On the Survival Time of a Duplex System: A Sokhotski-Plemelj Problem

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Edmond J. Vanderperre

2008-12-01

Full Text Available We analyze the survival time of a renewable duplex system characterized by warm standby and subjected to a priority rule. In order to obtain the Laplace transform of the survival function, we employ a stochastic process endowed with time-dependent transition measures satisfying coupled partial differential equations. The solution procedure is based on the theory of sectionally holomorphic functions combined with the notion of dual transforms. Finally, we introduce a security interval related to a prescribed security level and a suitable risk criterion based on the survival function of the system. As an example, we consider the particular case of deterministic repair. A computer-plotted graph displays the survival function together with the security interval corresponding to a security level of 90%.

Developing a scalable modeling architecture for studying survivability technologies

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Mohammad, Syed; Bounker, Paul; Mason, James; Brister, Jason; Shady, Dan; Tucker, David

2006-05-01

To facilitate interoperability of models in a scalable environment, and provide a relevant virtual environment in which Survivability technologies can be evaluated, the US Army Research Development and Engineering Command (RDECOM) Modeling Architecture for Technology Research and Experimentation (MATREX) Science and Technology Objective (STO) program has initiated the Survivability Thread which will seek to address some of the many technical and programmatic challenges associated with the effort. In coordination with different Thread customers, such as the Survivability branches of various Army labs, a collaborative group has been formed to define the requirements for the simulation environment that would in turn provide them a value-added tool for assessing models and gauge system-level performance relevant to Future Combat Systems (FCS) and the Survivability requirements of other burgeoning programs. An initial set of customer requirements has been generated in coordination with the RDECOM Survivability IPT lead, through the Survivability Technology Area at RDECOM Tank-automotive Research Development and Engineering Center (TARDEC, Warren, MI). The results of this project are aimed at a culminating experiment and demonstration scheduled for September, 2006, which will include a multitude of components from within RDECOM and provide the framework for future experiments to support Survivability research. This paper details the components with which the MATREX Survivability Thread was created and executed, and provides insight into the capabilities currently demanded by the Survivability faculty within RDECOM.

Sex-related time-dependent variations in post-stroke survival-evidence of a female stroke survival advantage

DEFF Research Database (Denmark)

Olsen, Tom Skyhøj; Dehlendorff, Christian; Andersen, Klaus Kaae

2007-01-01

the influence of gender on post-stroke mortality, from the time of admission through the subsequent years until death or censoring ( mean follow-up time: 538 days). All patients underwent an evaluation including stroke severity, computed tomography and cardiovascular risk factors. Independent predictors......Background: Women live longer than men, yet most studies show that gender has no influence on survival after stroke. Methods: A registry was started in 2001, with the aim of registering all hospitalized stroke patients in Denmark, and it now holds 39,484 patients of which 48% are female. We studied...... of death were identified by means of a survival model based on 22,222 individuals with a complete data set. Results: Females were older and had severer stroke. Interestingly, the risk of death between genders was time dependent. The female/male stroke mortality rate favoured women from the first day...

Survival and development of horseshoe crab (Limulus polyphemus) embryos and larvae in hypersaline conditions.

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Ehlinger, Gretchen S; Tankersley, Richard A

2004-04-01

The horseshoe crab Limulus polyphemus spawns in the mid- to upper intertidal zone where females deposit eggs in nests below the sediment surface. Although adult crabs generally inhabit subtidal regions of estuaries with salinities from 5 to 34 ppt, developing embryos and larvae within nests are often exposed to more extreme conditions of salinity and temperature during summer spawning periods. To test whether these conditions have a negative impact on early development and survival, we determined development time, survival, and molt cycle duration for L. polyphemus embryos and larvae raised at 20 combinations of salinity (range: 30-60 ppt) and temperature (range: 25-40 degrees C). Additionally, the effect of hyperosmotic and hypoosmotic shock on the osmolarity of the perivitelline fluid of embryos was determined at salinities between 5 and 90 ppt. The embryos completed their development and molted at salinities below 60 ppt, yet failed to develop at temperatures of 35 degrees C or higher. Larval survival was high at salinities of 10-70 ppt but declined significantly at more extreme salinities (i.e., 5, 80, and 90 ppt). Perivitelline fluid remained nearly isoosmotic over the range of salinities tested. Results indicate that temperature and salinity influence the rate of crab development, but only the extremes of these conditions have an effect on survival.

[Survival time of HIV/AIDS cases and related factors in Beijing, 1995-2015].

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Li, Y; Wang, J; He, S F; Chen, J; Lu, H Y

2017-11-10

Objective: To analyze the survival time of HIV/AIDS cases and related factors in Beijing from 1995 to 2015. Methods: A retrospective cohort study was conducted to analyze the data of 12 874 HIV/AIDS cases. The data were collected from Chinese HIV/AIDS Comprehensive Information Management System. Life table method was applied to calculate the survival proportion, and Cox proportion hazard regression model were used to identify the factors related with survival time. Results: Among 12 874 HIV/AIDS cases, 303 (2.4%) died of AIDS related diseases; 9 346 (72.6%) received antiretroviral therapy. The average survival time was 226.5 months (95 %CI : 223.0-230.1), and the survival rates of 1, 5, 10, and 15 years were 98.2%, 96.4%, 93.2%, and 91.9% respectively. Multivariate Cox proportion hazard regression model showed that AIDS phase ( HR =1.439, 95 %CI : 1.041-1.989), heterosexual transmission ( HR =1.646, 95 %CI : 1.184-2.289), being married ( HR =2.186, 95 %CI : 1.510-3.164); older age (≥60 years) at diagnosis ( HR =6.608, 95 %CI : 3.546-12.316); lower CD(4)(+)T cell counts at diagnosis (<350 cells/μl) ( HR =8.711, 95 %CI : 5.757-13.181); receiving no antiretroviral therapy (ART) ( HR =18.223, 95 %CI : 13.317-24.937) were the high risk factors influencing the survival of AIDS patients compared with HIV phase, homosexual transmission, being unmarried, younger age (≤30 years), higher CD(4)(+)T cell count (≥350 cell/μl) and receiving ART. Conclusion: The average survival time of HIV/AIDS cases was 226.5 months after diagnoses. Receiving ART, higher CD(4)(+)T cell counts at the first test, HIV phase, younger age, being unmarried and the homosexual transmission were related to the longer survival time of HIV/AIDS cases. Receiving no ART, the lower CD(4)(+)T cell counts at the first test, AIDS phase, older age, being married and heterosexual transmission indicated higher risk of death due to AIDS.

Effect of temperature and relative humidity on the development times and survival of Synopsyllus fonquerniei and Xenopsylla cheopis, the flea vectors of plague in Madagascar.

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Kreppel, Katharina S; Telfer, Sandra; Rajerison, Minoarisoa; Morse, Andy; Baylis, Matthew

2016-02-11

Plague, a zoonosis caused by Yersinia pestis, is found in Asia, the Americas but mainly in Africa, with the island of Madagascar reporting almost one third of human cases worldwide. In the highlands of Madagascar, plague is transmitted predominantly by two flea species which coexist on the island, but differ in their distribution. The endemic flea, Synopsyllus fonquerniei, dominates flea communities on rats caught outdoors, while the cosmopolitan flea, Xenopsylla cheopis, is found mostly on rats caught in houses. Additionally S. fonquerniei seems restricted to areas above 800 m. Climatic constraints on the development of the two main vectors of plague could explain the differences in their distribution and the seasonal changes in their abundance. Here we present the first study on effects of temperature and relative humidity on the immature stages of both vector species. We examined the two species' temperature and humidity requirements under experimental conditions at five different temperatures and two relative humidities. By employing multivariate and survival analysis we established the impact of temperature and relative humidity on development times and survival for both species. Using degree-day analysis we then predicted the average developmental threshold for larvae to reach pupation and for pupae to complete development under each treatment. This analysis was undertaken separately for the two relative humidities and for the two species. Development times and time to death differed significantly, with the endemic S. fonquerniei taking on average 1.79 times longer to complete development and having a shorter time to death than X. cheopis under adverse conditions with high temperature and low humidity. Temperature had a significant effect on the development times of flea larvae and pupae. While humidity did not affect the development times of either species, it did influence the time of death of S. fonquerniei. Using degree-day analysis we estimated an

Clinical findings and survival time in dogs with advanced heart failure.

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Beaumier, Amelie; Rush, John E; Yang, Vicky K; Freeman, Lisa M

2018-04-10

Dogs with advanced heart failure are a clinical challenge for veterinarians but there are no studies reporting clinical features and outcome of this population. To describe clinical findings and outcome of dogs with advanced heart failure caused by degenerative mitral valve disease (DMVD). Fifty-four dogs with advanced heart failure because of DMVD. For study purposes, advanced heart failure was defined as recurrence of congestive heart failure signs despite receiving the initially prescribed dose of pimobendan, angiotensin-converting-enzyme inhibitor (ACEI), and furosemide >4 mg/kg/day. Data were collected for the time of diagnosis of Stage C heart failure and time of diagnosis of advanced heart failure. Date of death was recorded. At the diagnosis of advanced heart failure, doses of pimobendan (n = 30), furosemide (n = 28), ACEI (n = 13), and spironolactone (n = 4) were increased, with ≥1 new medications added in most dogs. After initial diagnosis of advanced heart failure, 38 (70%) dogs had additional medications adjustments (median = 2 [range, 0-27]), with the final total medication number ranging from 2-10 (median = 5). Median survival time after diagnosis of advanced heart failure was 281 days (range, 3-885 days). Dogs receiving a furosemide dose >6.70 mg/kg/day had significantly longer median survival times (402 days [range, 3-885 days] versus 129 days [range 9-853 days]; P = .017). Dogs with advanced heart failure can have relatively long survival times. Higher furosemide dose and non-hospitalization were associated with longer survival. Copyright © 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Modelling the joint distribution of competing risks survival times using copula functions

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Kaishev, V. K.; Haberman, S.; Dimitrova, D. S.

2005-01-01

The problem of modelling the joint distribution of survival times in a competing risks model, using copula functions is considered. In order to evaluate this joint distribution and the related overall survival function, a system of non-linear differential equations is solved, which relates the crude and net survival functions of the modelled competing risks, through the copula. A similar approach to modelling dependent multiple decrements was applied by Carriere (1994) who used a Gaussian cop...

Association of Bystander Cardiopulmonary Resuscitation and Survival According to Ambulance Response Times After Out-of-Hospital Cardiac Arrest.

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Rajan, Shahzleen; Wissenberg, Mads; Folke, Fredrik; Hansen, Steen Møller; Gerds, Thomas A; Kragholm, Kristian; Hansen, Carolina Malta; Karlsson, Lena; Lippert, Freddy K; Køber, Lars; Gislason, Gunnar H; Torp-Pedersen, Christian

2016-12-20

Bystander-initiated cardiopulmonary resuscitation (CPR) increases patient survival after out-of-hospital cardiac arrest, but it is unknown to what degree bystander CPR remains positively associated with survival with increasing time to potential defibrillation. The main objective was to examine the association of bystander CPR with survival as time to advanced treatment increases. We studied 7623 out-of-hospital cardiac arrest patients between 2005 and 2011, identified through the nationwide Danish Cardiac Arrest Registry. Multiple logistic regression analysis was used to examine the association between time from 911 call to emergency medical service arrival (response time) and survival according to whether bystander CPR was provided (yes or no). Reported are 30-day survival chances with 95% bootstrap confidence intervals. With increasing response times, adjusted 30-day survival chances decreased for both patients with bystander CPR and those without. However, the contrast between the survival chances of patients with versus without bystander CPR increased over time: within 5 minutes, 30-day survival was 14.5% (95% confidence interval [CI]: 12.8-16.4) versus 6.3% (95% CI: 5.1-7.6), corresponding to 2.3 times higher chances of survival associated with bystander CPR; within 10 minutes, 30-day survival chances were 6.7% (95% CI: 5.4-8.1) versus 2.2% (95% CI: 1.5-3.1), corresponding to 3.0 times higher chances of 30-day survival associated with bystander CPR. The contrast in 30-day survival became statistically insignificant when response time was >13 minutes (bystander CPR vs no bystander CPR: 3.7% [95% CI: 2.2-5.4] vs 1.5% [95% CI: 0.6-2.7]), but 30-day survival was still 2.5 times higher associated with bystander CPR. Based on the model and Danish out-of-hospital cardiac arrest statistics, an additional 233 patients could potentially be saved annually if response time was reduced from 10 to 5 minutes and 119 patients if response time was reduced from 7 (the median

Measurement of Survival Time in Brachionus Rotifers: Synchronization of Maternal Conditions.

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Kaneko, Gen; Yoshinaga, Tatsuki; Gribble, Kristin E; Welch, David M; Ushio, Hideki

2016-07-22

Rotifers are microscopic cosmopolitan zooplankton used as models in ecotoxicological and aging studies due to their several advantages such as short lifespan, ease of culture, and parthenogenesis that enables clonal culture. However, caution is required when measuring their survival time as it is affected by maternal age and maternal feeding conditions. Here we provide a protocol for powerful and reproducible measurement of the survival time in Brachionus rotifers following a careful synchronization of culture conditions over several generations. Empirically, poor synchronization results in early mortality and a gradual decrease in survival rate, thus resulting in weak statistical power. Indeed, under such conditions, calorie restriction (CR) failed to significantly extend the lifespan of B. plicatilis although CR-induced longevity has been demonstrated with well-synchronized rotifer samples in past and present studies. This protocol is probably useful for other invertebrate models, including the fruitfly Drosophila melanogaster and the nematode Caenorhabditis elegans, because maternal age effects have also been reported in these species.

End points for adjuvant therapy trials: has the time come to accept disease-free survival as a surrogate end point for overall survival?

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Gill, Sharlene; Sargent, Daniel

2006-06-01

The intent of adjuvant therapy is to eradicate micro-metastatic residual disease following curative resection with the goal of preventing or delaying recurrence. The time-honored standard for demonstrating efficacy of new adjuvant therapies is an improvement in overall survival (OS). This typically requires phase III trials of large sample size with lengthy follow-up. With the intent of reducing the cost and time of completing such trials, there is considerable interest in developing alternative or surrogate end points. A surrogate end point may be employed as a substitute to directly assess the effects of an intervention on an already accepted clinical end point such as mortality. When used judiciously, surrogate end points can accelerate the evaluation of new therapies, resulting in the more timely dissemination of effective therapies to patients. The current review provides a perspective on the suitability and validity of disease-free survival (DFS) as an alternative end point for OS. Criteria for establishing surrogacy and the advantages and limitations associated with the use of DFS as a primary end point in adjuvant clinical trials and as the basis for approval of new adjuvant therapies are discussed.

Determine the Influence of Time Held in “Knockdown” Anesthesia on Survival and Stress of Surgically Implanted Juvenile Salmonids

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Woodley, Christa M.; Wagner, Katie A.; Knox, Kasey M.

2012-01-31

The Juvenile Salmon Acoustic Telemetry System (JSATS) was developed for the U.S. Army Corp of Engineers Portland District (USACE) to address questions related to survival and performance measures of juvenile salmonids as they pass through the Federal Columbia River Power System (FCRPS). Researchers using JSATS acoustic transmitters (ATs) were tasked with standardizing the surgical implantation procedure to ensure that the stressors of handling and surgery on salmonids were consistent and less likely to cause effects of tagging in survival studies. Researchers questioned whether the exposure time in 'knockdown' anesthesia (or induction) to prepare fish for surgery could influence the survival of study fish (CBSPSC 2011). Currently, fish are held in knockdown anesthesia after they reach Stage 4 anesthesia until the completion of the surgical implantation of a transmitter, varies from 5 to 15 minutes for studies conducted in the Columbia Basin. The Columbia Basin Surgical Protocol Steering Committee (CBSPSC ) expressed concern that its currently recommended 10-minute maximum time limit during which fish are held in anesthetic - tricaine methanesulfonate (MS-222, 80 mg L-1 water) - could increase behavioral and physiological costs, and/or decrease survival of outmigrating juvenile salmonids. In addition, the variability in the time fish are held at Stage 4 could affect the data intended for direct comparison of fish within or among survival studies. Under the current recommended protocol, if fish exceed the 10-minute time limit, they are to be released without surgical implantation, thereby increasing the number of fish handled and endangered species 'take' at the bypass systems for FCRPS survival studies.

First recovery in anorexia nervosa patients in the long-term course: a discrete-time survival analysis.

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Herzog, W; Schellberg, D; Deter, H C

1997-02-01

The results of a 12-year follow-up study of occurrence and timing of first recovery in 69 hospitalized patients with severe anorexia nervosa (AN) are presented. For the first time discrete-time survival analysis methods were used to determine the likelihood of recovery in AN patients. Furthermore, predictors gleaned from pretreatment-posttreatment studies of long-term outcome in AN could be evaluated as to their effect on a change in the time course structure of the likelihood of first recovery. Results show that AN condition did not improve until after 6 years after the first inpatient treatment in 50% of patients. However, a restricter-type AN and low serum creatinine levels were predictors for earlier recovery. One specific effect was that AN patients who show purging behavior in combination with additional social disturbances have a lower chance of recovering. The use of discrete-time survival analysis methodology in further prospective studies will contribute to the development of more tailored treatment of AN, which also takes the individual phase of illness and specific aspects of the symptomatology into account.

Effects of Rearing Density on Survival, Growth, and Development of the Ladybird Coleomegilla maculata in Culture

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Eric W. Riddick

2015-10-01

Full Text Available Our research focuses on developing techniques to rear ladybird beetles (Coleoptera: Coccinellidae. We evaluated the effects of rearing density on survival, growth, and development of Coleomegilla maculata. The hypothesis that a low to moderate rearing density has limited or no effects on survival and development was tested. C. maculata first instars were reared to pupae at a density of 1, 5, 10, 15, or 20 individuals per arena (2.5 cm high, 9.0 cm diameter, and 159 cm3 volume and fed powdered brine shrimp (Artemia franciscana eggs. More larvae survived at the 1 and 5 densities, but no differences were detected between the 10, 15, or 20 densities. Median survival rate was at least 90% for larvae and 100% for pupae at the 10, 15, and 20 densities. Development time, body weight, and sex ratio were unaffected by rearing density. Overall, this study suggests that C. maculata larvae can be reared successfully at a density of 20 larvae/159 cm3 (≈ 0.126 larvae/cm3 in containers provisioned with powdered A. franciscana eggs. Scaling-up the size of containers, and C. maculata density in these containers, should be possible.

Causal inference for long-term survival in randomised trials with treatment switching: Should re-censoring be applied when estimating counterfactual survival times?

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Latimer, N.R.; White, I.R.; Abrams, K.R.; Sieburt, U.

2017-01-01

Treatment switching often has a crucial impact on estimates of effectiveness and cost-effectiveness of new oncology treatments. Rank preserving structural failure time models (RPSFTM) and two-stage estimation (TSE) methods estimate ‘counterfactual’ (i.e. had there been no switching) survival times and incorporate re-censoring to guard against informative censoring in the counterfactual dataset. However, re-censoring causes a loss of longer term survival information which is problematic when e...

Using Concurrent Cardiovascular Information to Augment Survival Time Data from Orthostatic Tilt Tests

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Feiveson, Alan H.; Fiedler, James; Lee, Stuart M. M.; Westby, Christian M.; Stenger, Michael B.; Platts, Steven H.

2014-01-01

Orthostatic Intolerance (OI) is the propensity to develop symptoms of fainting during upright standing. OI is associated with changes in heart rate, blood pressure and other measures of cardiac function. Problem: NASA astronauts have shown increased susceptibility to OI on return from space missions. Current methods for counteracting OI in astronauts include fluid loading and the use of compression garments. Multivariate trajectory spread is greater as OI increases. Pairwise comparisons at the same time within subjects allows incorporation of pass/fail outcomes. Path length, convex hull area, and covariance matrix determinant do well as statistics to summarize this spread Missing data problems Time series analysis need many more time points per OTT session treatment of trend? how incorporate survival information?

Survival and psychomotor development with early betaine treatment in patients with severe methylenetetrahydrofolate reductase deficiency.

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Diekman, Eugene F; de Koning, Tom J; Verhoeven-Duif, Nanda M; Rovers, Maroeska M; van Hasselt, Peter M

2014-02-01

The impact of betaine treatment on outcome in patients with severe methylenetetrahydrofolate reductase (MTHFR) deficiency is presently unclear. To investigate the effect of betaine treatment on development and survival in patients with severe MTHFR deficiency. MEDLINE, EMBASE, and Cochrane databases between January 1960 and December 2012. Studies that described patients with severe MTHFR deficiency who received betaine treatment. We identified 15 case reports and case series, totaling 36 patients. Data included the following: (1) families with 2 or more patients with severe MTHFR deficiency, of whom at least 1 received betaine, or (2) single patients with severe MTHFR deficiency treated with betaine. To define severe MTHFR deficiency, methionine, homocysteine, MTHFR enzyme activity in fibroblasts, or mutations (in the MTHFR gene) had to be described as well as the effect of treatment (survival and/or psychomotor development). We compared the outcome in treated vs untreated patients and early- vs late-treated patients. Sensitivity analysis was performed to address definition of early treatment. To further assess the impact of treatment on mortality, we performed a subanalysis in families with at least 1 untreated deceased patient. Survival and psychomotor development. Eleven of 36 patients (31%) died. All deaths occurred in patients who did not receive treatment or in patients in whom treatment was delayed. In contrast, all 5 early-treated patients survived. Subgroup analysis of patients with deceased siblings-their genotypically identical controls-revealed that betaine treatment prevented mortality (P = .002). In addition, psychomotor development in surviving patients treated with betaine was normal in all 5 early-treated patients but in none of the 19 surviving patients with delayed treatment (P psychomotor development in patients with severe MTHFR deficiency, highlighting the importance of timely recognition through newborn screening.

Association of bystander cardiopulmonary resuscitation and survival according to ambulance response-times after out-of-hospital cardiac arrest

DEFF Research Database (Denmark)

Rajan, Shahzleen; Wissenberg, Mads; Folke, Fredrik

2016-01-01

30-day survival chances decreased for both patients with bystander CPR and those without. However, the contrast between the survival chances of patients with versus without bystander CPR increased over time: within 5 minutes, 30-day survival was 14.5% (95% confidence interval [CI]: 12.8-16.4) versus...... 6.3% (95% CI: 5.1-7.6), corresponding to 2.3 times higher chances of survival associated with bystander CPR; within 10 minutes, 30-day survival chances were 6.7% (95% CI: 5.4-8.1) versus 2.2% (95% CI: 1.5-3.1), corresponding to 3.0 times higher chances of 30-day survival associated with bystander...... CPR. The contrast in 30-day survival became statistically insignificant when response time was >13 minutes (bystander CPR vs no bystander CPR: 3.7% [95% CI: 2.2-5.4] vs 1.5% [95% CI: 0.6-2.7]), but 30-day survival was still 2.5 times higher associated with bystander CPR. Based on the model and Danish...

Mediation Analysis with Survival Outcomes: Accelerated Failure Time vs. Proportional Hazards Models.

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Gelfand, Lois A; MacKinnon, David P; DeRubeis, Robert J; Baraldi, Amanda N

2016-01-01

Survival time is an important type of outcome variable in treatment research. Currently, limited guidance is available regarding performing mediation analyses with survival outcomes, which generally do not have normally distributed errors, and contain unobserved (censored) events. We present considerations for choosing an approach, using a comparison of semi-parametric proportional hazards (PH) and fully parametric accelerated failure time (AFT) approaches for illustration. We compare PH and AFT models and procedures in their integration into mediation models and review their ability to produce coefficients that estimate causal effects. Using simulation studies modeling Weibull-distributed survival times, we compare statistical properties of mediation analyses incorporating PH and AFT approaches (employing SAS procedures PHREG and LIFEREG, respectively) under varied data conditions, some including censoring. A simulated data set illustrates the findings. AFT models integrate more easily than PH models into mediation models. Furthermore, mediation analyses incorporating LIFEREG produce coefficients that can estimate causal effects, and demonstrate superior statistical properties. Censoring introduces bias in the coefficient estimate representing the treatment effect on outcome-underestimation in LIFEREG, and overestimation in PHREG. With LIFEREG, this bias can be addressed using an alternative estimate obtained from combining other coefficients, whereas this is not possible with PHREG. When Weibull assumptions are not violated, there are compelling advantages to using LIFEREG over PHREG for mediation analyses involving survival-time outcomes. Irrespective of the procedures used, the interpretation of coefficients, effects of censoring on coefficient estimates, and statistical properties should be taken into account when reporting results.

Mediation Analysis with Survival Outcomes: Accelerated Failure Time vs. Proportional Hazards Models

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Gelfand, Lois A.; MacKinnon, David P.; DeRubeis, Robert J.; Baraldi, Amanda N.

2016-01-01

Objective: Survival time is an important type of outcome variable in treatment research. Currently, limited guidance is available regarding performing mediation analyses with survival outcomes, which generally do not have normally distributed errors, and contain unobserved (censored) events. We present considerations for choosing an approach, using a comparison of semi-parametric proportional hazards (PH) and fully parametric accelerated failure time (AFT) approaches for illustration. Method: We compare PH and AFT models and procedures in their integration into mediation models and review their ability to produce coefficients that estimate causal effects. Using simulation studies modeling Weibull-distributed survival times, we compare statistical properties of mediation analyses incorporating PH and AFT approaches (employing SAS procedures PHREG and LIFEREG, respectively) under varied data conditions, some including censoring. A simulated data set illustrates the findings. Results: AFT models integrate more easily than PH models into mediation models. Furthermore, mediation analyses incorporating LIFEREG produce coefficients that can estimate causal effects, and demonstrate superior statistical properties. Censoring introduces bias in the coefficient estimate representing the treatment effect on outcome—underestimation in LIFEREG, and overestimation in PHREG. With LIFEREG, this bias can be addressed using an alternative estimate obtained from combining other coefficients, whereas this is not possible with PHREG. Conclusions: When Weibull assumptions are not violated, there are compelling advantages to using LIFEREG over PHREG for mediation analyses involving survival-time outcomes. Irrespective of the procedures used, the interpretation of coefficients, effects of censoring on coefficient estimates, and statistical properties should be taken into account when reporting results. PMID:27065906

Mediation Analysis with Survival Outcomes: Accelerated Failure Time Versus Proportional Hazards Models

Directory of Open Access Journals (Sweden)

Lois A Gelfand

2016-03-01

Full Text Available Objective: Survival time is an important type of outcome variable in treatment research. Currently, limited guidance is available regarding performing mediation analyses with survival outcomes, which generally do not have normally distributed errors, and contain unobserved (censored events. We present considerations for choosing an approach, using a comparison of semi-parametric proportional hazards (PH and fully parametric accelerated failure time (AFT approaches for illustration.Method: We compare PH and AFT models and procedures in their integration into mediation models and review their ability to produce coefficients that estimate causal effects. Using simulation studies modeling Weibull-distributed survival times, we compare statistical properties of mediation analyses incorporating PH and AFT approaches (employing SAS procedures PHREG and LIFEREG, respectively under varied data conditions, some including censoring. A simulated data set illustrates the findings.Results: AFT models integrate more easily than PH models into mediation models. Furthermore, mediation analyses incorporating LIFEREG produce coefficients that can estimate causal effects, and demonstrate superior statistical properties. Censoring introduces bias in the coefficient estimate representing the treatment effect on outcome – underestimation in LIFEREG, and overestimation in PHREG. With LIFEREG, this bias can be addressed using an alternative estimate obtained from combining other coefficients, whereas this is not possible with PHREG.Conclusions: When Weibull assumptions are not violated, there are compelling advantages to using LIFEREG over PHREG for mediation analyses involving survival-time outcomes. Irrespective of the procedures used, the interpretation of coefficients, effects of censoring on coefficient estimates, and statistical properties should be taken into account when reporting results.

Survival and prognostic factors at time of diagnosis in high-grade appendicular osteosarcoma

DEFF Research Database (Denmark)

Colding-Rasmussen, Thomas; Thorn, Andrea Pohly; Horstmann, Peter

2018-01-01

BACKGROUND: Survival of patients with high-grade osteosarcoma (HOS), the most common primary bone cancer, has not improved significantly the last 30 years and the disease remains a major challenge. The purpose of this study is to evaluate survival in relation to prognostic factors at time of diag...

Integrated survival analysis using an event-time approach in a Bayesian framework.

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Walsh, Daniel P; Dreitz, Victoria J; Heisey, Dennis M

2015-02-01

Event-time or continuous-time statistical approaches have been applied throughout the biostatistical literature and have led to numerous scientific advances. However, these techniques have traditionally relied on knowing failure times. This has limited application of these analyses, particularly, within the ecological field where fates of marked animals may be unknown. To address these limitations, we developed an integrated approach within a Bayesian framework to estimate hazard rates in the face of unknown fates. We combine failure/survival times from individuals whose fates are known and times of which are interval-censored with information from those whose fates are unknown, and model the process of detecting animals with unknown fates. This provides the foundation for our integrated model and permits necessary parameter estimation. We provide the Bayesian model, its derivation, and use simulation techniques to investigate the properties and performance of our approach under several scenarios. Lastly, we apply our estimation technique using a piece-wise constant hazard function to investigate the effects of year, age, chick size and sex, sex of the tending adult, and nesting habitat on mortality hazard rates of the endangered mountain plover (Charadrius montanus) chicks. Traditional models were inappropriate for this analysis because fates of some individual chicks were unknown due to failed radio transmitters. Simulations revealed biases of posterior mean estimates were minimal (≤ 4.95%), and posterior distributions behaved as expected with RMSE of the estimates decreasing as sample sizes, detection probability, and survival increased. We determined mortality hazard rates for plover chicks were highest at birth weights and/or whose nest was within agricultural habitats. Based on its performance, our approach greatly expands the range of problems for which event-time analyses can be used by eliminating the need for having completely known fate data.

Integrated survival analysis using an event-time approach in a Bayesian framework

Science.gov (United States)

Walsh, Daniel P.; Dreitz, VJ; Heisey, Dennis M.

2015-01-01

Event-time or continuous-time statistical approaches have been applied throughout the biostatistical literature and have led to numerous scientific advances. However, these techniques have traditionally relied on knowing failure times. This has limited application of these analyses, particularly, within the ecological field where fates of marked animals may be unknown. To address these limitations, we developed an integrated approach within a Bayesian framework to estimate hazard rates in the face of unknown fates. We combine failure/survival times from individuals whose fates are known and times of which are interval-censored with information from those whose fates are unknown, and model the process of detecting animals with unknown fates. This provides the foundation for our integrated model and permits necessary parameter estimation. We provide the Bayesian model, its derivation, and use simulation techniques to investigate the properties and performance of our approach under several scenarios. Lastly, we apply our estimation technique using a piece-wise constant hazard function to investigate the effects of year, age, chick size and sex, sex of the tending adult, and nesting habitat on mortality hazard rates of the endangered mountain plover (Charadrius montanus) chicks. Traditional models were inappropriate for this analysis because fates of some individual chicks were unknown due to failed radio transmitters. Simulations revealed biases of posterior mean estimates were minimal (≤ 4.95%), and posterior distributions behaved as expected with RMSE of the estimates decreasing as sample sizes, detection probability, and survival increased. We determined mortality hazard rates for plover chicks were highest at birth weights and/or whose nest was within agricultural habitats. Based on its performance, our approach greatly expands the range of problems for which event-time analyses can be used by eliminating the need for having completely known fate data.

Childhood cancer survival in Switzerland (1976-2013): Time-trends and predictors.

Science.gov (United States)

Schindler, Matthias; Belle, Fabiën N; Grotzer, Michael A; von der Weid, Nicolas X; Kuehni, Claudia E

2017-01-01

Population-based studies on childhood cancer survival are key to monitor progress against cancer and to detect potential differences between regions and other subgroups in the population. We investigated time trends and factors associated with childhood cancer survival on a national level in Switzerland, from 1976 to 2013. We extracted data from the population-based Swiss Childhood Cancer Registry of 5,776 children (age 0-14 years) diagnosed with cancer from 1985 to 2014 in Switzerland. We calculated age-adjusted 5-year survival, defined the annual reduction in risk of death (ARR), and explored associations of survival with clinical and demographic factors. Overall, 5-year survival improved significantly, from 64% in 1976-1983 to 88% in 2004-2013. ARR over the whole period was 4% for all diagnostic groups, greatest for Hodgkin lymphomas (8%), ependymomas (6%), Burkitt's lymphomas (6%) and germ cell tumours (6%). Children treated in hospitals without specialised paediatric cancer centre for leukaemia (HR 12.9), lymphoma (HR 5.0) and neuroblastoma (HR 3.7) were at higher risk of death. In French-speaking Switzerland, risk of death was lower for lymphoma (HR 0.6), CNS tumours (HR 0.7) and neuroblastoma (HR 0.5). Children with migration background had a higher risk of death from all tumours except bone tumours. Childhood cancer survival significantly improved from 1976 to 2013, but there is room for further improvement. Survival rates varied by type of clinical treatment, language region and nationality. All paediatric cancer patients should be referred to a specialised paediatric cancer centre. Further research is needed to intervene and completely eliminate inequalities in survival. © 2016 UICC.

Effect of fibrinolysis inhibitors on survival time of irradiated rats

International Nuclear Information System (INIS)

Smok, W.

1988-01-01

The possibilities of alleviation of the gastrointestinal syndrome of acute radiation sickness by modification of haemorrhagic diathesis using EACA and traskolan were studied. A significant prolongation of the mean survival time was obtained in the irradiated rats treated with EACA. 7 tabs., 10 refs. (author)

Providing Survivable Real-Time Communication Service for Distributed Mission Critical Systems

National Research Council Canada - National Science Library

Zhao, Wei; Bettati, Riccardo; Vaidya, Nitin

2005-01-01

This document is the final report for Providing Survivable Real-Time Communication Service for Distributed Mission Critical Systems, a Texas A AND M project funded through the DARPA Fault Tolerant Networks Program...

Effect of a long-term high-protein diet on survival, obesity development, and gut microbiota in mice

DEFF Research Database (Denmark)

Kiilerich, Pia; Myrmel, Lene Secher; Fjære, Even

2016-01-01

Female C57BL/6J mice were fed a regular low-fat diet or high-fat diets combined with either high or low protein-to-sucrose ratios during their entire lifespan to examine the long-term effects on obesity development, gut microbiota, and survival. Intake of a high-fat diet with a low protein....../sucrose ratio precipitated obesity and reduced survival relative to mice fed a low-fat diet. By contrast, intake of a high-fat diet with a high protein/sucrose ratio attenuated lifelong weight gain and adipose tissue expansion, and survival was not significantly altered relative to low-fat-fed mice. Our...... findings support the notion that reduced survival in response to high-fat/high-sucrose feeding is linked to obesity development. Digital gene expression analyses, further validated by qPCR, demonstrated that the protein/sucrose ratio modulated global gene expression over time in liver and adipose tissue...

Results of surgical excision and evaluation of factors associated with survival time in dogs with lingual neoplasia: 97 cases (1995-2008).

Science.gov (United States)

Culp, William T N; Ehrhart, Nicole; Withrow, Stephen J; Rebhun, Robert B; Boston, Sarah; Buracco, Paolo; Reiter, Alexander M; Schallberger, Sandra P; Aldridge, Charles F; Kent, Michael S; Mayhew, Philipp D; Brown, Dorothy C

2013-05-15

To describe the clinical characteristics, treatments, outcomes, and factors associated with survival time in a cohort of dogs with lingual neoplasia that underwent surgical excision. Retrospective case series. Animals-97 client-owned dogs. Medical records of dogs with a lingual tumor examined between 1995 and 2008 were reviewed. Records were included if a lingual tumor was confirmed by histologic examination and surgical excision of the mass was attempted. Data were recorded and analyzed to identify prognostic factors. Clinical signs were mostly related to the oral cavity. For 93 dogs, marginal excision, subtotal glossectomy, and near-total glossectomy were performed in 35 (38%), 55 (59%), and 3 (3%), respectively. Surgery-related complications were rare, but 27 (28%) dogs had tumor recurrence. The most common histopathologic diagnoses for the 97 dogs were squamous cell carcinoma (31 [32%]) and malignant melanoma (29 [30%]). Eighteen (19%) dogs developed metastatic disease, and the overall median survival time was 483 days. Median survival time was 216 days for dogs with squamous cell carcinoma and 241 days for dogs with malignant melanoma. Dogs with lingual tumors ≥ 2 cm in diameter at diagnosis had a significantly shorter survival time than did dogs with tumors melanoma predominate. A thorough physical examination to identify lingual tumors at an early stage and surgical treatment after tumor identification are recommended because tumor size significantly affected survival time.

Impact of latency time on survival for adolescents and young adults with a second primary malignancy.

Science.gov (United States)

Goldfarb, Melanie; Rosenberg, Aaron S; Li, Qian; Keegan, Theresa H M

2018-03-15

The adverse impact of second primary malignancies (SPMs) on survival is substantial for adolescents and young adults (AYAs; ie, those 15-39 years old). No studies have evaluated whether the latency time between the first malignancy (the primary malignancy [PM]) and the SPM affects cancer-specific survival (CSS). A multivariate Cox proportional hazards regression with Surveillance, Epidemiology, and End Results data for 13 regions from 1992 to 2008 was used to ascertain whether the latency time (1-5 vs ≥ 6 years) to the development of an SPM affected the CSS and overall survival with respect to either the PM or SPM for AYAs with common SPMs. The majority of 1515 AYAs with an SPM had their PM diagnosed between the ages of 26 and 39 years (74.2%) and an SPM diagnosed within 1 to 5 years (72.9%) of the PM's diagnosis. Overall, AYAs that developed an SPM 1 to 5 years after the diagnosis (vs ≥ 6 years) had an increased risk of death from cancer (hazard ratio [HR], 2.52; 95% confidence interval [CI], 1.92-3.29) as well as any cause (HR, 2.60; 95% CI, 2.04-3.32). Specifically, for AYAs with an SPM that was leukemia or a colorectal, breast, or central nervous system malignancy, a shorter latency time (1-5 years) from their PM diagnosis was associated with an overall significantly increased risk of death (2.6-fold) from either their PM or that particular SPM. However, latency did not appear to affect the CSS with respect to either the PM or SPM for AYA patients with a lymphoma or sarcoma SPM. Most AYAs who develop an SPM do so within 1 to 5 years of their primary cancer diagnosis, and they have an increased risk of death from cancer in comparison with AYAs with an SPM developing after longer survivorship intervals. Cancer 2018;124:1260-8. © 2017 American Cancer Society. © 2017 American Cancer Society.

Probability of Survival Decision Aid (PSDA)

National Research Council Canada - National Science Library

Xu, Xiaojiang; Amin, Mitesh; Santee, William R

2008-01-01

A Probability of Survival Decision Aid (PSDA) is developed to predict survival time for hypothermia and dehydration during prolonged exposure at sea in both air and water for a wide range of environmental conditions...

Survival times of pre-1950 US women radium dial workers

International Nuclear Information System (INIS)

Stehney, A.F.

1994-01-01

Survival times of US women radium dial workers to the end of 1989 were examined by life table methods. Included were 1301 women rust employed before 1930 and 1242 first employed in 1930-1949. Expected numbers of deaths were estimated from age- and time-specific death rates for US white females. In the early group, 85 deaths from the well-known radium-induced cancers - bone sarcomas and head carcinomas - were observed, but only 724 deaths from aH other causes were observed vs 755 expected. Life shortening (±S.E.) of 1.8 ±0.5 y compared to the general population of US white females was calculated from the time distribution of all deaths in the pre-1930 group. In the 1930--1949 group, 350 deaths were observed vs 343 expected and no bone sarcomas or head carcinomas occurred. Among women who survived at least 2 y after rust measurement of body radium, a significant excess of observed vs expected deaths was found only for radium intakes greater than 1.85 MBq of 226 Ra + 228 Ra, and no trend of deaths or reduction of life expectancy was found with length of employment

Increasing survival time decreases the cost-effectiveness of using "test & treat'' to eliminate HIV epidemics.

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Wagner, Bradley G; Coburn, Brian J; Blower, Sally

2013-01-01

Treating HIV-infected individuals reduces their viral load, consequently increasing their survival time and decreasing their infectivity. It has been proposed that universal testing and treatment (i.e., universal "test & treat'') could lead to HIV elimination and would be extremely cost-effective. It is now being debated whether to use a universal "test & treat'' approach in the "real-world'' as a prevention strategy to control HIV epidemics. However current modeling predictions of the impact, and cost-effectiveness, of universal `"est & treat'' strategies are based on an unrealistically short survival time for treated individuals. Here we use mathematical modeling and a longer, more realistic, survival time. We model the potential impact of a universal "test & treat'' strategy in South Africa. Our results show that increasing the length of the survival time on treatment, although beneficial to individuals, reduces the probability of eliminating HIV and decreases the cost-effectiveness of using universal "test & treat'' strategies. Therefore our results show that individual-level benefits and public health benefits will conflict when using "test &treat'' strategies to reduce HIV transmission.

Temperature, larval diet, and density effects on development rate and survival of Aedes aegypti (Diptera: Culicidae.

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Jannelle Couret

Full Text Available Many environmental factors, biotic and abiotic interact to influence organismal development. Given the importance of Aedes aegypti as a vector of human pathogens including dengue and yellow fever, understanding the impact of environmental factors such as temperature, resource availability, and intraspecific competition during development is critical for population control purposes. Despite known associations between developmental traits and factors of diet and density, temperature has been considered the primary driver of development rate and survival. To determine the relative importance of these critical factors, wide gradients of conditions must be considered. We hypothesize that 1 diet and density, as well as temperature influence the variation in development rate and survival, 2 that these factors interact, and this interaction is also necessary to understand variation in developmental traits. Temperature, diet, density, and their two-way interactions are significant factors in explaining development rate variation of the larval stages of Ae. aegypti mosquitoes. These factors as well as two and three-way interactions are significantly associated with the development rate from hatch to emergence. Temperature, but not diet or density, significantly impacted juvenile mortality. Development time was heteroskedastic with the highest variation occurring at the extremes of diet and density conditions. All three factors significantly impacted survival curves of experimental larvae that died during development. Complex interactions may contribute to variation in development rate. To better predict variation in development rate and survival in Ae. aegypti, factors of resource availability and intraspecific density must be considered in addition, but never to the exclusion of temperature.

Survival time and effect of selected predictor variables on survival in owned pet cats seropositive for feline immunodeficiency and leukemia virus attending a referral clinic in northern Italy.

Science.gov (United States)

Spada, Eva; Perego, Roberta; Sgamma, Elena Assunta; Proverbio, Daniela

2018-02-01

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are among the most important feline infectious diseases worldwide. This retrospective study investigated survival times and effects of selected predictor factors on survival time in a population of owned pet cats in Northern Italy testing positive for the presence of FIV antibodies and FeLV antigen. One hundred and three retrovirus-seropositive cats, 53 FIV-seropositive cats, 40 FeLV-seropositive cats, and 10 FIV+FeLV-seropositive cats were included in the study. A population of 103 retrovirus-seronegative age and sex-matched cats was selected. Survival time was calculated and compared between retrovirus-seronegative, FIV, FeLV and FIV+FeLV-seropositive cats using Kaplan-Meier survival analysis. Cox proportional-hazards regression analysis was used to study the effect of selected predictor factors (male gender, peripheral blood cytopenia as reduced red blood cells - RBC- count, leukopenia, neutropenia and lymphopenia, hypercreatininemia and reduced albumin to globulin ratio) on survival time in retrovirus-seropositive populations. Median survival times for seronegative cats, FIV, FeLV and FIV+FeLV-seropositive cats were 3960, 2040, 714 and 77days, respectively. Compared to retrovirus-seronegative cats median survival time was significantly lower (P<0.000) in FeLV and FIV+FeLV-seropositive cats. Median survival time in FeLV and FIV+FeLV-seropositive cats was also significant lower (P<0.000) when compared to FIV-seropositive cats. Hazard ratio of death in FeLV and FIV+FeLV-seropositive cats being respectively 3.4 and 7.4 times higher, in comparison to seronegative cats and 2.3 and 4.8 times higher in FeLV and FIV+FeLV-seropositive cats as compared to FIV-seropositive cats. A Cox proportional-hazards regression analysis showed that FIV and FeLV-seropositive cats with reduced RBC counts at time of diagnosis of seropositivity had significantly shorter survival times when compared to FIV and Fe

Analyzing survival curves at a fixed point in time for paired and clustered right-censored data

Science.gov (United States)

Su, Pei-Fang; Chi, Yunchan; Lee, Chun-Yi; Shyr, Yu; Liao, Yi-De

2018-01-01

In clinical trials, information about certain time points may be of interest in making decisions about treatment effectiveness. Rather than comparing entire survival curves, researchers can focus on the comparison at fixed time points that may have a clinical utility for patients. For two independent samples of right-censored data, Klein et al. (2007) compared survival probabilities at a fixed time point by studying a number of tests based on some transformations of the Kaplan-Meier estimators of the survival function. However, to compare the survival probabilities at a fixed time point for paired right-censored data or clustered right-censored data, their approach would need to be modified. In this paper, we extend the statistics to accommodate the possible within-paired correlation and within-clustered correlation, respectively. We use simulation studies to present comparative results. Finally, we illustrate the implementation of these methods using two real data sets. PMID:29456280

Correlation between the CT manifestations and post-operative survival time in patients with thymic epithelial tumor

International Nuclear Information System (INIS)

Chen Juan; Tan Ye; Wang Xiangyang; Du Jun; Pan Jishu; Wei Jiahu

2011-01-01

Objective: To describe the CT manifestations of thymic epithelial tumor and explore the correlation between CT findings and post-operative tumor-related survival time. Methods: Ninety-one patients who underwent CT scan before operation were reviewed retrospectively. All cases had operation and were classified according to the WHO classification. The size, contour, shape, density and enhancement of the tumors on CT were assessed. Presence of mediastinal lymphadenopathy, great vessel invasion, metastasis to the lung or plural, myasthenia gravis (MG) were also analyzed. The survival rate was obtained using, the Kaplan-Meier method. The Cox model was applied to determine the factors affecting the tumor-related survivals. Chi square test was used to analyze the relationship between CT findings and WHO classification. Results: Two patients were excluded because of dying of myocardial infarction and colon cancer. The total 5-year survival rate was 84.3% (n=75). Eighty-nine patients had total 91 tumors. Tumors with diameter larger than 5 cm, lobular contour, heterogenous density, and presence of great vessel invasion, mediastinal lymphadenopathy, and metastasis were adverse factors which could significantly affect the survival time. Five-year survival rates of these factors were 72.7%, 77.3%, 76.7%, 73.8%, 30.0%, and 68.8%, respectively. Presence of MG was a favorable factor which also significantly affected the survival time (P 0.05). The result of the Cox multivariate analysis was consistent with that of the Log-rank test. For different WHO classification, there were significant different among the size or contour of the tumors, presence of great vessel invasion, mediastinal lymphadenopathy, and metastasis (χ 2 value were 6.598, 5.737, 18.307, 8.465, and 15.608, respectively P<0.05). Conclusions: CT findings may be served as predictors of clinical prognosis of the thymic epithelial tumors. Adverse factors for survival time are the size of the tumors and presence of

Does prehospital time affect survival of major trauma patients where there is no prehospital care?

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S B Dharap

2017-01-01

Full Text Available Background: Survival after major trauma is considered to be time dependent. Efficient prehospital care with rapid transport is the norm in developed countries, which is not available in many lower middle and low-income countries. The aim of this study was to assess the effect of prehospital time and primary treatment given on survival of major trauma patients in a setting without prehospital care. Materials and Methods: This prospective observational study was carried out in a university hospital in Mumbai, from January to December 2014. The hospital has a trauma service but no organized prehospital care or defined interhospital transfer protocols. All patients with life- and/or limb-threatening injuries were included in the study. Injury time and arrival time were noted and the interval was defined as “prehospital time” for the directly arriving patients and as “time to tertiary care” for those transferred. Primary outcome measure was in-hospital death (or discharge. Results: Of 1181 patients, 352 were admitted directly from the trauma scene and 829 were transferred from other hospitals. In-hospital mortality was associated with age, mechanism and mode of injury, shock, Glasgow Coma Score <9, Injury Severity Score ≥16, need for intubation, and ventilatory support on arrival; but neither with prehospital time nor with time to tertiary care. Transferred patients had a significantly higher mortality (odds ratio = 1.869, 95% confidence interval = 1.233–2.561, P = 0.005 despite fewer patients with severe injury. Two hundred and ninety-four (35% of these needed airway intervention while 108 (13% needed chest tube insertion on arrival to the trauma unit suggesting inadequate care at primary facility. Conclusion: Mortality is not associated with prehospital time but with transfers from primary care; probably due to deficient care. To improve survival after major trauma, enhancement of resources for resuscitation and capacity building of on

Application of accelerated failure time models for breast cancer patients' survival in Kurdistan Province of Iran.

Science.gov (United States)

Karimi, Asrin; Delpisheh, Ali; Sayehmiri, Kourosh

2016-01-01

Breast cancer is the most common cancer and the second common cause of cancer-induced mortalities in Iranian women. There has been a rapid development in hazard models and survival analysis in the last decade. The aim of this study was to evaluate the prognostic factors of overall survival (OS) in breast cancer patients using accelerated failure time models (AFT). This was a retrospective-analytic cohort study. About 313 women with a pathologically proven diagnosis of breast cancer who had been treated during a 7-year period (since January 2006 until March 2014) in Sanandaj City, Kurdistan Province of Iran were recruited. Performance among AFT was assessed using the goodness of fit methods. Discrimination among the exponential, Weibull, generalized gamma, log-logistic, and log-normal distributions was done using Akaik information criteria and maximum likelihood. The 5 years OS was 75% (95% CI = 74.57-75.43). The main results in terms of survival were found for the different categories of the clinical stage covariate, tumor metastasis, and relapse of cancer. Survival time in breast cancer patients without tumor metastasis and relapse were 4, 2-fold longer than other patients with metastasis and relapse, respectively. One of the most important undermining prognostic factors in breast cancer is metastasis; hence, knowledge of the mechanisms of metastasis is necessary to prevent it so occurrence and treatment of metastatic breast cancer and ultimately extend the lifetime of patients.

The importance of time interval to development of second tumor in metachronous bilateral wilms' tumor

International Nuclear Information System (INIS)

Paulino, Arnold C.; Thakkar, Bharat; Henderson, William G.

1997-01-01

Purpose: To determine whether the time interval to development of second tumor is a prognostic factor for overall survival in children with metachronous bilateral Wilms' tumor and to give a recommendation regarding screening of the contralateral kidney in patients with Wilms' tumor. Materials and Management: A literature search using MEDLINE was performed of manuscripts in the English language from 1950-1996 and identified 108 children with metachronous bilateral Wilms' tumor. Children were classified according to time interval to development of a contralateral Wilms' tumor ( 78 mos (2), 78 - < 84 mos (1), 84 - < 90 mos (0), 90 - < 96 mos (1), ≥ 96 mos (0). Analysis of overall survival in patients with a time interval of < 18 months and ≥ 18 months showed a 10 year survival of 39.6% and 55.2%, respectively (p = 0.024, log-rank test). Conclusions: Children with metachronous bilateral Wilms' tumor who develop a contralateral tumor at a time interval of ≥ 18 months from the initial Wilms' tumor had a better overall survival than children with a time interval of < 18 months. Screening by abdominal ultrasound of the contralateral kidney for more than 5 years after initial diagnosis of Wilms' tumor may not be necessary since 102/106 (96.2%) of children had a time interval to second tumor of < 60 months

Lessons from Cacti: How to Survive the Prickles of Life during Tough Times

Science.gov (United States)

Bigger, Alan S.; Bigger, Linda B.

2009-01-01

The saguaro cactus looked a little like humans, in different shapes and sizes. How on earth do they survive in a climate that seems so inhospitable? It is possible to learn lessons for life from a cactus, if one can only get beyond the thorns, and that these lessons will assist one to survive during tough or prickly times. These plants survive…

Effect of liquid nitrogen storage time on the survival and ...

African Journals Online (AJOL)

Investigations were undertaken on the effect of liquid nitrogen (LN) storage time on survival and regeneration of somatic embryos of cocoa (Theobroma cacao l.). Somatic embryos from different cocoa genotypes (AMAZ 3-2, AMAZ 10-1, AMAZ 12, SIAL 93, and IMC 14) at 15.45% moisture content were cryopreserved in LN ...

Effects of mercury on survival and development of the larval grass shrimp Palaemonetes vulgaris

Energy Technology Data Exchange (ETDEWEB)

Shealy, M.H. Jr.; Sandifer, P.A.

1975-11-10

Effects of 7 concentrations of mercury from 0.0 (control) to 0.056 ppM on survival and development of the larval grass shrimp Palaemonetes vulgaris (Say) were investigated. A concentration of 0.056 ppM Hg was toxic to all larvae within 24 h, but below a threshold level (less than or equal to 0.0056 ppM) no lethal effect occurred within 48 h. Feeding appeared to increase slightly the resistance of P. vulgaris larvae to mercury, and 48-h median tolerance limits for fed and unfed larvae were 0.0156 and 0.0100 ppM, respectively. Delayed effects of 48-h exposure to sublethal mercury concentrations which appeared in later post-exposure rearing of the larvae included reduced survival to the postlarval stage, delayed molting, extended development time, increased numbers of larval instars, and morphological deformities.

Median Survival Time of Endometrial Cancer Patients with Lymphovascular Invasion at the Hospital Universiti Sains Malaysia.

Science.gov (United States)

Asyikeen, Wan Adnan Wan Nor; Siti-Azrin, Ab Hamid; Jalil, Nur Asyilla Che; Zin, Anani Aila Mat; Othman, Nor Hayati

2016-11-01

Endometrial cancer is the most common gynaecologic malignancy among females worldwide. The purpose of this study was to determine the median survival time of endometrial cancer patients at the Hospital Universiti Sains Malaysia (USM). A list of 121 endometrial cancer cases registered at Hospital USM between 2000 until 2011 was retrospectively reviewed. The survival time of the endometrial cancer patients was estimated by Kaplan-Meier survival analysis. Log-rank tests were performed to compare the survival of the patients based on socio-demographics and clinical presentation. Only 108 patients, 87.0%, were included who were of Malay ethnicity. Previous history included menopause in 67.6% of patients and diabetes mellitus in 39.8% of patients; additionally, 63.4% of patients were nulliparous. Tumour staging was as follows: 24.5% stage I, 10.8% stage II, 26.5% stage III and 38.2% stage IV. The overall median survival time of the endometrial cancer patients was 70.20 months (95% confidence interval (CI): 51.79, 88.61). The significant factors were age, the presence of lymphovascular invasion and treatment received. The overall survival of endometrial cancer was low. A prospective study needs to be carried out to discover more effective and accurate tests for the early detection of endometrial cancer.

The time dependent association of adrenaline administration and survival from out-of-hospital cardiac arrest.

Science.gov (United States)

Ewy, Gordon A; Bobrow, Bentley J; Chikani, Vatsal; Sanders, Arthur B; Otto, Charles W; Spaite, Daniel W; Kern, Karl B

2015-11-01

Recommended for decades, the therapeutic value of adrenaline (epinephrine) in the resuscitation of patients with out-of-hospital cardiac arrest (OHCA) is controversial. To investigate the possible time-dependent outcomes associated with adrenaline administration by Emergency Medical Services personnel (EMS). A retrospective analysis of prospectively collected data from a near statewide cardiac resuscitation database between 1 January 2005 and 30 November 2013. Multivariable logistic regression was used to analyze the effect of the time interval between EMS dispatch and the initial dose of adrenaline on survival. The primary endpoints were survival to hospital discharge and favourable neurologic outcome. Data from 3469 patients with witnessed OHCA were analyzed. Their mean age was 66.3 years and 69% were male. An initially shockable rhythm was present in 41.8% of patients. Based on a multivariable logistic regression model with initial adrenaline administration time interval (AATI) from EMS dispatch as the covariate, survival was greatest when adrenaline was administered very early but decreased rapidly with increasing (AATI); odds ratio 0.94 (95% Confidence Interval (CI) 0.92-0.97). The AATI had no significant effect on good neurological outcome (OR=0.96, 95% CI=0.90-1.02). In patients with OHCA, survival to hospital discharge was greater in those treated early with adrenaline by EMS especially in the subset of patients with a shockable rhythm. However survival rapidly decreased with increasing adrenaline administration time intervals (AATI). Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

33 CFR 150.503 - What are the time interval requirements for maintenance on survival craft falls?

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What are the time interval requirements for maintenance on survival craft falls? 150.503 Section 150.503 Navigation and Navigable Waters... maintenance on survival craft falls? (a) Each fall used in a launching device for survival craft or rescue...

Time dependent ethnic convergence in colorectal cancer survival in hawaii

Directory of Open Access Journals (Sweden)

Hundahl Scott A

2003-02-01

Full Text Available Abstract Background Although colorectal cancer death rates have been declining, this trend is not consistent across all ethnic groups. Biological, environmental, behavioral and socioeconomic explanations exist, but the reason for this discrepancy remains inconclusive. We examined the hypothesis that improved cancer screening across all ethnic groups will reduce ethnic differences in colorectal cancer survival. Methods Through the Hawaii Tumor Registry 16,424 patients diagnosed with colorectal cancer were identified during the years 1960–2000. Cox regression analyses were performed for each of three cohorts stratified by ethnicity (Caucasian, Japanese, Hawaiian, Filipino, and Chinese. The models included stage of diagnosis, year of diagnosis, age, and sex as predictors of survival. Results Mortality rates improved significantly for all ethnic groups. Moreover, with the exception of Hawaiians, rates for all ethnic groups converged over time. Persistently lower survival for Hawaiians appeared linked with more cancer treatment. Conclusion Ethnic disparities in colorectal cancer mortality rates appear primarily the result of differential utilization of health care. If modern screening procedures can be provided equally to all ethnic groups, ethnic outcome differences can be virtually eliminated.

Timely disclosure of progress in long-term cancer survival: the boomerang method substantially improved estimates in a comparative study.

Science.gov (United States)

Brenner, Hermann; Jansen, Lina

2016-02-01

Monitoring cancer survival is a key task of cancer registries, but timely disclosure of progress in long-term survival remains a challenge. We introduce and evaluate a novel method, denoted "boomerang method," for deriving more up-to-date estimates of long-term survival. We applied three established methods (cohort, complete, and period analysis) and the boomerang method to derive up-to-date 10-year relative survival of patients diagnosed with common solid cancers and hematological malignancies in the United States. Using the Surveillance, Epidemiology and End Results 9 database, we compared the most up-to-date age-specific estimates that might have been obtained with the database including patients diagnosed up to 2001 with 10-year survival later observed for patients diagnosed in 1997-2001. For cancers with little or no increase in survival over time, the various estimates of 10-year relative survival potentially available by the end of 2001 were generally rather similar. For malignancies with strongly increasing survival over time, including breast and prostate cancer and all hematological malignancies, the boomerang method provided estimates that were closest to later observed 10-year relative survival in 23 of the 34 groups assessed. The boomerang method can substantially improve up-to-dateness of long-term cancer survival estimates in times of ongoing improvement in prognosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Palliative Sedation in Advanced Cancer Patients: Does it Shorten Survival Time? - A Systematic Review.

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Barathi, B; Chandra, Prabha S

2013-01-01

Patients with advanced cancer often suffer from multiple refractory symptoms in the terminal phase of their life. Palliative sedation is one of the few ways to relieve this refractory suffering. This systematic review investigated the effect of palliative sedation on survival time in terminally ill cancer patients. Six electronic databases were searched for both prospective and retrospective studies which evaluated the effect of palliative sedation on survival time. Only those studies which had a comparison group that did not receive palliative sedation were selected for the review. Abstracts of all retrieved studies were screened to include the most relevant studies and only studies which met inclusion criteria were selected. References of all retrieved studies were also screened for relevant studies. Selected studies were assessed for quality and data extraction was done using the structured data extraction form. Eleven studies including four prospective and seven retrospective studies were identified. Mean survival time (MST) was measured as the time from last admission until death. A careful analysis of the results of all the 11 studies indicated that MST of sedated and non-sedated group was not statistically different in any of the studies. This systematic review supports the fact that palliative sedation does not shorten survival in terminally ill cancer patients. However, this conclusion needs to be taken with consideration of the methodology, study design, and the population studied of the included studies in this review.

