation programs should be tailored to the occupational and social environment of the retarded client and designed to teach those behavior patterns that are relevant to that environment. Additionally, the work tasks for which retarded clients are trained should be highly structured and routine. Excessive demand for adaptability or decision making is a major cause of training failure for retarded clients.

Diversity is the question, not the answer

DOE PAGES

Shade, Ashley

2016-09-16

Local diversity (within-sample or alpha diversity) is often implicated as a cause of success or failure of a microbial community. However, the relationships between diversity and emergent properties of a community, such as its stability, productivity or invasibility, are much more nuanced. In this paper, I argue that diversity without context provides limited insights into the mechanisms underpinning community patterns. I provide examples from traditional and microbial ecology to discuss common complications and assumptions about within-sample diversity that may prevent us from digging deeper into the more specific mechanisms underpinning community outcomes. I suggest that measurement of diversity should servemore » as a starting point for further inquiry of ecological mechanisms rather than an 'answer' to community outcomes.« less

Readmission after pancreatic resection: causes and causality pattern.

PubMed

Sadot, Eran; Brennan, Murray F; Lee, Ser Yee; Allen, Peter J; Gönen, Mithat; Groeger, Jeffery S; Peter Kingham, T; D'Angelica, Michael I; DeMatteo, Ronald P; Jarnagin, William R; Fong, Yuman

2014-12-01

Readmission rates have been targeted for cost/reimbursement control. Our goal was to identify causes for readmission and delineate the pattern of early and late readmission. Between 2011 and 2012, a total of 490 patients underwent pancreaticoduodenectomy, distal pancreatectomy or central pancreatectomy. Logistic regression was used to identify predictors of readmission. K-medoids clustering was performed to identify the major readmission subgroups. Median postoperative length of stay (LOS) was 7 days, and the 30- and 90-day readmission rates were 23 and 29 %, respectively. The most common cause for 30-day readmissions was procedure-related infections (58 %), while the most common cause for 31-90-day readmissions was failure to thrive and chemotherapy-related symptoms (38 %). Independent predictors of 30-day readmissions were central pancreatectomy, discharge with a drain, pancreatic duct <3 mm, previous abdominal surgery, and postoperative LOS. Independent predictors for 31-90-day readmissions were age and preoperative serum carcinoembryonic antigen. Cancer-related covariates were more common in the 31-90-day readmission group. Postoperative carbohydrate antigen 19-9 levels were twofold higher in the 31-90-day readmission group compared with the no readmission group (p = 0.03). K-medoids clustering identified a subgroup where 74 % of readmissions occur at a median of 7 days after discharge. Readmissions after pancreatic operations are procedure-related in the first 30 days, but those after this period are influenced by the natural history of the underlying diagnosis. The readmission penalty policy should account for the timing of readmission and the natural history of the underlying disease and procedure. Early follow-up for patients at high risk for readmission may minimize early readmissions.

Variation in Postsepsis Readmission Patterns: A Cohort Study of Veterans Affairs Beneficiaries.

PubMed

Prescott, Hallie C

2017-02-01

Rehospitalization is common after sepsis, but little is known about the variation in readmission patterns across patient groups and care locations. To examine the variation in postsepsis readmission rates and diagnoses by patient age, nursing facility use, admission year, and hospital among U.S. Veterans Affairs (VA) beneficiaries. Observational cohort study of VA beneficiaries who survived a sepsis hospitalization (2009-2011) at 114 VA hospitals, stratified by age (<65 vs. ≥65 yr), nursing home usage (none, chronic, or acute), year of admission (2009, 2010, 2011), and hospital. In the primary analysis, sepsis hospitalizations were identified using a previously validated method. Sensitivity analyses were performed using alternative definitions with explicit International Classification of Diseases, Ninth Revision, Clinical Modification, codes for sepsis, and separately for severe sepsis and septic shock. The primary outcomes were rate of 90-day all-cause hospital readmission after sepsis hospitalization and proportion of readmissions resulting from specific diagnoses, including the proportion of "potentially preventable" readmissions. Readmission diagnoses were similar from 2009 to 2011, with little variation in readmission rates across hospitals. The top six readmission diagnoses (heart failure, pneumonia, sepsis, urinary tract infection, acute renal failure, and chronic obstructive pulmonary disease) accounted for 30% of all readmissions. Although about one in five readmissions had a principal diagnosis for infection, 58% of all readmissions received early systemic antibiotics. Infection accounted for a greater proportion of readmissions among patients discharged to nursing facilities compared with patients discharged to home (25.0-27.1% vs. 16.8%) and among older vs. younger patients (22.2% vs. 15.8%). Potentially preventable readmissions accounted for a quarter of readmissions overall and were more common among older patients and patients discharged to nursing facilities. Hospital readmission rates after sepsis were similar by site and admission year. Heart failure, pneumonia, sepsis, and urinary tract infection were common readmission diagnoses across all patient groups. Readmission for infection and potentially preventable diagnoses were more common in older patients and patients discharged to nursing facilities.

Electrophysiological diagnosis and patterns of response to treatment of botulism with neuromuscular respiratory failure.

PubMed

Kongsaengdao, Subsai; Samintarapanya, Kanoksri; Rusmeechan, Siwarit; Sithinamsuwan, Pasiri; Tanprawate, Surat

2009-08-01

In this study we describe the electrophysiological findings in botulism patients with neuromuscular respiratory failure from major botulism outbreaks in Thailand. High-rate repetitive nerve stimulation testing (RNST) of the abductor digiti minimi (ADM) muscle of 17 botulism patients with neuromuscular respiratory failure showed mostly incremental responses, especially in response to >20-HZ stimulation. In the most severe stage of neuromuscular respiratory failure, RNST failed to elicit a compound muscle action potential (CMAP) of the ADM muscle. In the moderately severe stage, the initial CMAPs were of very low amplitude, and a 3-HZ RNST elicited incremental or decremental responses. A 10-HZ RNST elicited mainly decremental responses. In the early recovery stage, the initial CMAP amplitudes of the ADM muscle improved, with initially low amplitudes and an incremental response to 3- and 10-HZ RNSTs. Improved electrophysiological patterns of the ADM muscle correlated with improved respiratory muscle function. Incremental responses to 20-HZ RNST were most useful for diagnosis. The initial electrodiagnostic sign of recovery following treatment of neuromuscular respiratory failure was an increased CMAP amplitude and an incremental response to 10-20-HZ RNST. Muscle Nerve 40: 271-278, 2009.

Congenital proprotein convertase 1/3 deficiency causes malabsorptive diarrhea and other endocrinopathies in a pediatric cohort.

