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

The survival time of chocolates on hospital wards: covert observational study.

Science.gov (United States)

Gajendragadkar, Parag R; Moualed, Daniel J; Nicolson, Phillip L R; Adjei, Felicia D; Cakebread, Holly E; Duehmke, Rudolf M; Martin, Claire A

2013-12-14

To quantify the consumption of chocolates in a hospital ward environment. Multicentre, prospective, covert observational study. Four wards at three hospitals (where the authors worked) within the United Kingdom. Boxes of Quality Street (Nestlé) and Roses (Cadbury) on the ward and anyone eating these chocolates. Observers covertly placed two 350 g boxes of Quality Street and Roses chocolates on each ward (eight boxes were used in the study containing a total of 258 individual chocolates). These boxes were kept under continuous covert surveillance, with the time recorded when each chocolate was eaten. Median survival time of a chocolate. 191 out of 258 (74%) chocolates were observed being eaten. The mean total observation period was 254 minutes (95% confidence interval 179 to 329). The median survival time of a chocolate was 51 minutes (39 to 63). The model of chocolate consumption was non-linear, with an initial rapid rate of consumption that slowed with time. An exponential decay model best fitted these findings (model R(2)=0.844, P<0.001), with a survival half life (time taken for 50% of the chocolates to be eaten) of 99 minutes. The mean time taken to open a box of chocolates from first appearance on the ward was 12 minutes (95% confidence interval 0 to 24). Quality Street chocolates survived longer than Roses chocolates (hazard ratio for survival of Roses v Quality Street 0.70, 95% confidence interval 0.53 to 0.93, P=0.014). The highest percentages of chocolates were consumed by healthcare assistants (28%) and nurses (28%), followed by doctors (15%). From our observational study, chocolate survival in a hospital ward was relatively short, and was modelled well by an exponential decay model. Roses chocolates were preferentially consumed to Quality Street chocolates in a ward setting. Chocolates were consumed primarily by healthcare assistants and nurses, followed by doctors. Further practical studies are needed.

Association between time to disease progression end points and overall survival in patients with neuroendocrine tumors

Directory of Open Access Journals (Sweden)

Singh S

2014-08-01

Full Text Available Simron Singh,1 Xufang Wang,2 Calvin HL Law1 1Sunnybrook Odette Cancer Center, University of Toronto, Toronto, ON, Canada; 2Novartis Oncology, Florham Park, NJ, USA Abstract: Overall survival can be difficult to determine for slowly progressing malignancies, such as neuroendocrine tumors. We investigated whether time to disease progression is positively associated with overall survival in patients with such tumors. A literature review identified 22 clinical trials in patients with neuroendocrine tumors that reported survival probabilities for both time to disease progression (progression-free survival and time to progression and overall survival. Associations between median time to disease progression and median overall survival and between treatment effects on time to disease progression and treatment effects on overall survival were analyzed using weighted least-squares regression. Median time to disease progression was significantly associated with median overall survival (coefficient 0.595; P=0.022. In the seven randomized studies identified, the risk reduction for time to disease progression was positively associated with the risk reduction for overall survival (coefficient on −ln[HR] 0.151; 95% confidence interval −0.843, 1.145; P=0.713. The significant association between median time to disease progression and median overall survival supports the assertion that time to disease progression is an alternative end point to overall survival in patients with neuroendocrine tumors. An apparent albeit not significant trend correlates treatment effects on time to disease progression and treatment effects on overall survival. Informal surveys of physicians’ perceptions are consistent with these concepts, although additional randomized trials are needed. Keywords: neuroendocrine tumors, progression-free survival, disease progression, mortality

Integral Time and the Varieties of Post-Mortem Survival

Directory of Open Access Journals (Sweden)

Sean M. Kelly

2008-06-01

Full Text Available While the question of survival of bodily death is usually approached byfocusing on the mind/body relation (and often with the idea of the soul as a special kindof substance, this paper explores the issue in the context of our understanding of time.The argument of the paper is woven around the central intuition of time as an “everlivingpresent.” The development of this intuition allows for a more integral or “complexholistic”theory of time, the soul, and the question of survival. Following the introductorymatter, the first section proposes a re-interpretation of Nietzsche’s doctrine of eternalrecurrence in terms of moments and lives as “eternally occurring.” The next section is atreatment of Julian Barbour’s neo-Machian model of instants of time as configurations inthe n-dimensional phase-space he calls “Platonia.” While rejecting his claim to have doneaway with time, I do find his model suggestive of the idea of moments and lives aseternally occurring. The following section begins with Fechner’s visionary ideas of thenature of the soul and its survival of bodily death, with particular attention to the notionof holonic inclusion and the central analogy of the transition from perception to memory.I turn next to Whitehead’s equally holonic notions of prehension and the concrescence ofactual occasions. From his epochal theory of time and certain ambiguities in hisreflections on the “divine antinomies,” we are brought to the threshold of a potentiallymore integral or “complex-holistic” theory of time and survival, which is treated in thelast section. This section draws from my earlier work on Hegel, Jung, and Edgar Morin,as well as from key insights of Jean Gebser, for an interpretation of Sri Aurobindo’sinspired but cryptic description of the “Supramental Time Vision.” This interpretationleads to an alternative understanding of reincarnation—and to the possibility of itsreconciliation with the once-only view

Helicopter crashes into water: warning time, final position, and other factors affecting survival.

Science.gov (United States)

Brooks, Christopher J; MacDonald, Conor V; Baker, Susan P; Shanahan, Dennis F; Haaland, Wren L

2014-04-01

According to 40 yr of data, the fatality rate for a helicopter crash into water is approximately 25%. Does warning time and the final position of the helicopter in the water influence the survival rate? The National Transportation Safety Board (NTSB) database was queried to identify helicopter crashes into water between 1981 and 2011 in the Gulf of Mexico and Hawaii. Fatality rate, amount of warning time prior to the crash, and final position of the helicopter were identified. There were 133 helicopters that crashed into water with 456 crew and passengers. Of these, 119 occupants (26%) did not survive; of those who did survive, 38% were injured. Twelve died after making a successful escape from the helicopter. Crashes with 1 min. However, more than half of fatalities (57%) came from crashes for which the warning time could not be determined. Lack of warning time and how to survive in the water after the crash should be a topic for study in all marine survival/aircraft ditching courses. Investigators should be trained to provide estimates of warning time when investigating helicopter crashes into water.

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

Directory of Open Access Journals (Sweden)

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%.

Clever mothers balance time and effort in parental care: a study on free-ranging dogs

OpenAIRE

Paul, Manabi; Sau, Shubhra; Nandi, Anjan K.; Bhadra, Anindita

2016-01-01

Mammalian offspring require parental care, at least in the form of suckling during their early development. While mothers need to invest considerable time and energy in ensuring the survival of their current offspring, they also need to optimize their investment in one batch of offspring in order to ensure future reproduction and hence lifetime reproductive success. Free-ranging dogs live in small social groups, mate promiscuously, and lack the cooperative breeding biology of other group livi...

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

Science.gov (United States)

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.

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...

Integral Time and the Varieties of Post-Mortem Survival

Directory of Open Access Journals (Sweden)

Sean M. Kelly

2008-06-01

Full Text Available While the question of survival of bodily death is usually approached by focusing on the mind/body relation (and often with the idea of the soul as a special kind of substance, this paper explores the issue in the context of our understanding of time. The argument of the paper is woven around the central intuition of time as an “ever-living present.” The development of this intuition allows for a more integral or “complex-holistic” theory of time, the soul, and the question of survival. Following the introductory matter, the first section proposes a re-interpretation of Nietzsche’s doctrine of eternal recurrence in terms of moments and lives as “eternally occurring.” The next section is a treatment of Julian Barbour’s neo-Machian model of instants of time as configurations in the n-dimensional phase-space he calls “Platonia.” While rejecting his claim to have done away with time, I do find his model suggestive of the idea of moments and lives as eternally occurring. The following section begins with Fechner’s visionary ideas of the nature of the soul and its survival of bodily death, with particular attention to the notion of holonic inclusion and the central analogy of the transition from perception to memory. I turn next to Whitehead’s equally holonic notions of prehension and the concrescence of actual occasions. From his epochal theory of time and certain ambiguities in his reflections on the “divine antinomies,” we are brought to the threshold of a potentially more integral or “complex-holistic” theory of time and survival, which is treated in the last section. This section draws from my earlier work on Hegel, Jung, and Edgar Morin, as well as from key insights of Jean Gebser, for an interpretation of Sri Aurobindo’s inspired but cryptic description of the “Supramental Time Vision.” This interpretation leads to an alternative understanding of reincarnation—and to the possibility of its reconciliation

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

Science.gov (United States)

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.

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

Science.gov (United States)

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

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

Directory of Open Access Journals (Sweden)

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.

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

OpenAIRE

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.

Science.gov (United States)

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.

Science.gov (United States)

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.

What affects local community hospitals' survival in turbulent times?

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

OpenAIRE

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...

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.

Science.gov (United States)

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

Science.gov (United States)

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...

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...

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.

Science.gov (United States)

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.

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

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.

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 ...

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.

Clever mothers balance time and effort in parental care: a study on free-ranging dogs.

Science.gov (United States)

Paul, Manabi; Sau, Shubhra; Nandi, Anjan K; Bhadra, Anindita

2017-01-01

Mammalian offspring require parental care, at least in the form of nursing during their early development. While mothers need to invest considerable time and energy in ensuring the survival of their current offspring, they also need to optimize their investment in one batch of offspring in order to ensure future reproduction and hence lifetime reproductive success. Free-ranging dogs live in small social groups, mate promiscuously and lack the cooperative breeding biology of other group-living canids. They face high early-life mortality, which in turn reduces fitness benefits of the mother from a batch of pups. We carried out a field-based study on free-ranging dogs in India to understand the nature of maternal care. Our analysis reveals that mothers reduce investment in energy-intensive active care and increase passive care as the pups grow older, thereby keeping overall levels of care more or less constant over pup age. Using the patterns of mother-pup interactions, we define the different phases of maternal care behaviour.

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.

Science.gov (United States)

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.

Survivable architectures for time and wavelength division multiplexed passive optical networks

Science.gov (United States)

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.

Effects of mercury on health and first-year survival of free-ranging great egrets (Ardea albus) from southern Florida.

Science.gov (United States)

Sepúlveda, M S; Williams, G E; Frederick, P C; Spalding, M G

1999-10-01

The objectives of this study were to determine whether elevated mercury (Hg) concentrations have a negative impact on the health and survival of nestling and juvenile free-ranging great egrets (Ardea albus) from southern Florida. During 1994, when health and survival was monitored in a cohort of young birds with naturally variable concentrations of Hg, packed cell volume was positively correlated with blood Hg concentrations, and high Hg concentration in blood was not related to the probability of surviving during the first 10.5 months of life. During 1995, 70 first-hatched great egret chicks were included in a Hg field-dosing experiment to compare the effects of elevated Hg on health and survival. Birds were dosed while in the nest orally every 2.5 days for 15 days with 0.5 mg of methyl mercury chloride (MeHgCl) for an estimated intake of 1.54 mg MeHgCl/kg food intake. These birds were compared with controls, which received an estimated 0.41 mg MeHgCl/kg food. No differences were observed in health parameters or in the probability of surviving during the first 8 months of age between egrets that were dosed with Hg and those that were not. A likely explanation for the lack of any effects on health and survival between both groups could be that chicks at this age were eliminating most of the dietary Hg through the production of new feathers.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

KMWin--a convenient tool for graphical presentation of results from Kaplan-Meier survival time analysis.

Science.gov (United States)

Gross, Arnd; Ziepert, Marita; Scholz, Markus

2012-01-01

Analysis of clinical studies often necessitates multiple graphical representations of the results. Many professional software packages are available for this purpose. Most packages are either only commercially available or hard to use especially if one aims to generate or customize a huge number of similar graphical outputs. We developed a new, freely available software tool called KMWin (Kaplan-Meier for Windows) facilitating Kaplan-Meier survival time analysis. KMWin is based on the statistical software environment R and provides an easy to use graphical interface. Survival time data can be supplied as SPSS (sav), SAS export (xpt) or text file (dat), which is also a common export format of other applications such as Excel. Figures can directly be exported in any graphical file format supported by R. On the basis of a working example, we demonstrate how to use KMWin and present its main functions. We show how to control the interface, customize the graphical output, and analyse survival time data. A number of comparisons are performed between KMWin and SPSS regarding graphical output, statistical output, data management and development. Although the general functionality of SPSS is larger, KMWin comprises a number of features useful for survival time analysis in clinical trials and other applications. These are for example number of cases and number of cases under risk within the figure or provision of a queue system for repetitive analyses of updated data sets. Moreover, major adjustments of graphical settings can be performed easily on a single window. We conclude that our tool is well suited and convenient for repetitive analyses of survival time data. It can be used by non-statisticians and provides often used functions as well as functions which are not supplied by standard software packages. The software is routinely applied in several clinical study groups.

KMWin--a convenient tool for graphical presentation of results from Kaplan-Meier survival time analysis.

Directory of Open Access Journals (Sweden)

Arnd Gross

Full Text Available BACKGROUND: Analysis of clinical studies often necessitates multiple graphical representations of the results. Many professional software packages are available for this purpose. Most packages are either only commercially available or hard to use especially if one aims to generate or customize a huge number of similar graphical outputs. We developed a new, freely available software tool called KMWin (Kaplan-Meier for Windows facilitating Kaplan-Meier survival time analysis. KMWin is based on the statistical software environment R and provides an easy to use graphical interface. Survival time data can be supplied as SPSS (sav, SAS export (xpt or text file (dat, which is also a common export format of other applications such as Excel. Figures can directly be exported in any graphical file format supported by R. RESULTS: On the basis of a working example, we demonstrate how to use KMWin and present its main functions. We show how to control the interface, customize the graphical output, and analyse survival time data. A number of comparisons are performed between KMWin and SPSS regarding graphical output, statistical output, data management and development. Although the general functionality of SPSS is larger, KMWin comprises a number of features useful for survival time analysis in clinical trials and other applications. These are for example number of cases and number of cases under risk within the figure or provision of a queue system for repetitive analyses of updated data sets. Moreover, major adjustments of graphical settings can be performed easily on a single window. CONCLUSIONS: We conclude that our tool is well suited and convenient for repetitive analyses of survival time data. It can be used by non-statisticians and provides often used functions as well as functions which are not supplied by standard software packages. The software is routinely applied in several clinical study groups.

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.

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.

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.

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.

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…

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

Real-time high dynamic range laser scanning microscopy

Science.gov (United States)

Vinegoni, C.; Leon Swisher, C.; Fumene Feruglio, P.; Giedt, R. J.; Rousso, D. L.; Stapleton, S.; Weissleder, R.

2016-04-01

In conventional confocal/multiphoton fluorescence microscopy, images are typically acquired under ideal settings and after extensive optimization of parameters for a given structure or feature, often resulting in information loss from other image attributes. To overcome the problem of selective data display, we developed a new method that extends the imaging dynamic range in optical microscopy and improves the signal-to-noise ratio. Here we demonstrate how real-time and sequential high dynamic range microscopy facilitates automated three-dimensional neural segmentation. We address reconstruction and segmentation performance on samples with different size, anatomy and complexity. Finally, in vivo real-time high dynamic range imaging is also demonstrated, making the technique particularly relevant for longitudinal imaging in the presence of physiological motion and/or for quantification of in vivo fast tracer kinetics during functional imaging.

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.

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

Time-related survival effects of two gluconasturtiin hydrolysis products on the terrestrial isopod Porcellio scaber

DEFF Research Database (Denmark)

van Ommen Kloeke, A E Elaine; Jager, Tjalling; van Gestel, Cornelis A. M.

2012-01-01

Glucosinolates are compounds produced by commercial crops which can hydrolyse in a range of natural toxins that may exert detrimental effects on beneficial soil organisms. This study examined the effects of 2-phenylethyl isothiocyanate and 3-phenylpropionitrile on the survival and growth of the w...

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 ...

Pulse Based Time-of-Flight Range Sensing.

Science.gov (United States)

Sarbolandi, Hamed; Plack, Markus; Kolb, Andreas

2018-05-23

Pulse-based Time-of-Flight (PB-ToF) cameras are an attractive alternative range imaging approach, compared to the widely commercialized Amplitude Modulated Continuous-Wave Time-of-Flight (AMCW-ToF) approach. This paper presents an in-depth evaluation of a PB-ToF camera prototype based on the Hamamatsu area sensor S11963-01CR. We evaluate different ToF-related effects, i.e., temperature drift, systematic error, depth inhomogeneity, multi-path effects, and motion artefacts. Furthermore, we evaluate the systematic error of the system in more detail, and introduce novel concepts to improve the quality of range measurements by modifying the mode of operation of the PB-ToF camera. Finally, we describe the means of measuring the gate response of the PB-ToF sensor and using this information for PB-ToF sensor simulation.

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

KMWin – A Convenient Tool for Graphical Presentation of Results from Kaplan-Meier Survival Time Analysis

Science.gov (United States)

Gross, Arnd; Ziepert, Marita; Scholz, Markus

2012-01-01

Background Analysis of clinical studies often necessitates multiple graphical representations of the results. Many professional software packages are available for this purpose. Most packages are either only commercially available or hard to use especially if one aims to generate or customize a huge number of similar graphical outputs. We developed a new, freely available software tool called KMWin (Kaplan-Meier for Windows) facilitating Kaplan-Meier survival time analysis. KMWin is based on the statistical software environment R and provides an easy to use graphical interface. Survival time data can be supplied as SPSS (sav), SAS export (xpt) or text file (dat), which is also a common export format of other applications such as Excel. Figures can directly be exported in any graphical file format supported by R. Results On the basis of a working example, we demonstrate how to use KMWin and present its main functions. We show how to control the interface, customize the graphical output, and analyse survival time data. A number of comparisons are performed between KMWin and SPSS regarding graphical output, statistical output, data management and development. Although the general functionality of SPSS is larger, KMWin comprises a number of features useful for survival time analysis in clinical trials and other applications. These are for example number of cases and number of cases under risk within the figure or provision of a queue system for repetitive analyses of updated data sets. Moreover, major adjustments of graphical settings can be performed easily on a single window. Conclusions We conclude that our tool is well suited and convenient for repetitive analyses of survival time data. It can be used by non-statisticians and provides often used functions as well as functions which are not supplied by standard software packages. The software is routinely applied in several clinical study groups. PMID:22723912

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)

Bacterial intelligence: imitation games, time-sharing, and long-range quantum coherence.

Science.gov (United States)

Majumdar, Sarangam; Pal, Sukla

2017-09-01

Bacteria are far more intelligent than we can think of. They adopt different survival strategies to make their life comfortable. Researches on bacterial communication to date suggest that bacteria can communicate with each other using chemical signaling molecules as well as using ion channel mediated electrical signaling. Though in past few decades the scopes of chemical signaling have been investigated extensively, those of electrical signaling have received less attention. In this article, we present a novel perspective on time-sharing behavior, which maintains the biofilm growth under reduced nutrient supply between two distant biofilms through electrical signaling based on the experimental evidence reported by Liu et al., in 2017. In addition, following the recent work by Humphries et al. Cell 168(1):200-209, in 2017, we highlight the consequences of long range electrical signaling within biofilm communities through spatially propagating waves of potassium. Furthermore, we address the possibility of two-way cellular communication between artificial and natural cells through chemical signaling being inspired by recent experimental observation (Lentini et al. 2017) where the efficiency of artificial cells in imitating the natural cells is estimated through cellular Turing test. These three spectacular observations lead us to envisage and devise new classical and quantum views of these complex biochemical networks that have never been realized previously.

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

Science.gov (United States)

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

Low larval densities in northern populations reinforce range expansion by a Mediterranean damselfly

DEFF Research Database (Denmark)

Therry, Lieven; Swaegers, Janne; Dinh, Khuong Van

2016-01-01

indicated higher food availability at low conspecific densities. Interestingly, the initial density treatment had stronger effect than densities experienced at the time of quantification on survival during the pre-freezing winter period and body condition estimates at the end of the experiment, indicating...... also delayed effects of the initial density treatment. Survival throughout a freezing period indicated extreme winter conditions are not likely a limiting factor in the range expansion of this Mediterranean species. 4. The increased survival and individual growth rates (through causing shifts......1. Contemporary climate change triggers a poleward range shift in many species. A growing number of studies document evolutionary changes in traits accelerating range expansion (such as growth rate and dispersal-related traits). In contrast, the direct impact of decreasing conspecific densities...

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

Directory of Open Access Journals (Sweden)

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.

Science.gov (United States)

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

Directory of Open Access Journals (Sweden)

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

Directory of Open Access Journals (Sweden)

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.

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

Hydronephrosis in patients with cervical cancer: an assessment of morbidity and survival.

Science.gov (United States)

Patel, Krishna; Foster, Nathan R; Kumar, Amanika; Grudem, Megan; Longenbach, Sherri; Bakkum-Gamez, Jamie; Haddock, Michael; Dowdy, Sean; Jatoi, Aminah

2015-05-01

Hydronephrosis is a frequently observed but understudied complication in patients with cervical cancer. To better characterize hydronephrosis in cervical cancer patients, the current study sought (1) to describe hydronephrosis-associated morbidity and (2) to analyze the prognostic effect of hydronephrosis in patients with a broad range of cancer stages over time. The Mayo Clinic Tumor Registry was interrogated for all invasive cervical cancer patients seen at the Mayo Clinic from 2008 through 2013 in Rochester, Minnesota; these patients' medical records were then reviewed in detail. Two hundred seventy-nine cervical cancer patients with a median age of 49 years and a range of cancer stages were included. Sixty-five patients (23 %) were diagnosed with hydronephrosis at some point during their disease course. In univariate analyses, hydronephrosis was associated with advanced cancer stage (p hydronephrosis. All but one patient underwent stent placement or urinary diversion; hydronephrosis-related morbidity included pain, urinary tract infections, nausea and vomiting, renal failure, and urinary tract bleeding. In landmark univariate survival analyses, hydronephrosis was associated with worse survival at all time points. In landmark multivariate analyses (adjusted for patient age, stage, cancer treatment, and tumor histology), hydronephrosis was associated with a trend toward worse survival over time (hazard ratios ranged from 1.47 to 4.69). Hydronephrosis in cervical cancer patients is associated with notable morbidity. It is also associated with trends toward worse survival-even if it occurs after the original cancer diagnosis.

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

Directory of Open Access Journals (Sweden)

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.

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

International Nuclear Information System (INIS)

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.)

Extreme climatic events constrain space use and survival of a ground-nesting bird.

Science.gov (United States)

Tanner, Evan P; Elmore, R Dwayne; Fuhlendorf, Samuel D; Davis, Craig A; Dahlgren, David K; Orange, Jeremy P

2017-05-01

Two fundamental issues in ecology are understanding what influences the distribution and abundance of organisms through space and time. While it is well established that broad-scale patterns of abiotic and biotic conditions affect organisms' distributions and population fluctuations, discrete events may be important drivers of space use, survival, and persistence. These discrete extreme climatic events can constrain populations and space use at fine scales beyond that which is typically measured in ecological studies. Recently, a growing body of literature has identified thermal stress as a potential mechanism in determining space use and survival. We sought to determine how ambient temperature at fine temporal scales affected survival and space use for a ground-nesting quail species (Colinus virginianus; northern bobwhite). We modeled space use across an ambient temperature gradient (ranging from -20 to 38 °C) through a maxent algorithm. We also used Andersen-Gill proportional hazard models to assess the influence of ambient temperature-related variables on survival through time. Estimated available useable space ranged from 18.6% to 57.1% of the landscape depending on ambient temperature. The lowest and highest ambient temperature categories (35 °C, respectively) were associated with the least amount of estimated useable space (18.6% and 24.6%, respectively). Range overlap analysis indicated dissimilarity in areas where Colinus virginianus were restricted during times of thermal extremes (range overlap = 0.38). This suggests that habitat under a given condition is not necessarily a habitat under alternative conditions. Further, we found survival was most influenced by weekly minimum ambient temperatures. Our results demonstrate that ecological constraints can occur along a thermal gradient and that understanding the effects of these discrete events and how they change over time may be more important to conservation of organisms than are average and broad

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

Energy Technology Data Exchange (ETDEWEB)

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.

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.

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...

Time-delay interferometric ranging for space-borne gravitational-wave detectors

International Nuclear Information System (INIS)

Tinto, Massimo; Vallisneri, Michele; Armstrong, J.W.

2005-01-01

Space-borne interferometric gravitational-wave detectors, sensitive in the low-frequency (mHz) band, will fly in the next decade. In these detectors, the spacecraft-to-spacecraft light-travel times will necessarily be unequal and time varying, and (because of aberration) will have different values on up- and down-links. In such unequal-armlength interferometers, laser-phase noise will be canceled by taking linear combinations of the laser-phase observables measured between pairs of spacecraft, appropriately time shifted by the light propagation times along the corresponding arms. This procedure, known as time-delay interferometry (TDI), requires an accurate knowledge of the light-time delays as functions of time. Here we propose a high-accuracy technique to estimate these time delays, and we study its use in the context of the Laser Interferometer Space Antenna (LISA) mission. We refer to this ranging technique, which relies on the TDI combinations themselves, as time-delay interferometric ranging (TDIR). For every TDI combination, we show that, by minimizing the rms power in that combination (averaged over integration times ∼10 4 s) with respect to the time-delay parameters, we obtain estimates of the time delays accurate enough to cancel laser noise to a level well below the secondary noises. Thus TDIR allows the implementation of TDI without the use of dedicated interspacecraft ranging systems, with a potential simplification of the LISA design. In this paper we define the TDIR procedure formally, and we characterize its expected performance via simulations with the Synthetic LISA software package

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

Energy Technology Data Exchange (ETDEWEB)

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.

Methodology for lognormal modelling of malignant pleural mesothelioma survival time distributions: a study of 5580 case histories from Europe and USA

Energy Technology Data Exchange (ETDEWEB)

Mould, Richard F [41 Ewhurst Avenue, South Croydon, Surrey CR2 0DH (United Kingdom); Lahanas, Michael [Klinikum Offenbach, Strahlenklinik, 66 Starkenburgring, 63069 Offenbach am Main (Germany); Asselain, Bernard [Institut Curie, Biostatistiques, 26 rue d' Ulm, 75231 Paris Cedex 05 (France); Brewster, David [Director, Scottish Cancer Registry, Information Services (NHS National Services Scotland) Area 155, Gyle Square, 1 South Gyle Crescent, Edinburgh EH12 9EB (United Kingdom); Burgers, Sjaak A [Department of Thoracic Oncology, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The (Netherlands); Damhuis, Ronald A M [Rotterdam Cancer Registry, Rochussenstraat 125, PO Box 289, 3000 AG Rotterdam, The (Netherlands); Rycke, Yann De [Institut Curie, Biostatistiques, 26 rue d' Ulm, 75231 Paris Cedex 05 (France); Gennaro, Valerio [Liguria Mesothelioma Cancer Registry, Etiology and Epidemiology Department, National Cancer Research Institute, Pad. Maragliano, Largo R Benzi, 10-16132 Genoa (Italy); Szeszenia-Dabrowska, Neonila [Department of Occupational and Environmental Epidemiology, National Institute of Occupational Medicine, PO Box 199, Swietej Teresy od Dzieciatka Jezus 8, 91-348 Lodz (Poland)

2004-09-07

A truncated left-censored and right-censored lognormal model has been validated for representing pleural mesothelioma survival times in the range 5-200 weeks for data subsets grouped by age for males, 40-49, 50-59, 60-69, 70-79 and 80+ years and for all ages combined for females. The cases available for study were from Europe and USA and totalled 5580. This is larger than any other pleural mesothelioma cohort accrued for study. The methodology describes the computation of reference baseline probabilities, 5-200 weeks, which can be used in clinical trials to assess results of future promising treatment methods. This study is an extension of previous lognormal modelling by Mould et al (2002 Phys. Med. Biol. 47 3893-924) to predict long-term cancer survival from short-term data where the proportion cured is denoted by C and the uncured proportion, which can be represented by a lognormal, by (1 - C). Pleural mesothelioma is a special case when C = 0.