Palliative sedation in advanced cancer patients: Does it shorten survival time? - A systematic review

Directory of Open Access Journals (Sweden)

B Barathi

2013-01-01

Full Text Available Background: Patients with advanced cancer often suffer from multiple refractory symptoms in the terminal phase of their life. Palliative sedation is one of the few ways to relieve this refractory suffering. Objectives: This systematic review investigated the effect of palliative sedation on survival time in terminally ill cancer patients. Materials and Methods: Six electronic databases were searched for both prospective and retrospective studies which evaluated the effect of palliative sedation on survival time. Only those studies which had a comparison group that did not receive palliative sedation were selected for the review. Abstracts of all retrieved studies were screened to include the most relevant studies and only studies which met inclusion criteria were selected. References of all retrieved studies were also screened for relevant studies. Selected studies were assessed for quality and data extraction was done using the structured data extraction form. Results: Eleven studies including four prospective and seven retrospective studies were identified. Mean survival time (MST was measured as the time from last admission until death. A careful analysis of the results of all the 11 studies indicated that MST of sedated and non-sedated group was not statistically different in any of the studies. Conclusion: This systematic review supports the fact that palliative sedation does not shorten survival in terminally ill cancer patients. However, this conclusion needs to be taken with consideration of the methodology, study design, and the population studied of the included studies in this review.

Using Concurrent Cardiovascular Information to Augment Survival Time Data for Evaluating Orthostatic Tilt Test Performance

Science.gov (United States)

Feiveson, Alan H.; Fiedler, James; Lee, Stuart M. C.; Koslovsky, Matthew D.; Stenger, Michael B.; Platts, Steven H.

2018-01-01

Head-up tilt (HUT) tests often are used in research to measure orthostatic intolerance (OI) (inability to appropriately control blood pressure while upright) in clinical populations and otherwise healthy individuals after interventions. Post-space flight orthostatic intolerance is a well-known phenomenon, and countermeasures to its development has been an active area of research at NASA. In the NASA HUT protocol, subjects lie horizontally on an automatic tilt table for baseline measurements before being raised to 80deg head-up tilt for a defined period of time or until signs or symptoms of presyncope ensues (light-headedness, nausea, dizziness, sweating, weakness or fainting). Multiple measures are collected to evaluate the cardiovascular system's ability to respond appropriately to the orthostatic challenge. However if the intended duration of the HUT is short, the ability to detect changes in OI due to an intervention or its prevention by a countermeasure may be limited by a small number of failures to permit comparisons based on survival time alone. Thus, the time-trajectory of the cardiovascular data becomes an important additional source of information. In particular, we will show how various measures of trajectory variability can effectively augment survival analysis for the assessment of OI in a joint model when high censoring rates are present.

Survival and larval development of Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) on alternatives host

International Nuclear Information System (INIS)

Sa, Verissimo G.M. de; Boregas, Katia G.B.

2009-01-01

Two bioassays were conducted to evaluate the suitability of host plants of fall armyworm (FAW), Spodoptera frugiperda (J E Smith), in the Brazilian agro-ecosystem. Larval development and survival were analyzed by infesting leaves of maize, grain sorghum, Johnson grass, soybean, Brachiaria and tobacco with FAW newly hatched larvae in a no choice test. No significant differences of survival were observed among insects reared on different hosts, except for tobacco, where no survivors were recorded. Larvae fed on soybean and artificial diet grew larger than those fed on the other hosts. The heaviest pupa was observed from larva fed on artificial diet and the lighter from larva fed on Brachiaria grass. No significant differences were reported on larval development time on natural hosts, but it was longer for larvae reared on artificial diet. Three classes of larval development time were observed on maize, four on sorghum, Brachiaria and soybean, and five on artificial diet. Nearly 85% of FAW larvae completed development within 12 d on maize; 77% on grain sorghum, 80% on Johnson grass, 68% on Brachiaria and 83% on soybean within 14 d and 69% on artificial diet within 17 d. The host suitability to FAW decreases from maize to sorghum, soybean and Brachiaria. (author)

An Exploratory Study of Cooperative Survival: Strategic Adaptation to External Developments

Directory of Open Access Journals (Sweden)

Jasper Grashuis

2018-02-01

Full Text Available Farmer cooperatives have been portrayed in the literature as flawed and complex organizations with ambiguous objectives. However, research on the observed survival of farmer cooperatives in spite of their weaknesses and limitations is scarce, in part because academic attention to cooperative performance has been static and introspective. Using evidence collected from case studies and print media publications, this paper contributes to the literature with a qualitative study of farmer cooperatives which spurred survival and longevity by means of strategic adaptation in response to four current developments in the external environment: industry consolidation, consumer segmentation, price volatility, and policy change. The qualitative study concludes farmer cooperatives in general respond to such developments by means of organizational growth. Common strategies are vertical integration, geographic expansion, and portfolio diversification. While survival and longevity are promoted in theory, strategic adaptation also often facilitates the pursuit of investor-oriented as opposed to user-oriented objectives. In some scenarios, member ownership and control may become burdensome to the business and prompt conversion to another structure if further adaptation to internal and external developments is unsuccessful. More research is therefore needed to explore the dynamic and variable impact of strategy on cooperative survival.

Survivable architectures for time and wavelength division multiplexed passive optical networks

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Wong, Elaine

2014-08-01

The increased network reach and customer base of next-generation time and wavelength division multiplexed PON (TWDM-PONs) have necessitated rapid fault detection and subsequent restoration of services to its users. However, direct application of existing solutions for conventional PONs to TWDM-PONs is unsuitable as these schemes rely on the loss of signal (LOS) of upstream transmissions to trigger protection switching. As TWDM-PONs are required to potentially use sleep/doze mode optical network units (ONU), the loss of upstream transmission from a sleeping or dozing ONU could erroneously trigger protection switching. Further, TWDM-PONs require its monitoring modules for fiber/device fault detection to be more sensitive than those typically deployed in conventional PONs. To address the above issues, three survivable architectures that are compliant with TWDM-PON specifications are presented in this work. These architectures combine rapid detection and protection switching against multipoint failure, and most importantly do not rely on upstream transmissions for LOS activation. Survivability analyses as well as evaluations of the additional costs incurred to achieve survivability are performed and compared to the unprotected TWDM-PON. Network parameters that impact the maximum achievable network reach, maximum split ratio, connection availability, fault impact, and the incremental reliability costs for each proposed survivable architecture are highlighted.

An approach to the drone fleet survivability assessment based on a stochastic continues-time model

Science.gov (United States)

Kharchenko, Vyacheslav; Fesenko, Herman; Doukas, Nikos

2017-09-01

An approach and the algorithm to the drone fleet survivability assessment based on a stochastic continues-time model are proposed. The input data are the number of the drones, the drone fleet redundancy coefficient, the drone stability and restoration rate, the limit deviation from the norms of the drone fleet recovery, the drone fleet operational availability coefficient, the probability of the drone failure-free operation, time needed for performing the required tasks by the drone fleet. The ways for improving the recoverable drone fleet survivability taking into account amazing factors of system accident are suggested. Dependencies of the drone fleet survivability rate both on the drone stability and the number of the drones are analysed.

Survival Times of Meter-Sized Rock Boulders on the Surface of Airless Bodies

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Basilevsky, A. T.; Head, J. W.; Horz, F.; Ramsley, K.

2015-01-01

This study considers the survival times of meter-sized rock boulders on the surfaces of several airless bodies. As the starting point, we employ estimates of the survival times of such boulders on the surface of the Moon by[1], then discuss the role of destruction due to day-night temperature cycling, consider the meteorite bombardment environment on the considered bodies in terms of projectile flux and velocities and finally estimate the survival times. Survival times of meter-sized rocks on lunar surface: The survival times of hand specimen-sized rocks exposed to the lunar surface environment were estimated based on experiments modeling the destruction of rocks by meteorite impacts, combined with measurements of the lunar surface meteorite flux, (e.g.,[2]). For estimations of the survival times of meter-sized lunar boulders, [1] suggested a different approach based on analysis of the spatial density of boulders on the rims of small lunar craters of known absolute age. It was found that for a few million years, only a small fraction of the boulders ejected by cratering process are destroyed, for several tens of million years approx.50% are destroyed, and for 200-300 Ma, 90 to 99% are destroyed. Following [2] and other works, [1] considered that the rocks are mostly destroyed by meteorite impacts. Destruction of rocks by thermal-stress. However, high diurnal temperature variations on the surface of the Moon and other airless bodies imply that thermal stresses may also be a cause of surface rock destruction. Delbo et al. [3] interpreted the observed presence of fine debris on the surface of small asteroids as due to thermal surface cycling. They stated that because of the very low gravity on the surface of these bodies, ejecta from meteorite impacts should leave the body, so formation there of fine debris has to be due to thermal cycling. Based on experiments on heating-cooling of cm-scale pieces of ordinary and carbonaceous chondrites and theoretical modeling of

A comparison of the conditional inference survival forest model to random survival forests based on a simulation study as well as on two applications with time-to-event data.

Science.gov (United States)

Nasejje, Justine B; Mwambi, Henry; Dheda, Keertan; Lesosky, Maia

2017-07-28

Random survival forest (RSF) models have been identified as alternative methods to the Cox proportional hazards model in analysing time-to-event data. These methods, however, have been criticised for the bias that results from favouring covariates with many split-points and hence conditional inference forests for time-to-event data have been suggested. Conditional inference forests (CIF) are known to correct the bias in RSF models by separating the procedure for the best covariate to split on from that of the best split point search for the selected covariate. In this study, we compare the random survival forest model to the conditional inference model (CIF) using twenty-two simulated time-to-event datasets. We also analysed two real time-to-event datasets. The first dataset is based on the survival of children under-five years of age in Uganda and it consists of categorical covariates with most of them having more than two levels (many split-points). The second dataset is based on the survival of patients with extremely drug resistant tuberculosis (XDR TB) which consists of mainly categorical covariates with two levels (few split-points). The study findings indicate that the conditional inference forest model is superior to random survival forest models in analysing time-to-event data that consists of covariates with many split-points based on the values of the bootstrap cross-validated estimates for integrated Brier scores. However, conditional inference forests perform comparably similar to random survival forests models in analysing time-to-event data consisting of covariates with fewer split-points. Although survival forests are promising methods in analysing time-to-event data, it is important to identify the best forest model for analysis based on the nature of covariates of the dataset in question.

A comparison of the conditional inference survival forest model to random survival forests based on a simulation study as well as on two applications with time-to-event data

Directory of Open Access Journals (Sweden)

Justine B. Nasejje

2017-07-01

Full Text Available Abstract Background Random survival forest (RSF models have been identified as alternative methods to the Cox proportional hazards model in analysing time-to-event data. These methods, however, have been criticised for the bias that results from favouring covariates with many split-points and hence conditional inference forests for time-to-event data have been suggested. Conditional inference forests (CIF are known to correct the bias in RSF models by separating the procedure for the best covariate to split on from that of the best split point search for the selected covariate. Methods In this study, we compare the random survival forest model to the conditional inference model (CIF using twenty-two simulated time-to-event datasets. We also analysed two real time-to-event datasets. The first dataset is based on the survival of children under-five years of age in Uganda and it consists of categorical covariates with most of them having more than two levels (many split-points. The second dataset is based on the survival of patients with extremely drug resistant tuberculosis (XDR TB which consists of mainly categorical covariates with two levels (few split-points. Results The study findings indicate that the conditional inference forest model is superior to random survival forest models in analysing time-to-event data that consists of covariates with many split-points based on the values of the bootstrap cross-validated estimates for integrated Brier scores. However, conditional inference forests perform comparably similar to random survival forests models in analysing time-to-event data consisting of covariates with fewer split-points. Conclusion Although survival forests are promising methods in analysing time-to-event data, it is important to identify the best forest model for analysis based on the nature of covariates of the dataset in question.

Religious women's groups help promote child survival and development.

Science.gov (United States)

Munir, L Z

1989-07-01

Indonesia faces the 2 major problems of high infant mortality and high child mortality at present. To improve the situation, the government urges the participation of all community members, especially those already organized in the nongovernmental organizations (NGOs). Because religion has a strong influence on people's daily lives in Indonesia, a special project called the Child Survival Project was established in 1986 as a joint undertaking of the government and UNICEF. Initially 12 religious NGOs (8 Islamic, 1 Hindu, 1 Protestant, and 2 Catholic) were involved as implementing agencies. The majority of members of these NGOs are women. The strategy used has been to establish, in cooperation with the 12 NGOs, a communication network through which child survival messages would be disseminated to help generate increased use of Posyandu services, especially immunization, oral rehydration therapy, and growth monitoring. Messages are incorporated into the normal activities of these religious groups, such as Al-Quran reading classes, Sunday schools, and Bible classes. In addition, guidelines for a reporting and feedback system have been prepared for use at village, subdistrict, district, and provincial levels for project monitoring. Religious women's NGOs can serve with their specific characteristics can serve as motivators, facilitators, and catalysts of child survival and development programs for their community target groups. NGOs should be considered as partners of the government in mobilizing the community to achieve a common goal. All endeavors undertaken so far in relation to child survival and development are expected to be institutionalized.

Enhancement of radiation effect on mouse intestinal crypt survival by timing of 5-fluorouracil administration

International Nuclear Information System (INIS)

Ho, E.; Coffey, C.; Maruyama, Y.

1977-01-01

There is a marked dependence of mouse crypt survival on the sequence of combined drug-radiation treatment and on the time lapse between irradiation and drug administration. When 5-fluorouracil is administered 6 hours after irradiation or later (up to 18 hours postirradiation), crypt survival drops significantly

Integration of RNA-Seq and RPPA data for survival time prediction in cancer patients.

Science.gov (United States)

Isik, Zerrin; Ercan, Muserref Ece

2017-10-01

Integration of several types of patient data in a computational framework can accelerate the identification of more reliable biomarkers, especially for prognostic purposes. This study aims to identify biomarkers that can successfully predict the potential survival time of a cancer patient by integrating the transcriptomic (RNA-Seq), proteomic (RPPA), and protein-protein interaction (PPI) data. The proposed method -RPBioNet- employs a random walk-based algorithm that works on a PPI network to identify a limited number of protein biomarkers. Later, the method uses gene expression measurements of the selected biomarkers to train a classifier for the survival time prediction of patients. RPBioNet was applied to classify kidney renal clear cell carcinoma (KIRC), glioblastoma multiforme (GBM), and lung squamous cell carcinoma (LUSC) patients based on their survival time classes (long- or short-term). The RPBioNet method correctly identified the survival time classes of patients with between 66% and 78% average accuracy for three data sets. RPBioNet operates with only 20 to 50 biomarkers and can achieve on average 6% higher accuracy compared to the closest alternative method, which uses only RNA-Seq data in the biomarker selection. Further analysis of the most predictive biomarkers highlighted genes that are common for both cancer types, as they may be driver proteins responsible for cancer progression. The novelty of this study is the integration of a PPI network with mRNA and protein expression data to identify more accurate prognostic biomarkers that can be used for clinical purposes in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Flow cytometric and radioisotopic determinations of platelet survival time in normal cats and feline leukemia virus-infected cats

International Nuclear Information System (INIS)

Jacobs, R.M.; Boyce, J.T.; Kociba, G.J.

1986-01-01

This study demonstrates the potential usefulness of a flow cytometric technique to measure platelet survival time in cats utilizing autologous platelets labeled in vitro with fluorescein isothiocyanate (FITC). When compared with a 51Cr method, no significant differences in estimated survival times were found. Both the 51Cr and FITC-labeling procedures induced similar changes in platelet shape and collagen-induced aggregation. Platelets labeled with FITC had significantly greater volumes compared with those of glutaraldehyde-fixed platelets. These changes were primarily related to the platelet centrifugation and washing procedures rather than the labels themselves. This novel technique potentially has wide applicability to cell circulation time studies as flow cytometry equipment becomes more readily available. Problems with the technique are discussed. In a preliminary study of the platelet survival time in feline leukemia virus (FeLV)-infected cats, two of three cats had significantly reduced survival times using both flow cytometric and radioisotopic methods. These data suggest increased platelet turnover in FeLV-infected cats

Flow cytometric and radioisotopic determinations of platelet survival time in normal cats and feline leukemia virus-infected cats

Energy Technology Data Exchange (ETDEWEB)

Jacobs, R.M.; Boyce, J.T.; Kociba, G.J.

1986-01-01

This study demonstrates the potential usefulness of a flow cytometric technique to measure platelet survival time in cats utilizing autologous platelets labeled in vitro with fluorescein isothiocyanate (FITC). When compared with a 51Cr method, no significant differences in estimated survival times were found. Both the 51Cr and FITC-labeling procedures induced similar changes in platelet shape and collagen-induced aggregation. Platelets labeled with FITC had significantly greater volumes compared with those of glutaraldehyde-fixed platelets. These changes were primarily related to the platelet centrifugation and washing procedures rather than the labels themselves. This novel technique potentially has wide applicability to cell circulation time studies as flow cytometry equipment becomes more readily available. Problems with the technique are discussed. In a preliminary study of the platelet survival time in feline leukemia virus (FeLV)-infected cats, two of three cats had significantly reduced survival times using both flow cytometric and radioisotopic methods. These data suggest increased platelet turnover in FeLV-infected cats.

Oncomiracidial development, survival and swimming behaviour of the monogenean Sparicotyle chrysophrii (Van Beneden and Hesse, 1863)

Czech Academy of Sciences Publication Activity Database

Repulles-Albelda, A.; Holzer, Astrid S.; Raga, J. A.; Montero, F. E.

338-341, MAR 29 (2012), s. 47-55 ISSN 0044-8486 Institutional research plan: CEZ:AV0Z60220518 Keywords : Sparicotyle chrysophrii * Sparus aurata * Polyopisthocotylea * Oncomiracidial development * Hatching * Survival time Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.009, year: 2012 http://www.sciencedirect.com/science/article/pii/S0044848612000646

Ensemble survival tree models to reveal pairwise interactions of variables with time-to-events outcomes in low-dimensional setting

Science.gov (United States)

Dazard, Jean-Eudes; Ishwaran, Hemant; Mehlotra, Rajeev; Weinberg, Aaron; Zimmerman, Peter

2018-01-01

Unraveling interactions among variables such as genetic, clinical, demographic and environmental factors is essential to understand the development of common and complex diseases. To increase the power to detect such variables interactions associated with clinical time-to-events outcomes, we borrowed established concepts from random survival forest (RSF) models. We introduce a novel RSF-based pairwise interaction estimator and derive a randomization method with bootstrap confidence intervals for inferring interaction significance. Using various linear and nonlinear time-to-events survival models in simulation studies, we first show the efficiency of our approach: true pairwise interaction-effects between variables are uncovered, while they may not be accompanied with their corresponding main-effects, and may not be detected by standard semi-parametric regression modeling and test statistics used in survival analysis. Moreover, using a RSF-based cross-validation scheme for generating prediction estimators, we show that informative predictors may be inferred. We applied our approach to an HIV cohort study recording key host gene polymorphisms and their association with HIV change of tropism or AIDS progression. Altogether, this shows how linear or nonlinear pairwise statistical interactions of variables may be efficiently detected with a predictive value in observational studies with time-to-event outcomes. PMID:29453930

Examining the Influence of Campus Climate on Students' Time to Degree: A Multilevel Discrete-Time Survival Analysis

Science.gov (United States)

Zhou, Ji; Castellanos, Michelle

2013-01-01

Utilizing longitudinal data of 3477 students from 28 institutions, we examine the effects of structural diversity and quality of interracial relation on students' persistence towards graduation within six years. We utilize multilevel discrete-time survival analysis to account for the longitudinal persistence patterns as well as the nested…

An exploratory discrete-time multilevel analysis of the effect of social support on the survival of elderly people in China

Science.gov (United States)

Feng, Zhixin; Jones, Kelvyn; Wang, Wenfei Winnie

2015-01-01

This study undertakes a survival analysis of elderly persons in China using Chinese Longitudinal Healthy Longevity Survey 2002–2008. Employing discrete-time multilevel models, we explored the effect of social support on the survival of elderly people in China. This study focuses on objective (living arrangements and received support) and subjective activities (perceived support) of social support, finding that the effect of different activities of social support on the survival of elderly people varies according to the availability of different support resources. Specifically, living with a spouse, financial independence, perceiving care support from any resource is associated with higher survival rates for elderly people. Separate analysis focusing on urban elderly and rural elderly revealed broadly similar results. There is a larger difference between those perceiving care support from family or social service and not perceiving care support in urban areas comparing to those in rural areas. Those who cannot pay medical expenses are the least likely to survive. The higher level of economic development in province has no significant effect on the survival of elderly people for the whole sample model and the elderly people in urban areas; however, there is a negative influence on the survival of the rural elderly people. PMID:25703671

Multiparametric analysis of magnetic resonance images for glioma grading and patient survival time prediction

International Nuclear Information System (INIS)

Garzon, Benjamin; Emblem, Kyrre E.; Mouridsen, Kim; Nedregaard, Baard; Due-Toennessen, Paulina; Nome, Terje; Hald, John K.; Bjoernerud, Atle; Haaberg, Asta K.; Kvinnsland, Yngve

2011-01-01

Background. A systematic comparison of magnetic resonance imaging (MRI) options for glioma diagnosis is lacking. Purpose. To investigate multiple MR-derived image features with respect to diagnostic accuracy in tumor grading and survival prediction in glioma patients. Material and Methods. T1 pre- and post-contrast, T2 and dynamic susceptibility contrast scans of 74 glioma patients with histologically confirmed grade were acquired. For each patient, a set of statistical features was obtained from the parametric maps derived from the original images, in a region-of-interest encompassing the tumor volume. A forward stepwise selection procedure was used to find the best combinations of features for grade prediction with a cross-validated logistic model and survival time prediction with a cox proportional-hazards regression. Results. Presence/absence of enhancement paired with kurtosis of the FM (first moment of the first-pass curve) was the feature combination that best predicted tumor grade (grade II vs. grade III-IV; median AUC 0.96), with the main contribution being due to the first of the features. A lower predictive value (median AUC = 0.82) was obtained when grade IV tumors were excluded. Presence/absence of enhancement alone was the best predictor for survival time, and the regression was significant (P < 0.0001). Conclusion. Presence/absence of enhancement, reflecting transendothelial leakage, was the feature with highest predictive value for grade and survival time in glioma patients

Multiparametric analysis of magnetic resonance images for glioma grading and patient survival time prediction

Energy Technology Data Exchange (ETDEWEB)

Garzon, Benjamin (Dept. of Circulation and Medical Imaging, NTNU, Trondheim (Norway)), email: benjamin.garzon@ntnu.no; Emblem, Kyrre E. (The Interventional Center, Rikshospitalet, Oslo Univ. Hospital, Oslo (Norway); Dept. of Radiology, MGH-HST AA Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston (United States)); Mouridsen, Kim (Center of Functionally Integrative Neuroscience, Aarhus Univ., Aarhus (Denmark)); Nedregaard, Baard; Due-Toennessen, Paulina; Nome, Terje; Hald, John K. (Dept. of Radiology and Nuclear Medicine, Rikshospitalet, Oslo Univ. Hospital, Oslo (Norway)); Bjoernerud, Atle (The Interventional Center, Rikshospitalet, Oslo Univ. Hospital, Oslo (Norway)); Haaberg, Asta K. (Dept. of Circulation and Medical Imaging, NTNU, Trondheim (Norway); Dept. of Medical Imaging, St Olav' s Hospital, Trondheim (Norway)); Kvinnsland, Yngve (NordicImagingLab, Bergen (Norway))

2011-11-15

Background. A systematic comparison of magnetic resonance imaging (MRI) options for glioma diagnosis is lacking. Purpose. To investigate multiple MR-derived image features with respect to diagnostic accuracy in tumor grading and survival prediction in glioma patients. Material and Methods. T1 pre- and post-contrast, T2 and dynamic susceptibility contrast scans of 74 glioma patients with histologically confirmed grade were acquired. For each patient, a set of statistical features was obtained from the parametric maps derived from the original images, in a region-of-interest encompassing the tumor volume. A forward stepwise selection procedure was used to find the best combinations of features for grade prediction with a cross-validated logistic model and survival time prediction with a cox proportional-hazards regression. Results. Presence/absence of enhancement paired with kurtosis of the FM (first moment of the first-pass curve) was the feature combination that best predicted tumor grade (grade II vs. grade III-IV; median AUC 0.96), with the main contribution being due to the first of the features. A lower predictive value (median AUC = 0.82) was obtained when grade IV tumors were excluded. Presence/absence of enhancement alone was the best predictor for survival time, and the regression was significant (P < 0.0001). Conclusion. Presence/absence of enhancement, reflecting transendothelial leakage, was the feature with highest predictive value for grade and survival time in glioma patients

Time to treatment as a quality metric in lung cancer: Staging studies, time to treatment, and patient survival

International Nuclear Information System (INIS)

Gomez, Daniel R.; Liao, Kai-Ping; Swisher, Stephen G.; Blumenschein, George R.; Erasmus, Jeremy J.; Buchholz, Thomas A.; Giordano, Sharon H.; Smith, Benjamin D.

2015-01-01

Purpose: Prompt staging and treatment are crucial for non-small cell lung cancer (NSCLC). We determined if predictors of treatment delay after diagnosis were associated with prognosis. Materials and methods: Medicare claims from 28,732 patients diagnosed with NSCLC in 2004–2007 were used to establish the diagnosis-to-treatment interval (ideally ⩽35 days) and identify staging studies during that interval. Factors associated with delay were identified with multivariate logistic regression, and associations between delay and survival by stage were tested with Cox proportional hazard regression. Results: Median diagnosis-to-treatment interval was 27 days. Receipt of PET was associated with delays (57.4% of patients with PET delayed [n = 6646/11,583] versus 22.8% of those without [n = 3908/17,149]; adjusted OR = 4.48, 95% CI 4.23–4.74, p < 0.001). Median diagnosis-to-PET interval was 15 days; PET-to-clinic, 5 days; and clinic-to-treatment, 12 days. Diagnosis-to-treatment intervals <35 days were associated with improved survival for patients with localized disease and those with distant disease surviving ⩾1 year but not for patients with distant disease surviving <1 year. Conclusion: Delays between diagnosing and treating NSCLC are common and associated with use of PET for staging. Reducing time to treatment may improve survival for patients with manageable disease at diagnosis

Evaluation of serum biochemical marker concentrations and survival time in dogs with protein-losing enteropathy.

Science.gov (United States)

Equilino, Mirjam; Théodoloz, Vincent; Gorgas, Daniela; Doherr, Marcus G; Heilmann, Romy M; Suchodolski, Jan S; Steiner, Jörg M; Burgener Dvm, Iwan A

2015-01-01

To evaluate serum concentrations of biochemical markers and survival time in dogs with protein-losing enteropathy (PLE). Prospective study. 29 dogs with PLE and 18 dogs with food-responsive diarrhea (FRD). Data regarding serum concentrations of various biochemical markers at the initial evaluation were available for 18 of the 29 dogs with PLE and compared with findings for dogs with FRD. Correlations between biochemical marker concentrations and survival time (interval between time of initial evaluation and death or euthanasia) for dogs with PLE were evaluated. Serum C-reactive protein concentration was high in 13 of 18 dogs with PLE and in 2 of 18 dogs with FRD. Serum concentration of canine pancreatic lipase immunoreactivity was high in 3 dogs with PLE but within the reference interval in all dogs with FRD. Serum α1-proteinase inhibitor concentration was less than the lower reference limit in 9 dogs with PLE and 1 dog with FRD. Compared with findings in dogs with FRD, values of those 3 variables in dogs with PLE were significantly different. Serum calprotectin (measured by radioimmunoassay and ELISA) and S100A12 concentrations were high but did not differ significantly between groups. Seventeen of the 29 dogs with PLE were euthanized owing to this disease; median survival time was 67 days (range, 2 to 2,551 days). Serum C-reactive protein, canine pancreatic lipase immunoreactivity, and α1-proteinase inhibitor concentrations differed significantly between dogs with PLE and FRD. Most initial biomarker concentrations were not predictive of survival time in dogs with PLE.

Factors associated with supermarket and convenience store closure: a discrete time spatial survival modelling approach.

Science.gov (United States)

Warren, Joshua L; Gordon-Larsen, Penny

2018-06-01

While there is a literature on the distribution of food stores across geographic and social space, much of this research uses cross-sectional data. Analyses attempting to understand whether the availability of stores across neighborhoods is associated with diet and/or health outcomes are limited by a lack of understanding of factors that shape the emergence of new stores and the closure of others. We used quarterly data on supermarket and convenience store locations spanning seven years (2006-2012) and tract-level census data in four US cities: Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota; San Francisco, California. A spatial discrete-time survival model was used to identify factors associated with an earlier and/or later closure time of a store. Sales volume was typically the strongest indicator of store survival. We identified heterogeneity in the association between tract-level poverty and racial composition with respect to store survival. Stores in high poverty, non-White tracts were often at a disadvantage in terms of survival length. The observed patterns of store survival varied by some of the same neighborhood sociodemographic factors associated with lifestyle and health outcomes, which could lead to confusion in interpretation in studies of the estimated effects of introduction of food stores into neighborhoods on health.

Atg5 Is Essential for the Development and Survival of Innate Lymphocytes

Directory of Open Access Journals (Sweden)

Timothy E. O’Sullivan

2016-05-01

Full Text Available Autophagy is an essential cellular survival mechanism that is required for adaptive lymphocyte development; however, its role in innate lymphoid cell (ILC development remains unknown. Furthermore, the conditions that promote lymphocyte autophagy during homeostasis are poorly understood. Here, we demonstrate that Atg5, an essential component of the autophagy machinery, is required for the development of mature natural killer (NK cells and group 1, 2, and 3 innate ILCs. Although inducible ablation of Atg5 was dispensable for the homeostasis of lymphocyte precursors and mature lymphocytes in lymphoreplete mice, we found that autophagy is induced in both adaptive and innate lymphocytes during homeostatic proliferation in lymphopenic hosts to promote their survival by limiting cell-intrinsic apoptosis. Induction of autophagy through metformin treatment following homeostatic proliferation increased lymphocyte numbers through an Atg5-dependent mechanism. These findings highlight the essential role for autophagy in ILC development and lymphocyte survival during lymphopenia.

Association of the Timing of Pregnancy With Survival in Women With Breast Cancer

Science.gov (United States)

Iqbal, Javaid; Amir, Eitan; Rochon, Paula A.; Giannakeas, Vasily; Sun, Ping

2017-01-01

Importance Increasing numbers of women experience pregnancy around the time of, or after, a diagnosis of breast cancer. Understanding the effect of pregnancy on survival in women with breast cancer will help in the counseling and treatment of these women. Objective To compare the overall survival of women diagnosed with breast cancer during pregnancy or in the postpartum period with that of women who had breast cancer but did not become pregnant. Design, Setting, and Participants This population-based, retrospective cohort study linked health administrative databases in Ontario, Canada, comprising 7553 women aged 20 to 45 years at the time of diagnosis with invasive breast cancer, from January 1, 2003, to December 31, 2014. Exposures Any pregnancy in the period from 5 years before, until 5 years after, the index date of the diagnosis of breast cancer. Women were classified into the following 4 exposure groups: no pregnancy (the referent), pregnancy before breast cancer, pregnancy-associated breast cancer, and pregnancy following breast cancer. Main Outcomes and Measures Five-year actuarial survival rates for all exposure groups, age-adjusted and multivariable hazard ratios [HRs] of pregnancy for overall survival for all exposure groups, and time-dependent hazard ratios for women with pregnancy following breast cancer. Results Among the 7553 women in the study (mean age at diagnosis, 39.1 years; median, 40 years; range, 20-44 years) the 5-year actuarial survival rate was 87.5% (95% CI, 86.5%-88.4%) for women with no pregnancy, 85.3% (95% CI, 82.8%-87.8%) for women with pregnancy before breast cancer (age-adjusted hazard ratio, 1.03; 95% CI, 0.85-1.27; P = .73), and 82.1% (95% CI, 78.3%-85.9%) for women with pregnancy-associated breast cancer (age-adjusted hazard ratio, 1.18; 95% CI, 0.91-1.53; P = .20). The 5-year actuarial survival rate was 96.7% (95% CI, 94.1%-99.3%) for women who had pregnancy 6 months or more after diagnosis of breast cancer, vs 87

Survival analysis using S analysis of time-to-event data

CERN Document Server

Tableman, Mara

2003-01-01

Survival Analysis Using S: Analysis of Time-to-Event Data is designed as a text for a one-semester or one-quarter course in survival analysis for upper-level or graduate students in statistics, biostatistics, and epidemiology. Prerequisites are a standard pre-calculus first course in probability and statistics, and a course in applied linear regression models. No prior knowledge of S or R is assumed. A wide choice of exercises is included, some intended for more advanced students with a first course in mathematical statistics. The authors emphasize parametric log-linear models, while also detailing nonparametric procedures along with model building and data diagnostics. Medical and public health researchers will find the discussion of cut point analysis with bootstrap validation, competing risks and the cumulative incidence estimator, and the analysis of left-truncated and right-censored data invaluable. The bootstrap procedure checks robustness of cut point analysis and determines cut point(s). In a chapter ...

Democratic survival in Latin America (1945-2005

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Aníbal PÉREZ-LIÑÁN

2014-12-01

Full Text Available Why do democracies survive or break down? In this paper, it returns to this classic question with an empirical focus on Latin America from 1945 to 2005. The argument deviates from the quantitative literature and a good part of the qualitative literature on democratic survival and breakdown. It is argued that structural variables such as the level of development and inequalities have not shaped prospects for democratic survival in Latin America. Nor, contrary to findings in some of the literature, has economic performance affected the survival of competitive regimes. Instead, it is focused on the regional political environment and on actors’ normative preferences about democracy and dictatorship and their policy radicalism or moderation. It is argued that 1 a higher level of development did not increase the likelihood of democratic survival in Latin America over this long time; 2 if actors have a normative preference for democracy, it is more likely to survive; and 3 policy moderation facilitates democratic survival.

The M1 form of tumor-associated macrophages in non-small cell lung cancer is positively associated with survival time

International Nuclear Information System (INIS)

Ma, Junliang; Liu, Lunxu; Che, Guowei; Yu, Nanbin; Dai, Fuqiang; You, Zongbing

2010-01-01

Tumor-associated macrophages (TAMs) play an important role in growth, progression and metastasis of tumors. In non-small cell lung cancer (NSCLC), TAMs' anti-tumor or pro-tumor role is not determined. Macrophages are polarized into M1 (with anti-tumor function) and M2 (with pro-tumor function) forms. This study was conducted to determine whether the M1 and M2 macrophage densities in NSCLC are associated with patient's survival time. Fifty patients with an average of 1-year survival (short survival group) and 50 patients with an average of 5-year survival (long survival group) were included in this retrospective study. Paraffin-embedded NSCLC specimens and their clinicopathological data including up to 8-year follow-up information were used. Immunohistochemical double-staining of CD68/HLA-DR (markers for M1 macrophages) and CD68/CD163 (markers for M2 macrophages) was performed and evaluated in a blinded fashion. The M1 and M2 macrophage densities in the tumor islets, stroma, or islets and stroma were determined using computer-aided microscopy. Correlation of the macrophage densities and patient's survival time was analyzed using the Statistical Package for the Social Sciences. Approximately 70% of TAMs were M2 macrophages and the remaining 30% were M1 macrophages in NSCLC. The M2 macrophage densities (approximately 78 to 113 per mm 2 ) in the tumor islets, stroma, or islets and stroma were not significantly different between the long survival and short survival groups. The M1 macrophage densities in the tumor islets (approximately 70/mm 2 ) and stroma (approximately 34/mm 2 ) of the long survival group were significantly higher than the M1 macrophage densities in the tumor islets (approximately 7/mm 2 ) and stroma (13/mm 2 ) of the short survival group (P < 0.001 and P < 0.05, respectively). The M2 macrophage densities were not associated with patient's survival time. The M1 macrophage densities in the tumor islets, stroma, or islets and stroma

The role of maternal behavior and offspring development in the survival of mountain goat kids.

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Théoret-Gosselin, Rachel; Hamel, Sandra; Côté, Steeve D

2015-05-01

Studies on juvenile survival have mainly focused on the effects of environmental conditions and maternal traits. However, growing evidence indicates that the ability of parents to care for their young and the offspring developmental behaviors could be key determinants of their survival. We examined the relative influence of (1) environmental conditions, (2) offspring traits, (3) maternal traits, (4) maternal care behaviors, and (5) offspring developmental behaviors on kid survival to weaning and to 1 year old in mountain goats (Oreamnos americanus). Offspring development and maternal care directly affected offspring survival, and this more importantly than did environmental conditions and maternal traits. Frequency of play strongly increased survival before weaning. Greater maternal care increased offspring survival during winter, directly and indirectly through kid mass. Kid mass was also a major determinant of both summer and winter survival. Environmental conditions mainly influenced summer survival while maternal characteristics indirectly affected winter survival through an effect on kid mass. Behavioral adaptations of maternal care and offspring development to local selective pressures can lead to local adaptations and have greater implications in population dynamic studies than previously believed.

Enhancing the child survival agenda to promote, protect, and support early child development.

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Jensen, Sarah K G; Bouhouch, Raschida R; Walson, Judd L; Daelmans, Bernadette; Bahl, Rajiv; Darmstadt, Gary L; Dua, Tarun

2015-08-01

High rates of child mortality and lost developmental potential in children under 5 years of age remain important challenges and drivers of inequity in the developing world. Substantive progress has been made toward Millennium Development Goal (MDG) 4 to improve child survival, but as we move into the post-2015 sustainable development agenda, much more work is needed to ensure that all children can realize their full and holistic physical, cognitive, psychological, and socio-emotional development potential. This article presents child survival and development as a continuous and multifaceted process and suggests that a life-course perspective of child development should be at the core of future policy making, programming, and research. We suggest that increased attention to child development, beyond child survival, is key to operationalize the sustainable development goals (SDGs), address inequities, build on the demographic dividend, and maximize gains in human potential. An important step toward implementation will be to increase integration of existing interventions for child survival and child development. Integrated interventions have numerous potential benefits, including optimization of resource use, potential additive impacts across multiple domains of health and development, and opportunity to realize a more holistic approach to client-centered care. However, a notable challenge to integration is the continued division between the health sector and other sectors that support child development. Despite these barriers, empirical evidence is available to suggest that successful multisectoral coordination is feasible and leads to improved short- and long-term outcomes in human, social, and economic development. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of different diets and rearing tanks on the development and larval survival of Lysmata amboinensis (De Mann, 1888

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Daniel Marques

2014-06-01

Full Text Available The optimization of rearing tanks and identification of rich nutritional diets for the larval development of ornamental decapods are two key factors in defining suitable protocols for larval rearing. The main objective of this study was to evaluate the effect of two rearing tanks (spheroconical and planktonkreisel and three different diets (diet 1: newly hatched Artemia nauplii on a density of 5 nauplii/ml, diet 2: newly hatched Artemia nauplii and harpacticoid copepods on a proportion of 3 artemia nauplii and 2 copepods/ml, Diet 3: Tetraselmis chuii for the first 24h, followed by Artemia nauplii at a density of 5 nauplii/ml on the survival rate and larval development time of Lysmata amboinensis. The results here obtained indicated that the survival rate at 10 days after hatching on kreisel tanks (48.9 ± 3.60% was significantly higher than spheroconical tanks (16.2 ± 2.80% (PTetraselmis chuii was used as a first food (76.7 ± 6.67%. The development time from Zoea I to Zoea IV of L. amboinensis was faster when subject to diet 1 (7.5 ± 0.01 days. In contrast, diet 3 was revealed a longer development period (8.2 ± 0.01 days. The use of copepods diet on the larval rearing of L. amboinensis larvae although not displaying the highest survival, revealed to be extremely promising, needing to adjust the size of the prey throughout the larval development of L. amboinensis.

Mean exit time and survival probability within the CTRW formalism

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Montero, M.; Masoliver, J.

2007-05-01

An intense research on financial market microstructure is presently in progress. Continuous time random walks (CTRWs) are general models capable to capture the small-scale properties that high frequency data series show. The use of CTRW models in the analysis of financial problems is quite recent and their potentials have not been fully developed. Here we present two (closely related) applications of great interest in risk control. In the first place, we will review the problem of modelling the behaviour of the mean exit time (MET) of a process out of a given region of fixed size. The surveyed stochastic processes are the cumulative returns of asset prices. The link between the value of the MET and the timescale of the market fluctuations of a certain degree is crystal clear. In this sense, MET value may help, for instance, in deciding the optimal time horizon for the investment. The MET is, however, one among the statistics of a distribution of bigger interest: the survival probability (SP), the likelihood that after some lapse of time a process remains inside the given region without having crossed its boundaries. The final part of the manuscript is devoted to the study of this quantity. Note that the use of SPs may outperform the standard “Value at Risk" (VaR) method for two reasons: we can consider other market dynamics than the limited Wiener process and, even in this case, a risk level derived from the SP will ensure (within the desired quintile) that the quoted value of the portfolio will not leave the safety zone. We present some preliminary theoretical and applied results concerning this topic.

Effect of 153Sm-EDTMP on survival time in patients with nasopharyngeal carcinoma and multiple bone metastases

International Nuclear Information System (INIS)

Fan Wei; Zheng Zongyuan; Xu Guangpu

2004-01-01

Objective: To evaluate the effect on survival of Samarium-153-ethylene diamine tetramethylene phosphonate (153Sm-EDTMP) in patients with nasopharyngeal carcinoma (NPC) and multiple bone metastases. Methods: From 1993 to 1999, 160 patients (127 men, 33 women; median age 35 years) presented with NPC and multiple bone metastases. Of these, 40 patients had undergone chemotherapy, and 72 palliative radiotherapy. Patients were randomly divided into four groups: Group 1 (N = 20) received analgesics (control); Groups 2, 3 and 4 (N = 80, 40, and 20, respectively) received one, two or three courses, respectively, of 153Sm-EDTMP (77.7 MBq/kg/course; course interval, 4 wk). Results: Eight patients died of non-cancer-related causes, and 24 were lost to follow-up. The median survival time for Group 1 (7.8 months) was significantly less (p < 0.05) than that of Groups 2, 3 and 4 (11.6, 13.4 and 12.8 months, respectively). Patients given 153Sm-EDTMP who had had revious external radiation survived longer (p < 0.05) than those in the other treatment groups. Conclusions: Internal radiotherapy with 153Sm-EDTMP can extend survival time in patients with nasopharyngeal carcinoma and multiple bone metastases; when combined with external radiotherapy in appropriate patients, its effect on survival time is enhanced.. (authors)

Effect of a long-term high-protein diet on survival, obesity development, and gut microbiota in mice.

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Kiilerich, Pia; Myrmel, Lene Secher; Fjære, Even; Hao, Qin; Hugenholtz, Floor; Sonne, Si Brask; Derrien, Muriel; Pedersen, Lone Møller; Petersen, Rasmus Koefoed; Mortensen, Alicja; Licht, Tine Rask; Rømer, Maria Unni; Vogel, Ulla Birgitte; Waagbø, Linn Jeanette; Giallourou, Natasa; Feng, Qiang; Xiao, Liang; Liu, Chuan; Liaset, Bjørn; Kleerebezem, Michiel; Wang, Jun; Madsen, Lise; Kristiansen, Karsten

2016-06-01

Female C57BL/6J mice were fed a regular low-fat diet or high-fat diets combined with either high or low protein-to-sucrose ratios during their entire lifespan to examine the long-term effects on obesity development, gut microbiota, and survival. Intake of a high-fat diet with a low protein/sucrose ratio precipitated obesity and reduced survival relative to mice fed a low-fat diet. By contrast, intake of a high-fat diet with a high protein/sucrose ratio attenuated lifelong weight gain and adipose tissue expansion, and survival was not significantly altered relative to low-fat-fed mice. Our findings support the notion that reduced survival in response to high-fat/high-sucrose feeding is linked to obesity development. Digital gene expression analyses, further validated by qPCR, demonstrated that the protein/sucrose ratio modulated global gene expression over time in liver and adipose tissue, affecting pathways related to metabolism and inflammation. Analysis of fecal bacterial DNA using the Mouse Intestinal Tract Chip revealed significant changes in the composition of the gut microbiota in relation to host age and dietary fat content, but not the protein/sucrose ratio. Accordingly, dietary fat rather than the protein/sucrose ratio or adiposity is a major driver shaping the gut microbiota, whereas the effect of a high-fat diet on survival is dependent on the protein/sucrose ratio. Copyright © 2016 the American Physiological Society.

Development and survival of Aulacorthum solani, Macrosiphum euphorbiae and Uroleucon ambrosiae at six temperatures

NARCIS (Netherlands)

Conti, de B.F.; Bueno, V.H.P.; Sampaio, M.V.; Lenteren, van J.C.

2011-01-01

Temperature is one of the most important factors in determining the survival and developmental rate of aphids. The aim of this study was to evaluate the developmental time and survival of the aphid species Aulacorthum solani (Kaltenbach), Macrosiphum euphorbiae (Thomas) and Uroleucon ambrosiae

Significance and survival of Enterococci during the house fly development.

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Ghosh, Anuradha; Akhtar, Mastura; Holderman, Chris; Zurek, Ludek

2014-01-01

House flies are among the most important nonbiting insect pests of medical and veterinary importance. Larvae develop in decaying organic substrates and their survival strictly depends on an active microbial community. House flies have been implicated in the ecology and transmission of enterococci, including multi-antibiotic-resistant and virulent strains of Enterococcus faecalis. In this study, eight American Type Culture Collection type strains of enterococci including Enterococcus avium, Enterococcus casseliflavus, Enterococcus durans, Enterococcus hirae, Enterococcus mundtii, Enterococcus gallinarum, Enterococcusfaecalis, and Enterococcusfaecium were evaluated for their significance in the development of house flies from eggs to adults in bacterial feeding assays. Furthermore, the bacterial colonization of the gut of teneral flies as well as the importance of several virulence traits of E. faecalis in larval mortality was assessed. Overall survival of house flies (egg to adult) was significantly higher when grown with typically nonpathogenic enterococcal species such as E. hirae (76.0% survival), E. durans (64.0%), and E. avium (64.0%) compared with that with clinically important species E. faecalis (24.0%) and E. faecium (36.0%). However, no significant differences in survival of house fly larvae were detected when grown with E. faecalis strains carrying various virulence traits, including isogenic mutants of the human clinical isolate E. faecalis V583 with in-frame deletions of gelatinase, serine protease, and capsular polysaccharide serotype C. Enterococci were commonly detected in fly puparia (range: 75-100%; concentration: 103-105 CFU/puparium);however, the prevalence of enterococci in teneral flies varied greatly: from 25.0 (E. casseliflavus) to 89.5% (E. hirae). In conclusion, depending on the species, enterococci variably support house fly larval development and colonize the gut of teneral adults. The human pathogenic species, E. faecalis and E. faecium

Survival times of patients with a first hip fracture with and without subsequent major long-bone fractures.

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Angthong, Chayanin; Angthong, Wirana; Harnroongroj, Thos; Naito, Masatoshi; Harnroongroj, Thossart

2013-01-01

Survival rates are poorer after a second hip fracture than after a first hip fracture. Previous survival studies have included in-hospital mortality. Excluding in-hospital deaths from the analysis allows survival times to be evaluated in community-based patients. There is still a lack of data regarding the effects of subsequent fractures on survival times after hospital discharge following an initial hip fracture. This study compared the survival times of community-dwelling patients with hip fracture who had or did not have a subsequent major long-bone fracture. Hazard ratios and risk factors for subsequent fractures and mortality rates with and without subsequent fractures were calculated. Of 844 patients with hip fracture from 2000 through 2008, 71 had a subsequent major long-bone fracture and 773 did not. Patients who died of other causes, such as perioperative complications, during hospitalization were excluded. Such exclusion allowed us to determine the effect of subsequent fracture on the survival of community-dwelling individuals after hospital discharge or after the time of the fracture if they did not need hospitalization. Demographic data, causes of death, and mortality rates were recorded. Differences in mortality rates between the patient groups and hazard ratios were calculated. Mortality rates during the first year and from 1 to 5 years after the most recent fracture were 5.6% and 1.4%, respectively, in patients with subsequent fractures, and 4.7% and 1.4%, respectively, in patients without subsequent fractures. These rates did not differ significantly between the groups. Cox regression analysis and calculation of hazard ratios did not show significant differences between patients with subsequent fractures and those without. On univariate and multivariate analyses, age fracture. This study found that survival times did not differ significantly between patients with and without subsequent major long-bone fractures after hip fracture. Therefore, all

Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves.

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Guyot, Patricia; Ades, A E; Ouwens, Mario J N M; Welton, Nicky J

2012-02-01

The results of Randomized Controlled Trials (RCTs) on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio. These do not constitute the sufficient statistics required for meta-analysis or cost-effectiveness analysis, and their use in secondary analyses requires strong assumptions that may not have been adequately tested. In order to enhance the quality of secondary data analyses, we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated. We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations, using where available information on number of events and numbers at risk. The reproducibility and accuracy of survival probabilities, median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics (survival probabilities, medians and hazard ratios) with statistics based on repeated reconstructions by multiple observers. The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics. Accuracy was excellent for survival probabilities and medians, for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported. The algorithm is a reliable tool for meta-analysis and cost-effectiveness analyses of RCTs reporting time-to-event data. It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves.

Intact fetal ovarian cord formation promotes mouse oocyte survival and development

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Pera Renee

2010-01-01

Full Text Available Abstract Background Female reproductive potential, or the ability to propagate life, is limited in mammals with the majority of oocytes lost before birth. In mice, surviving perinatal oocytes are enclosed in ovarian follicles for subsequent oocyte development and function in the adult. Before birth, fetal germ cells of both sexes develop in clusters, or germline cysts, in the undifferentiated gonad. Upon sex determination of the fetal gonad, germ cell cysts become organized into testicular or ovarian cord-like structures and begin to interact with gonadal somatic cells. Although germline cysts and testicular cords are required for spermatogenesis, the role of cyst and ovarian cord formation in mammalian oocyte development and female fertility has not been determined. Results Here, we examine whether intact fetal ovarian germ and somatic cell cord structures are required for oocyte development using mouse gonad re-aggregation and transplantation to disrupt gonadal organization. We observed that germ cells from disrupted female gonad prior to embryonic day e13.5 completed prophase I of meiosis but did not survive following transplantation. Furthermore, re-aggregated ovaries from e13.5 to e15.5 developed with a reduced number of oocytes. Oocyte loss occurred before follicle formation and was associated with an absence of ovarian cord structure and ovary disorganization. However, disrupted ovaries from e16.5 or later were resistant to the re-aggregation impairment and supported robust oocyte survival and development in follicles. Conclusions Thus, we demonstrate a critical window of oocyte development from e13.5 to e16.5 in the intact fetal mouse ovary, corresponding to the establishment of ovarian cord structure, which promotes oocyte interaction with neighboring ovarian somatic granulosa cells before birth and imparts oocytes with competence to survive and develop in follicles. Because germline cyst and ovarian cord structures are conserved in the

A comparative study of machine learning methods for time-to-event survival data for radiomics risk modelling.

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Leger, Stefan; Zwanenburg, Alex; Pilz, Karoline; Lohaus, Fabian; Linge, Annett; Zöphel, Klaus; Kotzerke, Jörg; Schreiber, Andreas; Tinhofer, Inge; Budach, Volker; Sak, Ali; Stuschke, Martin; Balermpas, Panagiotis; Rödel, Claus; Ganswindt, Ute; Belka, Claus; Pigorsch, Steffi; Combs, Stephanie E; Mönnich, David; Zips, Daniel; Krause, Mechthild; Baumann, Michael; Troost, Esther G C; Löck, Steffen; Richter, Christian

2017-10-16

Radiomics applies machine learning algorithms to quantitative imaging data to characterise the tumour phenotype and predict clinical outcome. For the development of radiomics risk models, a variety of different algorithms is available and it is not clear which one gives optimal results. Therefore, we assessed the performance of 11 machine learning algorithms combined with 12 feature selection methods by the concordance index (C-Index), to predict loco-regional tumour control (LRC) and overall survival for patients with head and neck squamous cell carcinoma. The considered algorithms are able to deal with continuous time-to-event survival data. Feature selection and model building were performed on a multicentre cohort (213 patients) and validated using an independent cohort (80 patients). We found several combinations of machine learning algorithms and feature selection methods which achieve similar results, e.g. C-Index = 0.71 and BT-COX: C-Index = 0.70 in combination with Spearman feature selection. Using the best performing models, patients were stratified into groups of low and high risk of recurrence. Significant differences in LRC were obtained between both groups on the validation cohort. Based on the presented analysis, we identified a subset of algorithms which should be considered in future radiomics studies to develop stable and clinically relevant predictive models for time-to-event endpoints.

Testing the effect of dietary carotenoids on larval survival, growth and development in the critically endangered southern corroboree frog.

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Byrne, Phillip G; Silla, Aimee J

2017-03-01

The success of captive breeding programs (CBPs) for threatened species is often limited due to a lack of knowledge of the nutritional conditions required for optimal growth and survival. Carotenoids are powerful antioxidants known to accelerate vertebrate growth and reduce mortality. However, the effect of carotenoids on amphibian life-history traits remains poorly understood. The aim of our study was to use a manipulative laboratory experiment to test the effect of dietary-carotenoid supplementation during the larval life stage on the survival, growth and development of the critically endangered southern corroboree frog (Pseudophryne corroboree). Larvae were fed either a carotenoid supplemented diet or an unsupplemented diet and the survival, growth and development of individuals was monitored and compared. There was no significant effect of dietary treatment on larval survival, growth rate, time taken to reach metamorphosis, or body size at metamorphosis. Our findings provide no evidence that carotenoid supplementation during the larval life stage improves the growth and development of southern corroboree frogs. However, because the carotenoid dose used in our study did not have any detrimental effects on P. corroboree larvae, but has previously been shown to improve adult coloration, immunity, and exercise performance, carotenoid supplementation should be considered when evaluating the nutritional requirements of P. corroboree in captivity. Carotenoid supplementation studies are now required for a diversity of anuran species to determine the effects of carotenoids on amphibian survival, growth and development. Understanding the effects of dietary carotenoids on different life-history traits may assist with amphibian captive breeding and conservation. © 2017 Wiley Periodicals, Inc.

The accuracy of survival time prediction for patients with glioma is improved by measuring mitotic spindle checkpoint gene expression.

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Li Bie

Full Text Available Identification of gene expression changes that improve prediction of survival time across all glioma grades would be clinically useful. Four Affymetrix GeneChip datasets from the literature, containing data from 771 glioma samples representing all WHO grades and eight normal brain samples, were used in an ANOVA model to screen for transcript changes that correlated with grade. Observations were confirmed and extended using qPCR assays on RNA derived from 38 additional glioma samples and eight normal samples for which survival data were available. RNA levels of eight major mitotic spindle assembly checkpoint (SAC genes (BUB1, BUB1B, BUB3, CENPE, MAD1L1, MAD2L1, CDC20, TTK significantly correlated with glioma grade and six also significantly correlated with survival time. In particular, the level of BUB1B expression was highly correlated with survival time (p<0.0001, and significantly outperformed all other measured parameters, including two standards; WHO grade and MIB-1 (Ki-67 labeling index. Measurement of the expression levels of a small set of SAC genes may complement histological grade and other clinical parameters for predicting survival time.

It's Deja Vu All over Again: Using Multiple-Spell Discrete-Time Survival Analysis.

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Willett, John B.; Singer, Judith D.

1995-01-01

The multiple-spell discrete-time survival analysis method is introduced and illustrated using longitudinal data on exit from and reentry into the teaching profession. The method is applicable to many educational problems involving the sequential occurrence of disparate events or episodes. (SLD)

Evaluation of Survival Time of Tooth Color Dental Materials in Primary Anterior Teeth

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Behjat-Al-Molook Ajami

2013-01-01

Full Text Available Introduction: In restorative dentistry, selecting the proper material is an important factor for clinical success. The objective of this study was clinical evaluation of survival time of three tooth color materials in primary anterior teeth. Methods: In this interventional clinical trial study, 94 deciduous anterior teeth (36 teeth in boys, 58 teeth in girls belonging to 3-5 year old children in Pediatric Department of Mashhad Faculty of Dentistry, Iran were selected. Selective dental materials included compoglass, glass-ionomer Fuji II LC, and composite resin. The data were analyzed with Kaplan–Meyer and Log rank test. Results: compoglass had the highest survival time in comparison with composite and glass-ionomer. Nine months retention rate for teeth restored with compoglass, composite resin and glass-ionomer were estimated: 95%, 21%, and 12.5%, respectively. Conclusion: Compoglass can be a suitable material for anterior primary teeth restoration

Evaluation of Survival Time of Tooth Color Dental Materials in Primary Anterior Teeth

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Taraneh Movahhed

2012-09-01

Full Text Available Introduction: In restorative dentistry, selecting the proper material is an important factor for clinical success. The objective of this study was clinical evaluation of survival time of three tooth color materials in primary anterior teeth. Methods: In this interventional clinical trial study, 94 deciduous anterior teeth (36 teeth in boys, 58 teeth in girls belonging to 3-5 year old children in Pediatric Department of Mashhad Faculty of Dentistry, Iran were selected. Selective dental materials included compoglass, glass-ionomer Fuji II LC, and composite resin. The data were analyzed with Kaplan–Meyer and Log rank test. Results: compoglass had the highest survival time in comparison with composite and glass-ionomer. Nine months retention rate for teeth restored with compoglass, composite resin and glass-ionomer were estimated: 95%, 21%, and 12.5%, respectively. Conclusion: Compoglass can be a suitable material for anterior primary teeth restoration.

Effects of the chitin synthesis inhibitor buprofezin on survival and development of immatures of Chrysoperla rufilabris (Neuroptera: Chrysopidae).

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Liu, T X; Chen, T Y

2000-04-01

Effects of buprofezin (Applaud), a chitin synthesis inhibitor, on survival and development of eggs, three instars, and pupae of Chrysoperla rufilabris (Burmeister) were determined in the laboratory. Buprofezin at three tested concentrations (100, 500, and 1,000 mg [AI]/liter) did not affect the viability and development of eggs when the eggs were treated, or third instars and pupae when those stages were treated. Although the degree of effects by buprofezin on larvae varied with instar, buprofezin at the higher concentrations (500 and 1,000 mg [AI]/liter) reduced survival rates 17-47% and prolonged the overall development from first instars to adult emergence by 2 or 3 d when first instars were treated, indicating that the first instar is the most vulnerable stage. When second instars were treated, the survival of C. rufilabris from second instars to pupae was not significantly affected. However, the developmental time from second instar to adult emergence was longer in the treatments with the highest concentration (1,000 mg [AI]/liter) than that with the lowest concentration (100 mg [AI]/liter). The compatibility of buprofezin with natural enemies in integrated pest management programs is discussed.

Survival with Three-Times Weekly In-Center Nocturnal Versus Conventional Hemodialysis

Science.gov (United States)

Xu, Jianglin; Suri, Rita S.; Nesrallah, Gihad; Lindsay, Robert; Garg, Amit X.; Lester, Keith; Ofsthun, Norma; Lazarus, Michael; Hakim, Raymond M.

2012-01-01

Whether the duration of hemodialysis treatments improves outcomes remains controversial. Here, we evaluated survival and clinical changes associated with converting from conventional hemodialysis (mean=3.75 h/treatment) to in-center nocturnal hemodialysis (mean=7.85 h/treatment). All 959 consecutive patients who initiated nocturnal hemodialysis for the first time in 77 Fresenius Medical Care facilities during 2006 and 2007 were eligible. We used Cox models to compare risk for mortality during 2 years of follow-up in a 1:3 propensity score–matched cohort of 746 nocturnal and 2062 control patients on conventional hemodialysis. Two-year mortality was 19% among nocturnal hemodialysis patients compared with 27% among conventional patients. Nocturnal hemodialysis associated with a 25% reduction in the risk for death after adjustment for age, body mass index, and dialysis vintage (hazard ratio=0.75, 95% confidence interval=0.61–0.91, P=0.004). With respect to clinical features, interdialytic weight gain, albumin, hemoglobin, dialysis dose, and calcium increased on nocturnal therapy, whereas postdialysis weight, predialysis systolic blood pressure, ultrafiltration rate, phosphorus, and white blood cell count declined (all P<0.001). In summary, notwithstanding the possibility of residual selection bias, conversion to treatment with nocturnal hemodialysis associates with favorable clinical features, laboratory biomarkers, and improved survival compared with propensity score–matched controls. The potential impact of extended treatment time on clinical outcomes while maintaining a three times per week hemodialysis schedule requires evaluation in future clinical trials. PMID:22362905

Biologically-equivalent dose and long-term survival time in radiation treatments

International Nuclear Information System (INIS)

Zaider, Marco; Hanin, Leonid

2007-01-01

Within the linear-quadratic model the biologically-effective dose (BED)-taken to represent treatments with an equal tumor control probability (TCP)-is commonly (and plausibly) calculated according to BED(D) = -log[S(D)]/α. We ask whether in the presence of cellular proliferation this claim is justified and examine, as a related question, the extent to which BED approximates an isoeffective dose (IED) defined, more sensibly, in terms of an equal long-term survival probability, rather than TCP. We derive, under the assumption that cellular birth and death rates are time homogeneous, exact equations for the isoeffective dose, IED. As well, we give a rigorous definition of effective long-term survival time, T eff . By using several sets of radiobiological parameters, we illustrate potential differences between BED and IED on the one hand and, on the other, between T eff calculated as suggested here or by an earlier recipe. In summary: (a) the equations currently in use for calculating the effective treatment time may underestimate the isoeffective dose and should be avoided. The same is the case for the tumor control probability (TCP), only more so; (b) for permanent implants BED may be a poor substitute for IED; (c) for a fractionated treatment schedule, interpreting the observed probability of cure in terms of a TCP formalism that refers to the end of the treatment (rather than T eff ) may result in a miscalculation (underestimation) of the initial number of clonogens

Survival analysis

International Nuclear Information System (INIS)

Badwe, R.A.