PubMed

Martín, Martín G; Lindberg, Iris; Solorzano-Vargas, R Sergio; Wang, Jiafang; Avitzur, Yaron; Bandsma, Robert; Sokollik, Christiane; Lawrence, Sarah; Pickett, Lindsay A; Chen, Zijun; Egritas, Odul; Dalgic, Buket; Albornoz, Valeria; de Ridder, Lissy; Hulst, Jessie; Gok, Faysal; Aydoğan, Ayşen; Al-Hussaini, Abdulrahman; Gok, Deniz Engin; Yourshaw, Michael; Wu, S Vincent; Cortina, Galen; Stanford, Sara; Georgia, Senta

2013-07-01

Proprotein convertase 1/3 (PC1/3) deficiency, an autosomal-recessive disorder caused by rare mutations in the proprotein convertase subtilisin/kexin type 1 (PCSK1) gene, has been associated with obesity, severe malabsorptive diarrhea, and certain endocrine abnormalities. Common variants in PCSK1 also have been associated with obesity in heterozygotes in several population-based studies. PC1/3 is an endoprotease that processes many prohormones expressed in endocrine and neuronal cells. We investigated clinical and molecular features of PC1/3 deficiency. We studied the clinical features of 13 children with PC1/3 deficiency and performed sequence analysis of PCSK1. We measured enzymatic activity of recombinant PC1/3 proteins. We identified a pattern of endocrinopathies that develop in an age-dependent manner. Eight of the mutations had severe biochemical consequences in vitro. Neonates had severe malabsorptive diarrhea and failure to thrive, required prolonged parenteral nutrition support, and had high mortality. Additional endocrine abnormalities developed as the disease progressed, including diabetes insipidus, growth hormone deficiency, primary hypogonadism, adrenal insufficiency, and hypothyroidism. We identified growth hormone deficiency, central diabetes insipidus, and male hypogonadism as new features of PCSK1 insufficiency. Interestingly, despite early growth abnormalities, moderate obesity, associated with severe polyphagia, generally appears. In a study of 13 children with PC1/3 deficiency caused by disruption of PCSK1, failure of enteroendocrine cells to produce functional hormones resulted in generalized malabsorption. These findings indicate that PC1/3 is involved in the processing of one or more enteric hormones that are required for nutrient absorption. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

Gut microbial translocation corrupts myeloid cell function to control bacterial infection during liver cirrhosis.

PubMed

Hackstein, Carl-Philipp; Assmus, Lisa Mareike; Welz, Meike; Klein, Sabine; Schwandt, Timo; Schultze, Joachim; Förster, Irmgard; Gondorf, Fabian; Beyer, Marc; Kroy, Daniela; Kurts, Christian; Trebicka, Jonel; Kastenmüller, Wolfgang; Knolle, Percy A; Abdullah, Zeinab

2017-03-01

Patients with liver cirrhosis suffer from increased susceptibility to life-threatening bacterial infections that cause substantial morbidity. Experimental liver fibrosis in mice induced by bile duct ligation or CCl 4 application was used to characterise the mechanisms determining failure of innate immunity to control bacterial infections. In murine liver fibrosis, translocation of gut microbiota induced tonic type I interferon (IFN) expression in the liver. Such tonic IFN expression conditioned liver myeloid cells to produce high concentrations of IFN upon intracellular infection with Listeria that activate cytosolic pattern recognition receptors. Such IFN-receptor signalling caused myeloid cell interleukin (IL)-10 production that corrupted antibacterial immunity, leading to loss of infection-control and to infection-associated mortality. In patients with liver cirrhosis, we also found a prominent liver IFN signature and myeloid cells showed increased IL-10 production after bacterial infection. Thus, myeloid cells are both source and target of IFN-induced and IL-10-mediated immune dysfunction. Antibody-mediated blockade of IFN-receptor or IL-10-receptor signalling reconstituted antibacterial immunity and prevented infection-associated mortality in mice with liver fibrosis. In severe liver fibrosis and cirrhosis, failure to control bacterial infection is caused by augmented IFN and IL-10 expression that incapacitates antibacterial immunity of myeloid cells. Targeted interference with the immune regulatory host factors IL-10 and IFN reconstitutes antibacterial immunity and may be used as therapeutic strategy to control bacterial infections in patients with liver cirrhosis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Clinical Courses of Graft Failure Caused by Chronic Allograft Dysfunction in Kidney Transplantation.

PubMed

Fujiwara, T; Teruta, S; Tsudaka, S; Ota, K; Matsuda, H

Chronic allograft dysfunction (CAD) is a main cause of graft failure in kidney transplantation. We retrospectively analyzed 279 kidney transplant recipients who survived with a functioning graft for at least 2 years. CAD was defined as chronic graft deterioration, excluding other specific causes. We defined the pattern of decline in estimated glomerular filtration rate (eGFR), as follows: (1) "plateau" was defined as decline in eGFR ≤2 mL/min/1.73 m 2 /year; "long plateaus" were those lasting more than 5 years; (2) "rapid decline" was a decrease in eGFR ≥20 mL/min/1.73 m 2 /year. Patients diagnosed with CAD were categorized according to the occurrence of rapid decline and/or long plateau as follows: group 1, neither rapid decline nor long plateau; group 2, rapid decline only; group 3, long plateau only; and group 4, both rapid decline and long plateau. From a total of 81 graft losses, 51 (63%) failed because of CAD, with a median of 9.4 years. Sixteen patients belonged to group 1, 14 to group 2, 12 to group 3, and nine to group 4. Mean graft survival times in the four groups were 7.7 ± 1.1, 6.1 ± 3.1, 16.2 ± 2.5, and 10.8 ± 3.6 years, respectively (P < .001). There were significant differences among groups in donor age, year of transplantation, mean eGFR at baseline, and acute rejection rate after transplantation. The results indicate that this cohort of kidney transplant recipients who had CAD comprised subgroups with different clinical courses. Copyright © 2016 Elsevier Inc. All rights reserved.

Pyrotechnic system failures: Causes and prevention

NASA Technical Reports Server (NTRS)

Bement, Laurence J.

1988-01-01

Although pyrotechnics have successfully accomplished many critical mechanical spacecraft functions, such as ignition, severance, jettisoning and valving (excluding propulsion), failures continue to occur. Provided is a listing of 84 failures of pyrotechnic hardware with completed design over a 23-year period, compiled informally by experts from every NASA Center, as well as the Air Force Space Division and the Naval Surface Warfare Center. Analyses are presented as to when and where these failures occurred, their technical source or cause, followed by the reasons why and how these kinds of failures persist. The major contributor is a fundamental lack of understanding of the functional mechanisms of pyrotechnic devices and systems, followed by not recognizing pyrotechnics as an engineering technology, insufficient manpower with hands-on experience, too few test facilities, and inadequate guidelines and specifications for design, development, qualification and acceptance. Recommendations are made on both a managerial and technical basis to prevent failures, increase reliability, improve existing and future designs, and develop the technology to meet future requirements.