Methodology for lognormal modelling of malignant pleural mesothelioma survival time distributions: a study of 5580 case histories from Europe and USA

International Nuclear Information System (INIS)

Mould, Richard F; Lahanas, Michael; Asselain, Bernard; Brewster, David; Burgers, Sjaak A; Damhuis, Ronald A M; Rycke, Yann De; Gennaro, Valerio; Szeszenia-Dabrowska, Neonila

2004-01-01

A truncated left-censored and right-censored lognormal model has been validated for representing pleural mesothelioma survival times in the range 5-200 weeks for data subsets grouped by age for males, 40-49, 50-59, 60-69, 70-79 and 80+ years and for all ages combined for females. The cases available for study were from Europe and USA and totalled 5580. This is larger than any other pleural mesothelioma cohort accrued for study. The methodology describes the computation of reference baseline probabilities, 5-200 weeks, which can be used in clinical trials to assess results of future promising treatment methods. This study is an extension of previous lognormal modelling by Mould et al (2002 Phys. Med. Biol. 47 3893-924) to predict long-term cancer survival from short-term data where the proportion cured is denoted by C and the uncured proportion, which can be represented by a lognormal, by (1 - C). Pleural mesothelioma is a special case when C = 0

Time course of dynamic range adaptation in the auditory nerve

Science.gov (United States)

Wang, Grace I.; Dean, Isabel; Delgutte, Bertrand

2012-01-01

Auditory adaptation to sound-level statistics occurs as early as in the auditory nerve (AN), the first stage of neural auditory processing. In addition to firing rate adaptation characterized by a rate decrement dependent on previous spike activity, AN fibers show dynamic range adaptation, which is characterized by a shift of the rate-level function or dynamic range toward the most frequently occurring levels in a dynamic stimulus, thereby improving the precision of coding of the most common sound levels (Wen B, Wang GI, Dean I, Delgutte B. J Neurosci 29: 13797–13808, 2009). We investigated the time course of dynamic range adaptation by recording from AN fibers with a stimulus in which the sound levels periodically switch from one nonuniform level distribution to another (Dean I, Robinson BL, Harper NS, McAlpine D. J Neurosci 28: 6430–6438, 2008). Dynamic range adaptation occurred rapidly, but its exact time course was difficult to determine directly from the data because of the concomitant firing rate adaptation. To characterize the time course of dynamic range adaptation without the confound of firing rate adaptation, we developed a phenomenological “dual adaptation” model that accounts for both forms of AN adaptation. When fitted to the data, the model predicts that dynamic range adaptation occurs as rapidly as firing rate adaptation, over 100–400 ms, and the time constants of the two forms of adaptation are correlated. These findings suggest that adaptive processing in the auditory periphery in response to changes in mean sound level occurs rapidly enough to have significant impact on the coding of natural sounds. PMID:22457465

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

Science.gov (United States)

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.

Kidney transplant survival in pediatric and young adults

Directory of Open Access Journals (Sweden)

Acott Phil

2011-10-01

Full Text Available Abstract Background There is a perception that kidney transplant recipients transferred from pediatric centers to adult care have an increased risk of graft loss. It is not clear whether young adults transplanted in adult centers also suffer from high graft loss rates. Methods We examined death censored graft survival in 3 cohorts of young patients transplanted at a single center. Pediatric (PED patients transplanted at the pediatric center were compared to a cohort of young adults (YAD; age 18- Results In a multivariate Cox model for death-censored graft survival, PED survival was statistically similar to the YAD (HR 0.86, 95% CI 0.44, 1.7, p = 0.66, however the ADL cohort (HR 0.45, 95% CI 0.25, 0.82, p = 0.009 demonstrated better survival. Admitted non-adherence rates were not different among cohorts. Patients were transferred within a narrow age window (18.6 ± 1.0 age in years but at a wide range of times from the date of transplantation (5.1 ± 3.5 years and with a wide range of graft function (serum creatinine 182 ± 81 μmol/L. Conclusions The perception that pediatric transfers do poorly reflects advanced graft dysfunction in some at the time of transfer. The evidence also suggests that it is not the transfer of care that is the critical issue but rather recipients, somewhere between the ages of 11-14 and 25, are a unique and vulnerable cohort. Effective strategies to improve outcomes across this age group need to be identified and applied consistently.

Unsynchronized scanning with a low-cost laser range finder for real-time range imaging

Science.gov (United States)

Hatipoglu, Isa; Nakhmani, Arie

2017-06-01

Range imaging plays an essential role in many fields: 3D modeling, robotics, heritage, agriculture, forestry, reverse engineering. One of the most popular range-measuring technologies is laser scanner due to its several advantages: long range, high precision, real-time measurement capabilities, and no dependence on lighting conditions. However, laser scanners are very costly. Their high cost prevents widespread use in applications. Due to the latest developments in technology, now, low-cost, reliable, faster, and light-weight 1D laser range finders (LRFs) are available. A low-cost 1D LRF with a scanning mechanism, providing the ability of laser beam steering for additional dimensions, enables to capture a depth map. In this work, we present an unsynchronized scanning with a low-cost LRF to decrease scanning period and reduce vibrations caused by stop-scan in synchronized scanning. Moreover, we developed an algorithm for alignment of unsynchronized raw data and proposed range image post-processing framework. The proposed technique enables to have a range imaging system for a fraction of the price of its counterparts. The results prove that the proposed method can fulfill the need for a low-cost laser scanning for range imaging for static environments because the most significant limitation of the method is the scanning period which is about 2 minutes for 55,000 range points (resolution of 250x220 image). In contrast, scanning the same image takes around 4 minutes in synchronized scanning. Once faster, longer range, and narrow beam LRFs are available, the methods proposed in this work can produce better results.

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

Directory of Open Access Journals (Sweden)

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.

A systematic method for characterizing the time-range performance of ground penetrating radar

International Nuclear Information System (INIS)

Strange, A D

2013-01-01

The fundamental performance of ground penetrating radar (GPR) is linked to the ability to measure the signal time-of-flight in order to provide an accurate radar-to-target range estimate. Having knowledge of the actual time range and timing nonlinearities of a trace is therefore important when seeking to make quantitative range estimates. However, very few practical methods have been formally reported in the literature to characterize GPR time-range performance. This paper describes a method to accurately measure the true time range of a GPR to provide a quantitative assessment of the timing system performance and detect and quantify the effects of timing nonlinearity due to timing jitter. The effect of varying the number of samples per trace on the true time range has also been investigated and recommendations on how to minimize the effects of timing errors are described. The approach has been practically applied to characterize the timing performance of two commercial GPR systems. The importance of the method is that it provides the GPR community with a practical method to readily characterize the underlying accuracy of GPR systems. This in turn leads to enhanced target depth estimation as well as facilitating the accuracy of more sophisticated GPR signal processing methods. (paper)

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

Science.gov (United States)

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.

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

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

Effect of Migration Pathway on Travel Time and Survival of Acoustic-Tagged Juvenile Salmonids in the Columbia River Estuary

Energy Technology Data Exchange (ETDEWEB)

Harnish, Ryan A.; Johnson, Gary E.; McMichael, Geoffrey A.; Hughes, Michael S.; Ebberts, Blaine D.

2012-02-01

Off-channel areas (side channels, tidal flats, sand bars, and shallow-water bays) may serve as important migration corridors through estuarine environments for salmon and steelhead smolts. Relatively large percentages (21-33%) of acoustic-tagged yearling and subyearling Chinook salmon and steelhead smolts were detected migrating through off-channel areas of the Columbia River estuary in 2008. The probability of survival for off-channel migrants (0.78-0.94) was similar to or greater than the survival probability of main channel migrants (0.67-0.93). Median travel times were similar for all species or run types and migration pathways we examined, ranging from 1-2 d. The route used by smolts to migrate through the estuary may affect their vulnerability to predation. Acoustic-tagged steelhead that migrated nearest to avian predator nesting colonies experienced higher predation rates (24%) than those that migrated farthest from the colonies (10%). The use of multiple migration pathways may be advantageous to out-migrating smolts because it helps to buffer against high rates of mortality, which may occur in localized areas, and helps to minimize inter- and intraspecific competition.

Individual differences in long-range time representation.

Science.gov (United States)

Agostino, Camila S; Caetano, Marcelo S; Balci, Fuat; Claessens, Peter M E; Zana, Yossi

2017-04-01

On the basis of experimental data, long-range time representation has been proposed to follow a highly compressed power function, which has been hypothesized to explain the time inconsistency found in financial discount rate preferences. The aim of this study was to evaluate how well linear and power function models explain empirical data from individual participants tested in different procedural settings. The line paradigm was used in five different procedural variations with 35 adult participants. Data aggregated over the participants showed that fitted linear functions explained more than 98% of the variance in all procedures. A linear regression fit also outperformed a power model fit for the aggregated data. An individual-participant-based analysis showed better fits of a linear model to the data of 14 participants; better fits of a power function with an exponent β > 1 to the data of 12 participants; and better fits of a power function with β discount rates in intertemporal choice to the compressed nature of subjective time must entail the characterization of subjective time on an individual-participant basis.

Captive rearing technologies and survival of pheasants (Phasianus colchicus L. after release

Directory of Open Access Journals (Sweden)

Marco Bagliacca

2012-04-01

Full Text Available Studies have repeatedly emphasized the limited survival of pheasants reared using traditional methods compared to the wild one. For this reason we performed a field trial to compare survival rates, home ranges and habitat uses of pheasants artificial hatched and reared (traditional method with pheasants artificial hatched and reared by fostering mothers (hens. A total of 117 artificially hatched pheasants, 57 artificially brooded after hatch and 60 brooded by fostering hens, were equipped with a radio necklace tag or a poncho tag. Both groups were localized two-three times a week after their release in the wild. The survival rates of the brooded-by-hen pheasants showed an improvement of survival rates, either poncho or radio tagged (Pvs 57.1% and 35.0% vs 21.1%, respectively. The average maximum dispersion was 390 and 426 m and the home range were 12.0 and 11.6 ha in artificially brooded and brooded-by-hen pheasants, respectively. The land use showed that the woods were less represented than the available in the home range of every pheasant. For this reason the woods can be reduced in the agricultural areas interspersed with natural Mediterranean vegetation.

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

Science.gov (United States)

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.

Characterization of modulated time-of-flight range image sensors

Science.gov (United States)

Payne, Andrew D.; Dorrington, Adrian A.; Cree, Michael J.; Carnegie, Dale A.

2009-01-01

A number of full field image sensors have been developed that are capable of simultaneously measuring intensity and distance (range) for every pixel in a given scene using an indirect time-of-flight measurement technique. A light source is intensity modulated at a frequency between 10-100 MHz, and an image sensor is modulated at the same frequency, synchronously sampling light reflected from objects in the scene (homodyne detection). The time of flight is manifested as a phase shift in the illumination modulation envelope, which can be determined from the sampled data simultaneously for each pixel in the scene. This paper presents a method of characterizing the high frequency modulation response of these image sensors, using a pico-second laser pulser. The characterization results allow the optimal operating parameters, such as the modulation frequency, to be identified in order to maximize the range measurement precision for a given sensor. A number of potential sources of error exist when using these sensors, including deficiencies in the modulation waveform shape, duty cycle, or phase, resulting in contamination of the resultant range data. From the characterization data these parameters can be identified and compensated for by modifying the sensor hardware or through post processing of the acquired range measurements.

Precise Time Synchronisation and Ranging in Nano-Satellite Swarms

Science.gov (United States)

Laabs, Martin; Plettemeier, Dirk

2015-04-01

Precise time synchronization and ranging is very important for a variety of scientific experiments with more than two nano-satellites: For synthetic aperture radar (SAR) applications, for example, the radar signal phase (which corresponds to a synchronized time) as well as the location must be known on each satellite forming synthetic antenna. Also multi-static radar systems, MIMO radar systems or radio tomography applications will take advantage from highly accurate synchronization and position determination. We propose a method for synchronizing the time as well as measuring the distance between nano-satellites very precisely by utilizing mm-wave radio links. This approach can also be used for time synchronization of more than two satellites and accordingly determinating the precise relative location of nano-satellites in space. The time synchronization signal is modulated onto a mm-wave carrier. In the simplest form it is a harmonic sinusoidal signal with a frequency in the MHz range. The distance is measured with a frequency sweep or short pulse modulated onto a different carrier frequency. The sweep or pulse transmission start is synchronized to the received time synchronization. The time synchronization transmitter receives the pulse/sweep signal and can calculate the (double) time of flight for both signals. This measurement can be easily converted to the distance. The use of a mm-wave carrier leads to small antennas and the free space loss linked to the high frequency reduces non line of sight echoes. It also allows a high sweep/pulse bandwidth enabling superior ranging accuracy. Additionally, there is also less electromagnetic interference probability since telemetry and scientific applications typically do not use mm-wavefrequencies. Since the system is working full-duplex the time synchronization can be performed continuously and coherently. Up to now the required semiconductor processes did not achieve enough gain/bandwidth to realize this concept at

Environmental Survival of Mycobacterium avium subsp. paratuberculosis in Different Climatic Zones of Eastern Australia

Science.gov (United States)

Begg, Douglas J.; Dhand, Navneet K.; Watt, Bruce; Whittington, Richard J.

2014-01-01

The duration of survival of both the S and C strains of Mycobacterium avium subsp. paratuberculosis in feces was quantified in contrasting climatic zones of New South Wales, Australia, and detailed environmental temperature data were collected. Known concentrations of S and C strains in feces placed on soil in polystyrene boxes were exposed to the environment with or without the provision of shade (70%) at Bathurst, Armidale, Condobolin, and Broken Hill, and subsamples taken every 2 weeks were cultured for the presence of M. avium subsp. paratuberculosis. The duration of survival ranged from a minimum of 1 week to a maximum of 16 weeks, and the provision of 70% shade was the most important factor in extending the survival time. The hazard of death for exposed compared to shaded samples was 20 and 9 times higher for the S and C strains, respectively. Site did not affect the survival of the C strain, but for the S strain, the hazard of death was 2.3 times higher at the two arid zone sites (Broken Hill and Condobolin) than at the two temperate zone sites (Bathurst and Armidale). Temperature measurements revealed maximum temperatures exceeding 60°C and large daily temperature ranges at the soil surface, particularly in exposed boxes. PMID:24463974

Time-Correlated Single-Photon Counting Range Profiling of Moving Objects

Directory of Open Access Journals (Sweden)

Hedborg Julia

2016-01-01

TCSPC is a statistic method that requires an acquisition time and therefore the range profile of a non-stationary object (target may be corrupted. Here, we present results showing that it is possible to reconstruct the range profile of a moving target and calculate the velocity of the target.

Optical timing receiver for the NASA Spaceborne Ranging System. Part I. Dual peak-sensing timing discriminator

International Nuclear Information System (INIS)

Leskovar, B.; Lo, C.C.; Zizka, G.

1978-01-01

Position-resolution capabilities of the NASA Spaceborne Laser Ranging System are essentially determined by the time-resolution capabilities of its optical timing receiver. The optical timing receiver consists of a fast photoelectric device; (e.g., photomultiplier or an avalanche photodiode detector), a timing discriminator, a high-precision event-timing digitizer, and a signal-processing system. The time-resolution capabilities of the receiver are determined by the photoelectron time spread of the photoelectric device, the time walk and resolution characteristics of the timing discriminator, and the resolution of the event-timing digitizer. It is thus necessary to evaluate available fast photoelectronic devices with respect to their time-resolution capabilities, to design a very low time walk timing discriminator and to develop a high-resolution event-timing digitizer which will be used in the high-resolution spaceborne laser ranging system receiver. The development of a new dual-peak sensing timing discriminator is described. The amplitude dependent time walk is less than +-150 psec for a 100:1 dynamic range of Gaussian-shaped input signals having pulse widths between 11 and 17 nsec. The unit produces 800 mV negative output pulses, each 10 nsec wide, and 3V positive pulses with widths of 15 nsec. The time delay through the discriminator is approximately 37 nsec. In this discriminator the input signal is processed by a peak-crossing circuit which produces a bipolar pulse having its zero-crossing point at the peak of the input signal. All essential functions in the discriminator are performed by means of tunnel diodes with backward diodes as nonlinear loads. The discriminator is designed to be CAMAC compatible to a conventional time-interval unit or a high-precision event timing digitizer. The adjustment procedure for obtaining minimum time walk is also given

Time biases in laser ranging observations: A concerning issue of Space Geodesy

Science.gov (United States)

Exertier, Pierre; Belli, A.; Lemoine, J. M.

2017-09-01

Time transfer by Laser Ranging (LR) recently demonstrated a remarkable stability (a few ps over ∼1000 s) and accuracy (synchronizing both space and ground clocks over distances from a few thousands to tens of thousands kilometers. Given its potential role in navigation, fundamental physics and metrology, it is crucial that synergy between laser ranging and Time&Frequency (T/F) technologies improves to meet the present and future space geodesy requirements. In this article, we examine the behavior of T/F systems that are used in LR tracking stations of the international laser ranging service. The approach we investigate is to compute time synchronization between clocks used at LR stations using accurate data of the Time Transfer by Laser Link (T2L2) experiment onboard the satellite Jason-2 (Samain et al., 2014). Systematic time biases are estimated against the UTC time scale for a set of 22 observing stations in 2013, in the range of zero to a few μ s. Our results suggest that the ILRS network suffers from accuracy issues, due to time biases in the laser ranging observations. We discuss how these systematic effects impact the precise orbit determination of LAGEOS geodetic satellites over a 1-year analysis, and additionally give a measure of the local effect into station coordinates, regarding in particular the effect in the east-west component that is of 2-6 mm for a typical systematic time bias of one μ s.

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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

Splenectomy increases the survival time of heart allograft via developing immune tolerance

Science.gov (United States)

2013-01-01

Background The spleen is an active lymphoid organ. The effect of splenectomy on the immune response remains unclear. This study investigated whether splenectomy can induce immune tolerance and has a beneficial role in cardiac allograft. Methods Wistar rats were used for heart donors. The Sprague–Dawley (SD) rats designated as the recipients of heart transplantation (HT) were randomly assigned into four groups: sham, splenectomy, HT, splenectomy + HT. The survival of transplanted hearts was assessed by daily checking of abdominal palpation. At various time points after transplantation, the transplanted hearts were collected and histologically examined; the level of CD4+CD25+ T regulatory lymphocytes (Tregs) and rate of lymphocyte apoptosis (annexin-v+ PI+ cells) in the blood were analyzed by using flow cytometric method. Results 1) Splenectomy significantly prolonged the mean survival time of heart allografts (7 ± 1.1 days and 27 ± 1.5 days for HT and splenectomy + HT, respectively; n = 12-14/group, HT vs. splenectomy + HT, p Splenectomy delayed pathological changes (inflammatory cell infiltration, myocardial damage) of the transplanted hearts in splenectomy + HT rats; 3) The level of CD4+CD25+ Tregs in the blood of splenectomized rats was significantly increased within 7 days (2.4 ± 0.5%, 4.9 ± 1.3% and 5.3 ± 1.0% for sham, splenectomy and splenectomy + HT, respectively; n = 15/group, sham vs. splenectomy or splenectomy + HT, p splenectomy surgery and gradually decreased to baseline level; 4) Splenectomy increased the rate of lymphocyte apoptosis (day 7: 0.3 ± 0.05%, 3.9 ± 0.9% and 4.1 ± 0.9% for sham, splenectomy and splenectomy + HT, respectively; n = 15/group, sham vs. splenectomy or splenectomy + HT, p Splenectomy inhibits the development of pathology and prolongs the survival time of cardiac allograft. The responsible mechanism is associated with induction of immune

Optical timing receiver for the NASA Spaceborne Ranging System. Part II: high precision event-timing digitizer

Energy Technology Data Exchange (ETDEWEB)

Leskovar, Branko; Turko, Bojan

1978-08-01

Position-resolution capabilities of the NASA Spaceborne Laser Ranging System are essentially determined by the timeresolution capabilities of its optical timing receiver. The optical timing receiver consists of a fast photoelectric device; (e.g., photomultiplier or an avalanche photodiode detector), a timing discriminator, a high-precision event-timing digitizer, and a signal-processing system. The time-resolution capabilities of the receiver are determined by the photoelectron time spread of the photoelectric device, the time walk and resolution characteristics of the timing discriminator, and the resolution of the event-timing digitizer. It is thus necessary to evaluate available fast photoelectronic devices with respect to the time-resolution capabilities, and to develop a very low time walk timing discriminator and a high-resolution event-timing digitizer to be used in the high-resolution spaceborne laser ranging system receiver. This part of the report describes the development of a high precision event-timing digitizer. The event-timing digitizer is basically a combination of a very accurate high resolution real time digital clock and an interval timer. The timing digitizer is a high resolution multiple stop clock, counting the time up to 131 days in 19.5 ps increments.

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.

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.)

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

Directory of Open Access Journals (Sweden)

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.

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.

Two-way laser ranging and time transfer experiments between LOLA and an Earth-based satellite laser ranging station

Science.gov (United States)

Mao, D.; Sun, X.; Neumann, G. A.; Barker, M. K.; Mazarico, E. M.; Hoffman, E.; Zagwodzki, T. W.; Torrence, M. H.; Mcgarry, J.; Smith, D. E.; Zuber, M. T.

2017-12-01

Satellite Laser Ranging (SLR) has established time-of-flight measurements with mm precision to targets orbiting the Earth and the Moon using single-ended round-trip laser ranging to passive optical retro-reflectors. These high-precision measurements enable advances in fundamental physics, solar system dynamics. However, the received signal strength suffers from a 1/R4 decay, which makes it impractical for measuring distances beyond the Moon's orbit. On the other hand, for a two-way laser transponder pair, where laser pulses are both transmitted to and received from each end of the laser links, the signal strength at both terminals only decreases by 1/R2, thus allowing a greater range of distances to be covered. The asynchronous transponder concept has been previously demonstrated by a test in 2005 between the Mercury Laser Altimeter (MLA) aboard the MESSENGER (MErcury Surface, Space ENvironment, Geochemistry, and Ranging) spacecraft and NASA's Goddard Geophysical and Astronomical Observatory (GGAO) at a distance of ˜0.16 AU. In October 2013, regular two-way transponder-type range measurements were obtained over 15 days between the Lunar Laser Communication Demonstration (LLCD) aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft and NASA's ground station at White Sands, NM. The Lunar Orbiter Laser Altimeter (LOLA) aboard the Lunar Reconnaissance Orbiter (LRO) provides us a unique capability to test time-transfer beyond near Earth orbit. Here we present results from two-way transponder-type experiments between LOLA and GGAO conducted in March 2014 and 2017. As in the time-transfer by laser link (T2L2) experiments between a ground station and an earth-orbiting satellite, LOLA and GGAO ranged to each other simultaneously in these two-way tests at lunar distance. We measured the time-of-flight while cross-referencing the spacecraft clock to the ground station time. On May 4th, 2017, about 20 minutes of two-way measurements were collected. The

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.

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

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

Mechanisms and mediation in survival analysis: towards an integrated analytical framework

Directory of Open Access Journals (Sweden)

Jonathan Pratschke

2016-02-01

Full Text Available Abstract Background A wide-ranging debate has taken place in recent years on mediation analysis and causal modelling, raising profound theoretical, philosophical and methodological questions. The authors build on the results of these discussions to work towards an integrated approach to the analysis of research questions that situate survival outcomes in relation to complex causal pathways with multiple mediators. The background to this contribution is the increasingly urgent need for policy-relevant research on the nature of inequalities in health and healthcare. Methods The authors begin by summarising debates on causal inference, mediated effects and statistical models, showing that these three strands of research have powerful synergies. They review a range of approaches which seek to extend existing survival models to obtain valid estimates of mediation effects. They then argue for an alternative strategy, which involves integrating survival outcomes within Structural Equation Models via the discrete-time survival model. This approach can provide an integrated framework for studying mediation effects in relation to survival outcomes, an issue of great relevance in applied health research. The authors provide an example of how these techniques can be used to explore whether the social class position of patients has a significant indirect effect on the hazard of death from colon cancer. Results The results suggest that the indirect effects of social class on survival are substantial and negative (-0.23 overall. In addition to the substantial direct effect of this variable (-0.60, its indirect effects account for more than one quarter of the total effect. The two main pathways for this indirect effect, via emergency admission (-0.12, on the one hand, and hospital caseload, on the other, (-0.10 are of similar size. Conclusions The discrete-time survival model provides an attractive way of integrating time-to-event data within the field of

Mechanisms and mediation in survival analysis: towards an integrated analytical framework.

Science.gov (United States)

Pratschke, Jonathan; Haase, Trutz; Comber, Harry; Sharp, Linda; de Camargo Cancela, Marianna; Johnson, Howard

2016-02-29

A wide-ranging debate has taken place in recent years on mediation analysis and causal modelling, raising profound theoretical, philosophical and methodological questions. The authors build on the results of these discussions to work towards an integrated approach to the analysis of research questions that situate survival outcomes in relation to complex causal pathways with multiple mediators. The background to this contribution is the increasingly urgent need for policy-relevant research on the nature of inequalities in health and healthcare. The authors begin by summarising debates on causal inference, mediated effects and statistical models, showing that these three strands of research have powerful synergies. They review a range of approaches which seek to extend existing survival models to obtain valid estimates of mediation effects. They then argue for an alternative strategy, which involves integrating survival outcomes within Structural Equation Models via the discrete-time survival model. This approach can provide an integrated framework for studying mediation effects in relation to survival outcomes, an issue of great relevance in applied health research. The authors provide an example of how these techniques can be used to explore whether the social class position of patients has a significant indirect effect on the hazard of death from colon cancer. The results suggest that the indirect effects of social class on survival are substantial and negative (-0.23 overall). In addition to the substantial direct effect of this variable (-0.60), its indirect effects account for more than one quarter of the total effect. The two main pathways for this indirect effect, via emergency admission (-0.12), on the one hand, and hospital caseload, on the other, (-0.10) are of similar size. The discrete-time survival model provides an attractive way of integrating time-to-event data within the field of Structural Equation Modelling. The authors demonstrate the efficacy

Time-of-flight range imaging for underwater applications

Science.gov (United States)

Merbold, Hannes; Catregn, Gion-Pol; Leutenegger, Tobias

2018-02-01

Precise and low-cost range imaging in underwater settings with object distances on the meter level is demonstrated. This is addressed through silicon-based time-of-flight (TOF) cameras operated with light emitting diodes (LEDs) at visible, rather than near-IR wavelengths. We find that the attainable performance depends on a variety of parameters, such as the wavelength dependent absorption of water, the emitted optical power and response times of the LEDs, or the spectral sensitivity of the TOF chip. An in-depth analysis of the interplay between the different parameters is given and the performance of underwater TOF imaging using different visible illumination wavelengths is analyzed.