1999-01-01

The primary endpoint in the majority of the studies has been either disease recurrence or death. This kind of analysis requires a special method since all patients in the study experience the endpoint. The standard method for estimating such survival distribution is Kaplan Meier method. The survival function is defined as the proportion of individuals who survive beyond certain time. Multi-variate comparison for survival has been carried out with Cox's proportional hazard model

Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves

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Guyot Patricia

2012-02-01

Full Text Available Abstract Background The results of Randomized Controlled Trials (RCTs on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio. These do not constitute the sufficient statistics required for meta-analysis or cost-effectiveness analysis, and their use in secondary analyses requires strong assumptions that may not have been adequately tested. In order to enhance the quality of secondary data analyses, we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated. Methods We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations, using where available information on number of events and numbers at risk. The reproducibility and accuracy of survival probabilities, median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics (survival probabilities, medians and hazard ratios with statistics based on repeated reconstructions by multiple observers. Results The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics. Accuracy was excellent for survival probabilities and medians, for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported. Conclusion The algorithm is a reliable tool for meta-analysis and cost-effectiveness analyses of RCTs reporting time-to-event data. It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves.

Pre-hospital transport times and survival for Hypotensive patients with penetrating thoracic trauma

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Mamta Swaroop

2013-01-01

Full Text Available Background: Achieving definitive care within the "Golden Hour" by minimizing response times is a consistent goal of regional trauma systems . This study hypothesizes that in urban Level I Trauma Centers, shorter pre-hospital times would predict outcomes in penetrating thoracic injuries. Materials and Methods: A retrospective cohort study was performed using a statewide trauma registry for the years 1999-2003 . Total pre-hospital times were measured for urban victims of penetrating thoracic trauma. Crude and adjusted mortality rates were compared by pre-hospital time using STATA statistical software. Results: During the study period, 908 patients presented to the hospital after penetrating thoracic trauma, with 79% surviving . Patients with higher injury severity scores (ISS were transported more quickly. Injury severity scores (ISS ≥16 and emergency department (ED hypotension (systolic blood pressure, SBP <90 strongly predicted mortality (P < 0.05 for each . In a logistic regression model including age, race, and ISS, longer transport times for hypotensive patients were associated with higher mortality rates (all P values <0.05. This was seen most significantly when comparing patient transport times 0-15 min and 46-60 min (P < 0.001. Conclusion: In victims of penetrating thoracic trauma, more severely injured patients arrive at urban trauma centers sooner . Mortality is strongly predicted by injury severity, although shorter pre-hospital times are associated with improved survival . These results suggest that careful planning to optimize transport time-encompassing hospital capacity and existing resources, traffic patterns, and trauma incident densities may be beneficial in areas with a high burden of penetrating trauma.

The effect of unilateral ovariectomy on early embryonic survival and embryo development in rabbits

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R. Peiró

2014-06-01

Full Text Available Unilateral ovariectomy can be used to study uterine capacity in rabbits because an overcrowding of the functional uterine horn is produced. Due to the uterus duplex, the rabbit is the ideal model for such studies. However, this technique may affect embryo survival. The aim of this work is to study the effect of unilateral ovariectomy on early embryo survival and development in rabbit. A total of 101 unilateral ovariectomised females and 52 intact females were compared after slaughter at 30 h post-mating. Early embryo survival was estimated as the ratio between number of embryo recovered and ovulation rate. No differences were found between intact and unilaterally ovariectomised females in this trait. Unilateral ovariectomy did not change embryo development, measured as the number of embryo cells. Variability of embryo development was not affected either. At 30 h post-mating, the majority of embryos (86.2% were 4-cell stage. Embryo quality was evaluated according to morphological criteria. No difference in embryo quality between intact and unilaterally ovariectomised females was found. Therefore, unilateral ovariectomy performed before puberty in rabbit does not modify early embryo survival and development.

Effect of bifidobacteria implantation on the survival time of whole-body irradiated mice

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Yokokura, Teruo; Onoue, Masaharu; Mutai, Masahiko

1980-01-01

Letahl dose (2 KR) of gamma-ray was irradiated on the whole bodies of mice. Survival time after irradiation was significantly longer in mice with administration of both Bifidobacterium breve YIT 4008 and transgalactosyl oligosaccharide than in mice with administration of either of the two or nothing. (Tsunoda, M.)

Adjuvant Radiation Therapy Treatment Time Impacts Overall Survival in Gastric Cancer

International Nuclear Information System (INIS)

McMillan, Matthew T.; Ojerholm, Eric; Roses, Robert E.; Plastaras, John P.; Metz, James M.; Mamtani, Ronac; Karakousis, Giorgos C.; Fraker, Douglas L.; Drebin, Jeffrey A.; Stripp, Diana; Ben-Josef, Edgar; Datta, Jashodeep

2015-01-01

Purpose: Prolonged radiation therapy treatment time (RTT) is associated with worse survival in several tumor types. This study investigated whether delays during adjuvant radiation therapy impact overall survival (OS) in gastric cancer. Methods and Materials: The National Cancer Data Base was queried for patients with resected gastric cancer who received adjuvant radiation therapy with National Comprehensive Cancer Network–recommended doses (45 or 50.4 Gy) between 1998 and 2006. RTT was classified as standard (45 Gy: 33-36 days, 50.4 Gy: 38-41 days) or prolonged (45 Gy: >36 days, 50.4 Gy: >41 days). Cox proportional hazards models evaluated the association between the following factors and OS: RTT, interval from surgery to radiation therapy initiation, interval from surgery to radiation therapy completion, radiation therapy dose, demographic/pathologic and operative factors, and other elements of adjuvant multimodality therapy. Results: Of 1591 patients, RTT was delayed in 732 (46%). Factors associated with prolonged RTT were non-private health insurance (OR 1.3, P=.005) and treatment at non-academic facilities (OR 1.2, P=.045). Median OS and 5-year actuarial survival were significantly worse in patients with prolonged RTT compared with standard RTT (36 vs 51 months, P=.001; 39 vs 47%, P=.005); OS worsened with each cumulative week of delay (P<.0004). On multivariable analysis, prolonged RTT was associated with inferior OS (hazard ratio 1.2, P=.002); the intervals from surgery to radiation therapy initiation or completion were not. Prolonged RTT was particularly detrimental in patients with node positivity, inadequate nodal staging (<15 nodes examined), and those undergoing a cycle of chemotherapy before chemoradiation therapy. Conclusions: Delays during adjuvant radiation therapy appear to negatively impact survival in gastric cancer. Efforts to minimize cumulative interruptions to <7 days should be considered

Adjuvant Radiation Therapy Treatment Time Impacts Overall Survival in Gastric Cancer

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McMillan, Matthew T. [Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Ojerholm, Eric [Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Roses, Robert E., E-mail: Robert.Roses@uphs.upenn.edu [Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Plastaras, John P.; Metz, James M. [Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Mamtani, Ronac [Department of Hematology/Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Karakousis, Giorgos C.; Fraker, Douglas L.; Drebin, Jeffrey A. [Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Stripp, Diana; Ben-Josef, Edgar [Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Datta, Jashodeep [Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States)

2015-10-01

Purpose: Prolonged radiation therapy treatment time (RTT) is associated with worse survival in several tumor types. This study investigated whether delays during adjuvant radiation therapy impact overall survival (OS) in gastric cancer. Methods and Materials: The National Cancer Data Base was queried for patients with resected gastric cancer who received adjuvant radiation therapy with National Comprehensive Cancer Network–recommended doses (45 or 50.4 Gy) between 1998 and 2006. RTT was classified as standard (45 Gy: 33-36 days, 50.4 Gy: 38-41 days) or prolonged (45 Gy: >36 days, 50.4 Gy: >41 days). Cox proportional hazards models evaluated the association between the following factors and OS: RTT, interval from surgery to radiation therapy initiation, interval from surgery to radiation therapy completion, radiation therapy dose, demographic/pathologic and operative factors, and other elements of adjuvant multimodality therapy. Results: Of 1591 patients, RTT was delayed in 732 (46%). Factors associated with prolonged RTT were non-private health insurance (OR 1.3, P=.005) and treatment at non-academic facilities (OR 1.2, P=.045). Median OS and 5-year actuarial survival were significantly worse in patients with prolonged RTT compared with standard RTT (36 vs 51 months, P=.001; 39 vs 47%, P=.005); OS worsened with each cumulative week of delay (P<.0004). On multivariable analysis, prolonged RTT was associated with inferior OS (hazard ratio 1.2, P=.002); the intervals from surgery to radiation therapy initiation or completion were not. Prolonged RTT was particularly detrimental in patients with node positivity, inadequate nodal staging (<15 nodes examined), and those undergoing a cycle of chemotherapy before chemoradiation therapy. Conclusions: Delays during adjuvant radiation therapy appear to negatively impact survival in gastric cancer. Efforts to minimize cumulative interruptions to <7 days should be considered.

Bronchiolitis obliterans syndrome after single-lung transplantation: impact of time to onset on functional pattern and survival.

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Brugière, Olivier; Pessione, Fabienne; Thabut, Gabriel; Mal, Hervé; Jebrak, Gilles; Lesèche, Guy; Fournier, Michel

2002-06-01

Among risk factors for the progression of bronchiolitis obliterans syndrome (BOS) after lung transplantation (LT), the influence of time to BOS onset is not known. The aim of the study was to assess if BOS occurring earlier after LT is associated with worse functional prognosis and worse graft survival. We retrospectively compared functional outcome and survival of all single-LT (SLT) recipients who had BOS develop during follow-up in our center according to time to onset of BOS ( or = 3 years after transplantation). Among the 29 SLT recipients with BOS identified during the study period, 20 patients had early-onset BOS and 9 patients had late-onset BOS. The mean decline of FEV(1) over time during the first 9 months in patients with early-onset BOS was significantly greater than in patients with of late-onset BOS (p = 0.04). At last follow-up, patients with early-onset BOS had a lower mean FEV(1) value (25% vs 39% of predicted, p = 0.004), a lower mean PaO(2) value (54 mm Hg vs 73 mm Hg, p = 0.0005), a lower 6-min walk test distance (241 m vs 414 m, p = 0.001), a higher Medical Research Council index value (3.6 vs 1.6, p = 0.0001), and a higher percentage of oxygen dependency (90% vs 11%, p = 0.001) compared with patients with late-onset BOS. In addition, graft survival of patients with early-onset BOS was significantly lower than that of patients with late-onset BOS (log-rank test, p = 0.04). There were 18 of 20 graft failures (90%) in the early-onset BOS group, directly attributable to BOS in all cases (deaths [n = 10] or retransplantation [n = 8]). In the late-onset BOS group, graft failure occurred in four of nine patients due to death from extrapulmonary causes in three of four cases. The median duration of follow-up after occurrence of BOS was not statistically different between patients with early-onset BOS and patients with late-onset BOS (31 +/- 28 months and 37 +/- 26 months, respectively; p = not significant). The subgroup of patients who had BOS develop

Modelling survival

DEFF Research Database (Denmark)

Ashauer, Roman; Albert, Carlo; Augustine, Starrlight

2016-01-01

The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test...

Cholesterol Effect on Survival and Development of Larval Mud Crab Scylla serrata

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MUHAMMAD AGUS SUPRAYUDI

2012-03-01

Full Text Available The effect of cholesterol on the survival and development of larval mud crab Scylla serrata were examined by feeding larvae with Artemia enriched with different level of cholesterol. Artemia enriched with four stated levels of cholesterol i.e., 0, 5, 10, and 20 ul/l (Chol 0, 5, 10, and 20. All treatments were mixed with DHA70G at 25 ul/l. All the oil was adjusted to 100 ul/l by adding the oleic acid. Survival rate, intermolt period, and carapace width at the fisrt crab stage of mud crab larvae fed Chol 0, 5, and 10 were higher compared to that of Chol 20 (P < 0.05. We suggest that free sterol contained in Artemia at 1.37% was harmful to the growth performance of mud crab larvae. This study suggests that mud crab larvae required at least 0.61% cholesterol for maintaining good survival and development and therefore no need to enrich Artemia by cholesterol for the practical purpose.

Survival and development of chicken ascarid eggs in temperate pastures

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Thapa, Sundar; Thamsborg, Stig Milan; Meyling, Nicolai Vitt

2017-01-01

Eggs of chicken ascarids (Ascaridia galli and Heterakis spp.) are believed to be hardy and survive for long periods. However, this has not been evaluated quantitatively and our study therefore aimed to determine development and recovery of chicken ascarid eggs after burying in pasture soil...

Effects of photoperiod on boll weevil (Coleoptera: Curculionidae) development, survival, and reproduction.

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Greenberg, S M; Sappington, T W; Adamczyk, J J; Liu, T-X; Setamou, M

2008-12-01

Effects of photoperiod on development, survival, feeding, and oviposition of boll weevils, Anthonomus grandis grandis Boheman, were assessed under five different photophases (24, 14, 12, 10, and 0 h) at a constant 27 degrees C temperature and 65% RH in the laboratory. Analyses of our results detected positive relationships between photoperiod and puncturing (mean numbers of oviposition and feeding punctures per day), and oviposition (oviposition punctures/oviposition+feeding punctures) activities, and the proportion of squares attacked by boll weevil females. When boll weevil females developed in light:darkness cycles, they produced a significantly higher percentage of eggs developing to adulthood than those developed in 24-h light or dark conditions. In long photoperiod (24:0 and 14:10 h), the number of female progeny was significantly higher and their development time was significantly shorter than those developed in short photoperiod (0:24 and 10:14 h). Lifetime oviposition was significantly highest at 12- and 14-h photophase, lowest at 0- and 10-h photophase, and intermediate at 24 h of light. Life table calculations indicated that boll weevil populations developed in a photoperiod of 14:10 and 12:12 (L:D) h will increase an average of two-fold each generation (Ro) compared with boll weevils developed in 24:0- and 10:14-h photoperiods and 15-fold compared with those at 0:24 h. Knowledge of the photoperiod-dependent population growth potential is critical for understanding population dynamics to better develop sampling protocols and timing insecticide applications.

Political Mechanisms for Long-Range Survival and Development

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Marshall, W.

As the first species aware of extinction and capable of proactively ensuring our long-term survival and development, it is striking that we do not do so with the rigor, formality, and foresight it requires. Only from a reactive posture have we responded to the challenges of global warfare, human rights, environmental concerns, and sustainable development. Despite our awareness of the possibility for extinction and apocalyptic set-backs to our evolution, and despite the existence of long-range studies-which must still be dramatically increased-proactive global policy implementation regarding our long-term survival and development is arguably non-existent. This lack of long-term policy making can be attributed in part to the lack of formal political mechanisms to facilitate longer-range policy making that extends 30 years or more into the future. Political mechanisms for infusing long-range thinking, research, and strategic planning into the policy-making process can help correct this shortcoming and provide the motivation needed to adequately address long-term challenges with the political rigor required to effectively establish and implement long-term policies. There are some efforts that attempt to address longer-range issues, but those efforts often do not connect to the political process, do not extend 30 or more years into the future, are not well-funded, and are not sufficiently systemic. Political mechanisms for long-range survival and prosperity could correct these inadequacies by raising awareness, providing funding, and most importantly, leveraging political rigor to establish and enforce long-range strategic planning and policies. The feasibility of such mechanisms should first be rigorously studied and assessed in a feasibility study, which could then inform implementation. This paper will present the case for such a study and suggest some possible political mechanisms that should be investigated further in the proposed study. This work is being further

Activated ovarian endothelial cells promote early follicular development and survival.

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Kedem, Alon; Aelion-Brauer, Anate; Guo, Peipei; Wen, Duancheng; Ding, Bi-Sen; Lis, Raphael; Cheng, Du; Sandler, Vladislav M; Rafii, Shahin; Rosenwaks, Zev

2017-09-19

New data suggests that endothelial cells (ECs) elaborate essential "angiocrine factors". The aim of this study is to investigate the role of activated ovarian endothelial cells in early in-vitro follicular development. Mouse ovarian ECs were isolated using magnetic cell sorting or by FACS and cultured in serum free media. After a constitutive activation of the Akt pathway was initiated, early follicles (50-150 um) were mechanically isolated from 8-day-old mice and co-cultured with these activated ovarian endothelial cells (AOEC) (n = 32), gel (n = 24) or within matrigel (n = 27) in serum free media for 14 days. Follicular growth, survival and function were assessed. After 6 passages, flow cytometry showed 93% of cells grown in serum-free culture were VE-cadherin positive, CD-31 positive and CD 45 negative, matching the known EC profile. Beginning on day 4 of culture, we observed significantly higher follicular and oocyte growth rates in follicles co-cultured with AOECs compared with follicles on gel or matrigel. After 14 days of culture, 73% of primary follicles and 83% of secondary follicles co-cultured with AOEC survived, whereas the majority of follicles cultured on gel or matrigel underwent atresia. This is the first report of successful isolation and culture of ovarian ECs. We suggest that co-culture with activated ovarian ECs promotes early follicular development and survival. This model is a novel platform for the in vitro maturation of early follicles and for the future exploration of endothelial-follicular communication. In vitro development of early follicles necessitates a complex interplay of growth factors and signals required for development. Endothelial cells (ECs) may elaborate essential "angiocrine factors" involved in organ regeneration. We demonstrate that co-culture with ovarian ECs enables culture of primary and early secondary mouse ovarian follicles.

The Application of Extended Cox Proportional Hazard Method for Estimating Survival Time of Breast Cancer

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Husain, Hartina; Astuti Thamrin, Sri; Tahir, Sulaiha; Mukhlisin, Ahmad; Mirna Apriani, M.

2018-03-01

Breast cancer is one type of cancer that is the leading cause of death worldwide. This study aims to model the factors that affect the survival time and rate of cure of breast cancer patients. The extended cox model, which is a modification of the proportional hazard cox model in which the proportional hazard assumptions are not met, is used in this study. The maximum likelihood estimation approach is used to estimate the parameters of the model. This method is then applied to medical record data of breast cancer patient in 2011-2016, which is taken from Hasanuddin University Education Hospital. The results obtained indicate that the factors that affect the survival time of breast cancer patients are malignancy and leukocyte levels.

Risk-adjusted survival for adults following in-hospital cardiac arrest by day of week and time of day: observational cohort study

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Robinson, Emily J; Power, Geraldine S; Nolan, Jerry; Soar, Jasmeet; Spearpoint, Ken; Gwinnutt, Carl; Rowan, Kathryn M

2016-01-01

Background Internationally, hospital survival is lower for patients admitted at weekends and at night. Data from the UK National Cardiac Arrest Audit (NCAA) indicate that crude hospital survival was worse after in-hospital cardiac arrest (IHCA) at night versus day, and at weekends versus weekdays, despite similar frequency of events. Objective To describe IHCA demographics during three day/time periods—weekday daytime (Monday to Friday, 08:00 to 19:59), weekend daytime (Saturday and Sunday, 08:00 to 19:59) and night-time (Monday to Sunday, 20:00 to 07:59)—and to compare the associated rates of return of spontaneous circulation (ROSC) for >20 min (ROSC>20 min) and survival to hospital discharge, adjusted for risk using previously developed NCAA risk models. To consider whether any observed difference could be attributed to differences in the case mix of patients resident in hospital and/or the administered care. Methods We performed a prospectively defined analysis of NCAA data from 27 700 patients aged ≥16 years receiving chest compressions and/or defibrillation and attended by a hospital-based resuscitation team in response to a resuscitation (2222) call in 146 UK acute hospitals. Results Risk-adjusted outcomes (OR (95% CI)) were worse (p20 min 0.88 (0.81 to 0.95); hospital survival 0.72 (0.64 to 0.80)), and night-time (ROSC>20 min 0.72 (0.68 to 0.76); hospital survival 0.58 (0.54 to 0.63)) compared with weekday daytime. The effects were stronger for non-shockable than shockable rhythms, but there was no significant interaction between day/time of arrest and age, or day/time of arrest and arrest location. While many daytime IHCAs involved procedures, restricting the analyses to IHCAs in medical admissions with an arrest location of ward produced results that are broadly in line with the primary analyses. Conclusions IHCAs attended by the hospital-based resuscitation team during nights and weekends have substantially worse outcomes than during

Unique protein expression signatures of survival time in kidney renal clear cell carcinoma through a pan-cancer screening.

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Han, Guangchun; Zhao, Wei; Song, Xiaofeng; Kwok-Shing Ng, Patrick; Karam, Jose A; Jonasch, Eric; Mills, Gordon B; Zhao, Zhongming; Ding, Zhiyong; Jia, Peilin

2017-10-03

In 2016, it is estimated that there will be 62,700 new cases of kidney cancer in the United States, and 14,240 patients will die from the disease. Because the incidence of kidney renal clear cell carcinoma (KIRC), the most common type of kidney cancer, is expected to continue to increase in the US, there is an urgent need to find effective diagnostic biomarkers for KIRC that could help earlier detection of and customized treatment strategies for the disease. Accordingly, in this study we systematically investigated KIRC's prognostic biomarkers for survival using the reverse phase protein array (RPPA) data and the high throughput sequencing data from The Cancer Genome Atlas (TCGA). With comprehensive data available in TCGA, we systematically screened protein expression based survival biomarkers in 10 major cancer types, among which KIRC presented many protein prognostic biomarkers of survival time. This is in agreement with a previous report that expression level changes (mRNAs, microRNA and protein) may have a better performance for prognosis of KIRC. In this study, we also identified 52 prognostic genes for KIRC, many of which are involved in cell-cycle and cancer signaling, as well as 15 tumor-stage-specific prognostic biomarkers. Notably, we found fewer prognostic biomarkers for early-stage than for late-stage KIRC. Four biomarkers (the RPPA protein IDs: FASN, ACC1, Cyclin_B1 and Rad51) were found to be prognostic for survival based on both protein and mRNA expression data. Through pan-cancer screening, we found that many protein biomarkers were prognostic for patients' survival in KIRC. Stage-specific survival biomarkers in KIRC were also identified. Our study indicated that these protein biomarkers might have potential clinical value in terms of predicting survival in KIRC patients and developing individualized treatment strategies. Importantly, we found many biomarkers in KIRC at both the mRNA expression level and the protein expression level. These

Impact of Sodium Chloride and Heat on Survival Time of Linguatula Serrata Nymphs in vitro: An Experimental Study

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B. Hajimohammadi

2012-07-01

Full Text Available Introduction: Linguatula serrata is a zoonotic parasite, belonging to the class Pentastomida. The major aim of this study was to evaluate the impact of sodium chloride (NaCl and heat on survival time of Linguatula serrata nymphs. Materials & Methods: Thirty nymphs (10 in triplicate were separately transferred to plastic tubes, containing different concentrations of NaCl solution (2%, 5% and 10%. Meanwhile, 30 nymphs in tubes containing Phosphate Buffer Saline (PBS were separately treated by +50°C, +60°C and +72°C. As control group, thirty nymphs were stored in PBS at +4°C. The effects of different conditions on survival time of the nymphs were evaluated by observing their motility in different periods of time. Results: The survival time of the nymphs stored in 10% NaCl solution was too short and all of them were dead after 3 hours. But the other ones maintained in 2% NaCl solution were significantly more resistant (p<0.05 and were survived for 2 days. All the nymphs pertaining to each +60°C and +72°C treatments were found dead after first 5-minute storage interval; the nymphs stored at +50°C died totally after 20 minutes. The nymphs maintained in PBS at +4°C (control group showed the longest survival time (p<0.05; all of them were alive until day 4 and the last ones died on day 34. Conclusion: It is concluded that salting and heating have significant parasiticidal effects on L. serrata nymphs and could be used as disinfecting methods in processing of meat products especially liver. However, refrigeration at +4°C increases the resistance of the nymphs in meat products and therefore might endanger the food safety.

Frozen in Time? Microbial strategies for survival and carbon metabolism over geologic time in a Pleistocene permafrost chronosequence

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Mackelprang, R.; Douglas, T. A.; Waldrop, M. P.

2014-12-01

Permafrost soils have received tremendous interest due to their importance as a global carbon store with the potential to be thawed over the coming centuries. Instead of being 'frozen in time,' permafrost contains active microbes. Most metagenomic studies have focused on Holocene aged permafrost. Here, we target Pleistocene aged ice and carbon rich permafrost (Yedoma), which can differ in carbon content and stage of decay. Our aim was to understand how microbes in the permafrost transform organic matter over geologic time and to identify physiological and biochemical adaptations that enable long-term survival. We used next-generation sequencing to characterize microbial communities along a permafrost age gradient. Samples were collected from the Cold Regions Research and Engineering Laboratory (CRREL) Permafrost Tunnel near Fox, AK, which penetrates a hillside providing access to permafrost ranging in age from 12 to 40 kyr. DNA was extracted directly from unthawed samples. 16S rRNA amplicon (16S) and shotgun metagenome sequencing revealed significant age-driven differences. First, microbial diversity declines with permafrost age, likely due to long-term exposure to environmental stresses and a reduction in metabolic resources. Second, we observed taxonomic differences among ages, with an increasing abundance of Firmicutes (endospore-formers) in older samples, suggesting that dormancy is a common survival strategy in older permafrost. Ordination of 16S and metagenome data revealed age-based clustering. Genes differing significantly between age categories included those involved in lipopolysaccharide assembly, cold-response, and carbon processing. These data point to the physiological adaptations to long-term frozen conditions and to the metabolic processes utilized in ancient permafrost. In fact, a gene common in older samples is involved in cadaverine production, which could potentially explain the putrefied smell of Pleistocene aged permafrost. Coupled with soil

Impacts of maternal dietary protein intake on fetal survival, growth, and development.

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Herring, Cassandra M; Bazer, Fuller W; Johnson, Gregory A; Wu, Guoyao

2018-03-01

Maternal nutrition during gestation, especially dietary protein intake, is a key determinant in embryonic survival, growth, and development. Low maternal dietary protein intake can cause embryonic losses, intra-uterine growth restriction, and reduced postnatal growth due to a deficiency in specific amino acids that are important for cell metabolism and function. Of note, high maternal dietary protein intake can also result in intra-uterine growth restriction and embryonic death, due to amino acid excesses, as well as the toxicity of ammonia, homocysteine, and H 2 S that are generated from amino acid catabolism. Maternal protein nutrition has a pronounced impact on fetal programming and alters the expression of genes in the fetal genome. As a precursor to the synthesis of molecules (e.g. nitric oxide, polyamines, and creatine) with cell signaling and metabolic functions, L-arginine (Arg) is essential during pregnancy for growth and development of the conceptus. With inadequate maternal dietary protein intake, Arg and other important amino acids are deficient in mother and fetus. Dietary supplementation of Arg during gestation has been effective in improving embryonic survival and development of the conceptus in many species, including humans, pigs, sheep, mice, and rats. Both the balance among amino acids and their quantity are critical for healthy pregnancies and offspring. Impact statement This review aims at: highlighting adverse effects of elevated levels of ammonia in mother or fetus on embryonic/fetal survival, growth, and development; helping nutritionists and practitioners to understand the mechanisms whereby elevated levels of ammonia in mother or fetus results in embryonic/fetal death, growth restriction, and developmental abnormalities; and bringing, into the attention of nutritionists and practitioners, the problems of excess or inadequate dietary intake of protein or amino acids on pregnancy outcomes in animals and humans. The article provides new

Development of a likelihood of survival scoring system for hospitalized equine neonates using generalized boosted regression modeling.

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Katarzyna A Dembek

Full Text Available BACKGROUND: Medical management of critically ill equine neonates (foals can be expensive and labor intensive. Predicting the odds of foal survival using clinical information could facilitate the decision-making process for owners and clinicians. Numerous prognostic indicators and mathematical models to predict outcome in foals have been published; however, a validated scoring method to predict survival in sick foals has not been reported. The goal of this study was to develop and validate a scoring system that can be used by clinicians to predict likelihood of survival of equine neonates based on clinical data obtained on admission. METHODS AND RESULTS: Data from 339 hospitalized foals of less than four days of age admitted to three equine hospitals were included to develop the model. Thirty seven variables including historical information, physical examination and laboratory findings were analyzed by generalized boosted regression modeling (GBM to determine which ones would be included in the survival score. Of these, six variables were retained in the final model. The weight for each variable was calculated using a generalized linear model and the probability of survival for each total score was determined. The highest (7 and the lowest (0 scores represented 97% and 3% probability of survival, respectively. Accuracy of this survival score was validated in a prospective study on data from 283 hospitalized foals from the same three hospitals. Sensitivity, specificity, positive and negative predictive values for the survival score in the prospective population were 96%, 71%, 91%, and 85%, respectively. CONCLUSIONS: The survival score developed in our study was validated in a large number of foals with a wide range of diseases and can be easily implemented using data available in most equine hospitals. GBM was a useful tool to develop the survival score. Further evaluations of this scoring system in field conditions are needed.

Survival times with and without tube feeding in patients with dementia or psychiatric diseases in Japan.

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Takayama, Keiko; Hirayama, Keisuke; Hirao, Akihiko; Kondo, Keiko; Hayashi, Hideki; Kadota, Koichi; Asaba, Hiroyuki; Ishizu, Hideki; Nakata, Kenji; Kurisu, Kairi; Oshima, Etsuko; Yokota, Osamu; Yamada, Norihito; Terada, Seishi

2017-11-01

It is widely supposed that there has been no evidence of increased survival in patients with advanced dementia receiving enteral tube feeding. However, more than a few studies have reported no harmful outcome from tube feeding in dementia patients compared to in patients without dementia. This was a retrospective study. Nine psychiatric hospitals in Okayama Prefecture participated in this survey. All inpatients fulfilling the entry criteria were evaluated. All subjects suffered from difficulty with oral intake. Attending physicians thought that the patients could not live without long-term artificial nutrition. The physicians decided whether to make use of long-term artificial nutrition between January 2012 and December 2014. We evaluated 185 patients. Their mean age was 76.6 ± 11.4 years. Of all subjects, patients with probable Alzheimer's disease (n = 78) formed the biggest group, schizophrenia patients (n = 44) the second, and those with vascular dementia (n = 30) the third. The median survival times were 711 days for patients with tube feeding and 61 days for patients without tube feeding. In a comparison different types of tube feeding, median survival times were 611 days for patients with a nasogastric tube and more than 1000 days for those with a percutaneous endoscopic gastrostomy tube. Patients with tube feeding survived longer than those without tube feeding, even among dementia patients. This study suggests that enteral nutrition for patients with dementia prolongs survival. Additionally, percutaneous endoscopic gastrostomy tube feeding may be safer than nasogastric tube feeding among patients in psychiatric hospitals. © 2017 Japanese Psychogeriatric Society.

The impact of chemotherapy and its timing on survival in malignant peritoneal mesothelioma treated with complete debulking.

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Naffouje, Samer A; Tulla, Kiara A; Salti, George I

2018-04-12

The current standard of treatment for malignant peritoneal mesothelioma (MPM) is cytoreductive surgery when the disease distribution is favorable. The role of chemotherapy, as an adjunct to surgery, remains unclear. The national database of mesothelioma was used to identify MPM patients who were treated with curative intent. Patients were divided into treatment groups: (1) chemotherapy only, (2) surgery only, (3) neoadjuvant chemotherapy + surgery, and (4) surgery + adjuvant chemotherapy. A negative control group of patients who did not receive any treatment was added (group 0). Totally, 1740 patients were included. Mean age was 63.04 ± 14.58 and 60.7% were males. The patients' distribution into the treatment groups was 604, 684, 169, 55, and 228 patients in groups 0-4, respectively, with a median survival of 3.61 ± 0.37, 11.10 ± 0.73, 57.41 ± 11.91, 52.30 ± 7.20, and 55.00 ± 9.19 months. The addition of chemotherapy, in any setting, to surgery provided an improved survival at 1 year (p = 0.006). This survival benefit ceased at the 2-, 3-, and 5-year checkpoints. The multivariate analysis identified age, sarcomatoid/biphasic histologies, nodal and distant metastasis, and offering no treatment or chemotherapy only as poor prognostic factors for overall survival. No difference in overall survival was noted with the addition of chemotherapy to complete debulking regardless of the timing. Complete debulking remains the standard treatment for MPM. The addition of systemic chemotherapy provides a short-term survival improvement at 1 year only and was similar whether given in the neoadjuvant or adjuvant setting. Nevertheless, it did not add a survival benefit beyond the 1-year time point.

'Enterprise risk management' essential for survival and sustainable development of micro, small and medium enterprises

OpenAIRE

Agrawal Reena

2016-01-01

The part that Micro, Small and Medium Enterprises (MSMEs) play, both in developed and developing countries, cannot be over emphasized and therefore their existence and survival is a matter of concern not only for the policy makers but also for the researchers. Large number of MSMEs die the same year that they are established. The current research was taken up to understand how MSMEs manage their risk and whether enterprise risk management is essential for survival and sustainable development ...

Evaluating time to cancer recurrence as a surrogate marker for survival from an information theory perspective.

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Alonso, Ariel; Molenberghs, Geert

2008-10-01

The last two decades have seen a lot of development in the area of surrogate marker validation. One of these approaches places the evaluation in a meta-analytic framework, leading to definitions in terms of trial- and individual-level association. A drawback of this methodology is that different settings have led to different measures at the individual level. Using information theory, Alonso et al. proposed a unified framework, leading to a new definition of surrogacy, which offers interpretational advantages and is applicable in a wide range of situations. In this work, we illustrate how this information-theoretic approach can be used to evaluate surrogacy when both endpoints are of a time-to-event type. Two meta-analyses, in early and advanced colon cancer, respectively, are then used to evaluate the performance of time to cancer recurrence as a surrogate for overall survival.

Patients with type 2 diabetes benefit from primary care-based disease management: a propensity score matched survival time analysis.

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Drabik, Anna; Büscher, Guido; Thomas, Karsten; Graf, Christian; Müller, Dirk; Stock, Stephanie

2012-08-01

This study aimed to assess the impact of a nationwide German diabetes mellitus disease management program (DMP) on survival time and costs in comparison to routine care. The authors conducted a retrospective observational cohort study using routine administration data from Germany's largest sickness fund to identify insured suffering from diabetes in 2002. A total of 95,443 insured with type 2 diabetes mellitus who were born before January 1, 1962 met the defined inclusion criteria, resulting in 19,888 pairs of DMP participants and nonparticipants matched for socioeconomic and health status using propensity score matching methods. This is the first time propensity score matching has been used to evaluate a survival benefit of DMPs. In the time frame analyzed (3 years), mean survival time for the DMP group was 1045 days vs. 985 days for the routine care group (Ptime. They also incurred lower costs compared to propensity score matched insured in routine care.

The number and microlocalization of tumor-associated immune cells are associated with patient's survival time in non-small cell lung cancer

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Dai, Fuqiang; Liu, Lunxu; Che, Guowei; Yu, Nanbin; Pu, Qiang; Zhang, Shangfu; Ma, Junliang; Ma, Lin; You, Zongbing

2010-01-01

Tumor microenvironment is composed of tumor cells, fibroblasts, endothelial cells, and infiltrating immune cells. Tumor-associated immune cells may inhibit or promote tumor growth and progression. This study was conducted to determine whether the number and microlocalization of macrophages, mature dendritic cells and cytotoxic T cells in non-small cell lung cancer are associated with patient's survival time. Ninety-nine patients with non-small cell lung cancer (NSCLC) were included in this retrospective study. Paraffin-embedded NSCLC specimens and their clinicopathological data including up to 8-year follow-up information were used. Immunohistochemical staining for CD68 (marker for macrophages), CD83 (marker for mature dendritic cells), and CD8 (marker for cytotoxic T cells) was performed and evaluated in a blinded fashion. The numbers of immune cells in tumor islets and stroma, tumor islets, or tumor stroma were counted under a microscope. Correlation of the cell numbers and patient's survival time was analyzed using the Statistical Package for the Social Sciences (version 13.0). The numbers of macrophages, mature dendritic cells and cytotoxic T cells were significantly more in the tumor stroma than in the tumor islets. The number of macrophages in the tumor islets was positively associated with patient's survival time, whereas the number of macrophages in the tumor stroma was negatively associated with patient's survival time in both univariate and multivariate analyses. The number of mature dendritic cells in the tumor islets and stroma, tumor islets only, or tumor stroma only was positively associated with patient's survival time in a univariate analysis but not in a multivariate analysis. The number of cytotoxic T cells in the tumor islets and stroma was positively associated with patient's survival time in a univariate analysis but not in a multivariate analysis. The number of cytotoxic T cells in the tumor islets only or stroma

Caregiver behavior change for child survival and development in low- and middle-income countries: an examination of the evidence.

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Elder, John P; Pequegnat, Willo; Ahmed, Saifuddin; Bachman, Gretchen; Bullock, Merry; Carlo, Waldemar A; Chandra-Mouli, Venkatraman; Fox, Nathan A; Harkness, Sara; Huebner, Gillian; Lombardi, Joan; Murry, Velma McBride; Moran, Allisyn; Norton, Maureen; Mulik, Jennifer; Parks, Will; Raikes, Helen H; Smyser, Joseph; Sugg, Caroline; Sweat, Michael; Ulkuer, Nurper

2014-01-01

In June of 2012, representatives from more than 80 countries promulgated a Child Survival Call to Action, which called for reducing child mortality to 20 or fewer child deaths per 1,000 live births in every country by 2035. To address the problem of ending preventable child deaths, the U.S. Agency for International Development and the United Nations Children's Fund convened, on June 3-4, 2013, an Evidence Summit on Enhancing Child Survival and Development in Lower- and Middle-Income Countries by Achieving Population-Level Behavior Change. Six evidence review teams were established on different topics related to child survival and healthy development to identify the relevant evidence-based interventions and to prepare reports. This article was developed by the evidence review team responsible for identifying the research literature on caregiver change for child survival and development. This article is organized into childhood developmental periods and cross-cutting issues that affect child survival and healthy early development across all these periods. On the basis of this review, the authors present evidence-based recommendations for programs focused on caregivers to increase child survival and promote healthy development. Last, promising directions for future research to change caregivers' behaviors are given.

Risk-adjusted survival for adults following in-hospital cardiac arrest by day of week and time of day: observational cohort study.

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Robinson, Emily J; Smith, Gary B; Power, Geraldine S; Harrison, David A; Nolan, Jerry; Soar, Jasmeet; Spearpoint, Ken; Gwinnutt, Carl; Rowan, Kathryn M

2016-11-01

Internationally, hospital survival is lower for patients admitted at weekends and at night. Data from the UK National Cardiac Arrest Audit (NCAA) indicate that crude hospital survival was worse after in-hospital cardiac arrest (IHCA) at night versus day, and at weekends versus weekdays, despite similar frequency of events. To describe IHCA demographics during three day/time periods-weekday daytime (Monday to Friday, 08:00 to 19:59), weekend daytime (Saturday and Sunday, 08:00 to 19:59) and night-time (Monday to Sunday, 20:00 to 07:59)-and to compare the associated rates of return of spontaneous circulation (ROSC) for >20 min (ROSC>20 min) and survival to hospital discharge, adjusted for risk using previously developed NCAA risk models. To consider whether any observed difference could be attributed to differences in the case mix of patients resident in hospital and/or the administered care. We performed a prospectively defined analysis of NCAA data from 27 700 patients aged ≥16 years receiving chest compressions and/or defibrillation and attended by a hospital-based resuscitation team in response to a resuscitation (2222) call in 146 UK acute hospitals. Risk-adjusted outcomes (OR (95% CI)) were worse (p20 min 0.88 (0.81 to 0.95); hospital survival 0.72 (0.64 to 0.80)), and night-time (ROSC>20 min 0.72 (0.68 to 0.76); hospital survival 0.58 (0.54 to 0.63)) compared with weekday daytime. The effects were stronger for non-shockable than shockable rhythms, but there was no significant interaction between day/time of arrest and age, or day/time of arrest and arrest location. While many daytime IHCAs involved procedures, restricting the analyses to IHCAs in medical admissions with an arrest location of ward produced results that are broadly in line with the primary analyses. IHCAs attended by the hospital-based resuscitation team during nights and weekends have substantially worse outcomes than during weekday daytimes. Organisational or care differences at

Modeling nest-survival data: a comparison of recently developed methods that can be implemented in MARK and SAS

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Rotella, J. J.

2004-06-01

Full Text Available Estimating nest success and evaluating factors potentially related to the survival rates of nests are key aspects of many studies of avian populations. A strong interest in nest success has led to a rich literature detailing a variety of estimation methods for this vital rate. In recent years, modeling approaches have undergone especially rapid development. Despite these advances, most researchers still employ Mayfield’s ad-hoc method (Mayfield, 1961 or, in some cases, the maximum-likelihood estimator of Johnson (1979 and Bart & Robson (1982. Such methods permit analyses of stratified data but do not allow for more complex and realistic models of nest survival rate that include covariates that vary by individual, nest age, time, etc. and that may be continuous or categorical. Methods that allow researchers to rigorously assess the importance of a variety of biological factors that might affect nest survival rates can now be readily implemented in Program MARK and in SAS’s Proc GENMOD and Proc NLMIXED. Accordingly, use of Mayfield’s estimator without first evaluating the need for more complex models of nest survival rate cannot be justified. With the goal of increasing the use of more flexible methods, we first describe the likelihood used for these models and then consider the question of what the effective sample size is for computation of AICc. Next, we consider the advantages and disadvantages of these different programs in terms of ease of data input and model construction; utility/flexibility of generated estimates and predictions; ease of model selection; and ability to estimate variance components. An example data set is then analyzed using both MARK and SAS to demonstrate implementation of the methods with various models that contain nest-, group- (or block-, and time-specific covariates. Finally, we discuss improvements that would, if they became available, promote a better general understanding of nest survival rates.

Rigorous bounds on survival times in circular accelerators and efficient computation of fringe-field transfer maps

International Nuclear Information System (INIS)

Hoffstaetter, G.H.

1994-12-01

Analyzing stability of particle motion in storage rings contributes to the general field of stability analysis in weakly nonlinear motion. A method which we call pseudo invariant estimation (PIE) is used to compute lower bounds on the survival time in circular accelerators. The pseudeo invariants needed for this approach are computed via nonlinear perturbative normal form theory and the required global maxima of the highly complicated multivariate functions could only be rigorously bound with an extension of interval arithmetic. The bounds on the survival times are large enough to the relevant; the same is true for the lower bounds on dynamical aperatures, which can be computed. The PIE method can lead to novel design criteria with the objective of maximizing the survival time. A major effort in the direction of rigourous predictions only makes sense if accurate models of accelerators are available. Fringe fields often have a significant influence on optical properties, but the computation of fringe-field maps by DA based integration is slower by several orders of magnitude than DA evaluation of the propagator for main-field maps. A novel computation of fringe-field effects called symplectic scaling (SYSCA) is introduced. It exploits the advantages of Lie transformations, generating functions, and scaling properties and is extremely accurate. The computation of fringe-field maps is typically made nearly two orders of magnitude faster. (orig.)

Caregiver Behavior Change for Child Survival and Development in Low- and Middle-Income Countries: An Examination of the Evidence

Science.gov (United States)

Elder, John P.; Pequegnat, Willo; Ahmed, Saifuddin; Bachman, Gretchen; Bullock, Merry; Carlo, Waldemar A.; Chandra-Mouli, Venkatraman; Fox, Nathan A.; Harkness, Sara; Huebner, Gillian; Lombardi, Joan; Murry, Velma McBride; Moran, Allisyn; Norton, Maureen; Mulik, Jennifer; Parks, Will; Raikes, Helen H.; Smyser, Joseph; Sugg, Caroline; Sweat, Michael

2014-01-01

In June of 2012, representatives from more than 80 countries promulgated a Child Survival Call to Action, which called for reducing child mortality to 20 or fewer child deaths per 1,000 live births in every country by 2035. To address the problem of ending preventable child deaths, the U.S. Agency for International Development and the United Nations Children's Fund convened, on June 3–4, 2013, an Evidence Summit on Enhancing Child Survival and Development in Lower- and Middle-Income Countries by Achieving Population-Level Behavior Change. Six evidence review teams were established on different topics related to child survival and healthy development to identify the relevant evidence-based interventions and to prepare reports. This article was developed by the evidence review team responsible for identifying the research literature on caregiver change for child survival and development. This article is organized into childhood developmental periods and cross-cutting issues that affect child survival and healthy early development across all these periods. On the basis of this review, the authors present evidence-based recommendations for programs focused on caregivers to increase child survival and promote healthy development. Last, promising directions for future research to change caregivers' behaviors are given. PMID:25315597

Consequences of cold-ischemia time on primary nonfunction and patient and graft survival in liver transplantation: a meta-analysis.

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James E Stahl

2008-06-01

Full Text Available The ability to preserve organs prior to transplant is essential to the organ allocation process.The purpose of this study is to describe the functional relationship between cold-ischemia time (CIT and primary nonfunction (PNF, patient and graft survival in liver transplant.To identify relevant articles Medline, EMBASE and the Cochrane database, including the non-English literature identified in these databases, was searched from 1966 to April 2008. Two independent reviewers screened and extracted the data. CIT was analyzed both as a continuous variable and stratified by clinically relevant intervals. Nondichotomous variables were weighted by sample size. Percent variables were weighted by the inverse of the binomial variance.Twenty-six studies met criteria. Functionally, PNF% = -6.678281+0.9134701*CIT Mean+0.1250879*(CIT Mean-9.895352-0.0067663*(CIT Mean-9.895353, r2 = .625, , p<.0001. Mean patient survival: 93% (1 month, 88% (3 months, 83% (6 months and 83% (12 months. Mean graft survival: 85.9% (1 month, 80.5% (3 months, 78.1% (6 months and 76.8% (12 months. Maximum patient and graft survival occurred with CITs between 7.5-12.5 hrs at each survival interval. PNF was also significantly correlated with ICU time, % first time grafts and % immunologic mismatches.The results of this work imply that CIT may be the most important pre-transplant information needed in the decision to accept an organ.

CT texture features of liver parenchyma for predicting development of metastatic disease and overall survival in patients with colorectal cancer.

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Lee, Scott J; Zea, Ryan; Kim, David H; Lubner, Meghan G; Deming, Dustin A; Pickhardt, Perry J

2018-04-01

To determine if identifiable hepatic textural features are present at abdominal CT in patients with colorectal cancer (CRC) prior to the development of CT-detectable hepatic metastases. Four filtration-histogram texture features (standard deviation, skewness, entropy and kurtosis) were extracted from the liver parenchyma on portal venous phase CT images at staging and post-treatment surveillance. Surveillance scans corresponded to the last scan prior to the development of CT-detectable CRC liver metastases in 29 patients (median time interval, 6 months), and these were compared with interval-matched surveillance scans in 60 CRC patients who did not develop liver metastases. Predictive models of liver metastasis-free survival and overall survival were built using regularised Cox proportional hazards regression. Texture features did not significantly differ between cases and controls. For Cox models using all features as predictors, all coefficients were shrunk to zero, suggesting no association between any CT texture features and outcomes. Prognostic indices derived from entropy features at surveillance CT incorrectly classified patients into risk groups for future liver metastases (p < 0.001). On surveillance CT scans immediately prior to the development of CRC liver metastases, we found no evidence suggesting that changes in identifiable hepatic texture features were predictive of their development. • No correlation between liver texture features and metastasis-free survival was observed. • Liver texture features incorrectly classified patients into risk groups for liver metastases. • Standardised texture analysis workflows need to be developed to improve research reproducibility.

The Impact of Timing and Graft Dysfunction on Survival and Cardiac Allograft Vasculopathy in Antibody Mediated Rejection

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Clerkin, Kevin J.; Restaino, Susan W.; Zorn, Emmanuel; Vasilescu, Elena R.; Marboe, Charles C.; Mancini, Donna M.

2017-01-01

Background Antibody mediated rejection (AMR) has been associated with increased mortality and cardiac allograft vasculopathy (CAV). Early studies suggested that late AMR was rarely associated with graft dysfunction while recent reports have demonstrated an association with increased mortality. We sought to investigate the timing of AMR and its association with graft dysfunction, mortality, and CAV. Methods This retrospective cohort study identified all adult heart transplant recipients at Columbia University Medical Center from 2004–2013 (689 patients). There were 68 primary cases of AMR, which were stratified by early (1-year post-OHT) AMR. Kaplan-Meier survival analysis and modeling was performed with multivariable logistic regression and Cox proportional hazards regression. Results From January 1, 2004 through October 1, 2015 43 patients had early AMR (median 23 days post-OHT) and 25 had late AMR (median 1084 days post-OHT). Graft dysfunction was less common with early compared with late AMR (25.6% vs. 56%, p=0.01). Patients with late AMR had decreased post-AMR survival compared with early AMR (1-year 80% vs. 93%, 5-year 51% vs. 73%, p<0.05). When stratified by graft dysfunction, only those with late AMR and graft dysfunction had worse survival (30-day 79%, 1-year 64%, and 5-year 36%, p<0.006). The association remained irrespective of age, sex, DSA, LVAD use, reason for OHT, and recovery of graft function. Similarly, those with late AMR and graft dysfunction had accelerated development of de-novo CAV (50% at 1 year, HR 5.42, p=0.009), while all other groups were all similar to the general transplant population. Conclusion Late AMR is frequently associated with graft dysfunction. When graft dysfunction is present in late AMR there is an early and sustained increased risk of mortality and rapid development of de-novo CAV despite aggressive treatment. PMID:27423693

Vitamin D Depletion in Pregnancy Decreases Survival Time, Oxygen Saturation, Lung Weight and Body Weight in Preterm Rat Offspring.

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Sine Lykkedegn

Full Text Available Animal studies suggest a role of vitamin D in fetal lung development although not studied in preterm animals. We tested the hypothesis that vitamin D depletion aggravates respiratory insufficiency in preterm rat offspring. Furthermore, the effects of vitamin D depletion on growth and lung surfactant were investigated. Female Sprague-Dawley rats were randomly assigned low vitamin D (VDL or control diet before mating and followed with serum 25-hydroxyvitamin D (s-25(OHD determinations. After cesarean section at gestational day 19 (E19 or day 22 (E22, placental weight, birth weight, crown-rump-length (CRL, oxygenation (SaO2 at 30 min and survival time were recorded. The pup lungs were analyzed for phospholipid levels, surfactant protein A-D mRNA and the expression of the vitamin D receptor (VDR. S-25(OHD was significantly lower in the VDL group at cesarean section (12 vs. 30nmol/L, p<0.0001. Compared to the controls, E19 VDL pups had lower birth weight (2.13 vs. 2.29g, p<0.001, lung weight (0.09 vs. 0.10g, p = 0.002, SaO2 (54% vs. 69%, p = 0.002 as well as reduced survival time (0.50 vs. 1.25h, p<0.0001. At E22, the VDL-induced pulmonary differences were leveled out, but VDL pups had lower CRL (4.0 vs. 4.5cm, p<0.0001. The phospholipid levels and the surfactant protein mRNA expression did not differ between the dietary groups. In conclusion, Vitamin D depletion led to lower oxygenation and reduced survival time in the preterm offspring, associated with reduced lung weight and birth weight. Further studies of vitamin D depletion in respiratory insufficiency in preterm neonates are warranted.

Timing of adjuvant chemotherapy and its relation to survival among patients with stage III colon cancer.

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Bos, A C R K; van Erning, F N; van Gestel, Y R B M; Creemers, G J M; Punt, C J A; van Oijen, M G H; Lemmens, V E P P

2015-11-01

Currently available data suggest that delaying the start of adjuvant chemotherapy in colon cancer patients has a detrimental effect on survival. We analysed which factors impact on the timing of adjuvant chemotherapy and evaluated the influence on overall survival (OS). Stage III colon cancer patients who underwent resection and received adjuvant chemotherapy between 2008 and 2013 were selected from the Netherlands Cancer Registry. Timing of adjuvant chemotherapy was subdivided into: ⩽ 4, 5-6, 7-8, 9-10, 11-12 and 13-16 weeks post-surgery. Multivariable regressions were performed to assess the influence of several factors on the probability of starting treatment within 8 weeks post-surgery and to evaluate the association of timing of adjuvant chemotherapy with 5-year OS. 6620 patients received adjuvant chemotherapy, 14% commenced after 8 weeks. Factors associated with starting treatment after 8 weeks were older age (Odds ratio (OR) 65-74 versus colon cancer patients within 8 weeks post-surgery. Copyright © 2015 Elsevier Ltd. All rights reserved.

Network survivability performance

Science.gov (United States)

1993-11-01

This technical report has been developed to address the survivability of telecommunications networks including services. It responds to the need for a common understanding of, and assessment techniques for network survivability, availability, integrity, and reliability. It provides a basis for designing and operating telecommunications networks to user expectations for network survivability and a foundation for continuing industry activities in the subject area. This report focuses on the survivability of both public and private networks and covers a wide range of users. Two frameworks are established for quantifying and categorizing service outages, and for classifying network survivability techniques and measures. The performance of the network survivability techniques is considered; however, recommended objectives are not established for network survivability performance.

Effect of intestinal microflora on the survival time of mice exposed to lethal whole-body. gamma. irradiation

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Onoue, M.; Uchida, K.; Yokokura, T.; Takahashi, T.; Mutai, M.

1981-11-01

The effect of intestinal microflora on the survival time of mice exposed to 2-kR whole-body ..gamma.. irradiation was studied using germfree, monoassociated, and conventionalized ICR mice. The germfree mice were monoassociated with 1 of 11 bacterial strains, which were isolated from the fresh feces of conventional mice, 2 weeks prior to irradiation. All mice died within 3 weeks after irradiation. Monoassociation with Fusobacterium sp., Streptococcus faecalis, Escherichia coli, or Pseudomonas sp. significantly reduced the mean survival time compared to that of germfree mice. In contrast, monoassociation with Clostridium sp., Bifidobacterium pseudolongum, or Lactobacillus acidophilus significantly prolonged the mean survival time compared to that of germfree mice. This suggests that the latter organisms may perform some activity to protect the mice from radiation injury. In this histopathological autopsy examination, the main lesions were hypocellularity in hematopoietic organs and hemorrhage in various organs. Neither karyorrhexis nor desquamation of intestinal mucosal cells was observed in any mice. From these observations, it is suggested that the death of these mice was related to hematopoietic damage. Bacterial invasion into various organs was observed in conventionalized and Pseudomonas-, E. coli-, or S. faecalis-monoassociated mice but not in Clostridium-, B. pseudolongum-, L. acidophilus-, or Fusobacterium-monoassociated mice.

Effect of intestinal microflora on the survival time of mice exposed to lethal whole-body γ irradiation

International Nuclear Information System (INIS)

Onoue, M.; Uchida, K.; Yokokura, T.; Takahashi, T.; Mutai, M.

1981-01-01

The effect of intestinal microflora on the survival time of mice exposed to 2-kR whole-body γ irradiation was studied using germfree, monoassociated, and conventionalized ICR mice. The germfree mice were monoassociated with 1 of 11 bacterial strains, which were isolated from the fresh feces of conventional mice, 2 weeks prior to irradiation. All mice died within 3 weeks after irradiation. Monoassociation with Fusobacterium sp., Streptococcus faecalis, Escherichia coli, or Pseudomonas sp. significantly reduced the mean survival time compared to that of germfree mice. In contrast, monoassociation with Clostridium sp., Bifidobacterium pseudolongum, or Lactobacillus acidophilus significantly prolonged the mean survival time compared to that of germfree mice. This suggests that the latter organisms may perform some activity to protect the mice from radiation injury. In this histopathological autopsy examination, the main lesions were hypocellularity in hematopoietic organs and hemorrhage in various organs. Neither karyorrhexis nor desquamation of intestinal mucosal cells was observed in any mice. From these observations, it is suggested that the death of these mice was related to hematopoietic damage. Bacterial invasion into various organs was observed in conventionalized and Pseudomonas-, E. coli-, or S. faecalis-monoassociated mice but not in Clostridium-, B. pseudolongum-, L. acidophilus-, or Fusobacterium-monoassociated mice

Long time to diagnosis of medulloblastoma in children is not associated with decreased survival or with worse neurological outcome.

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Jean-Francois Brasme

Full Text Available BACKGROUND: The long time to diagnosis of medulloblastoma, one of the most frequent brain tumors in children, is the source of painful remorse and sometimes lawsuits. We analyzed its consequences for tumor stage, survival, and sequelae. PATIENTS AND METHODS: This retrospective population-based cohort study included all cases of pediatric medulloblastoma from a region of France between 1990 and 2005. We collected the demographic, clinical, and tumor data and analyzed the relations between the interval from symptom onset until diagnosis, initial disease stage, survival, and neuropsychological and neurological outcome. RESULTS: The median interval from symptom onset until diagnosis for the 166 cases was 65 days (interquartile range 31-121, range 3-457. A long interval (defined as longer than the median was associated with a lower frequency of metastasis in the univariate and multivariate analyses and with a larger tumor volume, desmoplastic histology, and longer survival in the univariate analysis, but not after adjustment for confounding factors. The time to diagnosis was significantly associated with IQ score among survivors. No significant relation was found between the time to diagnosis and neurological disability. In the 62 patients with metastases, a long prediagnosis interval was associated with a higher T stage, infiltration of the fourth ventricle floor, and incomplete surgical resection; it nonetheless did not influence survival significantly in this subgroup. CONCLUSIONS: We found complex and often inverse relations between time to diagnosis of medulloblastoma in children and initial severity factors, survival, and neuropsychological and neurological outcome. This interval appears due more to the nature of the tumor and its progression than to parental or medical factors. These conclusions should be taken into account in the information provided to parents and in expert assessments produced for malpractice claims.

Assessing development assistance for child survival between 2000 and 2014: A multi-sectoral perspective.

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Lu, Chunling; Chu, Annie; Li, Zhihui; Shen, Jian; Subramanian, S V; Hill, Kenneth

2017-01-01

The majority of Countdown countries did not reach the fourth Millennium Development Goal (MDG 4) on reducing child mortality, despite the fact that donor funding to the health sector has drastically increased. When tracking aid invested in child survival, previous studies have exclusively focused on aid targeting reproductive, maternal, newborn, and child health (RMNCH). We take a multi-sectoral approach and extend the estimation to the four sectors that determine child survival: health (RMNCH and non-RMNCH), education, water and sanitation, and food and humanitarian assistance (Food/HA). Using donor reported data, obtained mainly from the OECD Creditor Reporting System and Development Assistance Committee, we tracked the level and trends of aid (in grants or loans) disbursed to each of the four sectors at the global, regional, and country levels. We performed detailed analyses on missing data and conducted imputation with various methods. To identify aid projects for RMNCH, we developed an identification strategy that combined keyword searches and manual coding. To quantify aid for RMNCH in projects with multiple purposes, we adopted an integrated approach and produced the lower and upper bounds of estimates for RMNCH, so as to avoid making assumptions or using weak evidence for allocation. We checked the sensitivity of trends to the estimation methods and compared our estimates to that produced by other studies. Our study yielded time-series and recipient-specific annual estimates of aid disbursed to each sector, as well as their lower- and upper-bounds in 134 countries between 2000 and 2014, with a specific focus on Countdown countries. We found that the upper-bound estimates of total aid disbursed to the four sectors in 134 countries rose from US$ 22.62 billion in 2000 to US$ 59.29 billion in 2014, with the increase occurring in all income groups and regions with sub-Saharan Africa receiving the largest sum. Aid to RMNCH has experienced the fastest growth (12

Assessing development assistance for child survival between 2000 and 2014: A multi-sectoral perspective.