Facilitation of Learning of a Simultaneous Discrimination between Rotated Patterns by Bumblebees

ERIC Educational Resources Information Center

Perreault, M. J.; Plowright, C. M. S.

2009-01-01

The failure to discriminate between a pattern consisting of four orthogonal bars and the same pattern rotated by 45 degrees has been interpreted in the literature as evidence against pictorial representations in honeybees. This study determines whether prior training can facilitate the discrimination. In Experiment 1, one group of bumblebees was…

Sleep and wake phase of heart beat dynamics by artificial insymmetrised patterns

NASA Astrophysics Data System (ADS)

Dudkowska, A.; Makowiec, D.

2004-05-01

In order to determine differences between healthy patients and patients with congestive heart failure we apply the artificial insymmetrised pattern (AIP) method. The AIP method by exploring a human eye ability to extract regularities and read symmetries in a dot pattern, serves a tool for qualitative discrimination of heart rate states.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, K.A.; Atkinson, P.F.; Hammond, E.C.,JR.

Reciprocity failure was examined for IIaO spectroscopic film. Three separate experiments were performed in order to study film batch variations, thermal and aging effects in relationship to reciprocity failure, and shifting of reciprocity failure points as a function of thermal and aging effects. The failure was examined over ranges of time between 5 and 60 seconds. The variation to illuminance was obtained by using thirty neutral density filters. A standard sensitometer device imprinted the wedge pattern on the film as exposure time was subjected to variation. The results indicate that film batch differences, temperature, and aging play an important rolemore » in reciprocity failure of IIaO spectroscopic film. A shifting of the failure points was also observed in various batches of film.« less

Determination of a tissue-level failure evaluation standard for rat femoral cortical bone utilizing a hybrid computational-experimental method.

PubMed

Fan, Ruoxun; Liu, Jie; Jia, Zhengbin; Deng, Ying; Liu, Jun

2018-01-01

Macro-level failure in bone structure could be diagnosed by pain or physical examination. However, diagnosing tissue-level failure in a timely manner is challenging due to the difficulty in observing the interior mechanical environment of bone tissue. Because most fractures begin with tissue-level failure in bone tissue caused by continually applied loading, people attempt to monitor the tissue-level failure of bone and provide corresponding measures to prevent fracture. Many tissue-level mechanical parameters of bone could be predicted or measured; however, the value of the parameter may vary among different specimens belonging to a kind of bone structure even at the same age and anatomical site. These variations cause difficulty in representing tissue-level bone failure. Therefore, determining an appropriate tissue-level failure evaluation standard is necessary to represent tissue-level bone failure. In this study, the yield and failure processes of rat femoral cortical bones were primarily simulated through a hybrid computational-experimental method. Subsequently, the tissue-level strains and the ratio between tissue-level failure and yield strains in cortical bones were predicted. The results indicated that certain differences existed in tissue-level strains; however, slight variations in the ratio were observed among different cortical bones. Therefore, the ratio between tissue-level failure and yield strains for a kind of bone structure could be determined. This ratio may then be regarded as an appropriate tissue-level failure evaluation standard to represent the mechanical status of bone tissue.

Firework injuries: a ten-year study.

PubMed

Puri, Vinita; Mahendru, Sanjay; Rana, Roshani; Deshpande, Manish

2009-09-01

Fireworks are used worldwide to celebrate popular events (e.g. festivals, official celebrations, weddings). The festival of lights (Diwali) is celebrated with fireworks in India. During this period, many patients from all age groups present to hospital with injuries due to fireworks. Prevalence, period of occurrence, sex and age variation, adult supervision, causative fireworks, mode of lighting, age groups prone to injury, patterns of injury caused by individual fireworks, and the body parts injured were studied. One hundred and fifty-seven cases (92 retrospective, 65 prospective) with injury due to fireworks presenting to the Department of Plastic Surgery at KEM Hospital between 1997 and 2006 were studied. The prevalence of injuries has decreased steadily over the last 10 years (41 cases in 1997, 3 cases in 2006). The maximum number of injuries (35%) was seen in the age group 5-14 years; 92% of these children were unsupervised. The commonest cause of injury was firework misuse (41% of cases), followed by device failure (35%). Device failure was commonest with flares/fountains (ground firework emitting sparks upwards) and aerial devices. Flare/fountains caused most injury (39%), sparklers the least (0.6%). Flare/fountains, ground spinners, sparklers, and gunpowder (explosive material from cracker, obtained by tearing paper wrapper and obtaining chemicals) caused only soft tissue burns; stringbombs (high-intensity fire cracker made by wrapping chemicals with jute strings/coir in layers) and rockets (aerial device that zooms upwards and bursts) caused blast injuries, leading to soft tissue disruption and bony injuries. Emergency surgery was done if indicated: tendon and/or neurovascular repair, fracture fixation, flap cover or amputation. Superficial burns were treated with dressings. Certain wounds needed only thorough cleansing of the wound and primary suturing. We concluded that, over a 10-year period, the prevalence of firework injury decreased due to increased awareness in the community. Aggressive awareness campaigns by government and non-government organisations was the cause. We can minimise the number and severity of accidents by raising awareness regarding safety precautions, encouraging professional displays and motivating manufacturers to adhere to strict quality control.

Quasi-static and dynamic experimental studies on the tensile strength and failure pattern of concrete and mortar discs.

PubMed

Jin, Xiaochao; Hou, Cheng; Fan, Xueling; Lu, Chunsheng; Yang, Huawei; Shu, Xuefeng; Wang, Zhihua

2017-11-10

As concrete and mortar materials widely used in structural engineering may suffer dynamic loadings, studies on their mechanical properties under different strain rates are of great importance. In this paper, based on splitting tests of Brazilian discs, the tensile strength and failure pattern of concrete and mortar were investigated under quasi-static and dynamic loadings with a strain rate of 1-200 s -1 . It is shown that the quasi-static tensile strength of mortar is higher than that of concrete since coarse aggregates weaken the interface bonding strength of the latter. Numerical results confirmed that the plane stress hypothesis lead to a lower value tensile strength for the cylindrical specimens. With the increase of strain rates, dynamic tensile strengths of concrete and mortar significantly increase, and their failure patterns change form a single crack to multiple cracks and even fragment. Furthermore, a relationship between the dynamic increase factor and strain rate was established by using a linear fitting algorithm, which can be conveniently used to calculate the dynamic increase factor of concrete-like materials in engineering applications.