Slow Freezing or Vitrification of Oocytes: Their Effects on Survival and Meiotic Spindles, and the Time Schedule for Clinical Practice

Directory of Open Access Journals (Sweden)

Shee-Uan Chen

2009-03-01

Full Text Available Both the slow-freezing method with increased sucrose concentration and new vitrification techniques significantly improve the results of cryopreservation of human oocytes. The recent perfection for vitrification includes the concepts of increase of cooling and warming rates using minimum volume methods, and decrease of toxicity by reducing the concentration of cryoprotectants. In the recent literature, the survival of cryopreserved oocytes ranged from 74% to 90% using the slow-freezing method and from 84% to 99% by vitrification. Overall, the survival rate of oocytes from vitrification (95%, 899/948 appeared higher than that of the slow-freezing method (75%, 1,275/1,683. The microtubules of meiotic spindles are vulnerable to the thermal changes and will depolymerize. After incubation, the microtubules repolymerize. Spindle recovery is faster after vitrification than slow freezing. Even so, after 3 hours of incubation, spindle recuperation is similar between vitrification and slow freezing. Considering both aspects of spindle recovery and oocyte aging, the time schedule for oocyte cryopreservation program makes fertilization in the optimal time. Intracytoplasmic sperm injection is performed for oocytes at 3 hours of post-thaw incubation from the slow-freezing method and 2 hours from vitrification, with restoration of meiotic spindles. The pregnancy potential of cryopreserved oocytes is comparable to that of fresh oocytes or frozen embryos. Cryopreservation of oocytes would importantly contribute to oocyte donation and preservation of fertility for cancer patients.

Inferring the colonization of a mountain range--refugia vs. nunatak survival in high alpine ground beetles.

Science.gov (United States)

Lohse, Konrad; Nicholls, James A; Stone, Graham N

2011-01-01

It has long been debated whether high alpine specialists survived ice ages in situ on small ice-free islands of habitat, so-called nunataks, or whether glacial survival was restricted to larger massifs de refuge at the periphery. We evaluate these alternative hypotheses in a local radiation of high alpine carabid beetles (genus Trechus) in the Orobian Alps, Northern Italy. While summits along the northern ridge of this mountain range were surrounded by the icesheet as nunataks during the last glacial maximum, southern areas remained unglaciated. We analyse a total of 1366 bp of mitochondrial (Cox1 and Cox2) data sampled from 150 individuals from twelve populations and 530 bp of nuclear (PEPCK) sequence sampled for a subset of 30 individuals. Using Bayesian inference, we estimate ancestral location states in the gene trees, which in turn are used to infer the most likely order of recolonization under a model of sequential founder events from a massif de refuge from the mitochondrial data. We test for the paraphyly expected under this model and for reciprocal monophyly predicted by a contrasting model of prolonged persistence of nunatak populations. We find that (i) only three populations are incompatible with the paraphyly of the massif de refuge model, (ii) both mitochondrial and nuclear data support separate refugial origins for populations on the western and eastern ends of the northern ridge, and (iii) mitochondrial node ages suggest persistence on the northern ridge for part of the last ice age. © 2010 Blackwell Publishing Ltd.

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

Science.gov (United States)

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?

Transgastric pure-NOTES peritoneoscopy and endoscopic ultrasonography for staging of gastrointestinal cancers: a survival and feasibility study.

Science.gov (United States)

Donatsky, Anders Meller; Vilmann, Peter; Meisner, Søren; Jørgensen, Lars Nannestad; Rosenberg, Jacob

2012-06-01

Human natural orifice transluminal endoscopic surgery (NOTES) has mainly been based on simultaneous laparoscopic assistance (hybrid NOTES), forgoing the theoretical benefits of the NOTES technique. This is due to a lack of NOTES-specific instruments and endoscopes, making pure-NOTES procedures difficult and time consuming. An area where pure NOTES could be adopted at its present stage of development is minimally invasive staging of gastrointestinal (GI) cancer. The aim of this study is to evaluate the feasibility of combining transgastric (TG) pure-NOTES peritoneoscopy and intraperitoneal endoscopic ultrasonography (ip-EUS) with intraluminal EUS (il-EUS) for peritoneal evaluation. This was a feasibility and survival study where il-EUS followed by ip-EUS and peritoneoscopy was performed in 10 pigs subjected to TG pure NOTES. A score was given with regard to achieved visualisation of predefined anatomical structures. Survival was assessed at postoperative day (POD) 14. All animals survived until POD 14. Median total procedural time was 94 min (range 74-130 min). Median time for il-EUS, ip-EUS and peritoneoscopy was 11 min (range 7-14 min), 13 min (range 8-20 min) and 10 min (range 6-23 min). Il-EUS, ip-EUS and peritoneoscopy resulted in a score of 15/15 points (range 14-15 points), 6/9 points (range 1-8 points) and 12/13 points (range 8-13 points). TG pure-NOTES peritoneoscopy and ip-EUS combined with il-EUS is feasible and provides sufficient peritoneal evaluation. The technique could have potential for minimally invasive staging of GI cancers.

Thresholds and timing of pre-operative thrombocytosis and ovarian cancer survival: analysis of laboratory measures from electronic medical records

International Nuclear Information System (INIS)

Cozzi, Gabriella D.; Samuel, Jacob M.; Fromal, Jason T.; Keene, Spencer; Crispens, Marta A.; Khabele, Dineo; Beeghly-Fadiel, Alicia

2016-01-01

Thrombocytosis has been associated with poor ovarian cancer prognosis. However, comparisons of thresholds to define thrombocytosis and evaluation of relevant timing of platelet measurement has not been previously conducted. We selected Tumor Registry confirmed ovarian, primary peritoneal, and fallopian tube cancer cases diagnosed between 1995–2013 from the Vanderbilt University Medical Center. Laboratory measured platelet values from electronic medical records (EMR) were used to determine thrombocytosis at three thresholds: a platelet count greater than 350, 400, or 450 × 10 9 /liter. Timing was evaluated with 5 intervals: on the date of diagnosis, and up to 1, 2, 4, and 8 weeks prior to the date of diagnosis. Cox regression was used to calculate hazard ratios (HR) and confidence intervals (CI) for association with overall survival; adjustment included age, stage, grade, and histologic subtype of disease. Pre-diagnosis platelet measures were available for 136, 241, 280, 297, and 304 cases in the five intervals. The prevalence of thrombocytosis decreased with increasing thresholds and was generally consistent across the five time intervals, ranging from 44.8–53.2 %, 31.6–39.4 %, and 19.9–26.1 % across the three thresholds. Associations with higher grade and stage of disease gained significance as the threshold increased. With the exception of the lowest threshold on the date of diagnosis (HR 350 : 1.55, 95 % CI: 0.97–2.47), all other survival associations were significant, with the highest reaching twice the risk of death for thrombocytosis on the date of diagnosis (HR 400 : 2.01, 95 % CI: 1.25–3.23). Our EMR approach yielded associations comparable to published findings from medical record abstraction approaches. In addition, our results indicate that lower thrombocytosis thresholds and platelet measures up to 8 weeks before diagnosis may inform ovarian cancer characteristics and prognosis

Real-time range acquisition by adaptive structured light.

Science.gov (United States)

Koninckx, Thomas P; Van Gool, Luc

2006-03-01

The goal of this paper is to provide a "self-adaptive" system for real-time range acquisition. Reconstructions are based on a single frame structured light illumination. Instead of using generic, static coding that is supposed to work under all circumstances, system adaptation is proposed. This occurs on-the-fly and renders the system more robust against instant scene variability and creates suitable patterns at startup. A continuous trade-off between speed and quality is made. A weighted combination of different coding cues--based upon pattern color, geometry, and tracking--yields a robust way to solve the correspondence problem. The individual coding cues are automatically adapted within a considered family of patterns. The weights to combine them are based on the average consistency with the result within a small time-window. The integration itself is done by reformulating the problem as a graph cut. Also, the camera-projector configuration is taken into account for generating the projection patterns. The correctness of the range maps is not guaranteed, but an estimation of the uncertainty is provided for each part of the reconstruction. Our prototype is implemented using unmodified consumer hardware only and, therefore, is cheap. Frame rates vary between 10 and 25 fps, dependent on scene complexity.

Acoustic time-of-flight for proton range verification in water

Energy Technology Data Exchange (ETDEWEB)

Jones, Kevin C.; Avery, Stephen, E-mail: Stephen.Avery@uphs.upenn.edu [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Vander Stappen, François [Ion Beam Applications SA, Louvain-la-Neuve 1348 (Belgium); Sehgal, Chandra M. [Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

2016-09-15

Purpose: Measurement of the arrival times of thermoacoustic waves induced by pulsed proton dose depositions (protoacoustics) may provide a proton range verification method. The goal of this study is to characterize the required dose and protoacoustic proton range (distance) verification accuracy in a homogeneous water medium at a hospital-based clinical cyclotron. Methods: Gaussian-like proton pulses with 17 μs widths and instantaneous currents of 480 nA (5.6 × 10{sup 7} protons/pulse, 3.4 cGy/pulse at the Bragg peak) were generated by modulating the cyclotron proton source with a function generator. After energy degradation, the 190 MeV proton pulses irradiated a water phantom, and the generated protoacoustic emissions were measured by a hydrophone. The detector position and proton pulse characteristics were varied. The experimental results were compared to simulations. Different arrival time metrics derived from acoustic waveforms were compared, and the accuracy of protoacoustic time-of-flight distance calculations was assessed. Results: A 27 mPa noise level was observed in the treatment room during irradiation. At 5 cm from the proton beam, an average maximum pressure of 5.2 mPa/1 × 10{sup 7} protons (6.1 mGy at the Bragg peak) was measured after irradiation with a proton pulse with 10%–90% rise time of 11 μs. Simulation and experiment arrival times agreed well, and the observed 2.4 μs delay between simulation and experiment is attributed to the difference between the hydrophone’s acoustic and geometric centers. Based on protoacoustic arrival times, the beam axis position was measured to within (x, y) = (−2.0,  0.5) ± 1 mm. After deconvolution of the exciting proton pulse, the protoacoustic compression peak provided the most consistent measure of the distance to the Bragg peak, with an error distribution with mean = − 4.5 mm and standard deviation = 2.0 mm. Conclusions: Based on water tank measurements at a clinical hospital-based cyclotron

Biostatistics series module 9: Survival analysis

Directory of Open Access Journals (Sweden)

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.

Science.gov (United States)

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

SURVIVAL ANALYSIS AND LENGTH-BIASED SAMPLING

Directory of Open Access Journals (Sweden)

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.

Optimal Frequency Ranges for Sub-Microsecond Precision Pulsar Timing

Science.gov (United States)

Lam, Michael Timothy; McLaughlin, Maura; Cordes, James; Chatterjee, Shami; Lazio, Joseph

2018-01-01

Precision pulsar timing requires optimization against measurement errors and astrophysical variance from the neutron stars themselves and the interstellar medium. We investigate optimization of arrival time precision as a function of radio frequency and bandwidth. We find that increases in bandwidth that reduce the contribution from receiver noise are countered by the strong chromatic dependence of interstellar effects and intrinsic pulse-profile evolution. The resulting optimal frequency range is therefore telescope and pulsar dependent. We demonstrate the results for five pulsars included in current pulsar timing arrays and determine that they are not optimally observed at current center frequencies. We also find that arrival-time precision can be improved by increases in total bandwidth. Wideband receivers centered at high frequencies can reduce required overall integration times and provide significant improvements in arrival time uncertainty by a factor of $\\sim$$\\sqrt{2}$ in most cases, assuming a fixed integration time. We also discuss how timing programs can be extended to pulsars with larger dispersion measures through the use of higher-frequency observations.

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

Directory of Open Access Journals (Sweden)

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

Bronchoscopic management of patients with symptomatic airway stenosis and prognostic factors for survival.

Science.gov (United States)

Okiror, Lawrence; Jiang, Li; Oswald, Nicola; Bille, Andrea; Rajesh, Pala; Bishay, Ehab; Steyn, Richard; Naidu, Babu; Kalkat, Maninder

2015-05-01

Interventional bronchoscopy is effective in the management of patients with symptomatic airway obstruction for both malignant and benign conditions. The main aim of this study is to report our experience with emergency interventional bronchoscopy in patients with symptomatic airway obstruction and identify prognostic factors for survival. This is a retrospective observational study of patients undergoing emergency interventional bronchoscopy over a 4-year period. Survival times were analyzed separately for patients with benign and malignant airway obstruction by the Kaplan-Meier method. Between June 2009 and July 2013, 168 emergency interventional bronchoscopies were performed in 112 patients for airway obstruction. The median age was 63 years (range, 20 to 86), and 91 patients (54%) patients were female. Seventy-two cases (43%) had airway obstruction due to malignant disease. There were 3 in-hospital deaths (2.7%). Median survival of the study population was 5.6 months (range, 0 to 51) with a median follow-up of 7.3 months (range, 0 to 51). Median survival for patients with malignant airway obstruction was 3.5 months (range, 0 to 21), and 9.8 months (range, 0.1 to 51) for those with benign disease. Airway intervention facilitated palliative chemotherapy in 32 patients (44%) of those with malignant airway obstruction. At multivariate analysis in patients with malignant airway obstruction, presence of stridor (hazard ratio 1.919, 95% confidence interval: 1.082 to 3.404, p = 0.026) and not receiving postprocedure chemotherapy (hazard ratio 2.05, 95% confidence interval: 1.156 to 3.636, p = 0.014) were independent prognostic factors for death. Emergency interventional bronchoscopy for airway obstruction is safe, relieved symptoms, and facilitated palliative chemotherapy, which improved survival. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Survival in 76 cats with epilepsy of unknown cause: a retrospective study.

Science.gov (United States)

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.

Does the benefit on survival from leisure time physical activity depend on physical activity at work? A prospective cohort study.

Directory of Open Access Journals (Sweden)

Andreas Holtermann

Full Text Available PURPOSE: To investigate if persons with high physical activity at work have the same benefits from leisure time physical activity as persons with sedentary work. METHODS: In the Copenhagen City Heart Study, a prospective cohort of 7,411 males and 8,916 females aged 25-66 years without known cardiovascular disease at entry in 1976-78, 1981-83, 1991-94, or 2001-03, the authors analyzed with sex-stratified multivariate Cox proportional hazards regression the association between leisure time physical activity and cardiovascular and all-cause mortality among individuals with different levels of occupational physical activity. RESULTS: During a median follow-up of 22.4 years, 4,003 individuals died from cardiovascular disease and 8,935 from all-causes. Irrespective of level of occupational physical activity, a consistently lower risk with increasing leisure time physical activity was found for both cardiovascular and all-cause mortality among both men and women. Compared to low leisure time physical activity, the survival benefit ranged from 1.5-3.6 years for moderate and 2.6-4.7 years for high leisure time physical activity among the different levels of occupational physical activity. CONCLUSION: Public campaigns and initiatives for increasing physical activity in the working population should target everybody, irrespective of physical activity at work.

Does the benefit on survival from leisure time physical activity depend on physical activity at work? A prospective cohort study.

Science.gov (United States)

Holtermann, Andreas; Marott, Jacob Louis; Gyntelberg, Finn; Søgaard, Karen; Suadicani, Poul; Mortensen, Ole Steen; Prescott, Eva; Schnohr, Peter

2013-01-01

To investigate if persons with high physical activity at work have the same benefits from leisure time physical activity as persons with sedentary work. In the Copenhagen City Heart Study, a prospective cohort of 7,411 males and 8,916 females aged 25-66 years without known cardiovascular disease at entry in 1976-78, 1981-83, 1991-94, or 2001-03, the authors analyzed with sex-stratified multivariate Cox proportional hazards regression the association between leisure time physical activity and cardiovascular and all-cause mortality among individuals with different levels of occupational physical activity. During a median follow-up of 22.4 years, 4,003 individuals died from cardiovascular disease and 8,935 from all-causes. Irrespective of level of occupational physical activity, a consistently lower risk with increasing leisure time physical activity was found for both cardiovascular and all-cause mortality among both men and women. Compared to low leisure time physical activity, the survival benefit ranged from 1.5-3.6 years for moderate and 2.6-4.7 years for high leisure time physical activity among the different levels of occupational physical activity. Public campaigns and initiatives for increasing physical activity in the working population should target everybody, irrespective of physical activity at work.

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

Science.gov (United States)

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.

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.

Understanding survival analysis: Kaplan-Meier estimate.

Science.gov (United States)

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.

IceBridge Riegl Laser Altimeter L1B Time-Tagged Laser Ranges

Data.gov (United States)

National Aeronautics and Space Administration — The NASA IceBridge Riegl Laser Altimeter L1B Time-Tagged Laser Ranges (ILUTP1B) data set contains laser ranges, returned pulses, and deviation for returned pulses in...

Time Biases in laser ranging measurements; impacts on geodetic products (Reference Frame and Orbitography)

Science.gov (United States)

Belli, A.; Exertier, P.; Lemoine, F. G.; Chinn, D. S.; Zelensky, N. P.

2017-12-01

The GGOS objectives are to maintain a geodetic network with an accuracy of 1 mm and a stability of 0.1 mm per year. For years, the laser ranging technique, which provide very accurate absolute distances to geodetic targets enable to determine the scale factor as well as coordinates of the geocenter. In order to achieve this goal, systematic errors appearing in the laser ranging measurements must be considered and solved. In addition to Range Bias (RB), which is the primary source of uncertainty of the technique, Time Bias (TB) has been recently detected by using the Time Transfer by Laser Link (T2L2) space instrument capability on-board the satellite Jason-2. Instead of determining TB through the precise orbit determination that is applied to commonly used geodetic targets like LAGEOS to estimate global geodetic products, we have developed, independently, a dedicated method to transfer time between remote satellite laser ranging stations. As a result, the evolving clock phase shift to UTC of around 30 stations has been determined under the form of time series of time bias per station from 2008 to 2016 with an accuracy of 3-4 ns. It demonstrated the difficulty, in terms of Time & Frequency used technologies, to locally maintain accuracy and long term stability at least in the range of 100 ns that is the current requirement for time measurements (UTC) for the laser ranging technique. Because some laser ranging stations oftently exceed this limit (from 100 ns to a few μs) we have been studying these effects first on the precision orbit determination itself, second on the station positioning. We discuss the impact of TB on LAGEOS and Jason-2 orbits, which appears to affect the along-track component essentially. We also investigate the role of TB in global geodetic parameters as the station coordinates. Finally, we propose to provide the community with time series of time bias of laser ranging stations, under the form of a data- handling-file in order to be included in

Western aeronautical test range real-time graphics software package MAGIC

Science.gov (United States)

Malone, Jacqueline C.; Moore, Archie L.

1988-01-01

The master graphics interactive console (MAGIC) software package used on the Western Aeronautical Test Range (WATR) of the NASA Ames Research Center is described. MAGIC is a resident real-time research tool available to flight researchers-scientists in the NASA mission control centers of the WATR at the Dryden Flight Research Facility at Edwards, California. The hardware configuration and capabilities of the real-time software package are also discussed.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Time-reversed lasing in the terahertz range and its preliminary study in sensor applications

Energy Technology Data Exchange (ETDEWEB)

Shen, Yun, E-mail: shenyunoptics@gmail.com [Department of Physics, Nanchang University, Nanchang 330031 (China); Liu, Huaqing [Department of Physics, Nanchang University, Nanchang 330031 (China); Deng, Xiaohua [Institute of Space Science and Technology, Nanchang University, Nanchang 330031 (China); Wang, Guoping [Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 (China)

2017-02-05

Time-reversed lasing in a uniform slab and a grating structure are investigated in the terahertz range. The results show that both the uniform slab and grating can support terahertz time-reversed lasing. Nevertheless, due to the tunable effective refractive index, the grating structure can not only exhibit time-reversed lasing more effectively and flexibly than a uniform slab, but also can realize significant absorption in a broader operating frequency range. Furthermore, applications of terahertz time-reversed lasing for novel concentration/thickness sensors are preliminarily studied in a single-channel coherent perfect absorber system. - Highlights: • Time-reversed lasing are investigated in the terahertz range. • The grating structure exhibit time-reversed lasing more effectively and flexibly than a uniform slab. • THz time-reversed lasing for novel concentration/thickness sensors are studied.

Deep learning predictions of survival based on MRI in amyotrophic lateral sclerosis.

Science.gov (United States)

van der Burgh, Hannelore K; Schmidt, Ruben; Westeneng, Henk-Jan; de Reus, Marcel A; van den Berg, Leonard H; van den Heuvel, Martijn P

2017-01-01

Amyotrophic lateral sclerosis (ALS) is a progressive neuromuscular disease, with large variation in survival between patients. Currently, it remains rather difficult to predict survival based on clinical parameters alone. Here, we set out to use clinical characteristics in combination with MRI data to predict survival of ALS patients using deep learning, a machine learning technique highly effective in a broad range of big-data analyses. A group of 135 ALS patients was included from whom high-resolution diffusion-weighted and T1-weighted images were acquired at the first visit to the outpatient clinic. Next, each of the patients was monitored carefully and survival time to death was recorded. Patients were labeled as short, medium or long survivors, based on their recorded time to death as measured from the time of disease onset. In the deep learning procedure, the total group of 135 patients was split into a training set for deep learning (n = 83 patients), a validation set (n = 20) and an independent evaluation set (n = 32) to evaluate the performance of the obtained deep learning networks. Deep learning based on clinical characteristics predicted survival category correctly in 68.8% of the cases. Deep learning based on MRI predicted 62.5% correctly using structural connectivity and 62.5% using brain morphology data. Notably, when we combined the three sources of information, deep learning prediction accuracy increased to 84.4%. Taken together, our findings show the added value of MRI with respect to predicting survival in ALS, demonstrating the advantage of deep learning in disease prognostication.

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.

Multi-configuration time-dependent density-functional theory based on range separation

DEFF Research Database (Denmark)

Fromager, E.; Knecht, S.; Jensen, Hans Jørgen Aagaard

2013-01-01

Multi-configuration range-separated density-functional theory is extended to the time-dependent regime. An exact variational formulation is derived. The approximation, which consists in combining a long-range Multi-Configuration- Self-Consistent Field (MCSCF) treatment with an adiabatic short...... (srGGA) approximations. As expected, when modeling long-range interactions with the MCSCF model instead of the adiabatic Buijse-Baerends density-matrix functional as recently proposed by Pernal [J. Chem. Phys. 136, 184105 (2012)10.1063/1.4712019], the description of both the 1D doubly-excited state...

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.

Ship Systems Survivability Test Site

Data.gov (United States)

Federal Laboratory Consortium — Area for testing survivability of shipboard systems to include electrical, communications, and fire suppression. Multipurpose test range for supporting gun firing,...

Determinants of IPO survival on the Johannesburg securities exchange

Directory of Open Access Journals (Sweden)

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

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

Science.gov (United States)

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.

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

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.

A better understanding of long-range temporal dependence of traffic flow time series

Science.gov (United States)

Feng, Shuo; Wang, Xingmin; Sun, Haowei; Zhang, Yi; Li, Li

2018-02-01

Long-range temporal dependence is an important research perspective for modelling of traffic flow time series. Various methods have been proposed to depict the long-range temporal dependence, including autocorrelation function analysis, spectral analysis and fractal analysis. However, few researches have studied the daily temporal dependence (i.e. the similarity between different daily traffic flow time series), which can help us better understand the long-range temporal dependence, such as the origin of crossover phenomenon. Moreover, considering both types of dependence contributes to establishing more accurate model and depicting the properties of traffic flow time series. In this paper, we study the properties of daily temporal dependence by simple average method and Principal Component Analysis (PCA) based method. Meanwhile, we also study the long-range temporal dependence by Detrended Fluctuation Analysis (DFA) and Multifractal Detrended Fluctuation Analysis (MFDFA). The results show that both the daily and long-range temporal dependence exert considerable influence on the traffic flow series. The DFA results reveal that the daily temporal dependence creates crossover phenomenon when estimating the Hurst exponent which depicts the long-range temporal dependence. Furthermore, through the comparison of the DFA test, PCA-based method turns out to be a better method to extract the daily temporal dependence especially when the difference between days is significant.

Efficacy of Re-188-labelled sulphur colloid on prolongation of survival time in melanoma-bearing animals

International Nuclear Information System (INIS)

Chen, F.D.; Hsieh, B.T.; Wang, H.E.; Ou, Y.H.; Yang, W.K.; Whang-Peng, J.; Liu, R.S.; Knapp, F.F.; Ting, G.; Yen, S.H.

2001-01-01

In this study, the effectiveness of a 188 Re labeled sulfur colloid with two particle size ranges was used to evaluate the effectiveness of this agent on melanoma tumors in mice in terms of animal lifespan. Methods: Two separate group of animals were used for investigating biodistribution and survival time. A total of 188 B16F10-melanoma-bearing BDF 1 mice were injected intraperitoneally with 3.7 MBq (0.1mCi)/2mL of radiolabeled sulfur colloid ten days after intraperitoneal inoculation of 5x10 5 B16F10 melanoma cells/2ml. For group 1, 30 mice were sacrificed at 1, 4, 24, 48 and 72 hours for biodistribution studies. In group 2, 158 mice were divided into 9 groups (n=16∼18/groups)each receiving respectively tumor alone, tumor with normal saline, cold colloid or hot colloid with 16, 23, 31, 46, 62, or 124 MBq activity. Each of these colloid groups was further divided into two groups, one receiving smaller particle sizes ( 188 Re-sulfur colloid is an effective agent in controlling tumor cells in the abdominal cavity in animals

Empirical mode decomposition and long-range correlation analysis of sunspot time series

International Nuclear Information System (INIS)

Zhou, Yu; Leung, Yee

2010-01-01

Sunspots, which are the best known and most variable features of the solar surface, affect our planet in many ways. The number of sunspots during a period of time is highly variable and arouses strong research interest. When multifractal detrended fluctuation analysis (MF-DFA) is employed to study the fractal properties and long-range correlation of the sunspot series, some spurious crossover points might appear because of the periodic and quasi-periodic trends in the series. However many cycles of solar activities can be reflected by the sunspot time series. The 11-year cycle is perhaps the most famous cycle of the sunspot activity. These cycles pose problems for the investigation of the scaling behavior of sunspot time series. Using different methods to handle the 11-year cycle generally creates totally different results. Using MF-DFA, Movahed and co-workers employed Fourier truncation to deal with the 11-year cycle and found that the series is long-range anti-correlated with a Hurst exponent, H, of about 0.12. However, Hu and co-workers proposed an adaptive detrending method for the MF-DFA and discovered long-range correlation characterized by H≈0.74. In an attempt to get to the bottom of the problem in the present paper, empirical mode decomposition (EMD), a data-driven adaptive method, is applied to first extract the components with different dominant frequencies. MF-DFA is then employed to study the long-range correlation of the sunspot time series under the influence of these components. On removing the effects of these periods, the natural long-range correlation of the sunspot time series can be revealed. With the removal of the 11-year cycle, a crossover point located at around 60 months is discovered to be a reasonable point separating two different time scale ranges, H≈0.72 and H≈1.49. And on removing all cycles longer than 11 years, we have H≈0.69 and H≈0.28. The three cycle-removing methods—Fourier truncation, adaptive detrending and the

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

Directory of Open Access Journals (Sweden)

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.