Directory of Open Access Journals (Sweden)

Chunling Lu

Full Text Available The majority of Countdown countries did not reach the fourth Millennium Development Goal (MDG 4 on reducing child mortality, despite the fact that donor funding to the health sector has drastically increased. When tracking aid invested in child survival, previous studies have exclusively focused on aid targeting reproductive, maternal, newborn, and child health (RMNCH. We take a multi-sectoral approach and extend the estimation to the four sectors that determine child survival: health (RMNCH and non-RMNCH, education, water and sanitation, and food and humanitarian assistance (Food/HA.Using donor reported data, obtained mainly from the OECD Creditor Reporting System and Development Assistance Committee, we tracked the level and trends of aid (in grants or loans disbursed to each of the four sectors at the global, regional, and country levels. We performed detailed analyses on missing data and conducted imputation with various methods. To identify aid projects for RMNCH, we developed an identification strategy that combined keyword searches and manual coding. To quantify aid for RMNCH in projects with multiple purposes, we adopted an integrated approach and produced the lower and upper bounds of estimates for RMNCH, so as to avoid making assumptions or using weak evidence for allocation. We checked the sensitivity of trends to the estimation methods and compared our estimates to that produced by other studies. Our study yielded time-series and recipient-specific annual estimates of aid disbursed to each sector, as well as their lower- and upper-bounds in 134 countries between 2000 and 2014, with a specific focus on Countdown countries. We found that the upper-bound estimates of total aid disbursed to the four sectors in 134 countries rose from US$ 22.62 billion in 2000 to US$ 59.29 billion in 2014, with the increase occurring in all income groups and regions with sub-Saharan Africa receiving the largest sum. Aid to RMNCH has experienced the

What affects local community hospitals' survival in turbulent times?

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Chiang, Hung-Che; Wang, Shiow-Ing

2015-06-01

Hospital closures became a prevalent phenomenon in Taiwan after the implementation of a national health insurance program. A wide range of causes contributes to the viability of hospitals, but little is known about the situation under universal coverage health systems. The purpose of present study is to recognize the factors that may contribute to hospital survival under the universal coverage health system. This is a retrospective case-control study. Local community hospitals that contracted with the Bureau of National Health Insurance in 1998 and remained open during the period 1998-2011 are the designated cases. Controls are local community hospitals that closed during the same period. Using longitudinal representative health claim data, 209 local community hospitals that closed during 1998-2011 were compared with 165 that remained open. Variables related to institutional characteristics, degree of competition, characteristics of patients and financial performance were analyzed by logistic regression models. Hospitals' survival was positively related to specialty hospital, the number of respiratory care beds, the physician to population ratio, the number of clinics in the same region, a highly competitive market and the occupancy rate of elderly patients in the hospital. Teaching hospitals, investor-owned hospitals, the provision of obstetrics services or home care, and the number of medical centers or other local community hospitals may jeopardize the chance of survival. Factors-enhanced local hospitals to survive under the universal coverage health system have been identified. Hospital managers could manipulate these findings and adapt strategies for subsistence. © The Author 2015. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.

C. elegans AMPKs promote survival and arrest germline development during nutrient stress

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Masamitsu Fukuyama

2012-08-01

Mechanisms controlling development, growth, and metabolism are coordinated in response to changes in environmental conditions, enhancing the likelihood of survival to reproductive maturity. Much remains to be learned about the molecular basis underlying environmental influences on these processes. C. elegans larvae enter a developmentally dormant state called L1 diapause when hatched into nutrient-poor conditions. The nematode pten homologue daf-18 is essential for maintenance of survival and germline stem cell quiescence during this period (Fukuyama et al., 2006; Sigmond et al., 2008, but the details of the signaling network(s in which it functions remain to be elucidated. Here, we report that animals lacking both aak-1 and aak-2, which encode the two catalytic α subunits of AMP-activated protein kinase (AMPK, show reduced viability and failure to maintain mitotic quiescence in germline stem cells during L1 diapause. Furthermore, failure to arrest germline proliferation has a long term consequence; aak double mutants that have experienced L1 diapause develop into sterile adults when returned to food, whereas their continuously fed siblings are fertile. Both aak and daf-18 appear to maintain germline quiescence by inhibiting activity of the common downstream target, TORC1 (TOR Complex 1. In contrast, rescue of the lethality phenotype indicates that aak-2 acts not only in the intestine, as does daf-18, but also in neurons, likely promoting survival by preventing energy deprivation during L1 diapause. These results not only provide evidence that AMPK contributes to survival during L1 diapause in a manner distinct from that by which it controls dauer diapause, but they also suggest that AMPK suppresses TORC1 activity to maintain stem cell quiescence.

Larval food quantity affects development time, survival and adult biological traits that influence the vectorial capacity of Anopheles darlingi under laboratory conditions.

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Araújo, Maisa da-Silva; Gil, Luiz Herman S; e-Silva, Alexandre de-Almeida

2012-08-02

The incidence of malaria in the Amazon is seasonal and mosquito vectorial capacity parameters, including abundance and longevity, depend on quantitative and qualitative aspects of the larval diet. Anopheles darlingi is a major malaria vector in the Amazon, representing >95% of total Anopheles population present in the Porto Velho region. Despite its importance in the transmission of the Plasmodium parasite, knowledge of the larval biology and ecology is limited. Studies regarding aspects of adult population ecology are more common than studies on larval ecology. However, in order develop effective control strategies and laboratory breeding conditions for this species, more data on the factors affecting vector biology is needed. The aim of the present study is to assess the effects of larval food quantity on the vectorial capacity of An. darling under laboratory conditions. Anopheles darlingi was maintained at 28°C, 80% humidity and exposed to a daily photoperiod of 12 h. Larvae were divided into three experimental groups that were fed either a low, medium, or high food supply (based on the food amounts consumed by other species of culicids). Each experiment was replicated for six times. A cohort of adults were also exposed to each type of diet and assessed for several biological characteristics (e.g. longevity, bite frequency and survivorship), which were used to estimate the vectorial capacity of each experimental group. The group supplied with higher food amounts observed a reduction in development time while larval survival increased. In addition to enhanced longevity, increasing larval food quantity was positively correlated with increasing frequency of bites, longer blood meal duration and wing length, resulting in greater vectorial capacity. However, females had greater longevity than males despite having smaller wings. Overall, several larval and adult biological traits were significantly affected by larval food availability. Greater larval food supply

Biostatistics series module 9: Survival analysis

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Avijit Hazra

2017-01-01

Full Text Available Survival analysis is concerned with “time to event“ data. Conventionally, it dealt with cancer death as the event in question, but it can handle any event occurring over a time frame, and this need not be always adverse in nature. When the outcome of a study is the time to an event, it is often not possible to wait until the event in question has happened to all the subjects, for example, until all are dead. In addition, subjects may leave the study prematurely. Such situations lead to what is called censored observations as complete information is not available for these subjects. The data set is thus an assemblage of times to the event in question and times after which no more information on the individual is available. Survival analysis methods are the only techniques capable of handling censored observations without treating them as missing data. They also make no assumption regarding normal distribution of time to event data. Descriptive methods for exploring survival times in a sample include life table and Kaplan–Meier techniques as well as various kinds of distribution fitting as advanced modeling techniques. The Kaplan–Meier cumulative survival probability over time plot has become the signature plot for biomedical survival analysis. Several techniques are available for comparing the survival experience in two or more groups – the log-rank test is popularly used. This test can also be used to produce an odds ratio as an estimate of risk of the event in the test group; this is called hazard ratio (HR. Limitations of the traditional log-rank test have led to various modifications and enhancements. Finally, survival analysis offers different regression models for estimating the impact of multiple predictors on survival. Cox's proportional hazard model is the most general of the regression methods that allows the hazard function to be modeled on a set of explanatory variables without making restrictive assumptions concerning the

Conditional survival is greater than overall survival at diagnosis in patients with osteosarcoma and Ewing's sarcoma.

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Miller, Benjamin J; Lynch, Charles F; Buckwalter, Joseph A

2013-11-01

Conditional survival is a measure of the risk of mortality given that a patient has survived a defined period of time. These estimates are clinically helpful, but have not been reported previously for osteosarcoma or Ewing's sarcoma. We determined the conditional survival of patients with osteosarcoma and Ewing's sarcoma given survival of 1 or more years. We used the Surveillance, Epidemiology, and End Results (SEER) Program database to investigate cases of osteosarcoma and Ewing's sarcoma in patients younger than 40 years from 1973 to 2009. The SEER Program is managed by the National Cancer Institute and provides survival data gathered from population-based cancer registries. We used an actuarial life table analysis to determine any cancer cause-specific 5-year survival estimates conditional on 1 to 5 years of survival after diagnosis. We performed a similar analysis to determine 20-year survival from the time of diagnosis. The estimated 5-year survival improved each year after diagnosis. For local/regional osteosarcoma, the 5-year survival improved from 74.8% at baseline to 91.4% at 5 years-meaning that if a patient with localized osteosarcoma lives for 5 years, the chance of living for another 5 years is 91.4%. Similarly, the 5-year survivals for local/regional Ewing's sarcoma improved from 72.9% at baseline to 92.5% at 5 years, for metastatic osteosarcoma 35.5% at baseline to 85.4% at 5 years, and for metastatic Ewing's sarcoma 31.7% at baseline to 83.6% at 5 years. The likelihood of 20-year cause-specific survival from the time of diagnosis in osteosarcoma and Ewing's sarcoma was almost 90% or greater after 10 years of survival, suggesting that while most patients will remain disease-free indefinitely, some experience cancer-related complications years after presumed eradication. The 5-year survival estimates of osteosarcoma and Ewing's sarcoma improve with each additional year of patient survival. Knowledge of a changing risk profile is useful in counseling

Effects of fine sediment, hyporheic flow, and spawning site characteristics on survival and development of bull trout embryos

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Bowerman, Tracy; Neilson, Bethany; Budy, Phaedra

2014-01-01

Successful spawning is imperative for the persistence of salmonid populations, but relatively little research has been conducted to evaluate factors affecting early life-stage survival for bull trout (Salvelinus confluentus), a threatened char. We conducted a field experiment to assess the relationship between site-specific environmental factors and bull trout embryo survival and fry emergence timing. Survival from egg to hatch was negatively related to percent fine sediment (bull trout egg survival, but early life-stage success may ultimately be limited by intrusion of fine sediment into the incubation environment.

Monte Carlo model to simulate the effects of DNA damage resulting from accumulation of 125I decays during development of colonies and clonogenic survival assays

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Lobachevsky, P.; Karagiannis, T.; Martin, R.F.

1998-01-01

Full text: Exposure of cultured cells to an internal source of ionising radiation, such as a radioactive isotope, differs substantially from external irradiation in the determination of delivered dose. In some cases, the radioactive isotope cannot be quickly and completely removed from cells before plating for clonogenic survival assay. This provides an additional dose of irradiation which is not easy to calculate. The contribution of this phenomenon to the cell survival is especially important if a radioactive isotope is incorporated into DNA, or a DNA-binding ligand is labelled with the isotope. The correction of the cell survival due to additional dose cannot be calculated using a simple analytical expression, since the isotope is present in the cells during colony growth. We have developed a Monte Carlo model which simulates the process of the colony growth, and takes into account the extent of damage from isotope decays accumulated between consequent cell divisions. The model considers such factors as cell cycle time, radiosensitivity, colony growth inhibition, isotope specific (per cell) activity, partition of isotope in daughter cells, isotope half-life time, isotope efflux. The model allows estimation of the impact of the irradiation during colony formation on the distribution of colony size, and on the calculation of the survival correction factor, which depends mainly on the isotope cell-specific activity. We applied the model to interpret the difference in survival of K652 cells exposed to 125 I decays with various cell-specific activities: 0.45, 3.21 and 7.42 decays/cell/hour. The cells were treated with 125 I - labelled Hoechst 33258 which binds to DNA in cell nucleus. After accumulation of 125 I decays under non-growth conditions, cells were plated for clonogenic survival assay. The survival correction factors calculated from the model for the given values of 125 I cell-specific activity are in good correlation with differences between experimental

Survival Analysis of Patients with End Stage Renal Disease

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Urrutia, J. D.; Gayo, W. S.; Bautista, L. A.; Baccay, E. B.

2015-06-01

This paper provides a survival analysis of End Stage Renal Disease (ESRD) under Kaplan-Meier Estimates and Weibull Distribution. The data were obtained from the records of V. L. MakabaliMemorial Hospital with respect to time t (patient's age), covariates such as developed secondary disease (Pulmonary Congestion and Cardiovascular Disease), gender, and the event of interest: the death of ESRD patients. Survival and hazard rates were estimated using NCSS for Weibull Distribution and SPSS for Kaplan-Meier Estimates. These lead to the same conclusion that hazard rate increases and survival rate decreases of ESRD patient diagnosed with Pulmonary Congestion, Cardiovascular Disease and both diseases with respect to time. It also shows that female patients have a greater risk of death compared to males. The probability risk was given the equation R = 1 — e-H(t) where e-H(t) is the survival function, H(t) the cumulative hazard function which was created using Cox-Regression.

SURVIVAL ANALYSIS AND LENGTH-BIASED SAMPLING

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Masoud Asgharian

2010-12-01

Full Text Available When survival data are colleted as part of a prevalent cohort study, the recruited cases have already experienced their initiating event. These prevalent cases are then followed for a fixed period of time at the end of which the subjects will either have failed or have been censored. When interests lies in estimating the survival distribution, from onset, of subjects with the disease, one must take into account that the survival times of the cases in a prevalent cohort study are left truncated. When it is possible to assume that there has not been any epidemic of the disease over the past period of time that covers the onset times of the subjects, one may assume that the underlying incidence process that generates the initiating event times is a stationary Poisson process. Under such assumption, the survival times of the recruited subjects are called “lengthbiased”. I discuss the challenges one is faced with in analyzing these type of data. To address the theoretical aspects of the work, I present asymptotic results for the NPMLE of the length-biased as well as the unbiased survival distribution. I also discuss estimating the unbiased survival function using only the follow-up time. This addresses the case that the onset times are either unknown or known with uncertainty. Some of our most recent work and open questions will be presented. These include some aspects of analysis of covariates, strong approximation, functional LIL and density estimation under length-biased sampling with right censoring. The results will be illustrated with survival data from patients with dementia, collected as part of the Canadian Study of Health and Aging (CSHA.

Progression-free survival/time to progression as a potential surrogate for overall survival in HR+, HER2– metastatic breast cancer

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Forsythe A

2018-05-01

Full Text Available Anna Forsythe,1 David Chandiwana,2 Janina Barth,3 Marroon Thabane,4 Johan Baeck,2 Gabriel Tremblay1 1Purple Squirrel Economics, New York, NY, 2Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA; 3Novartis Pharma GmbH, Nuremberg, Germany; 4Novartis Pharmaceuticals Incorporated, Dorval, QC, Canada Background: Several recent randomized controlled trials (RCTs in hormone receptor-positive (HR+, human epidermal growth factor receptor 2-negative (HER2– metastatic breast cancer (MBC have demonstrated significant improvements in progression-free survival (PFS; however, few have reported improvement in overall survival (OS. The surrogacy of PFS or time to progression (TTP for OS has not been formally investigated in HR+, HER2– MBC.Methods: A systematic literature review of RCTs in HR+, HER2– MBC was conducted to identify studies that reported both median PFS/TTP and OS. The correlation between PFS/TTP and OS was evaluated using Pearson’s product–moment correlation and Spearman’s rank correlation. Subgroup analyses were performed to explore possible reasons for heterogeneity. Errors-in-variables weighted least squares regression (LSR was used to model incremental OS months as a function of incremental PFS/TTP months. An exploratory analysis investigated the impact of three covariates (chemotherapy vs hormonal/targeted therapy, PFS vs TTP, and first-line therapy vs second-line therapy or greater on OS prediction. The lower 95% prediction band was used to determine the minimum incremental PFS/TTP months required to predict OS benefit (surrogate threshold effect [STE].Results: Forty studies were identified. There was a statistically significant correlation between median PFS/TTP and OS (Pearson =0.741, P=0.000; Spearman =0.650, P=0.000. These results proved consistent for chemotherapy and hormonal/targeted therapy. Univariate LSR analysis yielded an R2 of 0.354 with 1 incremental PFS/TTP month corresponding to 1.13 incremental OS months

Effect of antibiotic decontamination of the GI tract on survival time after neutron and gamma irradiation

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Geraci, J.P.; Jackson, K.L.; Mariano, M.S.

1984-01-01

Antibiotic decontaminated and conventional rats were whole-body irradiated with 8 MeV neutrons (1.5 to 13 Gy) or 137 Cs gamma radiation (9 to 20 Gy). The animals were checked for survival at four hour intervals from the second to the seventh day postirradiation and at eight hour intervals on other days. Decontamination of the GI tract increased median survival time 1 to 5 days in this range of dose dependency, whereas the effect of decontamination was negligible for doses that produced mostly intestinal death. These results suggest that sepsis and endotoxin produced by bacteria from the intestinal tract play little role in acute intestinal radiation death

Effects of larvicidal and larval nutritional stresses on Anopheles gambiae development, survival and competence for Plasmodium falciparum.

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Vantaux, Amélie; Ouattarra, Issiaka; Lefèvre, Thierry; Dabiré, Kounbobr Roch

2016-04-23

Many studies have shown that the environment in which larvae develop can influence adult characteristics with consequences for the transmission of pathogens. We investigated how two environmental stresses (larviciding and nutritional stress) interact to affect Anopheles gambiae (previously An. gambiae S molecular form) life history traits and its susceptibility for field isolates of its natural malaria agent Plasmodium falciparum. Larvae were reared in the presence or not of a sub-lethal concentration of larvicide and under a high and low food regimen. Development time, individual size, adult survival and competence for P. falciparum were assessed. Individuals under low food regimen took more time to develop, had a lower development success and were smaller while there was no main effect of larvicide exposure on these traits. However, larvicide exposure impacted individual size in interaction with nutritional stress. Female survival was affected by the interaction between gametocytemia, parasite exposure and larval diet, as well as the interaction between gametocytemia, parasite exposure and larvicidal stress, and the interaction between gametocytemia, larvicidal exposure and larval diet. Among the 951 females dissected 7 days post-infection, 559 (58.78%) harboured parasites. Parasite prevalence was significantly affected by the interaction between larvicidal stress and larval diet. Indeed, females under low food regimen had a higher prevalence than females under high food regimen and this difference was greater under larvicidal stress. The two stresses did not impact parasite intensity. We found that larval nutritional and larvicidal stresses affect mosquito life history traits in complex ways, which could greatly affect P. falciparum transmission. Further studies combining field-based trials on larvicide use and mosquito experimental infections would give a more accurate understanding of the effects of this vector control tool on malaria transmission.

Single nucleotide polymorphisms in the D-loop region of mitochondrial DNA is associated with the kidney survival time in chronic kidney disease patients.

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Xu, Jinsheng; Guo, Zhanjun; Bai, Yaling; Zhang, Junxia; Cui, Liwen; Zhang, Huiran; Zhang, Shenglei; Ai, Xiaolu

2015-02-01

The mitochondrial displacement loop (D-loop) is known to accumulate mutations and SNPs at a higher frequency than other regions of mitochondrial DNA (mtDNA). We had identified chronic kidney disease (CKD) risk-associated SNPs in the D-loop of CKD patients previously. In this study, we investigated the association of SNPs in the D-loop of mtDNA with the kidney survival of CKD. The D-loop region of mtDNA was sequenced for 119 CKD patients from the inpatient of the Fourth Hospital of Hebei Medical University. The Kaplan-Meier method was used to identify disease outcome-associated SNPs in the D-loop of CKD patients. The Cox proportional hazards model was used to identify risk factors for the kidney survival of CKD. In the present study, we identified 20 SNPs with a frequency higher than 5% and assessed the relationship of these SNPs with kidney survival time in CKD patients, a SNP of 146 was identified by log-rank test for statistically significant prediction of the kidney survival time. In an overall multivariate analysis, allele 146 was identified as an independent predictor of kidney survival time in CKD patients. The survival time of kidney in the CKD patients with 146C was significantly shorter than that of kidney in CKD patients with 146T (relative risk, 2.336; 95% CI, 1.319-3.923; p = 0.001). SNPs in the D-loop can predict the kidney survival of CKD patients. Analysis of genetic polymorphisms in the mitochondrial D-loop can help to identify CKD patient subgroup at high risk of a poor disease outcome.

Understanding survival analysis: Kaplan-Meier estimate.

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Goel, Manish Kumar; Khanna, Pardeep; Kishore, Jugal

2010-10-01

Kaplan-Meier estimate is one of the best options to be used to measure the fraction of subjects living for a certain amount of time after treatment. In clinical trials or community trials, the effect of an intervention is assessed by measuring the number of subjects survived or saved after that intervention over a period of time. The time starting from a defined point to the occurrence of a given event, for example death is called as survival time and the analysis of group data as survival analysis. This can be affected by subjects under study that are uncooperative and refused to be remained in the study or when some of the subjects may not experience the event or death before the end of the study, although they would have experienced or died if observation continued, or we lose touch with them midway in the study. We label these situations as censored observations. The Kaplan-Meier estimate is the simplest way of computing the survival over time in spite of all these difficulties associated with subjects or situations. The survival curve can be created assuming various situations. It involves computing of probabilities of occurrence of event at a certain point of time and multiplying these successive probabilities by any earlier computed probabilities to get the final estimate. This can be calculated for two groups of subjects and also their statistical difference in the survivals. This can be used in Ayurveda research when they are comparing two drugs and looking for survival of subjects.

Multiple imputation for estimating the risk of developing dementia and its impact on survival.

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Yu, Binbing; Saczynski, Jane S; Launer, Lenore

2010-10-01

Dementia, Alzheimer's disease in particular, is one of the major causes of disability and decreased quality of life among the elderly and a leading obstacle to successful aging. Given the profound impact on public health, much research has focused on the age-specific risk of developing dementia and the impact on survival. Early work has discussed various methods of estimating age-specific incidence of dementia, among which the illness-death model is popular for modeling disease progression. In this article we use multiple imputation to fit multi-state models for survival data with interval censoring and left truncation. This approach allows semi-Markov models in which survival after dementia depends on onset age. Such models can be used to estimate the cumulative risk of developing dementia in the presence of the competing risk of dementia-free death. Simulations are carried out to examine the performance of the proposed method. Data from the Honolulu Asia Aging Study are analyzed to estimate the age-specific and cumulative risks of dementia and to examine the effect of major risk factors on dementia onset and death.

The effect of timing and graft dysfunction on survival and cardiac allograft vasculopathy in antibody-mediated rejection.

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Clerkin, Kevin J; Restaino, Susan W; Zorn, Emmanuel; Vasilescu, Elena R; Marboe, Charles C; Mancini, Donna M

2016-09-01

Antibody-mediated rejection (AMR) has been associated with increased death and cardiac allograft vasculopathy (CAV). Early studies suggested that late AMR was rarely associated with graft dysfunction, whereas recent reports have demonstrated an association with increased mortality. We investigated the timing of AMR and its association with graft dysfunction, death, and CAV. This retrospective cohort study identified all adult orthotopic heart transplant (OHT) recipients (N = 689) at Columbia University Medical Center from 2004 to 2013. There were 68 primary cases of AMR, which were stratified by early ( 1 year post-OHT) AMR. Kaplan-Meier survival analysis and modeling was performed with multivariable logistic regression and Cox proportional hazards regression. From January 1, 2004, through October 1, 2015, early AMR (median 23 days post-OHT) occurred in 43 patients and late AMR (median 1,084 days post-OHT) occurred in 25. Graft dysfunction was less common with early compared with late AMR (25.6% vs 56%, p = 0.01). Patients with late AMR had decreased post-AMR survival compared with early AMR (1 year: 80% vs 93%, 5 years: 51% vs 73%, p < 0.05). When stratified by graft dysfunction, only those with late AMR and graft dysfunction had worse survival (30 days: 79%, 1 year: 64%, 5 years: 36%; p < 0.006). The association remained irrespective of age, sex, donor-specific antibodies, left ventricular assist device use, reason for OHT, and recovery of graft function. Similarly, those with late AMR and graft dysfunction had accelerated development of de novo CAV (50% at 1 year; hazard ratio, 5.42; p = 0.009), whereas all other groups were all similar to the general transplant population. Late AMR is frequently associated with graft dysfunction. When graft dysfunction is present in late AMR, there is an early and sustained increased risk of death and rapid development of de novo CAV despite aggressive treatment. Copyright © 2016 International Society for Heart and Lung

A protocol for storage and long-distance shipment of Mediterranean fruit fly (Diptera: Tephritidae) eggs. 1. Effect of temperature, embryo age , and storage time on survival and quality

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Caceres, C.; Wornoayporn, V.; Islam, S.M.; Ahmad, S.; Ramirez, E.

2007-01-01

The operational use of Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann), genetic sexing strains in Sterile Insect Technique applications can be maximized by developing methods for effective shipment of eggs. This would enable a central production facility to maintain the relevant mother stocks and large colonies to supply eggs to satellite centers that would mass produce only males for irradiation and release. In order to achieve this, the survival of medfly embryos of different ages was assessed after storage at 5, 10, 15, 20, and 25 deg. C in water for different periods of time. Survival was affected by all 3 variables, i.e., embryo age, water temperature, and length of storage. Storage of embryos at any temperature for 120 h resulted in almost no survival. Controlling the age of the embryo at the time of the temperature treatment is crucial for the success of this procedure. Embryos collected between 0 to 12 h after oviposition and pre-incubated at 25 deg. C for 12 h provide a suitable 72 h window for shipment when maintained between 10 to 15 deg. C. Under these conditions, no significant reductions in survival during all the developmental stages were observed. (author) [es

Survival and Neurodevelopmental Outcomes among Periviable Infants.

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Younge, Noelle; Goldstein, Ricki F; Bann, Carla M; Hintz, Susan R; Patel, Ravi M; Smith, P Brian; Bell, Edward F; Rysavy, Matthew A; Duncan, Andrea F; Vohr, Betty R; Das, Abhik; Goldberg, Ronald N; Higgins, Rosemary D; Cotten, C Michael

2017-02-16

Data reported during the past 5 years indicate that rates of survival have increased among infants born at the borderline of viability, but less is known about how increased rates of survival among these infants relate to early childhood neurodevelopmental outcomes. We compared survival and neurodevelopmental outcomes among infants born at 22 to 24 weeks of gestation, as assessed at 18 to 22 months of corrected age, across three consecutive birth-year epochs (2000-2003 [epoch 1], 2004-2007 [epoch 2], and 2008-2011 [epoch 3]). The infants were born at 11 centers that participated in the National Institute of Child Health and Human Development Neonatal Research Network. The primary outcome measure was a three-level outcome - survival without neurodevelopmental impairment, survival with neurodevelopmental impairment, or death. After accounting for differences in infant characteristics, including birth center, we used multinomial generalized logit models to compare the relative risk of survival without neurodevelopmental impairment, survival with neurodevelopmental impairment, and death. Data on the primary outcome were available for 4274 of 4458 infants (96%) born at the 11 centers. The percentage of infants who survived increased from 30% (424 of 1391 infants) in epoch 1 to 36% (487 of 1348 infants) in epoch 3 (Pneurodevelopmental impairment increased from 16% (217 of 1391) in epoch 1 to 20% (276 of 1348) in epoch 3 (P=0.001), whereas the percentage of infants who survived with neurodevelopmental impairment did not change significantly (15% [207 of 1391] in epoch 1 and 16% [211 of 1348] in epoch 3, P=0.29). After adjustment for changes in the baseline characteristics of the infants over time, both the rate of survival with neurodevelopmental impairment (as compared with death) and the rate of survival without neurodevelopmental impairment (as compared with death) increased over time (adjusted relative risks, 1.27 [95% confidence interval {CI}, 1.01 to 1.59] and 1

[Effects of relic microorganism B. sp. on development, gaseous exchange, spontaneous motor activity, stress resistance and survival of Drosophila melanogaster].

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Brushkov, A V; Bezrukov, V V; Griva, G I; Muradian, Kh K

2011-01-01

The effect of relic microorganism B. sp., living in severe environment of Siberian permafrost during thousands and millions of years, on development and stress resistance of Drosophila melanogaster has been studied. In manipulating with such objects with practically "eternal life span", molecular carriers of the unprecedented longevity potential and possibilities of their transmission to other biological objects should primarily be addressed. Here we discuss for the first time the influence of B. sp. application on development, survival, stress resistance and the gross physiological predictors of aging rate in D. melanogaster. To establish optimal and toxic doses, wide range of B. sp. concentrations were tested (1-500 million cells of B. sp. per 1 ml of the flies feeding medium). Surprisingly, no toxic effects of B. sp. could be registered even on such a "sensitive" model as the developing larvae. In fact, the rate of development, survival and body mass gradually increased with elevation of B. sp. concentration. The gain of higher body mass within shorter periods of development could indicate enhanced anabolic and/ or declined catabolic effects of B. sp. Higher motor activity and gaseous exchange rates were observed in imagoes developed on the mediums with B. sp. application. Survival of these flies at the heat shock (30 min at 38 degrees C) and ultraviolet irradiation (60 min, 50W UV lamp) was increased, indicating elevated stress resistance, apparently due to stimulation of DNA-repair and chaperone-mediated protection of macromolecules. Further research is clearly warranted to identify more efficient anti-stress and antiaging preparations and schemes of B. sp. application on models of laboratory mammals and human cell cultures.

Feed Conversion, Survival and Development, and Composition of Four Insect Species on Diets Composed of Food By-Products.

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Dennis G A B Oonincx

Full Text Available A large part of the environmental impact of animal production systems is due to the production of feed. Insects are suggested to efficiently convert feed to body mass and might therefore form a more sustainable food and/or feed source. Four diets were composed from by-products of food manufacturing and formulated such as to vary in protein and fat content. These were offered to newly hatched Argentinean cockroaches, black soldier flies, yellow mealworms, and house crickets. The first two species are potentially interesting as a feed ingredient, while the latter two are considered edible for humans. Feed conversion efficiency, survival, development time, as well as chemical composition (nitrogen, phosphorus, and fatty acids, were determined. The Argentinean cockroaches and the black soldier flies converted feed more efficiently than yellow mealworms, and house crickets. The first two were also more efficient than conventional production animals. On three of the four diets yellow mealworms and house crickets had a feed conversion efficiency similar to pigs. Furthermore, on the most suitable diet, they converted their feed as efficiently as poultry, when corrected for edible portion. All four species had a higher nitrogen-efficiency than conventional production animals, when corrected for edible portion. Offering carrots to yellow mealworms increased dry matter- and nitrogen-efficiency and decreased development time. Diet affected survival in all species but black soldier flies, and development time was strongly influenced in all four species. The chemical composition of Argentinean cockroaches was highly variable between diets, for black soldier flies it remained similar. The investigated species can be considered efficient production animals when suitable diets are provided. Hence, they could form a sustainable alternative to conventional production animals as a source of feed or food.

Feed Conversion, Survival and Development, and Composition of Four Insect Species on Diets Composed of Food By-Products

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Oonincx, Dennis G. A. B.; van Broekhoven, Sarah; van Huis, Arnold; van Loon, Joop J. A.

2015-01-01

A large part of the environmental impact of animal production systems is due to the production of feed. Insects are suggested to efficiently convert feed to body mass and might therefore form a more sustainable food and/or feed source. Four diets were composed from by-products of food manufacturing and formulated such as to vary in protein and fat content. These were offered to newly hatched Argentinean cockroaches, black soldier flies, yellow mealworms, and house crickets. The first two species are potentially interesting as a feed ingredient, while the latter two are considered edible for humans. Feed conversion efficiency, survival, development time, as well as chemical composition (nitrogen, phosphorus, and fatty acids), were determined. The Argentinean cockroaches and the black soldier flies converted feed more efficiently than yellow mealworms, and house crickets. The first two were also more efficient than conventional production animals. On three of the four diets yellow mealworms and house crickets had a feed conversion efficiency similar to pigs. Furthermore, on the most suitable diet, they converted their feed as efficiently as poultry, when corrected for edible portion. All four species had a higher nitrogen-efficiency than conventional production animals, when corrected for edible portion. Offering carrots to yellow mealworms increased dry matter- and nitrogen-efficiency and decreased development time. Diet affected survival in all species but black soldier flies, and development time was strongly influenced in all four species. The chemical composition of Argentinean cockroaches was highly variable between diets, for black soldier flies it remained similar. The investigated species can be considered efficient production animals when suitable diets are provided. Hence, they could form a sustainable alternative to conventional production animals as a source of feed or food. PMID:26699129

Feed Conversion, Survival and Development, and Composition of Four Insect Species on Diets Composed of Food By-Products.

Science.gov (United States)

Oonincx, Dennis G A B; van Broekhoven, Sarah; van Huis, Arnold; van Loon, Joop J A

2015-01-01

A large part of the environmental impact of animal production systems is due to the production of feed. Insects are suggested to efficiently convert feed to body mass and might therefore form a more sustainable food and/or feed source. Four diets were composed from by-products of food manufacturing and formulated such as to vary in protein and fat content. These were offered to newly hatched Argentinean cockroaches, black soldier flies, yellow mealworms, and house crickets. The first two species are potentially interesting as a feed ingredient, while the latter two are considered edible for humans. Feed conversion efficiency, survival, development time, as well as chemical composition (nitrogen, phosphorus, and fatty acids), were determined. The Argentinean cockroaches and the black soldier flies converted feed more efficiently than yellow mealworms, and house crickets. The first two were also more efficient than conventional production animals. On three of the four diets yellow mealworms and house crickets had a feed conversion efficiency similar to pigs. Furthermore, on the most suitable diet, they converted their feed as efficiently as poultry, when corrected for edible portion. All four species had a higher nitrogen-efficiency than conventional production animals, when corrected for edible portion. Offering carrots to yellow mealworms increased dry matter- and nitrogen-efficiency and decreased development time. Diet affected survival in all species but black soldier flies, and development time was strongly influenced in all four species. The chemical composition of Argentinean cockroaches was highly variable between diets, for black soldier flies it remained similar. The investigated species can be considered efficient production animals when suitable diets are provided. Hence, they could form a sustainable alternative to conventional production animals as a source of feed or food.

The comparison of proportional hazards and accelerated failure time models in analyzing the first birth interval survival data

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Faruk, Alfensi

2018-03-01

Survival analysis is a branch of statistics, which is focussed on the analysis of time- to-event data. In multivariate survival analysis, the proportional hazards (PH) is the most popular model in order to analyze the effects of several covariates on the survival time. However, the assumption of constant hazards in PH model is not always satisfied by the data. The violation of the PH assumption leads to the misinterpretation of the estimation results and decreasing the power of the related statistical tests. On the other hand, the accelerated failure time (AFT) models do not assume the constant hazards in the survival data as in PH model. The AFT models, moreover, can be used as the alternative to PH model if the constant hazards assumption is violated. The objective of this research was to compare the performance of PH model and the AFT models in analyzing the significant factors affecting the first birth interval (FBI) data in Indonesia. In this work, the discussion was limited to three AFT models which were based on Weibull, exponential, and log-normal distribution. The analysis by using graphical approach and a statistical test showed that the non-proportional hazards exist in the FBI data set. Based on the Akaike information criterion (AIC), the log-normal AFT model was the most appropriate model among the other considered models. Results of the best fitted model (log-normal AFT model) showed that the covariates such as women’s educational level, husband’s educational level, contraceptive knowledge, access to mass media, wealth index, and employment status were among factors affecting the FBI in Indonesia.

[The survival and development conditions of community-based organizations for HIV/AIDS prevention and control among men who have sex with men in three Chinese cities].

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Fu, Xiaojing; Shan, Duo; Qi, Jinlei; Ouyang, Lin; Wang, Hui; Fu, Jie; Sun, Jiangping

2015-06-01

To investigate the survival and development conditions of community-based organizations (CBOs) for HIV/AIDS prevention and control among men who have sex with men (MSM) in Chinese cities including Shanghai, Hangzhou, Chongqing. This study employed both qualitative (focus groups) and quantitative (questionnaire survey) methods to obtain information from 15 MSM CBOs in three Chinese cities. The mean work time of the 15 CBOs for HIV/AIDS prevention and control among MSM was 6.7 years (2.1-11.3 years), and the majority of their funds was from international cooperation projects (80 447 000 RMB, 73.0%) from 2006 to 2013. The survival cost of MSM CBOs apart from expenditure of activities was 2 240-435 360 RMB per year. As it was shown in the graph, the survival and development of MSM CBOs was closely related to the development of international cooperation projects. There was a few small size MSM CBOs taking part in the prevention and control of HIV/AIDS and their work content was limited before 2006. From 2006 to 2008, some international cooperation projects were launched in China, such as the China Global Fund AIDS project and the China-Gates Foundation HIV Prevention Cooperation program. As a result, the number of MSM CBOs was increased sharply, and both the scale and 2012, the performance of these programs further promote the establishment of new MSM CBOs and the development of all MSM CBOs with regard to the work places, full-time staffs, work contents, work patterns and the specific targeted population. After 2012, most international cooperation programs were completed and the local department of disease prevention and control continued to cooperate with MSM CBOs. However, the degree of support funds from the local department was different among different regions. Where the funds were below the half of program funds, the development of MSM CBOs ceased and work slowed down. Besides, there were still some constraints for the survival and development of MSM CBOs, such

Time-of-Day Dependent Neuronal Injury After Ischemic Stroke: Implication of Circadian Clock Transcriptional Factor Bmal1 and Survival Kinase AKT.

Science.gov (United States)

Beker, Mustafa Caglar; Caglayan, Berrak; Yalcin, Esra; Caglayan, Ahmet Burak; Turkseven, Seyma; Gurel, Busra; Kelestemur, Taha; Sertel, Elif; Sahin, Zafer; Kutlu, Selim; Kilic, Ulkan; Baykal, Ahmet Tarik; Kilic, Ertugrul

2018-03-01

Occurrence of stroke cases displays a time-of-day variation in human. However, the mechanism linking circadian rhythm to the internal response mechanisms against pathophysiological events after ischemic stroke remained largely unknown. To this end, temporal changes in the susceptibility to ischemia/reperfusion (I/R) injury were investigated in mice in which the ischemic stroke induced at four different Zeitgeber time points with 6-h intervals (ZT0, ZT6, ZT12, and ZT18). Besides infarct volume and brain swelling, neuronal survival, apoptosis, ischemia, and circadian rhythm related proteins were examined using immunohistochemistry, Western blot, planar surface immune assay, and liquid chromatography-mass spectrometry tools. Here, we present evidence that midnight (ZT18; 24:00) I/R injury in mice resulted in significantly improved infarct volume, brain swelling, neurological deficit score, neuronal survival, and decreased apoptotic cell death compared with ischemia induced at other time points, which were associated with increased expressions of circadian proteins Bmal1, PerI, and Clock proteins and survival kinases AKT and Erk-1/2. Moreover, ribosomal protein S6, mTOR, and Bad were also significantly increased, while the levels of PRAS40, negative regulator of AKT and mTOR, and phosphorylated p53 were decreased at this time point compared to ZT0 (06:00). Furthermore, detailed proteomic analysis revealed significantly decreased CSKP, HBB-1/2, and HBA levels, while increased GNAZ, NEGR1, IMPCT, and PDE1B at midnight as compared with early morning. Our results indicate that nighttime I/R injury results in less severe neuronal damage, with increased neuronal survival, increased levels of survival kinases and circadian clock proteins, and also alters the circadian-related proteins.

Determinants of IPO survival on the Johannesburg securities exchange

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Brownhilder Ngek Neneh

2014-10-01

Full Text Available The purpose of this paper was to establish the determinants of IPO survival on the Johannesburg Securities Exchange (JSE. Using the Kaplan-Meier test, this study established that firms less than five years prior to listing on the JSE have a significant smaller mean survival time; firms with a gross proceed less than the median have a significant shorter mean survival time; overpriced IPOs have a significant higher survival time; IPOs listed during the hot market period on the JSE have a significant smaller mean survival time and IPOs with return on asset, operating profit margin, and return on equity less than or equal to zero have a low mean survival time. Also, being in the internet industry significantly shortens the mean survival time of an IPO. Moreover, based on the Cox Proportional Hazard model, it was established that the determinants of IPO survivability on the JSE are the firms’ age, size, market period, return on equity and operating profit margin are. These findings provide investors and companies in the JSE with empirical evidence of the determinants of IPO survivability of the JSE. As such, investors are advised to consider these factors when selecting their portfolios

Effects of fine sediment, hyporheic flow, and spawning site characteristics on survival and development of bull trout embryos

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Bowerman, Tracy; Neilson, Bethany; Budy, Phaedra

2014-01-01

Successful spawning is imperative for the persistence of salmonid populations, but relatively little research has been conducted to evaluate factors affecting early life-stage survival for bull trout (Salvelinus confluentus), a threatened char. We conducted a field experiment to assess the relationship between site-specific environmental factors and bull trout embryo survival and fry emergence timing. Survival from egg to hatch was negatively related to percent fine sediment (construction and selection of spawning sites with strong downwelling appear to enhance hyporheic flow rates and bull trout egg survival, but early life-stage success may ultimately be limited by intrusion of fine sediment into the incubation environment.

Compromised development and survival in amphibians in reclaimed wetlands' water containing oil sands process-affected material

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Smits, J.; Schock, D.

2010-01-01

When closing a mine, operators must comply with government regulations to ensure that the sites are ecologically sustainable to support endemic flora and fauna. Creating wetlands in order to age and detoxify oil sands process-affected materials (OSPM) is a common reclamation strategy. In this study, amphibians indigenous to the boreal forest ecosystem were examined to determine if they can complete their lifecycle in water from reclaimed wetlands. Wood frog (Lithobates sylvaticus) eggs were collected from a natural pond 60 km south of an oil sand mining site. Tadpoles were raised in 1 of 6 water treatments refreshed every two days. The 2 reference water treatments included aged tap water and water from natural wetlands. The remaining 4 water treatments were from research wetlands on Syncrude and Suncor lease sites. Of the 120 tadpoles raised per water treatment, there was no significant difference in growth, development, or survival rates between the aged tap water and reference wetland water, but the fastest growth, development, and highest survival rates occurred in the two reference groups. There was a pronounced difference among the 4 treatment groups from Suncor and Syncrude reclamation sites. Survival was high in 3 of the water treatments from Syncrude and Suncor sites, but development rates were considerably reduced. Tadpoles that do not metamorphose before winter do not survive. It was therefore concluded that delayed development in tadpoles poses a serious risk to population stability in OSPM-containing wetlands.

Developing an analytical tool for evaluating EMS system design changes and their impact on cardiac arrest outcomes: combining geographic information systems with register data on survival rates

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Sund Björn

2013-02-01

Full Text Available Abstract Background Out-of-hospital cardiac arrest (OHCA is a frequent and acute medical condition that requires immediate care. We estimate survival rates from OHCA in the area of Stockholm, through developing an analytical tool for evaluating Emergency Medical Services (EMS system design changes. The study also is an attempt to validate the proposed model used to generate the outcome measures for the study. Methods and results This was done by combining a geographic information systems (GIS simulation of driving times with register data on survival rates. The emergency resources comprised ambulance alone and ambulance plus fire services. The simulation model predicted a baseline survival rate of 3.9 per cent, and reducing the ambulance response time by one minute increased survival to 4.6 per cent. Adding the fire services as first responders (dual dispatch increased survival to 6.2 per cent from the baseline level. The model predictions were validated using empirical data. Conclusion We have presented an analytical tool that easily can be generalized to other regions or countries. The model can be used to predict outcomes of cardiac arrest prior to investment in EMS design changes that affect the alarm process, e.g. (1 static changes such as trimming the emergency call handling time or (2 dynamic changes such as location of emergency resources or which resources should carry a defibrillator.

Covariate analysis of bivariate survival data

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Bennett, L.E.

1992-01-01

The methods developed are used to analyze the effects of covariates on bivariate survival data when censoring and ties are present. The proposed method provides models for bivariate survival data that include differential covariate effects and censored observations. The proposed models are based on an extension of the univariate Buckley-James estimators which replace censored data points by their expected values, conditional on the censoring time and the covariates. For the bivariate situation, it is necessary to determine the expectation of the failure times for one component conditional on the failure or censoring time of the other component. Two different methods have been developed to estimate these expectations. In the semiparametric approach these expectations are determined from a modification of Burke's estimate of the bivariate empirical survival function. In the parametric approach censored data points are also replaced by their conditional expected values where the expected values are determined from a specified parametric distribution. The model estimation will be based on the revised data set, comprised of uncensored components and expected values for the censored components. The variance-covariance matrix for the estimated covariate parameters has also been derived for both the semiparametric and parametric methods. Data from the Demographic and Health Survey was analyzed by these methods. The two outcome variables are post-partum amenorrhea and breastfeeding; education and parity were used as the covariates. Both the covariate parameter estimates and the variance-covariance estimates for the semiparametric and parametric models will be compared. In addition, a multivariate test statistic was used in the semiparametric model to examine contrasts. The significance of the statistic was determined from a bootstrap distribution of the test statistic.

Parent-child communication and marijuana initiation: evidence using discrete-time survival analysis.

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Nonnemaker, James M; Silber-Ashley, Olivia; Farrelly, Matthew C; Dench, Daniel

2012-12-01

This study supplements existing literature on the relationship between parent-child communication and adolescent drug use by exploring whether parental and/or adolescent recall of specific drug-related conversations differentially impact youth's likelihood of initiating marijuana use. Using discrete-time survival analysis, we estimated the hazard of marijuana initiation using a logit model to obtain an estimate of the relative risk of initiation. Our results suggest that parent-child communication about drug use is either not protective (no effect) or - in the case of youth reports of communication - potentially harmful (leading to increased likelihood of marijuana initiation). Copyright © 2012 Elsevier Ltd. All rights reserved.

Development of a Summarized Health Index (SHI for use in predicting survival in sea turtles.

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Tsung-Hsien Li

Full Text Available Veterinary care plays an influential role in sea turtle rehabilitation, especially in endangered species. Physiological characteristics, hematological and plasma biochemistry profiles, are useful references for clinical management in animals, especially when animals are during the convalescence period. In this study, these factors associated with sea turtle surviving were analyzed. The blood samples were collected when sea turtles remained alive, and then animals were followed up for surviving status. The results indicated that significantly negative correlation was found between buoyancy disorders (BD and sea turtle surviving (p < 0.05. Furthermore, non-surviving sea turtles had significantly higher levels of aspartate aminotranspherase (AST, creatinine kinase (CK, creatinine and uric acid (UA than surviving sea turtles (all p < 0.05. After further analysis by multiple logistic regression model, only factors of BD, creatinine and UA were included in the equation for calculating summarized health index (SHI for each individual. Through evaluation by receiver operating characteristic (ROC curve, the result indicated that the area under curve was 0.920 ± 0.037, and a cut-off SHI value of 2.5244 showed 80.0% sensitivity and 86.7% specificity in predicting survival. Therefore, the developed SHI could be a useful index to evaluate health status of sea turtles and to improve veterinary care at rehabilitation facilities.

Effect of time interval between capecitabine intake and radiotherapy on local recurrence-free survival in preoperative chemoradiation for locally advanced rectal cancer

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Kim, Yeon Joo; Kim, Jong Hoon; Yu, Chang Sik; Kim, Tae Won; Jang, Se Jin; Choi, Eun Kyung; Kim, Jin Cheon [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Choi, Won Sik [University of Ulsan College of Medicine, Gangneung (Korea, Republic of)

2017-06-15

The concentration of capecitabine peaks at 1–2 hours after administration. We therefore assumed that proper timing of capecitabine administration and radiotherapy would maximize radiosensitization and influence survival among patients with locally advanced rectal cancer. We retrospectively reviewed 223 patients with locally advanced rectal cancer who underwent preoperative chemoradiation, followed by surgery from January 2002 to May 2006. All patients underwent pelvic radiotherapy (50 Gy/25 fractions) and received capecitabine twice daily at 12-hour intervals (1,650 mg/m2/day). Patients were divided into two groups according to the time interval between capecitabine intake and radiotherapy. Patients who took capecitabine 1 hour before radiotherapy were classified as Group A (n = 109); all others were classified as Group B (n = 114). The median follow-up period was 72 months (range, 7 to 149 months). Although Group A had a significantly higher rate of good responses (44% vs. 25%; p = 0.005), the 5-year local recurrence-free survival rates of 93% in Group A and 97% in Group B did not differ significantly (p = 0.519). The 5-year disease-free survival and overall survival rates were also comparable between the groups. Despite the better pathological response in Group A, the time interval between capecitabine and radiotherapy administration did not have a significant effect on survivals. Further evaluations are needed to clarify the interaction of these treatment modalities.

Timing of chemotherapy and survival in patients with resectable gastric adenocarcinoma

Science.gov (United States)

Arrington, Amanda K; Nelson, Rebecca; Patel, Supriya S; Luu, Carrie; Ko, Michelle; Garcia-Aguilar, Julio; Kim, Joseph

2013-01-01

AIM: To evaluate the timing of chemotherapy in gastric cancer by comparing survival outcomes in treatment groups. METHODS: Patients with surgically resected gastric adenocarcinoma from 1988 to 2006 were identified from the Los Angeles County Cancer Surveillance Program. To evaluate the population most likely to receive and/or benefit from adjunct chemotherapy, inclusion criteria consisted of Stage II or III gastric cancer patients > 18 years of age who underwent curative-intent surgical resection. Patients were categorized into three groups according to the receipt of chemotherapy: (1) no chemotherapy; (2) preoperative chemotherapy; or (3) postoperative chemotherapy. Clinical and pathologic characteristics were compared across the different treatment arms. RESULTS: Of 1518 patients with surgically resected gastric cancer, 327 (21.5%) received perioperative chemotherapy. The majority of these 327 patients were male (68%) with a mean age of 61.5 years; and they were significantly younger than non-chemotherapy patients (mean age, 70.7; P advanced gastric cancer. CONCLUSION: This study supports the implementation of a randomized trial comparing the timing of perioperative therapy in patients with locally advanced gastric cancer. PMID:24392183

Topoisomerase IIbeta is required for proper retinal development and survival of postmitotic cells

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Ying Li

2014-01-01

Topoisomerase IIbeta (Top2b is an enzyme that modulates DNA supercoiling by catalyzing the passage of DNA duplexes through one another. It is ubiquitously expressed in postmitotic cells and known to function during the development of neuromuscular junctions in the diaphragm and the proper formation of laminar structure in the cerebral cortex. However, due to the perinatal death phenotype of the traditional constitutive and brain-specific Top2b knockout mice, the precise in vivo function of Top2b, especially during postnatal neural development, remains to be determined. Using both the constitutive and retina-specific knockout mouse models, we showed that Top2b deficiency resulted in delayed neuronal differentiation, degeneration of the plexiform layers and outer segment of photoreceptors, as well as dramatic reduction in cell number in the retina. Genome-wide transcriptome analysis by RNA sequencing revealed that genes involved in neuronal survival and neural system development were preferentially affected in Top2b-deficient retinas. Collectively, our findings have indicated an important function of Top2b in proper development and the maintenance/survival of postmitotic neurons in the retina.

Nutrition management methods effective in increasing weight, survival time and functional status in ALS patients: a systematic review.

Science.gov (United States)

Kellogg, Jaylin; Bottman, Lindsey; Arra, Erin J; Selkirk, Stephen M; Kozlowski, Frances

2018-02-01

Poor prognosis and decreased survival time correlate with the nutritional status of patients with amyotrophic lateral sclerosis (ALS). Various studies were reviewed which assessed weight, body mass index (BMI), survival time and ALS functional rating scale revised (ALSFRS-R) in order to determine the best nutrition management methods for this patient population. A systematic review was conducted using CINAHL, Medline, and PubMed, and various search terms in order to determine the most recent clinical trials and observational studies that have been conducted concerning nutrition and ALS. Four articles met criteria to be included in the review. Data were extracted from these articles and were inputted into the Data Extraction Tool (DET) provided by the Academy of Nutrition and Dietetics (AND). Results showed that nutrition supplementation does promote weight stabilisation or weight gain in individuals with ALS. Given the low risk and low cost associated with intervention, early and aggressive nutrition intervention is recommended. This systematic review shows that there is a lack of high quality evidence regarding the efficacy of any dietary interventions for promoting survival in ALS or slowing disease progression; therefore more research is necessary related to effects of nutrition interventions.

Using simulation to interpret a discrete time survival model in a complex biological system: fertility and lameness in dairy cows.

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Christopher D Hudson

Full Text Available The ever-growing volume of data routinely collected and stored in everyday life presents researchers with a number of opportunities to gain insight and make predictions. This study aimed to demonstrate the usefulness in a specific clinical context of a simulation-based technique called probabilistic sensitivity analysis (PSA in interpreting the results of a discrete time survival model based on a large dataset of routinely collected dairy herd management data. Data from 12,515 dairy cows (from 39 herds were used to construct a multilevel discrete time survival model in which the outcome was the probability of a cow becoming pregnant during a given two day period of risk, and presence or absence of a recorded lameness event during various time frames relative to the risk period amongst the potential explanatory variables. A separate simulation model was then constructed to evaluate the wider clinical implications of the model results (i.e. the potential for a herd's incidence rate of lameness to influence its overall reproductive performance using PSA. Although the discrete time survival analysis revealed some relatively large associations between lameness events and risk of pregnancy (for example, occurrence of a lameness case within 14 days of a risk period was associated with a 25% reduction in the risk of the cow becoming pregnant during that risk period, PSA revealed that, when viewed in the context of a realistic clinical situation, a herd's lameness incidence rate is highly unlikely to influence its overall reproductive performance to a meaningful extent in the vast majority of situations. Construction of a simulation model within a PSA framework proved to be a very useful additional step to aid contextualisation of the results from a discrete time survival model, especially where the research is designed to guide on-farm management decisions at population (i.e. herd rather than individual level.

Survival analysis models and applications

CERN Document Server

Liu, Xian

2012-01-01

Survival analysis concerns sequential occurrences of events governed by probabilistic laws.  Recent decades have witnessed many applications of survival analysis in various disciplines. This book introduces both classic survival models and theories along with newly developed techniques. Readers will learn how to perform analysis of survival data by following numerous empirical illustrations in SAS. Survival Analysis: Models and Applications: Presents basic techniques before leading onto some of the most advanced topics in survival analysis.Assumes only a minimal knowledge of SAS whilst enablin

Challenges in the estimation of Net SURvival: The CENSUR working survival group.

Science.gov (United States)

Giorgi, R

2016-10-01

Net survival, the survival probability that would be observed, in a hypothetical world, where the cancer of interest would be the only possible cause of death, is a key indicator in population-based cancer studies. Accounting for mortality due to other causes, it allows cross-country comparisons or trends analysis and provides a useful indicator for public health decision-making. The objective of this study was to show how the creation and formalization of a network comprising established research teams, which already had substantial and complementary experience in both cancer survival analysis and methodological development, make it possible to meet challenges and thus provide more adequate tools, to improve the quality and the comparability of cancer survival data, and to promote methodological transfers in areas of emerging interest. The Challenges in the Estimation of Net SURvival (CENSUR) working survival group is composed of international researchers highly skilled in biostatistics, methodology, and epidemiology, from different research organizations in France, the United Kingdom, Italy, Slovenia, and Canada, and involved in French (FRANCIM) and European (EUROCARE) cancer registry networks. The expected advantages are an interdisciplinary, international, synergistic network capable of addressing problems in public health, for decision-makers at different levels; tools for those in charge of net survival analyses; a common methodology that makes unbiased cross-national comparisons of cancer survival feasible; transfer of methods for net survival estimations to other specific applications (clinical research, occupational epidemiology); and dissemination of results during an international training course. The formalization of the international CENSUR working survival group was motivated by a need felt by scientists conducting population-based cancer research to discuss, develop, and monitor implementation of a common methodology to analyze net survival in order

Influence of human development and predators on nest survival of tundra birds, Arctic Coastal Plain, Alaska.

Science.gov (United States)

Liebezeit, J R; Kendall, S J; Brown, S; Johnson, C B; Martin, P; McDonald, T L; Payer, D C; Rea, C L; Streever, B; Wildman, A M; Zack, S

2009-09-01

Nest predation may influence population dynamics of birds on the Arctic Coastal Plain (ACP) of Alaska, USA. Anthropogenic development on the ACP is increasing, which may attract nest predators by providing artificial sources of food, perches, den sites, and nest sites. Enhanced populations or concentrations of human-subsidized predators may reduce nest survival for tundra-nesting birds. In this study, we tested the hypothesis that nest survival decreases in proximity to human infrastructure. We monitored 1257 nests of 13 shorebird species and 619 nests of four passerine species at seven sites on the ACP from 2002 to 2005. Study sites were chosen to represent a range of distances to infrastructure from 100 m to 80 km. We used Cox proportional hazards regression models to evaluate the effects of background (i.e., natural) factors and infrastructure on nest survival. We documented high spatial and temporal variability in nest survival, and site and year were both included in the best background model. We did not detect an effect of human infrastructure on nest survival for shorebirds as a group. In contrast, we found evidence that risk of predation for passerine nests increased within 5 km of infrastructure. This finding provides quantitative evidence of a relationship between infrastructure and nest survival for breeding passerines on the ACP. A posteriori finer-scale analyses (within oil field sites and individual species) suggested that Red and Red-necked Phalaropes combined (Phalaropus fulicarius, P. lobatus) had lower productivity closer to infrastructure and in areas with higher abundance of subsidized predators. However, we did not detect such a relationship between infrastructure and nest survival for Semipalmated and Pectoral Sandpipers (Calidris pusilla, C. melanotos), the two most abundant shorebirds. High variability in environmental conditions, nest survival, and predator numbers between sites and years may have contributed to these inconsistent results

Survival during the Breeding Season: Nest Stage, Parental Sex, and Season Advancement Affect Reed Warbler Survival.

Directory of Open Access Journals (Sweden)

Kaja Wierucka

Full Text Available Avian annual survival has received much attention, yet little is known about seasonal patterns in survival, especially of migratory passerines. In order to evaluate survival rates and timing of mortality within the breeding season of adult reed warblers (Acrocephalus scirpaceus, mark-recapture data were collected in southwest Poland, between 2006 and 2012. A total of 612 individuals (304 females and 308 males were monitored throughout the entire breeding season, and their capture-recapture histories were used to model survival rates. Males showed higher survival during the breeding season (0.985, 95% CI: 0.941-0.996 than females (0.869, 95% CI: 0.727-0.937. Survival rates of females declined with the progression of the breeding season (from May to August, while males showed constant survival during this period. We also found a clear pattern within the female (but not male nesting cycle: survival was significantly lower during the laying, incubation, and nestling periods (0.934, 95% CI: 0.898-0.958, when birds spent much time on the nest, compared to the nest building and fledgling periods (1.000, 95% CI: 1.00-1.000, when we did not record any female mortality. These data (coupled with some direct evidence, like bird corpses or blood remains found next to/on the nest may suggest that the main cause of adult mortality was on-nest predation. The calculated survival rates for both sexes during the breeding season were high compared to annual rates reported for this species, suggesting that a majority of mortality occurs at other times of the year, during migration or wintering. These results have implications for understanding survival variation within the reproductive period as well as general trends of avian mortality.

Progression-free survival: gaining on overall survival as a gold standard and accelerating drug development.

Science.gov (United States)

Lebwohl, David; Kay, Andrea; Berg, William; Baladi, Jean Francois; Zheng, Ji

2009-01-01

In clinical trials of oncology drugs, overall survival (OS) is a direct measure of clinical efficacy and is considered the gold standard primary efficacy end point. The purpose of this study was to discuss the difficulties in using OS as a primary efficacy end point in the setting of evolving cancer therapies. We suggest that progression-free survival is an appropriate efficacy end point in many types of cancer, specifically those for which OS is expected to be prolonged and for which subsequent treatments are expected to affect OS.

'Enterprise risk management' essential for survival and sustainable development of micro, small and medium enterprises

Directory of Open Access Journals (Sweden)

Agrawal Reena

2016-01-01

Full Text Available The part that Micro, Small and Medium Enterprises (MSMEs play, both in developed and developing countries, cannot be over emphasized and therefore their existence and survival is a matter of concern not only for the policy makers but also for the researchers. Large number of MSMEs die the same year that they are established. The current research was taken up to understand how MSMEs manage their risk and whether enterprise risk management is essential for survival and sustainable development of MSMEs. The objective of the research was to (1 understand the peculiar nature of the MSMEs which make them vulnerable, (2 explore the various risks confronted by MSMEs, (3 understand how the MSMEs manage their risk, (4 understand 'Enterprise Risk Management' and its components and (5 explore the relevance of 'Enterprise Risk Management' for the survival and sustainable development of MSMEs. The results show that MSMEs by virtue of their size, inadequate resources and restricted know-how generally confront wide-ranging risks. In MSMEs the management of risk is concentrated in the hands of the owner-managers and there are no systemic linkages between the planning and risk management. Therefore, this study stresses the need for integrating an effective enterprise risk management system with planning and administration within the MSMEs, to avoid fatal consequences.

Energy development and avian nest survival in Wyoming, USA: A test of a common disturbance index

Science.gov (United States)

Hethcoat, Matthew G.; Chalfoun, Anna D.