Ventricular septal defect

MedlinePlus

... causing an irregular or slow heart rhythm) Delayed growth and development ( failure to thrive in infancy) Heart failure Infective endocarditis (bacterial infection of the heart) Pulmonary hypertension (high blood ...

Ebolavirus and Haemorrhagic Syndrome

PubMed Central

Matua, Gerald A.; Van der Wal, Dirk M.; Locsin, Rozzano C.

2015-01-01

The Ebola virus is a highly virulent, single-stranded ribonucleic acid virus which affects both humans and apes and has fast become one of the world’s most feared pathogens. The virus induces acute fever and death, with haemorrhagic syndrome occurring in up to 90% of patients. The known species within the genus Ebolavirus are Bundibugyo, Sudan, Zaïre, Reston and Taï Forest. Although endemic in Africa, Ebola has caused worldwide anxiety due to media hype and concerns about its international spread, including through bioterrorism. The high fatality rate is attributed to unavailability of a standard treatment regimen or vaccine. The disease is frightening since it is characterised by rapid immune suppression and systemic inflammatory response, causing multi-organ and system failure, shock and often death. Currently, disease management is largely supportive, with containment efforts geared towards mitigating the spread of the virus. This review describes the classification, morphology, infective process, natural ecology, transmission, epidemic patterns, diagnosis, clinical features and immunology of Ebola, including management and epidemic containment strategies. PMID:26052448

Ebolavirus and Haemorrhagic Syndrome.

PubMed

Matua, Gerald A; Van der Wal, Dirk M; Locsin, Rozzano C

2015-05-01

The Ebola virus is a highly virulent, single-stranded ribonucleic acid virus which affects both humans and apes and has fast become one of the world's most feared pathogens. The virus induces acute fever and death, with haemorrhagic syndrome occurring in up to 90% of patients. The known species within the genus Ebolavirus are Bundibugyo, Sudan, Zaïre, Reston and Taï Forest. Although endemic in Africa, Ebola has caused worldwide anxiety due to media hype and concerns about its international spread, including through bioterrorism. The high fatality rate is attributed to unavailability of a standard treatment regimen or vaccine. The disease is frightening since it is characterised by rapid immune suppression and systemic inflammatory response, causing multi-organ and system failure, shock and often death. Currently, disease management is largely supportive, with containment efforts geared towards mitigating the spread of the virus. This review describes the classification, morphology, infective process, natural ecology, transmission, epidemic patterns, diagnosis, clinical features and immunology of Ebola, including management and epidemic containment strategies.

Two Hundred Thirty-Six Children With Developmental Hydrocephalus: Causes and Clinical Consequences.

PubMed

Tully, Hannah M; Ishak, Gisele E; Rue, Tessa C; Dempsey, Jennifer C; Browd, Samuel R; Millen, Kathleen J; Doherty, Dan; Dobyns, William B

2016-03-01

Few systematic assessments of developmental forms of hydrocephalus exist. We reviewed magnetic resonance images (MRIs) and clinical records of patients with infancy-onset hydrocephalus. Among 411 infants, 236 had hydrocephalus with no recognizable extrinsic cause. These children were assigned to 1 of 5 subtypes and compared on the basis of clinical characteristics and developmental and surgical outcomes. At an average age of 5.3 years, 72% of children were walking independently and 87% could eat by mouth; in addition, 18% had epilepsy. Distinct patterns of associated malformations and syndromes were observed within each subtype. On average, children with aqueductal obstruction, cysts, and encephaloceles had worse clinical outcomes than those with other forms of developmental hydrocephalus. Overall, 53% of surgically treated patients experienced at least 1 shunt failure, but hydrocephalus associated with posterior fossa crowding required fewer shunt revisions. We conclude that each subtype of developmental hydrocephalus is associated with distinct clinical characteristics, syndromology, and outcomes, suggesting differences in underlying mechanisms. © The Author(s) 2015.

Hippi is essential for node cilia assembly and Sonic hedgehog signaling

PubMed Central

Houde, Caroline; Dickinson, Robin J.; Houtzager, Vicky M.; Cullum, Rebecca; Montpetit, Rachel; Metzler, Martina; Simpson, Elizabeth M.; Roy, Sophie; Hayden, Michael R.; Hoodless, Pamela A.; Nicholson, Donald W.

2016-01-01

Hippi functions as an adapter protein that mediates pro-apoptotic signaling from poly-glutamine-expanded huntingtin, an established cause of Huntington disease, to the extrinsic cell death pathway. To explore other functions of Hippi we generated Hippi knock-out mice. This deletion causes randomization of the embryo turning process and heart looping, which are hallmarks of defective left–right (LR) axis patterning. We report that motile monocilia normally present at the surface of the embryonic node, and proposed to initiate the break in LR symmetry, are absent on Hippi−/− embryos. Furthermore, defects in central nervous system development are observed. The Sonic hedgehog (Shh) pathway is downregulated in the neural tube in the absence of Hippi, which results in failure to establish ventral neural cell fate. Together, these findings demonstrate a dual role for Hippi in cilia assembly and Shh signaling during development, in addition to its proposed role in apoptosis signal transduction in the adult brain under pathogenically stressful conditions. PMID:17027958

Ferrographic and spectrometer oil analysis from a failed gas turbine engine

NASA Technical Reports Server (NTRS)

Jones, W. R., Jr.

1983-01-01

An experimental gas turbine engine was destroyed as a result of the combustion of its titanium components. It was concluded that a severe surge may have caused interference between rotating and stationary compressor parts that either directly or indirectly ignited the titanium components. Several engine oil samples (before and after the failure) were analyzed with a Ferrograph, and with plasma, atomic absorption, and emission spectrometers to see if this information would aid in the engine failure diagnosis. The analyses indicated that a lubrication system failure was not a causative factor in the engine failure. Neither an abnormal wear mechanism nor a high level of wear debris was detected in the engine oil sample taken just prior to the test in which the failure occurred. However, low concentrations (0.2 to 0.5 ppm) of titanium were evident in this sample and samples taken earlier. After the failure, higher titanium concentrations (2 ppm) were detected in oil samples taken from different engine locations. Ferrographic analysis indicated that most of the titanium was contained in spherical metallic debris after the failure. The oil analyses eliminated a lubrication system bearing or shaft seal failure as the cause of the engine failure. Previously announced in STAR as N83-12433

Pilot error in air carrier accidents: does age matter?