Long Range Dependence Prognostics for Bearing Vibration Intensity Chaotic Time Series

Directory of Open Access Journals (Sweden)

Qing Li

2016-01-01

Full Text Available According to the chaotic features and typical fractional order characteristics of the bearing vibration intensity time series, a forecasting approach based on long range dependence (LRD is proposed. In order to reveal the internal chaotic properties, vibration intensity time series are reconstructed based on chaos theory in phase-space, the delay time is computed with C-C method and the optimal embedding dimension and saturated correlation dimension are calculated via the Grassberger–Procaccia (G-P method, respectively, so that the chaotic characteristics of vibration intensity time series can be jointly determined by the largest Lyapunov exponent and phase plane trajectory of vibration intensity time series, meanwhile, the largest Lyapunov exponent is calculated by the Wolf method and phase plane trajectory is illustrated using Duffing-Holmes Oscillator (DHO. The Hurst exponent and long range dependence prediction method are proposed to verify the typical fractional order features and improve the prediction accuracy of bearing vibration intensity time series, respectively. Experience shows that the vibration intensity time series have chaotic properties and the LRD prediction method is better than the other prediction methods (largest Lyapunov, auto regressive moving average (ARMA and BP neural network (BPNN model in prediction accuracy and prediction performance, which provides a new approach for running tendency predictions for rotating machinery and provide some guidance value to the engineering practice.

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

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

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

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.

Mean exit time and survival probability within the CTRW formalism

Science.gov (United States)

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.

The effect of large decoherence on mixing time in continuous-time quantum walks on long-range interacting cycles

Energy Technology Data Exchange (ETDEWEB)

Salimi, S; Radgohar, R, E-mail: shsalimi@uok.ac.i, E-mail: r.radgohar@uok.ac.i [Faculty of Science, Department of Physics, University of Kurdistan, Pasdaran Ave, Sanandaj (Iran, Islamic Republic of)

2010-01-28

In this paper, we consider decoherence in continuous-time quantum walks on long-range interacting cycles (LRICs), which are the extensions of the cycle graphs. For this purpose, we use Gurvitz's model and assume that every node is monitored by the corresponding point-contact induced by the decoherence process. Then, we focus on large rates of decoherence and calculate the probability distribution analytically and obtain the lower and upper bounds of the mixing time. Our results prove that the mixing time is proportional to the rate of decoherence and the inverse of the square of the distance parameter (m). This shows that the mixing time decreases with increasing range of interaction. Also, what we obtain for m = 0 is in agreement with Fedichkin, Solenov and Tamon's results [48] for cycle, and we see that the mixing time of CTQWs on cycle improves with adding interacting edges.

Optical timing receiver for the NASA laser ranging system. Part I. Constant-fraction discriminator

International Nuclear Information System (INIS)

Leskovar, B.; Lo, C.C.

1975-01-01

Position-resolution capabilities of the NASA laser ranging system are essentially determined by time-resolution capabilities of its optical timing receiver. The optical timing receiver consists of a fast photoelectric device, primarily a standard of microchannel-plate-type photomultiplier or an avalanche photodiode detector, a timing discriminator, a high-precision time-interval digitizer, and a signal-processing system. The time-resolution capabilities of the receiver are determined by the photoelectron time spread of the photoelectric device, the time walk and resolution characteristics of the timing discriminator, and the time-interval digitizer. It is thus necessary to evaluate available fast photoelectronic devices with respect to their time-resolution capabilities, and to design a very low time walk timing discriminator and a high-precision time digitizer which will be used in the laser ranging system receiver. (auth)

Application of lidar techniques to time-of-flight range imaging.

Science.gov (United States)

Whyte, Refael; Streeter, Lee; Cree, Michael J; Dorrington, Adrian A

2015-11-20

Amplitude-modulated continuous wave (AMCW) time-of-flight (ToF) range imaging cameras measure distance by illuminating the scene with amplitude-modulated light and measuring the phase difference between the transmitted and reflected modulation envelope. This method of optical range measurement suffers from errors caused by multiple propagation paths, motion, phase wrapping, and nonideal amplitude modulation. In this paper a ToF camera is modified to operate in modes analogous to continuous wave (CW) and stepped frequency continuous wave (SFCW) lidar. In CW operation the velocity of objects can be measured. CW measurement of velocity was linear with true velocity (R2=0.9969). Qualitative analysis of a complex scene confirms that range measured by SFCW is resilient to errors caused by multiple propagation paths, phase wrapping, and nonideal amplitude modulation which plague AMCW operation. In viewing a complicated scene through a translucent sheet, quantitative comparison of AMCW with SFCW demonstrated a reduction in the median error from -1.3  m to -0.06  m with interquartile range of error reduced from 4.0 m to 0.18 m.

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

Directory of Open Access Journals (Sweden)

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…

Canada goose nest survival at rural wetlands in north-central Iowa

Science.gov (United States)

Ness, Brenna N.; Klaver, Robert W.

2016-01-01

The last comprehensive nest survival study of the breeding giant Canada goose (Branta canadensis maxima) population in Iowa, USA, was conducted >30 years ago during a period of population recovery, during which available nesting habitat consisted primarily of artificial nest structures. Currently, Iowa's resident goose population is stable and nests in a variety of habitats. We analyzed the effects of available habitat on nest survival and how nest survival rates compared with those of the expanding goose population studied previously to better understand how to maintain a sustainable Canada goose population in Iowa. We documented Canada goose nest survival at rural wetland sites in north-central Iowa. We monitored 121 nests in 2013 and 149 nests in 2014 at 5 Wildlife Management Areas (WMAs) with various nesting habitats, including islands, muskrat (Ondatra zibethicus) houses, and elevated nest structures. We estimated daily nest-survival rate using the nest survival model in Program MARK. Survival was influenced by year, site, stage, presence of a camera, nest age, and an interaction between nest age and stage. Nest success rates for the 28-day incubation period by site and year combination ranged from 0.10 to 0.84. Nest survival was greatest at sites with nest structures (β = 17.34). Nest survival was negatively affected by lowered water levels at Rice Lake WMA (2013 β = −0.77, nest age β = −0.07). Timing of water-level drawdowns for shallow lake restorations may influence nest survival rates.

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

Science.gov (United States)

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.

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.

Radio frequency (RF) time-of-flight ranging for wireless sensor networks

International Nuclear Information System (INIS)

Thorbjornsen, B; White, N M; Brown, A D; Reeve, J S

2010-01-01

Position information of nodes within wireless sensor networks (WSNs) is often a requirement in order to make use of the data recorded by the sensors themselves. On deployment the nodes normally have no prior knowledge of their position and thus a locationing mechanism is required to determine their positions. In this paper, we describe a method to determine the point-to-point range between sensor nodes as part of the locationing process. A two-way time-of-flight (TOF) ranging scheme is presented using narrow-band RF. The frequency difference between the transceivers involved with the point-to-point measurement is used to obtain a sub-clock TOF phase offset measurement in order to achieve high resolution TOF measurements. The ranging algorithm has been developed and prototyped on a TI CC2430 development kit with no additional hardware being required. Performance results have been obtained for the line-of-sight (LOS), non-line-of-sight (NLOS) and indoor conditions. Accuracy is typically better than 7.0 m RMS for the LOS condition over 250.0 m and 15.8 m RMS for the NLOS condition over 120.0 m using a 100 sample average. Indoor accuracy is measured to 1.7 m RMS using a 1000 sample average over 8.0 m. Ranging error is linear and does not increase with the increased transmitter–receiver distance. Our TOA ranging scheme demonstrates a novel system where resolution and accuracy are time dependent in comparison with alternative frequency-dependent methods using narrow-band RF

Impact of different infliximab dose regimens on treatment response and drug survival in 462 patients with psoriatic arthritis

DEFF Research Database (Denmark)

Glintborg, Bente; Gudbjornsson, Bjorn; Krogh, Niels Steen

2014-01-01

Icelandic patients at baseline [median 3.1 (interquartile range 3.0-3.8) vs 2.3 (2.1-2.9) mg/kg, P drug survival than...... Icelandic patients (1183 vs 483 days). In univariate analyses stratified by country, time until dose escalation, response rates, drug survival and 1-year's disease activity were independent of starting dose. Drug survival was shorter among patients not receiving concomitant MTX. CONCLUSION: In clinical...... practice, > 70% of Icelandic and Danish PsA patients treated with infliximab received sustained doses below the 5 mg/kg every 8 weeks recommended in international guidelines. Lower starting doses did not affect drug survival or response....

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....

Extending the Dynamic Range of a Time Projection Chamber

Science.gov (United States)

Estee, Justin; S πRIT Collaboration

2017-09-01

The use of Time Projection Chambers (TPCs) in intermediate heavy ion reactions faces some challenges in addressing the energy losses that range from the small energy loss of relativistic pions to the large energy loss of slow moving heavy ions. A typical trade-off can be to set the smallest desired signals to be well within the lower limits of the dynamic range of the electronics while allowing for some larger signals to saturate the electronics. With wire plane anodes, signals from readout pads further away from the track remain unsaturated and allow signals from tracks with saturated pads to be accurately recovered. We illustrate this technique using data from the SAMURAI Pion-Reconstruction and Ion-Tracker (S πRIT) TPC , which recently measured pions and light charged particles in collisions of Sn+Sn isotopes. Our method exploits knowledge of how the induced charge distribution depends on the distance from the track to smoothly extend dynamic range even when some of the pads in the track are saturated. To accommodate the analysis of slow moving heavy ions, we have extended the Bichsel energy loss distributions to handle slower moving ions as well. In this talk, I will discuss a combined approach which successfully extends the dynamic range of the TPC electronics. This work is supported by the U.S. DOE under Grant Nos. DE-SC0014530, DE-NA0002923, US NSF Grant No. PHY-1565546 and the Japan MEXT KAKENHI Grant No. 24105004.

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.

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...

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.

Global variations in cancer survival. Study Group on Cancer Survival in Developing Countries.

Science.gov (United States)

Sankaranarayanan, R; Swaminathan, R; Black, R J

1996-12-15

Population-based cancer registries from Algeria, China, Costa Rica, Cuba, India, the Philippines, and Thailand are collaborating with the International Agency for Research on Cancer in a study of cancer survival in developing countries. Comparisons with the SEER program results of the National Cancer Institute in the United States, and the EUROCARE study of survival in European countries revealed considerable differences in the survival of patients with certain tumors associated with intensive chemotherapeutic treatment regimes (Hodgkin's disease and testicular tumors), more modest differences in the survival of patients with tumors for which early diagnosis and treatment confer an improved prognosis (carcinomas of the large bowel, breast, and cervix), and only slight differences for tumors associated with poor prognosis (carcinomas of the stomach, pancreas, and lung). With limited resources to meet the challenge of the increasing incidence of cancer expected in the next few decades, health authorities in developing countries should be aware of the importance of investing in a range of cancer control activities, including primary prevention and early detection programs as well as treatment.

Time delays of supernova neutrinos from new long-range interactions

International Nuclear Information System (INIS)

Malaney, R.A.; Starkman, G.D.; Tremaine, S.

1995-01-01

A new long-range interaction between heavy neutrinos may solve some current problems in large-scale structure, if the new interaction mimics gravity. Assuming that the dark matter is dominated by ∼100 eV τ neutrinos, we investigate whether time delay measurements on supernova neutrinos can test this possibility. We find that such experiments can rule out or detect specific forms of the new interaction potential. In addition, we find the exact dispersive nature of the interacting medium to be critical in determining the time delay: even small corrections to the potential can dramatically alter the magnitude of the effect

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

Science.gov (United States)

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

Survivable integrated grooming in multi-granularity optical networks

Science.gov (United States)

Wu, Jingjing; Guo, Lei; Wei, Xuetao; Liu, Yejun

2012-05-01

Survivability is an important issue to ensure the service continuity in optical network. At the same time, with the granularity of traffic demands ranging from sub-wavelength-level to wavelength-level, traffic demands need to be aggregated and carried over the network in order to utilize resources effectively. Therefore, multi-granularity grooming is proposed to save the cost and reduce the number of switching ports in Optical-Cross Connects (OXCs). However, current works mostly addressed the survivable wavelength or waveband grooming. Therefore, in this paper, we propose three heuristic algorithms called Multi-granularity Dedicated Protection Grooming (MDPG), Multi-granularity Shared Protection Grooming (MSPG) and Multi-granularity Mixed Protection Grooming (MMPG), respectively. All of them are performed based on the Survivable Multi-granularity Integrated Auxiliary Graph (SMIAG) that includes one Wavelength Integrated Auxiliary Graph (WIAG) for wavelength protection and one waveBand Integrated Auxiliary Graph (BIAG) for waveband protection. Numerical results show that MMPG has the lowest average port-cost, the best resource utilization ratio and the lowest blocking probability among these three algorithms. Compared with MDPG, MSPG has lower average port-cost, better resource utilization ratio and lower blocking probability.

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

Directory of Open Access Journals (Sweden)

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.

Segmentation of time series with long-range fractal correlations

Science.gov (United States)

Bernaola-Galván, P.; Oliver, J.L.; Hackenberg, M.; Coronado, A.V.; Ivanov, P.Ch.; Carpena, P.

2012-01-01

Segmentation is a standard method of data analysis to identify change-points dividing a nonstationary time series into homogeneous segments. However, for long-range fractal correlated series, most of the segmentation techniques detect spurious change-points which are simply due to the heterogeneities induced by the correlations and not to real nonstationarities. To avoid this oversegmentation, we present a segmentation algorithm which takes as a reference for homogeneity, instead of a random i.i.d. series, a correlated series modeled by a fractional noise with the same degree of correlations as the series to be segmented. We apply our algorithm to artificial series with long-range correlations and show that it systematically detects only the change-points produced by real nonstationarities and not those created by the correlations of the signal. Further, we apply the method to the sequence of the long arm of human chromosome 21, which is known to have long-range fractal correlations. We obtain only three segments that clearly correspond to the three regions of different G + C composition revealed by means of a multi-scale wavelet plot. Similar results have been obtained when segmenting all human chromosome sequences, showing the existence of previously unknown huge compositional superstructures in the human genome. PMID:23645997

Segmentation of time series with long-range fractal correlations.

Science.gov (United States)

Bernaola-Galván, P; Oliver, J L; Hackenberg, M; Coronado, A V; Ivanov, P Ch; Carpena, P

2012-06-01

Segmentation is a standard method of data analysis to identify change-points dividing a nonstationary time series into homogeneous segments. However, for long-range fractal correlated series, most of the segmentation techniques detect spurious change-points which are simply due to the heterogeneities induced by the correlations and not to real nonstationarities. To avoid this oversegmentation, we present a segmentation algorithm which takes as a reference for homogeneity, instead of a random i.i.d. series, a correlated series modeled by a fractional noise with the same degree of correlations as the series to be segmented. We apply our algorithm to artificial series with long-range correlations and show that it systematically detects only the change-points produced by real nonstationarities and not those created by the correlations of the signal. Further, we apply the method to the sequence of the long arm of human chromosome 21, which is known to have long-range fractal correlations. We obtain only three segments that clearly correspond to the three regions of different G + C composition revealed by means of a multi-scale wavelet plot. Similar results have been obtained when segmenting all human chromosome sequences, showing the existence of previously unknown huge compositional superstructures in the human genome.

Survival, Function, and Complications of Oral Implants Placed in Bone Flaps in Jaw Rehabilitation: A Systematic Review.

Science.gov (United States)

Zhang, Lei; Ding, Qian; Liu, Cunrui; Sun, Yannan; Xie, Qiufei; Zhou, Yongsheng

2016-01-01

This systematic review attempted to determine the survival rate of implants placed in bone flaps in jaw rehabilitation and the functional gains and the most common complications related to these implants. An electronic search was undertaken of PubMed, EMBASE, and CNKI records from 1990 through July 2014. Two independent examiners read the titles and abstracts of the results to identify studies that met the inclusion criteria. Subsequently, the reference lists of the selected publications were hand searched. Descriptive statistics were used to report all data related to the survival rate of implants placed in bone flaps in jaw rehabilitation, the functional gains, and complications. A total of 20 studies were included for systematic review without repetition. The mean follow-up time after implant placement ranged from 1.75 to 9.5 years. Within the limitations of available studies, the survival rate of implants placed in bone flaps in jaw rehabilitation ranged from 82.4% to 100%. Of the 20 included studies, 15 reported a survival rate higher than 90%. The cumulative survival rate was 93.2%, with the longest follow-up time being 12.9 years. The most common complications related to these implants were peri-implant bone resorption or peri-implant inflammation, and peri-implant soft tissue proliferation. The main factors associated with the survival rate of implants in bone flaps were reported as time of implant placement and radiotherapy. Despite some persistent soft tissue problems and implant loss, most patients reached a satisfactory functional and esthetic outcome, as evaluated by clinical examination and subjectively by the patients at interview. Implant-supported dental prosthetic rehabilitation in reconstructed jaws improved the quality of life in terms of speech, nutrition, oral competence, and facial appearance. Placement of implants in bone flaps in jaw rehabilitation was demonstrated to be a reliable technique with a high survival rate. Multicentered

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.

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

Implant survival after total elbow arthroplasty

DEFF Research Database (Denmark)

Plaschke, Hans Christian; Thillemann, Theis M; Brorson, Stig

2014-01-01

in 234 patients at a mean follow-up of 8.7 years (range, 0-27 years). The overall 5-year survival was 90% (95% confidence interval [CI], 88%-94%), and 10-year survival was 81% (95% CI, 76%-86%). TEAs performed with the unlinked design had a relative risk of revision of 1.9 (95% CI, 1.1-3.2) compared...... was to evaluate implant survival and risk factors for revision of TEAs inserted in patients in the eastern part of Denmark in the period from 1980 until 2008. MATERIAL AND METHODS: The Danish National Patient Register provided personal identification numbers for patients who underwent TEA procedures from 1980...

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.

Assessing behavior in Aseel pullets under free-range, part-time free-range, and cage system during growing phase.

Science.gov (United States)

Rehman, M S; Mahmud, A; Mehmood, S; Pasha, T N; Khan, M T; Hussain, J

2018-03-01

The objective of this study was to explore the effects of free-range (FR), part-time free-range (PTFR), and cage system (CS) on behavioral repertoire in Lakha (LK), Mushki (MS), Peshawari (PW), and Sindhi (SN) varieties of Aseel chicken during the growing phase (9 to 18 wk of age). In total, 144 Aseel pullets were allotted to 12 treatment groups in a 3 × 4 (rearing system × Aseel variety) factorial arrangement, according to a randomized complete block design (RCBD). Each treatment group was replicated 3 times with 4 birds in each replicate (12 birds per treatment group). The pullets were randomly marked weekly for identification, and their behavior was observed through the focal animal sampling method. Time spent on different behavioral activities was recorded and converted to a percentage. The data were analyzed using 2-way ANOVA under a factorial arrangement using SAS 9.1, and the behavioral parameters were evaluated. The results indicated greater (P < 0.05) sitting, standing, drinking, preening, and aggressiveness in CS; walking, running, and jumping in PTFR; and foraging and dustbathing in both FR and PTFR, whereas feather pecking was found to be reduced in FR compared with PTFR and CS. Among varieties, PW showed the least feeding/foraging and feather pecking behavior, and greater standing, running, and jumping behavior (P < 0.05). However, SN spent less time in walking and preening, and more time in sitting, drinking, and aggressiveness. Dustbathing was found to be similar in all Aseel varieties (P = 0.135). In conclusion, the PTFR system could be suggested as a substitute for conventional housing systems because it better accommodates normal behavior in Aseel pullets.

Survival after Radiofrequency Ablation in 122 Patients with Inoperable Colorectal Lung Metastases

Energy Technology Data Exchange (ETDEWEB)

Gillams, Alice, E-mail: alliesorting@gmail.com [The London Clinic, Radiology Department (United Kingdom); Khan, Zahid [Countess of Chester Hospital (United Kingdom); Osborn, Peter [Queen Alexandra Hospital (United Kingdom); Lees, William [University College London Medical School (United Kingdom)

2013-06-15

Purpose. To analyze the factors associated with favorable survival in patients with inoperable colorectal lung metastases treated with percutaneous image-guided radiofrequency ablation. Methods. Between 2002 and 2011, a total of 398 metastases were ablated in 122 patients (87 male, median age 68 years, range 29-90 years) at 256 procedures. Percutaneous CT-guided cool-tip radiofrequency ablation was performed under sedation/general anesthesia. Maximum tumor size, number of tumors ablated, number of procedures, concurrent/prior liver ablation, previous liver or lung resection, systemic chemotherapy, disease-free interval from primary resection to lung metastasis, and survival from first ablation were recorded prospectively. Kaplan-Meier analysis was performed, and factors were compared by log rank test. Results. The initial number of metastases ablated was 2.3 (range 1-8); the total number was 3.3 (range 1-15). The maximum tumor diameter was 1.7 (range 0.5-4) cm, and the number of procedures was 2 (range 1-10). The major complication rate was 3.9 %. Overall median and 3-year survival rate were 41 months and 57 %. Survival was better in patients with smaller tumors-a median of 51 months, with 3-year survival of 64 % for tumors 2 cm or smaller versus 31 months and 44 % for tumors 2.1-4 cm (p = 0.08). The number of metastases ablated and whether the tumors were unilateral or bilateral did not affect survival. The presence of treated liver metastases, systemic chemotherapy, or prior lung resection did not affect survival. Conclusion. Three-year survival of 57 % in patients with inoperable colorectal lung metastases is better than would be expected with chemotherapy alone. Patients with inoperable but small-volume colorectal lung metastases should be referred for ablation.

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

Science.gov (United States)

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

A mathematical model resolving normal human blood lymphocyte population X-ray survival curves into six components: radiosensitivity, death rate and size of two responding sub-populations

International Nuclear Information System (INIS)

Thomson, A.E.R.; Vaughan-Smith, S.; Peel, W.E.

1982-01-01

The analysis was based on observations of survival decrease as a function of dose (range 0-5 Gy (= 500 rad)) and time after irradiation in vitro. Since lymphocyte survival is also sensitive to culture conditions the effects of radiation were examined daily up to 3 days only, while survival of control cells remained ca. 90 per cent. The time-dependent changes were resolved as the death rates (first-order governed) of lethally-hit cells (apparent survivors), so rendering these distinguishable from the morphologically identical, true (ultimate) survivors. For 12 blood donors the estimated dose permitting 37 per cent ultimate survival (D 37 value) averaged 0.72 +- 0.18 (SD) Gy for the more radiosensitive lymphocyte fraction and 2.50 +- 0.67 Gy for the less radiosensitive, each fraction proving homogeneously radiosensitive and the latter identifying substantially in kind with T-type (E-rosetting lymphocytes). The half-life of lethally-hit members of either fraction varied widely among the donors (ranges, 25-104 hours and 11-40 hours, respectively). Survival curves reconstructed by summating the numerical estimates of the six parameters according to the theoretical model closely matched those observed experimentally (ranged in multiple correlation coefficient, 0.9709-0.9994) for all donors). This signified the absence of any additional, totally radioresistant cell fraction. (author)

Magnetic resonance spectroscopy metabolite profiles predict survival in paediatric brain tumours.

Science.gov (United States)

Wilson, Martin; Cummins, Carole L; Macpherson, Lesley; Sun, Yu; Natarajan, Kal; Grundy, Richard G; Arvanitis, Theodoros N; Kauppinen, Risto A; Peet, Andrew C

2013-01-01

Brain tumours cause the highest mortality and morbidity rate of all childhood tumour groups and new methods are required to improve clinical management. (1)H magnetic resonance spectroscopy (MRS) allows non-invasive concentration measurements of small molecules present in tumour tissue, providing clinically useful imaging biomarkers. The primary aim of this study was to investigate whether MRS detectable molecules can predict the survival of paediatric brain tumour patients. Short echo time (30ms) single voxel (1)H MRS was performed on children attending Birmingham Children's Hospital with a suspected brain tumour and 115 patients were included in the survival analysis. Patients were followed-up for a median period of 35 months and Cox-Regression was used to establish the prognostic value of individual MRS detectable molecules. A multivariate model of survival was also investigated to improve prognostic power. Lipids and scyllo-inositol predicted poor survival whilst glutamine and N-acetyl aspartate predicted improved survival (pmodel of survival based on three MRS biomarkers predicted survival with a similar accuracy to histologic grading (p5e-5). A negative correlation between lipids and glutamine was found, suggesting a functional link between these molecules. MRS detectable biomolecules have been identified that predict survival of paediatric brain tumour patients across a range of tumour types. The evaluation of these biomarkers in large prospective studies of specific tumour types should be undertaken. The correlation between lipids and glutamine provides new insight into paediatric brain tumour metabolism that may present novel targets for therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

Effects of absolute fasting on reproduction and survival of the invasive apple snail Pomacea canaliculata in its native range.

Science.gov (United States)

Tamburi, Nicolás E; Martín, Pablo R

2016-08-01

A South American freshwater gastropod, the apple snail Pomacea canaliculata, has become a driver of ecosystemic changes in wetlands and an important rice pest after its introduction to various parts of the world, mainly Asia. The objective of this study was to study the effect of an abrupt interruption in food availability in the short term (up to 4 weeks) and long term (up to 8 months) on survival and reproductive activity. The main results indicate that short-term fasting mainly affects the survival of males, but only when they are raised together with females, probably due to a greater mate-searching activity that increases mortality in the individuals with lower reserves. The number of copulating snails or egg-laying females shows an abrupt drop when fasting and a rapid recovery after the food supply is restored. The strategy of discontinuing reproductive activity prioritizes energy conservation for the survival of the females. Interpopulation variation in resistance to starvation was observed in adults, which can be explained to some extent by the food availability that they experienced in their natural environment. No interpopulational differences in survival were seen in hatchlings. The mean maximum values of survival under starvation were 52.6 days in hatchlings and the 3.3% of adults survive over than 200 days, which may be a relevant trait in dispersal and establishment in new habitats.