2015-01-01

Global energy demands continue to result in new and emerging sources of anthropogenic disturbance to populations and systems. Here, we assessed the influence of natural gas development on a critical component of fitness (nest survival) for Brewer’s sparrow (Spizella breweri), sagebrush sparrow (Artemisiospiza nevadensis), and sage thrasher (Oreoscoptes montanus), three species of sagebrush-obligate songbirds that are of conservation concern, and assessed the efficacy of a commonly used index of oil and gas development intensity (well density) for estimating habitat transformation and predicting species’ responses. During 2008–2009 and 2011–2012 we monitored 926 nests within two natural gas fields in western Wyoming, USA. We calculated landscape metrics (habitat loss, amount of edge, patch shape complexity, and mean patch size) to identify the aspect of landscape transformation most captured by well density. Well density was most positively associated with the amount of sagebrush habitat loss within 1 square kilometer. Nest survival was relatively invariant with respect to well density for all three species. In contrast, nest survival rates of all three species generally decreased with surrounding habitat loss due to energy development. Thus, although well density and habitat loss were strongly correlated, well density resulted in overly conservative estimates of nest survival probability. Our results emphasize the importance of careful evaluation of the appropriateness of particular indices for quantifying the effects of human-induced habitat change. For managers concerned about the effects of natural gas development or similar forms of human land use to co-occurring breeding birds, we recommend minimizing the amount of associated habitat conversion.

Correlates of time to microvascular complications among diabetes ...

African Journals Online (AJOL)

Socio-demographic and clinical factors have been known to affect the time to microvascular complications and survival probabilities of diabetes mellitus patients. The objective of this study was to identify risk factors and estimate average survival times for the time to the development of microvascular complications of ...

Survival curves for irradiated cells

International Nuclear Information System (INIS)

Gibson, D.K.

1975-01-01

The subject of the lecture is the probability of survival of biological cells which have been subjected to ionising radiation. The basic mathematical theories of cell survival as a function of radiation dose are developed. A brief comparison with observed survival curves is made. (author)

Effect of Methyl Parathion on Survival and Development of Tadpoles of Indian Cricket frog Fejervarya limnocharis

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Hunasanahalli Puttaswamygowda Gurushankara

2016-04-01

Full Text Available Amphibian populations are declining due to various causes including pesticide contamination in natural habitat. We evaluated the effect of Methyl Parathion (MPT an organophosphate pesticide on survival and development of common paddy field frog Fejervarya limnocharis in a laboratory condition. Effect of 0 µg MPT/L, 500 µg MPT/L,1000 µg MPT/L, 1500 µg MPT/L, 2000 µg MPT/L and 3000 µg MPT/L was studied using static toxicity test for a duration of 28 days. MPT reduced the survival of tadpole. The mortality was increased with the increased concentration of pesticide. The development decreased with increased MPT concentrations. At higher concentrations, MPT induced slow development and tadpoles failed to metamorphose. It is assumed that slow development could affect the early larval life and amphibian population in the agroecosystem.

Gene expression profiling of canine osteosarcoma reveals genes associated with short and long survival times

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Rao Nagesha AS

2009-09-01

Full Text Available Abstract Background Gene expression profiling of spontaneous tumors in the dog offers a unique translational opportunity to identify prognostic biomarkers and signaling pathways that are common to both canine and human. Osteosarcoma (OS accounts for approximately 80% of all malignant bone tumors in the dog. Canine OS are highly comparable with their human counterpart with respect to histology, high metastatic rate and poor long-term survival. This study investigates the prognostic gene profile among thirty-two primary canine OS using canine specific cDNA microarrays representing 20,313 genes to identify genes and cellular signaling pathways associated with survival. This, the first report of its kind in dogs with OS, also demonstrates the advantages of cross-species comparison with human OS. Results The 32 tumors were classified into two prognostic groups based on survival time (ST. They were defined as short survivors (dogs with poor prognosis: surviving fewer than 6 months and long survivors (dogs with better prognosis: surviving 6 months or longer. Fifty-one transcripts were found to be differentially expressed, with common upregulation of these genes in the short survivors. The overexpressed genes in short survivors are associated with possible roles in proliferation, drug resistance or metastasis. Several deregulated pathways identified in the present study, including Wnt signaling, Integrin signaling and Chemokine/cytokine signaling are comparable to the pathway analysis conducted on human OS gene profiles, emphasizing the value of the dog as an excellent model for humans. Conclusion A molecular-based method for discrimination of outcome for short and long survivors is useful for future prognostic stratification at initial diagnosis, where genes and pathways associated with cell cycle/proliferation, drug resistance and metastasis could be potential targets for diagnosis and therapy. The similarities between human and canine OS makes the

Applied survival analysis using R

CERN Document Server

Moore, Dirk F

2016-01-01

Applied Survival Analysis Using R covers the main principles of survival analysis, gives examples of how it is applied, and teaches how to put those principles to use to analyze data using R as a vehicle. Survival data, where the primary outcome is time to a specific event, arise in many areas of biomedical research, including clinical trials, epidemiological studies, and studies of animals. Many survival methods are extensions of techniques used in linear regression and categorical data, while other aspects of this field are unique to survival data. This text employs numerous actual examples to illustrate survival curve estimation, comparison of survivals of different groups, proper accounting for censoring and truncation, model variable selection, and residual analysis. Because explaining survival analysis requires more advanced mathematics than many other statistical topics, this book is organized with basic concepts and most frequently used procedures covered in earlier chapters, with more advanced topics...

The Health Rationale for Family Planning: Timing of Births and Child Survival.

Science.gov (United States)

United Nations, New York, NY. Population Div.

Among the most influential findings from the World Fertility Survey (WFS) were those linking fertility patterns to child survival, in particular the findings concerning the high infant and child mortality for children born after a short birth interval. This study examined the relations between fertility and child survival based on more recent data…

PSO-Based Robot Path Planning for Multisurvivor Rescue in Limited Survival Time

Directory of Open Access Journals (Sweden)

N. Geng

2014-01-01

Full Text Available Since the strength of a trapped person often declines with time in urgent and dangerous circumstances, adopting a robot to rescue as many survivors as possible in limited time is of considerable significance. However, as one key issue in robot navigation, how to plan an optimal rescue path of a robot has not yet been fully solved. This paper studies robot path planning for multisurvivor rescue in limited survival time using a representative heuristic, particle swarm optimization (PSO. First, the robot path planning problem including multiple survivors is formulated as a discrete optimization one with high constraint, where the number of rescued persons is taken as the unique objective function, and the strength of a trapped person is used to constrain the feasibility of a path. Then, a new integer PSO algorithm is presented to solve the mathematical model, and several new operations, such as the update of a particle, the insertion and inversion operators, and the rapidly local search method, are incorporated into the proposed algorithm to improve its effectiveness. Finally, the simulation results demonstrate the capacity of our method in generating optimal paths with high quality.

Memory and survival after microbeam radiation therapy

International Nuclear Information System (INIS)

Schueltke, Elisabeth; Juurlink, Bernhard H.J.; Ataelmannan, Khalid; Laissue, Jean; Blattmann, Hans; Braeuer-Krisch, Elke; Bravin, Alberto; Minczewska, Joanna; Crosbie, Jeffrey; Taherian, Hadi; Frangou, Evan; Wysokinsky, Tomasz; Chapman, L. Dean; Griebel, Robert; Fourney, Daryl

2008-01-01

Background: Disturbances of memory function are frequently observed in patients with malignant brain tumours and as adverse effects after radiotherapy to the brain. Experiments in small animal models of malignant brain tumour using synchrotron-based microbeam radiation therapy (MRT) have shown a promising prolongation of survival times. Materials and methods: Two animal models of malignant brain tumour were used to study survival and memory development after MRT. Thirteen days after implantation of tumour cells, animals were submitted to MRT either with or without adjuvant therapy (buthionine-SR-sulfoximine = BSO or glutamine). We used two orthogonal 1-cm wide arrays of 50 microplanar quasiparallel microbeams of 25 μm width and a center-to-center distance of about 200 μm, created by a multislit collimator, with a skin entrance dose of 350 Gy for each direction. Object recognition tests were performed at day 13 after tumour cell implantation and in monthly intervals up to 1 year after tumour cell implantation. Results: In both animal models, MRT with and without adjuvant therapy significantly increased survival times. BSO had detrimental effects on memory function early after therapy, while administration of glutamine resulted in improved memory

Life-Cycle Models for Survivable Systems

National Research Council Canada - National Science Library

Linger, Richard

2002-01-01

.... Current software development life-cycle models are not focused on creating survivable systems, and exhibit shortcomings when the goal is to develop systems with a high degree of assurance of survivability...

Survival and development of Lymantria monacha (Lepidoptera: Lymantriidae) on North American and introduced Eurasian tree species.

Science.gov (United States)

Keena, M A

2003-02-01

Lymantria monacha (L.) (Lepidoptera: Lymantriidae), the nun moth, is a Eurasian pest of conifers that has potential for accidental introduction into North America. To project the potential host range of this insect if introduced into North America, survival and development of L. monacha on 26 North American and eight introduced Eurasian tree species were examined. Seven conifer species (Abies concolor, Picea abies, P. glauca, P. pungens, Pinus sylvestris with male cones, P. menziesii variety glance, and Tsuga canadensis) and six broadleaf species (Betula populifolia, Malus x domestica, Prunus serotiaa, Quercus lobata, Q. rubra, and Q. velutina) were suitable for L. monacha survival and development. Eleven of the host species tested were rated as intermediate in suitability, four conifer species (Larix occidentalis, P. nigra, P. ponderosa, P. strobus, and Pseudotsuga menziesii variety menziesii) and six broadleaf species (Carpinus caroliniana, Carya ovata, Fagus grandifolia, Populus grandidentata, Q. alba, and Tilia cordata) and the remaining 10 species tested were rated as poor (Acer rubrum, A. platanoidies, A. saccharum, F. americana, Juniperus virginiana, Larix kaempferi, Liriodendron tulipfera, Morus alba, P. taeda, and P. deltoides). The phenological state of the trees had a major impact on establishment, survival, and development of L. monacha on many of the tree species tested. Several of the deciduous tree species that are suitable for L. monacha also are suitable for L. dispar (L.) and L. mathura Moore. Establishment of L. monacha in North America would be catastrophic because of the large number of economically important tree species on which it can survive and develop, and the ability of mated females to fly and colonize new areas.

Survival patterns and hemopathological responses of dogs under continuous gamma irradiation

International Nuclear Information System (INIS)

Seed, T.M.; Fritz, T.E.; Tolle, D.V.; Poole, C.M.; Lombard, L.S.; Doyle, D.E.; Kaspar, L.V.; Cullen, S.M.; Carnes, B.A.

1983-01-01

Survival curves were constructed and analyzed relative to contributing hematopathological responses for groups of beagles exposed continuously for duration of life to low daily doses of whole body 60 Co gamma irradiation (27.3 rads/day to 4 rads/day). The survival curves versus time were progressively displaced toward longer survival as rates of exposure were reduced from the relatively high dose rate of 27.3 rads/day to the low dose rate of 4.0 rads/day. Average survival times increased from 57 days at 27.3 rads/day to 1830 days at 4.0 rads/day, representing fractional increased life-spans from 1.5% to 50.8%, respectively. Survival curves versus total dose were markedly displaced along the cumulative radiation dose axis at the extreme dose rates (i.e., 27.3 and 4.0 rads/day), but not at the intermediate dose rates (i.e., 13.4 and 7.9 rads/day) in which the upper linear portions of the survival curves are superimposed. From these dose-dependent survival curves, LD 50 values for whole body gamma irradiation, delivered chronically at 27.3, 13.4, 7.9, and 4.0 rads per day were estimated to be 1442, 2124, 2039, and 7161 rads, respectively. Both time- and dose-dependent survival curves for the intermediate dose rates, in contrast to the extreme dose rates, exhibited pronounced transitions in the lethality rate below the 50% survival level. These lethality rate transitions occurred at approx. 2500 rads of accumulated dose and were attributed to a shift in the spectrum of developing hematopathologies: namely, from a predominance of the acutely ablative radiation-induced lymphohematopoietic syndromes (i.e., septicemias and aplastic anemias) to a predominance of the late arising hematopoietic neoplasias (myelogenous leukemia and related myeloproliferative disorders)

Systematic review of survival time in experimental mouse stroke with impact on reliability of infarct estimation

DEFF Research Database (Denmark)

Klarskov, Carina Kirstine; Klarskov, Mikkel Buster; Hasseldam, Henrik

2016-01-01

infarcts with more substantial edema. Purpose: This paper will give an overview of previous studies of experimental mouse stroke, and correlate survival time to peak time of edema formation. Furthermore, investigations of whether the included studies corrected the infarct measurements for edema...... of reasons for the translational problems from mouse experimental stroke to clinical trials probably exists, including infarct size estimations around the peak time of edema formation. Furthermore, edema is a more prominent feature of stroke in mice than in humans, because of the tendency to produce larger...... of the investigated process. Our findings indicate a need for more research in this area, and establishment of common correction methodology....

Meta-analysis of single-arm survival studies: a distribution-free approach for estimating summary survival curves with random effects.

Science.gov (United States)

Combescure, Christophe; Foucher, Yohann; Jackson, Daniel

2014-07-10

In epidemiologic studies and clinical trials with time-dependent outcome (for instance death or disease progression), survival curves are used to describe the risk of the event over time. In meta-analyses of studies reporting a survival curve, the most informative finding is a summary survival curve. In this paper, we propose a method to obtain a distribution-free summary survival curve by expanding the product-limit estimator of survival for aggregated survival data. The extension of DerSimonian and Laird's methodology for multiple outcomes is applied to account for the between-study heterogeneity. Statistics I(2)  and H(2) are used to quantify the impact of the heterogeneity in the published survival curves. A statistical test for between-strata comparison is proposed, with the aim to explore study-level factors potentially associated with survival. The performance of the proposed approach is evaluated in a simulation study. Our approach is also applied to synthesize the survival of untreated patients with hepatocellular carcinoma from aggregate data of 27 studies and synthesize the graft survival of kidney transplant recipients from individual data from six hospitals. Copyright © 2014 John Wiley & Sons, Ltd.

Preoperative diffusion-weighted imaging of single brain metastases correlates with patient survival times.

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Anna Sophie Berghoff

Full Text Available BACKGROUND: MRI-based diffusion-weighted imaging (DWI visualizes the local differences in water diffusion in vivo. The prognostic value of DWI signal intensities on the source images and apparent diffusion coefficient (ADC maps respectively has not yet been studied in brain metastases (BM. METHODS: We included into this retrospective analysis all patients operated for single BM at our institution between 2002 and 2010, in whom presurgical DWI and BM tissue samples were available. We recorded relevant clinical data, assessed DWI signal intensity and apparent diffusion coefficient (ADC values and performed histopathological analysis of BM tissues. Statistical analyses including uni- and multivariate survival analyses were performed. RESULTS: 65 patients (34 female, 31 male with a median overall survival time (OS of 15 months (range 0-99 months were available for this study. 19 (29.2% patients presented with hyper-, 3 (4.6% with iso-, and 43 (66.2% with hypointense DWI. ADCmean values could be determined in 32 (49.2% patients, ranged from 456.4 to 1691.8*10⁻⁶ mm²/s (median 969.5 and showed a highly significant correlation with DWI signal intensity. DWI hyperintensity correlated significantly with high amount of interstitial reticulin deposition. In univariate analysis, patients with hyperintense DWI (5 months and low ADCmean values (7 months had significantly worse OS than patients with iso/hypointense DWI (16 months and high ADCmean values (30 months, respectively. In multivariate survival analysis, high ADCmean values retained independent statistical significance. CONCLUSIONS: Preoperative DWI findings strongly and independently correlate with OS in patients operated for single BM and are related to interstitial fibrosis. Inclusion of DWI parameters into established risk stratification scores for BM patients should be considered.

Abundance of early functional HIV-specific CD8+ T cells does not predict AIDS-free survival time.

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Ingrid M M Schellens

Full Text Available BACKGROUND: T-cell immunity is thought to play an important role in controlling HIV infection, and is a main target for HIV vaccine development. HIV-specific central memory CD8(+ and CD4(+ T cells producing IFNgamma and IL-2 have been associated with control of viremia and are therefore hypothesized to be truly protective and determine subsequent clinical outcome. However, the cause-effect relationship between HIV-specific cellular immunity and disease progression is unknown. We investigated in a large prospective cohort study involving 96 individuals of the Amsterdam Cohort Studies with a known date of seroconversion whether the presence of cytokine-producing HIV-specific CD8(+ T cells early in infection was associated with AIDS-free survival time. METHODS AND FINDINGS: The number and percentage of IFNgamma and IL-2 producing CD8(+ T cells was measured after in vitro stimulation with an overlapping Gag-peptide pool in T cells sampled approximately one year after seroconversion. Kaplan-Meier survival analysis and Cox proportional hazard models showed that frequencies of cytokine-producing Gag-specific CD8(+ T cells (IFNgamma, IL-2 or both shortly after seroconversion were neither associated with time to AIDS nor with the rate of CD4(+ T-cell decline. CONCLUSIONS: These data show that high numbers of functional HIV-specific CD8(+ T cells can be found early in HIV infection, irrespective of subsequent clinical outcome. The fact that both progressors and long-term non-progressors have abundant T cell immunity of the specificity associated with low viral load shortly after seroconversion suggests that the more rapid loss of T cell immunity observed in progressors may be a consequence rather than a cause of disease progression.

Conditional survival of patients with diffuse large B-cell lymphoma

DEFF Research Database (Denmark)

Møller, Michael Boe; Pedersen, Niels Tinggaard; Christensen, Bjarne E

2006-01-01

BACKGROUND: Prognosis of lymphoma patients is usually estimated at the time of diagnosis and the estimates are guided by the International Prognostic Index (IPI). However, conditional survival estimates are more informative clinically, as they consider those patients only who have already survive...... survival probability provides more accurate prognostic information than the conventional survival rate estimated from the time of diagnosis.......BACKGROUND: Prognosis of lymphoma patients is usually estimated at the time of diagnosis and the estimates are guided by the International Prognostic Index (IPI). However, conditional survival estimates are more informative clinically, as they consider those patients only who have already survived...... a period of time after treatment. Conditional survival data have not been reported for lymphoma patients. METHODS: Conditional survival was estimated for 1209 patients with diffuse large B-cell lymphoma (DLBCL) from the population-based LYFO registry of the Danish Lymphoma Group. The Kaplan-Meier method...

Development of rations for the enhanced survival of salmon

International Nuclear Information System (INIS)

Ewing, R.D.; Lagasse, J.P.

1990-12-01

The nutritional quality of feed plays an important role in determining the health and ''fitness'' of smolts. Commercial fish meal, the major source of protein in salmon rations, may be reduced in quality from poor drying techniques during manufacture. Dietary stress in the hatchery may result. This investigation tests the hypothesis that protein quality of fish rations can influence the survival of smolts and the ultimate return of adults. The test involves a comparison between performances of coho (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) reared on rations containing very high quality protein derived from vacuum dried meals and those of fish reared on commercial rations, with commercial fish meal as a source of protein. Survival and return of several brood years of test and control fish are used to measure the influence of ration on survival. This report includes recovery data from these marked fish collected 1982 through September 1990

Survival Processing Enhances Visual Search Efficiency.

Science.gov (United States)

Cho, Kit W

2018-05-01

Words rated for their survival relevance are remembered better than when rated using other well-known memory mnemonics. This finding, which is known as the survival advantage effect and has been replicated in many studies, suggests that our memory systems are molded by natural selection pressures. In two experiments, the present study used a visual search task to examine whether there is likewise a survival advantage for our visual systems. Participants rated words for their survival relevance or for their pleasantness before locating that object's picture in a search array with 8 or 16 objects. Although there was no difference in search times among the two rating scenarios when set size was 8, survival processing reduced visual search times when set size was 16. These findings reflect a search efficiency effect and suggest that similar to our memory systems, our visual systems are also tuned toward self-preservation.

A flexible and coherent test/estimation procedure based on restricted mean survival times for censored time-to-event data in randomized clinical trials.

Science.gov (United States)

Horiguchi, Miki; Cronin, Angel M; Takeuchi, Masahiro; Uno, Hajime

2018-04-22

In randomized clinical trials where time-to-event is the primary outcome, almost routinely, the logrank test is prespecified as the primary test and the hazard ratio is used to quantify treatment effect. If the ratio of 2 hazard functions is not constant, the logrank test is not optimal and the interpretation of hazard ratio is not obvious. When such a nonproportional hazards case is expected at the design stage, the conventional practice is to prespecify another member of weighted logrank tests, eg, Peto-Prentice-Wilcoxon test. Alternatively, one may specify a robust test as the primary test, which can capture various patterns of difference between 2 event time distributions. However, most of those tests do not have companion procedures to quantify the treatment difference, and investigators have fallen back on reporting treatment effect estimates not associated with the primary test. Such incoherence in the "test/estimation" procedure may potentially mislead clinicians/patients who have to balance risk-benefit for treatment decision. To address this, we propose a flexible and coherent test/estimation procedure based on restricted mean survival time, where the truncation time τ is selected data dependently. The proposed procedure is composed of a prespecified test and an estimation of corresponding robust and interpretable quantitative treatment effect. The utility of the new procedure is demonstrated by numerical studies based on 2 randomized cancer clinical trials; the test is dramatically more powerful than the logrank, Wilcoxon tests, and the restricted mean survival time-based test with a fixed τ, for the patterns of difference seen in these cancer clinical trials. Copyright © 2018 John Wiley & Sons, Ltd.

Time-course mortality and radiosensitivity indices in Tribolium spp. developing from irradiated pupae

International Nuclear Information System (INIS)

Hasan, Md Mahbub

1999-01-01

Effects of gamma irradiation (1-5 Krad) on the time-course mortality and radiosensitivity indices in adults of Tribolium anaphe, T. brevicornis, T. castaneum, T. destructor, T. freemani developing from irradiated 1 day old and pre-emergence (4-5 day old) pupae were studied. Adult longevity was significantly (P<0.001) affected by irradiation and was linearly dose dependent. T. destructor was markedly more radioresistant than the other species at all dose levels and had a longer life expectancy. The mean survival times of adults developing from irradiated early and late pupae were shorter in females than in males for all the species. The radiosensitivity indices did not vary widely among the species and these values decreased as the dose increased in all the species which clearly indicate that the resistance of the species was dose-dependent. (author)

Survival rate of breast cancer patients in Malaysia: a population-based study.

Science.gov (United States)

Abdullah, Nor Aini; Wan Mahiyuddin, Wan Rozita; Muhammad, Nor Asiah; Ali, Zainudin Mohamad; Ibrahim, Lailanor; Ibrahim Tamim, Nor Saleha; Mustafa, Amal Nasir; Kamaluddin, Muhammad Amir

2013-01-01

Breast cancer is the most common cancer among Malaysian women. Other than hospital-based results, there are no documented population-based survival rates of Malaysian women for breast cancers. This population- based retrospective cohort study was therefore conducted. Data were obtained from Health Informatics Centre, Ministry of Health Malaysia, National Cancer Registry and National Registration Department for the period from 1st Jan 2000 to 31st December 2005. Cases were captured by ICD-10 and linked to death certificates to identify the status. Only complete data were analysed. Survival time was calculated from the estimated date of diagnosis to the date of death or date of loss to follow-up. Observed survival rates were estimated by Kaplan- Meier method using SPSS Statistical Software version 17. A total of 10,230 complete data sets were analysed. The mean age at diagnosis was 50.6 years old. The overall 5-year survival rate was 49% with median survival time of 68.1 months. Indian women had a higher survival rate of 54% compared to Chinese women (49%) and Malays (45%). The overall 5-year survival rate of breast cancer patient among Malaysian women was still low for the cohort of 2000 to 2005 as compared to survival rates in developed nations. Therefore, it is necessary to enhance the strategies for early detection and intervention.

Cancer survival among Alaska Native people.

Science.gov (United States)

Nash, Sarah H; Meisner, Angela L W; Zimpelman, Garrett L; Barry, Marc; Wiggins, Charles L

2018-03-26

Recent cancer survival trends among American Indian and Alaska Native (AN) people are not well understood; survival has not been reported among AN people since 2001. This study examined cause-specific survival among AN cancer patients for lung, colorectal, female breast, prostate, and kidney cancers. It evaluated whether survival differed between cancers diagnosed in 1992-2002 (the earlier period) and cancers diagnosed in 2003-2013 (the later period) and by the age at diagnosis (<65 vs ≥65 years), stage at diagnosis (local or regional/distant/unknown), and sex. Kaplan-Meier and Cox proportional hazards models were used to estimate univariate and multivariate-adjusted cause-specific survival for each cancer. An improvement was observed in 5-year survival over time from lung cancer (hazard ratio [HR] for the later period vs the earlier period, 0.83; 95% confidence interval [CI], 0.72-0.97), and a marginally nonsignificant improvement was observed for colorectal cancer (HR, 0.81; 95% CI, 0.66-1.01). Site-specific differences in survival were observed by age and stage at diagnosis. This study presents the first data on cancer survival among AN people in almost 2 decades. During this time, AN people have experienced improvements in survival from lung and colorectal cancers. The reasons for these improvements may include increased access to care (including screening) as well as improvements in treatment. Improving cancer survival should be a priority for reducing the burden of cancer among AN people and eliminating cancer disparities. Cancer 2018. © 2018 American Cancer Society. © 2018 American Cancer Society.

Survival of influenza virus on banknotes.

Science.gov (United States)

Thomas, Yves; Vogel, Guido; Wunderli, Werner; Suter, Patricia; Witschi, Mark; Koch, Daniel; Tapparel, Caroline; Kaiser, Laurent

2008-05-01

Successful control of a viral disease requires knowledge of the different vectors that could promote its transmission among hosts. We assessed the survival of human influenza viruses on banknotes given that billions of these notes are exchanged daily worldwide. Banknotes were experimentally contaminated with representative influenza virus subtypes at various concentrations, and survival was tested after different time periods. Influenza A viruses tested by cell culture survived up to 3 days when they were inoculated at high concentrations. The same inoculum in the presence of respiratory mucus showed a striking increase in survival time (up to 17 days). Similarly, B/Hong Kong/335/2001 virus was still infectious after 1 day when it was mixed with respiratory mucus. When nasopharyngeal secretions of naturally infected children were used, influenza virus survived for at least 48 h in one-third of the cases. The unexpected stability of influenza virus in this nonbiological environment suggests that unusual environmental contamination should be considered in the setting of pandemic preparedness.

Survival of Influenza Virus on Banknotes▿

Science.gov (United States)

Thomas, Yves; Vogel, Guido; Wunderli, Werner; Suter, Patricia; Witschi, Mark; Koch, Daniel; Tapparel, Caroline; Kaiser, Laurent

2008-01-01

Successful control of a viral disease requires knowledge of the different vectors that could promote its transmission among hosts. We assessed the survival of human influenza viruses on banknotes given that billions of these notes are exchanged daily worldwide. Banknotes were experimentally contaminated with representative influenza virus subtypes at various concentrations, and survival was tested after different time periods. Influenza A viruses tested by cell culture survived up to 3 days when they were inoculated at high concentrations. The same inoculum in the presence of respiratory mucus showed a striking increase in survival time (up to 17 days). Similarly, B/Hong Kong/335/2001 virus was still infectious after 1 day when it was mixed with respiratory mucus. When nasopharyngeal secretions of naturally infected children were used, influenza virus survived for at least 48 h in one-third of the cases. The unexpected stability of influenza virus in this nonbiological environment suggests that unusual environmental contamination should be considered in the setting of pandemic preparedness. PMID:18359825

Randomized, placebo controlled study of the effect of propentofylline on survival time and quality of life of cats with feline infectious peritonitis.

Science.gov (United States)

Fischer, Y; Ritz, S; Weber, K; Sauter-Louis, C; Hartmann, K

2011-01-01

Currently there is no drug proven to effectively treat cats with feline infectious peritonitis (FIP). Propentofylline (PPF) can decrease vasculitis, and therefore prolong survival time in cats with FIP, and increase their quality of life. Twenty-three privately owned cats with FIP. Placebo-controlled double-blind trial. FIP was confirmed by histology or immunostaining of feline coronavirus (FCoV) antigen in effusion or tissue macrophages or both. The cats were randomly selected for treatment with either PPF or placebo. All cats received additional treatment with glucocorticoids, antibiotics, and low molecular weight heparin according to methods. There was no statistically significant difference in the survival time of cats treated with PPF (8 days, 95% CI 5.4-10.6) versus placebo (7.5 days, 95% CI 4.4-9.6). The median survival time of all cats was 8 days (4-36 days). There was neither a difference in quality of life (day 7, P = .892), in the amount of effusion (day 7, P = .710), the tumor necrosis factor-alpha (TNF-α) concentration (day 7, P = .355), nor in any other variable investigated in this study, including a complete blood count, and a small animal biochemistry profile. This study did not detect an effect of PPF on the survival time, the quality of life, or any clinical or laboratory parameter in cats with FIP. Therefore, PPF does not appear to be an effective treatment option in cats with a late stage of the disease FIP. Copyright © 2011 by the American College of Veterinary Internal Medicine.

The effect of donor gender on renal allograft survival.

Science.gov (United States)

Neugarten, J; Srinivas, T; Tellis, V; Silbiger, S; Greenstein, S

1996-02-01

Donor gender plays a role in the outcome of renal transplantation, but the mechanisms responsible for this effect are unclear. In this study, actuarial graft survival in 1049 recipients transplanted at Montefiore Medical Center between 1979 and 1994 was examined. It was found that donor gender had no influence on graft survival in recipients treated with precyclosporine immunosuppressive agents. In contrast, graft survival time was greater in cyclosporine-treated recipients of male donor kidneys compared with female kidneys (p demand results in hyperfiltration-mediated glomerular injury and that this is responsible for reduced survival time of female allografts. Any hypothesis purporting to explain gender-related differences in graft survival time must take into account this study's observations that the donor-gender effect was observed only in cyclosporine-treated recipients, was not seen in African-American donors, appeared soon after renal transplantation, and did not increase progressively with time. These observations are most consistent with the hypothesis that gender-related differences in graft survival time may reflect differences in susceptibility to cyclosporine nephrotoxicity or differences in the therapeutic response to cyclosporine.

On the relationship between tumour growth rate and survival in non-small cell lung cancer

Directory of Open Access Journals (Sweden)

Hitesh B. Mistry

2017-11-01

Full Text Available A recurrent question within oncology drug development is predicting phase III outcome for a new treatment using early clinical data. One approach to tackle this problem has been to derive metrics from mathematical models that describe tumour size dynamics termed re-growth rate and time to tumour re-growth. They have shown to be strong predictors of overall survival in numerous studies but there is debate about how these metrics are derived and if they are more predictive than empirical end-points. This work explores the issues raised in using model-derived metric as predictors for survival analyses. Re-growth rate and time to tumour re-growth were calculated for three large clinical studies by forward and reverse alignment. The latter involves re-aligning patients to their time of progression. Hence, it accounts for the time taken to estimate re-growth rate and time to tumour re-growth but also assesses if these predictors correlate to survival from the time of progression. I found that neither re-growth rate nor time to tumour re-growth correlated to survival using reverse alignment. This suggests that the dynamics of tumours up until disease progression has no relationship to survival post progression. For prediction of a phase III trial I found the metrics performed no better than empirical end-points. These results highlight that care must be taken when relating dynamics of tumour imaging to survival and that bench-marking new approaches to existing ones is essential.

A nomogram for predicting survival in patients with breast cancer brain metastasis.

Science.gov (United States)

Huang, Zhou; Sun, Bing; Wu, Shikai; Meng, Xiangying; Cong, Yang; Shen, Ge; Song, Santai

2018-05-01

Brain metastasis (BM) is common in patients with breast cancer. Predicting patient survival is critical for the clinical management of breast cancer brain metastasis (BCBM). The present study was designed to develop and evaluate a prognostic model for patients with newly diagnosed BCBM. Based on the clinical data of patients with BCBM treated in the Affiliated Hospital of Academy of Military Medical Sciences (Beijing, China) between 2002 and 2014, a nomogram was developed to predict survival using proportional hazards regression analysis. The model was validated internally by bootstrapping, and the concordance index (c-index) was calculated. A calibration curve and c-index were used to evaluate discriminatory and predictive ability, in order to compare the nomogram with widely used models, including recursive partitioning analysis (RPA), graded prognostic assessment (GPA) and breast-graded prognostic assessment (Breast-GPA). A total of 411 patients with BCBM were included in the development of this predictive model. The median overall survival time was 14.1 months. Statistically significant predictors for patient survival included biological subtype, Karnofsky performance score, leptomeningeal metastasis, extracranial metastasis, the number of brain metastases and disease-free survival. A nomogram for predicting 1- and 2-year overall survival rates was constructed, which exhibited good accuracy in predicting overall survival with a concordance index of 0.735. This model outperformed RPA, GPA and Breast-GPA, based on the comparisons of the c-indexes. The nomogram constructed based on a multiple factor analysis was able to more accurately predict the individual survival probability of patients with BCBM, compared with existing models.

Hyperthermic survival of Chinese hamster ovary cells as a function of cellular population density at the time of plating

International Nuclear Information System (INIS)

Highfield, D.P.; Holahan, E.V.; Holahan, P.K.; Dewey, W.C.

1984-01-01

The survival of synchronous G 1 or asynchronous Chinese hamster ovary cells in vitro to heat treatment may depend on the cellular population density at the time of heating and/or as the cells are cultured after heating. The addition of lethally irradiated feeder cells may increase survival at 10 -3 by as much as 10- to 100-fold for a variety of conditions when cells are heated either in suspension culture or as monolayers with or without trypsinization. The protective effect associated with feeder cells appears to be associated with close cell-to-cell proximity. However, when cells are heated without trypsinization about 24 hr or later after plating, when adaptation to monolayer has occurred, the protective effect is reduced; i.e., addition of feeder cells enhances survival much less, for example, about 2- to 3-fold at 10 -2 -10 -3 survival. Also, the survival of a cell to heat is independent of whether the neighboring cell in a microcolony is destined to live or die. Finally, if protective effects associated with cell density do occur and are not controlled, serious artifacts can result as the interaction of heat and radiation is studied; for example, survival curves can be moved upward, and thus changed in shape as the number of cells plated is increased with an increase in the hyperthermic treatment or radiation dose following hyperthermia. Therefore, to understand mechanisms and to obtain information relevant to populations of cells in close proximity, such as those in vivo, these cellular population density effects should be considered and understood

Relationships among the cervical mucus urea and acetone, accuracy of insemination timing, and sperm survival in Holstein cows.

Science.gov (United States)

Beran, J; Stádník, L; Ducháček, J; Okrouhlá, M; Doležalová, M; Kadlecová, V; Ptáček, M

2013-11-01

The objectives of this study were to evaluate the relationships among urea and acetone content in cows' cervical mucus (CM), its crystallization type (CT) and sperm survival (SS) after timed AI. Samples of CM were collected from 192 Holstein cows treated by Ovsynch(®) protocol. Analysis of the urea and acetone content for identification of the metabolic status, the arborization test for evaluation of insemination timing and the short-term heat test of SS for assessment of its suitability as a biological matrix were performed. The data set was analyzed by the GLM procedure using SAS(®). The results documented the existence of substantial differences in individual response to the Ovsynch(®) protocol causing insemination of 55.2% cows at an inappropriate time. The urea content was found as a possible indicator of a cow's metabolism and/or of insemination timing, concentrations of less than 500 mg/L corresponded (Pacetone content on SS were determined. The greatest values of SS were detected in cows with an expected response to precisely timed oestrus documented by the corresponding CT. Greater values of urea (>260 mg/L) and acetone (>5mg/L) negatively affected SS as well (P<0.05-0.01). The results confirmed that the accuracy of insemination timing can be affected by the metabolism intensity, just as CM quality directly influences sperm survival. Copyright © 2013 Elsevier B.V. All rights reserved.

Survival of Salmonella Newport in oysters.

Science.gov (United States)

Morrison, Christopher M; Armstrong, Alexandra E; Evans, Sanford; Mild, Rita M; Langdon, Christopher J; Joens, Lynn A

2011-08-02

Salmonella enterica is the leading cause of laboratory-confirmed foodborne illness in the United States and raw shellfish consumption is a commonly implicated source of gastrointestinal pathogens. A 2005 epidemiological study done in our laboratory by Brands et al., showed that oysters in the United States are contaminated with Salmonella, and in particular, a specific strain of the Newport serovar. This work sought to further investigate the host-microbe interactions between Salmonella Newport and oysters. A procedure was developed to reliably and repeatedly expose oysters to enteric bacteria and quantify the subsequent levels of bacterial survival. The results show that 10 days after an exposure to Salmonella Newport, an average concentration of 3.7 × 10(3)CFU/g remains within the oyster meat, and even after 60 days there still can be more than 10(2)CFU/g remaining. However, the strain of Newport that predominated in the market survey done by Brands et al. does not survive within oysters or the estuarine environment better than any other strains of Salmonella we tested. Using this same methodology, we compared Salmonella Newport's ability to survive within oysters to a non-pathogenic strain of E. coli and found that after 10 days the concentration of Salmonella was 200-times greater than that of E. coli. We also compared those same strains of Salmonella and E. coli in a depuration process to determine if a constant 120 L/h flux of clean seawater could significantly reduce the concentration of bacteria within oysters and found that after 3 days the oysters retained over 10(4)CFU/g of Salmonella while the oysters exposed to the non-pathogenic strain of E. coli contained 100-times less bacteria. Overall, the results of this study demonstrate that any of the clinically relevant serovars of Salmonella can survive within oysters for significant periods of time after just one exposure event. Based on the drastic differences in survivability between Salmonella and a non

Introduction to SURPH.1 analysis of release-recapture data for survival studies

International Nuclear Information System (INIS)

Smith, S.G.; Skalski, J.R.; Schlechte, J.W.; Hoffmann, A.; Cassen, V.

1994-12-01

Program SURPH is the culmination of several years of research to develop a comprehensive computer program to analyze survival studies of fish and wildlife populations. Development of this software was motivated by the advent of the PIT-tag (Passive Integrated Transponder) technology that permits the detection of salmonid smolt as they pass through hydroelectric facilities on the Snake and Columbia Rivers in the Pacific Northwest. Repeated detections of individually tagged smolt and analysis of their capture-histories permits estimates of downriver survival probabilities. Eventual installation of detection facilities at adult fish ladders will also permit estimation of ocean survival and upstream survival of returning salmon using the statistical methods incorporated in SURPH.1. However, the utility of SURPH.1 far exceeds solely the analysis of salmonid tagging studies. Release-recapture and radiotelemetry studies from a wide range of terrestrial and aquatic species have been analyzed using SURPH.1 to estimate discrete time survival probabilities and investigate survival relationships. The interactive computing environment of SURPH.1 was specifically developed to allow researchers to investigate the relationship between survival and capture processes and environmental, experimental and individual-based covariates. Program SURPH.1 represents a significant advancement in the ability of ecologists to investigate the interplay between morphologic, genetic, environmental and anthropogenic factors on the survival of wild species. It is hoped that this better understanding of risk factors affecting survival will lead to greater appreciation of the intricacies of nature and to improvements in the management of wild resources. This technical report is an introduction to SURPH.1 and provides a user guide for both the UNIX and MS-Windows reg-sign applications of the SURPH software

Development of a Survivable Cloud Multi-Robot Framework for Heterogeneous Environments

Directory of Open Access Journals (Sweden)

Isaac Osunmakinde

2014-10-01

Full Text Available Cloud robotics is a paradigm that allows for robots to offload computationally intensive and data storage requirements into the cloud by providing a secure and customizable environment. The challenge for cloud robotics is the inherent problem of cloud disconnection. A major assumption made in the development of the current cloud robotics frameworks is that the connection between the cloud and the robot is always available. However, for multi-robots working in heterogeneous environments, the connection between the cloud and the robots cannot always be guaranteed. This work serves to assist with the challenge of disconnection in cloud robotics by proposing a survivable cloud multi-robotics (SCMR framework for heterogeneous environments. The SCMR framework leverages the combination of a virtual ad hoc network formed by robot-to-robot communication and a physical cloud infrastructure formed by robot-to-cloud communications. The quality of service (QoS on the SCMR framework was tested and validated by determining the optimal energy utilization and time of response (ToR on drivability analysis with and without cloud connection. The design trade-off, including the result, is between the computation energy for the robot execution and the offloading energy for the cloud execution.

Investigation of Growth and Survival of Transplanted Plane and Pine Trees According to IBA Application, Tree Age, Transplanting Time and Method

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N. Etemadi

2015-03-01

Full Text Available The major problems in transplanting the landscape trees are high level of mortality and low establishment rate of transplanted trees, especially in the first year. In order to achieve the best condition for successful transplanting of pine and plane trees in Isfahan landscape, the present study was carried out based on a completely randomized block design with four replicates and three treatments including transplanting method (balled and burlapped and bare root, tree age (immature and mature and IBA application (0 and 150 mg/L. Trees were transplanted during 2009 and 2010 in three times (dormant season, early and late growing season. Survival rate and Relative Growth Rate index based on tree height (RGRH and trunk diameter (RGRD were measured during the first and second years. Trees transplanted early in the growing season showed the most survival percentage during the two years, as compared to other transplanting dates. Survival of Balled and burlapped and immature transplanted trees was significantly greater than bare root or mature trees. The significant effect of age treatment was continued in the second year. IBA treatment had no effect on survival rate of the studied species. Balled and burlapped and immature transplanted pine trees also had higher RGRH and RGRD compared to bare root or mature trees. According to the results of this study, early growing season is the best time for transplanting pine and plane trees. Also, transplanting of immature trees using balled and burlapped method is recommended to increase the survival and establishment rate.

Western bean cutworm survival and the development of economic injury levels and economic thresholds in field corn.

Science.gov (United States)

Paula-Moraes, S; Hunt, T E; Wright, R J; Hein, G L; Blankenship, E E

2013-06-01

Western bean cutworm, Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), is a native pest of dry beans (Phaseolus vulgaris L.) and corn (Zea mays L.). Historically, the western bean cutworm was distributed in the western United States, but since 1999 eastward expansion has been observed. In corn, economic impact is caused by larval ear feeding. Information on western bean cutworm biology, ecology, and economic impact is relatively limited, and the development of economic injury levels (EILs) and economic thresholds (ETs) is required for more effective management. Studies during 2008-2011, across three ecoregions of Nebraska, sought to characterize western bean cutworm survival and development of EILs and ETs. Calculations of EILs and ETs incorporated the dynamics of corn price, management cost, and pest survival. The results from the current study demonstrated low larval survival of this species (1.51-12.82%). The mean yield loss from one western bean cutworm larva per plant was 945.52 kg/ha (15.08 bu/acre), based on 74,100 plants per ha. Economic thresholds are expressed as a percentage of plants with at least one egg mass. This study is the first study that explicitly incorporates variable management costs and crop values into western bean cutworm EIL calculations, and larval survival into ET calculations.

Clustered survival data with left-truncation

DEFF Research Database (Denmark)

Eriksson, Frank; Martinussen, Torben; Scheike, Thomas H.

2015-01-01

Left-truncation occurs frequently in survival studies, and it is well known how to deal with this for univariate survival times. However, there are few results on how to estimate dependence parameters and regression effects in semiparametric models for clustered survival data with delayed entry....... Surprisingly, existing methods only deal with special cases. In this paper, we clarify different kinds of left-truncation and suggest estimators for semiparametric survival models under specific truncation schemes. The large-sample properties of the estimators are established. Small-sample properties...

Survival and Psychomotor Development With Early Betaine Treatment in Patients With Severe Methylenetetrahydrofolate Reductase Deficiency

NARCIS (Netherlands)

Diekman, Eugene F.; de Koning, Tom J.; Verhoeven-Duif, Nanda M.; Rovers, Maroeska M.; van Hasselt, Peter M.

IMPORTANCE The impact of betaine treatment on outcome in patients with severe methylenetetrahydrofolate reductase (MTHFR) deficiency is presently unclear. OBJECTIVE To investigate the effect of betaine treatment on development and survival in patients with severe MTHFR deficiency. DATA SOURCES

Survival and psychomotor development with early betaine treatment in patients with severe methylenetetrahydrofolate reductase deficiency

NARCIS (Netherlands)

Diekman, E.F.; Koning, T.J. de; Verhoeven-Duif, N.M.; Rovers, M.M.; Hasselt, P.M. van

2014-01-01

IMPORTANCE The impact of betaine treatment on outcome in patients with severe methylenetetrahydrofolate reductase (MTHFR) deficiency is presently unclear. OBJECTIVE To investigate the effect of betaine treatment on development and survival in patients with severe MTHFR deficiency. DATA SOURCES

Survivability on the Island of Spice: The Development of the UH-60 Blackhawk and Its Baptism of Fire in Operation Urgent Fury

Science.gov (United States)

2015-06-12

SURVIVABILITY ON THE ISLAND OF SPICE : THE DEVELOPMENT OF THE UH-60 BLACKHAWK AND ITS BAPTISM OF FIRE IN OPERATION URGENT FURY......THESIS APPROVAL PAGE Name of Candidate: Major Matthew G. Easley Thesis Title: Survivability on the Island of Spice : The Development of the UH

Child mortality inequalities across Rwanda districts: a geoadditive continuous-time survival analysis

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François Niragire

2017-05-01

Full Text Available Child survival programmes are efficient when they target the most significant and area-specific factors. This study aimed to assess the key determinants and spatial variation of child mortality at the district level in Rwanda. Data from the 2010 Rwanda Demographic and Health Survey were analysed for 8817 live births that occurred during five years preceding the survey. Out of the children born, 433 had died before survey interviews were carried out. A full Bayesian geo-additive continuous-time hazard model enabled us to maximise data utilisation and hence improve the accuracy of our estimates. The results showed substantial district- level spatial variation in childhood mortality in Rwanda. District-specific spatial characteristics were particularly associated with higher death hazards in two districts: Musanze and Nyabihu. The model estimates showed that there were lower death rates among children from households of medium and high economic status compared to those from low-economic status households. Factors, such as four antenatal care visits, delivery at a health facility, prolonged breastfeeding and mothers younger than 31 years were associated with lower child death rates. Long preceding birth intervals were also associated with fewer hazards. For these reasons, programmes aimed at reducing child mortality gaps between districts in Rwanda should target maternal factors and take into consideration district-specific spatial characteristics. Further, child survival gains require strengthening or scaling-up of existing programmes pertaining to access to, and utilisation of maternal and child health care services as well as reduction of the household gap in the economic status.

Child mortality inequalities across Rwanda districts: a geoadditive continuous-time survival analysis.

Science.gov (United States)

Niragire, François; Achia, Thomas N O; Lyambabaje, Alexandre; Ntaganira, Joseph

2017-05-11

Child survival programmes are efficient when they target the most significant and area-specific factors. This study aimed to assess the key determinants and spatial variation of child mortality at the district level in Rwanda. Data from the 2010 Rwanda Demographic and Health Survey were analysed for 8817 live births that occurred during five years preceding the survey. Out of the children born, 433 had died before survey interviews were carried out. A full Bayesian geo-additive continuous-time hazard model enabled us to maximise data utilisation and hence improve the accuracy of our estimates. The results showed substantial district- level spatial variation in childhood mortality in Rwanda. District-specific spatial characteristics were particularly associated with higher death hazards in two districts: Musanze and Nyabihu. The model estimates showed that there were lower death rates among children from households of medium and high economic status compared to those from low-economic status households. Factors, such as four antenatal care visits, delivery at a health facility, prolonged breastfeeding and mothers younger than 31 years were associated with lower child death rates. Long preceding birth intervals were also associated with fewer hazards. For these reasons, programmes aimed at reducing child mortality gaps between districts in Rwanda should target maternal factors and take into consideration district-specific spatial characteristics. Further, child survival gains require strengthening or scaling-up of existing programmes pertaining to access to, and utilisation of maternal and child health care services as well as reduction of the household gap in the economic status.

Storage condition of mulberry branches (Morus sp. in the survival, development and production of Bombyx mori L.

Directory of Open Access Journals (Sweden)

Antonio José Porto

2012-02-01

Full Text Available The study was carried with the objective of evaluate the survival, development and cocoons production of silkworm fed with mulberry leaves (Cultivar IZ 56/4 from branches stored in warehouse(24 hours or stored in the system of covering with wet cloth and immersion of bases in water, for a period of 72 hours. It was used a completely randomized design, with two treatments and six replications. Caterpillars fed with mulberry leaves from branches stored in the system of covering and immersion for 72 hours had conditions suitable for survival, development and production of cocoon, not differing from those who received leaves from branches stored in the warehouse.

Factors affecting survival of women diagnosed with breast cancer in El-Minia Governorate, Egypt.

Science.gov (United States)

Seedhom, Amany Edward; Kamal, Nashwa Nabil

2011-07-01

This study was conducted to determine breast cancer survival time and the association between breast cancer survival and socio-demographic and pathologic factors among women, in El-Minia, Egypt. While there has been much researches regarding prognostic factors for breast cancer but the majority of these studies were from developed countries. El-Minia has a population of approximately 4 million. To date, no research has been performed to determine breast cancer survival and the factors affecting it in El-minia. This retrospective study used data obtained from the cancer registry in the National Institute of Oncology in El-Minia and included 1207 women diagnosed with first primary breast cancer between 1(st) January 2005 and 31(st) December 2009 and followed to 30(th) June 2010. The association between survival and sociodemographic and pathological factors and distant metastasis at diagnosis, and treatment options was investigated using unifactorial chi-square test and multi-factorial (Cox regression) analyses. Kaplan-Meier analysis was used to compare survival time among different groups. Median survival time was 83.8 ± 3.2. Cox regression showed that high vs low educational level (Hazard ratio (HR)= 0.35, 95% CI; 0.27-0.46), metastases to bone (HR = 3.22, 95% CI: 1.71-6.05), metastases to lung (HR= 2.314, 95% CI: 1.225-4.373), tumor size (≤ 2 cm vs ≥ 5 cm: HR = 1.4, 95% CI: 1.1-1.8) and number of involved nodes (1 vs > 10 HR = 5.21, 95%CI: 3.1-9.01) were significantly related to survival. The results showed the need to develop screening programs and standardized treatment regimens in a tax-funded health care system.

Modelling lecturer performance index of private university in Tulungagung by using survival analysis with multivariate adaptive regression spline

Science.gov (United States)

Hasyim, M.; Prastyo, D. D.

2018-03-01

Survival analysis performs relationship between independent variables and survival time as dependent variable. In fact, not all survival data can be recorded completely by any reasons. In such situation, the data is called censored data. Moreover, several model for survival analysis requires assumptions. One of the approaches in survival analysis is nonparametric that gives more relax assumption. In this research, the nonparametric approach that is employed is Multivariate Regression Adaptive Spline (MARS). This study is aimed to measure the performance of private university’s lecturer. The survival time in this study is duration needed by lecturer to obtain their professional certificate. The results show that research activities is a significant factor along with developing courses material, good publication in international or national journal, and activities in research collaboration.

Repair models of cell survival and corresponding computer program for survival curve fitting

International Nuclear Information System (INIS)

Shen Xun; Hu Yiwei

1992-01-01

Some basic concepts and formulations of two repair models of survival, the incomplete repair (IR) model and the lethal-potentially lethal (LPL) model, are introduced. An IBM-PC computer program for survival curve fitting with these models was developed and applied to fit the survivals of human melanoma cells HX118 irradiated at different dose rates. Comparison was made between the repair models and two non-repair models, the multitar get-single hit model and the linear-quadratic model, in the fitting and analysis of the survival-dose curves. It was shown that either IR model or LPL model can fit a set of survival curves of different dose rates with same parameters and provide information on the repair capacity of cells. These two mathematical models could be very useful in quantitative study on the radiosensitivity and repair capacity of cells

Survival rates and predictors of survival among colorectal cancer patients in a Malaysian tertiary hospital.

Science.gov (United States)

Magaji, Bello Arkilla; Moy, Foong Ming; Roslani, April Camilla; Law, Chee Wei

2017-05-18

Colorectal cancer is the third most commonly diagnosed malignancy and the fourth leading cause of cancer-related death globally. It is the second most common cancer among both males and females in Malaysia. The economic burden of colorectal cancer is likely to increase over time owing to its current trend and aging population. Cancer survival analysis is an essential indicator for early detection and improvement in cancer treatment. However, there was a scarcity of studies concerning survival of colorectal cancer patients as well as its predictors. Therefore, we aimed to determine the 1-, 3- and 5-year survival rates, compare survival rates among ethnic groups and determine the predictors of survival among colorectal cancer patients. This was an ambidirectional cohort study conducted at the University Malaya Medical Centre (UMMC) in Kuala Lumpur, Malaysia. All Malaysian citizens or permanent residents with histologically confirmed diagnosis of colorectal cancer seen at UMMC from 1 January 2001 to 31 December 2010 were included in the study. Demographic and clinical characteristics were extracted from the medical records. Patients were followed-up until death or censored at the end of the study (31st December 2010). Censored patients' vital status (whether alive or dead) were cross checked with the National Registration Department. Survival analyses at 1-, 3- and 5-year intervals were performed using the Kaplan-Meier method. Log-rank test was used to compare the survival rates, while Cox proportional hazard regression analysis was carried out to determine the predictors of 5-year colorectal cancer survival. Among 1212 patients, the median survival for colorectal, colon and rectal cancers were 42.0, 42.0 and 41.0 months respectively; while the 1-, 3-, and 5-year relative survival rates ranged from 73.8 to 76.0%, 52.1 to 53.7% and 40.4 to 45.4% respectively. The Chinese patients had the lowest 5-year survival compared to Malay and Indian patients. Based on the 814

Prognostic Factors for Survival in Patients with Gastric Cancer using a Random Survival Forest

Science.gov (United States)

Adham, Davoud; Abbasgholizadeh, Nategh; Abazari, Malek

2017-01-01

Background: Gastric cancer is the fifth most common cancer and the third top cause of cancer related death with about 1 million new cases and 700,000 deaths in 2012. The aim of this investigation was to identify important factors for outcome using a random survival forest (RSF) approach. Materials and Methods: Data were collected from 128 gastric cancer patients through a historical cohort study in Hamedan-Iran from 2007 to 2013. The event under consideration was death due to gastric cancer. The random survival forest model in R software was applied to determine the key factors affecting survival. Four split criteria were used to determine importance of the variables in the model including log-rank, conversation?? of events, log-rank score, and randomization. Efficiency of the model was confirmed in terms of Harrell’s concordance index. Results: The mean age of diagnosis was 63 ±12.57 and mean and median survival times were 15.2 (95%CI: 13.3, 17.0) and 12.3 (95%CI: 11.0, 13.4) months, respectively. The one-year, two-year, and three-year rates for survival were 51%, 13%, and 5%, respectively. Each RSF approach showed a slightly different ranking order. Very important covariates in nearly all the 4 RSF approaches were metastatic status, age at diagnosis and tumor size. The performance of each RSF approach was in the range of 0.29-0.32 and the best error rate was obtained by the log-rank splitting rule; second, third, and fourth ranks were log-rank score, conservation of events, and the random splitting rule, respectively. Conclusion: Low survival rate of gastric cancer patients is an indication of absence of a screening program for early diagnosis of the disease. Timely diagnosis in early phases increases survival and decreases mortality. Creative Commons Attribution License

Disparities in breast cancer tumor characteristics, treatment, time to treatment, and survival probability among African American and white women.

Science.gov (United States)

Foy, Kevin Chu; Fisher, James L; Lustberg, Maryam B; Gray, Darrell M; DeGraffinreid, Cecilia R; Paskett, Electra D

2018-01-01

African American (AA) women have a 42% higher breast cancer death rate compared to white women despite recent advancements in management of the disease. We examined racial differences in clinical and tumor characteristics, treatment and survival in patients diagnosed with breast cancer between 2005 and 2014 at a single institution, the James Cancer Hospital, and who were included in the Arthur G. James Cancer Hospital and Richard J. Solove Research Institute Cancer Registry in Columbus OH. Statistical analyses included likelihood ratio chi-square tests for differences in proportions, as well as univariate and multivariate Cox proportional hazards regressions to examine associations between race and overall and progression-free survival probabilities. AA women made up 10.2% (469 of 4593) the sample. Average time to onset of treatment after diagnosis was almost two times longer in AA women compared to white women (62.0 days vs 35.5 days, p  triple negative and late stage breast cancer, and were less likely to receive surgery, especially mastectomy and reconstruction following mastectomy. After adjustment for confounding factors (age, grade, and surgery), overall survival probability was significantly associated with race (HR = 1.33; 95% CI 1.03-1.72). These findings highlight the need for efforts focused on screening and receipt of prompt treatment among AA women diagnosed with breast cancer.

Survival time of bacteria on different plastics by application of ultraviolet rays and desinfectants

International Nuclear Information System (INIS)

Glueck, S.

1975-01-01

The survival times of four sorts of germs were studied (Staph. albus, Staph. aureus, E.coli and Clebsiella) on 28 different plastic surfaces under different ambient conditions, (darkness, daylight, UV-radiation) and after preceding disinfection of the surfaces. For these studies, a formaldehydecontaining, phenolic, and a surface-active preparation were used. No essential differences in the survival times of the 4 types of germs tested were found. Besides the chemical basic structure additional substances were found to play a substantial role for the autobactericides. The dark values which could help to obtain findings about auto-bactericides did not show significant correspondence within the groups of the plastics. Only for a few materials a safe auto-bactericide could be found (alkyd lake, phenol resin). In the case of some other substances (some preparations made of PVC, polystyrene, polyacetal) an effect on the germs could be seen which was, at least totally seen, unfavourable, if all test conditions (darkness, daylight, UV-radiation) are viewed as a total. As comparative values on glass had shown a lower lethal rate of the germs, a certain auto-bactericide is likely to exist in all plastics tested. A considerable antibacterial effect of daylight was found, even with low daylight quotients and clased windows. UV-rays also diminished the number of germs on the plastic surfaces considerably, even with only indirect irradiation. Delayed effects of desinfecting agents partially depend on the surface material. Thus the phenolic agent showed strong delayed effects on the acryl glas, polyethylene, phenol resin, polycarbonate, but less on PVC. Phormaldehyde showed a good long-term effect only on phenol resin. (orig.) [de

Assessment of Confounding in Studies of Delay and Survival

DEFF Research Database (Denmark)

Tørring, Marie Louise; Vedsted, Peter; Frydenberg, Morten

BACKGROUND: Whether longer time to diagnosis (diagnostic delay) in patients with cancer symptoms is directly and independently associated with poor prognosis cannot be determined in randomised controlled trials. Analysis of observational data is therefore necessary. Many previous studies of the i......BACKGROUND: Whether longer time to diagnosis (diagnostic delay) in patients with cancer symptoms is directly and independently associated with poor prognosis cannot be determined in randomised controlled trials. Analysis of observational data is therefore necessary. Many previous studies......) Clarify which factors are considered confounders or intermediate variables in the literature. 2) Assess how and to what extent these factors bias survival estimates. CONSIDERATIONS: As illustrated in Figure 1, symptoms of cancer may alert patients, GP's, and hospital doctors differently and influence both...... delay and survival time in different ways. We therefore assume that the impact of confounding factors depends on the type of delay studied (e.g., patient delay, GP delay, referral delay, or treatment delay). MATERIALS & METHODS: The project includes systematic review and methodological developments...

Network survivability performance (computer diskette)

Science.gov (United States)

1993-11-01

File characteristics: Data file; 1 file. Physical description: 1 computer diskette; 3 1/2 in.; high density; 2.0MB. System requirements: Mac; Word. This technical report has been developed to address the survivability of telecommunications networks including services. It responds to the need for a common understanding of, and assessment techniques for network survivability, availability, integrity, and reliability. It provides a basis for designing and operating telecommunication networks to user expectations for network survivability.

Development of a cell-based treatment for long-term neurotrophin expression and spiral ganglion neuron survival.

Science.gov (United States)

Zanin, M P; Hellström, M; Shepherd, R K; Harvey, A R; Gillespie, L N

2014-09-26

Spiral ganglion neurons (SGNs), the target cells of the cochlear implant, undergo gradual degeneration following loss of the sensory epithelium in deafness. The preservation of a viable population of SGNs in deafness can be achieved in animal models with exogenous application of neurotrophins such as brain-derived neurotrophic factor (BDNF) and neurotrophin-3. For translation into clinical application, a suitable delivery strategy that provides ongoing neurotrophic support and promotes long-term SGN survival is required. Cell-based neurotrophin treatment has the potential to meet the specific requirements for clinical application, and we have previously reported that Schwann cells genetically modified to express BDNF can support SGN survival in deafness for 4 weeks. This study aimed to investigate various parameters important for the development of a long-term cell-based neurotrophin treatment to support SGN survival. Specifically, we investigated different (i) cell types, (ii) gene transfer methods and (iii) neurotrophins, in order to determine which variables may provide long-term neurotrophin expression and which, therefore, may be the most effective for supporting long-term SGN survival in vivo. We found that fibroblasts that were nucleofected to express BDNF provided the most sustained neurotrophin expression, with ongoing BDNF expression for at least 30 weeks. In addition, the secreted neurotrophin was biologically active and elicited survival effects on SGNs in vitro. Nucleofected fibroblasts may therefore represent a method for safe, long-term delivery of neurotrophins to the deafened cochlea to support SGN survival in deafness. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Adjuvant Medications That Improve Survival after Locoregional Therapy.