PubMed

Li, Guohua; Grabowski, Jurek G; Baker, Susan P; Rebok, George W

2006-07-01

The relationship between pilot age and safety performance has been the subject of research and controversy since the "Age 60 Rule" became effective in 1960. This study aimed to examine age-related differences in the prevalence and patterns of pilot error in air carrier accidents. Investigation reports from the National Transportation Safety Board for accidents involving Part 121 operations in the United States between 1983 and 2002 were reviewed to identify pilot error and other contributing factors. Accident circumstances and the presence and type of pilot error were analyzed in relation to pilot age using Chi-square tests. Of the 558 air carrier accidents studied, 25% resulted from turbulence, 21% from mechanical failure, 16% from taxiing events, 13% from loss of control at landing or takeoff, and 25% from other causes. Accidents involving older pilots were more likely to be caused by turbulence, whereas accidents involving younger pilots were more likely to be taxiing events. Pilot error was a contributing factor in 34%, 38%, 35%, and 34% of the accidents involving pilots ages 25-34 yr, 35-44 yr, 45-54 yr, and 55-59 yr, respectively (p = 0.87). The patterns of pilot error were similar across age groups. Overall, 26% of the pilot errors identified were inattentiveness, 22% flawed decisions, 22% mishandled aircraft kinetics, and 11% poor crew interactions. The prevalence and patterns of pilot error in air carrier accidents do not seem to change with pilot age. The lack of association between pilot age and error may be due to the "safe worker effect" resulting from the rigorous selection processes and certification standards for professional pilots.

[Acute renal failure due to obstructive ureteral stone associated with norovirus gastroenteritis in an infant with congenital solitary kidney].

PubMed

Kato, Taiki; Hamano, Atsushi; Kawamura, Hideki

2014-10-01

We report a 35 month-old boy with acute renal failure caused by an obstructive ureteral stone associated with norovirus gastroenteritis. He visited his family physician because of fever, abdominal pain and vomiting. He was diagnosed as acute gastroenteritis. The symptoms relieved once, but abdominal pain and vomiting recurred two days after the visit and the volume of urine decreased. He was diagnosed as norovirus gastoenteritis and acute renal failure which was unresponsive to fluid replacement. Ultrasound study of the abdomen showed a solitary kidney with mild hydronephrosis. He was then admitted to our hospital. He was finally diagnosed as acute postrenal failure due to obstructive ureteral stone with left solitary kidney by abdominal computer tomography (CT). We performed transurethral catheterization immediately. The creatinine and blood urea nitrogen returned to normal level in 2 days. The CT performed on the 28th day post operation showed disappearance of the stone after uric alkalization. Recently, some cases of postrenal failure due to bilateral obstructive ureteral stones, mainly ammonium acid urate stones, associated with viral gastroenteritis were reported. As clinical features, they are common in boys three years or younger after an episode of rotavirus gastroenteritis with high uric acid concentration. By far, the most common cause of acute renal failure in patients with severe gastroenteritis is prerenal failure resulting from hypovolemia. But postrenal cause due to bilateral obstructive stones should be taken in a consideration.

Attributions of Female and Male Adolescents for Real-Life Failure Experiences.

ERIC Educational Resources Information Center

Farmer, Helen S.; Vispoel, Walter P.

1990-01-01

A study involving 697 male and 765 female ninth and twelfth graders was undertaken to assess learned helplessness in attribution patterns associated with personal failure. Although significant gender differences were identified, little evidence was obtained supporting the learned helplessness model for adolescent female achievement motivation.…

Patterns of Failure After Concurrent Bevacizumab and Hypofractionated Stereotactic Radiation Therapy for Recurrent High-Grade Glioma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shapiro, Lauren Q.; Beal, Kathryn, E-mail: bealk@mskcc.org; Goenka, Anuj

2013-03-01

Purpose: Concurrent bevacizumab with hypofractionated stereotactic radiation therapy (HSRT) is safe and effective for the treatment of recurrent high-grade gliomas (HGG). The objective of this study was to characterize the patterns of failure after this treatment regimen. Methods and Materials: Twenty-four patients with recurrent enhancing HGG were previously treated on an institutional review board-approved protocol of concurrent bevacizumab and reirradiation. Patients received 30 Gy in 5 fractions to the recurrent tumor with HSRT. Brain magnetic resonance imaging (MRI) was performed every 2 cycles, and bevacizumab was continued until clinical or radiographic tumor progression according to the criteria of Macdonald etmore » al. MRI at the time of progression was fused to the HSRT treatment plan, and the location of recurrence was classified on the basis of volume within the 95% isodose line. Outcomes based on patient characteristics, tumor grade, recurrence pattern, and best response to treatment were analyzed by the Kaplan-Meier method. Results: Twenty-two patients experienced either clinical or radiographic progression. Recurrent tumor was enhancing in 15 (71.4%) and nonenhancing in 6 (28.6%) patients. Eleven patients (52.4%) had recurrence within the radiation field, 5 patients (23.8%) had marginal recurrence, and 5 patients had recurrence outside the radiation field. Pattern of enhancement and location of failure did not correlate with overall survival or progression-free survival. Radiographic response was the only variable to significantly correlate with progression-free survival. Conclusions: Despite the promising initial response seen with the addition of HSRT to bevacizumab as salvage treatment for recurrent HGG, approximately half of patients ultimately still experience failure within the radiation field. The rate of local failure with the addition of HSRT seems to be lower than that seen with bevacizumab alone in the salvage setting. Our data underscore the radioresistance of HGG and the need for better salvage treatments.« less

Transverse Isotropy of Phyllite Under Brazilian Tests: Laboratory Testing and Numerical Simulations

NASA Astrophysics Data System (ADS)

Xu, Guowen; He, Chuan; Chen, Ziquan; Su, Ang

2018-04-01

Phyllite is a low-grade, metamorphic rock with well-developed foliation. We characterized the fracture pattern and failure strength of phyllite specimens under Brazilian tests. The specimens were obtained from the Zhegu mountain tunnel in China and had different foliation-loading angles, namely 0°, 15°, 30°, 45°, 60°, 75° and 90°. The processes for the initiation and propagation of macro-cracks were recorded using high-speed photography. The evolution of micro-cracks was analyzed based on the results of acoustic emission (AE) tests. The failure process of the specimens during the Brazilian tests was simulated with a new numerical approach based on the particle discrete element method. The influence of foliation strength and the microstructure of the rock matrix were also studied numerically. The experimental results showed that the failure strength of the specimens was related to their fracture patterns and the areas of their fracture surfaces. The initial cracking point of the specimens appeared at the upper or lower loading position, and the cracks propagated to the boundaries of the specimens along or across foliation. The temporal distributions of the AE counts and AE energy of the specimens were affected predominantly by the fracture pattern, and we divided these distributions into two modes: the peak mode and the uniformly distributed mode. The numerical results indicated that the fracture surface was roughly parallel to the loading direction and that the surface was located in the central part of the disk specimens for rocks with loose structure (low coordination number or large crack density) or with strong foliation, i.e., foliation with high shear strength. The failure pattern and trends of variation in failure strength as a function of foliation-loading angles varied with the ratio of cohesion to the tensile strength of foliation, the crack density, and the coordination number.