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

Directory of Open Access Journals (Sweden)

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.

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...

NOAA's Strategy to Improve Operational Weather Prediction Outlooks at Subseasonal Time Range

Science.gov (United States)

Schneider, T.; Toepfer, F.; Stajner, I.; DeWitt, D.

2017-12-01

NOAA is planning to extend operational global numerical weather prediction to sub-seasonal time range under the auspices of its Next Generation Global Prediction System (NGGPS) and Extended Range Outlook Programs. A unification of numerical prediction capabilities for weather and subseasonal to seasonal (S2S) timescales is underway at NOAA using the Finite Volume Cubed Sphere (FV3) dynamical core as the basis for the emerging unified system. This presentation will overview NOAA's strategic planning and current activities to improve prediction at S2S time-scales that are ongoing in response to the Weather Research and Forecasting Innovation Act of 2017, Section 201. Over the short-term, NOAA seeks to improve the operational capability through improvements to its ensemble forecast system to extend its range to 30 days using the new FV3 Global Forecast System model, and by using this system to provide reforecast and re-analyses. In parallel, work is ongoing to improve NOAA's operational product suite for 30 day outlooks for temperature, precipitation and extreme weather phenomena.

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

Directory of Open Access Journals (Sweden)

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.

The influence of scenario-based training and real-time audiovisual feedback on out-of-hospital cardiopulmonary resuscitation quality and survival from out-of-hospital cardiac arrest.

Science.gov (United States)

Bobrow, Bentley J; Vadeboncoeur, Tyler F; Stolz, Uwe; Silver, Annemarie E; Tobin, John M; Crawford, Scott A; Mason, Terence K; Schirmer, Jerome; Smith, Gary A; Spaite, Daniel W

2013-07-01

We assess whether an initiative to optimize out-of-hospital provider cardiopulmonary resuscitation (CPR) quality is associated with improved CPR quality and increased survival from out-of-hospital cardiac arrest. This was a before-after study of consecutive adult out-of-hospital cardiac arrest. Data were obtained from out-of-hospital forms and defibrillators. Phase 1 included 18 months with real-time audiovisual feedback disabled (October 2008 to March 2010). Phase 2 included 16 months (May 2010 to September 2011) after scenario-based training of 373 professional rescuers and real-time audiovisual feedback enabled. The effect of interventions on survival to hospital discharge was assessed with multivariable logistic regression. Multiple imputation of missing data was used to analyze the effect of interventions on CPR quality. Analysis included 484 out-of-hospital cardiac arrest patients (phase 1 232; phase 2 252). Median age was 68 years (interquartile range 56-79); 66.5% were men. CPR quality measures improved significantly from phase 1 to phase 2: Mean chest compression rate decreased from 128 to 106 chest compressions per minute (difference -23 chest compressions; 95% confidence interval [CI] -26 to -19 chest compressions); mean chest compression depth increased from 1.78 to 2.15 inches (difference 0.38 inches; 95% CI 0.28 to 0.47 inches); median chest compression fraction increased from 66.2% to 83.7% (difference 17.6%; 95% CI 15.0% to 20.1%); median preshock pause decreased from 26.9 to 15.5 seconds (difference -11.4 seconds; 95% CI -15.7 to -7.2 seconds), and mean ventilation rate decreased from 11.7 to 9.5/minute (difference -2.2/minute; 95% CI -3.9 to -0.5/minute). All-rhythms survival increased from phase 1 to phase 2 (20/231, 8.7% versus 35/252, 13.9%; difference 5.2%; 95% CI -0.4% to 10.8%), with an adjusted odds ratio of 2.72 (95% CI 1.15 to 6.41), controlling for initial rhythm, witnessed arrest, age, minimally interrupted cardiac resuscitation

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

Science.gov (United States)

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

Percutaneous radiofrequency ablation for early hepatocellular carcinoma: Risk factors for survival

Science.gov (United States)

Kikuchi, Luciana; Menezes, Marcos; Chagas, Aline L; Tani, Claudia M; Alencar, Regiane SSM; Diniz, Marcio A; Alves, Venâncio AF; D’Albuquerque, Luiz Augusto Carneiro; Carrilho, Flair José

2014-01-01

AIM: To evaluate outcomes of radiofrequency ablation (RFA) therapy for early hepatocellular carcinoma (HCC) and identify survival- and recurrence-related factors. METHODS: Consecutive patients diagnosed with early HCC by computed tomography (CT) or magnetic resonance imaging (MRI) (single nodule of ≤ 5 cm, or multi- (up to 3) nodules of ≤ 3 cm each) and who underwent RFA treatment with curative intent between January 2010 and August 2011 at the Instituto do Câncer do Estado de São Paulo, Brazil were enrolled in the study. RFA of the liver tumors (with 1.0 cm ablative margin) was carried out under CT-fluoro scan and ultrasonic image guidance of the percutaneous ablation probes. Procedure-related complications were recorded. At 1-mo post-RFA and 3-mo intervals thereafter, CT and MRI were performed to assess outcomes of complete response (absence of enhancing tissue at the tumor site) or incomplete response (enhancing tissue remaining at the tumor site). Overall survival and disease-free survival rates were estimated by the Kaplan-Meier method and compared by the log rank test or simple Cox regression. The effect of risk factors on survival was assessed by the Cox proportional hazard model. RESULTS: A total of 38 RFA sessions were performed during the study period on 34 patients (age in years: mean, 63 and range, 49-84). The mean follow-up time was 22 mo (range, 1-33). The study population showed predominance of male sex (76%), less severe liver disease (Child-Pugh A, n = 26; Child-Pugh B, n = 8), and single tumor (65%). The maximum tumor diameters ranged from 10 to 50 mm (median, 26 mm). The initial (immediately post-procedure) rate of RFA-induced complete tumor necrosis was 90%. The probability of achieving complete response was significantly greater in patients with a single nodule (vs patients with multi-nodules, P = 0.04). Two patients experienced major complications, including acute pulmonary edema (resolved with intervention) and intestinal perforation

Clinical and molecular markers of long-term survival after oligometastasis-directed stereotactic body radiotherapy (SBRT).

Science.gov (United States)

Wong, Anthony C; Watson, Sydeaka P; Pitroda, Sean P; Son, Christina H; Das, Lauren C; Stack, Melinda E; Uppal, Abhineet; Oshima, Go; Khodarev, Nikolai N; Salama, Joseph K; Weichselbaum, Ralph R; Chmura, Steven J

2016-07-15

The selection of patients for oligometastasis-directed ablative therapy remains a challenge. The authors report on clinical and molecular predictors of survival from a stereotactic body radiotherapy (SBRT) dose-escalation trial for oligometastases. Patients who had from 1 to 5 metastases, a life expectancy of >3 months, and a Karnofsky performance status of >60 received escalating SBRT doses to all known cancer sites. Time to progression, progression-free survival, and overall survival (OS) were calculated at the completion of SBRT, and clinical predictors of OS were modeled. Primary tumor microRNA expression was analyzed to identify molecular predictors of OS. Sixty-one evaluable patients were enrolled from 2004 to 2009. The median follow-up was 2.3 years for all patients (range, 0.2-9.3 years) and 6.8 years for survivors (range, 2.0-9.3 years). The median, 2-year, and 5-year estimated OS were 2.4 years, 57%, and 32%, respectively. The rate of progression after SBRT was associated with an increased risk of death (hazard ratio [HR], 1.44; 95% confidence interval [CI], 1.24-1.82). The time from initial cancer diagnosis to metastasis (HR, 0.98; 95% CI, 0.98-0.99), the time from metastasis to SBRT (HR, 0.98; 95% CI, 0.98-0.99), and breast cancer histology (HR, 0.12; 95% CI, 0.07-0.37) were significant predictors of OS. In an exploratory analysis, a candidate classifier using expression levels of 3 microRNAs (miR-23b, miR-449a, and miR-449b) predicted survival among 17 patients who had primary tumor microRNA expression data available. A subset of oligometastatic patients achieves long-term survival after metastasis-directed SBRT. Clinical features and primary tumor microRNA expression profiling, if validated in an independent dataset, may help select oligometastatic patients most likely to benefit from metastasis-directed therapy. Cancer 2016;122:2242-50. © 2016 American Cancer Society. © 2016 American Cancer Society.

[(90)Yttrium-DOTA]-TOC response is associated with survival benefit in iodine-refractory thyroid cancer: long-term results of a phase 2 clinical trial.

Science.gov (United States)

Iten, Fabienne; Muller, Beat; Schindler, Christian; Rasch, Helmut; Rochlitz, Christoph; Oertli, Daniel; Maecke, Helmut R; Muller-Brand, Jan; Walter, Martin A

2009-05-15

The authors aimed to explore the efficacy of (90)Yttrium-1,4,7,10-tetra-azacyclododecane N,N',N'',N'''-tetraacetic acid [(90)Y-DOTA]-Tyr(3)-octreotide (TOC) in advanced iodine-refractory thyroid cancer. In a phase 2 trial, the authors investigated biochemical response (assessed by serum thyroglobulin levels), survival, and the long-term safety profile of systemic [(90)Y-DOTA]-TOC treatment in metastasized iodine-refractory thyroid cancer. Adverse events were assessed according to the National Cancer Institute criteria. Survival analyses were performed by using multiple regression models. A total of 24 patients were enrolled. A median cumulative activity of 13.0 GBq (range, 1.7-30.3 GBq) was administered. Response was found in 7 (29.2%) patients. Eight (33.3%) patients developed hematologic toxicity grade 1-3, and 4 (16.7%) patients developed renal toxicity grade 1-4. The median survival was 33.4 months (range, 3.6-126.8 months) from time of diagnosis and 16.8 months (range, 1.8-99.1 months) from time of first [(90)Y-DOTA]-TOC treatment. Response to treatment was associated with longer survival from time of diagnosis (hazard ratio [HR], 0.17; 95% confidence interval [CI], 0.03-0.92; P = .04) and from time of first [(90)Y-DOTA]-TOC therapy (HR, 0.20; 95% CI, 0.04-0.94; P = .04). The visual grade of scintigraphic tumor uptake was not associated with treatment response (odds ratio [OR], 0.98; 95% CI, 0.26-3.14; P = 1.00). Response to [(90)Y-DOTA]-TOC in metastasized iodine-refractory thyroid cancer was associated with longer survival. Upcoming trials should aim to increase the number of treatment cycles.

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

Post-relapse survival in patients with Ewing sarcoma.

Science.gov (United States)

Ferrari, Stefano; Luksch, Roberto; Hall, Kirsten Sundby; Fagioli, Franca; Prete, Arcangelo; Tamburini, Angela; Tienghi, Amelia; DiGirolamo, Stefania; Paioli, Anna; Abate, Massimo Eraldo; Podda, Marta; Cammelli, Silvia; Eriksson, Mikael; Brach del Prever, Adalberto

2015-06-01

Post-relapse survival (PRS) was evaluated in patients with Ewing sarcoma (EWS) enrolled in chemotherapy protocols based on the use of high-dose chemotherapy with busulfan and melfalan (HDT) as a first-line consolidation treatment in high-risk patients. EWS patients enrolled in ISG/SSG III and IV trials who relapsed after complete remission were included in the analysis. At recurrence, chemotherapy based on high-dose ifosfamide was foreseen, and patients who responded but had not received HDT underwent consolidation therapy with HDT. Data from 107 EWS patients were included in the analysis. Median time to recurrence (RFI) was 18 months, and 45 (42%) patients had multiple sites of recurrence. Patients who had previously been treated with HDT had a significantly (P = 0.02) shorter RFI and were less likely to achieve a second complete remission (CR2). CR2 status was achieved by 42 (39%) patients. Fifty patients received high-dose IFO (20 went to consolidation HDT). The 5-year PRS was 19% (95% CI 11 to 27%). With CR2, the 5-year PRS was 48% (95% CI 31 to 64%). Without CR2, median time to death was six months (range 1-45 months). According to the multivariate analysis, patients younger than 15 years, recurrence to the lung only, and RFI longer than 24 months significantly influenced the probability of PRS. Age, pattern of recurrence, RFI, and response to second-line chemotherapy influence post-relapse survival in patients with recurrent Ewing sarcoma. No survival advantage was observed from chemotherapy consolidation with HDT. © 2015 Wiley Periodicals, Inc.

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.

Longer dialysis session length is associated with better intermediate outcomes and survival among patients on in-center three times per week hemodialysis: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS).

Science.gov (United States)

Tentori, Francesca; Zhang, Jinyao; Li, Yun; Karaboyas, Angelo; Kerr, Peter; Saran, Rajiv; Bommer, Juergen; Port, Friedrich; Akiba, Takashi; Pisoni, Ronald; Robinson, Bruce

2012-11-01

Longer dialysis session length (treatment time, TT) has been associated with better survival among hemodialysis (HD) patients. The impact of TT on clinical markers that may contribute to this survival advantage is not well known. Using data from the international Dialysis Outcomes and Practice Patterns Study, we assessed the association of TT with clinical outcomes using both standard regression analyses and instrumental variable approaches. The study included 37,414 patients on in-center HD three times per week with prescribed TT from 120 to 420 min. Facility mean TT ranged from 214 min in the USA to 256 min in Australia-New Zealand. Accounting for country effects, mortality risk was lower for patients with longer TT {hazard ratio for every 30 min: all-cause mortality: 0.94 [95% confidence interval (CI): 0.92-0.97], cardiovascular mortality: 0.95 (95% CI: 0.91-0.98) and sudden death: 0.93 (95% CI: 0.88-0.98)}. Patients with longer TT had lower pre- and post-dialysis systolic blood pressure, greater intradialytic weight loss, higher hemoglobin (for the same erythropoietin dose), serum albumin and potassium and lower serum phosphorus and white blood cell counts. Similar associations were found using the instrumental variable approach, although the positive associations of TT with weight loss and potassium were lost. Favorable levels of a variety of clinical markers may contribute to the better survival of patients receiving longer TT. These findings support longer TT prescription in the setting of in-center, three times per week HD.

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

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.

Prolongation of survival of dogs with oral malignant melanoma treated by en bloc surgical resection and adjuvant CSPG4-antigen electrovaccination.

Science.gov (United States)

Piras, L A; Riccardo, F; Iussich, S; Maniscalco, L; Gattino, F; Martano, M; Morello, E; Lorda Mayayo, S; Rolih, V; Garavaglia, F; De Maria, R; Lardone, E; Collivignarelli, F; Mignacca, D; Giacobino, D; Ferrone, S; Cavallo, F; Buracco, P

2017-09-01

Reported post-surgery 1-year survival rate for oral canine malignant melanoma (cMM) is around 30%; novel treatments are needed as the role of adjuvant chemotherapy is unclear. This prospective study regards adjuvant electrovaccination with human chondroitin sulfate proteoglycan-4 (hCSPG4)-encoded plasmid in 23 dogs with resected II/III-staged CSPG4-positive oral cMM compared with 19 dogs with resected only II/III-staged CSPG4-positive oral cMM. Vaccination resulted in 6-, 12-, 18- and 24-month survival rate of 95.6, 73.9, 47.8 and 30.4%, respectively [median survival time (MST) 684 days, range 78-1694, 8 of 23 dogs alive] and 6-, 12-, 18- and 24-month disease-free interval (DFI) rate of 82.6, 47.8, 26.1 and 17.4%, respectively (DFI 477 days, range 50-1694). Non-vaccinated dogs showed 6-, 12-, 18- and 24-month survival rate of 63.2, 26.3, 15.8 and 5.3%, respectively (MST 200 days, range 75-1507, 1 of 19 dogs alive) and 6-, 12-, 18- and 24-month DFI rate of 52.6, 26.3, 10.5 and 5.3%, respectively (DFI 180 days, range 38-1250). Overall survival and DFI of vaccinated dogs was longer in those dogs local recurrence rate was 34.8 and 42%, respectively while lung metastatic rate was 39 and 79%, respectively. © 2016 John Wiley & Sons Ltd.

Lung cancer survival in the United States by race and stage (2001-2009): Findings from the CONCORD-2 study.

Science.gov (United States)

Richards, Thomas B; Henley, S Jane; Puckett, Mary C; Weir, Hannah K; Huang, Bin; Tucker, Thomas C; Allemani, Claudia

2017-12-15

Results from the second CONCORD study (CONCORD-2) indicated that 5-year net survival for lung cancer was low (range, 10%-20%) between 1995 and 2009 in most countries, including the United States, which was at the higher end of this range. Data from CONCORD-2 were used to analyze net survival among patients with lung cancer (aged 15-99 years) who were diagnosed in 37 states covering 80% of the US population. Survival was corrected for background mortality using state-specific and race-specific life tables and age-standardized using International Cancer Survival Standard weights. Net survival was estimated for patients diagnosed between 2001 and 2003 and between 2004 and 2009 at 1, 3, and 5 years after diagnosis by race (all races, black, and white); Surveillance, Epidemiology, and End Results Summary Stage 2000; and US state. Five-year net survival increased from 16.4% (95% confidence interval, 16.3%-16.5%) for patients diagnosed 2001-2003 to 19.0% (18.8%-19.1%) for those diagnosed 2004-2009, with increases in most states and among both blacks and whites. Between 2004 and 2009, 5-year survival was lower among blacks (14.9%) than among whites (19.4%) and ranged by state from 14.5% to 25.2%. Lung cancer survival improved slightly between the periods 2001-2003 and 2004-2009 but was still low, with variation between states, and persistently lower survival among blacks than whites. Efforts to control well established risk factors would be expected to have the greatest impact on reducing the burden of lung cancer, and efforts to ensure that all patients receive timely and appropriate treatment should reduce the differences in survival by race and state. Cancer 2017;123:5079-99. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Climatic variation and age-specific survival in Asian elephants from Myanmar.

Science.gov (United States)

Mumby, Hannah S; Courtiol, Alexandre; Mar, Khyne U; Lummaa, Virpi

2013-05-01

Concern about climate change has intensified interest in understanding how climatic variability affects animal life histories. Despite such effects being potentially most dramatic in large, long-lived, and slowly reproducing terrestrial mammals, little is known of the effects of climatic variation on survival in those species. Asian elephants (Elephas maximus) are endangered across their distribution, and inhabit regions characterized by high seasonality of temperature and rainfall. We investigated the effects of monthly climatic variation on survival and causes of death in Asian elephants using a unique demographic data set of 1024 semi-captive, longitudinally monitored elephants from four sites in Myanmar between 1965 and 2000. Temperature had a significant effect on survival in both sexes and across all ages. For elephants between 1 month and 17 years of age, maximal survival was reached at -24 degrees C, and any departures from this temperature increased mortality, whereas neonates and mature elephants had maximal survival at even lower temperatures. Although males experienced higher mortality overall, sex differences in these optimal temperatures were small. Because the elephants spent more time during a year in temperatures above 24 degrees C than in temperatures below it, most deaths occurred at hot (temperatures>24 degrees C) rather than cold periods. Decreased survival at higher temperatures resulted partially from increased deaths from infectious disease and heat stroke, whereas the lower survival in the coldest months was associated with an increase in noninfectious diseases and poor health in general. Survival was also related to rainfall, with the highest survival rates during the wettest months for all ages and sexes. Our results show that even the normal-range monsoon variation in climate can exert a large impact on elephant survival in Myanmar, leading to extensive absolute differences in mortality; switching from favorable to unfavorable climatic

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

Survival of a cohort of women with cervical cancer diagnosed in a Brazilian cancer center

Directory of Open Access Journals (Sweden)

Claudio Calazan do Carmo

2011-08-01

Full Text Available OBJECTIVE: To assess overall survival of women with cervical cancer and describe prognostic factors associated. METHODS: A total of 3,341 cases of invasive cervical cancer diagnosed at the Brazilian Cancer Institute, Rio de Janeiro, southeastern Brazil, between 1999 and 2004 were selected. Clinical and pathological characteristics and follow-up data were collected. There were performed a survival analysis using Kaplan-Meier curves and a multivariate analysis through Cox model. RESULTS: Of all cases analyzed, 68.3% had locally advanced disease at the time of diagnosis. The 5-year overall survival was 48%. After multivariate analysis, tumor staging at diagnosis was the single variable significantly associated with prognosis (p<0.001. There was seen a dose-response relationship between mortality and clinical staging, ranging from 27.8 to 749.6 per 1,000 cases-year in women stage I and IV, respectively. CONCLUSIONS: The study showed that early detection through prevention programs is crucial to increase cervical cancer survival.

Hypofractionated radiation therapy for invasive thyroid carcinoma in dogs: a retrospective analysis of survival

International Nuclear Information System (INIS)

Brearley, M.J.; Hayes, A.M.; Murphy, S.

1999-01-01

Thirteen dogs with invasive thyroid carcinoma (WHO classification T2b or T3b) seen between January 1991 and October 1997 were treated by external beam Irradiation. Four once-weekly fractions of 9 gray of 4 MeV X-rays were administered. Four of the dogs died of progression of the primary disease and four from metastatic spread. Of the remaining dogs, three died of unrelated problems, although two were still alive at the time of the censor. Kaplan-Meier analysis of the survival time from first dose to death from either primary or metastatic disease gave a median survival time of 96 weeks (mean 85 weeks, range six to 247 weeks). Radiographic evidence of pulmonary metastatic disease at presentation had no prognostic value whereas crude growth rate was a highly significant factor. The present series Indicates that radiation therapy should be considered an important modality for the control of invasive thyroid carcinoma in the dog

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...

Factors affecting 30-month survival in lung cancer patients.

Science.gov (United States)

Mahesh, P A; Archana, S; Jayaraj, B S; Patil, Shekar; Chaya, S K; Shashidhar, H P; Sunitha, B S; Prabhakar, A K

2012-10-01

Age adjusted incidence rate of lung cancer in India ranges from 7.4 to 13.1 per 100,000 among males and 3.9 to 5.8 per 100,000 among females. The factors affecting survival in lung cancer patients in India are not fully understood. The current study was undertaken to evaluate the factors affecting survival in patients diagnosed with lung cancer attending a tertiary care cancer institute in Bangalore, Karnataka, India. Consecutive patients with primary lung cancer attending Bangalore Institute of Oncology, a tertiary care centre at Bangalore, between 2006 and 2009 were included. Demographic, clinical, radiological data were collected retrospectively from the medical records. A total of 170 consecutive subjects (128 males, 42 females) diagnosed to have lung cancer; 151 non-small cell lung cancer (NSCLC) and 19 small cell lung cancer (SCLC) were included. A higher proportion of never-smokers (54.1%) were observed, mostly presenting below the age of 60 yr. Most subjects were in stage IV and III at the time of diagnosis. More than 50 per cent of patients presented with late stage lung cancer even though the duration of symptoms is less than 2 months. The 30-month overall survival rates for smokers and never-smokers were 32 and 49 per cent, respectively. No significant differences were observed in 30 month survival based on age at presentation, gender and type of lung cancer. Cox proportional hazards model identified never-smokers and duration of symptoms less than 1 month as factors adversely affecting survival. Our results showed that lung cancer in Indians involved younger subjects and associated with poorer survival as compared to other ethnic population. Studies on large sample need to be done to evaluate risk factors in lung cancer patients.

Improving Delay-Range-Dependent Stability Condition for Systems with Interval Time-Varying Delay

Directory of Open Access Journals (Sweden)

Wei Qian

2013-01-01

Full Text Available This paper discusses the delay-range-dependent stability for systems with interval time-varying delay. Through defining the new Lyapunov-Krasovskii functional and estimating the derivative of the LKF by introducing new vectors, using free matrices and reciprocally convex approach, the new delay-range-dependent stability conditions are obtained. Two well-known examples are given to illustrate the less conservatism of the proposed theoretical results.

Fluid particles only separate exponentially in the dissipation range of turbulence after extremely long times

Science.gov (United States)

Dhariwal, Rohit; Bragg, Andrew D.

2018-03-01

In this paper, we consider how the statistical moments of the separation between two fluid particles grow with time when their separation lies in the dissipation range of turbulence. In this range, the fluid velocity field varies smoothly and the relative velocity of two fluid particles depends linearly upon their separation. While this may suggest that the rate at which fluid particles separate is exponential in time, this is not guaranteed because the strain rate governing their separation is a strongly fluctuating quantity in turbulence. Indeed, Afik and Steinberg [Nat. Commun. 8, 468 (2017), 10.1038/s41467-017-00389-8] argue that there is no convincing evidence that the moments of the separation between fluid particles grow exponentially with time in the dissipation range of turbulence. Motivated by this, we use direct numerical simulations (DNS) to compute the moments of particle separation over very long periods of time in a statistically stationary, isotropic turbulent flow to see if we ever observe evidence for exponential separation. Our results show that if the initial separation between the particles is infinitesimal, the moments of the particle separation first grow as power laws in time, but we then observe convincing evidence that at sufficiently long times the moments do grow exponentially. However, this exponential growth is only observed after extremely long times ≳200 τη , where τη is the Kolmogorov time scale. This is due to fluctuations in the strain rate about its mean value measured along the particle trajectories, the effect of which on the moments of the particle separation persists for very long times. We also consider the backward-in-time (BIT) moments of the article separation, and observe that they too grow exponentially in the long-time regime. However, a dramatic consequence of the exponential separation is that at long times the difference between the rate of the particle separation forward in time (FIT) and BIT grows

Analysis of short time-space range seismicity patterns in Italy

Directory of Open Access Journals (Sweden)

M. Imotof

1997-06-01

Full Text Available In our paper we analyze the data base obtained from the observations of the Italian Seismological Network from 1975 to 1994 by using a simple algotithm to determine the rate of occurrence of seismic events condi- tioned by the occurrence of previous events after a period of quiescence. The number of observed pairs of earthquakes depends on several parameters: the magnitude threshold of the two events, the spatial and tempo- ral ranges of the quiescence period preceding the first (non aftershock event, the time elapsed between the first and the second events and the spatial dimension of the alarm area. The Akaike information criterion was adopted to assess the optimal set of space-time parameters used in the definition of non-aftershock (events not related to a stronger previous one. In Central Italy, the rate of M ³3.8 earthquakes preceded by at least one M ~ 3.3 foreshock within 14.1 km and 2 days is 30%, while the rate of M ~ 3.3 earthquakes followed by a M ~ 3.8 mainshock in the same space time range is 7%. We observed that the probability that an earthquake of magnitude MI will be followed by an earthquake of magnitude M2 (success rate fits the law log À = a+b (Mi -M2 with b approximately equal to l. By computing the success rate for given values of magnitude threshold of the first and the second events over a dense grid of spatial coordinates, we obtained maps of this feature over the investigated area. The results of this process document variations larger than a factor of five in the success rate over the Italian territory.

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....

Is the effect of non-invasive ventilation on survival in amyotrophic lateral sclerosis age-dependent?