Science.gov (United States)

Boas, F Edward; Ziv, Etay; Yarmohammadi, Hooman; Brown, Karen T; Erinjeri, Joseph P; Sofocleous, Constantinos T; Harding, James J; Solomon, Stephen B

2017-07-01

To determine if outpatient medications taken at the time of liver tumor embolization or ablation affect survival. A retrospective review was done of 2,032 liver tumor embolization, radioembolization, and ablation procedures performed in 1,092 patients from June 2009 to April 2016. Pathology, hepatocellular carcinoma (HCC) stage (American Joint Committee on Cancer), neuroendocrine tumor (NET) grade, initial locoregional therapy, overall survival after initial locoregional therapy, Child-Pugh score, Eastern Cooperative Oncology Group performance status, Charlson Comorbidity Index, and outpatient medications taken at the time of locoregional therapy were analyzed for each patient. Kaplan-Meier survival curves were calculated for patients taking 29 medications or medication classes (including prescription and nonprescription medications) for reasons unrelated to their primary cancer diagnosis. Kaplan-Meier curves were compared using the log-rank test. For patients with HCC initially treated with embolization (n = 304 patients), the following medications were associated with improved survival when taken at the time of embolization: beta-blockers (P = .0007), aspirin (P = .0008) and other nonsteroidal antiinflammatory drugs (P = .009), proton pump inhibitors (P = .004), and antivirals for hepatitis B or C (P = .01). For colorectal liver metastases initially treated with ablation (n = 172 patients), beta-blockers were associated with improved survival when taken at the time of ablation (P = .02). Aspirin and beta-blockers are associated with significantly improved survival when taken at the time of embolization for HCC. Aspirin was not associated with survival differences after locoregional therapy for NET or colorectal liver metastases, suggesting an HCC-specific effect. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

Sepsis and Shock Response Team: Impact of a Multidisciplinary Approach to Implementing Surviving Sepsis Campaign Guidelines and Surviving the Process.

Science.gov (United States)

Grek, Ami; Booth, Sandra; Festic, Emir; Maniaci, Michael; Shirazi, Ehsan; Thompson, Kristine; Starbuck, Angela; Mcree, Chad; Naessens, James M; Moreno Franco, Pablo

The Surviving Sepsis Campaign guidelines are designed to decrease mortality through consistent application of a 7-element bundle. This study evaluated the impact of improvement in bundle adherence using a time-series analysis of compliance with the bundle elements before and after interventions intended to improve the process, while also looking at hospital mortality. This article describes interventions used to improve bundle compliance and hospital mortality in patients admitted through the emergency department with sepsis, severe sepsis, or septic shock. Quality improvement methodology was used to develop high-impact interventions that led to dramatically improved adherence to the Surviving Sepsis Campaign guidelines bundle. Improved performance was associated with a significant decrease in the in-hospital mortality of severe sepsis patients presenting to the emergency department.

Mesenchymal stem cells increase skin graft survival time and up-regulate PD-L1 expression in splenocytes of mice.

Science.gov (United States)

Moravej, Ali; Geramizadeh, Bita; Azarpira, Negar; Zarnani, Amir-Hassan; Yaghobi, Ramin; Kalani, Mehdi; Khosravi, Maryam; Kouhpayeh, Amin; Karimi, Mohammad-Hossein

2017-02-01

Recently, mesenchymal stem cells (MSCs) have gained considerable interests as hopeful therapeutic cells in transplantation due to their immunoregulatory functions. But exact mechanisms underlying MSCs immunoregulatory function is not fully understood. Herein, in addition to investigate the ability of MSCs to prolong graft survival time, the effects of them on the expression of PD-L1 and IDO immunomodulatory molecules in splenocytes of skin graft recipient mice was clarified. To achieve this goal, full-thickness skins were transplanted from C57BL/6 to BALB/c mice. MSCs were isolated from bone marrow of BALB/c mice and injected to the recipient mice. Skin graft survival was monitored daily to determine graft rejection time. On days 2, 5 and 10 post skin transplantation, serum cytokine levels and expression of PD-L1 and IDO mRNA and protein in the splenocytes of recipient mice were evaluated. The results showed that administration of MSCs prolonged skin graft survival time from 11 to 14 days. On days 2 and 5 post transplantation, splenocytes PD-L1 expression and IL-10 serum level in MSCs treated mice were higher than those in the controls, while IL-2 and IFN-γ levels were lower. Rejection in MSCs treated mice was accompanied by an increase in IL-2 and IFN-γ, and decrease in PD-L1 expression and IL-10 level. No difference in the expression of IDO between MSCs treated mice and controls was observed. In conclusion, we found that one of the mechanisms underlying MSCs immunomodulatory function could be up-regulating PD-L1 expression. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Advanced Online Survival Analysis Tool for Predictive Modelling in Clinical Data Science.

Science.gov (United States)

Montes-Torres, Julio; Subirats, José Luis; Ribelles, Nuria; Urda, Daniel; Franco, Leonardo; Alba, Emilio; Jerez, José Manuel

2016-01-01

One of the prevailing applications of machine learning is the use of predictive modelling in clinical survival analysis. In this work, we present our view of the current situation of computer tools for survival analysis, stressing the need of transferring the latest results in the field of machine learning to biomedical researchers. We propose a web based software for survival analysis called OSA (Online Survival Analysis), which has been developed as an open access and user friendly option to obtain discrete time, predictive survival models at individual level using machine learning techniques, and to perform standard survival analysis. OSA employs an Artificial Neural Network (ANN) based method to produce the predictive survival models. Additionally, the software can easily generate survival and hazard curves with multiple options to personalise the plots, obtain contingency tables from the uploaded data to perform different tests, and fit a Cox regression model from a number of predictor variables. In the Materials and Methods section, we depict the general architecture of the application and introduce the mathematical background of each of the implemented methods. The study concludes with examples of use showing the results obtained with public datasets.

Estimation of age- and stage-specific Catalan breast cancer survival functions using US and Catalan survival data

Science.gov (United States)

2009-01-01

Background During the last part of the 1990s the chance of surviving breast cancer increased. Changes in survival functions reflect a mixture of effects. Both, the introduction of adjuvant treatments and early screening with mammography played a role in the decline in mortality. Evaluating the contribution of these interventions using mathematical models requires survival functions before and after their introduction. Furthermore, required survival functions may be different by age groups and are related to disease stage at diagnosis. Sometimes detailed information is not available, as was the case for the region of Catalonia (Spain). Then one may derive the functions using information from other geographical areas. This work presents the methodology used to estimate age- and stage-specific Catalan breast cancer survival functions from scarce Catalan survival data by adapting the age- and stage-specific US functions. Methods Cubic splines were used to smooth data and obtain continuous hazard rate functions. After, we fitted a Poisson model to derive hazard ratios. The model included time as a covariate. Then the hazard ratios were applied to US survival functions detailed by age and stage to obtain Catalan estimations. Results We started estimating the hazard ratios for Catalonia versus the USA before and after the introduction of screening. The hazard ratios were then multiplied by the age- and stage-specific breast cancer hazard rates from the USA to obtain the Catalan hazard rates. We also compared breast cancer survival in Catalonia and the USA in two time periods, before cancer control interventions (USA 1975–79, Catalonia 1980–89) and after (USA and Catalonia 1990–2001). Survival in Catalonia in the 1980–89 period was worse than in the USA during 1975–79, but the differences disappeared in 1990–2001. Conclusion Our results suggest that access to better treatments and quality of care contributed to large improvements in survival in Catalonia. On

A Validated Prediction Model for Overall Survival From Stage III Non-Small Cell Lung Cancer: Toward Survival Prediction for Individual Patients

Energy Technology Data Exchange (ETDEWEB)

Oberije, Cary, E-mail: cary.oberije@maastro.nl [Radiation Oncology, Research Institute GROW of Oncology, Maastricht University Medical Center, Maastricht (Netherlands); De Ruysscher, Dirk [Radiation Oncology, Research Institute GROW of Oncology, Maastricht University Medical Center, Maastricht (Netherlands); Universitaire Ziekenhuizen Leuven, KU Leuven (Belgium); Houben, Ruud [Radiation Oncology, Research Institute GROW of Oncology, Maastricht University Medical Center, Maastricht (Netherlands); Heuvel, Michel van de; Uyterlinde, Wilma [Department of Thoracic Oncology, Netherlands Cancer Institute, Amsterdam (Netherlands); Deasy, Joseph O. [Memorial Sloan Kettering Cancer Center, New York (United States); Belderbos, Jose [Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam (Netherlands); Dingemans, Anne-Marie C. [Department of Pulmonology, University Hospital Maastricht, Research Institute GROW of Oncology, Maastricht (Netherlands); Rimner, Andreas; Din, Shaun [Memorial Sloan Kettering Cancer Center, New York (United States); Lambin, Philippe [Radiation Oncology, Research Institute GROW of Oncology, Maastricht University Medical Center, Maastricht (Netherlands)

2015-07-15

Purpose: Although patients with stage III non-small cell lung cancer (NSCLC) are homogeneous according to the TNM staging system, they form a heterogeneous group, which is reflected in the survival outcome. The increasing amount of information for an individual patient and the growing number of treatment options facilitate personalized treatment, but they also complicate treatment decision making. Decision support systems (DSS), which provide individualized prognostic information, can overcome this but are currently lacking. A DSS for stage III NSCLC requires the development and integration of multiple models. The current study takes the first step in this process by developing and validating a model that can provide physicians with a survival probability for an individual NSCLC patient. Methods and Materials: Data from 548 patients with stage III NSCLC were available to enable the development of a prediction model, using stratified Cox regression. Variables were selected by using a bootstrap procedure. Performance of the model was expressed as the c statistic, assessed internally and on 2 external data sets (n=174 and n=130). Results: The final multivariate model, stratified for treatment, consisted of age, gender, World Health Organization performance status, overall treatment time, equivalent radiation dose, number of positive lymph node stations, and gross tumor volume. The bootstrapped c statistic was 0.62. The model could identify risk groups in external data sets. Nomograms were constructed to predict an individual patient's survival probability ( (www.predictcancer.org)). The data set can be downloaded at (https://www.cancerdata.org/10.1016/j.ijrobp.2015.02.048). Conclusions: The prediction model for overall survival of patients with stage III NSCLC highlights the importance of combining patient, clinical, and treatment variables. Nomograms were developed and validated. This tool could be used as a first building block for a decision support system.

Foreign Ownership and Long-term Survival

DEFF Research Database (Denmark)

Kronborg, Dorte; Thomsen, Steen

2006-01-01

probability. On average exit risk for domestic companies is 2.3 times higher than for foreign companies. First movers like Siemens, Philips, Kodak, Ford, GM or Goodyear have been active in the country for almost a century. Relative foreign survival increases with company age. However, the foreign survival...

Effects of Temperatures on Immature Development and Survival of the Invasive Stink Bug (Hemiptera: Pentatomidae).

Science.gov (United States)

Reed, Darcy A; Ganjisaffar, Fatemeh; Palumbo, John C; Perring, Thomas M

2017-12-05

Bagrada hilaris (Burmeister) (Hemiptera: Pentatomidae) is a non-native stink bug that feeds primarily on cole crops and wild mustards. Its invasion into desert agriculture in California and Arizona presents a conundrum between rapid pest development at warm temperatures and severe damage to cool season crops. In this study, the development and survival of B. hilaris were determined at nine constant temperatures (ranging from 20-42°C) when reared on organically grown broccoli florets. Egg hatching was greatly delayed at 20°C, and first instar nymphs did not survive at this temperature. No eggs hatched at 42°C. The highest survival rates (70.0-86.7%) of B. hilaris were observed at temperatures ranging from 24 to 35°C. The total developmental rate of B. hilaris from egg to adult increased from 0.027 to 0.066/d from 24 to 35°C, and then slightly dropped to 0.064/d at 39°C. Based on the linear model, B. hilaris requires 285.4 degree-days to complete its development. The Briere 1 model predicted the lower and upper temperature thresholds as 16.7 and 42.7°C, respectively. The optimal temperature for development (TOpt) was estimated as 36°C. According to the results, B. hilaris is well adapted to warm conditions, and temperatures of 33-39°C are well suited for B. hilaris development. Information from this study helps explain the rapid range expansion of B. hilaris across the southern United States and will be instrumental in predicting future expansion across the rest of the country and in other parts of the world. The relationship between thermal thresholds and invasion dynamics of this pest are discussed. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Hospital-based colorectal cancer survival trend of different tumor locations from 1960s to 2000s.

Directory of Open Access Journals (Sweden)

Yu-Jing Fang

Full Text Available BACKGROUND: Our aim is to explore the trend of association between the survival rates of colorectal cancer (CRC and the different clinical characteristics in patients registered from 1960s to 2000s. We hypothesized that the survival rate of CRC increases over time and varies according to anatomic subsites. METHODS: Information from a total of 4558 stage T(1-4N(1-2M0 CRC patients registered from 1960s to 2008 were analyzed. The association of CRC overall survival with age, gender, tumor locations, time, histopathology types, pathology grades, no. of examined lymph nodes, the T stage, and the N stage was analyzed. The assessment of the influence of prognostic factors on patient survival was performed using Cox's proportional hazard regression models. RESULTS: From 1960 to 2008, the studied CRC patients included 2625 (57.6% and 1933 (42.4% males and females, respectively. These included 1896 (41.6% colon cancers, and 2662 (58.4% rectum cancers. The 5-year survival rate was 49%, 58%, 58%, 70%, and 77% for the time duration of 1960s, 1970s, 1980s, 1990s and 2000s, respectively. An increased 5-year survival rate was observed in the colon cancer and rectum cancer patients. Patients older than 60 years of age were more likely to develop colonic cancer (sigmoid than rectum cancer (49.2% vs. 39.9%. The Cox regression model showed that only rectum cancer survival was related to time duration. CONCLUSION: The overall survival and 5-year survival rates showed an increase from the 1960s to 2000s. There is a trend of rightward shift of tumor location in CRC patients.

Survival Analysis

CERN Document Server

Miller, Rupert G

2011-01-01

A concise summary of the statistical methods used in the analysis of survival data with censoring. Emphasizes recently developed nonparametric techniques. Outlines methods in detail and illustrates them with actual data. Discusses the theory behind each method. Includes numerous worked problems and numerical exercises.

Nonparametric Bayesian inference for mean residual life functions in survival analysis.

Science.gov (United States)

Poynor, Valerie; Kottas, Athanasios

2018-01-19

Modeling and inference for survival analysis problems typically revolves around different functions related to the survival distribution. Here, we focus on the mean residual life (MRL) function, which provides the expected remaining lifetime given that a subject has survived (i.e. is event-free) up to a particular time. This function is of direct interest in reliability, medical, and actuarial fields. In addition to its practical interpretation, the MRL function characterizes the survival distribution. We develop general Bayesian nonparametric inference for MRL functions built from a Dirichlet process mixture model for the associated survival distribution. The resulting model for the MRL function admits a representation as a mixture of the kernel MRL functions with time-dependent mixture weights. This model structure allows for a wide range of shapes for the MRL function. Particular emphasis is placed on the selection of the mixture kernel, taken to be a gamma distribution, to obtain desirable properties for the MRL function arising from the mixture model. The inference method is illustrated with a data set of two experimental groups and a data set involving right censoring. The supplementary material available at Biostatistics online provides further results on empirical performance of the model, using simulated data examples. © The Author 2018. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Estimating the average treatment effect on survival based on observational data and using partly conditional modeling.

Science.gov (United States)

Gong, Qi; Schaubel, Douglas E

2017-03-01

Treatments are frequently evaluated in terms of their effect on patient survival. In settings where randomization of treatment is not feasible, observational data are employed, necessitating correction for covariate imbalances. Treatments are usually compared using a hazard ratio. Most existing methods which quantify the treatment effect through the survival function are applicable to treatments assigned at time 0. In the data structure of our interest, subjects typically begin follow-up untreated; time-until-treatment, and the pretreatment death hazard are both heavily influenced by longitudinal covariates; and subjects may experience periods of treatment ineligibility. We propose semiparametric methods for estimating the average difference in restricted mean survival time attributable to a time-dependent treatment, the average effect of treatment among the treated, under current treatment assignment patterns. The pre- and posttreatment models are partly conditional, in that they use the covariate history up to the time of treatment. The pre-treatment model is estimated through recently developed landmark analysis methods. For each treated patient, fitted pre- and posttreatment survival curves are projected out, then averaged in a manner which accounts for the censoring of treatment times. Asymptotic properties are derived and evaluated through simulation. The proposed methods are applied to liver transplant data in order to estimate the effect of liver transplantation on survival among transplant recipients under current practice patterns. © 2016, The International Biometric Society.

Male microchimerism and survival among women

DEFF Research Database (Denmark)

Kamper-Jørgensen, Mads; Hjalgrim, Henrik; Andersen, Anne-Marie Nybo

2014-01-01

During pregnancy, woman and fetus exchange small quantities of cells, and their persistence at later times is termed microchimerism. Microchimerism is known to substantially impact on women's later health. This study examined the survival of women according to male microchimerism status.......During pregnancy, woman and fetus exchange small quantities of cells, and their persistence at later times is termed microchimerism. Microchimerism is known to substantially impact on women's later health. This study examined the survival of women according to male microchimerism status....

Causal Mediation Analysis of Survival Outcome with Multiple Mediators.

Science.gov (United States)

Huang, Yen-Tsung; Yang, Hwai-I

2017-05-01

Mediation analyses have been a popular approach to investigate the effect of an exposure on an outcome through a mediator. Mediation models with multiple mediators have been proposed for continuous and dichotomous outcomes. However, development of multimediator models for survival outcomes is still limited. We present methods for multimediator analyses using three survival models: Aalen additive hazard models, Cox proportional hazard models, and semiparametric probit models. Effects through mediators can be characterized by path-specific effects, for which definitions and identifiability assumptions are provided. We derive closed-form expressions for path-specific effects for the three models, which are intuitively interpreted using a causal diagram. Mediation analyses using Cox models under the rare-outcome assumption and Aalen additive hazard models consider effects on log hazard ratio and hazard difference, respectively; analyses using semiparametric probit models consider effects on difference in transformed survival time and survival probability. The three models were applied to a hepatitis study where we investigated effects of hepatitis C on liver cancer incidence mediated through baseline and/or follow-up hepatitis B viral load. The three methods show consistent results on respective effect scales, which suggest an adverse estimated effect of hepatitis C on liver cancer not mediated through hepatitis B, and a protective estimated effect mediated through the baseline (and possibly follow-up) of hepatitis B viral load. Causal mediation analyses of survival outcome with multiple mediators are developed for additive hazard and proportional hazard and probit models with utility demonstrated in a hepatitis study.

Survivability Assessment: Modeling A Recovery Process

OpenAIRE

Paputungan, Irving Vitra; Abdullah, Azween

2009-01-01

Survivability is the ability of a system to continue operating, in a timely manner, in the presence ofattacks, failures, or accidents. Recovery in survivability is a process of a system to heal or recover from damageas early as possible to fulfill its mission as condition permit. In this paper, we show a preliminary recoverymodel to enhance the system survivability. The model focuses on how we preserve the system and resumes itscritical service under attacks as soon as possible.Keywords: surv...

Survival probability of a local excitation in a non-Markovian environment: Survival collapse, Zeno and anti-Zeno effects

International Nuclear Information System (INIS)

Rufeil-Fiori, E.; Pastawski, H.M.

2009-01-01

The decay dynamics of a local excitation interacting with a non-Markovian environment, modeled by a semi-infinite tight-binding chain, is exactly evaluated. We identify distinctive regimes for the dynamics. Sequentially: (i) early quadratic decay of the initial-state survival probability, up to a spreading time t S , (ii) exponential decay described by a self-consistent Fermi Golden Rule, and (iii) asymptotic behavior governed by quantum diffusion through the return processes, leading to an inverse power law decay. At this last cross-over time t R a survival collapse becomes possible. This could reduce the survival probability by several orders of magnitude. The cross-over times t S and t R allow to assess the range of applicability of the Fermi Golden Rule and give the conditions for the observation of the Zeno and anti-Zeno effect.

The influence of social structure on brood survival and development in a socially polymorphic ant: insights from a cross-fostering experiment.

Science.gov (United States)

Purcell, Jessica; Chapuisat, M

2012-11-01

Animal societies vary in the number of breeders per group, which affects many socially and ecologically relevant traits. In several social insect species, including our study species Formica selysi, the presence of either one or multiple reproducing females per colony is generally associated with differences in a suite of traits such as the body size of individuals. However, the proximate mechanisms and ontogenetic processes generating such differences between social structures are poorly known. Here, we cross-fostered eggs originating from single-queen (= monogynous) or multiple-queen (= polygynous) colonies into experimental groups of workers from each social structure to investigate whether differences in offspring survival, development time and body size are shaped by the genotype and/or prefoster maternal effects present in the eggs, or by the social origin of the rearing workers. Eggs produced by polygynous queens were more likely to survive to adulthood than eggs from monogynous queens, regardless of the social origin of the rearing workers. However, brood from monogynous queens grew faster than brood from polygynous queens. The social origin of the rearing workers influenced the probability of brood survival, with workers from monogynous colonies rearing more brood to adulthood than workers from polygynous colonies. The social origin of eggs or rearing workers had no significant effect on the head size of the resulting workers in our standardized laboratory conditions. Overall, the social backgrounds of the parents and of the rearing workers appear to shape distinct survival and developmental traits of ant brood. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

Survival rate and expression of Heat-shock protein 70 and Frost genes after temperature stress in Drosophila melanogaster lines that are selected for recovery time from temperature coma.

Science.gov (United States)

Udaka, Hiroko; Ueda, Chiaki; Goto, Shin G

2010-12-01

In this study, we investigated the physiological mechanisms underlying temperature tolerance using Drosophila melanogaster lines with rapid, intermediate, or slow recovery from heat or chill coma that were established by artificial selection or by free recombination without selection. Specifically, we focused on the relationships among their recovery from heat or chill coma, survival after severe heat or cold, and survival enhanced by rapid cold hardening (RCH) or heat hardening. The recovery time from heat coma was not related to the survival rate after severe heat. The line with rapid recovery from chill coma showed a higher survival rate after severe cold exposure, and therefore the same mechanisms are likely to underlie these phenotypes. The recovery time from chill coma and survival rate after severe cold were unrelated to RCH-enhanced survival. We also examined the expression of two genes, Heat-shock protein 70 (Hsp70) and Frost, in these lines to understand the contribution of these stress-inducible genes to intraspecific variation in recovery from temperature coma. The line showing rapid recovery from heat coma did not exhibit higher expression of Hsp70 and Frost. In addition, Hsp70 and Frost transcription levels were not correlated with the recovery time from chill coma. Thus, Hsp70 and Frost transcriptional regulation was not involved in the intraspecific variation in recovery from temperature coma. Copyright © 2010 Elsevier Ltd. All rights reserved.

Modelling survival: exposure pattern, species sensitivity and uncertainty.

Science.gov (United States)

Ashauer, Roman; Albert, Carlo; Augustine, Starrlight; Cedergreen, Nina; Charles, Sandrine; Ducrot, Virginie; Focks, Andreas; Gabsi, Faten; Gergs, André; Goussen, Benoit; Jager, Tjalling; Kramer, Nynke I; Nyman, Anna-Maija; Poulsen, Veronique; Reichenberger, Stefan; Schäfer, Ralf B; Van den Brink, Paul J; Veltman, Karin; Vogel, Sören; Zimmer, Elke I; Preuss, Thomas G

2016-07-06

The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species. Firstly, using synthetic data, we identified experimental data requirements which allow for the estimation of all parameters of the GUTS proper model. Secondly, we assessed how well GUTS, calibrated with short-term survival data of Gammarus pulex exposed to four pesticides, can forecast effects of longer-term pulsed exposures. Thirdly, we tested the ability of GUTS to estimate 14-day median effect concentrations of malathion for a range of species and use these estimates to build species sensitivity distributions for different exposure patterns. We find that GUTS adequately predicts survival across exposure patterns that vary over time. When toxicity is assessed for time-variable concentrations species may differ in their responses depending on the exposure profile. This can result in different species sensitivity rankings and safe levels. The interplay of exposure pattern and species sensitivity deserves systematic investigation in order to better understand how organisms respond to stress, including humans.

Survival of Salmonella enterica in poultry feed is strain dependent.

Science.gov (United States)

Andino, Ana; Pendleton, Sean; Zhang, Nan; Chen, Wei; Critzer, Faith; Hanning, Irene

2014-02-01

Feed components have low water activity, making bacterial survival difficult. The mechanisms of Salmonella survival in feed and subsequent colonization of poultry are unknown. The purpose of this research was to compare the ability of Salmonella serovars and strains to survive in broiler feed and to evaluate molecular mechanisms associated with survival and colonization by measuring the expression of genes associated with colonization (hilA, invA) and survival via fatty acid synthesis (cfa, fabA, fabB, fabD). Feed was inoculated with 1 of 15 strains of Salmonella enterica consisting of 11 serovars (Typhimurium, Enteriditis, Kentucky, Seftenburg, Heidelberg, Mbandanka, Newport, Bairely, Javiana, Montevideo, and Infantis). To inoculate feed, cultures were suspended in PBS and survival was evaluated by plating samples onto XLT4 agar plates at specific time points (0 h, 4 h, 8 h, 24 h, 4 d, and 7 d). To evaluate gene expression, RNA was extracted from the samples at the specific time points (0, 4, 8, and 24 h) and gene expression measured with real-time PCR. The largest reduction in Salmonella occurred at the first and third sampling time points (4 h and 4 d) with the average reductions being 1.9 and 1.6 log cfu per g, respectively. For the remaining time points (8 h, 24 h, and 7 d), the average reduction was less than 1 log cfu per g (0.6, 0.4, and 0.6, respectively). Most strains upregulated cfa (cyclopropane fatty acid synthesis) within 8 h, which would modify the fluidity of the cell wall to aid in survival. There was a weak negative correlation between survival and virulence gene expression indicating downregulation to focus energy on other gene expression efforts such as survival-related genes. These data indicate the ability of strains to survive over time in poultry feed was strain dependent and that upregulation of cyclopropane fatty acid synthesis and downregulation of virulence genes were associated with a response to desiccation stress.

Protocol of the Definition for the Assessment of Time-to-event Endpoints in CANcer trials (DATECAN) project: formal consensus method for the development of guidelines for standardised time-to-event endpoints' definitions in cancer clinical trials.

Science.gov (United States)

Bellera, Carine A; Pulido, Marina; Gourgou, Sophie; Collette, Laurence; Doussau, Adélaïde; Kramar, Andrew; Dabakuyo, Tienhan Sandrine; Ouali, Monia; Auperin, Anne; Filleron, Thomas; Fortpied, Catherine; Le Tourneau, Christophe; Paoletti, Xavier; Mauer, Murielle; Mathoulin-Pélissier, Simone; Bonnetain, Franck

2013-03-01

In randomised phase III cancer clinical trials, the most objectively defined and only validated time-to-event endpoint is overall survival (OS). The appearance of new types of treatments and the multiplication of lines of treatment have resulted in the use of surrogate endpoints for overall survival such as progression-free survival (PFS), or time-to-treatment failure. Their development is strongly influenced by the necessity of reducing clinical trial duration, cost and number of patients. However, while these endpoints are frequently used, they are often poorly defined and definitions can differ between trials which may limit their use as primary endpoints. Moreover, this variability of definitions can impact on the trial's results by affecting estimation of treatments' effects. The aim of the Definition for the Assessment of Time-to-event Endpoints in CANcer trials (DATECAN) project is to provide recommendations for standardised definitions of time-to-event endpoints in randomised cancer clinical trials. We will use a formal consensus methodology based on experts' opinions which will be obtained in a systematic manner. Definitions will be independently developed for several cancer sites, including pancreatic, breast, head and neck and colon cancer, as well as sarcomas and gastrointestinal stromal tumours (GISTs). The DATECAN project should lead to the elaboration of recommendations that can then be used as guidelines by researchers participating in clinical trials. This process should lead to a standardisation of the definitions of commonly used time-to-event endpoints, enabling appropriate comparisons of future trials' results. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of smoking on survival of patients with hepatocellular carcinoma.

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Kolly, Philippe; Knöpfli, Marina; Dufour, Jean-François

2017-11-01

Lifestyle factors such as smoking, obesity and physical activity have gained interest in the field of hepatocellular carcinoma. These factors play a significant role in the development of hepatocellular carcinoma. Several studies revealed the impact of tobacco consumption on the development of hepatocellular carcinoma and its synergistic effects with viral etiologies (hepatitis B and C). The effects of smoking on survival in patients with a diagnosed hepatocellular carcinoma have not yet been investigated in a Western cohort where hepatitis C infection is a major risk factor. Using data from a prospective cohort of patients with hepatocellular carcinoma who were followed at the University Hospital of Bern, Switzerland, survival was compared by Kaplan-Meier analysis in smokers and nonsmokers, and multivariate Cox regression was applied to control for confounding variables. Of 238 eligible hepatocellular carcinoma patients, 64 were smokers at the time of inclusion and 174 were nonsmokers. Smokers had a significant worse overall survival than nonsmokers (hazard ratio 1.77, 95% confidence interval: 1.22-2.58, P=.003). Analysis of patients according to their underlying liver disease, revealed that smoking, and not nonsmoking, affected survival of hepatitis B virus and C virus-infected patients only. In this subgroup, smoking was an independent predictor for survival (hazard ratio 2.99, 95% confidence interval: 1.7-5.23, Phepatocellular carcinoma. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Breast cancer data analysis for survivability studies and prediction.

Science.gov (United States)

Shukla, Nagesh; Hagenbuchner, Markus; Win, Khin Than; Yang, Jack

2018-03-01

Breast cancer is the most common cancer affecting females worldwide. Breast cancer survivability prediction is challenging and a complex research task. Existing approaches engage statistical methods or supervised machine learning to assess/predict the survival prospects of patients. The main objectives of this paper is to develop a robust data analytical model which can assist in (i) a better understanding of breast cancer survivability in presence of missing data, (ii) providing better insights into factors associated with patient survivability, and (iii) establishing cohorts of patients that share similar properties. Unsupervised data mining methods viz. the self-organising map (SOM) and density-based spatial clustering of applications with noise (DBSCAN) is used to create patient cohort clusters. These clusters, with associated patterns, were used to train multilayer perceptron (MLP) model for improved patient survivability analysis. A large dataset available from SEER program is used in this study to identify patterns associated with the survivability of breast cancer patients. Information gain was computed for the purpose of variable selection. All of these methods are data-driven and require little (if any) input from users or experts. SOM consolidated patients into cohorts of patients with similar properties. From this, DBSCAN identified and extracted nine cohorts (clusters). It is found that patients in each of the nine clusters have different survivability time. The separation of patients into clusters improved the overall survival prediction accuracy based on MLP and revealed intricate conditions that affect the accuracy of a prediction. A new, entirely data driven approach based on unsupervised learning methods improves understanding and helps identify patterns associated with the survivability of patient. The results of the analysis can be used to segment the historical patient data into clusters or subsets, which share common variable values and

Developing and Validating a Survival Prediction Model for NSCLC Patients Through Distributed Learning Across 3 Countries.

Science.gov (United States)

Jochems, Arthur; Deist, Timo M; El Naqa, Issam; Kessler, Marc; Mayo, Chuck; Reeves, Jackson; Jolly, Shruti; Matuszak, Martha; Ten Haken, Randall; van Soest, Johan; Oberije, Cary; Faivre-Finn, Corinne; Price, Gareth; de Ruysscher, Dirk; Lambin, Philippe; Dekker, Andre

2017-10-01

Tools for survival prediction for non-small cell lung cancer (NSCLC) patients treated with chemoradiation or radiation therapy are of limited quality. In this work, we developed a predictive model of survival at 2 years. The model is based on a large volume of historical patient data and serves as a proof of concept to demonstrate the distributed learning approach. Clinical data from 698 lung cancer patients, treated with curative intent with chemoradiation or radiation therapy alone, were collected and stored at 2 different cancer institutes (559 patients at Maastro clinic (Netherlands) and 139 at Michigan university [United States]). The model was further validated on 196 patients originating from The Christie (United Kingdon). A Bayesian network model was adapted for distributed learning (the animation can be viewed at https://www.youtube.com/watch?v=ZDJFOxpwqEA). Two-year posttreatment survival was chosen as the endpoint. The Maastro clinic cohort data are publicly available at https://www.cancerdata.org/publication/developing-and-validating-survival-prediction-model-nsclc-patients-through-distributed, and the developed models can be found at www.predictcancer.org. Variables included in the final model were T and N category, age, performance status, and total tumor dose. The model has an area under the curve (AUC) of 0.66 on the external validation set and an AUC of 0.62 on a 5-fold cross validation. A model based on the T and N category performed with an AUC of 0.47 on the validation set, significantly worse than our model (PLearning the model in a centralized or distributed fashion yields a minor difference on the probabilities of the conditional probability tables (0.6%); the discriminative performance of the models on the validation set is similar (P=.26). Distributed learning from federated databases allows learning of predictive models on data originating from multiple institutions while avoiding many of the data-sharing barriers. We believe that

Survival rates of birds of tropical and temperate forests: will the dogma survive?

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Karr, J.R.; Nichols, J.D.; Klimkiewicz, M.K.; Brawn, J.D.

1990-01-01

Survival rates of tropical forest birds are widely assumed to be high relative to the survival rates of temperate forest birds. Much life-history theory is based on this assumption despite the lack of empirical data to support it. We provide the first detailed comparison of survival rates of tropical and temperate forest birds based on extensive data bases and modern capture-recapture models. We find no support for the conventional wisdom. Because clutch size is only one component of reproductive rate, the frequently assumed, simple association between clutch size and adult survival rates should not necessarily be expected. Our results emphasize the need to consider components of fecundity in addition to clutch size when comparing the life histories of tropical and temperate birds and suggest similar considerations in the development of vertebrate life-history theory.

Human umbilical-cord-blood mononucleated cells enhance the survival of lethally irradiated mice. Dosage and the window of time

International Nuclear Information System (INIS)

Kovalenko, Olga A.; Ende, Norman; Azzam, Edouard I.

2013-01-01

The purpose of this study was to evaluate the window of time and dose of human umbilical-cord-blood (HUCB) mononucleated cells necessary for successful treatment of radiation injury in mice. Female A/J mice (27-30 weeks old) were exposed to an absorbed dose of 9-10 Gy of 137 Cs γ-rays delivered acutely to the whole body. They were treated either with 1 × 10 8 or 2 × 10 8 HUCB mononucleated cells at 24-52 h after the irradiation. The antibiotic Levaquin was applied 4 h postirradiation. The increased dose of cord-blood cells resulted in enhanced survival. The enhancement of survival in animals that received 2 × 10 8 HUCB mononucleated cells relative to irradiated but untreated animals was highly significant (P < 0.01). Compared with earlier studies, the increased dose of HUCB mononucleated cells, coupled with early use of an antibiotic, extended the window of time for effective treatment of severe radiation injury from 4 to 24-52 h after exposure. (author)

Effect of Nanoparticles on the Survival and Development of Vitrified Porcine GV Oocytes.

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Li, W J; Zhou, X L; Liu, B L; Dai, J J; Song, P; Teng, Y

BACKGROUND: Some mammalian oocytes have been successfully cryopreserved by vitrification. However, the survival and developmental rate of vitrified oocytes is still low. The incorporation of nanoparticles into cryoprotectant (CPA) may improve the efficiency of vitrification by changing the properties of solutions. The toxicity of different concentrations of hydroxy apatite (HA), silica dioxide (SO 2 ), aluminum oxide (Al 2 O 3 ) and titanium dioxide (TiO 2 ) nanoparticles (20 nm in diameter) to oocytes was tested and the toxicity threshold value of each nanoparticle was determined. Porcine GV oocytes were vitrified in optimized nano-CPA, and effects of diameter and concentration of nanoparticles on the survival rate and developmental rate of porcine GV oocytes were compared. HA nanoparticles have demonstrated the least toxicity among four nanoparticles and the developmental rate of GV-stage porcine oocytes was 100% when its concentration was lower than 0.5%. By adding 0.1% HA into VS, the developmental rate of GV-stage porcine oocytes (22%) was significantly higher than other groups. The effect of vitrification in nano-CPA on oocytes was related to the concentration of HA nanoparticles rather than their size. By adding 0.05% HA nanoparticles (60nm in diameter), the developmental rate increased dramatically from 14.7% to 30.4%. Nano-cryopreservation offers a new way to improve the effect of survival and development of oocytes, but the limitation of this technology shall not be ignored.

Effects of rearing temperature and density on growth, survival and development of sea cucumber larvae, Apostichopus japonicus (Selenka)

Science.gov (United States)

Liu, Guangbin; Yang, Hongsheng; Liu, Shilin

2010-07-01

In laboratory conditions, effects of rearing temperature and stocking density were examined on hatching of fertilized egg and growth of auricularia larvae of Apostichopus japonicus respectively. Data series like larval length and density, metamorphic time, and survival rate of the larvae were recorded. Statistics showed that for A. japonicus, survival rate (from fertilized egg to late auricularia) decreased significantly with the increasing rearing temperature ( P26°C). Hatching rate was significantly different between 0.2-5 ind./ml groups and 20-50 ind./ml groups. Rearing larvae at the higher density had the smaller maximal-length, whereas needed longer time to complete metamorphosis. This study suggested that 21°C and 0.4 ind./ml can be used as the most suitable rearing temperature and stocking density for large -scale artificial breeding of A. japonicus’s larvae.

Milkweed Matters: Monarch Butterfly (Lepidoptera: Nymphalidae) Survival and Development on Nine Midwestern Milkweed Species.

Science.gov (United States)

Pocius, V M; Debinski, D M; Pleasants, J M; Bidne, K G; Hellmich, R L; Brower, L P

2017-10-01

The population of monarch butterflies east of the Rocky Mountains has experienced a significant decline over the past 20 yr. In order to increase monarch numbers in the breeding range, habitat restoration that includes planting milkweed plants is essential. Milkweeds in the genus Asclepias and Cynanchum are the only host plants for larval monarch butterflies in North America, but larval performance and survival across nine milkweeds native to the Midwest is not well documented. We examined development and survival of monarchs from first-instar larval stages to adulthood on nine milkweed species native to Iowa. The milkweeds included Asclepias exaltata (poke milkweed) (Gentianales: Apocynaceae), Asclepias hirtella (tall green milkweed) (Gentianales: Apocynaceae), Asclepias incarnata (swamp milkweed) (Gentianales: Apocynaceae), Asclepias speciosa (showy milkweed) (Gentianales: Apocynaceae), Asclepias sullivantii (prairie milkweed) (Gentianales: Apocynaceae), Asclepias syriaca (common milkweed) (Gentianales: Apocynaceae), Asclepias tuberosa (butterfly milkweed) (Gentianales: Apocynaceae), Asclepias verticillata (whorled milkweed) (Gentianales: Apocynaceae), and Cynanchum laeve (honey vine milkweed) (Gentianales: Apocynaceae). In greenhouse experiments, fewer larvae that fed on Asclepias hirtella and Asclepias sullivantii reached adulthood compared with larvae that fed on the other milkweed species. Monarch pupal width and adult dry mass differed among milkweeds, but larval duration (days), pupal duration (days), pupal mass, pupal length, and adult wet mass were not significantly different. Both the absolute and relative adult lipids were different among milkweed treatments; these differences are not fully explained by differences in adult dry mass. Monarch butterflies can survive on all nine milkweed species, but the expected survival probability varied from 30 to 75% among the nine milkweed species. © The Author 2017. Published by Oxford University Press on behalf

Network ties and survival

DEFF Research Database (Denmark)

Acheampong, George; Narteh, Bedman; Rand, John

2017-01-01

Poultry farming has been touted as one of the major ways by which poverty can be reduced in low-income economies like Ghana. Yet, anecdotally there is a high failure rate among these poultry farms. This current study seeks to understand the relationship between network ties and survival chances...... of small commercial poultry farms (SCPFs). We utilize data from a 2-year network survey of SCPFs in rural Ghana. The survival of these poultry farms are modelled using a lagged probit model of farms that persisted from 2014 into 2015. We find that network ties are important to the survival chances...... but this probability reduces as the number of industry ties increases but moderation with dynamic capability of the firm reverses this trend. Our findings show that not all network ties aid survival and therefore small commercial poultry farmers need to be circumspect in the network ties they cultivate and develop....

Polygenic Score × Intervention Moderation: an Application of Discrete-Time Survival Analysis to Model the Timing of First Marijuana Use Among Urban Youth.

Science.gov (United States)

Musci, Rashelle J; Fairman, Brian; Masyn, Katherine E; Uhl, George; Maher, Brion; Sisto, Danielle Y; Kellam, Sheppard G; Ialongo, Nicholas S

2018-01-01

The present study examines the interaction between a polygenic score and an elementary school-based universal preventive intervention trial and its effects on a discrete-time survival analysis of time to first smoking marijuana. Research has suggested that initiation of substances is both genetically and environmentally driven (Rhee et al., Archives of general psychiatry 60:1256-1264, 2003; Verweij et al., Addiction 105:417-430, 2010). A previous work has found a significant interaction between the polygenic score and the same elementary school-based intervention with tobacco smoking (Musci et al., in press). The polygenic score reflects the contribution of multiple genes and has been shown in prior research to be predictive of smoking cessation, tobacco use, and marijuana use (Uhl et al., Molecular Psychiatry 19:50-54, 2014). Using data from a longitudinal preventive intervention study (N = 678), we examined age of first marijuana use from sixth grade to age 18. Genetic data were collected during emerging adulthood and were genotyped using the Affymetrix 6.0 microarray (N = 545). The polygenic score was computed using these data. Discrete-time survival analysis was employed to test for intervention main and interaction effects with the polygenic score. We found main effect of the polygenic score approaching significance, with the participants with higher polygenic scores reporting their first smoking marijuana at an age significantly later than controls (p = .050). We also found a significant intervention × polygenic score interaction effect at p = .003, with participants at the higher end of the polygenic score benefiting the most from the intervention in terms of delayed age of first use. These results suggest that genetics may play an important role in the age of first use of marijuana and that differences in genetics may account for the differential effectiveness of classroom-based interventions in delaying substance use experimentation.

Survival and clinical outcome of dogs with ischaemic stroke

DEFF Research Database (Denmark)

Gredal, Hanne Birgit; Toft, Nils; Westrup, Ulrik

2013-01-01

The objectives of the present study were to investigate survival time, possible predictors of survival and clinical outcome in dogs with ischaemic stroke. A retrospective study of dogs with a previous diagnosis of ischaemic stroke diagnosed by magnetic resonance imaging (MRI) was performed....... The association between survival and the hypothesised risk factors was examined using univariable exact logistic regression. Survival was examined using Kaplan-Meier and Cox regression. Twenty-two dogs were identified. Five dogs (23%) died within the first 30days of the stroke event. Median survival in 30-day...... survivors was 505days. Four dogs (18%) were still alive by the end of the study. Right-sided lesions posed a significantly increased risk of mortality with a median survival time in dogs with right-sided lesions of 24days vs. 602days in dogs with left sided lesions (P=0.006). Clinical outcome was considered...

Survival period after tube feeding in bedridden older patients.

Science.gov (United States)

Kosaka, Yoichi; Nakagawa-Satoh, Takuma; Ohrui, Takashi; Fujii, Masahiko; Arai, Hiroyuki; Sasaki, Hidetada

2012-04-01

We prospectively studied survival periods after tube feeding. Participants were 163 bedridden older patients suffering from dysphagia. A wide range of survival periods after tube feeding were observed within half a year without tube feeding after being bedridden. After this initial period, survival periods after tube feeding were limited to approximately half a year. Survival periods after tube feeding were positively proportional to the length of time patients were free from pneumonia after tube feeding. After tube feeding, patients died from pneumonia within half a year, and the frequency of pneumonia was 3.1 ± 2.7 times (mean ± SD) before death. Survival periods after tube feeding for less than 1 year were primarily determined by being bedridden for more than half a year without tube feeding and once pneumonia occurred; patients who were tube fed did not survive for more than half a year. © 2012 Japan Geriatrics Society.

Chronic consequences of acute injuries: worse survival after discharge.

Science.gov (United States)

Shafi, Shahid; Renfro, Lindsay A; Barnes, Sunni; Rayan, Nadine; Gentilello, Larry M; Fleming, Neil; Ballard, David

2012-09-01

The Trauma Quality Improvement Program uses inhospital mortality to measure quality of care, which assumes patients who survive injury are not likely to suffer higher mortality after discharge. We hypothesized that survival rates in trauma patients who survive to discharge remain stable afterward. Patients treated at an urban Level I trauma center (2006-2008) were linked with the Social Security Administration Death Master File. Survival rates were measured at 30, 90, and 180 days and 1 and 2 years from injury among two groups of trauma patients who survived to discharge: major trauma (Abbreviated Injury Scale score ≥ 3 injuries, n = 2,238) and minor trauma (Abbreviated Injury Scale score ≤ 2 injuries, n = 1,171). Control groups matched to each trauma group by age and sex were simulated from the US general population using annual survival probabilities from census data. Kaplan-Meier and log-rank analyses conditional upon survival to each time point were used to determine changes in risk of mortality after discharge. Cox proportional hazards models with left truncation at the time of discharge were used to determine independent predictors of mortality after discharge. The survival rate in trauma patients with major injuries was 92% at 30 days posttrauma and declined to 84% by 3 years (p > 0.05 compared with general population). Minor trauma patients experienced a survival rate similar to the general population. Age and injury severity were the only independent predictors of long-term mortality given survival to discharge. Log-rank tests conditional on survival to each time point showed that mortality risk in patients with major injuries remained significantly higher than the general population for up to 6 months after injury. The survival rate of trauma patients with major injuries remains significantly lower than survival for minor trauma patients and the general population for several months postdischarge. Surveillance for early identification and treatment of

Protecting and rescuing the effectors: roles of differentiation and survival in the control of memory T cell development

Directory of Open Access Journals (Sweden)

Sema eKurtulus

2013-01-01

Full Text Available Vaccines, arguably the single most important intervention in improving human health, have exploited the phenomenon of immunological memory. The elicitation of memory T cells is often an essential part of successful long-lived protective immunity. Our understanding of T cell memory has been greatly aided by the development of TCR Tg mice and MHC tetrameric staining reagents that have allowed the precise tracking of antigen-specific T cell responses. Indeed, following acute infection or immunization, naïve T cells undergo a massive expansion culminating in the generation of a robust effector T cell population. This peak effector response is relatively short-lived and, while most effector T cells die by apoptosis, some remain and develop into memory cells. Although the molecular mechanisms underlying this cell fate decision remain incompletely defined, substantial progress has been made, particularly with regards to CD8+ T cells. For example, the effector CD8+ T cells generated during a response are heterogeneous, consisting of cells with more or less potential to develop into full-fledged memory cells. Development of CD8+ T cell memory is regulated by the transcriptional programs that control the differentiation and survival of effector T cells. While the type of antigenic stimulation and level of inflammation control effector CD8+ T cell differentiation, availability of cytokines and their ability to control expression and function of Bcl-2 family members governs their survival. These distinct differentiation and survival programs may allow for finer therapeutic intervention to control both the quality and quantity of CD8+ T cell memory. Effector to memory transition of CD4+ T cells is less well characterized than CD8+ T cells, emerging details will be discussed. This review will focus on the recent progress made in our understanding of the mechanisms underlying the development of T cell memory with an emphasis on factors controlling survival of

Development, survival and fitness performance of Helicoverpa zea (Lepidoptera: Noctuidae) in MON810 Bt field corn.

Science.gov (United States)

Horner, T A; Dively, G P; Herbert, D A

2003-06-01

Helicoverpa zea (Boddie) development, survival, and feeding injury in MON810 transgenic ears of field corn (Zea mays L.) expressing Bacillus thuringiensis variety kurstaki (Bt) Cry1Ab endotoxins were compared with non-Bt ears at four geographic locations over two growing seasons. Expression of Cry1Ab endotoxin resulted in overall reductions in the percentage of damaged ears by 33% and in the amount of kernels consumed by 60%. Bt-induced effects varied significantly among locations, partly because of the overall level and timing of H. zea infestations, condition of silk tissue at the time of egg hatch, and the possible effects of plant stress. Larvae feeding on Bt ears produced scattered, discontinuous patches of partially consumed kernels, which were arranged more linearly than the compact feeding patterns in non-Bt ears. The feeding patterns suggest that larvae in Bt ears are moving about sampling kernels more frequently than larvae in non-Bt ears. Because not all kernels express the same level of endotoxin, the spatial heterogeneity of toxin distribution within Bt ears may provide an opportunity for development of behavioral responses in H. zea to avoid toxin. MON810 corn suppressed the establishment and development of H. zea to late instars by at least 75%. This level of control is considered a moderate dose, which may increase the risk of resistance development in areas where MON810 corn is widely adopted and H. zea overwinters successfully. Sublethal effects of MON810 corn resulted in prolonged larval and prepupal development, smaller pupae, and reduced fecundity of H. zea. The moderate dose effects and the spatial heterogeneity of toxin distribution among kernels could increase the additive genetic variance for both physiological and behavioral resistance in H. zea populations. Implications of localized population suppression are discussed.

In-hospital resuscitation: opioids and other factors influencing survival

Directory of Open Access Journals (Sweden)

Karamarie Fecho

2009-12-01

Full Text Available Karamarie Fecho1, Freeman Jackson1, Frances Smith1, Frank J Overdyk21Department of Anesthesiology, University of North Carolina, Chapel Hill, North Carolina, USA; 2Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, South Carolina, USAPurpose: “Code Blue” is a standard term used to alertt hospital staff that a patient requires resuscitation. This study determined rates of survival from Code Blue events and the role of opioids and other factors on survival.Methods: Data derived from medical records and the Code Blue and Pharmacy databases were analyzed for factors affecting survival.Results: During 2006, rates of survival from the code only and to discharge were 25.9% and 26.4%, respectively, for Code Blue events involving cardiopulmonary resuscitation (CPR; N = 216. Survival rates for events not ultimately requiring CPR (N = 77 were higher, with 32.5% surviving the code only and 62.3% surviving to discharge. For CPR events, rates of survival to discharge correlated inversely with time to chest compressions and defibrillation, precipitating event, need for airway management, location and age. Time of week, witnessing, postoperative status, gender and opioid use did not influence survival rates. For non-CPR events, opioid use was associated with decreased survival. Survival rates were lowest for patients receiving continuous infusions (P < 0.01 or iv boluses of opioids (P < 0.05.Conclusions: One-quarter of patients survive to discharge after a CPR Code Blue event and two-thirds survive to discharge after a non-CPR event. Opioids may influence survival from non-CPR events.Keywords: code blue, survival, opioids, cardiopulmonary resuscitation, cardiac arrest, patient safety

Prognostic and survival analysis of presbyopia: The healthy twin study

Science.gov (United States)

Lira, Adiyani; Sung, Joohon

2015-12-01

Presbyopia, a vision condition in which the eye loses its flexibility to focus on near objects, is part of ageing process which mostly perceptible in the early or mid 40s. It is well known that age is its major risk factor, while sex, alcohol, poor nutrition, ocular and systemic diseases are known as common risk factors. However, many other variables might influence the prognosis. Therefore in this paper we developed a prognostic model to estimate survival from presbyopia. 1645 participants which part of the Healthy Twin Study, a prospective cohort study that has recruited Korean adult twins and their family members based on a nation-wide registry at public health agencies since 2005, were collected and analyzed by univariate analysis as well as Cox proportional hazard model to reveal the prognostic factors for presbyopia while survival curves were calculated by Kaplan-Meier method. Besides age, sex, diabetes, and myopia; the proposed model shows that education level (especially engineering program) also contribute to the occurrence of presbyopia as well. Generally, at 47 years old, the chance of getting presbyopia becomes higher with the survival probability is less than 50%. Furthermore, our study shows that by stratifying the survival curve, MZ has shorter survival with average onset time about 45.8 compare to DZ and siblings with 47.5 years old. By providing factors that have more effects and mainly associate with presbyopia, we expect that we could help to design an intervention to control or delay its onset time.

Extensions and Applications of the Cox-Aalen Survival Model

DEFF Research Database (Denmark)

Scheike, Thomas H.; Zhang, Mei-Jie

2003-01-01

Aalen additive risk model; competing risk; counting processes; Cox model; cumulative incidence function; goodness of fit; prediction of survival probability; time-varying effects......Aalen additive risk model; competing risk; counting processes; Cox model; cumulative incidence function; goodness of fit; prediction of survival probability; time-varying effects...

The effect of environment on development and survival of pupae of the necrophagous fly Ophyra albuquerquei Lopes (Diptera, Muscidae

Directory of Open Access Journals (Sweden)

Rodrigo Ferreira Krüger

2011-09-01

Full Text Available The effect of environment on development and survival of pupae of the necrophagous fly Ophyra albuquerquei Lopes (Diptera, Muscidae. Species of Ophyra Robineau-Desvoidy, 1830 are found in decomposing bodies, usually in fresh, bloated and decay stages. Ophyra albuquerquei Lopes, for example, can be found in animal carcasses. The influence of environmental factors has not been evaluated in puparia of O. albuquerquei. Thus, the focus of this work was motivated by the need for models to predict the development of a necrophagous insect as a function of abiotic factors. Colonies of O. albuquerquei were maintained in the laboratory to obtain pupae. On the tenth day of each month 200 pupae, divided equally into 10 glass jars, were exposed to the environment and checked daily for adult emergence of each sample. We concluded that the high survival rate observed suggested that the diets used for rearing the larvae and maintaining the adults were appropriate. Also, the data adjusted to robust generalized linear models and there were no interruptions of O. albuquerquei pupae development within the limits of temperatures studied in southern Rio Grande do Sul, given the high survival presented.

Malignant melanoma in 63 dogs (2001-2011): the effect of carboplatin chemotherapy on survival.

Science.gov (United States)

Brockley, L K; Cooper, M A; Bennett, P F

2013-01-01

The aim of the study was to compare the effect of carboplatin chemotherapy on the survival of canine patients diagnosed with malignant melanoma after loco-regional control or as a sole therapy. A retrospective study of 63 dogs with oral, digital or cutaneous malignant melanoma treated with surgery and/or chemotherapy was undertaken. Dogs were grouped based on the anatomical site of melanoma development. For oral melanoma, dogs were subclassified into two groups: loco-regional control and gross disease. All patients in the digital and cutaneous groups had achieved loco-regional control with surgery. Comparisons between survival data for each group at each anatomical site were then made. Within the loco-regional control groups survival time was compared between those treated with and without chemotherapy post surgery. For the oral melanoma patients with gross disease survival was compared between those treated with chemotherapy and palliative therapy. The toxicity of carboplatin chemotherapy was evaluated overall. The overall median survival times for patients with oral, digital and cutaneous melanoma were 389, 1,350 days and not reached (with a median follow-up of 776 days) respectively. Median survival time was defined as "not reached" when less than 50% of the subjects died of the disease at the end of the follow-up period, or at the time they were lost to follow-up. The addition of chemotherapy to surgery did not confer a survival benefit in the loco-regional control setting when assessing survival for each anatomical site. For oral melanoma patients with gross disease there was no difference between survival of patients treated with chemotherapy and palliative intent therapy. There was however an improvement in survival in the three dogs that responded to chemotherapy (978 days; p=0.039) compared to the eight non-responders (147 days). On univariate and multivariate analysis, anatomic location was the only variable that was significantly related to survival (p=0

Survival of Lactobacillus plantarumU40 on the in vitro rumen fermentation quantified with real-time PCR

Directory of Open Access Journals (Sweden)

W.D. Astuti

2018-05-01

Full Text Available The objective of this study was to evaluate the survival of L. plantarumU40 quantified with real-time PCR during in vitro rumen fermentation. The experiment was arranged in a randomized block design with 3 treatments and 4 replications. Treatments were control, rumen fermentation inoculated with L. plantarumU40and L. plantarumU40 + glucose solution. Population of L. plantarum U40 was higher at inoculation treatment. After 8 hours incubation, glucose addition tended to decrease L. plantarum U40 population. Control treatment showed lowest population of L. plantarum U40 along in vitro fermentation compared with other treatment. Inoculation of L. plantarumU40 significantly (p<0.05 increased population of LAB until 12 hours incubation compared with control. Control treatment had highest pH at all incubation time. Glucose addition significantly (P<0.05 decreased final rumen pH (24 hours (6.30, compared with control treatment (6.85. Inoculation of L. plantarum U40 with glucose addition significantly (P<0.05increased propionic acid, decreased acetic acid and A/P ratio compared with other treatments. Lactobacillus plantarum U40 without glucose addition did not affect propionic acid production significantly. As conclusion, Lactobacillus plantarum U40 can survive in rumen fluid and changes rumen fermentation when glucose is added as carbon source.

Elements of a war-survival policy for the United States

International Nuclear Information System (INIS)

Chester, C.V.

1978-01-01

The Soviet Union has been vigorously pursuing a war-survival policy for several years, whereas the United States has relied entirely on deterring nuclear war. This has resulted in a situation in which the U.S. population is of the order of ten times more vulnerable to nuclear war than is the Soviet population. Increasingly wide-spread perception of the disparity in vulnerability could undermine credibility of the U.S. deterrent forces and leave the United States in a very poor bargaining position in a confrontation. A program recommended to reestablish parity in vulnerability consists of the following: (1) make national survival in the event of nuclear war explicit policy, (2) develop crisis relocation plans for the population of all potential target areas, (3) teach a course in nuclear-war survival in high school, (4) assign to Minuteman and/or B-1 the role of preventing the reloading of Soviet pop-up silos, (5) reinstitute air defense in the United States if the Soviets continue to deploy the Backfire bomber, (6) continue policies encouraging relocation of population and industry outside cities, (7) avoid the development of new target concentrations especially in the new synthetic liquid fuel industry, and (8) develop and encourage integration of blast and fallout protection into new energy-conserving construction

Polycyclic aromatic hydrocarbons affect survival and development of common snapping turtle (Chelydra serpentina) embryos and hatchlings

Energy Technology Data Exchange (ETDEWEB)

Van Meter, Robin J [School of Environmental Science, Engineering, and Policy and Department of Bioscience and Biotechnology, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Spotila, James R [School of Environmental Science, Engineering, and Policy and Department of Bioscience and Biotechnology, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Avery, Harold W [School of Environmental Science, Engineering, and Policy and Department of Bioscience and Biotechnology, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)

2006-08-15

Polycyclic aromatic hydrocarbons (PAHs) are toxic compounds found in the John Heinz National Wildlife Refuge in Philadelphia, Pennsylvania. We assessed the impact of PAHs and crude oil on snapping turtle development and behavior by exposing snapping turtle eggs from the Refuge and from three clean reference sites to individual PAHs or a crude oil mixture at stage 9 of embryonic development. Exposure to PAHs had a significant effect on survival rates in embryos from one clean reference site, but not in embryos from the other sites. There was a positive linear relationship between level of exposure to PAHs and severity of deformities in embryos collected from two of the clean reference sites. Neither righting response nor upper temperature tolerance (critical thermal maximum, CTM) of snapping turtle hatchlings with no or minor deformities was significantly affected by exposure to PAHs. - Exposure to polycyclic aromatic hydrocarbons on the egg reduces survival of snapping turtle embryos and causes developmental abnormalities.

Polycyclic aromatic hydrocarbons affect survival and development of common snapping turtle (Chelydra serpentina) embryos and hatchlings

International Nuclear Information System (INIS)

Van Meter, Robin J.; Spotila, James R.; Avery, Harold W.