The use of subjective expert opinions in cost optimum design of aerospace structures. [probabilistic failure models

NASA Technical Reports Server (NTRS)

Thomas, J. M.; Hanagud, S.

1975-01-01

The results of two questionnaires sent to engineering experts are statistically analyzed and compared with objective data from Saturn V design and testing. Engineers were asked how likely it was for structural failure to occur at load increments above and below analysts' stress limit predictions. They were requested to estimate the relative probabilities of different failure causes, and of failure at each load increment given a specific cause. Three mathematical models are constructed based on the experts' assessment of causes. The experts' overall assessment of prediction strength fits the Saturn V data better than the models do, but a model test option (T-3) based on the overall assessment gives more design change likelihood to overstrength structures than does an older standard test option. T-3 compares unfavorably with the standard option in a cost optimum structural design problem. The report reflects a need for subjective data when objective data are unavailable.

The Genetic Challenges and Opportunities in Advanced Heart Failure.

PubMed

Hannah-Shmouni, Fady; Seidelmann, Sara B; Sirrs, Sandra; Mani, Arya; Jacoby, Daniel

2015-11-01

The causes of heart failure are diverse. Inherited causes represent an important clinical entity and can be divided into 2 major categories: familial and metabolic cardiomyopathies. The distinct features that might be present in early disease states can become broadly overlapping with other diseases, such as in the case of inherited cardiomyopathies (ie, familial hypertrophic cardiomyopathy or mitochondrial diseases). In this review article, we focus on genetic issues related to advanced heart failure. Because of the emerging importance of this topic and its breadth, we sought to focus our discussion on the known genetic forms of heart failure syndromes, genetic testing, and newer data on pharmacogenetics and therapeutics in the treatment of heart failure, to primarily encourage clinicians to place a priority on the diagnosis and treatment of these potentially treatable conditions. Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

The evolving landscape of quality measurement for heart failure

PubMed Central

Fitzgerald, Ashley A.; Allen, Larry A.; Masoudi, Frederick A.

2013-01-01

Heart failure (HF) is a major cause of mortality and morbidity, representing a leading cause of death and hospitalization among U.S. Medicare beneficiaries. Advances in science have generated effective interventions to reduce adverse outcomes in HF, particularly in patients with reduced left ventricular ejection fraction. Unfortunately, effective therapies for heart failure are often not utilized in an effective, safe, timely, equitable, patient-centered, and efficient manner. Further, the risk of adverse outcomes for HF remains high. The last decades have witnessed the growth of efforts to measure and improve the care and outcomes of patients with HF. This paper will review the evolution of quality measurement for HF, including a brief history of quality measurement in medicine; the measures that have been employed to characterize quality in heart failure; how the measures are obtained; how measures are employed; and present and future challenges surrounding quality measurement in heart failure. PMID:22548579

A RAT MODEL OF HEART FAILURE INDUCED BY ISOPROTERENOL AND A HIGH SALT DIET

EPA Science Inventory

Rat models of heart failure (HF) show varied pathology and time to disease outcome, dependent on induction method. We found that subchronic (4wk) isoproterenol (ISO) infusion in Spontaneously Hypertensive Heart Failure (SHHF) rats caused cardiac injury with minimal hypertrophy. O...

Acute-On-Chronic Liver Failure: Causes, Clinical Characteristics and Predictors of Mortality.

PubMed

Tasneem, Abbas Ali; Luck, Nasir Hassan

2017-01-01

To determine the causes, characteristics and predictors of mortality in patients with acute-on-chronic liver failure (ACLF). Cross-sectional study. Department of Hepatogastroenterology, Sindh Institute of Urology and Transplantation, Karachi, from July 2014 to June 2016. All patients with acute-on-chronic liver disease (ACLD) with ages > 12 were included. Patients with ACLF, as defined by the Asian Pacific Association for the Study of Liver (APASL, 2014) were identified. Predictors of mortality were identified using chi-square or Fisher's exact test. Included in the study were 72 patients with mean age of 36.71 years, 46 (63.9%) being males. Among them, 61 developed ACLF. Commonest causes of chronic liver disease (CLD) were chronic viral hepatitis (37, 51.4%) and autoimmune hepatitis (14, 19.4%). Commonest causes of acute liver injury (ALI) were acute viral hepatitis (24, 33.3%) and drug induced liver injury (DILI) (17, 23.6%). Among those with ACLF, 24 (39.3%) patients died with median survival of 17.1 ±13.5 days. Mortality was significantly associated with Child Turcotte Pugh (CTP) score ≥13 (p=0.010), model for end-stage liver disease (MELD) score ≥30 (p=0.001), age >40 years (p=0.036), organ failures (OF) ≥3 (p <0.0001), portosystemic encephalopathy (PSE) (p <0.0001), renal failure (p <0.0001) and urosepsis (p <0.0001). Acute viral hepatitis and DILI are commonest causes of ACLF. Mortality is high in ACLF patients having OF ≥3, CTP ≥13, MELD ≥30, age >40 years, PSE, renal failure and urosepsis.

Effects of geometric factors and shear band patterns on notch sensitivity in bulk metallic glasses

DOE PAGES

Li, Weidong; Bei, Hongbin; Gao, Yanfei

2016-09-21

Our recent experiments in notched bulk metallic glasses have found reduced, or insensitive, or improved strengths, while in many of these cases the ductile strain prior to final failure is enhanced. First, although the inverse notch effect is explained by a shift from shear localization to cavitation failure, it is suggested in this work that the synergistic effect between cohesive fracture at the notched area and shear bands emanating from the notch roots may extend the parametric space for the notch insensitive behavior. Second, the dependence of shear band patterns on notch geometric factors is determined by the Rudnicki-Rice theorymore » and the free-volume-based finite element simulations. Our results suggest conditions for shear band multiplication to take place and for the shear-localization-induced failure to be delayed.« less

Effects of geometric factors and shear band patterns on notch sensitivity in bulk metallic glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Weidong; Bei, Hongbin; Gao, Yanfei

Our recent experiments in notched bulk metallic glasses have found reduced, or insensitive, or improved strengths, while in many of these cases the ductile strain prior to final failure is enhanced. First, although the inverse notch effect is explained by a shift from shear localization to cavitation failure, it is suggested in this work that the synergistic effect between cohesive fracture at the notched area and shear bands emanating from the notch roots may extend the parametric space for the notch insensitive behavior. Second, the dependence of shear band patterns on notch geometric factors is determined by the Rudnicki-Rice theorymore » and the free-volume-based finite element simulations. Our results suggest conditions for shear band multiplication to take place and for the shear-localization-induced failure to be delayed.« less

NALP3-mediated inflammation is a principal cause of progressive renal failure in oxalate nephropathy

PubMed Central

Knauf, Felix; Asplin, John R.; Granja, Ignacio; Schmidt, Insa M.; Moeckel, Gilbert; David, Rachel; Flavell, Richard A.; Aronson, Peter S.