Science.gov (United States)

Siirala, Waltteri; Aantaa, Riku; Olkkola, Klaus T; Saaresranta, Tarja; Vuori, Arno

2013-01-01

Hypoventilation due to respiratory muscle atrophy is the most common cause of death as a result of amyotrophic lateral sclerosis (ALS). Patients aged over 65 years and presenting bulbar symptoms are likely to have a poorer prognosis. The aim of the study was to assess the possible impact of age and treatment with non-invasive ventilation (NIV) on survival in ALS. Based on evidence from earlier studies, it was hypothesized that NIV increases rates of survival regardless of age. Eighty-four patients diagnosed with ALS were followed up on from January 2001 to June 2012. These patients were retrospectively divided into two groups according to their age at the time of diagnosis: Group 1 comprised patients aged ≤ 65 years while Group 2 comprised those aged > 65 years. Each group included 42 patients. NIV was tolerated by 23 patients in Group 1 and 18 patients in Group 2. Survival was measured in months from the date of diagnosis. The median age in Group 1 was 59 years (range 49 - 65) and 76 years in Group 2 (range 66 - 85). Among patients in Group 1 there was no difference in probability of survival between the NIV users and non-users (Hazard Ratio = 0.88, 95% CI 0.44 - 1.77, p = 0.7). NIV users in Group 2 survived longer than those following conventional treatment (Hazard Ratio = 0.25, CI 95% 0.11 - 0.55, p NIV had a 4-fold higher risk for death compared with NIV users. This retrospective study found that NIV use was associated with improved survival outcomes in ALS patients older than 65 years. Further studies in larger patient populations are warranted to determine which factors modify survival outcomes in ALS.

Movement patterns, habitat use, and survival of Lahontan cutthroat trout in the Truckee River

Science.gov (United States)

Alexiades, Alexander V.; Peacock, Mary M.; Al-Chokhachy, Robert K.

2012-01-01

Habitat fragmentation, hybridization, and competition with nonnative salmonids are viewed as major threats to Lahontan cutthroat trout Oncorhynchus clarkii henshawi. Understanding Lahontan cutthroat trout behavior and survival is a necessary step in the reintroduction and establishment of naturally reproducing populations of Lahontan cutthroat trout. We used weekly radiotelemetry monitoring to examine movement patterns, habitat use, and apparent survival of 42 hatchery-reared Lahontan cutthroat trout in a 16.5-km stretch of the Truckee River, Nevada, across three reaches separated by barriers to upstream movement. We found differences in total movement distances and home range sizes of fish in different reaches within our study area. Fish used pool habitats more than fast water habitats in all reaches. Time of year, stream temperature, and fish standard length covariates had the strongest relationship with apparent survival. Monthly apparent survival was lowest in January, which coincided with the lowest flows and temperatures during the study period. Our results verify the mobility of Lahontan cutthroat trout and indicate that conditions during winter may limit the survival and reintroduction success in the portions of the Truckee River evaluated in this 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...

Short-range correlations in an extended time-dependent mean-field theory

International Nuclear Information System (INIS)

Madler, P.

1982-01-01

A generalization is performed of the time-dependent mean-field theory by an explicit inclusion of strong short-range correlations on a level of microscopic reversibility relating them to realistic nucleon-nucleon forces. Invoking a least action principle for correlated trial wave functions, equations of motion for the correlation functions and the single-particle model wave function are derived in lowest order of the FAHT cluster expansion. Higher order effects as well as long-range correlations are consider only to the extent to which they contribute to the mean field via a readjusted phenomenological effective two-body interaction. The corresponding correlated stationary problem is investigated and appropriate initial conditions to describe a heavy ion reaction are proposed. The singleparticle density matrix is evaluated

Social determinants of health and 5-year survival of colorectal cancer.

Science.gov (United States)

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.

Population genomic scans suggest novel genes underlie convergent flowering time evolution in the introduced range of Arabidopsis thaliana.

Science.gov (United States)

Gould, Billie A; Stinchcombe, John R

2017-01-01

A long-standing question in evolutionary biology is whether the evolution of convergent phenotypes results from selection on the same heritable genetic components. Using whole-genome sequencing and genome scans, we tested whether the evolution of parallel longitudinal flowering time clines in the native and introduced ranges of Arabidopsis thaliana has a similar genetic basis. We found that common variants of large effect on flowering time in the native range do not appear to have been under recent strong selection in the introduced range. We identified a set of 38 new candidate genes that are putatively linked to the evolution of flowering time. A high degree of conditional neutrality of flowering time variants between the native and introduced range may preclude parallel evolution at the level of genes. Overall, neither gene pleiotropy nor available standing genetic variation appears to have restricted the evolution of flowering time to high-frequency variants from the native range or to known flowering time pathway genes. © 2016 John Wiley & Sons Ltd.

Real-time image processing of TOF range images using a reconfigurable processor system

Science.gov (United States)

Hussmann, S.; Knoll, F.; Edeler, T.

2011-07-01

During the last years, Time-of-Flight sensors achieved a significant impact onto research fields in machine vision. In comparison to stereo vision system and laser range scanners they combine the advantages of active sensors providing accurate distance measurements and camera-based systems recording a 2D matrix at a high frame rate. Moreover low cost 3D imaging has the potential to open a wide field of additional applications and solutions in markets like consumer electronics, multimedia, digital photography, robotics and medical technologies. This paper focuses on the currently implemented 4-phase-shift algorithm in this type of sensors. The most time critical operation of the phase-shift algorithm is the arctangent function. In this paper a novel hardware implementation of the arctangent function using a reconfigurable processor system is presented and benchmarked against the state-of-the-art CORDIC arctangent algorithm. Experimental results show that the proposed algorithm is well suited for real-time processing of the range images of TOF cameras.

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.

Testing of Rice Stocks for Their Survival of Winter Cold

Directory of Open Access Journals (Sweden)

Hiroshi Ikehashi

2018-03-01

Full Text Available Rice cultivation is considered to be initiated by vegetative propagation of sprout from wild perennial stocks. To test whether any presently cultivated rice cultivar can survive the winter cold or not, rice stocks of several cultivars including indica and japonica types were placed in a shallow pool from October to April in 2015–2016 and 2016–2017. During the coldest period of the winter, the bases of the stocks were placed 5–6 cm below the surface of water, where temperatures ranged from 3 °C to 5 °C, while the surface was frozen for two or three times and covered with snow for a day. Only one cultivar, Nipponbare, a japonica type, survived the winter cold and regenerated sprouts in the end of April or early May. A possibility to develop perennial cultivation of rice or perennial hybrid rice is discussed.

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.

Efficient and Fast Implementation of Embedded Time-of-Flight Ranging System Based on FPGAs

DEFF Research Database (Denmark)

Zhou, Weiguo; Lyu, Congyi; Jiang, Xin

2017-01-01

Time-of-flight cameras perceive depth information about the surrounding environment with an amplitude-modulated near-infrared light source. The distance between the sensor and objects is calculated through measuring the time the light needs to travel. To be used in fast and embedded applications......, such as 3-D reconstruction, visual SLAM, human-robot interactions, and object detection, the 3-D imaging must be performed at high frame rates and accuracy. Thus, this paper presents a real-time field programmable gate arrays platform that calculates the phase shift and then the distance. Experimental...... results shown that the platform can acquire ranging images at the maximum frame rate of 131fps with a fine measurement precision (appropriately 5.1mm range error at 1.2m distance with the proper integration time). Low resource utilization and power consumption of the proposed system make it very suitable...

Population size, survival, growth, and movements of Rana sierrae

Science.gov (United States)

Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Halstead, Brian J.; Link, William

2013-01-01

Based on 2431 captures of 757 individual frogs over a 9-yr period, we found that the population of R. sierrae in one meadow–stream complex in Yosemite National Park ranged from an estimated 45 to 115 adult frogs. Rana sierrae at our relatively low elevation site (2200 m) grew at a fast rate (K = 0.73–0.78), had high overwintering survival rates (44.6–95%), lived a long time (up to 16 yr), and tended to be fairly sedentary during the summer (100% minimum convex polygon annual home ranges of 139 m2) but had low year-to-year site fidelity. Even though the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) has been present in the population for at least 13 yr, there was no clear downward trend as might be expected from reports of R. sierrae population declines associated with Bd or from reports of widespread population decline of R. sierrae throughout its range.

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

Directory of Open Access Journals (Sweden)

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.

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)

Explaining variation in life history timing across a species range: Effects of climate on spawning time in an exploited marine fish

DEFF Research Database (Denmark)

Neuheimer, Anna; MacKenzie, Brian

. Combined, these results shed light on the adaptive capacity of the species in the face of changing climate. We use our results to estimate expected spawning time under future climate regimes, and discuss the implications for codecology and management across the species’ range, and in the greater ecosystem......The capacity of a species to tolerate and/or adapt to environmental conditions will shape its response to future climate change including climate extremes. Of the many life-history processes affected by climate change, timing of reproduction greatly influences offspring success and resulting...... population production. Here we explore temporal and spatial changes in spawning time for Atlantic cod (Gadus morhua) across the species’ range (4 to 80°N). We estimate spawning time using a physiologically relevant metric that includes information on fish thermal history (degree days, DD). First, we estimate...

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 of Lactobacillus rhamnosus strains in the upper gastrointestinal tract.

Science.gov (United States)

Pitino, Iole; Randazzo, Cinzia Lucia; Mandalari, Giuseppina; Lo Curto, Alberto; Faulks, Richard Martin; Le Marc, Yvan; Bisignano, Carlo; Caggia, Cinzia; Wickham, Martin Sean John

2010-12-01

In the present study six probiotic Lactobacillus rhamnosus strains were investigated for their ability to survive in the human upper gastrointestinal tract through a dynamic gastric model of digestion. MRS broth was used as delivery vehicle and survival was investigated during in vitro gastric and gastric plus duodenal digestion. Results highlighted that all tested strains showed good survival rate during both gastric and duodenal digestion. In particular, three strains exhibited a great survival showing a recovery percentage in the range between 117 and 276%. In agreement with survival data, high lactic acid production was detected for all strains, confirming their metabolic activity during digestion. Copyright © 2010 Elsevier Ltd. All rights reserved.

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...

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

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

A new variable interval schedule with constant hazard rate and finite time range.

Science.gov (United States)

Bugallo, Mehdi; Machado, Armando; Vasconcelos, Marco

2018-05-27

We propose a new variable interval (VI) schedule that achieves constant probability of reinforcement in time while using a bounded range of intervals. By sampling each trial duration from a uniform distribution ranging from 0 to 2 T seconds, and then applying a reinforcement rule that depends linearly on trial duration, the schedule alternates reinforced and unreinforced trials, each less than 2 T seconds, while preserving a constant hazard function. © 2018 Society for the Experimental Analysis of Behavior.

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...

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

Science.gov (United States)

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.

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.

The Female Stroke Survival Advantage: Relation to Age

DEFF Research Database (Denmark)

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

2009-01-01

Background: Age-related hormonal factors are thought to be related to the gender gap in longevity. Testing the hypothesis that survival is best in young premenopausal women we studied the effect of age on 1-week mortality in stroke patients. Methods: A registry was started in 2001 with the aim...... in women. While mortality increased almost linearly in women over the entire age range, it increased steeply in men from the age of 50 and at the age of 80 years survival was 80% better in women. Conclusion: The female stroke survival advantage applies to all ages. It increases with age due to a steeply...

Compensation for the distortion in satellite laser range predictions due to varying pulse travel times

Science.gov (United States)

Paunonen, Matti

1993-01-01

A method for compensating for the effect of the varying travel time of a transmitted laser pulse to a satellite is described. The 'observed minus predicted' range differences then appear to be linear, which makes data screening or use in range gating more effective.

Prospective study of serial 18F-FDG PET and 18F-fluoride (18F-NaF) PET to predict time to skeletal related events, time-to-progression, and survival in patients with bone-dominant metastatic breast cancer.

Science.gov (United States)

Peterson, Lanell M; O'Sullivan, Janet; Wu, Qian Vicky; Novakova-Jiresova, Alena; Jenkins, Isaac; Lee, Jean H; Shields, Andrew; Montgomery, Susan; Linden, Hannah M; Gralow, Julie R; Gadi, Vijayakrishna K; Muzi, Mark; Kinahan, Paul E; Mankoff, David A; Specht, Jennifer M

2018-05-10

Assessing therapy response of breast cancer bone metastases is challenging. In retrospective studies, serial 18 F-FDG PET was predictive of time to skeletal related events (tSRE) and time-to-progression (TTP). 18 F-NaF PET improves bone metastasis detection compared to bone scans. We prospectively tested 18 F-FDG PET and 18 F-NaF PET to predict tSRE, TTP, and overall survival (OS) in patients with bone-dominant metastatic breast cancer (BD MBC). Methods: Patients with BD MBC were imaged with 18 F-FDG PET and 18 F-NaF PET prior to starting new therapy (scan1) and again at a range of times centered around approximately 4 months later (scan2). SUV max and SULpeak were recorded for a single index lesion and up to 5 most dominant lesions for each scan. tSRE, TTP, and OS were assessed exclusive of the PET images. Univariate Cox regression was performed to test the association between clinical endpoints and 18 F-FDG PET and 18 F-NaF PET measures. mPERCIST (Modified PET Response Criteria in Solid Tumors) criteria were also applied. Survival curves for mPERCIST compared response categories of Complete Response+Partial Response+Stable Disease versus Progressive Disease (CR+PR+SD vs PD) for tSRE, TTP, and OS. Results: Twenty-eight patients were evaluated. Higher FDG SULpeak at scan2 predicted shorter time to tSRE ( P = PET mPERCIST, tSRE and TTP were longer in responders (CR, PR, or stable) compared to non-responders (PD) ( P = 0.007, 0.028 respectively), with a trend toward improved survival ( P = 0.1). An increase in the uptake between scans of up to 5 lesions by 18 F-NaF PET was associated with longer OS ( P = 0.027). Conclusion: Changes in 18 F-FDG PET parameters during therapy are predictive of tSRE and TTP, but not OS. mPERCIST evaluation in bone lesions may be useful in assessing response to therapy and is worthy of evaluation in multicenter, prospective trials. Serial 18 F-NaF PET was associated with OS, but was not useful for predicting TTP or tSRE in BD MBC

Lamb survival analysis from birth to weaning in Iranian Kermani sheep.

Science.gov (United States)

Barazandeh, Arsalan; Moghbeli, Sadrollah Molaei; Vatankhah, Mahmood; Hossein-Zadeh, Navid Ghavi

2012-04-01

Survival records from 1,763 Kermani lambs born between 1996 and 2004 from 294 ewes and 81 rams were used to determine genetic and non-genetic factors affecting lamb survival. Traits included were lamb survival across five periods from birth to 7, 14, 56, 70, and 90 days of age. Traits were analyzed under Weibull proportional hazard sire models. Several binary analyses were also conducted using animal models. Statistical models included the fixed class effects of sex of lamb, month and year of birth, a covariate effect of birth weight, and random genetic effects of both sire (in survival analyses) and animal (in binary analyses). The average survival to 90 days of age was 94.8%. Hazard rates ranged from 1.00 (birth to 90 days of age) to 1.73 (birth to 7 days of age) between the two sexes indicating that male lambs were at higher risk of mortality than females (P lamb survival and lamb birth weight, suggesting that viability and birth weight could be considered simultaneously in the selection programs to obtain optimal birth weight in Kermani lambs. Estimates of heritabilities from survival analyses were medium and ranged from 0.23 to 0.29. In addition, heritability estimates obtained from binary analyses were low and varied from 0.04 to 0.09. The results of this study suggest that progress in survival traits could be possible through managerial strategies and genetic selection.

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.

Democratic survival in Latin America (1945-2005

Directory of Open Access Journals (Sweden)

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.

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

Compensatory effects of recruitment and survival when amphibian populations are perturbed by disease

Science.gov (United States)

Muths, E.; Scherer, R. D.; Pilliod, D.S.

2011-01-01

The need to increase our understanding of factors that regulate animal population dynamics has been catalysed by recent, observed declines in wildlife populations worldwide. Reliable estimates of demographic parameters are critical for addressing basic and applied ecological questions and understanding the response of parameters to perturbations (e.g. disease, habitat loss, climate change). However, to fully assess the impact of perturbation on population dynamics, all parameters contributing to the response of the target population must be estimated. We applied the reverse-time model of Pradel in Program mark to 6years of capture-recapture data from two populations of Anaxyrus boreas (boreal toad) populations, one with disease and one without. We then assessed a priori hypotheses about differences in survival and recruitment relative to local environmental conditions and the presence of disease. We further explored the relative contribution of survival probability and recruitment rate to population growth and investigated how shifts in these parameters can alter population dynamics when a population is perturbed. High recruitment rates (0??41) are probably compensating for low survival probability (range 0??51-0??54) in the population challenged by an emerging pathogen, resulting in a relatively slow rate of decline. In contrast, the population with no evidence of disease had high survival probability (range 0??75-0??78) but lower recruitment rates (0??25). Synthesis and applications.We suggest that the relationship between survival and recruitment may be compensatory, providing evidence that populations challenged with disease are not necessarily doomed to extinction. A better understanding of these interactions may help to explain, and be used to predict, population regulation and persistence for wildlife threatened with disease. Further, reliable estimates of population parameters such as recruitment and survival can guide the formulation and implementation of

High dynamic range adaptive real-time smart camera: an overview of the HDR-ARTiST project

Science.gov (United States)

Lapray, Pierre-Jean; Heyrman, Barthélémy; Ginhac, Dominique

2015-04-01

Standard cameras capture only a fraction of the information that is visible to the human visual system. This is specifically true for natural scenes including areas of low and high illumination due to transitions between sunlit and shaded areas. When capturing such a scene, many cameras are unable to store the full Dynamic Range (DR) resulting in low quality video where details are concealed in shadows or washed out by sunlight. The imaging technique that can overcome this problem is called HDR (High Dynamic Range) imaging. This paper describes a complete smart camera built around a standard off-the-shelf LDR (Low Dynamic Range) sensor and a Virtex-6 FPGA board. This smart camera called HDR-ARtiSt (High Dynamic Range Adaptive Real-time Smart camera) is able to produce a real-time HDR live video color stream by recording and combining multiple acquisitions of the same scene while varying the exposure time. This technique appears as one of the most appropriate and cheapest solution to enhance the dynamic range of real-life environments. HDR-ARtiSt embeds real-time multiple captures, HDR processing, data display and transfer of a HDR color video for a full sensor resolution (1280 1024 pixels) at 60 frames per second. The main contributions of this work are: (1) Multiple Exposure Control (MEC) dedicated to the smart image capture with alternating three exposure times that are dynamically evaluated from frame to frame, (2) Multi-streaming Memory Management Unit (MMMU) dedicated to the memory read/write operations of the three parallel video streams, corresponding to the different exposure times, (3) HRD creating by combining the video streams using a specific hardware version of the Devebecs technique, and (4) Global Tone Mapping (GTM) of the HDR scene for display on a standard LCD monitor.

Self-produced Time Intervals Are Perceived as More Variable and/or Shorter Depending on Temporal Context in Subsecond and Suprasecond Ranges

Directory of Open Access Journals (Sweden)

Keita eMitani

2016-06-01

Full Text Available The processing of time intervals is fundamental for sensorimotor and cognitive functions. Perceptual and motor timing are often performed concurrently (e.g., playing a musical instrument. Although previous studies have shown the influence of body movements on time perception, how we perceive self-produced time intervals has remained unclear. Furthermore, it has been suggested that the timing mechanisms are distinct for the sub- and suprasecond ranges. Here, we compared perceptual performances for self-produced and passively presented time intervals in random contexts (i.e., multiple target intervals presented in a session across the sub- and suprasecond ranges (Experiment 1 and within the sub- (Experiment 2 and suprasecond (Experiment 3 ranges, and in a constant context (i.e., a single target interval presented in a session in the sub- and suprasecond ranges (Experiment 4. We show that self-produced time intervals were perceived as shorter and more variable across the sub- and suprasecond ranges and within the suprasecond range but not within the subsecond range in a random context. In a constant context, the self-produced time intervals were perceived as more variable in the suprasecond range but not in the subsecond range. The impairing effects indicate that motor timing interferes with perceptual timing. The dependence of impairment on temporal contexts suggests multiple timing mechanisms for the subsecond and suprasecond ranges. In addition, violation of the scalar property (i.e., a constant variability to target interval ratio was observed between the sub- and suprasecond ranges. The violation was clearer for motor timing than for perceptual timing. This suggests that the multiple timing mechanisms for the sub- and suprasecond ranges overlap more for perception than for motor. Moreover, the central tendency effect (i.e., where shorter base intervals are overestimated and longer base intervals are underestimated disappeared with subsecond

Habitat fragmentation reduces nest survival in an Afrotropical bird community in a biodiversity hotspot.

Science.gov (United States)

Newmark, William D; Stanley, Thomas R

2011-07-12

Ecologists have long hypothesized that fragmentation of tropical landscapes reduces avian nest success. However, this hypothesis has not been rigorously assessed because of the difficulty of finding large numbers of well-hidden nests in tropical forests. Here we report that in the East Usambara Mountains in Tanzania, which are part of the Eastern Arc Mountains, a global biodiversity hotspot, that daily nest survival rate and nest success for seven of eight common understory bird species that we examined over a single breeding season were significantly lower in fragmented than in continuous forest, with the odds of nest failure for these seven species ranging from 1.9 to 196.8 times higher in fragmented than continuous forest. Cup-shaped nests were particularly vulnerable in fragments. We then examined over six breeding seasons and 14 study sites in a multivariable survival analysis the influence of landscape structure and nest location on daily nest survival for 13 common species representing 1,272 nests and four nest types (plate, cup, dome, and pouch). Across species and nest types, area, distance of nest to edge, and nest height had a dominant influence on daily nest survival, with area being positively related to nest survival and distance of nest to edge and nest height being both positively and negatively associated with daily nest survival. Our results indicate that multiple environmental factors contribute to reduce nest survival within a tropical understory bird community in a fragmented landscape and that maintaining large continuous forest is important for enhancing nest survival for Afrotropical understory birds.

Plasmodium strain determines dendritic cell function essential for survival from malaria.

Directory of Open Access Journals (Sweden)

Michelle N Wykes

2007-07-01

Full Text Available The severity of malaria can range from asymptomatic to lethal infections involving severe anaemia and cerebral disease. However, the molecular and cellular factors responsible for these differences in disease severity are poorly understood. Identifying the factors that mediate virulence will contribute to developing antiparasitic immune responses. Since immunity is initiated by dendritic cells (DCs, we compared their phenotype and function following infection with either a nonlethal or lethal strain of the rodent parasite, Plasmodium yoelii, to identify their contribution to disease severity. DCs from nonlethal infections were fully functional and capable of secreting cytokines and stimulating T cells. In contrast, DCs from lethal infections were not functional. We then transferred DCs from mice with nonlethal infections to mice given lethal infections and showed that these DCs mediated control of parasitemia and survival. IL-12 was necessary for survival. To our knowledge, our studies have shown for the first time that during a malaria infection, DC function is essential for survival. More importantly, the functions of these DCs are determined by the strain of parasite. Our studies may explain, in part, why natural malaria infections may have different outcomes.

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.

Simultaneous calibration of ensemble river flow predictions over an entire range of lead times

Science.gov (United States)

Hemri, S.; Fundel, F.; Zappa, M.

2013-10-01

Probabilistic estimates of future water levels and river discharge are usually simulated with hydrologic models using ensemble weather forecasts as main inputs. As hydrologic models are imperfect and the meteorological ensembles tend to be biased and underdispersed, the ensemble forecasts for river runoff typically are biased and underdispersed, too. Thus, in order to achieve both reliable and sharp predictions statistical postprocessing is required. In this work Bayesian model averaging (BMA) is applied to statistically postprocess ensemble runoff raw forecasts for a catchment in Switzerland, at lead times ranging from 1 to 240 h. The raw forecasts have been obtained using deterministic and ensemble forcing meteorological models with different forecast lead time ranges. First, BMA is applied based on mixtures of univariate normal distributions, subject to the assumption of independence between distinct lead times. Then, the independence assumption is relaxed in order to estimate multivariate runoff forecasts over the entire range of lead times simultaneously, based on a BMA version that uses multivariate normal distributions. Since river runoff is a highly skewed variable, Box-Cox transformations are applied in order to achieve approximate normality. Both univariate and multivariate BMA approaches are able to generate well calibrated probabilistic forecasts that are considerably sharper than climatological forecasts. Additionally, multivariate BMA provides a promising approach for incorporating temporal dependencies into the postprocessed forecasts. Its major advantage against univariate BMA is an increase in reliability when the forecast system is changing due to model availability.

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

Survival and Neurodevelopmental Outcomes among Periviable Infants.

Science.gov (United States)

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

Photonics-based real-time ultra-high-range-resolution radar with broadband signal generation and processing.

Science.gov (United States)

Zhang, Fangzheng; Guo, Qingshui; Pan, Shilong

2017-10-23

Real-time and high-resolution target detection is highly desirable in modern radar applications. Electronic techniques have encountered grave difficulties in the development of such radars, which strictly rely on a large instantaneous bandwidth. In this article, a photonics-based real-time high-range-resolution radar is proposed with optical generation and processing of broadband linear frequency modulation (LFM) signals. A broadband LFM signal is generated in the transmitter by photonic frequency quadrupling, and the received echo is de-chirped to a low frequency signal by photonic frequency mixing. The system can operate at a high frequency and a large bandwidth while enabling real-time processing by low-speed analog-to-digital conversion and digital signal processing. A conceptual radar is established. Real-time processing of an 8-GHz LFM signal is achieved with a sampling rate of 500 MSa/s. Accurate distance measurement is implemented with a maximum error of 4 mm within a range of ~3.5 meters. Detection of two targets is demonstrated with a range-resolution as high as 1.875 cm. We believe the proposed radar architecture is a reliable solution to overcome the limitations of current radar on operation bandwidth and processing speed, and it is hopefully to be used in future radars for real-time and high-resolution target detection and imaging.

Bi-Directional Brillouin Optical Time Domain Analyzer System for Long Range Distributed Sensing

Science.gov (United States)

Guo, Nan; Wang, Liang; Wang, Jie; Jin, Chao; Tam, Hwa-Yaw; Zhang, A. Ping; Lu, Chao

2016-01-01

We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the conventional unidirectional BOTDA system of the same sensing range, the proposed BD-BOTDA scheme enables distributed sensing with a performance level comparable to the conventional one with half of the sensing range and a spatial resolution of 2 m, while maintaining the Brillouin signal-to-noise ratio (SNR) and the BFS uncertainty. Based on this technique, we have achieved distributed temperature sensing with a measurement range of 81.9 km fiber at a spatial resolution of 2 m and BFS uncertainty of ~0.44 MHz without introducing any complicated components or schemes. PMID:27999250

Bi-Directional Brillouin Optical Time Domain Analyzer System for Long Range Distributed Sensing.