2006-01-01

Polycyclic aromatic hydrocarbons (PAHs) are toxic compounds found in the John Heinz National Wildlife Refuge in Philadelphia, Pennsylvania. We assessed the impact of PAHs and crude oil on snapping turtle development and behavior by exposing snapping turtle eggs from the Refuge and from three clean reference sites to individual PAHs or a crude oil mixture at stage 9 of embryonic development. Exposure to PAHs had a significant effect on survival rates in embryos from one clean reference site, but not in embryos from the other sites. There was a positive linear relationship between level of exposure to PAHs and severity of deformities in embryos collected from two of the clean reference sites. Neither righting response nor upper temperature tolerance (critical thermal maximum, CTM) of snapping turtle hatchlings with no or minor deformities was significantly affected by exposure to PAHs. - Exposure to polycyclic aromatic hydrocarbons on the egg reduces survival of snapping turtle embryos and causes developmental abnormalities

A retrospective analysis of survival outcomes for two different radiotherapy fractionation schedules given in the same overall time for limited stage small cell lung cancer

International Nuclear Information System (INIS)

Bettington, Catherine S.; Bryant, Guy; Hickey, Brigid; Tripcony, Lee; Pratt, Gary; Fay, Michael

2013-01-01

To compare survival outcomes for two fractionation schedules of thoracic radiotherapy, both given over 3 weeks, in patients with limited stage small cell lung cancer (LS-SCLC). At Radiation Oncology Mater Centre (ROMC) and the Royal Brisbane and Women's Hospital (RBWH), patients with LS-SCLC treated with curative intent are given radiotherapy (with concurrent chemotherapy) to a dose of either 40Gy in 15 fractions ('the 40Gy/15⧣group') or 45Gy in 30 fractions ('the 45Gy/30⧣group'). The choice largely depends on institutional preference. Both these schedules are given over 3 weeks, using daily and twice-daily fractionation respectively. The records of all such patients treated from January 2000 to July 2009 were retrospectively reviewed and survival outcomes between the two groups compared. Of 118 eligible patients, there were 38 patients in the 40Gy/15⧣ group and 41 patients in the 45Gy/30⧣ group. The median relapse-free survival time was 12 months in both groups. Median overall survival was 21 months (95% CI 2–37 months) in the 40Gy/15⧣ group and 26 months (95% CI 1–48 months) in the 45Gy/30⧣ group. The 5-year overall survival rates were 20% and 25%, respectively (P=0.24). On multivariate analysis, factors influencing overall survival were: whether prophylactic cranial irradiation (PCI) was given (P=0.01) and whether salvage chemotherapy was given at the time of relapse (P=0.057). Given the small sample size, the potential for selection bias and the retrospective nature of our study it is not possible to draw firm conclusions regarding the efficacy of hypofractionated thoracic radiotherapy compared with hyperfractionated accelerated thoracic radiotherapy however hypofractionated radiotherapy may result in equivalent relapse-free survival.

Foxp1 controls mature B cell survival and the development of follicular and B-1 B cells

Science.gov (United States)

Patzelt, Thomas; Keppler, Selina J.; Gorka, Oliver; Thoene, Silvia; Wartewig, Tim; Reth, Michael; Förster, Irmgard; Lang, Roland; Buchner, Maike; Ruland, Jürgen

2018-01-01

The transcription factor Foxp1 is critical for early B cell development. Despite frequent deregulation of Foxp1 in B cell lymphoma, the physiological functions of Foxp1 in mature B cells remain unknown. Here, we used conditional gene targeting in the B cell lineage and report that Foxp1 disruption in developing and mature B cells results in reduced numbers and frequencies of follicular and B-1 B cells and in impaired antibody production upon T cell-independent immunization in vivo. Moreover, Foxp1-deficient B cells are impaired in survival even though they exhibit an increased capacity to proliferate. Transcriptional analysis identified defective expression of the prosurvival Bcl-2 family gene Bcl2l1 encoding Bcl-xl in Foxp1-deficient B cells, and we identified Foxp1 binding in the regulatory region of Bcl2l1. Transgenic overexpression of Bcl2 rescued the survival defect in Foxp1-deficient mature B cells in vivo and restored peripheral B cell numbers. Thus, our results identify Foxp1 as a physiological regulator of mature B cell survival mediated in part via the control of Bcl-xl expression and imply that this pathway might contribute to the pathogenic function of aberrant Foxp1 expression in lymphoma. PMID:29507226

Predicting and Modelling of Survival Data when Cox's Regression Model does not hold

DEFF Research Database (Denmark)

Scheike, Thomas H.; Zhang, Mei-Jie

2002-01-01

Aalen model; additive risk model; counting processes; competing risk; Cox regression; flexible modeling; goodness of fit; prediction of survival; survival analysis; time-varying effects......Aalen model; additive risk model; counting processes; competing risk; Cox regression; flexible modeling; goodness of fit; prediction of survival; survival analysis; time-varying effects...

Expectation-maximization algorithms for learning a finite mixture of univariate survival time distributions from partially specified class values

Energy Technology Data Exchange (ETDEWEB)

Lee, Youngrok [Iowa State Univ., Ames, IA (United States)

2013-05-15

Heterogeneity exists on a data set when samples from di erent classes are merged into the data set. Finite mixture models can be used to represent a survival time distribution on heterogeneous patient group by the proportions of each class and by the survival time distribution within each class as well. The heterogeneous data set cannot be explicitly decomposed to homogeneous subgroups unless all the samples are precisely labeled by their origin classes; such impossibility of decomposition is a barrier to overcome for estimating nite mixture models. The expectation-maximization (EM) algorithm has been used to obtain maximum likelihood estimates of nite mixture models by soft-decomposition of heterogeneous samples without labels for a subset or the entire set of data. In medical surveillance databases we can find partially labeled data, that is, while not completely unlabeled there is only imprecise information about class values. In this study we propose new EM algorithms that take advantages of using such partial labels, and thus incorporate more information than traditional EM algorithms. We particularly propose four variants of the EM algorithm named EM-OCML, EM-PCML, EM-HCML and EM-CPCML, each of which assumes a specific mechanism of missing class values. We conducted a simulation study on exponential survival trees with five classes and showed that the advantages of incorporating substantial amount of partially labeled data can be highly signi cant. We also showed model selection based on AIC values fairly works to select the best proposed algorithm on each specific data set. A case study on a real-world data set of gastric cancer provided by Surveillance, Epidemiology and End Results (SEER) program showed a superiority of EM-CPCML to not only the other proposed EM algorithms but also conventional supervised, unsupervised and semi-supervised learning algorithms.

Interaction of defibrillation waveform with the time to defibrillation or the number of defibrillation attempts on survival from out-of-hospital cardiac arrest.

Science.gov (United States)

Hagihara, Akihito; Onozuka, Daisuke; Ono, Junko; Nagata, Takashi; Hasegawa, Manabu

2018-01-01

Early biphasic defibrillation is effective in out-of-hospital cardiac arrest (OHCA) cases. In the resuscitation of patients with OHCA, it is not clear how the defibrillation waveform interacts with the time to defibrillation to influence patient survival. The second, and any subsequent, shocks need to be administered by an on-line physician in Japan. Thus, we investigated the interaction between the defibrillation waveform and time to or the number of defibrillation on resuscitation outcomes. This prospective observational study used data for all OHCAs that occurred between 2005 and 2014 in Japan. To investigate the interaction effect between the defibrillation waveform and the time to defibrillation or the number of defibrillations on the return to spontaneous circulation (ROSC), 1-month survival, and cerebral performance category (CPC) (1, 2), we assessed the modifying effects of the defibrillation waveform and the time to or the number of defibrillation on additive scale (i.e., the relative excessive risk due to interaction, RERI) and multiplicative scale (i.e., ratio of odds ratios (ORs)). In total, 71,566 cases met the inclusion criteria. For the measure of interaction between the defibrillation waveform and the time to defibrillation, ratio of ORs for ROSC was 0.84 (0.75-0.94), implying that the effect of time to first defibrillation on ROSC was negatively modified by defibrillation waveform. For the interaction between the defibrillation waveform and the number of defibrillations, RERI and ratio of ORs for CPC (1, 2) was -0.25 (-0.47 to -0.06) and 0.79 (0.67-0.93), respectively. It is implied that the effect of number of defibrillation on CPC (1, 2) was negatively modified by defibrillation waveform. An increased number of defibrillations was associated with a decreased ROSC in the case of biphasic and monophasic defibrillation, while an increased number of defibrillations was related to an increased 1-month survival rate and CPC (1, 2) only in the case of

The risk of falling into poverty after developing heart disease: a survival analysis.

Science.gov (United States)

Callander, Emily J; Schofield, Deborah J

2016-07-15

Those with a low income are known to have a higher risk of developing heart disease. However, the inverse relationship - falling into income poverty after developing heart disease has not been explored with longitudinal data. This paper aims to determine if those with heart disease have an elevated risk of falling into poverty. Survival analysis was conducted using the longitudinal Household Income and Labour Dynamics in Australia survey, between the years 2007 and 2012. The study focused on the Australian population aged 21 years and over in 2007 who were not already in poverty and did not already have heart disease, who were followed from 2007 to 2012. Cox regression models adjusting for age, sex and time-varying co-variates (marital status, home ownership and remoteness of area of residence) were constructed to assess the risk of falling into poverty. For those aged 20 who developed heart disease, the hazard ratio for falling into income poverty was 9.24 (95 % CI: 8.97-9.51) and for falling into multidimensional poverty the hazard ratio was 14.21 (95 % CI: 13.76-14.68); for those aged 40 the hazard ratio for falling into income poverty was 3.45 (95 % CI: 3.39-3.51) and for multidimensional poverty, 5.20 (95 % CI: 5.11-5.29); and for those aged 60 the hazard ratio for falling into income poverty was 1.29 (95 % CI: 1.28-1.30) and for multidimensional poverty, 1.52 (95 % CI: 1.51-1.54), relative those who never developed heart disease. The risk for both income and multidimensional poverty decreases with age up to the age of 70, over which, those who developed heart disease had a reduced risk of poverty. For those under the age of 70, developing heart disease is associated with an increased risk of falling into both income poverty and multidimensional poverty.

Ingestion of Bt rice pollen does not reduce the survival or hypopharyngeal gland development of Apis mellifera adults.

Science.gov (United States)

Wang, Yuanyuan; Dai, Pingli; Chen, Xiuping; Romeis, Jörg; Shi, Jianrong; Peng, Yufa; Li, Yunhe

2017-05-01

Because of its ecological and economic importance, the honey bee Apis mellifera is commonly used to assess the environmental risk of insect-resistant, genetically modified plants. In the present study, feeding-exposure experiments were used to determine whether pollen from transgenic rice harms A. mellifera worker bees. In 1 experiment, the survival and mean acinus diameter of hypopharyngeal glands of adult bees were similar when bees were fed on pollen from Bt rice lines or from a non-Bt rice line, but bee survival was significantly reduced when they received pollen that was mixed with potassium arsenate as a positive control. In a second experiment, bee survival and hypopharyngeal gland development were not reduced when adult bees were fed on non-Bt pollen and a sucrose solution supplemented with Cry2A at 400 µg/g, Cry1C at 50 µg/g, or bovine serum albumin (BSA) at 400 µg/g, but bee survival and hypopharyngeal gland development were reduced when the diet was supplemented with soybean trypsin inhibitor as a positive control. In both experiments, the uptake of Cry proteins by adult bees was confirmed. Overall, the results indicate that the planting of Bt rice lines expressing Cry2A or Cry1C protein poses a negligible risk to A. mellifera worker bees. Environ Toxicol Chem 2017;36:1243-1248. © 2016 SETAC. © 2016 SETAC.

Survival associated pathway identification with group Lp penalized global AUC maximization

Directory of Open Access Journals (Sweden)

Liu Zhenqiu

2010-08-01

Full Text Available Abstract It has been demonstrated that genes in a cell do not act independently. They interact with one another to complete certain biological processes or to implement certain molecular functions. How to incorporate biological pathways or functional groups into the model and identify survival associated gene pathways is still a challenging problem. In this paper, we propose a novel iterative gradient based method for survival analysis with group Lp penalized global AUC summary maximization. Unlike LASSO, Lp (p 1. We first extend Lp for individual gene identification to group Lp penalty for pathway selection, and then develop a novel iterative gradient algorithm for penalized global AUC summary maximization (IGGAUCS. This method incorporates the genetic pathways into global AUC summary maximization and identifies survival associated pathways instead of individual genes. The tuning parameters are determined using 10-fold cross validation with training data only. The prediction performance is evaluated using test data. We apply the proposed method to survival outcome analysis with gene expression profile and identify multiple pathways simultaneously. Experimental results with simulation and gene expression data demonstrate that the proposed procedures can be used for identifying important biological pathways that are related to survival phenotype and for building a parsimonious model for predicting the survival times.

Exposure to aged crumb rubber reduces survival time during a stress test in earthworms (Eisenia fetida).

Science.gov (United States)

Pochron, Sharon; Nikakis, Jacqueline; Illuzzi, Kyra; Baatz, Andrea; Demirciyan, Loriana; Dhillon, Amritjot; Gaylor, Thomas; Manganaro, Alexa; Maritato, Nicholas; Moawad, Michael; Singh, Rajwinder; Tucker, Clara; Vaughan, Daniel

2018-04-01

Solid waste management struggles with the sustainable disposal of used tires. One solution involves shredding used tires into crumb rubber and using the material as infill for artificial turf. However, crumb rubber contains hydrocarbons, organic compounds, and heavy metals, and it travels into the environment. Earthworms living in soil contaminated with virgin crumb rubber gained 14% less body weight than did earthworms living in uncontaminated soil, but the impact of aged crumb rubber on the earthworms is unknown. Since many athletic fields contain aged crumb rubber, we compared the body weight, survivorship, and longevity in heat and light stress for earthworms living in clean topsoil to those living in topsoil contaminated with aged crumb rubber. We also characterized levels of metals, nutrients, and micronutrients of both soil treatments and compared those to published values for soil contaminated with virgin crumb rubber. Consistent with earlier research, we found that contaminated soil did not inhibit microbial respiration rates. Aged crumb rubber, like new crumb rubber, had high levels of zinc. However, while exposure to aged crumb rubber did not reduce earthworm body weight as did exposure to new crumb rubber, exposure to aged crumb rubber reduced earthworm survival time during a stress test by a statistically significant 38 min (16.2%) relative to the survival time for worms that had lived in clean soil. Aged crumb rubber and new crumb rubber appear to pose similar toxic risks to earthworms. This study suggests an environmental cost associated with the current tire-recycling solution.

Denosumab and bone metastasis-free survival in men with nonmetastatic castration-resistant prostate cancer: exploratory analyses by baseline prostate-specific antigen doubling time.

Science.gov (United States)

Smith, Matthew R; Saad, Fred; Oudard, Stephane; Shore, Neal; Fizazi, Karim; Sieber, Paul; Tombal, Bertrand; Damiao, Ronaldo; Marx, Gavin; Miller, Kurt; Van Veldhuizen, Peter; Morote, Juan; Ye, Zhishen; Dansey, Roger; Goessl, Carsten

2013-10-20

Denosumab, an anti-RANK ligand monoclonal antibody, significantly increases bone metastasis-free survival (BMFS; hazard ratio [HR], 0.85; P = .028) and delays time to first bone metastasis in men with nonmetastatic castration-resistant prostate cancer (CRPC) and baseline prostate-specific antigen (PSA) ≥ 8.0 ng/mL and/or PSA doubling time (PSADT) ≤ 10.0 months. To identify men at greatest risk for bone metastasis or death, we evaluated relationships between PSA and PSADT with BMFS in the placebo group and the efficacy and safety of denosumab in men with PSADT ≤ 10, ≤ 6, and ≤ 4 months. A total of 1,432 men with nonmetastatic CRPC were randomly assigned 1:1 to monthly subcutaneous denosumab 120 mg or placebo. Enrollment began February 2006; primary analysis cutoff was July 2010, when approximately 660 men were anticipated to have developed bone metastases or died. In the placebo group, shorter BMFS was observed as PSADT decreased below 8 months. In analyses by shorter baseline PSADT, denosumab consistently increased BMFS by a median of 6.0, 7.2, and 7.5 months among men with PSADT ≤ 10 (HR, 0.84; P = .042), ≤ 6 (HR, 0.77; P = .006), and ≤ 4 months (HR, 0.71; P = .004), respectively. Denosumab also consistently increased time to bone metastasis by PSADT subset. No difference in survival was observed between treatment groups for the overall study population or PSADT subsets. Patients with shorter PSADT are at greater risk for bone metastasis or death. Denosumab consistently improves BMFS in men with shorter PSADT and seems to have the greatest treatment effects in men at high risk for progression.

Human umbilical cord mesenchymal stromal cells suppress MHC class II expression on rat vascular endothelium and prolong survival time of cardiac allograft

Science.gov (United States)

Qiu, Ying; Yun, Mark M; Han, Xia; Zhao, Ruidong; Zhou, Erxia; Yun, Sheng

2014-01-01

Background: Human umbilical cord mesenchymal stromal cells (UC-MSCs) have low immunogenicity and immune regulation. To investigate immunomodulatory effects of human UC-MSCs on MHC class II expression and allograft, we transplanted heart of transgenic rats with MHC class II expression on vascular endothelium. Methods: UC-MSCs were obtained from human umbilical cords and confirmed with flow cytometry analysis. Transgenic rat line was established using the construct of human MHC class II transactivator gene (CIITA) under mouse ICAM-2 promoter control. The induced MHC class II expression on transgenic rat vascular endothelial cells (VECs) was assessed with immunohistological staining. And the survival time of cardiac allograft was compared between the recipients with and without UC-MSC transfusion. Results: Flow cytometry confirmed that the human UC-MSCs were positive for CD29, CD44, CD73, CD90, CD105, CD271, and negative for CD34 and HLA-DR. Repeated infusion of human UC-MSCs reduced MHC class II expression on vascular endothelia of transplanted hearts, and increased survival time of allograft. The UC-MSCs increased regulatory cytokines IL10, transforming growth factor (TGF)-β1 and suppressed proinflammatory cytokines IL2 and IFN-γ in vivo. The UC-MSC culture supernatant had similar effects on cytokine expression, and decreased lymphocyte proliferation in vitro. Conclusions: Repeated transfusion of the human UC-MSCs reduced MHC class II expression on vascular endothelia and prolonged the survival time of rat cardiac allograft. PMID:25126177

Prehospital cardiac arrest survival and neurologic recovery.

Science.gov (United States)

Hillis, M; Sinclair, D; Butler, G; Cain, E

1993-01-01

Many studies of prehospital defibrillation have been conducted but the effects of airway intervention are unknown and neurologic follow-up has been incomplete. A non-randomized cohort prospective study was conducted to determine the effectiveness of defibrillation in prehospital cardiac arrest. Two ambulance companies in the study area developed a defibrillation protocol and they formed the experimental group. A subgroup of these patients received airway management with an esophageal obturator airway (EOA) or endotracheal intubation (ETT). The control group was composed of patients who suffered a prehospital cardiac arrest and did not receive prehospital defibrillation. All survivors were assessed for residual deficits using the Sickness Impact Profile (SIP) and the Dementia Rating Scale (DRS). A total of 221 patients were studied over a 32-month period. Both the experimental group (N = 161) and the control group (N = 60) were comparable with respect to age, sex distribution, and ambulance response time. Survival to hospital discharge was 2/60 (3.3%) in the control group and 12/161 (6.3%) in the experimental group. This difference is not statistically significant. Survival in the experimental group by airway management technique was basic airway support (3/76 3.9%), EOA (3/67 4.5%), and ETT (6/48 12.5%). The improved effect on survival by ETT management was statistically significant. Survivors had minor differences in memory, work, and recreation as compared to ischemic heart disease patients as measured by the SIP and DRS. No effect of defibrillation was found on survival to hospital discharge. However, endotracheal intubation improved survival in defibrillated patients. Survivors had a good functional outcome.

Development and External Validation of Prognostic Model for 2-Year Survival of Non-Small-Cell Lung Cancer Patients Treated With Chemoradiotherapy

International Nuclear Information System (INIS)

Dehing-Oberije, Cary; Yu Shipeng; De Ruysscher, Dirk; Meersschout, Sabine; Van Beek, Karen; Lievens, Yolande; Van Meerbeeck, Jan; De Neve, Wilfried; Rao, Bharat Ph.D.; Weide, Hiska van der; Lambin, Philippe

2009-01-01

Purpose: Radiotherapy, combined with chemotherapy, is the treatment of choice for a large group of non-small-cell lung cancer (NSCLC) patients. Recent developments in the treatment of these patients have led to improved survival. However, the clinical TNM stage is highly inaccurate for the prediction of survival, and alternatives are lacking. The objective of this study was to develop and validate a prediction model for survival of NSCLC patients, treated with chemoradiotherapy. Patients and Methods: The clinical data from 377 consecutive inoperable NSCLC patients, Stage I-IIIB, treated radically with chemoradiotherapy were collected. A prognostic model for 2-year survival was developed, using 2-norm support vector machines. The performance of the model was expressed as the area under the curve of the receiver operating characteristic and assessed using leave-one-out cross-validation, as well as two external data sets. Results: The final multivariate model consisted of gender, World Health Organization performance status, forced expiratory volume in 1 s, number of positive lymph node stations, and gross tumor volume. The area under the curve, assessed by leave-one-out cross-validation, was 0.74, and application of the model to the external data sets yielded an area under the curve of 0.75 and 0.76. A high- and low-risk group could be clearly identified using a risk score based on the model. Conclusion: The multivariate model performed very well and was able to accurately predict the 2-year survival of NSCLC patients treated with chemoradiotherapy. The model could support clinicians in the treatment decision-making process.

Vitamin D Depletion in Pregnancy Decreases Survival Time, Oxygen Saturation, Lung Weight and Body Weight in Preterm Rat Offspring

DEFF Research Database (Denmark)

Lykkedegn, Sine; Sorensen, Grith Lykke; Beck-Nielsen, Signe Sparre

2016-01-01

Animal studies suggest a role of vitamin D in fetal lung development although not studied in preterm animals. We tested the hypothesis that vitamin D depletion aggravates respiratory insufficiency in preterm rat offspring. Furthermore, the effects of vitamin D depletion on growth and lung...... surfactant were investigated. Female Sprague-Dawley rats were randomly assigned low vitamin D (VDL) or control diet before mating and followed with serum 25-hydroxyvitamin D (s-25(OH)D) determinations. After cesarean section at gestational day 19 (E19) or day 22 (E22), placental weight, birth weight, crown......-rump-length (CRL), oxygenation (SaO2) at 30 min and survival time were recorded. The pup lungs were analyzed for phospholipid levels, surfactant protein A-D mRNA and the expression of the vitamin D receptor (VDR). S-25(OH)D was significantly lower in the VDL group at cesarean section (12 vs. 30nmol/L, p

Survival and larval development of Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) on alternatives host; Sobrevivencia e desenvolvimento larval de Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) em hospedeiros alternativos

Energy Technology Data Exchange (ETDEWEB)

Sa, Verissimo G.M. de [Universidade Federal de Minas Gerais (UFMG), Montes Claros, MG (Brazil). Dept. de Agronomia; Fonseca, Bernardo V.C. [Universidade FUMEC, Belo Horizonte, MG (Brazil); Boregas, Katia G.B. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Ecologia; Waquil, Jose M. [EMBRAPA Milho e Sorgo, Sete Lagoas, MG (Brazil)]. E-mail: aaquil@cnpms.embrapa.br

2009-01-15

Two bioassays were conducted to evaluate the suitability of host plants of fall armyworm (FAW), Spodoptera frugiperda (J E Smith), in the Brazilian agro-ecosystem. Larval development and survival were analyzed by infesting leaves of maize, grain sorghum, Johnson grass, soybean, Brachiaria and tobacco with FAW newly hatched larvae in a no choice test. No significant differences of survival were observed among insects reared on different hosts, except for tobacco, where no survivors were recorded. Larvae fed on soybean and artificial diet grew larger than those fed on the other hosts. The heaviest pupa was observed from larva fed on artificial diet and the lighter from larva fed on Brachiaria grass. No significant differences were reported on larval development time on natural hosts, but it was longer for larvae reared on artificial diet. Three classes of larval development time were observed on maize, four on sorghum, Brachiaria and soybean, and five on artificial diet. Nearly 85% of FAW larvae completed development within 12 d on maize; 77% on grain sorghum, 80% on Johnson grass, 68% on Brachiaria and 83% on soybean within 14 d and 69% on artificial diet within 17 d. The host suitability to FAW decreases from maize to sorghum, soybean and Brachiaria. (author)

Endogenous TSH levels at the time of 131I ablation do not influence ablation success, recurrence-free survival or differentiated thyroid cancer-related mortality

International Nuclear Information System (INIS)

Vrachimis, Alexis; Riemann, Burkhard; Maeder, Uwe; Reiners, Christoph; Verburg, Frederik A.

2016-01-01

Based on a single older study it is established dogma that TSH levels should be ≥30 mU/l at the time of postoperative 131 I ablation in differentiated thyroid cancer (DTC) patients. We sought to determine whether endogenous TSH levels, i.e. after levothyroxine withdrawal, at the time of ablation influence ablation success rates, recurrence-free survival and DTC-related mortality. A total of 1,873 patients without distant metastases referred for postoperative adjuvant 131 I therapy were retrospectively included from 1991 onwards. Successful ablation was defined as stimulated Tg <1 μg/l. Age, gender and the presence of lymph node metastases were independent determinants of TSH levels at the time of ablation. TSH levels were not significantly related to ablation success rates (p = 0.34), recurrence-free survival (p = 0.29) or DTC -elated mortality (p = 0.82), but established risk factors such as T-stage, lymph node metastases and age were. Ablation was successful in 230 of 275 patients (83.6 %) with TSH <30 mU/l and in 1,359 of 1,598 patients (85.0 %) with TSH ≥30 mU/l. The difference was not significant (p = 0.55). Of the whole group of 1,873 patients, 21 had recurrent disease. There were no significant differences in recurrence rates between patients with TSH <30 mU/l and TSH ≥30 mU/l (p = 0.16). Ten of the 1,873 patients died of DTC. There were no significant differences in DTC-specific survival between patients with TSH <30 mU/l and TSH ≥30 mU/l (p = 0.53). The precise endogenous TSH levels at the time of 131 I ablation are not related to the ablation success rates, recurrence free survival and DTC related mortality. The established dogma that TSH levels need to be ≥30 mU/l at the time of 131 I ablation can be discarded. (orig.)

TH-E-BRF-05: Comparison of Survival-Time Prediction Models After Radiotherapy for High-Grade Glioma Patients Based On Clinical and DVH Features

International Nuclear Information System (INIS)

Magome, T; Haga, A; Igaki, H; Sekiya, N; Masutani, Y; Sakumi, A; Mukasa, A; Nakagawa, K

2014-01-01

Purpose: Although many outcome prediction models based on dose-volume information have been proposed, it is well known that the prognosis may be affected also by multiple clinical factors. The purpose of this study is to predict the survival time after radiotherapy for high-grade glioma patients based on features including clinical and dose-volume histogram (DVH) information. Methods: A total of 35 patients with high-grade glioma (oligodendroglioma: 2, anaplastic astrocytoma: 3, glioblastoma: 30) were selected in this study. All patients were treated with prescribed dose of 30–80 Gy after surgical resection or biopsy from 2006 to 2013 at The University of Tokyo Hospital. All cases were randomly separated into training dataset (30 cases) and test dataset (5 cases). The survival time after radiotherapy was predicted based on a multiple linear regression analysis and artificial neural network (ANN) by using 204 candidate features. The candidate features included the 12 clinical features (tumor location, extent of surgical resection, treatment duration of radiotherapy, etc.), and the 192 DVH features (maximum dose, minimum dose, D95, V60, etc.). The effective features for the prediction were selected according to a step-wise method by using 30 training cases. The prediction accuracy was evaluated by a coefficient of determination (R 2 ) between the predicted and actual survival time for the training and test dataset. Results: In the multiple regression analysis, the value of R 2 between the predicted and actual survival time was 0.460 for the training dataset and 0.375 for the test dataset. On the other hand, in the ANN analysis, the value of R 2 was 0.806 for the training dataset and 0.811 for the test dataset. Conclusion: Although a large number of patients would be needed for more accurate and robust prediction, our preliminary Result showed the potential to predict the outcome in the patients with high-grade glioma. This work was partly supported by the JSPS Core

Instrumental variables estimation of exposure effects on a time-to-event endpoint using structural cumulative survival models.

Science.gov (United States)

Martinussen, Torben; Vansteelandt, Stijn; Tchetgen Tchetgen, Eric J; Zucker, David M

2017-12-01

The use of instrumental variables for estimating the effect of an exposure on an outcome is popular in econometrics, and increasingly so in epidemiology. This increasing popularity may be attributed to the natural occurrence of instrumental variables in observational studies that incorporate elements of randomization, either by design or by nature (e.g., random inheritance of genes). Instrumental variables estimation of exposure effects is well established for continuous outcomes and to some extent for binary outcomes. It is, however, largely lacking for time-to-event outcomes because of complications due to censoring and survivorship bias. In this article, we make a novel proposal under a class of structural cumulative survival models which parameterize time-varying effects of a point exposure directly on the scale of the survival function; these models are essentially equivalent with a semi-parametric variant of the instrumental variables additive hazards model. We propose a class of recursive instrumental variable estimators for these exposure effects, and derive their large sample properties along with inferential tools. We examine the performance of the proposed method in simulation studies and illustrate it in a Mendelian randomization study to evaluate the effect of diabetes on mortality using data from the Health and Retirement Study. We further use the proposed method to investigate potential benefit from breast cancer screening on subsequent breast cancer mortality based on the HIP-study. © 2017, The International Biometric Society.

Modification of bacterial cell survival by postirradiation hypoxia

Energy Technology Data Exchange (ETDEWEB)

Vexler, F B; Eidus, L Kh

1986-01-27

It is shown that postirradiation hypoxia affects the survival of E.coli. Hypoxic conditions immediately after a single-dose irradiation diminish cell survival in nutrient medium. Increasing time intervals between irradiation and hypoxia decrease the efficiency of the latter, while 1 h after irradiation hypoxia does not modify the survival of irradiated cells. These findings reveal that the mechanisms of action of postirradiation hypoxia on eu- and prokaryotic cells are similar.

The use of simple reparameterizations to improve the efficiency of Markov chain Monte Carlo estimation for multilevel models with applications to discrete time survival models.

Science.gov (United States)

Browne, William J; Steele, Fiona; Golalizadeh, Mousa; Green, Martin J

2009-06-01

We consider the application of Markov chain Monte Carlo (MCMC) estimation methods to random-effects models and in particular the family of discrete time survival models. Survival models can be used in many situations in the medical and social sciences and we illustrate their use through two examples that differ in terms of both substantive area and data structure. A multilevel discrete time survival analysis involves expanding the data set so that the model can be cast as a standard multilevel binary response model. For such models it has been shown that MCMC methods have advantages in terms of reducing estimate bias. However, the data expansion results in very large data sets for which MCMC estimation is often slow and can produce chains that exhibit poor mixing. Any way of improving the mixing will result in both speeding up the methods and more confidence in the estimates that are produced. The MCMC methodological literature is full of alternative algorithms designed to improve mixing of chains and we describe three reparameterization techniques that are easy to implement in available software. We consider two examples of multilevel survival analysis: incidence of mastitis in dairy cattle and contraceptive use dynamics in Indonesia. For each application we show where the reparameterization techniques can be used and assess their performance.

Multiple Imputation for Estimating the Risk of Developing Dementia and Its Impact on Survival

OpenAIRE

Yu, Binbing; Saczynski, Jane S.; Launer, Lenore J.

2010-01-01

Dementia, Alzheimer’s disease in particular, is one of the major causes of disability and decreased quality of life among the elderly and a leading obstacle to successful aging. Given the profound impact on public health, much research has focused on the age-specific risk of developing dementia and the impact on survival. Early work has discussed various methods of estimating age-specific incidence of dementia, among which the illness-death model is popular for modeling disease progression. I...

Lung cancer incidence and survival among HIV-infected and uninfected women and men.

Science.gov (United States)

Hessol, Nancy A; Martínez-Maza, Otoniel; Levine, Alexandra M; Morris, Alison; Margolick, Joseph B; Cohen, Mardge H; Jacobson, Lisa P; Seaberg, Eric C

2015-06-19

To determine the lung cancer incidence and survival time among HIV-infected and uninfected women and men. Two longitudinal studies of HIV infection in the United States. Data from 2549 women in the Women's Interagency HIV Study (WIHS) and 4274 men in the Multicenter AIDS Cohort Study (MACS), all with a history of cigarette smoking, were analyzed. Lung cancer incidence rates and incidence rate ratios were calculated using Poisson regression analyses. Survival time was assessed using Kaplan-Meier and Cox proportional-hazard analyses. Thirty-seven women and 23 men developed lung cancer (46 HIV-infected and 14 HIV-uninfected) during study follow-up. In multivariable analyses, the factors that were found to be independently associated with a higher lung cancer incidence rate ratios were older age, less education, 10 or more pack-years of smoking, and a prior diagnosis of AIDS pneumonia (vs. HIV-uninfected women). In an adjusted Cox model that allowed different hazard functions for each cohort, a history of injection drug use was associated with shorter survival, and a lung cancer diagnosis after 2001 was associated with longer survival. In an adjusted Cox model restricted to HIV-infected participants, nadir CD4 lymphocyte cell count less than 200 was associated with shorter survival time. Our data suggest that pulmonary damage and inflammation associated with HIV infection may be causative for the increased risk of lung cancer. Encouraging and assisting younger HIV-infected smokers to quit and to sustain cessation of smoking is imperative to reduce the lung cancer burden in this population.

Survival and development of Heliothis virescens (Lepidoptera: Noctuidae) larvae on isogenic tobacco lines with different levels of alkaloids.

Science.gov (United States)

Jackson, D Michael; Johnson, A W; Stephenson, M G

2002-12-01

Levels of pyridine alkaloids were measured in 18 tobacco, Nicotiana tabacum L., entries from three parental isolines ('NC 95', 'SC 58', and 'Coker 139'), grown at Tifton, GA, Florence, SC, and Oxford, NC, in 1991. Levels of alkaloids in bud leaves (first fully unfolded leaf below the apical leaf bud) were negatively correlated to natural infestation ratings of tobacco budworm larvae, Heliothis virescens (F.), 7 wk after transplanting. For artificially infested bud leaves at Oxford, there was a significant negative correlation between levels of total alkaloids and larval weights after 1 wk of feeding. In 1992, four entries from the 'NC 95' isoline were grown at Oxford, and samples for alkaloid analyses were taken every 2 wk at several leaf positions on each plant. During weeks 4, 8, 12, and 16, second instar tobacco budworms were caged on individual, intact leaves inside perforated plastic bags in the field. The survival and development of tobacco budworm larvae after 1 wk were negatively correlated with levels of alkaloids at the various leaf positions. Larvae survived better and grew faster on the bud leaves of each entry where alkaloid levels were lower than they did on leaves further down the stalk where alkaloid levels were higher. More larvae survived on the lower leaves of the low alkaloid lines than on the lower leaves of the high alkaloid lines. Even moderate increases in pyridine alkaloids had negative effects on tobacco budworm survival and development. Nicotine constituted >97% of the pyridine alkaloids in the 'NC95' isoline each year.

Socioeconomic development and girl child survival in rural North India: solution or problem?

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Krishnan, Anand; Dwivedi, Purva; Gupta, Vivek; Byass, Peter; Pandav, Chandrakant S; Ng, Nawi

2013-05-01

Socioeconomic development has been considered as a solution to the problem of sex differentials at birth and under-five mortality. This paper analyses longitudinal data from the Ballabgarh Health and Demographic Surveillance System (HDSS) site in north India to check its veracity. A cohort of children born between 1 January 2006 and 31 December 2011 at Ballabgarh HDSS were followed till death, emigration, 3 years of age or end of the study. Socioeconomic status (SES) was measured by caste, parental combined years of schooling and wealth index and divided into low, mid and high strata for each of them. Sex ratio at birth (SRB) was reported as the number of girls per 1000 boys. The Kaplan-Meier survival curves were drawn and a Cox Proportional HR of girls over boys was estimated. A total of 12 517 native born children (25 797 child years) were enrolled of which 710 died (death rate of 56.7/1000-live births and 27.5/1000 child-years. Socioeconomically advantaged children had significantly lower death rates. The SRB (10-16% lower) and neonatal death rate were consistently adverse for girls in the advantaged groups by all the three indicators of SES. The first month survival rates were better for girls in the lower SES categories (significant only in caste (HR 0.58; 0.37 to 0.91). High SES categories consistently showed adverse survival rates for girls (HR of 1.22 to 1.59). Better socioeconomic situation worsened the sex differentials, especially at birth. Therefore, specific interventions targeting gender issues are required, at least as a short-term measure.

Cell Survival Signaling in Neuroblastoma

Science.gov (United States)

Megison, Michael L.; Gillory, Lauren A.; Beierle, Elizabeth A.

2013-01-01

Neuroblastoma is the most common extracranial solid tumor of childhood and is responsible for over 15% of pediatric cancer deaths. Neuroblastoma tumorigenesis and malignant transformation is driven by overexpression and dominance of cell survival pathways and a lack of normal cellular senescence or apoptosis. Therefore, manipulation of cell survival pathways may decrease the malignant potential of these tumors and provide avenues for the development of novel therapeutics. This review focuses on several facets of cell survival pathways including protein kinases (PI3K, AKT, ALK, and FAK), transcription factors (NF-κB, MYCN and p53), and growth factors (IGF, EGF, PDGF, and VEGF). Modulation of each of these factors decreases the growth or otherwise hinders the malignant potential of neuroblastoma, and many therapeutics targeting these pathways are already in the clinical trial phase of development. Continued research and discovery of effective modulators of these pathways will revolutionize the treatment of neuroblastoma. PMID:22934706

Storage time of transfused blood and disease recurrence after colorectal cancer surgery

DEFF Research Database (Denmark)

Mynster, T; Nielsen, Hans Jørgen

2001-01-01

of the transfused blood. Therefore, we studied the relationship between blood storage time and the development of disease recurrence and long-term survival after colorectal cancer surgery. METHODS: Preoperative and postoperative data were prospectively recorded in 740 patients undergoing elective resection......BACKGROUND: Perioperative blood transfusion and subsequent development of postoperative infectious complications may lead to poor prognosis of patients with colorectal cancer. It has been suggested that the development of postoperative infectious complications may be related to the storage time...... transfused patients (P = 0.004). The survival of patients receiving blood exclusively stored blood stored > or = 21 days, survival was 3.7 years (P = 0.12). Among patients with curative resection (n = 532), the hazard ratio of disease recurrence was 1.5 (95...

Storage time of transfused blood and disease recurrence after colorectal cancer surgery

DEFF Research Database (Denmark)

Mynster, T; Nielsen, Hans Jørgen

2001-01-01

of the transfused blood. Therefore, we studied the relationship between blood storage time and the development of disease recurrence and long-term survival after colorectal cancer surgery. METHODS: Preoperative and postoperative data were prospectively recorded in 740 patients undergoing elective resection...... for primary colorectal cancer. None of the patients received preoperative or postoperative chemotherapy or radiation therapy. Endpoints were overall survival and disease recurrence in the subgroup of patients operated on with curative intention who also survived the first 30 days after operation. Storage......BACKGROUND: Perioperative blood transfusion and subsequent development of postoperative infectious complications may lead to poor prognosis of patients with colorectal cancer. It has been suggested that the development of postoperative infectious complications may be related to the storage time...

Improved survival in HIV treatment programs in Asia

Science.gov (United States)

De La Mata, Nicole L; Kumarasamy, Nagalingeswaran; Khol, Vohith; Ng, Oon Tek; Van Nguyen, Kinh; Merati, Tuti Parwati; Pham, Thuy Thanh; Lee, Man Po; Durier, Nicolas; Law, Matthew

2016-01-01

Background Antiretroviral treatment (ART) for HIV-positive patients has expanded rapidly in Asia over the last ten years. Our study aimed to describe the time trends and risk factors for overall survival in patients receiving first-line ART in Asia. Methods We included HIV-positive adult patients who initiated ART between 2003–2013 (n=16 546), from seven sites across six Asia-Pacific countries. Patient follow-up was to May 2014. We compared survival for each country and overall by time period of ART initiation using Kaplan-Meier curves. Factors associated with mortality were assessed using Cox regression, stratified by site. We also summarized first-line ART regimens, CD4 count at ART initiation, and CD4 and HIV viral load testing frequencies. Results There were 880 deaths observed over 54 532 person-years of follow-up, a crude rate of 1.61 (1.51, 1.72) per 100 person-years. Survival significantly improved in more recent years of ART initiation. The survival probabilities at 4 years follow-up for those initiating ART in 2003–05 was 92.1%, 2006–09 was 94.3% and 2010–2013 was 94.5% (pAsia have improved survival in more recent years of ART initiation. This is likely a consequence of improvements in treatment and, patient management and monitoring over time. PMID:26961354

Conditional survival of cancer patients: an Australian perspective

Directory of Open Access Journals (Sweden)

Yu Xue

2012-10-01

Full Text Available Abstract Background Estimated conditional survival for cancer patients diagnosed at different ages and disease stage provides important information for cancer patients and clinicians in planning follow-up, surveillance and ongoing management. Methods Using population-based cancer registry data for New South Wales Australia, we estimated conditional 5-year relative survival for 11 major cancers diagnosed 1972–2006 by time since diagnosis and age and stage at diagnosis. Results 193,182 cases were included, with the most common cancers being prostate (39,851, female breast (36,585 and colorectal (35,455. Five-year relative survival tended to increase with increasing years already survived and improvement was greatest for cancers with poor prognosis at diagnosis (lung or pancreas and for those with advanced stage or older age at diagnosis. After surviving 10 years, conditional 5-year survival was over 95% for 6 localised, 6 regional, 3 distant and 3 unknown stage cancers. For the remaining patient groups, conditional 5-year survival ranged from 74% (for distant stage bladder cancer to 94% (for 4 cancers at different stages, indicating that they continue to have excess mortality 10–15 years after diagnosis. Conclusion These data provide important information for cancer patients, based on age and stage at diagnosis, as they continue on their cancer journey. This information may also be used by clinicians as a tool to make more evidence-based decisions regarding follow-up, surveillance, or ongoing management according to patients' changing survival expectations over time.

Development and external validation of a risk-prediction model to predict 5-year overall survival in advanced larynx cancer

NARCIS (Netherlands)

Petersen, Japke F.; Stuiver, Martijn M.; Timmermans, Adriana J.; Chen, Amy; Zhang, Hongzhen; O'Neill, James P.; Deady, Sandra; Vander Poorten, Vincent; Meulemans, Jeroen; Wennerberg, Johan; Skroder, Carl; Day, Andrew T.; Koch, Wayne; van den Brekel, Michiel W. M.

2017-01-01

TNM-classification inadequately estimates patient-specific overall survival (OS). We aimed to improve this by developing a risk-prediction model for patients with advanced larynx cancer. Cohort study. We developed a risk prediction model to estimate the 5-year OS rate based on a cohort of 3,442

External validation and newly development of a nomogram to predict overall survival of abiraterone-treated, castration-resistant patients with metastatic prostate cancer

Directory of Open Access Journals (Sweden)

Yun-Jie Yang

2018-01-01

Full Text Available Abiraterone acetate is approved for the treatment of castration-resistant prostate cancer (CRPC; however, its effects vary. An accurate prediction model to identify patient groups that will benefit from abiraterone treatment is therefore urgently required. The Chi model exhibits a good profile for risk classification, although its utility for the chemotherapy-naive group is unclear. This study aimed to externally validate the Chi model and develop a new nomogram to predict overall survival (OS. We retrospectively analyzed a cohort of 110 patients. Patients were distributed among good-, intermediate-, and poor-risk groups, according to the Chi model. The good-, intermediate-, and poor-risk groups had a sample size of 59 (53.6%, 34 (30.9%, and 17 (15.5% in our dataset, and a median OS of 48.4, 29.1, and 10.5 months, respectively. The C-index of external validation of Chi model was 0.726. Univariate and multivariate analyses identified low hemoglobin concentrations (<110 g l−1, liver metastasis, and a short time interval from androgen deprivation therapy to abiraterone initiation (<36 months as predictors of OS. Accordingly, a new nomogram was developed with a C-index equal to 0.757 (95% CI, 0.678–0.836. In conclusion, the Chi model predicted the prognosis of abiraterone-treated, chemotherapy-naive patients with mCRPC, and we developed a new nomogram to predict the overall survival of this group of patients with less parameters.

Primary localization and tumor thickness as prognostic factors of survival in patients with mucosal melanoma.

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Tarun Mehra

Full Text Available Data on survival with mucosal melanoma and on prognostic factors of are scarce. It is still unclear if the disease course allows for mucosal melanoma to be treated as primary cutaneous melanoma or if differences in overall survival patterns require adapted therapeutic approaches. Furthermore, this investigation is the first to present 10-year survival rates for mucosal melanomas of different anatomical localizations.116 cases from Sep 10 1984 until Feb 15 2011 retrieved from the Comprehensive Cancer Center and of the Central Register of the German Dermatologic Society databases in Tübingen were included in our analysis. We recorded anatomical location and tumor thickness, and estimated overall survival at 2, 5 and 10 years and the mean overall survival time. Survival times were analyzed with the Kaplan-Meier method. The log-rank test was used to compare survival times by localizations and by T-stages.We found a median overall survival time of 80.9 months, with an overall 2-year survival of 71.7%, 5-year survival of 55.8% and 10-year survival of 38.3%. The 10-year survival rates for patients with T1, T2, T3 or T4 stage tumors were 100.0%, 77.9%, 66.3% and 10.6% respectively. 10-year survival of patients with melanomas of the vulva was 64.5% in comparison to 22.3% of patients with non-vulva mucosal melanomas.Survival times differed significantly between patients with melanomas of the vulva compared to the rest (p = 0.0006. It also depends on T-stage at the time of diagnosis (p < 0.0001.

Denosumab and Bone Metastasis–Free Survival in Men With Nonmetastatic Castration-Resistant Prostate Cancer: Exploratory Analyses by Baseline Prostate-Specific Antigen Doubling Time

Science.gov (United States)

Smith, Matthew R.; Saad, Fred; Oudard, Stephane; Shore, Neal; Fizazi, Karim; Sieber, Paul; Tombal, Bertrand; Damiao, Ronaldo; Marx, Gavin; Miller, Kurt; Van Veldhuizen, Peter; Morote, Juan; Ye, Zhishen; Dansey, Roger; Goessl, Carsten

2013-01-01

Purpose Denosumab, an anti–RANK ligand monoclonal antibody, significantly increases bone metastasis–free survival (BMFS; hazard ratio [HR], 0.85; P = .028) and delays time to first bone metastasis in men with nonmetastatic castration-resistant prostate cancer (CRPC) and baseline prostate-specific antigen (PSA) ≥ 8.0 ng/mL and/or PSA doubling time (PSADT) ≤ 10.0 months. To identify men at greatest risk for bone metastasis or death, we evaluated relationships between PSA and PSADT with BMFS in the placebo group and the efficacy and safety of denosumab in men with PSADT ≤ 10, ≤ 6, and ≤ 4 months. Patients and Methods A total of 1,432 men with nonmetastatic CRPC were randomly assigned 1:1 to monthly subcutaneous denosumab 120 mg or placebo. Enrollment began February 2006; primary analysis cutoff was July 2010, when approximately 660 men were anticipated to have developed bone metastases or died. Results In the placebo group, shorter BMFS was observed as PSADT decreased below 8 months. In analyses by shorter baseline PSADT, denosumab consistently increased BMFS by a median of 6.0, 7.2, and 7.5 months among men with PSADT ≤ 10 (HR, 0.84; P = .042), ≤ 6 (HR, 0.77; P = .006), and ≤ 4 months (HR, 0.71; P = .004), respectively. Denosumab also consistently increased time to bone metastasis by PSADT subset. No difference in survival was observed between treatment groups for the overall study population or PSADT subsets. Conclusion Patients with shorter PSADT are at greater risk for bone metastasis or death. Denosumab consistently improves BMFS in men with shorter PSADT and seems to have the greatest treatment effects in men at high risk for progression. PMID:24043751

Improved survival with an innovative approach to the treatment of severely burned patients: development of a burn treatment manual.

Science.gov (United States)

Morisada, S; Nosaka, N; Tsukahara, K; Ugawa, T; Sato, K; Ujike, Y

2015-09-30

The management of severely burned patients remains a major issue worldwide as indicated by the high incidence of permanent debilitating complications and poor survival rates. In April 2012, the Advanced Emergency & Critical Care Medical Center of the Okayama University Hospital began implementing guidelines for severely burned patients, distributed as a standard burn treatment manual. The protocol, developed in-house, was validated by comparing the outcomes of patients with severe extensive burns (SEB) treated before and after implementation of these new guidelines at this institution. The patients included in this study had a burn index (BI) ≥30 or a prognostic burn index (PBI = BI + patient's age) ≥100. The survival rate of the patients with BI ≥30 was 65.2% with the traditional treatment and 100% with the new guidelines. Likewise, the survival rate of the patients with PBI ≥100 was 61.1% with the traditional treatment compared to 100% with the new guidelines. Together, these data demonstrate that the new treatment guidelines dramatically improved the treatment outcome and survival of SEB patients.

Schinus terebinthifolius Leaf Extract Causes Midgut Damage, Interfering with Survival and Development of Aedes aegypti Larvae.

Science.gov (United States)

Procópio, Thamara Figueiredo; Fernandes, Kenner Morais; Pontual, Emmanuel Viana; Ximenes, Rafael Matos; de Oliveira, Aline Rafaella Cardoso; Souza, Carolina de Santana; Melo, Ana Maria Mendonça de Albuquerque; Navarro, Daniela Maria do Amaral Ferraz; Paiva, Patrícia Maria Guedes; Martins, Gustavo Ferreira; Napoleão, Thiago Henrique

2015-01-01

In this study, a leaf extract from Schinus terebinthifolius was evaluated for effects on survival, development, and midgut of A. aegypti fourth instar larvae (L4), as well as for toxic effect on Artemia salina. Leaf extract was obtained using 0.15 M NaCl and evaluated for phytochemical composition and lectin activity. Early L4 larvae were incubated with the extract (0.3-1.35%, w/v) for 8 days, in presence or absence of food. Polymeric proanthocyanidins, hydrolysable tannins, heterosid and aglycone flavonoids, cinnamic acid derivatives, traces of steroids, and lectin activity were detected in the extract, which killed the larvae at an LC50 of 0.62% (unfed larvae) and 1.03% (fed larvae). Further, the larvae incubated with the extract reacted by eliminating the gut content. No larvae reached the pupal stage in treatments at concentrations between 0.5% and 1.35%, while in the control (fed larvae), 61.7% of individuals emerged as adults. The extract (1.0%) promoted intense disorganization of larval midgut epithelium, including deformation and hypertrophy of cells, disruption of microvilli, and vacuolization of cytoplasms, affecting digestive, enteroendocrine, regenerative, and proliferating cells. In addition, cells with fragmented DNA were observed. Separation of extract components by solid phase extraction revealed that cinnamic acid derivatives and flavonoids are involved in larvicidal effect of the extract, being the first most efficient in a short time after larvae treatment. The lectin present in the extract was isolated, but did not show deleterious effects on larvae. The extract and cinnamic acid derivatives were toxic to A. salina nauplii, while the flavonoids showed low toxicity. S. terebinthifolius leaf extract caused damage to the midgut of A. aegypti larvae, interfering with survival and development. The larvicidal effect of the extract can be attributed to cinnamic acid derivatives and flavonoids. The data obtained using A. salina indicates that caution

Schinus terebinthifolius Leaf Extract Causes Midgut Damage, Interfering with Survival and Development of Aedes aegypti Larvae.

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Thamara Figueiredo Procópio

Full Text Available In this study, a leaf extract from Schinus terebinthifolius was evaluated for effects on survival, development, and midgut of A. aegypti fourth instar larvae (L4, as well as for toxic effect on Artemia salina. Leaf extract was obtained using 0.15 M NaCl and evaluated for phytochemical composition and lectin activity. Early L4 larvae were incubated with the extract (0.3-1.35%, w/v for 8 days, in presence or absence of food. Polymeric proanthocyanidins, hydrolysable tannins, heterosid and aglycone flavonoids, cinnamic acid derivatives, traces of steroids, and lectin activity were detected in the extract, which killed the larvae at an LC50 of 0.62% (unfed larvae and 1.03% (fed larvae. Further, the larvae incubated with the extract reacted by eliminating the gut content. No larvae reached the pupal stage in treatments at concentrations between 0.5% and 1.35%, while in the control (fed larvae, 61.7% of individuals emerged as adults. The extract (1.0% promoted intense disorganization of larval midgut epithelium, including deformation and hypertrophy of cells, disruption of microvilli, and vacuolization of cytoplasms, affecting digestive, enteroendocrine, regenerative, and proliferating cells. In addition, cells with fragmented DNA were observed. Separation of extract components by solid phase extraction revealed that cinnamic acid derivatives and flavonoids are involved in larvicidal effect of the extract, being the first most efficient in a short time after larvae treatment. The lectin present in the extract was isolated, but did not show deleterious effects on larvae. The extract and cinnamic acid derivatives were toxic to A. salina nauplii, while the flavonoids showed low toxicity. S. terebinthifolius leaf extract caused damage to the midgut of A. aegypti larvae, interfering with survival and development. The larvicidal effect of the extract can be attributed to cinnamic acid derivatives and flavonoids. The data obtained using A. salina indicates

Overall Survival After Whole-Brain Radiation Therapy for Intracerebral Metastases from Testicular Cancer.

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Rades, Dirk; Dziggel, Liesa; Veninga, Theo; Bajrovic, Amira; Schild, Steven E

2016-09-01

To identify predictors and develop a score for overall survival of patients with intracerebral metastasis from testicular cancer. Whole-brain radiation therapy program, age, Karnofsky performance score (KPS), number of intracerebral metastases, number of other metastatic sites and time between testicular cancer diagnosis and radiation therapy were analyzed for their association with overall survival in eight patients. KPS of 80-90% was significantly associated with better overall survival (p=0.006), one or no other metastatic sites showed a trend for a better outcome (p=0.10). The following scores were assigned: KPS 60-70%=0 points, KPS 80-90%=1 point, ≥2 other metastatic sites=0 points, 0-1 other metastatic sites=1 point. Two groups, with 0 and with 1-2 points, were formed. Overall survival rates were 33% vs. 100% at 6 months and 0% vs. 100% at 12 months (p=0.006), respectively. A simple instrument enabling physicians to judge the overall survival of patients with intracerebral metastasis from testicular cancer is provided. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Times of analgesic efficacy of two drugs in the treatment of patients with renal-ureteral colic compared by survival models

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Luis Reyes Velázquez

2015-01-01

Full Text Available Renourethral colic is a very painful clinical situation that requires a quick diagnosis and treatment. A study was done with patients who were administered two types of analgesics, and whose pain was measured through a visual analogue scale. Censored data results were obtained, considering the time when the pain disappeared as the random variable. Maximum likelihood and survival analysis give useful methods to estimate the distribution and parametric functions for this variable. This study will allow a more effective, timely, lower cost and suitable medical treatment for patients.

Development and internal validation of a prognostic model to predict recurrence free survival in patients with adult granulosa cell tumors of the ovary

NARCIS (Netherlands)

van Meurs, Hannah S.; Schuit, Ewoud; Horlings, Hugo M.; van der Velden, Jacobus; van Driel, Willemien J.; Mol, Ben Willem J.; Kenter, Gemma G.; Buist, Marrije R.

2014-01-01

Models to predict the probability of recurrence free survival exist for various types of malignancies, but a model for recurrence free survival in individuals with an adult granulosa cell tumor (GCT) of the ovary is lacking. We aimed to develop and internally validate such a prognostic model. We

PSA response to cabazitaxel is associated with improved progression-free survival in metastatic castration-resistant prostate cancer: the non-interventional QoLiTime study.

Science.gov (United States)

Hammerer, Peter; Al-Batran, Salah-Eddin; Windemuth-Kieselbach, Christine; Keller, Martin; Hofheinz, Ralf-Dieter

2018-03-01

To evaluate the association between prostate-specific antigen (PSA) response and progression-free and overall survival in men with metastatic castration-resistant prostate cancer (mCRPC) treated with cabazitaxel. Men with mCRPC receiving cabazitaxel (25 mg/m 2 , every 3 weeks) plus oral prednis(ol)one (10 mg/day) were enrolled in the non-interventional, prospective QoLiTime study. Main outcome measures were progression-free survival and overall survival, in all patients and in those who showed a ≥ 50 or a ≥ 30% decrease in PSA relative to baseline after four cycles of cabazitaxel, as well as quality-of-life parameters. Of the 527 men (median age 72 years), 266 received ≥ 4 cycles of cabazitaxel and had PSA response data. After four cycles, 34.6% of men achieved a PSA decrease ≥ 50% and 49.6% a decrease ≥ 30%. Median progression-free survival was 7.7 (95% CI 6.2, 9.5) months, and overall survival was 19.5 (95% CI 16.0, 30.9) months, corresponding to 1-year event rates of 39.4 and 78.8%, respectively. Median progression-free survival was longer in PSA responders versus non-responders (15.7 vs 5.5 months at 50% cut-off; 15.7 vs 5.3 months for 30% cut-off; both P PSA response after four cycles of cabazitaxel is associated with improved progression-free survival in men with mCRPC treated with cabazitaxel plus prednis(ol)one.

Comparison of cancer survival in New Zealand and Australia, 2006-2010.

Science.gov (United States)

Aye, Phyu S; Elwood, J Mark; Stevanovic, Vladimir

2014-12-19

Previous studies have shown substantially higher mortality rates from cancer in New Zealand compared to Australia, but these studies have not included data on patient survival. This study compares the survival of cancer patients diagnosed in 2006-10 in the whole populations of New Zealand and Australia. Identical period survival methods were used to calculate relative survival ratios for all cancers combined, and for 18 cancers each accounting for more than 50 deaths per year in New Zealand, from 1 to 10 years from diagnosis. Cancer survival was lower in New Zealand, with 5-year relative survival being 4.2% lower in women, and 3.8% lower in men for all cancers combined. Of 18 cancers, 14 showed lower survival in New Zealand; the exceptions, with similar survival in each country, being melanoma, myeloma, mesothelioma, and cervical cancer. For most cancers, the differences in survival were maximum at 1 year after diagnosis, becoming smaller later; however, for breast cancer, the survival difference increased with time after diagnosis. The lower survival in New Zealand, and the higher mortality rates shown earlier, suggest that further improvements in recognition, diagnosis, and treatment of cancer in New Zealand should be possible. As the survival differences are seen soon after diagnosis, issues of early management in primary care and time intervals to diagnosis and treatment may be particularly important.

Endogenous TSH levels at the time of {sup 131}I ablation do not influence ablation success, recurrence-free survival or differentiated thyroid cancer-related mortality

Energy Technology Data Exchange (ETDEWEB)

Vrachimis, Alexis; Riemann, Burkhard [University Hospital Muenster, Department of Nuclear Medicine, Muenster (Germany); Maeder, Uwe; Reiners, Christoph [University of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Verburg, Frederik A. [University of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); RWTH University Hospital Aachen, Department of Nuclear Medicine, Aachen (Germany)

2016-02-15

Based on a single older study it is established dogma that TSH levels should be ≥30 mU/l at the time of postoperative {sup 131}I ablation in differentiated thyroid cancer (DTC) patients. We sought to determine whether endogenous TSH levels, i.e. after levothyroxine withdrawal, at the time of ablation influence ablation success rates, recurrence-free survival and DTC-related mortality. A total of 1,873 patients without distant metastases referred for postoperative adjuvant {sup 131}I therapy were retrospectively included from 1991 onwards. Successful ablation was defined as stimulated Tg <1 μg/l. Age, gender and the presence of lymph node metastases were independent determinants of TSH levels at the time of ablation. TSH levels were not significantly related to ablation success rates (p = 0.34), recurrence-free survival (p = 0.29) or DTC -elated mortality (p = 0.82), but established risk factors such as T-stage, lymph node metastases and age were. Ablation was successful in 230 of 275 patients (83.6 %) with TSH <30 mU/l and in 1,359 of 1,598 patients (85.0 %) with TSH ≥30 mU/l. The difference was not significant (p = 0.55). Of the whole group of 1,873 patients, 21 had recurrent disease. There were no significant differences in recurrence rates between patients with TSH <30 mU/l and TSH ≥30 mU/l (p = 0.16). Ten of the 1,873 patients died of DTC. There were no significant differences in DTC-specific survival between patients with TSH <30 mU/l and TSH ≥30 mU/l (p = 0.53). The precise endogenous TSH levels at the time of {sup 131}I ablation are not related to the ablation success rates, recurrence free survival and DTC related mortality. The established dogma that TSH levels need to be ≥30 mU/l at the time of {sup 131}I ablation can be discarded. (orig.)

The LDsub(50/30) and the survival time in whole-body gamma-irradiated conventional and germfree Minnesota miniature piglets

International Nuclear Information System (INIS)

Mandel, L.; Travnicek, J.; Talafantova, M.; Zahradnickova, M.