2013-01-01

Oxalate nephropathy with renal failure is caused by multiple disorders causing hyperoxaluria due to either overproduction of oxalate (primary hyperoxaluria) or excessive absorption of dietary oxalate (enteric hyperoxaluria). To study the etiology of renal failure in crystal-induced kidney disease, we created a model of progressive oxalate nephropathy by feeding mice a diet high in soluble oxalate (high oxalate in the absence of dietary calcium). Renal histology was characterized by intratubular calcium-oxalate crystal deposition with an inflammatory response in the surrounding interstitium. Oxalate nephropathy was not found in mice fed a high oxalate diet that also contained calcium. NALP3, also known as cryopyrin, has been implicated in crystal-associated diseases such as gout and silicosis. Mice fed the diet high in soluble oxalate demonstrated increased NALP3 expression in the kidney. Nalp3-null mice were completely protected from the progressive renal failure and death that occurred in wild-type mice fed the diet high in soluble oxalate. NALP3-deficiency did not affect oxalate homeostasis, thereby excluding differences in intestinal oxalate handling to explain the observed phenotype. Thus, progressive renal failure in oxalate nephropathy results primarily from NALP3-mediated inflammation. PMID:23739234

A performance study of unmanned aerial vehicle-based sensor networks under cyber attack

NASA Astrophysics Data System (ADS)

Puchaty, Ethan M.

In UAV-based sensor networks, an emerging area of interest is the performance of these networks under cyber attack. This study seeks to evaluate the performance trade-offs from a System-of-Systems (SoS) perspective between various UAV communications architecture options in the context two missions: tracking ballistic missiles and tracking insurgents. An agent-based discrete event simulation is used to model a sensor communication network consisting of UAVs, military communications satellites, ground relay stations, and a mission control center. Network susceptibility to cyber attack is modeled with probabilistic failures and induced data variability, with performance metrics focusing on information availability, latency, and trustworthiness. Results demonstrated that using UAVs as routers increased network availability with a minimal latency penalty and communications satellite networks were best for long distance operations. Redundancy in the number of links between communication nodes helped mitigate cyber-caused link failures and add robustness in cases of induced data variability by an adversary. However, when failures were not independent, redundancy and UAV routing were detrimental in some cases to network performance. Sensitivity studies indicated that long cyber-caused downtimes and increasing failure dependencies resulted in build-ups of failures and caused significant degradations in network performance.

Severe right heart failure in a patient with Grave's disease.

PubMed

Xenopoulos, N P; Braden, G A; Applegate, R J

1996-11-01

This brief report presents a patient with isolated right heart failure and two rare underlying causes, hyperthyroidism and dysplastic tricuspid valve. Repair of the tricuspid valve and treatment of the hyperthyroidism were both essential for successful treatment of the right heart failure. Most important, recrudescence of hyperthyroidism in this patient was associated with reappearance of florid right heart failure. This report provides further information about a potential linkage of hyperthyroidism and severe right heart failure.

Reestablishment of Native Riparian Species at an Altered High Elevation Site

Treesearch

Franklin J. Chan; Raymond W. Wong

1989-01-01

The failure of a 22-foot-diameter pipe caused an estimated water flow of 40,000 cfs for approximately one hour, which scoured and removed 1.75 million cubic yards of soil and vegetation from Lost Canyon. Mitigation for the damage caused by the pipe failure included reestablishing the lost vegetation. This paper describes the process of reestablishment including the...

Negative Selection Algorithm for Aircraft Fault Detection

NASA Technical Reports Server (NTRS)

Dasgupta, D.; KrishnaKumar, K.; Wong, D.; Berry, M.

2004-01-01

We investigated a real-valued Negative Selection Algorithm (NSA) for fault detection in man-in-the-loop aircraft operation. The detection algorithm uses body-axes angular rate sensory data exhibiting the normal flight behavior patterns, to generate probabilistically a set of fault detectors that can detect any abnormalities (including faults and damages) in the behavior pattern of the aircraft flight. We performed experiments with datasets (collected under normal and various simulated failure conditions) using the NASA Ames man-in-the-loop high-fidelity C-17 flight simulator. The paper provides results of experiments with different datasets representing various failure conditions.

Psychological distress and mortality in systolic heart failure.

PubMed

Pelle, Aline J; Pedersen, Susanne S; Schiffer, Angélique A; Szabó, Balázs; Widdershoven, Jos W; Denollet, Johan

2010-03-01

Depression, anxiety, and type D ("distressed") personality (tendency to experience negative emotions paired with social inhibition) have been associated with poor prognosis in coronary heart disease, but little is known about their role in chronic heart failure. Therefore, we investigated whether these indicators of psychological distress are associated with mortality in chronic heart failure. Consecutive outpatients with chronic heart failure (n=641; 74.3% men; mean age, 66.6+/-10.0 years) filled out a 4-item questionnaire to assess mixed symptoms of anxiety and depression and the 14-item type D scale. End points were defined as all-cause and cardiac mortality. After a mean follow-up of 37.6+/-15.6 months, 123 deaths (76 due to cardiac cause) were recorded. Cumulative hazard functions for elevated anxiety/depression symptoms differed marginally for all-cause (P=0.06), but not cardiac, mortality (P=0.43); type D personality was associated with neither all-cause mortality (P=0.63) nor cardiac mortality (P=0.87). In multivariable analyses, neither elevated anxiety/depression symptoms nor type D personality was associated with all-cause mortality (hazard ratio [HR]=1.18; 95% CI, 0.76 to 1.84; P=0.45 and HR=1.09; 95% CI, 0.67 to 1.77; P=0.73, respectively) or cardiac mortality (HR=1.13; 95% CI, 0.63 to 2.04; P=0.65 and HR=1.16; 95% CI, 0.62 to 2.18; P=0.67). In secondary analyses, a 1-point increase in anxiety/depression (range, 0 to 16) was associated with an 8% increase in risk for all-cause mortality (HR=1.08; 95% CI, 1.01 to 1.15; P=0.02). Neither elevated anxiety/depression symptoms nor type D personality was associated with an increased risk for all-cause or cardiac mortality. Future studies with adequate power and a longer follow-up duration are needed to further elucidate the role of psychological distress in chronic heart failure.