Science.gov (United States)

Guo, Nan; Wang, Liang; Wang, Jie; Jin, Chao; Tam, Hwa-Yaw; Zhang, A Ping; Lu, Chao

2016-12-16

We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the conventional unidirectional BOTDA system of the same sensing range, the proposed BD-BOTDA scheme enables distributed sensing with a performance level comparable to the conventional one with half of the sensing range and a spatial resolution of 2 m, while maintaining the Brillouin signal-to-noise ratio (SNR) and the BFS uncertainty. Based on this technique, we have achieved distributed temperature sensing with a measurement range of 81.9 km fiber at a spatial resolution of 2 m and BFS uncertainty of ~0.44 MHz without introducing any complicated components or schemes.

The Rheology of the Earth in the Intermediate Time Range

Directory of Open Access Journals (Sweden)

A. E. SCHEIDEGGER

1970-06-01

Full Text Available The evidence bearing upon the rheology of the " tectonically
significant layers" of the Earth (" tectonosphere " in the intermediate
time range (4 hours to 15000 years is analyzed. This evidence is
based upon observations of rock-behavior in the laboratory, of seismic
aftershock sequences, of Earth tides and of the decay of the Chandler wobble.
It is shown that of the rheological models (Maxwell-material, Kelvin-material,
and logarithmically creeping material advocated in the literature, only that
based on logarithmic creep does not contradict any of the observational
evidence available to date. In addition, a strength limit may be present.

Investigation of survival time and disability characteristics in 5 subjects with bilateral thalamus infarction near median line%双侧中线旁丘脑梗死5例致残特点及生存期调查

Institute of Scientific and Technical Information of China (English)

翟明; 刘江; 钟静玫; 林岚

2002-01-01

@@ Background:Bilateral thalamus infarction near median line is uncommon in clinic.Reports concerned with this conditions were more less.It is characterized by conscious disorder and Korsakoff syndrome.The main caused may be the injury of intralaminar nuclei,dorsomedial nuclei,and injury of cortical matter,mammalillary bodies,fasciculus thalamicus around cerebral chamer III.Comprehensing the disability characteristics in pateints with bilateral thalamus infarction near median line is important for direction of rehabilitation.While study of survival time will improve evaluation of prognosis. Design:Patients recruited from June 1997～ October 2000 were analyzed. Unit:Intraneural Department of First People's Hospital of Yunnan Province. Subjects:55 subjects with MRI proved bilateral thalamus infarction near median line entered study.These patients included 3 women,2 men(age ranging from 50 to 77 years old,mean age:68.6 years).The period from onset to admission ranged from 5 hours to 2 days.All subejcts experienced acute bilateral thalamus infarction near median line.All had hypertension previously,1 had diabetes,2 had auricular fibrillation. Intervention:All patients received management which was conducted according to protocol for treatment of ischemic cerebrovascular diseases. Patients clinical characteristics were summari-zed and analyzed.Follow up was conducted to determine the survival period. Main evaluation indexes:Survival time and conscious disorder were evaluated. Result:All patients showed different level of conscious disorder.3 cases developed thalamic dementia,2 developed vision numb,In 1 case,condition progressively deteriorated manifesting as moderate coma progressed to deep coma,and bilateral mydriasis.Finally,this patients died of central respiratory and circulatory failure after 8 days.4 cases with favorable prognosis discharged,3 out of them died within 1 year after discharge.Survival subject suffered from reduced memory was followed up till now

Effects of individual quality, reproductive success and environmental variability on survival of a long-lived seabird.

Science.gov (United States)

Lescroël, Amélie; Dugger, Katie M; Ballard, Grant; Ainley, David G

2009-07-01

1. Heterogeneity in individual quality (i.e. individuals having different performance levels that are consistent throughout life) can drive the demography of iteroparous species, but quality in the context of environmental variability has rarely been evaluated. 2. We investigated the demographic responses of a long-lived seabird, the Adélie penguin (Pygoscelis adeliae), to contrasting environmental conditions as a function of reproductive success, breeding quality (BQ) and experience. A continuous index of BQ (BQI) was developed to reflect an individual's ability, relative to others, to produce viable offspring. 3. First, we assessed the relative importance of costs of reproduction vs. heterogeneity in quality by comparing survival and reproductive probabilities among deferred, successful and unsuccessful breeders under 'demanding' conditions using multistate capture-mark-recapture modelling. Then, we quantified the influence of BQI on adult survival among experienced breeders vs. the whole study population under both 'normal' and 'demanding' conditions. 4. Higher survival rates were exhibited by successful (74-76%) compared to unsuccessful breeders (64%); the former also more frequently reproduced successfully at year t + 1. 5. From 1997 to 2006, adult survival ranged from 64-79%, with BQI accounting for 91% of variability in the entire study population, but only 17% in experienced breeders. The weakened relationship between BQI and survival in experienced breeders supports the theory that selection during the first reproductive event accounts for a more homogeneous pool of experienced breeders. 6. No significant effect of environmental covariates on survival was evident, suggesting that what appeared to be demanding conditions were within the range that could be buffered by this species. 7. For the first time in seabirds, a quadratic relationship between adult survival and BQI showed that adult survival is shaped by both heterogeneity in quality and reproductive

Evaluation of the appropriate time range for estimating the apparent permeability coefficient (P(app)) in a transcellular transport study.

Science.gov (United States)

Ozeki, Kazuhisa; Kato, Motohiro; Sakurai, Yuuji; Ishigai, Masaki; Kudo, Toshiyuki; Ito, Kiyomi

2015-11-30

In a transcellular transport study, the apparent permeability coefficient (Papp) of a compound is evaluated using the range by which the amount of compound accumulated on the receiver side is assumed to be proportional to time. However, the time profile of the concentration of the compound in receiver (C3) often shows a lag time before reaching the linear range and later changes from linear to steady state. In this study, the linear range needed to calculate Papp in the C3-time profile was evaluated by a 3-compartment model. C3 was described by an equation with two steady states (C3=A3(1-e(-αt))+B3(1-e(-βt)), α>β), and by a simple approximate line (C3=A3-A3×αt) in the time range of 3/αtime, defined as the interception of the x axis, was described as 1/α. The rate constant α was affected by the membrane permeability clearance and intracellular unbound fraction, while β was affected only by the former. The linear range that was approximated in the present study was not uniformly defined within the time interval in which C3 remains at time range to evaluate Papp was 3/α

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

Earthquake simulations with time-dependent nucleation and long-range interactions

Directory of Open Access Journals (Sweden)

J. H. Dieterich

1995-01-01

Full Text Available A model for rapid simulation of earthquake sequences is introduced which incorporates long-range elastic interactions among fault elements and time-dependent earthquake nucleation inferred from experimentally derived rate- and state-dependent fault constitutive properties. The model consists of a planar two-dimensional fault surface which is periodic in both the x- and y-directions. Elastic interactions among fault elements are represented by an array of elastic dislocations. Approximate solutions for earthquake nucleation and dynamics of earthquake slip are introduced which permit computations to proceed in steps that are determined by the transitions from one sliding state to the next. The transition-driven time stepping and avoidance of systems of simultaneous equations permit rapid simulation of large sequences of earthquake events on computers of modest capacity, while preserving characteristics of the nucleation and rupture propagation processes evident in more detailed models. Earthquakes simulated with this model reproduce many of the observed spatial and temporal characteristics of clustering phenomena including foreshock and aftershock sequences. Clustering arises because the time dependence of the nucleation process is highly sensitive to stress perturbations caused by nearby earthquakes. Rate of earthquake activity following a prior earthquake decays according to Omori's aftershock decay law and falls off with distance.

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

Science.gov (United States)

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

Age-specific survival of tundra swans on the lower Alaska Peninsula

Science.gov (United States)

Meixell, Brandt W.; Lindberg, Mark S.; Conn, Paul B.; Dau, Christian P.; Sarvis, John E.; Sowl, Kristine M.

2013-01-01

The population of Tundra Swans (Cygnus columbianus columbianus) breeding on the lower Alaska Peninsula represents the southern extremity of the species' range and is uniquely nonmigratory. We used data on recaptures, resightings, and recoveries of neck-collared Tundra Swans on the lower Alaska Peninsula to estimate collar loss, annual apparent survival, and other demographic parameters for the years 1978–1989. Annual collar loss was greater for adult males fitted with either the thinner collar type (0.34) or the thicker collar type (0.15) than for other age/sex classes (thinner: 0.10, thicker: 0.04). The apparent mean probability of survival of adults (0.61) was higher than that of immatures (0.41) and for both age classes varied considerably by year (adult range: 0.44–0.95, immature range: 0.25–0.90). To assess effects of permanent emigration by age and breeding class, we analyzed post hoc the encounter histories of swans known to breed in our study area. The apparent mean survival of known breeders (0.65) was generally higher than that of the entire marked sample but still varied considerably by year (range 0.26–1.00) and indicated that permanent emigration of breeding swans was likely. We suggest that reductions in apparent survival probability were influenced primarily by high and variable rates of permanent emigration and that immigration by swans from elsewhere may be important in sustaining a breeding population at and near Izembek National Wildlife Refuge.

Influence of Habitat and Intrinsic Characteristics on Survival of Neonatal Pronghorn.

Directory of Open Access Journals (Sweden)

Christopher N Jacques

Full Text Available Increased understanding of the influence of habitat (e.g., composition, patch size and intrinsic (e.g., age, birth mass factors on survival of neonatal pronghorn (Antilocapra americana is a prerequisite to successful management programs, particularly as they relate to population dynamics and the role of population models in adaptive species management. Nevertheless, few studies have presented empirical data quantifying the influence of habitat variables on survival of neonatal pronghorn. During 2002-2005, we captured and radiocollared 116 neonates across two sites in western South Dakota. We documented 31 deaths during our study, of which coyote (Canis latrans predation (n = 15 was the leading cause of mortality. We used known fate analysis in Program MARK to investigate the influence of intrinsic and habitat variables on neonatal survival. We generated a priori models that we grouped into habitat and intrinsic effects. The highest-ranking model indicated that neonate mortality was best explained by site, percent grassland, and open water habitat; 90-day survival (0.80; 90% CI = 0.71-0.88 declined 23% when grassland and water increased from 80.1 to 92.3% and 0.36 to 0.40%, respectively, across 50% natal home ranges. Further, our results indicated that grassland patch size and shrub density were important predictors of neonate survival; neonate survival declined 17% when shrub density declined from 5.0 to 2.5 patches per 100 ha. Excluding the site covariates, intrinsic factors (i.e., sex, age, birth mass, year, parturition date were not important predictors of survival of neonatal pronghorns. Further, neonatal survival may depend on available land cover and interspersion of habitats. We have demonstrated that maintaining minimum and maximum thresholds for habitat factors (e.g., percentages of grassland and open water patches, density of shrub patches throughout natal home ranges will in turn, ensure relatively high (>0.50 neonatal survival rates

Influence of habitat and intrinsic characteristics on survival of neonatal pronghorn

Science.gov (United States)

Jacques, Christopher N.; Jenks, Jonathan A.; Grovenburg, Troy W.; Klaver, Robert W.

2015-01-01

Increased understanding of the influence of habitat (e.g., composition, patch size) and intrinsic (e.g., age, birth mass) factors on survival of neonatal pronghorn (Antilocapra americana) is a prerequisite to successful management programs, particularly as they relate to population dynamics and the role of population models in adaptive species management. Nevertheless, few studies have presented empirical data quantifying the influence of habitat variables on survival of neonatal pronghorn. During 2002–2005, we captured and radiocollared 116 neonates across two sites in western South Dakota. We documented 31 deaths during our study, of which coyote (Canis latrans) predation (n = 15) was the leading cause of mortality. We used known fate analysis in Program MARK to investigate the influence of intrinsic and habitat variables on neonatal survival. We generated a priori models that we grouped into habitat and intrinsic effects. The highest-ranking model indicated that neonate mortality was best explained by site, percent grassland, and open water habitat; 90-day survival (0.80; 90% CI = 0.71–0.88) declined 23% when grassland and water increased from 80.1 to 92.3% and 0.36 to 0.40%, respectively, across 50% natal home ranges. Further, our results indicated that grassland patch size and shrub density were important predictors of neonate survival; neonate survival declined 17% when shrub density declined from 5.0 to 2.5 patches per 100 ha. Excluding the site covariates, intrinsic factors (i.e., sex, age, birth mass, year, parturition date) were not important predictors of survival of neonatal pronghorns. Further, neonatal survival may depend on available land cover and interspersion of habitats. We have demonstrated that maintaining minimum and maximum thresholds for habitat factors (e.g., percentages of grassland and open water patches, density of shrub patches) throughout natal home ranges will in turn, ensure relatively high (>0.50) neonatal survival rates

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.

Extraneural metastases of medulloblastoma: desmoplastic variants may have prolonged survival.

Science.gov (United States)

Young, Robert J; Khakoo, Yasmin; Yhu, Stephen; Wolden, Suzanne; De Braganca, Kevin C; Gilheeney, Stephen W; Dunkel, Ira J

2015-04-01

Extraneural metastases from CNS medulloblastoma are rare and poorly described. The purpose of this study is to describe the clinical and radiological characteristics of a large single institution series of patients with medulloblastoma who developed extraneural metastases. We retrospectively reviewed a departmental database over a 20 year period for all patients with medulloblastoma who developed extraneural metastases. Chart and imaging reviews were performed, and overall survival (OS) estimated by the Kaplan-Meier method. We found 14 patients with medulloblastoma and extraneural metastases. The median age at initial diagnosis was 16.3 years (range, 3.2-44.2), and the most common subtype was desmoplastic (n = 6, 42.9%). After initial gross total resection, most patients received radiation therapy alone (n = 10, 71.4%). Metastases to bone were most common (n = 11, 78.6%) followed by metastases to bone marrow (n = 6, 42.9%), usually to the spine. The median time from initial diagnosis to first extraneural metastasis was 1.5 years (range, 0.2-17.4), and the median OS from extraneural metastasis to death was 3.3 years (range, 0-18). The Kaplan-Meier estimate of 5 year OS from extraneural metastasis diagnosis was 40.0% (95% CI, 20.2-79.2). Extraneural metastases from medulloblastoma may rarely develop after initial diagnosis to involve bone and bone marrow. We found that desmoplastic variant extraneural tumors had longer survival than nondesmoplastic variants, suggesting that histopathological and more recent molecular subtyping have important roles in determining the prognosis of medulloblastoma patients. © 2014 Wiley Periodicals, Inc.

Dose-time considerations in the treatment of anal cancer

International Nuclear Information System (INIS)

Constantinou, Eugene C.; Daly, William; Fung, Claire Y.; Willett, Christopher G.; De Laney, Thomas F.

1996-01-01

Purpose: Concurrent chemoradiation has become the standard initial treatment of primary anal carcinomas. The objective of this study was to analyze the impact on treatment outcome of a variety of patient and treatment variables including radiation dose and overall treatment time in patients treated with concurrent chemoradiation for anal carcinomas. Materials and Methods: Retrospective chart review on 50 patients with MO anal cancer treated with concurrent chemoradiation during the years 1984-1993. Patients were identified from the hospital tumor registries. The majority of patients received treatment with 5-FU 1000 mg/m 2 days 1-4, 29-33 and Mitomycin 10-15 mg/m 2 days 1 ± 29. Radiation was given at 180-200 cGy daily starting at day 1 to total doses of 23.6-67.2 Gy (median 54 Gy) usually by shrinking field technique. Local control, disease-free survival, and overall survival of the group was determined and then analyzed with respect to a variety of patient characteristics including T and N stage, histology, radiation dose, overall treatment time, hemoglobin at the start of treatment, age, HIV status, and sex. Local control, disease-free and overall survival were calculated using the Kaplan-Meier method. Tests for significance were done using the log-rank method. Results: Patient characteristics were: (1) histology-squamous 78 %, cloacogenic/basaloid 20%, and adenosquamous 2%; (2) age- range 30-82 years (median 58.5), (3) sex- female 58%, male 42%; (4) T stage- T1 16%, T2 46%, T3 24%, T4 8%, TX 6%; (5) N stage- NO 69%, N+ 23 %, NX 8%; (6) HIV (+) 8%, HIV(-/?) 92%. Follow-up ranged from 2-132 months (median 43 months). Overall survival was 66% and 44% at 5 and 10 years. Disease-free survival was 67% at 5 years and 59% at 10 years. Local control was 70% at 5 and 10 years. Five year local control by T stage: T stage- T1 87.5 %, T2 63%, T3 83%, T4 67%, TX 50%. Doses of ≥ 54 Gy are associated with improved 5-year survival (84 % vs. 47%, p=0.02), disease-free survival

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

Precise digital integration in wide time range: theory and realization

International Nuclear Information System (INIS)

Batrakov, A.M.; Pavlenko, A.V.

2017-01-01

The digital integration method based on using high-speed precision analog-to-digital converters (ADC) has become widely used over the recent years. The paper analyzes the limitations of this method that are caused by the signal properties, ADC sampling rate and noise spectral density of the ADC signal path. This analysis allowed creating digital integrators with accurate synchronization and achieving an integration error of less than 10 −5 in the time range from microseconds to tens of seconds. The structure of the integrator is described and its basic parameters are presented. The possibilities of different ADC chips in terms of their applicability to digital integrators are discussed. A comparison with other integrating devices is presented.

Effects of environmental conditions on growth and survival of Salmonella in pasteurized whole egg

DEFF Research Database (Denmark)

Jakociune, Dziuginta; Bisgaard, Magne; Hervé, Gaëlle

2014-01-01

This study investigated the influence of three parameters (time, temperature and NaCl concentration) on survival and four parameters (temperature, NaCl and lysozyme concentrations and pH) on growth of Salmonella enterica serovar Enteritidis (S. Enteritidis) in pasteurized whole egg (PWE). Doehlert......Cl at a fixed heating time of 120s, while maximum growth rate was estimated at 25°C and 0% of NaCl. pH and lysozyme concentration were shown not to influence growth performance significantly in the range of values studied. Results inform industry of the optimal pasteurization and storage parameters for liquid...

Young patients with colorectal cancer have poor survival in the first twenty months after operation and predictable survival in the medium and long-term: Analysis of survival and prognostic markers

Directory of Open Access Journals (Sweden)

Wickramarachchi RE

2010-09-01

Full Text Available Abstract Objectives This study compares clinico-pathological features in young (50 years with colorectal cancer, survival in the young and the influence of pre-operative clinical and histological factors on survival. Materials and methods A twelve year prospective database of colorectal cancer was analysed. Fifty-three young patients were compared with forty seven consecutive older patients over fifty years old. An analysis of survival was undertaken in young patients using Kaplan Meier graphs, non parametric methods, Cox's Proportional Hazard Ratios and Weibull Hazard models. Results Young patients comprised 13.4 percent of 397 with colorectal cancer. Duration of symptoms and presentation in the young was similar to older patients (median, range; young patients; 6 months, 2 weeks to 2 years, older patients; 4 months, 4 weeks to 3 years, p > 0.05. In both groups, the majority presented without bowel obstruction (young - 81%, older - 94%. Cancer proximal to the splenic flexure was present more in young than in older patients. Synchronous cancers were found exclusively in the young. Mucinous tumours were seen in 16% of young and 4% of older patients (p Conclusion If patients, who are less than 40 years old with colorectal cancer, survive twenty months after operation, the prognosis improves and their survival becomes predictable.

Cell survival in a simulated Mars environment

Science.gov (United States)

Todd, Paul; Kurk, Michael Andy; Boland, Eugene; Thomas, David

2016-07-01

The most ancient life forms on earth date back comfortably to the time when liquid water was believed to be abundant on Mars. These ancient life forms include cyanobacteria, contemporary autotrophic earth organisms believed to have descended from ancestors present as long as 3.5 billion years ago. Contemporary cyanobacteria have adapted to the earth environment's harshest conditions (long-term drying, high and low temperature), and, being autotrophic, they are among the most likely life forms to withstand space travel and the Mars environment. However, it is unlikely that humans would unwittingly contaminate a planetary spacecraft with these microbes. One the other hand, heterotrophic microbes that co-habit with humans are more likely spacecraft contaminants, as history attests. Indeed, soil samples from the Atacama desert have yielded colony-forming organisms resembling enteric bacteria. There is a need to understand the survivability of cyanobacteria (likely survivors, unlikely contaminants) and heterotrophic eubacteria (unlikely survivors, likely contaminants) under simulated planetary conditions. A 35-day test was performed in a commercial planetary simulation system (Techshot, Inc., Greenville, IN) in which the minimum night-time temperature was -80 C, the maximum daytime temperature was +26 C, the simulated day-night light cycle in earth hours was 12-on and 12-off, and the total pressure of the pure CO _{2} atmosphere was maintained below 11 mbar. Any water present was allowed to equilibrate with the changing temperature and pressure. The gas phase was sampled into a CR1-A low-pressure hygrometer (Buck Technologies, Boulder, CO), and dew/frost point was measured once every hour and recorded on a data logger, along with the varying temperature in the chamber, from which the partial pressure of water was calculated. According to measurements there was no liquid water present throughout the test except during the initial pump-down period when aqueous specimens

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

Directory of Open Access Journals (Sweden)

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.

Re-evaluating neonatal-age models for ungulates: does model choice affect survival estimates?

Directory of Open Access Journals (Sweden)

Troy W Grovenburg

Full Text Available New-hoof growth is regarded as the most reliable metric for predicting age of newborn ungulates, but variation in estimated age among hoof-growth equations that have been developed may affect estimates of survival in staggered-entry models. We used known-age newborns to evaluate variation in age estimates among existing hoof-growth equations and to determine the consequences of that variation on survival estimates. During 2001-2009, we captured and radiocollared 174 newborn (≤24-hrs old ungulates: 76 white-tailed deer (Odocoileus virginianus in Minnesota and South Dakota, 61 mule deer (O. hemionus in California, and 37 pronghorn (Antilocapra americana in South Dakota. Estimated age of known-age newborns differed among hoof-growth models and varied by >15 days for white-tailed deer, >20 days for mule deer, and >10 days for pronghorn. Accuracy (i.e., the proportion of neonates assigned to the correct age in aging newborns using published equations ranged from 0.0% to 39.4% in white-tailed deer, 0.0% to 3.3% in mule deer, and was 0.0% for pronghorns. Results of survival modeling indicated that variability in estimates of age-at-capture affected short-term estimates of survival (i.e., 30 days for white-tailed deer and mule deer, and survival estimates over a longer time frame (i.e., 120 days for mule deer. Conversely, survival estimates for pronghorn were not affected by estimates of age. Our analyses indicate that modeling survival in daily intervals is too fine a temporal scale when age-at-capture is unknown given the potential inaccuracies among equations used to estimate age of neonates. Instead, weekly survival intervals are more appropriate because most models accurately predicted ages within 1 week of the known age. Variation among results of neonatal-age models on short- and long-term estimates of survival for known-age young emphasizes the importance of selecting an appropriate hoof-growth equation and appropriately defining intervals (i

Connecting single-stock assessment models through correlated survival

DEFF Research Database (Denmark)

Albertsen, Christoffer Moesgaard; Nielsen, Anders; Thygesen, Uffe Høgsbro

2017-01-01

times. We propose a simple alternative. In three case studies each with two stocks, we improve the single-stock models, as measured by Akaike information criterion, by adding correlation in the cohort survival. To limit the number of parameters, the correlations are parameterized through...... the corresponding partial correlations. We consider six models where the partial correlation matrix between stocks follows a band structure ranging from independent assessments to complex correlation structures. Further, a simulation study illustrates the importance of handling correlated data sufficiently...... by investigating the coverage of confidence intervals for estimated fishing mortality. The results presented will allow managers to evaluate stock statuses based on a more accurate evaluation of model output uncertainty. The methods are directly implementable for stocks with an analytical assessment and do...

Coupling between feedback loops in autoregulatory networks affects bistability range, open-loop gain and switching times

International Nuclear Information System (INIS)

Tiwari, Abhinav; Igoshin, Oleg A

2012-01-01

Biochemical regulatory networks governing diverse cellular processes such as stress-response, differentiation and cell cycle often contain coupled feedback loops. We aim at understanding how features of feedback architecture, such as the number of loops, the sign of the loops and the type of their coupling, affect network dynamical performance. Specifically, we investigate how bistability range, maximum open-loop gain and switching times of a network with transcriptional positive feedback are affected by additive or multiplicative coupling with another positive- or negative-feedback loop. We show that a network's bistability range is positively correlated with its maximum open-loop gain and that both quantities depend on the sign of the feedback loops and the type of feedback coupling. Moreover, we find that the addition of positive feedback could decrease the bistability range if we control the basal level in the signal-response curves of the two systems. Furthermore, the addition of negative feedback has the capacity to increase the bistability range if its dissociation constant is much lower than that of the positive feedback. We also find that the addition of a positive feedback to a bistable network increases the robustness of its bistability range, whereas the addition of a negative feedback decreases it. Finally, we show that the switching time for a transition from a high to a low steady state increases with the effective fold change in gene regulation. In summary, we show that the effect of coupled feedback loops on the bistability range and switching times depends on the underlying mechanistic details. (paper)

Concurrent chemoradiotherapy improves survival outcome in muscle-invasive bladder cancer

International Nuclear Information System (INIS)

Byun, Sang Jun; Kim, Jin Hee; Oh, Young Kee; Kim, Byung Hoon

2015-01-01

To evaluate survival rates and prognostic factors related to treatment outcomes after bladder preserving therapy including transurethral resection of bladder tumor, radiotherapy (RT) with or without concurrent chemotherapy in bladder cancer with a curative intent. We retrospectively studied 50 bladder cancer patients treated with bladder-preserving therapy at Keimyung University Dongsan Medical Center from January 1999 to December 2010. Age ranged from 46 to 89 years (median, 71.5 years). Bladder cancer was the American Joint Committee on Cancer (AJCC) stage II, III, and IV in 9, 27, and 14 patients, respectively. Thirty patients were treated with concurrent chemoradiotherapy (CCRT) and 20 patients with RT alone. Nine patients received chemotherapy prior to CCRT or RT alone. Radiation was delivered with a four-field box technique (median, 63 Gy; range, 48.6 to 70.2 Gy). The follow-up periods ranged from 2 to 169 months (median, 34 months). Thirty patients (60%) showed complete response and 13 (26%) a partial response. All patients could have their own bladder preserved. Five-year overall survival (OS) rate was 37.2%, and the 5-year disease-free survival (DFS) rate was 30.2%. In multivariate analysis, tumor grade and CCRT were statistically significant in OS. Tumor grade was a significant prognostic factor related to OS. CCRT is also considered to improve survival outcomes. Further multi-institutional studies are needed to elucidate the impact of RT in bladder cancer

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

Directory of Open Access Journals (Sweden)

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.

Impact of experimental habitat manipulation on northern bobwhite survival

Science.gov (United States)

Peters, David C.; Brooke, Jarred M.; Tanner, Evan P.; Unger, Ashley M.; Keyser, Patrick D.; Harper, Craig A.; Clark, Joseph D.; Morgan, John J.