1980-01-01

The median lethal exposure causing the death in 30 days after single whole-body gamma-irradiation (the LD 50/30) was found to be 2731 MBq (73.8 mC/kg) for conventional piglets, but 3226 MBq (87.2 mC/kg) for germ-free piglets both irradiated 14 days after birth. After lethal exposures, the survival time in germ-free piglets was prolonged for 7 days in comparison with conventional piglets. (author)

Development of TIME2 code

International Nuclear Information System (INIS)

1986-02-01

The paper reviews the progress on the development of a computer model TIME2, for modelling the long term evolution of shallow burial site environments for low- and intermediate-level radioactive waste disposal. The subject is discussed under the five topic headings: 1) background studies, including geomorphology, climate, human-induced effects, and seismicity, 2) development of the TIME2 code, 3) verification and testing, 4) documentation, and, 5) role of TIME2 in radiological risk assessment. (U.K.)

Conditional Melanoma Cancer Survival in the United States

Directory of Open Access Journals (Sweden)

Ray M. Merrill

2016-02-01

Full Text Available Beyond relative survival, which indicates the likelihood that patients will not die from causes associated with their cancer, conditional relative survival probabilities provide further useful prognostic information to cancer patients, tailored to the time already survived from diagnosis. This study presents conditional relative survival for melanoma patients in the United States, diagnosed during 2000–2008 and followed through 2012. Analyses are based on 62,803 male and 50,261 female cases in population-based cancer registries in the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute. Five-year relative survival estimates are presented for melanoma patients who have already survived one, two, three, four, or five years after the initial diagnosis. Five- and ten-year relative survival decreases with age, stage at diagnosis, and is lower among males, Blacks, and Hispanics. Five-year conditional relative survival improves with each year already survived. The potential for improvement in five-year conditional relative survival is greatest for older age, males, Blacks, Hispanics, and in later staged cases. For local disease, five-year conditional relative survival was significantly lower in ages greater than 65 years and in Blacks. It was significantly higher in females, non-Hispanics, and married individuals. Age had a greater inverse relationship with five-year survival in later staged disease. A similar result occurred for females and married individuals. In contrast, non-Hispanics had better five-year survival if diagnosed with local or regional disease, but not distant disease.

Nursing diagnoses in children with congenital heart disease: a survival analysis.

Science.gov (United States)

Martins da Silva, Viviane; Lopes, Marcos Venícios de Oliveira; Leite de Araujo, Thelma

2007-01-01

To analyze the relationship between nursing diagnoses and survival rates in children with congenital heart disease. A total of 270 observations were carried out in 45 children with congenital heart disease who were followed for 15 days. Differences in mean survival times were identified in children not more than 4 months of age with respect to the following diagnoses: impaired gas exchange, ineffective breathing pattern, activity intolerance, delayed growth and development, and decreased cardiac output. The main diagnoses are identified early in the hospitalization period and are conditions resulting from hemodynamic alterations and prescribed medical treatment. Congenital heart disease provokes serious hemodynamic alterations that generate human responses, which should be treated proactively.

The time development of QCD jets

International Nuclear Information System (INIS)

Caneschi, L.

1979-01-01

The time development of jets in perturbative QCD is studied. In spite of the fact that the total time for the jet to develop increases indefinitely with increasing energy, quark antiquark pairs remain unscreened only an infinitesimal time. (author)

An analysis of the survivability of sensor darts in impacts with trees.

Energy Technology Data Exchange (ETDEWEB)

Prentice, John K. (Sci-Tac, Inc., Boulder, CO.); Gardner, David Randall

2005-07-01

A methodology was developed for computing the probability that the sensor dart for the 'Near Real-Time Site Characterization for Assured HDBT Defeat' Grand-Challenge LDRD project will survive deployment over a forested region. The probability can be decomposed into three approximately independent probabilities that account for forest coverage, branch density and the physics of an impact between the dart and a tree branch. The probability that a dart survives an impact with a tree branch was determined from the deflection induced by the impact. If a dart that was deflected so that it impacted the ground at an angle of attack exceeding a user-specified, threshold value, the dart was assumed to not survive the impact with the branch; otherwise it was assumed to have survived. A computer code was developed for calculating dart angle of attack at impact with the ground and a Monte Carlo scheme was used to calculate the probability distribution of a sensor dart surviving an impact with a branch as a function of branch radius, length, and height from the ground. Both an early prototype design and the current dart design were used in these studies. As a general rule of thumb, it we observed that for reasonably generic trees and for a threshold angle of attack of 5{sup o} (which is conservative for dart survival), the probability of reaching the ground with an angle of attack less than the threshold is on the order of 30% for the prototype dart design and 60% for the current dart design, though these numbers should be treated with some caution.

Predictive model for survival in patients with gastric cancer.

Science.gov (United States)

Goshayeshi, Ladan; Hoseini, Benyamin; Yousefli, Zahra; Khooie, Alireza; Etminani, Kobra; Esmaeilzadeh, Abbas; Golabpour, Amin

2017-12-01

Gastric cancer is one of the most prevalent cancers in the world. Characterized by poor prognosis, it is a frequent cause of cancer in Iran. The aim of the study was to design a predictive model of survival time for patients suffering from gastric cancer. This was a historical cohort conducted between 2011 and 2016. Study population were 277 patients suffering from gastric cancer. Data were gathered from the Iranian Cancer Registry and the laboratory of Emam Reza Hospital in Mashhad, Iran. Patients or their relatives underwent interviews where it was needed. Missing values were imputed by data mining techniques. Fifteen factors were analyzed. Survival was addressed as a dependent variable. Then, the predictive model was designed by combining both genetic algorithm and logistic regression. Matlab 2014 software was used to combine them. Of the 277 patients, only survival of 80 patients was available whose data were used for designing the predictive model. Mean ?SD of missing values for each patient was 4.43?.41 combined predictive model achieved 72.57% accuracy. Sex, birth year, age at diagnosis time, age at diagnosis time of patients' family, family history of gastric cancer, and family history of other gastrointestinal cancers were six parameters associated with patient survival. The study revealed that imputing missing values by data mining techniques have a good accuracy. And it also revealed six parameters extracted by genetic algorithm effect on the survival of patients with gastric cancer. Our combined predictive model, with a good accuracy, is appropriate to forecast the survival of patients suffering from Gastric cancer. So, we suggest policy makers and specialists to apply it for prediction of patients' survival.

Design and Analysis of Salmonid Tagging Studies in the Columbia Basin : Evaluating Wetland Restoration Projects in the Columbia River Estuary using Hydroacoustic Telemetry Arrays to Estimate Movement, Survival, and Residence Times of Juvenile Salmonids, Volume XXII (22).

Energy Technology Data Exchange (ETDEWEB)

Perry, Russell W.; Skalski, John R.

2008-08-01

Wetlands in the Columbia River estuary are actively being restored by reconnecting these habitats to the estuary, making more wetland habitats available to rearing and migrating juvenile salmon. Concurrently, thousands of acoustically tagged juvenile salmonids are released into the Columbia River to estimate their survival as they migrate through the estuary. Here, we develop a release-recapture model that makes use of these tagged fish to measure the success of wetland restoration projects in terms of their contribution to populations of juvenile salmon. Specifically, our model estimates the fraction of the population that enter the wetland, survival within the wetland, and the mean residence time of fish within the wetland. Furthermore, survival in mainstem Columbia River downstream of the wetland can be compared between fish that remained the mainstem and entered the wetland. These conditional survival estimates provide a means of testing whether the wetland improves the subsequent survival of juvenile salmon by fostering growth or improving their condition. Implementing such a study requires little additional cost because it takes advantage of fish already released to estimate survival through the estuary. Thus, such a study extracts the maximum information at minimum cost from research projects that typically cost millions of dollars annually.

Integrative analysis of survival-associated gene sets in breast cancer.

Science.gov (United States)

Varn, Frederick S; Ung, Matthew H; Lou, Shao Ke; Cheng, Chao

2015-03-12

Patient gene expression information has recently become a clinical feature used to evaluate breast cancer prognosis. The emergence of prognostic gene sets that take advantage of these data has led to a rich library of information that can be used to characterize the molecular nature of a patient's cancer. Identifying robust gene sets that are consistently predictive of a patient's clinical outcome has become one of the main challenges in the field. We inputted our previously established BASE algorithm with patient gene expression data and gene sets from MSigDB to develop the gene set activity score (GSAS), a metric that quantitatively assesses a gene set's activity level in a given patient. We utilized this metric, along with patient time-to-event data, to perform survival analyses to identify the gene sets that were significantly correlated with patient survival. We then performed cross-dataset analyses to identify robust prognostic gene sets and to classify patients by metastasis status. Additionally, we created a gene set network based on component gene overlap to explore the relationship between gene sets derived from MSigDB. We developed a novel gene set based on this network's topology and applied the GSAS metric to characterize its role in patient survival. Using the GSAS metric, we identified 120 gene sets that were significantly associated with patient survival in all datasets tested. The gene overlap network analysis yielded a novel gene set enriched in genes shared by the robustly predictive gene sets. This gene set was highly correlated to patient survival when used alone. Most interestingly, removal of the genes in this gene set from the gene pool on MSigDB resulted in a large reduction in the number of predictive gene sets, suggesting a prominent role for these genes in breast cancer progression. The GSAS metric provided a useful medium by which we systematically investigated how gene sets from MSigDB relate to breast cancer patient survival. We used

Cancer survival for Aboriginal and Torres Strait Islander Australians: a national study of survival rates and excess mortality.

Science.gov (United States)

Condon, John R; Zhang, Xiaohua; Baade, Peter; Griffiths, Kalinda; Cunningham, Joan; Roder, David M; Coory, Michael; Jelfs, Paul L; Threlfall, Tim

2014-01-31

National cancer survival statistics are available for the total Australian population but not Indigenous Australians, although their cancer mortality rates are known to be higher than those of other Australians. We aimed to validate analysis methods and report cancer survival rates for Indigenous Australians as the basis for regular national reporting. We used national cancer registrations data to calculate all-cancer and site-specific relative survival for Indigenous Australians (compared with non-Indigenous Australians) diagnosed in 2001-2005. Because of limited availability of Indigenous life tables, we validated and used cause-specific survival (rather than relative survival) for proportional hazards regression to analyze time trends and regional variation in all-cancer survival between 1991 and 2005. Survival was lower for Indigenous than non-Indigenous Australians for all cancers combined and for many cancer sites. The excess mortality of Indigenous people with cancer was restricted to the first three years after diagnosis, and greatest in the first year. Survival was lower for rural and remote than urban residents; this disparity was much greater for Indigenous people. Survival improved between 1991 and 2005 for non-Indigenous people (mortality decreased by 28%), but to a much lesser extent for Indigenous people (11%) and only for those in remote areas; cancer survival did not improve for urban Indigenous residents. Cancer survival is lower for Indigenous than other Australians, for all cancers combined and many individual cancer sites, although more accurate recording of Indigenous status by cancer registers is required before the extent of this disadvantage can be known with certainty. Cancer care for Indigenous Australians needs to be considerably improved; cancer diagnosis, treatment, and support services need to be redesigned specifically to be accessible and acceptable to Indigenous people.

Survival after stereotactic biopsy of malignant gliomas

International Nuclear Information System (INIS)

Coffey, R.J.; Lunsford, L.D.; Taylor, F.H.

1988-01-01

For many patients with malignant gliomas in inaccessible or functionally important locations, stereotactic biopsy followed by radiation therapy (RT) may be a more appropriate initial treatment than craniotomy and tumor resection. We studied the long term survival in 91 consecutive patients with malignant gliomas diagnosed by stereotactic biopsy: 64 had glioblastoma multiforme (GBM) and 27 had anaplastic astrocytoma (AA). Sixty-four per cent of the GBMs and 33% of the AAs involved deep or midline cerebral structures. The treatment prescribed after biopsy, the tumor location, the histological findings, and the patient's age at presentation (for AAs) were statistically important factors determining patient survival. If adequate RT (tumor dose of 5000 to 6000 cGy) was not prescribed, the median survival was less than or equal to 11 weeks regardless of tumor histology or location. The median survival for patients with deep or midline tumors who completed RT was similar in AA (19.4 weeks) and GBM (27 weeks) cases. Histology was an important predictor of survival only for patients with adequately treated lobar tumors. The median survival in lobar GBM patients who completed RT was 46.9 weeks, and that in lobar AA patients who completed RT was 129 weeks. Cytoreductive surgery had no statistically significant effect on survival. Among the clinical factors examined, age of less than 40 years at presentation was associated with prolonged survival only in AA patients. Constellations of clinical features, tumor location, histological diagnosis, and treatment prescribed were related to survival time

Partitioning of excess mortality in population-based cancer patient survival studies using flexible parametric survival models

Directory of Open Access Journals (Sweden)

Eloranta Sandra

2012-06-01

Full Text Available Abstract Background Relative survival is commonly used for studying survival of cancer patients as it captures both the direct and indirect contribution of a cancer diagnosis on mortality by comparing the observed survival of the patients to the expected survival in a comparable cancer-free population. However, existing methods do not allow estimation of the impact of isolated conditions (e.g., excess cardiovascular mortality on the total excess mortality. For this purpose we extend flexible parametric survival models for relative survival, which use restricted cubic splines for the baseline cumulative excess hazard and for any time-dependent effects. Methods In the extended model we partition the excess mortality associated with a diagnosis of cancer through estimating a separate baseline excess hazard function for the outcomes under investigation. This is done by incorporating mutually exclusive background mortality rates, stratified by the underlying causes of death reported in the Swedish population, and by introducing cause of death as a time-dependent effect in the extended model. This approach thereby enables modeling of temporal trends in e.g., excess cardiovascular mortality and remaining cancer excess mortality simultaneously. Furthermore, we illustrate how the results from the proposed model can be used to derive crude probabilities of death due to the component parts, i.e., probabilities estimated in the presence of competing causes of death. Results The method is illustrated with examples where the total excess mortality experienced by patients diagnosed with breast cancer is partitioned into excess cardiovascular mortality and remaining cancer excess mortality. Conclusions The proposed method can be used to simultaneously study disease patterns and temporal trends for various causes of cancer-consequent deaths. Such information should be of interest for patients and clinicians as one way of improving prognosis after cancer is

Effect of a long-term high-protein diet on survival, obesity development, and gut microbiota in mice

NARCIS (Netherlands)

Kiilerich, Pia; Myrmel, Lene Secher; Fjære, Even; Hao, Qin; Hugenholtz, Floor; Sonne, Si Brask; Derrien, Muriel; Pedersen, Lone Møller; Petersen, Rasmus Koefoed; Mortensen, Alicja; Licht, Tine Rask; Rømer, Maria Unni; Vogel, Ulla Birgitte; Waagbø, Linn Jeanette; Giallourou, Natasa; Feng, Qiang; Xiao, Liang; Liu, Chuan; Liaset, Bjørn; Kleerebezem, Michiel; Wang, Jun; Madsen, Lise; Kristiansen, Karsten

2016-01-01

Female C57BL/6J mice were fed a regular low-fat diet or high-fat diets combined with either high or low protein-to-sucrose ratios during their entire lifespan to examine the long-term effects on obesity development, gut microbiota, and survival. Intake of a high-fat diet with a low

A comparative study of generalized linear mixed modelling and artificial neural network approach for the joint modelling of survival and incidence of Dengue patients in Sri Lanka

Science.gov (United States)

Hapugoda, J. C.; Sooriyarachchi, M. R.

2017-09-01

Survival time of patients with a disease and the incidence of that particular disease (count) is frequently observed in medical studies with the data of a clustered nature. In many cases, though, the survival times and the count can be correlated in a way that, diseases that occur rarely could have shorter survival times or vice versa. Due to this fact, joint modelling of these two variables will provide interesting and certainly improved results than modelling these separately. Authors have previously proposed a methodology using Generalized Linear Mixed Models (GLMM) by joining the Discrete Time Hazard model with the Poisson Regression model to jointly model survival and count model. As Aritificial Neural Network (ANN) has become a most powerful computational tool to model complex non-linear systems, it was proposed to develop a new joint model of survival and count of Dengue patients of Sri Lanka by using that approach. Thus, the objective of this study is to develop a model using ANN approach and compare the results with the previously developed GLMM model. As the response variables are continuous in nature, Generalized Regression Neural Network (GRNN) approach was adopted to model the data. To compare the model fit, measures such as root mean square error (RMSE), absolute mean error (AME) and correlation coefficient (R) were used. The measures indicate the GRNN model fits the data better than the GLMM model.

Formulating accident occurrence as a survival process.

Science.gov (United States)

Chang, H L; Jovanis, P P

1990-10-01

A conceptual framework for accident occurrence is developed based on the principle of the driver as an information processor. The framework underlies the development of a modeling approach that is consistent with the definition of exposure to risk as a repeated trial. Survival theory is proposed as a statistical technique that is consistent with the conceptual structure and allows the exploration of a wide range of factors that contribute to highway operating risk. This survival model of accident occurrence is developed at a disaggregate level, allowing safety researchers to broaden the scope of studies which may be limited by the use of traditional aggregate approaches. An application of the approach to motor carrier safety is discussed as are potential applications to a variety of transportation industries. Lastly, a typology of highway safety research methodologies is developed to compare the properties of four safety methodologies: laboratory experiments, on-the-road studies, multidisciplinary accident investigations, and correlational studies. The survival theory formulation has a mathematical structure that is compatible with each safety methodology, so it may facilitate the integration of findings across methodologies.

Effect of a long-term high-protein diet on survival, obesity development, and gut microbiota in mice

NARCIS (Netherlands)

Kiilerich, Pia; Myrmel, Lene Secher; Fjære, Even; Hao, Qin; Hugenholtz, Floor; Sonne, Si Brask; Derrien, Muriel; Pedersen, Lone Møller; Petersen, Rasmus Koefoed; Mortensen, Alicja; Licht, Tine Rask; Rømer, Maria Unni; Vogel, Ulla Birgitte; Waagbø, Linn Jeanette; Giallourou, Natasa; Feng, Qiang; Xiao, Liang; Liu, Chuan; Liaset, Bjørn; Kleerebezem, Michiel; Wang, Jun; Madsen, Lise; Kristiansen, Karsten

2016-01-01

Female C57BL/6J mice were fed a regular low-fat diet or high-fat diets combined with either high or low protein-to-sucrose ratios during their entire lifespan to examine the long-term effects on obesity development, gut microbiota, and survival. Intake of a high-fat diet with a low protein/sucrose

Accelerated failure time regression for backward recurrence times and current durations

DEFF Research Database (Denmark)

Keiding, N; Fine, J P; Hansen, O H

2011-01-01

Backward recurrence times in stationary renewal processes and current durations in dynamic populations observed at a cross-section may yield estimates of underlying interarrival times or survival distributions under suitable stationarity assumptions. Regression models have been proposed for these......Backward recurrence times in stationary renewal processes and current durations in dynamic populations observed at a cross-section may yield estimates of underlying interarrival times or survival distributions under suitable stationarity assumptions. Regression models have been proposed...... for these situations, but accelerated failure time models have the particularly attractive feature that they are preserved when going from the backward recurrence times to the underlying survival distribution of interest. This simple fact has recently been noticed in a sociological context and is here illustrated...... by a study of current duration of time to pregnancy...

Development of a predictive model for 6 month survival in patients with venous thromboembolism and solid malignancy requiring IVC filter placement.

Science.gov (United States)

Huang, Steven Y; Odisio, Bruno C; Sabir, Sharjeel H; Ensor, Joe E; Niekamp, Andrew S; Huynh, Tam T; Kroll, Michael; Gupta, Sanjay

2017-07-01

Our purpose was to develop a predictive model for short-term survival (i.e. filter placement in patients with venous thromboembolism (VTE) and solid malignancy. Clinical and laboratory parameters were retrospectively reviewed for patients with solid malignancy who received a filter between January 2009 and December 2011 at a tertiary care cancer center. Multivariate Cox proportional hazards modeling was used to assess variables associated with 6 month survival following filter placement in patients with VTE and solid malignancy. Significant variables were used to generate a predictive model. 397 patients with solid malignancy received a filter during the study period. Three variables were associated with 6 month survival: (1) serum albumin [hazard ratio (HR) 0.496, P filter placement can be predicted from three patient variables. Our predictive model could be used to help physicians decide whether a permanent or retrievable filter may be more appropriate as well as to assess the risks and benefits for filter retrieval within the context of survival longevity in patients with cancer.

The survival of Coxiella burnetii in soils

Science.gov (United States)

Evstigneeva, A. S.; Ul'Yanova, T. Yu.; Tarasevich, I. V.

2007-05-01

Coxiella burnetii is a pathogen of Q-fever—a widespread zoonosis. The effective adaptation of C. burnetii to intracellular existence is in contrast with its ability to survive in the environment outside the host cells and its resistance to chemical and physical agents. Its mechanism of survival remains unknown. However, its survival appears to be related to the developmental cycle of the microorganism itself, i.e., to the formation of its dormant forms. The survival of Coxiella burnetii was studied for the first time. The pathogenic microorganism was inoculated into different types of soil and cultivated under different temperatures. The survival of the pathogen was verified using a model with laboratory animals (mice). Viable C. burnetii were found in the soil even 20 days after their inoculation. The relationship between the organic carbon content in the soils and the survival of C. burnetii was revealed. Thus, the results obtained were the first to demonstrate that the soil may serve as a reservoir for the preservation and further spreading of the Q-fever pathogen in the environment, on the one hand, and reduce the risk of epidemics, on the other.

The Timing of Sleep in Depression : Theoretical Considerations

NARCIS (Netherlands)

Beersma, Domien G.M.; Daan, Serge; Hoofdakker, Rutger H. van den

1985-01-01

Endogenously depressed subjects frequently show severe sleep problems. In this article sleep time in depression is discussed in relation to a recently developed model for sleep timing in healthy subjects. In terms of the model, two parameter sets survive a qualitative comparison with the empirical

Effects of salinity on egg and fecal pellet production, development and survival, adult sex ratio and total life span in the calanoid copepod, Acartia tonsa: a laboratory study

Science.gov (United States)

Shayegan, Majid; Esmaeili Fereidouni, Abolghasem; Agh, Naser; Jani Khalili, Khosrow

2016-07-01

The effects of salinity on the copepod, Acartia tonsa in terms of daily egg production rate (EPR), hatching success, fecal pellet production rate (FPR), naupliar development time and survival, sex ratio, and total life span were determined in laboratory conditions through three experiments. In experiment 1, EPR, hatching success, and FPR of individual females were monitored at salinities of 13, 20, 35 and 45 during short-periods (seven consecutive days). Results show EPR was affected by salinity with the highest outputs recorded at 20 and 35, respectively, which were considerably higher than those at 13 and 45. Mean FPR was also higher in 35 and 20. In experiment 2, the same parameters were evaluated over total life span of females (long-term study). The best EPR and FPR were observed in 35, which was statistically higher than at 13 and 20. In experiment 3, survival rates of early nauplii until adult stage were lowest at a salinity of 13. The development time increased with increasing of salinity. Female percentage clearly decreased with increasing salinity. Higher female percentages (56.7% and 52.2%, respectively) were significantly observed at two salinities of 13 and 20 compared to that at 35 (25%). Total longevity of females was not affected by salinity increment. Based on our results, for mass culture we recommend that a salinity of 35 be adopted due to higher reproductive performances, better feeding, and faster development of A. tonsa.

Stereotactic Radiosurgery in the Management of Brain Metastases: An Institutional Retrospective Analysis of Survival

International Nuclear Information System (INIS)

Frazier, James L.; Batra, Sachin; Kapor, Sumit; Vellimana, Ananth; Gandhi, Rahul; Carson, Kathryn A.; Shokek, Ori; Lim, Michael; Kleinberg, Lawrence; Rigamonti, Daniele

2010-01-01

Purpose: The objective of this study was to report our experience with stereotactic radiosurgery performed with the Gamma Knife (GK) in the treatment of patients with brain metastases and to compare survival for those treated with radiosurgery alone with survival for those treated with radiosurgery and whole-brain radiotherapy. Methods and Materials: Prospectively collected demographic and clinical characteristics and treatment and survival data on 237 patients with intracranial metastases who underwent radiosurgery with the GK between 2003 and 2007 were reviewed. Kaplan-Meier and Cox proportional hazards regression analyses were used to compare survival by demographic and clinical characteristics and treatment. Results: The mean age of the patient population was 56 years. The most common tumor histologies were non-small-cell lung carcinoma (34.2%) and breast cancer (13.9%). The median overall survival time was 8.5 months from the time of treatment. The median survival times for patients with one, two/three, and four or more brain metastases were 8.5, 9.4, and 6.7 months, respectively. Patients aged 65 years or greater and those aged less than 65 years had median survival times of 7.8 and 9 months, respectively (p = 0.008). The Karnofsky Performance Score (KPS) at the time of treatment was a significant predictor of survival: those patients with a KPS of 70 or less had a median survival of 2.9 months compared with 10.3 months (p = 0.034) for those with a KPS of 80 or greater. There was no statistically significant difference in survival between patients treated with radiosurgery alone and those treated with radiosurgery plus whole-brain radiotherapy. Conclusions: Radiosurgery with the GK is an efficacious treatment modality for brain metastases. A KPS greater than 70, histology of breast cancer, smaller tumor volume, and age less than 65 years were associated with a longer median survival in our study.

Mammalian target of rapamycin is essential for cardiomyocyte survival and heart development in mice

International Nuclear Information System (INIS)

Zhang, Pengpeng; Shan, Tizhong; Liang, Xinrong; Deng, Changyan; Kuang, Shihuan

2014-01-01

Highlights: • mTOR is a critical regulator of many biological processes yet its function in heart is not well understood. • MCK-Cre/Mtor flox/flox mice were established to delete Mtor in cardiomyocytes. • The mTOR-mKO mice developed normally but die prematurely within 5 weeks after birth due to heart disease. • The mTOR-mKO mice had dilated myocardium and increased cell death. • mTOR-mKO hearts had reduced expression of metabolic genes and activation of mTOR target proteins. - Abstract: Mammalian target of rapamycin (mTOR) is a critical regulator of protein synthesis, cell proliferation and energy metabolism. As constitutive knockout of Mtor leads to embryonic lethality, the in vivo function of mTOR in perinatal development and postnatal growth of heart is not well defined. In this study, we established a muscle-specific mTOR conditional knockout mouse model (mTOR-mKO) by crossing MCK-Cre and Mtor flox/flox mice. Although the mTOR-mKO mice survived embryonic and perinatal development, they exhibited severe postnatal growth retardation, cardiac muscle pathology and premature death. At the cellular level, the cardiac muscle of mTOR-mKO mice had fewer cardiomyocytes due to apoptosis and necrosis, leading to dilated cardiomyopathy. At the molecular level, the cardiac muscle of mTOR-mKO mice expressed lower levels of fatty acid oxidation and glycolysis related genes compared to the WT littermates. In addition, the mTOR-mKO cardiac muscle had reduced Myh6 but elevated Myh7 expression, indicating cardiac muscle degeneration. Furthermore, deletion of Mtor dramatically decreased the phosphorylation of S6 and AKT, two key targets downstream of mTORC1 and mTORC2 mediating the normal function of mTOR. These results demonstrate that mTOR is essential for cardiomyocyte survival and cardiac muscle function

Social determinants of health and 5-year survival of colorectal cancer.

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Heidarnia, Mohammad Ali; Monfared, Esmat Davoudi; Akbari, Mohammad Esmail; Yavari, Parvin; Amanpour, Farzaneh; Mohseni, Maryam

2013-01-01

Early in the 21st century, cancers are the second cause of death worldwide. Colon cancer is third most common cancer and one of the few amenable to early diagnosis and treatment. Evaluation of factors affecting this cancer is important to increase survival time. Some of these factors affecting all diseases including cancer are social determinants of health. According to the importance of this disease and relation with these factors, this study was conducted to assess the relationship between social determinants of health and colon cancer survival. This was a cross-sectional, descriptive study for patients with colon cancer registered in the Cancer Research Center of Shahid Beheshti University of Medical Science, from April 2005 to November 2006, performed using questionnaires filled by telephone interview with patients (if patients had died, with family members). Data was analyzed with SPSS software (version 19) for descriptive analysis and STATA software for survival analysis including log rank test and three step Cox Proportional Hazard regression. Five hundred fifty nine patients with ages ranging from 23 to 88 years with mean ± standard deviation of 63 ± 11.8 years were included in the study. The five year survival was 68.3%( 387 patients were alive and 172 patients were dead by the end of the study). The Cox proportional hazard regression showed 5-year survival was related to age (HR=0.53, p=0.042 for>50 years versusmanual versus non manual jobs), region of residency (HR=3.49, p=0.018 for west versus south regions), parents in childhood (HR=2.87, p=0.012 for having both parents versus not having), anatomical cancer location (HR=2.16, psurvival of colon cancer and it may be better to consider these factors in addition to developing cancer treatment and to focus on these determinants of health in long-time planning.

Effects of Oral Administration of Fucoidan Extracted from Cladosiphon okamuranus on Tumor Growth and Survival Time in a Tumor-Bearing Mouse Model

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Yoshiharu Okamoto

2012-10-01

Full Text Available We evaluated the anti-tumor activities of the oral administration of fucoidan extracted from Cladosiphon okamuranus using a tumor (colon 26-bearing mouse model. The materials used included low-molecular-weight fucoidan (LMWF: 6.5–40 kDa, intermediate-molecular-weight fucoidan (IMWF: 110–138 kDa and high-molecular-weight fucoidan (HMWF: 300–330 kDa. The IMWF group showed significantly suppressed tumor growth. The LMWF and HMWF groups showed significantly increased survival times compared with that observed in the control group (mice fed a fucoidan-free diet. The median survival times in the control, LMWF, IMWF and HMWF groups were 23, 46, 40 and 43 days, respectively. It was also found that oral administration of fucoidan increased the population of natural killer cells in the spleen. Furthermore, from the results of the experiment using Myd-88 knockout mice, it was found that these effects are related to gut immunity. These results suggest that fucoidan is a candidate anti-tumor functional food.

Succession and survival in psychotherapy organizations.

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Khaleelee, Olya

2008-11-01

This paper examines the world of psychotherapy by applying a systemic and psychodynamic understanding of the family business as a way of understanding the dilemmas and challenges of leadership succession. Oedipal factors are explored as an important theme within the succession process. This exploration is set within the context of what function psychotherapy has performed in society over the last thirty years. The hypothesis is that the first generation of leaders aimed to provide containment for the individual citizen at a time of failed dependency in society. The suggestion is that this gave way to the primary task for the second generation, which has been to focus on the therapist in training. The challenge for the third generation is to develop a meaningful role for psychotherapy today and to ensure survival at a time when other shorter therapies such as CBT are gaining ascendancy over longer term psychoanalytic psychotherapy.

Economic Competition, Sustainability, and Survival Endurance: The Extinction of the Dodo, the Easter Island Case, and the Tragedy of the Commons Effect

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Moreira, Pedro

2012-01-01

A fast developing industry worldwide, tourism demands a monumental extent of resources, and at times devastates and condemns the very own environments that are fundamental to the economic survival of organizations and the sustainability of travel destinations. The purpose of the study is to link three established scientific themes on survival and…

Factors associated with survival of epiploic foramen entrapment colic: a multicentre, international study.

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Archer, D C; Pinchbeck, G L; Proudman, C J

2011-08-01

Epiploic foramen entrapment (EFE) has been associated with reduced post operative survival compared to other types of colic but specific factors associated with reduced long-term survival of these cases have not been evaluated in a large number of horses using survival analysis. To describe post operative survival of EFE cases and to identify factors associated with long-term survival. A prospective, multicentre, international study was conducted using clinical data and long-term follow-up information for 126 horses diagnosed with EFE during exploratory laparotomy at 15 clinics in the UK, Ireland and USA. Descriptive data were generated and survival analysis performed to identify factors associated with reduced post operative survival. For the EFE cohort that recovered following anaesthesia, survival to hospital discharge was 78.5%. Survival to 1 and 2 years post operatively was 50.6 and 34.3%, respectively. The median survival time of EFE cases undergoing surgery was 397 days. Increased packed cell volume (PCV) and increased length of small intestine (SI) resected were significantly associated with increased likelihood of mortality when multivariable analysis of pre- and intraoperative variables were analysed. When all pre-, intra- and post operative variables were analysed separately, only horses that developed post operative ileus (POI) were shown to be at increased likelihood of mortality. Increased PCV, increased length of SI resected and POI are all associated with increased likelihood of mortality of EFE cases. This emphasises the importance of early diagnosis and treatment and the need for improved strategies in the management of POI in order to reduce post operative mortality in these cases. The present study provides evidence-based information to clinicians and owners of horses undergoing surgery for EFE about long-term survival. These results are applicable to university and large private clinics over a wide geographical area. © 2011 EVJ Ltd.

Dietary proteins extend the survival of salmonella dublin in a gastric Acid environment

DEFF Research Database (Denmark)

Birk, Tina; Kristensen, Kim; Harboe, Anne

2012-01-01

The pH of the human stomach is dynamic and changes over time, depending on the composition of the food ingested and a number of host-related factors such as age. To evaluate the number of bacteria surviving the gastric acid barrier, we have developed a simple gastric acid model, in which we...... mimicked the dynamic pH changes in the human stomach. In the present study, model gastric fluid was set up to imitate pH dynamics in the stomachs of young and elderly people after ingestion of a standard meal. To model a serious foodborne pathogen, we followed the survival of Salmonella enterica serotype...

Survival in 76 cats with epilepsy of unknown cause: a retrospective study.

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Szelecsenyi, Arlette Cornelia; Giger, Urs; Golini, Lorenzo; Mothersill, Ian; Torgerson, Paul R; Steffen, Frank

2017-11-01

Survival of cats with epilepsy of unknown cause (EUC) has not been reported. Seizure semiology and its relationship to treatment outcome and survival was studied in a population of 76 cats. A questionnaire for seizure semiology was developed based on experimental data. Seizure semiology was characterised by owner interviews at least one year after discharge. Seizures were classified as (1) primary generalised and (2) focal without and (3) with secondary generalisation. Median age at seizure onset was four (range 0.3-18) years. One-third of cats with EUC presented with primary generalised seizures and 78 per cent of those with initially focal seizures progressed to secondary generalised seizures. Clinical signs of generalised seizures included sudden onset of loss of consciousness and tonic-clonic seizures, while cats with focal seizures had unilateral signs. Antiepileptic drug (AED) therapy was initiated in 62 cats. Complete remission rate was 42 per cent and the median survival time was 3.2 (range 1-11) years with or without AED, and 91 per cent were still alive at the time of interview. Neither semiology nor seizure type predicted survival, response to treatment and outcome in cats with EUC. A seizure-free status of more than 12 months was observed in 79 per cent of cats without AED. © British Veterinary Association (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Trends in Testicular Cancer Survival: A Large Population-based Analysis.

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Sui, Wilson; Morrow, David C; Bermejo, Carlos E; Hellenthal, Nicholas J

2015-06-01

To determine whether discrepancies in testicular cancer outcomes between Caucasians and non-Caucasians are changing over time. Although testicular cancer is more common in Caucasians, studies have shown that other races have worse outcomes. Using the Surveillance, Epidemiology, and End Results registry, we identified 29,803 patients diagnosed with histologically confirmed testicular cancer between 1983 and 2011. Of these, 12,650 patients (42%) had 10-year follow-up data. We stratified the patients by age group, stage, race, and year of diagnosis and assessed 10-year overall and cancer-specific survival in each cohort. Cox proportional hazard models were used to determine the relative contributions of each stratum to cancer-specific survival. Predicted overall 10-year survival of Caucasian patients with testicular cancer increased slightly from 88% to 89% over the period studied, whereas predicted cancer-specific 10-year survival dropped slightly from 94% to 93%. In contrast, non-Caucasian men demonstrated larger changes in 10-year overall (84%-86%) and cancer-specific (88%-91%) survival. On univariate analysis, race was significantly associated with testicular cancer death, with non-Caucasian men being 1.69 times more likely to die of testicular cancer than Caucasians (hazard ratio, 1.33-2.16; 95% confidence interval, testicular cancer. These data show a convergence in cancer-specific survival between racial groups over time, suggesting that diagnostic and treatment discrepancies may be improving for non-Caucasians. Copyright © 2015 Elsevier Inc. All rights reserved.

Coyote removal, understory cover, and survival of white-tailed deer neonates: Coyote Control and Fawn Survival

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Kilgo, John C. [USDA Forest Service; Southern Research Station, New Ellenton, SC (United States); Vukovich, Mark [USDA Forest Service; Southern Research Station, New Ellenton, SC (United States); Ray, H. Scott [USDA Forest Service, Savannah River; New Ellenton, SC (United States); Shaw, Christopher E. [USDA Forest Service; Southern Research Station, New Ellenton, SC (United States); Ruth, Charles [South Carolina Dept. of Natural Resources, Columbia, SC (United States)

2014-09-01

Predation by coyotes (Canis latrans) on white-tailed deer (Odocoileus virginianus) neonates has led to reduced recruitment in many deer populations in southeastern North America. This low recruitment combined with liberal antlerless deer harvest has resulted in declines in some deer populations, and consequently, increased interest in coyote population control. We investigated whether neonate survival increased after coyote removal, whether coyote predation on neonates was additive to other mortality sources, and whether understory vegetation density affected neonate survival. We monitored neonate survival for 4 years prior to (2006–2009) and 3 years during (2010–2012) intensive coyote removal on 3 32-km² units on the United States Department of Energy’s Savannah River Site, South Carolina. We removed 474 coyotes (1.63 coyotes/km² per unit per year), reducing coyote abundance by 78% from pre-removal levels. The best model (w_i = 0.927) describing survival probability among 216 radio-collared neonates included a within-year quadratic time trend variable, date of birth, removal treatment, and a varying removal year effect. Under this model, survival differed between pre-treatment and removal periods and it differed among years during the removal period, being >100% greater than pre-treatment survival (0.228) during the first removal year (0.513), similar to pre-treatment survival during the second removal year (0.202), and intermediate during the third removal year (0.431). Despite an initial increase, the overall effect of coyote removal on neonate survival was modest. Mortality rate attributable to coyote predation was lowest during the first removal year (0.357) when survival was greatest, but the mortality rate from all other causes did not differ between the pretreatment period and any year during removals, indicating that coyote predation acted as an additive source of mortality. Survival probability was not related to

Swedish National Registry of Urinary Bladder Cancer: No difference in relative survival over time despite more aggressive treatment.

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Jahnson, Staffan; Hosseini Aliabad, Abolfazl; Holmäng, Sten; Jancke, Georg; Liedberg, Fredrik; Ljungberg, Börje; Malmström, Per-Uno; Rosell, Johan

2016-01-01

The aim of this study was to use the Swedish National Registry of Urinary Bladder Cancer (SNRUBC) to investigate changes in patient and tumour characteristics, management and survival in bladder cancer cases over a period of 15 years. All patients with newly detected bladder cancer reported to the SNRUBC during 1997-2011 were included in the study. The cohort was divided into three groups, each representing 5 years of the 15 year study period. The study included 31,266 patients (74% men, 26% women) with a mean age of 72 years. Mean age was 71.7 years in the first subperiod (1997-2001) and 72.5 years in the last subperiod (2007-2011). Clinical T categorization changed from the first to the last subperiod: Ta from 45% to 48%, T1 from 21.6% to 22.4%, and T2-T4 from 27% to 25%. Also from the first to the last subperiod, intravesical treatment after transurethral resection for T1G2 and T1G3 tumours increased from 15% to 40% and from 30% to 50%, respectively, and cystectomy for T2-T4 tumours increased from 30% to 40%. No differences between the analysed subperiods were found regarding relative survival in patients with T1 or T2-T4 tumours, or in the whole cohort. This investigation based on a national bladder cancer registry showed that the age of the patients at diagnosis increased, and the proportion of muscle-invasive tumours decreased. The treatment of all tumour stages became more aggressive but relative survival showed no statistically significant change over time.

The Philippine Parliamentarians Conference on Human Survival, Population and Development. Summary.

Science.gov (United States)

1988-12-01

Proceedings of the 1st Philippine Parliamentarians' Conference on Human Survival, Population and Development (PARLCON '88) are summarized in this report. Conference participants included the House and Senate, government officials, representatives of nongovernmental organizations, international organizations, the diplomatic corps and the media. A message from the President was read, referring the "silent emergency" of malnutrition and infant mortality of over 100,000 yearly. The events taking place were a statement of objectives, a Senate Resolution welcoming the convening of the conference, an opening ceremony, a posthumous award to R. M. Sales, executive director of the UNFPA, and a final a plan of action. Much of the content of the above events was duplicated in the final plan, which was formulated in 17 points. Some of these key points were: recognition of the need for quality of life, the detrimental effect of rapid population growth on development, the right of spouses to plan family size within their ethical beliefs, and the need for political will to address development concerns. The conference recommended that parliament and local governments strive for a consensus on national policy regarding population; ensure that economic gains are not decimated by population growth, protect the environment, develop social and industrial infrastructure in outlying areas, pursue national self-reliance, promote the human right of choosing desired family size, endorse the small family norm, empower women by educational and income generating opportunities, gather national data on population, strengthen the Population Commission, support nongovernmental agencies that provide family planning services, and promote education on family planning.

Tanacetum parthenium leaf extract mediated survival protection in lethally irradiated Swiss albino mice

International Nuclear Information System (INIS)

Shetty, Prashanth; Pooja, S.; Suchetha Kumari, N.; Shetty, Jayaram; Peter, Alex John; Jose, Jerish M.

2016-01-01

Search for less-toxic radioprotectors has spurred interest in the development of natural products. In Ayurveda, the traditional medicine, Tanacetum species have been used to treat ailments since ancient times throughout the world. Effects of the administration of different concentrations of Tanacetum parthenium leaf aqueous extract (TPLA), Tanacetum parthenium leaf ethanolic extract (TPLE) were investigated in Swiss albino mice. Mice (20-25 g) were randomly divided into 8 groups of ten animals each. The control group and the radiation group were treated daily with oral administration of saline for 15 days. Each subgroups of TPLA and TPLE were treated with doses of 50, 100 and 250 mg/kg daily for 15 days. On the 15th day, all were irradiated with 10 Gy whole body irradiation. Survival was observed daily up to 30th post-irradiation day. Data were analysed using the Kaplan-Meier survival curves. The significance difference in survival between control, radiation and treatment groups were observed (P < 0.001). Current studies revealed the protective effect of Tanacetum parthenium rendering high survivability in lethally irradiated mice. (author)

Cancer survival classification using integrated data sets and intermediate information.

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Kim, Shinuk; Park, Taesung; Kon, Mark

2014-09-01

Although numerous studies related to cancer survival have been published, increasing the prediction accuracy of survival classes still remains a challenge. Integration of different data sets, such as microRNA (miRNA) and mRNA, might increase the accuracy of survival class prediction. Therefore, we suggested a machine learning (ML) approach to integrate different data sets, and developed a novel method based on feature selection with Cox proportional hazard regression model (FSCOX) to improve the prediction of cancer survival time. FSCOX provides us with intermediate survival information, which is usually discarded when separating survival into 2 groups (short- and long-term), and allows us to perform survival analysis. We used an ML-based protocol for feature selection, integrating information from miRNA and mRNA expression profiles at the feature level. To predict survival phenotypes, we used the following classifiers, first, existing ML methods, support vector machine (SVM) and random forest (RF), second, a new median-based classifier using FSCOX (FSCOX_median), and third, an SVM classifier using FSCOX (FSCOX_SVM). We compared these methods using 3 types of cancer tissue data sets: (i) miRNA expression, (ii) mRNA expression, and (iii) combined miRNA and mRNA expression. The latter data set included features selected either from the combined miRNA/mRNA profile or independently from miRNAs and mRNAs profiles (IFS). In the ovarian data set, the accuracy of survival classification using the combined miRNA/mRNA profiles with IFS was 75% using RF, 86.36% using SVM, 84.09% using FSCOX_median, and 88.64% using FSCOX_SVM with a balanced 22 short-term and 22 long-term survivor data set. These accuracies are higher than those using miRNA alone (70.45%, RF; 75%, SVM; 75%, FSCOX_median; and 75%, FSCOX_SVM) or mRNA alone (65.91%, RF; 63.64%, SVM; 72.73%, FSCOX_median; and 70.45%, FSCOX_SVM). Similarly in the glioblastoma multiforme data, the accuracy of miRNA/mRNA using IFS

The frontotemporal syndrome of ALS is associated with poor survival.

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Govaarts, Rosanne; Beeldman, Emma; Kampelmacher, Mike J; van Tol, Marie-Jose; van den Berg, Leonard H; van der Kooi, Anneke J; Wijkstra, Peter J; Zijnen-Suyker, Marianne; Cobben, Nicolle A M; Schmand, Ben A; de Haan, Rob J; de Visser, Marianne; Raaphorst, Joost

2016-12-01

Thirty percent of ALS patients have a frontotemporal syndrome (FS), defined as behavioral changes or cognitive impairment. Despite previous studies, there are no firm conclusions on the effect of the FS on survival and the use of non-invasive ventilation (NIV) in ALS. We examined the effect of the FS on survival and the start and duration of NIV in ALS. Behavioral changes were defined as >22 points on the ALS-Frontotemporal-Dementia-Questionnaire or ≥3 points on ≥2 items of the Neuropsychiatric Inventory. Cognitive impairment was defined as below the fifth percentile on ≥2 tests of executive function, memory or language. Classic ALS was defined as ALS without the frontotemporal syndrome. We performed survival analyses from symptom onset and time from NIV initiation, respectively, to death. The impact of the explanatory variables on survival and NIV initiation were examined using Cox proportional hazards models. We included 110 ALS patients (76 men) with a mean age of 62 years. Median survival time was 4.3 years (95 % CI 3.53-5.13). Forty-seven patients (43 %) had an FS. Factors associated with shorter survival were FS, bulbar onset, older age at onset, short time to diagnosis and a C9orf72 repeat expansion. The adjusted hazard ratio (HR) for the FS was 2.29 (95 % CI 1.44-3.65, p NIV initiation (adjusted HR 2.70, 95 % CI 1.04-4.67, p = 0.04). In conclusion, there is an association between the frontotemporal syndrome and poor survival in ALS, which remains present after initiation of NIV.

The survival rate of self-immolators in Kermanshah Province 2010- 2011

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Farid Najafi

2013-12-01

Full Text Available Background: Self-immolation is one of the most violent methods of suicide, which is spreading in Iran. The highest rate of deaths due to committing suicide and self-immolation in Iran is observed in Kermanshah province. This research was conducted to study the survival rate and the factors that influence survival among the ones who commit self-immolation in Kermanshah province. Methods: In this study, all the cases who did not survive, as well as all the ones who were hospitalized due to self-immolation in Kermanshah province during 2010 and 2011 were examined. The Kaplan-Meier method was used to estimate the survival function, and in order to do the comparisons, Logrank test and Cox Regression were employed using Stata 12 software. Results: The results indicated that during 2010 and 2011, 343 individuals committed self-immolation in Kermanshah Province, while, 288 (84% were women. Also, it was found that 184 (53% did not survive, the mean and median of survival time in those who committed suicide deliberately, were 33±2.6 and 11±2 days respectively. Estimation of survival rate using Logrank test indicated that survival rate had a significant relationship with age, mental disorders, drug addiction, and TBSA (Total Body Surface Area, while it did not suggest a statistically significant relationship with gender, marital status and cause of injury. After multivariate analysis using Cox regression, only two variables of age and TBSA could remain in the model and the other variables were excluded from the model. Conclusion: The death toll due to self-immolation is very high and the mean and median of survival time among the people who committed self-immolation is very low. Therefore, it is recommended that remedial action be performed quickly without wasting time.

Camouflage predicts survival in ground-nesting birds.

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Troscianko, Jolyon; Wilson-Aggarwal, Jared; Stevens, Martin; Spottiswoode, Claire N

2016-01-29

Evading detection by predators is crucial for survival. Camouflage is therefore a widespread adaptation, but despite substantial research effort our understanding of different camouflage strategies has relied predominantly on artificial systems and on experiments disregarding how camouflage is perceived by predators. Here we show for the first time in a natural system, that survival probability of wild animals is directly related to their level of camouflage as perceived by the visual systems of their main predators. Ground-nesting plovers and coursers flee as threats approach, and their clutches were more likely to survive when their egg contrast matched their surrounds. In nightjars - which remain motionless as threats approach - clutch survival depended on plumage pattern matching between the incubating bird and its surrounds. Our findings highlight the importance of pattern and luminance based camouflage properties, and the effectiveness of modern techniques in capturing the adaptive properties of visual phenotypes.

Gastric Malignancy Survival in Zambia, Southern Africa: A Two Year ...

African Journals Online (AJOL)

Esem

numbers provided at time of enrollment. Corresponding author: ... duration of symptoms, treatment (surgery, chemotherapy, ... Zambia and no studies about management survival out comes. ... evaluated risk factors associated with gastric cancer survival in ... patients because patient financial limitations precluded testing for ...

Effects of young age at presentation on survival in breast cancer

International Nuclear Information System (INIS)

El Saghir, Nagi S; Seoud, Muhieddine; Khalil, Mazen K; Charafeddine, Maya; Salem, Ziad K; Geara, Fady B; Shamseddine, Ali I

2006-01-01

Young age remains a controversial issue as a prognostic factor in breast cancer. Debate includes patients from different parts of the world. Almost 50% of patients with breast cancer seen at the American University of Beirut Medical Center (AUBMC) are below age 50. We reviewed 1320 patients seen at AUBMC between 1990 and 2001. We divided them in three age groups: Below 35, 35–50, and above 50. Data and survival were analyzed using Chi-square, Cox regression analysis, and Kaplan Meier. Mean age at presentation was 50.8 years. 107 patients were below age 35, 526 between 35–50 and 687 patients above age 50. Disease stages were as follows: stage I: 14.4%, stage II: 59.9%, stage III: 20% and stage IV: 5.7%. Hormone receptors were positive in 71.8% of patients below 35, in 67.6% of patients 35–50 and in 78.3% of patients above 50. Grade of tumor was higher as age at presentation was lower. More young patients received anthracycline-based adjuvant chemotherapy. Of hormone receptor-positive patients, 83.8% of those below age 35 years, 87.76% of those aged 35–50 years, and 91.2% of those aged above 50 years received adjuvant tamoxifen. The mean follow up time was 3.7 +/- 2.9 years. Time to death was the only variable analyzed for survival analysis. Excluding stage IV patients, tumor size, lymph node, tumor grade and negative hormone receptors were inversely proportional to survival. Higher percentage of young patients at presentation developed metastasis (32.4% of patients below 35, as compared to 22.9% of patients 35–50 and 22.8% of patients above 50) and had a worse survival. Young age had a negative impact on survival of patients with positive axillary lymph nodes, and survival of patients with positive hormonal receptors, but not on survival of patients with negative lymph nodes, or patients with negative hormonal receptors. Young age at presentation conferred a worse prognosis in spite of a higher than expected positive hormone receptor status, more

Breeding Young as a Survival Strategy during Earth’s Greatest Mass Extinction

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Botha-Brink, Jennifer; Codron, Daryl; Huttenlocker, Adam K.; Angielczyk, Kenneth D.; Ruta, Marcello

2016-04-01

Studies of the effects of mass extinctions on ancient ecosystems have focused on changes in taxic diversity, morphological disparity, abundance, behaviour and resource availability as key determinants of group survival. Crucially, the contribution of life history traits to survival during terrestrial mass extinctions has not been investigated, despite the critical role of such traits for population viability. We use bone microstructure and body size data to investigate the palaeoecological implications of changes in life history strategies in the therapsid forerunners of mammals before and after the Permo-Triassic Mass Extinction (PTME), the most catastrophic crisis in Phanerozoic history. Our results are consistent with truncated development, shortened life expectancies, elevated mortality rates and higher extinction risks amongst post-extinction species. Various simulations of ecological dynamics indicate that an earlier onset of reproduction leading to shortened generation times could explain the persistence of therapsids in the unpredictable, resource-limited Early Triassic environments, and help explain observed body size distributions of some disaster taxa (e.g., Lystrosaurus). Our study accounts for differential survival in mammal ancestors after the PTME and provides a methodological framework for quantifying survival strategies in other vertebrates during major biotic crises.

Multiple neoplasms, single primaries, and patient survival

International Nuclear Information System (INIS)

Amer, Magid H

2014-01-01

Multiple primary neoplasms in surviving cancer patients are relatively common, with an increasing incidence. Their impact on survival has not been clearly defined. This was a retrospective review of clinical data for all consecutive patients with histologically confirmed cancer, with emphasis on single versus multiple primary neoplasms. Second primaries discovered at the workup of the index (first) primary were termed simultaneous, if discovered within 6 months of the index primary were called synchronous, and if discovered after 6 months were termed metachronous. Between 2005 and 2012, of 1,873 cancer patients, 322 developed second malignancies; these included two primaries (n=284), and three or more primaries (n=38). Forty-seven patients had synchronous primaries and 275 had metachronous primaries. Patients with multiple primaries were predominantly of Caucasian ancestry (91.0%), with a tendency to develop thrombosis (20.2%), had a strong family history of similar cancer (22.3%), and usually presented with earlier stage 0 through stage II disease (78.9%). When compared with 1,551 patients with a single primary, these figures were 8.9%, 15.6%, 18.3%, and 50.9%, respectively (P≤0.001). Five-year survival rates were higher for metachronous cancers (95%) than for synchronous primaries (59%) and single primaries (59%). The worst survival rate was for simultaneous concomitant multiple primaries, being a median of 1.9 years. The best survival was for patients with three or more primaries (median 10.9 years) and was similar to the expected survival for the age-matched and sex-matched general population (P=0.06991). Patients with multiple primaries are usually of Caucasian ancestry, have less aggressive malignancies, present at earlier stages, frequently have a strong family history of similar cancer, and their cancers tend to have indolent clinical behavior with longer survival rates, possibly related to genetic predisposition

Development of a Summarized Health Index (SHI) for Use in Predicting Survival in Sea Turtles

Science.gov (United States)

Li, Tsung-Hsien; Chang, Chao-Chin; Cheng, I-Jiunn; Lin, Suen-Chuain

2015-01-01

Veterinary care plays an influential role in sea turtle rehabilitation, especially in endangered species. Physiological characteristics, hematological and plasma biochemistry profiles, are useful references for clinical management in animals, especially when animals are during the convalescence period. In this study, these factors associated with sea turtle surviving were analyzed. The blood samples were collected when sea turtles remained alive, and then animals were followed up for surviving status. The results indicated that significantly negative correlation was found between buoyancy disorders (BD) and sea turtle surviving (p turtles had significantly higher levels of aspartate aminotranspherase (AST), creatinine kinase (CK), creatinine and uric acid (UA) than surviving sea turtles (all p turtles and to improve veterinary care at rehabilitation facilities. PMID:25803431

Survival analysis of a treatment data for cancer of the larynx

International Nuclear Information System (INIS)

Khan, K.

2002-01-01

In this paper a survival analysis of the survival time is done. The Cox regression model is fitted to the survival time with the assumption of proportional hazard. A model is selected after inclusion and exclusion of factors and variables as explanatory variables. The assumption of proportional hazards is tested in the manner suggested by Harrell (1986). The assumption of proportional hazards is supported by these tests. However the plot of Schoenfeld residuals against dose gave a little evidence of non validity of the proportional hazard assumption. The assumption seems to be satisfied for variable time. The martingale residuals suggest no pattern for variable age. The functional form of dose is not linear. Hence the quadratic dose is used as an explanatory variable. A comparison of logistic regression analysis and survival analysis is also made in this paper. It can be concluded that Cox proportional hazards model is a better model than the logistic model as it is more parsimonious and utilizes more information. (author)

Fifteen-Year Biochemical Relapse-Free Survival, Cause-Specific Survival, and Overall Survival Following I125 Prostate Brachytherapy in Clinically Localized Prostate Cancer: Seattle Experience

International Nuclear Information System (INIS)

Sylvester, John E.; Grimm, Peter D.; Wong, Jason; Galbreath, Robert W.; Merrick, Gregory; Blasko, John C.

2011-01-01

Purpose: To report 15-year biochemical relapse-free survival (BRFS), cause-specific survival (CSS), and overall survival (OS) outcomes of patients treated with I 125 brachytherapy monotherapy for clinically localized prostate cancer early in the Seattle experience. Methods and Materials: Two hundred fifteen patients with clinically localized prostate cancer were consecutively treated from 1988 to 1992 with I 125 monotherapy. They were prospectively followed as a tight cohort. They were evaluated for BRFS, CSS, and OS. Multivariate analysis was used to evaluate outcomes by pretreatment clinical prognostic factors. BRFS was analyzed by the Phoenix (nadir + 2 ng/mL) definition. CSS and OS were evaluated by chart review, death certificates, and referring physician follow-up notes. Gleason scoring was performed by general pathologists at a community hospital in Seattle. Time to biochemical failure (BF) was calculated and compared by Kaplan-Meier plots. Results: Fifteen-year BRFS for the entire cohort was 80.4%. BRFS by D'Amico risk group classification cohort analysis was 85.9%, 79.9%, and 62.2% for low, intermediate, and high-risk patients, respectively. Follow-up ranged from 3.6 to 18.4 years; median follow-up was 15.4 years for biochemically free of disease patients. Overall median follow-up was 11.7 years. The median time to BF in those who failed was 5.1 years. CSS was 84%. OS was 37.1%. Average age at time of treatment was 70 years. There was no significant difference in BRFS between low and intermediate risk groups. Conclusion: I 125 monotherapy results in excellent 15-year BRFS and CSS, especially when taking into account the era of treatment effect.

Survival and clinical outcome of dogs with ischaemic stroke.

Science.gov (United States)

Gredal, H; Toft, N; Westrup, U; Motta, L; Gideon, P; Arlien-Søborg, P; Skerritt, G C; Berendt, M

2013-06-01

The objectives of the present study were to investigate survival time, possible predictors of survival and clinical outcome in dogs with ischaemic stroke. A retrospective study of dogs with a previous diagnosis of ischaemic stroke diagnosed by magnetic resonance imaging (MRI) was performed. The association between survival and the hypothesised risk factors was examined using univariable exact logistic regression. Survival was examined using Kaplan-Meier and Cox regression. Twenty-two dogs were identified. Five dogs (23%) died within the first 30days of the stroke event. Median survival in 30-day survivors was 505days. Four dogs (18%) were still alive by the end of the study. Right-sided lesions posed a significantly increased risk of mortality with a median survival time in dogs with right-sided lesions of 24days vs. 602days in dogs with left sided lesions (P=0.006). Clinical outcome was considered excellent in seven of 17 (41%) 30-day survivors. Another seven 30-day survivors experienced new acute neurological signs within 6-17months of the initial stroke event; in two of those cases a new ischaemic stroke was confirmed by MRI. In conclusion, dogs with ischaemic stroke have a fair to good prognosis in terms of survival and clinical outcome. However, owners should be informed of the risk of acute death within 30days and of the possibility of new neurological events in survivors. Mortality was increased in dogs with right-sided lesions in this study. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hepatocyte transplantation improves early survival after partial hepatic resection and irradiation

International Nuclear Information System (INIS)

Guha, C.; Sharma, A.; Alfieri, A.; Guha, U.; Sokhi, R.; Gagandeep, S.; Gupta, S.; Vikram, B.; RoyChowdhury, J.

1997-01-01

Purpose: Radiation therapy (RT) is limited in its role as an adjuvant therapy of intrahepatic malignancies because of lower tolerance of human liver to irradiation (TD (5(5)) -TD (50(5)) ∼ 30-40 Gy). Although, surgical resection of primary or metastatic hepatic tumors has been shown to prolong survival, it is often limited by the presence of residual disease. RT could potentially improve survival of patients with positive surgical margins. However, radiation damage to the liver may be enhanced by hepatocellular proliferation induced by partial hepatic (PH) resection. We hypothesize that hepatocyte transplantation would be able to provide metabolic support and modulate the development of radiation-induced liver disease post-resection. The present study was designed to test the potential of hepatocyte transplantation in modifying the outcome of hepatocellular damage induced by PH and RT. Methods: Adult male Fischer 344 rats (Charles River) received hepatic irradiation of 50 Gy in a single fraction, after surgical exposure and shielding of the stomach and intestine, using a 320 MGC Philips orthovoltage unit. Immediately following irradiation, a two-third partial hepatectomy was performed. Four days post-radiation, the treatment group was injected with 5 x 10 6 syngeneic hepatocytes into the splenic pulp after a left subcostal incision, which allows homogeneous liver engraftment of the transplanted hepatocytes. Hematoxylin and eosin stains of liver biopsies, performed at various time points (3 days, 1, 2, 3 weeks or, anytime when animals died) were used for histologic evaluation. Time-adjusted survival was calculated from the date of irradiation by the product-limit Kaplan-Meier method, adjusting the denominator at every time point for the number of rats at risk. Results: Eight weeks after RT, 30% (n = 11) of the control animals (PH + 50 Gy) were alive compared to 100% (n = 9) of the transplant recipients (p <0.05). The median survival of the control group was 15