Forecasting overhaul or replacement intervals based on estimated system failure intensity

NASA Astrophysics Data System (ADS)

Gannon, James M.

1994-12-01

System reliability can be expressed in terms of the pattern of failure events over time. Assuming a nonhomogeneous Poisson process and Weibull intensity function for complex repairable system failures, the degree of system deterioration can be approximated. Maximum likelihood estimators (MLE's) for the system Rate of Occurrence of Failure (ROCOF) function are presented. Evaluating the integral of the ROCOF over annual usage intervals yields the expected number of annual system failures. By associating a cost of failure with the expected number of failures, budget and program policy decisions can be made based on expected future maintenance costs. Monte Carlo simulation is used to estimate the range and the distribution of the net present value and internal rate of return of alternative cash flows based on the distributions of the cost inputs and confidence intervals of the MLE's.

Analyses of Transistor Punchthrough Failures

NASA Technical Reports Server (NTRS)

Nicolas, David P.

1999-01-01

The failure of two transistors in the Altitude Switch Assembly for the Solid Rocket Booster followed by two additional failures a year later presented a challenge to failure analysts. These devices had successfully worked for many years on numerous missions. There was no history of failures with this type of device. Extensive checks of the test procedures gave no indication for a source of the cause. The devices were manufactured more than twenty years ago and failure information on this lot date code was not readily available. External visual exam, radiography, PEID, and leak testing were performed with nominal results Electrical testing indicated nearly identical base-emitter and base-collector characteristics (both forward and reverse) with a low resistance short emitter to collector. These characteristics are indicative of a classic failure mechanism called punchthrough. In failure analysis punchthrough refers to an condition where a relatively low voltage pulse causes the device to conduct very hard producing localized areas of thermal runaway or "hot spots". At one or more of these hot spots, the excessive currents melt the silicon. Heavily doped emitter material diffuses through the base region to the collector forming a diffusion pipe shorting the emitter to base to collector. Upon cooling, an alloy junction forms between the pipe and the base region. Generally, the hot spot (punch-through site) is under the bond and no surface artifact is visible. The devices were delidded and the internal structures were examined microscopically. The gold emitter lead was melted on one device, but others had anomalies in the metallization around the in-tact emitter bonds. The SEM examination confirmed some anomalies to be cosmetic defects while other anomalies were artifacts of the punchthrough site. Subsequent to these analyses, the contractor determined that some irregular testing procedures occurred at the time of the failures heretofore unreported. These testing irregularities involved the use of a breakout box and were the likely cause of the failures. There was no evidence to suggest a generic failure mechanism was responsible for the failure of these transistors.

Accelerated Implantable Defibrillator Battery Depletion Secondary to Lithium Cluster Formation: A Case Series.

PubMed

Aggarwal, Ashim; Sarmiento, Joseph J; Charles, David R; Parr, Alan R; Baman, Timir S

2016-04-01

Device failure from unanticipated and precipitous battery depletion is uncommon but can be life-threatening. Multiple mechanisms of battery failure have been previously described in the medical literature. However, in this current case series, we describe the largest cohort of patients (n = 4) with St. Jude (St. Paul, MN, USA) early implantable defibrillator battery depletion attributable to lithium cluster formation causing short circuit and high current drain. Clinicians must be aware of this occult cause of device failure and more studies are needed to determine its true prevalence. © 2015 Wiley Periodicals, Inc.

Demonstrating the Safety and Reliability of a New System or Spacecraft: Incorporating Analyses and Reviews of the Design and Processing in Determining the Number of Tests to be Conducted

NASA Technical Reports Server (NTRS)

Vesely, William E.; Colon, Alfredo E.

2010-01-01

Design Safety/Reliability is associated with the probability of no failure-causing faults existing in a design. Confidence in the non-existence of failure-causing faults is increased by performing tests with no failure. Reliability-Growth testing requirements are based on initial assurance and fault detection probability. Using binomial tables generally gives too many required tests compared to reliability-growth requirements. Reliability-Growth testing requirements are based on reliability principles and factors and should be used.

The Epidemiology of Hospital Death Following Pediatric Severe Sepsis: When, Why, and How Children With Sepsis Die.

PubMed

Weiss, Scott L; Balamuth, Fran; Hensley, Josey; Fitzgerald, Julie C; Bush, Jenny; Nadkarni, Vinay M; Thomas, Neal J; Hall, Mark; Muszynski, Jennifer

2017-09-01

The epidemiology of in-hospital death after pediatric sepsis has not been well characterized. We investigated the timing, cause, mode, and attribution of death in children with severe sepsis, hypothesizing that refractory shock leading to early death is rare in the current era. Retrospective observational study. Emergency departments and ICUs at two academic children's hospitals. Seventy-nine patients less than 18 years old treated for severe sepsis/septic shock in 2012-2013 who died prior to hospital discharge. None. Time to death from sepsis recognition, cause and mode of death, and attribution of death to sepsis were determined from medical records. Organ dysfunction was assessed via daily Pediatric Logistic Organ Dysfunction-2 scores for 7 days preceding death with an increase greater than or equal to 5 defined as worsening organ dysfunction. The median time to death was 8 days (interquartile range, 1-12 d) with 25%, 35%, and 49% of cumulative deaths within 1, 3, and 7 days of sepsis recognition, respectively. The most common cause of death was refractory shock (34%), then multiple organ dysfunction syndrome after shock recovery (27%), neurologic injury (19%), single-organ respiratory failure (9%), and nonseptic comorbidity (6%). Early deaths (≤ 3 d) were mostly due to refractory shock in young, previously healthy patients while multiple organ dysfunction syndrome predominated after 3 days. Mode of death was withdrawal in 72%, unsuccessful cardiopulmonary resuscitation in 22%, and irreversible loss of neurologic function in 6%. Ninety percent of deaths were attributable to acute or chronic manifestations of sepsis. Only 23% had a rise in Pediatric Logistic Organ Dysfunction-2 that indicated worsening organ dysfunction. Refractory shock remains a common cause of death in pediatric sepsis, especially for early deaths. Later deaths were mostly attributable to multiple organ dysfunction syndrome, neurologic, and respiratory failure after life-sustaining therapies were limited. A pattern of persistent, rather than worsening, organ dysfunction preceded most deaths.