2015-01-01

Habitat management for northern bobwhite (Colinus virginianus) should affect vital rates, but direct linkages with survival are not well documented; therefore, we implemented an experiment to evaluate those responses. We conducted our experiment on a reclaimed surface mine, a novel landscape where conditions were considered sub-optimal because of the dominance of non-native vegetation, such as sericea lespedeza (Lespedeza cuneata), which has been reported to provide marginal habitat for northern bobwhite and may negatively affect survival. Nonetheless, these areas have great potential for contributing to bobwhite conservation because of the amount of early successional cover they provide. Our study site, a 3,330-ha reclaimed surface mine in western Kentucky, consisted of 2 tracts (Sinclair and Ken, 1,471 ha and 1,853 ha, respectively) that served as replicates with each randomly divided into a treatment (i.e., habitat manipulation through a combination of disking, burning, and herbicide application) and an undisturbed control (n = 4 experimental units). Habitat treatments were applied October 2009 to September 2013. We used radio telemetry to monitor northern bobwhite (n = 1,198) during summer (1 Apr–30 Sep) and winter (1 Oct–31 Mar), 2009–2013. We used the known-fate model in Program MARK to evaluate treatment effects on seasonal survival rates. We included biological, home-range, landscape, and microhabitat metrics as covariates to help improve model sensitivity and further elucidate experimental impacts. Survival varied annually, ranging from 0.139 (SE = 0.031) to 0.301 (SE = 0.032), and seasonally (summer, 0.148 [SE = 0.015]; winter, 0.281 [SE = 0.022]). We found a treatment effect (β = 0.256, 95% CI = 0.057–0.456) with a seasonal interaction (β  = −0.598, 95% CI = −0.898 to −0.298) with survival being higher in summer (0.179 [SE = 0.022] vs. 0.109 [SE = 0.019]) and lower in winter (0.233 [SE�

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)

Net Effects of Ecotourism on Threatened Species Survival.

Directory of Open Access Journals (Sweden)

Ralf C Buckley

Full Text Available Many threatened species rely on ecotourism for conservation funding, but simultaneously suffer direct ecological impacts from ecotourism. For a range of IUCN-Redlisted terrestrial and marine bird and mammal species worldwide, we use population viability analyses to calculate the net effects of ecotourism on expected time to extinction, in the presence of other anthropogenic threats such as poaching, primary industries and habitat loss. Species for which these calculations are currently possible, for one or more subpopulations, include: orangutan, hoolock gibbon, golden lion tamarin, cheetah, African wild dog, New Zealand sealion, great green macaw, Egyptian vulture, and African penguin. For some but not all of these species, tourism can extend expected survival time, i.e., benefits outweigh impacts. Precise outcomes depend strongly on population parameters and starting sizes, predation, and ecotourism scale and mechanisms. Tourism does not currently overcome other major conservation threats associated with natural resource extractive industries. Similar calculations for other threatened species are currently limited by lack of basic population data.

Net Effects of Ecotourism on Threatened Species Survival.

Science.gov (United States)

Buckley, Ralf C; Morrison, Clare; Castley, J Guy

2016-01-01

Many threatened species rely on ecotourism for conservation funding, but simultaneously suffer direct ecological impacts from ecotourism. For a range of IUCN-Redlisted terrestrial and marine bird and mammal species worldwide, we use population viability analyses to calculate the net effects of ecotourism on expected time to extinction, in the presence of other anthropogenic threats such as poaching, primary industries and habitat loss. Species for which these calculations are currently possible, for one or more subpopulations, include: orangutan, hoolock gibbon, golden lion tamarin, cheetah, African wild dog, New Zealand sealion, great green macaw, Egyptian vulture, and African penguin. For some but not all of these species, tourism can extend expected survival time, i.e., benefits outweigh impacts. Precise outcomes depend strongly on population parameters and starting sizes, predation, and ecotourism scale and mechanisms. Tourism does not currently overcome other major conservation threats associated with natural resource extractive industries. Similar calculations for other threatened species are currently limited by lack of basic population data.

Influence of nutrient levels in Tamarix on Diorhabda sublineata (Coleoptera: Chrysomelidae) survival and fitness with implications for biological control.

Science.gov (United States)

Guenther, D A; Gardner, K T; Thompson, D C

2011-02-01

Establishment of the saltcedar leaf beetle (Diorhabda spp.) has been unpredictable when caged or released in the field for saltcedar (Tamarix spp.) biocontrol. It has been observed that one caged tree might be voraciously fed upon by beetles while an adjacent tree in the cage is left untouched. We hypothesized that differences in the nutrient content of individual trees may explain this behavior. We evaluated survival, development rate, and egg production of beetles fed in the laboratory on saltcedar foliage from trees that had been grown under a range of fertilizer treatments. Tissue samples from the experimental trees and from the field were analyzed for percent nitrogen, phosphorus, and potassium. There was essentially no survival of beetle larvae fed foliage from saltcedar trees at nitrogen levels below 2.0%. At levels above 2.0% N, beetle larvae had corresponding increased survival rates and shorter development times. Multiple regression analyses indicated that nitrogen and phosphorus are important for larval survival and faster development rates. Higher levels of potassium were important for increased egg cluster production. The plant tissue analysis showed that the percentage of nitrogen in the experimental trees reflected the range of trees in the field and also that there is high variability within trees in the field. Our research indicates that if beetles are released on trees with poor nutrient quality, the larvae will not survive. © 2011 Entomological Society of America

Survival probabilities of loggerhead sea turtles (Caretta caretta estimated from capture-mark-recapture data in the Mediterranean Sea

Directory of Open Access Journals (Sweden)

Paolo Casale

2007-06-01

Full Text Available Survival probabilities of loggerhead sea turtles (Caretta caretta are estimated for the first time in the Mediterranean by analysing 3254 tagging and 134 re-encounter data from this region. Most of these turtles were juveniles found at sea. Re-encounters were live resightings and dead recoveries and data were analysed with Barker’s model, a modified version of the Cormack-Jolly-Seber model which can combine recapture, live resighting and dead recovery data. An annual survival probability of 0.73 (CI 95% = 0.67-0.78; n=3254 was obtained, and should be considered as a conservative estimate due to an unknown, though not negligible, tag loss rate. This study makes a preliminary estimate of the survival probabilities of in-water developmental stages for the Mediterranean population of endangered loggerhead sea turtles and provides the first insights into the magnitude of the suspected human-induced mortality in the region. The model used here for the first time on sea turtles could be used to obtain survival estimates from other data sets with few or no true recaptures but with other types of re-encounter data, which are a common output of tagging programmes involving these wide-ranging animals.

Influence of socioeconomic status on allograft and patient survival following kidney transplantation.

Science.gov (United States)

Ward, Frank L; O'Kelly, Patrick; Donohue, Fionnuala; ÓhAiseadha, Coilin; Haase, Trutz; Pratschke, Jonathan; deFreitas, Declan G; Johnson, Howard; Conlon, Peter J; O'Seaghdha, Conall M

2015-06-01

Whether socioeconomic status confers worse outcomes after kidney transplantation is unknown. Its influence on allograft and patient survival following kidney transplantation in Ireland was examined. A retrospective, observational cohort study of adult deceased-donor first kidney transplant recipients from 1990 to 2009 was performed. Those with a valid Irish postal address were assigned a socioeconomic status score based on the Pobal Hasse-Pratschke deprivation index and compared in quartiles. Cox proportional hazards models and Kaplan-Meier survival analysis were used to investigate any significant association of socioeconomic status with patient and allograft outcomes. A total of 1944 eligible kidney transplant recipients were identified. The median follow-up time was 8.2 years (interquartile range 4.4-13.3 years). Socioeconomic status was not associated with uncensored or death-censored allograft survival (hazard ratio (HR) 1.0, 95% confidence interval (CI) 0.99-1.00, P = 0.33 and HR 1.0, 95% CI 0.99-1.00, P = 0.37, respectively). Patient survival was not associated with socioeconomic status quartile (HR 1.0, 95% CI 0.93-1.08, P = 0.88). There was no significant difference among quartiles for uncensored or death-censored allograft survival at 5 and 10 years. There was no socioeconomic disparity in allograft or patient outcomes following kidney transplantation, which may be partly attributable to the Irish healthcare model. This may give further impetus to calls in other jurisdictions for universal healthcare and medication coverage for kidney transplant recipients. © 2015 Asian Pacific Society of Nephrology.

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.

Genetic introgression and the survival of Florida panther kittens

Science.gov (United States)

Hostetler, Jeffrey A.; Onorato, David P.; Nichols, James D.; Johnson, Warren E.; Roelke, Melody E.; O'Brien, Stephen J.; Jansen, Deborah; Oli, Madan K.

2010-01-01

Estimates of survival for the young of a species are critical for population models. These models can often be improved by determining the effects of management actions and population abundance on this demographic parameter. We used multiple sources of data collected during 1982–2008 and a live-recapture dead-recovery modeling framework to estimate and model survival of Florida panther (Puma concolor coryi) kittens (age 0–1 year). Overall, annual survival of Florida panther kittens was 0.323 ± 0.071 (SE), which was lower than estimates used in previous population models. In 1995, female pumas from Texas (P. c. stanleyana) were released into occupied panther range as part of an intentional introgression program to restore genetic variability. We found that kitten survival generally increased with degree of admixture: F1 admixed and backcrossed to Texas kittens survived better than canonical Florida panther and backcrossed to canonical kittens. Average heterozygosity positively influenced kitten and older panther survival, whereas index of panther abundance negatively influenced kitten survival. Our results provide strong evidence for the positive population-level impact of genetic introgression on Florida panthers. Our approach to integrate data from multiple sources was effective at improving robustness as well as precision of estimates of Florida panther kitten survival, and can be useful in estimating vital rates for other elusive species with sparse data.

Surgical Resection for Hepatoblastoma-Updated Survival Outcomes.

Science.gov (United States)

Sunil, Bhanu Jayanand; Palaniappan, Ravisankar; Venkitaraman, Balasubramanian; Ranganathan, Rama

2017-09-30

Hepatoblastoma is the most common liver malignancy in the pediatric age group. The management of hepatoblastoma involves multidisciplinary approach. Patients with hepatoblastoma who underwent liver resection between 2000 and 2013 were analyzed and survival outcomes were studied. The crude incidence rate of hepatoblastoma at the Madras Metropolitan Tumor Registry (MMTR) is 0.4/1,00,000 population per year. Twelve patients underwent liver resection for hepatoblastoma during the study period; this included eight males and four females. The median age at presentation was 1.75 years (Range 5 months to 3 years). The median serum AFP in the study population was 20,000 ng/ml (Range 4.5 to 1,40,000 ng/ml). Three patients had stage I, one patient had stage II, and eight patients had stage III disease as per the PRETEXT staging system. Two patients were categorized as high risk and ten patients were categorized as standard risk. Seven of these patients received two to four cycles of neoadjuvant chemotherapy (PLADO regimen), and one patient received neoadjuvant radiation up to 84 Gy. Major liver resection was performed in nine patients. Nine patients received adjuvant chemotherapy. The most common histological subtype was embryonal type. Microscopic margin was positive in three cases. One patient recurred 7 months after surgery and the site of failure was the lung. The 5-year overall survival of the case series was 91%. The median survival was 120 months. Liver resections can be safely performed in pediatric populations after neoadjuvant treatment. Patients undergoing surgery had good disease control and long-term survival.

Real time analysis of electromagnetic radiation in a very wide frequency range

Energy Technology Data Exchange (ETDEWEB)

Peralta, J.A.; Reyes L, P.; Yepez, E. [Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional, Edificio 9, U.P. Adolfo Lopez Mateos, Zacatenco, 07738 Mexico D.F. (Mexico)

2001-07-01

In this work, we present an electronic apparatus that facilitates the monitoring and analysis of electromagnetic radiation in a very wide frequency range. The device is a combination of real and virtual instruments, taking advantage of new hardware and software; the measurable range of frequencies depends on the speed of an analog/digital converter, reaching tens of Megahertz. The device has been successfully used to monitor the environmental electromagnetic radiation at very low frequency, a very useful parameter in the research of electromagnetic precursors of earthquakes. The apparatus is a new configuration and has advantages with respect to those previously used: when the attached computer is fast, Fourier analysis can be done in real time, can display simultaneously several bands, the digitized data allow a variety of methods of analysis, and the apparatus is very cheap. (Author)

Real time analysis of electromagnetic radiation in a very wide frequency range

International Nuclear Information System (INIS)

Peralta, J.A.; Reyes L, P.; Yepez, E.

2001-01-01

In this work, we present an electronic apparatus that facilitates the monitoring and analysis of electromagnetic radiation in a very wide frequency range. The device is a combination of real and virtual instruments, taking advantage of new hardware and software; the measurable range of frequencies depends on the speed of an analog/digital converter, reaching tens of Megahertz. The device has been successfully used to monitor the environmental electromagnetic radiation at very low frequency, a very useful parameter in the research of electromagnetic precursors of earthquakes. The apparatus is a new configuration and has advantages with respect to those previously used: when the attached computer is fast, Fourier analysis can be done in real time, can display simultaneously several bands, the digitized data allow a variety of methods of analysis, and the apparatus is very cheap. (Author)

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.

Time Delay and Long-Range Connection Induced Synchronization Transitions in Newman-Watts Small-World Neuronal Networks

Science.gov (United States)

Qian, Yu

2014-01-01

The synchronization transitions in Newman-Watts small-world neuronal networks (SWNNs) induced by time delay and long-range connection (LRC) probability have been investigated by synchronization parameter and space-time plots. Four distinct parameter regions, that is, asynchronous region, transition region, synchronous region, and oscillatory region have been discovered at certain LRC probability as time delay is increased. Interestingly, desynchronization is observed in oscillatory region. More importantly, we consider the spatiotemporal patterns obtained in delayed Newman-Watts SWNNs are the competition results between long-range drivings (LRDs) and neighboring interactions. In addition, for moderate time delay, the synchronization of neuronal network can be enhanced remarkably by increasing LRC probability. Furthermore, lag synchronization has been found between weak synchronization and complete synchronization as LRC probability is a little less than 1.0. Finally, the two necessary conditions, moderate time delay and large numbers of LRCs, are exposed explicitly for synchronization in delayed Newman-Watts SWNNs. PMID:24810595

Conditional survival in patients with chronic myeloid leukemia in chronic phase in the era of tyrosine kinase inhibitors.

Science.gov (United States)

Sasaki, Koji; Kantarjian, Hagop M; Jain, Preetesh; Jabbour, Elias J; Ravandi, Farhad; Konopleva, Marina; Borthakur, Gautam; Takahashi, Koichi; Pemmaraju, Naveen; Daver, Naval; Pierce, Sherry A; O'Brien, Susan M; Cortes, Jorge E

2016-01-15

Tyrosine kinase inhibitors (TKIs) significantly improve survival in patients with chronic myeloid leukemia in chronic phase (CML-CP). Conditional probability provides survival information in patients who have already survived for a specific period of time after treatment. Cumulative response and survival data from 6 consecutive frontline TKI clinical trials were analyzed. Conditional probability was calculated for failure-free survival (FFS), transformation-free survival (TFS), event-free survival (EFS), and overall survival (OS) according to depth of response within 1 year of the initiation of TKIs, including complete cytogenetic response, major molecular response, and molecular response with a 4-log or 4.5-log reduction. A total of 483 patients with a median follow-up of 99.4 months from the initiation of treatment with TKIs were analyzed. Conditional probabilities of FFS, TFS, EFS, and OS for 1 additional year for patients alive after 12 months of therapy ranged from 92.0% to 99.1%, 98.5% to 100%, 96.2% to 99.6%, and 96.8% to 99.7%, respectively. Conditional FFS for 1 additional year did not improve with a deeper response each year. Conditional probabilities of TFS, EFS, and OS for 1 additional year were maintained at >95% during the period. In the era of TKIs, patients with chronic myeloid leukemia in chronic phase who survived for a certain number of years maintained excellent clinical outcomes in each age group. Cancer 2016;122:238-248. © 2015 American Cancer Society. © 2015 American Cancer Society.

Geographic range did not confer resilience to extinction in terrestrial vertebrates at the end-Triassic crisis.

Science.gov (United States)

Dunhill, Alexander M; Wills, Matthew A

2015-08-11

Rates of extinction vary greatly through geological time, with losses particularly concentrated in mass extinctions. Species duration at other times varies greatly, but the reasons for this are unclear. Geographical range correlates with lineage duration amongst marine invertebrates, but it is less clear how far this generality extends to other groups in other habitats. It is also unclear whether a wide geographical distribution makes groups more likely to survive mass extinctions. Here we test for extinction selectivity amongst terrestrial vertebrates across the end-Triassic event. We demonstrate that terrestrial vertebrate clades with larger geographical ranges were more resilient to extinction than those with smaller ranges throughout the Triassic and Jurassic. However, this relationship weakened with increasing proximity to the end-Triassic mass extinction, breaking down altogether across the event itself. We demonstrate that these findings are not a function of sampling biases; a perennial issue in studies of this kind.

Insulin dependence and pancreatic enzyme replacement therapy are independent prognostic factors for long-term survival after operation for chronic pancreatitis.

Science.gov (United States)

Winny, Markus; Paroglou, Vagia; Bektas, Hüseyin; Kaltenborn, Alexander; Reichert, Benedikt; Zachau, Lea; Kleine, Moritz; Klempnauer, Jürgen; Schrem, Harald

2014-02-01

This retrospective, single-center, observational study on postoperative long-term results aims to define yet unknown factors for long-term outcome after operation for chronic pancreatitis. We analyzed 147 consecutive patients operated for chronic pancreatitis from 2000 to 2011. Mean follow-up was 5.3 years (range, 1 month to 12.7 years). Complete long-term survival data were provided by the German citizen registration authorities for all patients. A quality-of-life questionnaire was sent to surviving patients after a mean follow-up of 5.7 years. Surgical principles were resection (n = 86; 59%), decompression (n = 29; 20%), and hybrid procedures (n = 32; 21%). No significant influences of different surgical principles and operative procedures on survival, long-term quality of life and pain control could be detected. Overall 30-day mortality was 2.7%, 1-year survival 95.9%, and 3-year survival 90.8%. Multivariate Cox regression analysis revealed that only postoperative insulin dependence at the time of hospital discharge (P = .027; Exp(B) = 2.111; 95% confidence interval [CI], 1.089-4.090) and the absence of pancreas enzyme replacement therapy at the time of hospital discharge (P = .039; Exp(B) = 2.102; 95% CI, 1.037-4.262) were significant, independent risk factors for survival with significant hazard ratios for long-term survival. Long-term improvement in quality of life was reported by 55 of 76 long-term survivors (73%). Pancreatic enzyme replacement should be standard treatment after surgery for chronic pancreatitis at the time of hospital discharge, even when no clinical signs of exocrine pancreatic failure exist. This study underlines the potential importance of early operative intervention in chronic pancreatitis before irreversible endocrine dysfunction is present. Copyright © 2014 Mosby, Inc. All rights reserved.

Relationship Between Emergency Medical Services Response Time and Bystander Intervention in Patients With Out-of-Hospital Cardiac Arrest.

Science.gov (United States)

Goto, Yoshikazu; Funada, Akira; Goto, Yumiko

2018-04-27

The response time of emergency medical services (EMS) is an important determinant of survival after out-of-hospital cardiac arrest. We sought to identify upper limits of EMS response times and bystander interventions associated with neurologically intact survival. We analyzed the records of 553 426 patients with out-of-hospital cardiac arrest in a Japanese registry between 2010 and 2014. The primary study end point was 1-month neurologically intact survival (Cerebral Performance Category scale 1 or 2). Increased EMS response time was associated with significantly decreased adjusted odds of 1-month neurologically intact survival (adjusted odds ratio [aOR] for each 1-minute increase, 0.89; 95% confidence interval [CI], 0.89-0.90), although this relationship was modified by bystander interventions. The bystander interventions and the ranges of EMS response times that were associated with increased adjusted 1-month neurologically intact survival were as follows: bystander defibrillation, from ≤2 minutes (aOR, 3.10 [95% CI, 1.25-7.31]) to 13 minutes (aOR, 5.55 [95% CI, 2.66-11.2]); bystander conventional cardiopulmonary resuscitation, from 3 minutes (aOR 1.48 [95% CI, 1.02-2.12]) to 11 minutes (aOR 2.41 [95% CI, 1.61-3.56]); and bystander chest-compression-only cardiopulmonary resuscitation, from ≤2 minutes (aOR 1.57 [95% CI, 1.01-2.25]) to 11 minutes (aOR 1.92 [95% CI, 1.45-2.56]). However, the increase in neurologically intact survival of those receiving bystander interventions became statistically insignificant compared with no bystander interventions when the EMS response time was outside these ranges. The upper limits of the EMS response times associated with improved 1-month neurologically intact survival were 13 minutes when bystanders provided defibrillation (typically with cardiopulmonary resuscitation) and 11 minutes when bystanders provided cardiopulmonary resuscitation without defibrillation. © 2018 The Authors. Published on behalf of the

Postoperative serum CEA level as predictive factor for survival in patients with colorectal cancer

International Nuclear Information System (INIS)

Lemberger, J.J.; Bogar, M.L.; Takacs Kucsera, M.F.; Csernetics, I.F.

2002-01-01

Aim: It is known that routine follow-up of patients with resected colorectal cancer includes serial CEA determinations. In this retrospective study we have investigated relationship between CEA level and survival and whether achieved results enable differentiation of tumors with slow and rapid growth. Material and Methods: Mainly between 1995 and 1999 periodic CEA determination by IRMA were performed in 269 patients after curative resection of colorectal carcinoma. Number of CEA determination/patient were 2-16(median 6). Survival ranged 4,5 and>249,7 months. Based on CEA results patients were divided in group with normal (<10ng/ml) and elevated (=10ng/ml) values regardless of postoperative treatment. Survival curves were computed by Kaplan-Meier method and difference was evaluated by logrank test and difference between proportions. Results:Normal end elevated CEA was found in 193 and 76 patients, respectively. The difference of survival curves between patients with normal and elevated CEA are highly significant (p<0,0001). However, only 10 months after tumor resection is the difference between survived proportions significant suggesting already presence of CEA produced micrometastases contributing to progression of neoplastic process. The mean survival time at normal and elevated CEA values are 142,54±17,86(median 128,60±24,04) and 34,15±4,28 (median 25,20±1,97) months, respectively. No significant difference of survival was found regarding tumor localization. Conclusion:The results show that with regard to CEA level it is possible to divide colorectal tumors on marker negative and positive. Marker negative are with slower growth and relatively good prognosis. Marker positive are associated with elevated CEA level and with considerable shorter survival. Postoperative CEA level is valuable parameter in prediction of patient's outcome

Using demography and movement behavior to predict range expansion of the southern sea otter.

Science.gov (United States)

Tinker, M.T.; Doak, D.F.; Estes, J.A.

2008-01-01

In addition to forecasting population growth, basic demographic data combined with movement data provide a means for predicting rates of range expansion. Quantitative models of range expansion have rarely been applied to large vertebrates, although such tools could be useful for restoration and management of many threatened but recovering populations. Using the southern sea otter (Enhydra lutris nereis) as a case study, we utilized integro-difference equations in combination with a stage-structured projection matrix that incorporated spatial variation in dispersal and demography to make forecasts of population recovery and range recolonization. In addition to these basic predictions, we emphasize how to make these modeling predictions useful in a management context through the inclusion of parameter uncertainty and sensitivity analysis. Our models resulted in hind-cast (1989–2003) predictions of net population growth and range expansion that closely matched observed patterns. We next made projections of future range expansion and population growth, incorporating uncertainty in all model parameters, and explored the sensitivity of model predictions to variation in spatially explicit survival and dispersal rates. The predicted rate of southward range expansion (median = 5.2 km/yr) was sensitive to both dispersal and survival rates; elasticity analysis indicated that changes in adult survival would have the greatest potential effect on the rate of range expansion, while perturbation analysis showed that variation in subadult dispersal contributed most to variance in model predictions. Variation in survival and dispersal of females at the south end of the range contributed most of the variance in predicted southward range expansion. Our approach provides guidance for the acquisition of further data and a means of forecasting the consequence of specific management actions. Similar methods could aid in the management of other recovering populations.

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 of Poliovirus in Flowing Turbid Seawater Treated with Ultraviolet Light

Science.gov (United States)

Hill, W. F.; Hamblet, F. E.; Akin, E. W.

1967-01-01

The effectiveness of a model ultraviolet (UV) radiation unit for treating flowing turbid seawater contaminated with poliovirus was determined. At a turbidity of 70 ppm, the observed survival ratios ranged from 1.9 × 10-3 (99.81% reduction) to 1.5 × 10-4 (99.98% reduction) at flow rates ranging from 25 to 15 liters/min; no virus was recovered at flow rates of 10 and 5 liters/min. At a turbidity of 240 ppm, the observed survival ratios ranged from 3.2 × 10-2 (96.80% reduction) to 2.1 × 10-4 (99.98% reduction) at flow rates ranging from 25 to 5 liters/min. As expected, turbidity had an adverse influence on the effectiveness of UV radiation; however, by adjusting the flow rate of the seawater through the treatment unit, adequate disinfection was shown to be predictable. Images Fig. 1 PMID:4291955

Real-Time Hand Posture Recognition Using a Range Camera

Science.gov (United States)

Lahamy, Herve

The basic goal of human computer interaction is to improve the interaction between users and computers by making computers more usable and receptive to the user's needs. Within this context, the use of hand postures in replacement of traditional devices such as keyboards, mice and joysticks is being explored by many researchers. The goal is to interpret human postures via mathematical algorithms. Hand posture recognition has gained popularity in recent years, and could become the future tool for humans to interact with computers or virtual environments. An exhaustive description of the frequently used methods available in literature for hand posture recognition is provided. It focuses on the different types of sensors and data used, the segmentation and tracking methods, the features used to represent the hand postures as well as the classifiers considered in the recognition process. Those methods are usually presented as highly robust with a recognition rate close to 100%. However, a couple of critical points necessary for a successful real-time hand posture recognition system require major improvement. Those points include the features used to represent the hand segment, the number of postures simultaneously recognizable, the invariance of the features with respect to rotation, translation and scale and also the behavior of the classifiers against non-perfect hand segments for example segments including part of the arm or missing part of the palm. A 3D time-of-flight camera named SR4000 has been chosen to develop a new methodology because of its capability to provide in real-time and at high frame rate 3D information on the scene imaged. This sensor has been described and evaluated for its capability for capturing in real-time a moving hand. A new recognition method that uses the 3D information provided by the range camera to recognize hand postures has been proposed. The different steps of this methodology including the segmentation, the tracking, the hand

Evaluation of Real-Time Hand Motion Tracking Using a Range Camera and the Mean-Shift Algorithm

Science.gov (United States)

Lahamy, H.; Lichti, D.

2011-09-01

Several sensors have been tested for improving the interaction between humans and machines including traditional web cameras, special gloves, haptic devices, cameras providing stereo pairs of images and range cameras. Meanwhile, several methods are described in the literature for tracking hand motion: the Kalman filter, the mean-shift algorithm and the condensation algorithm. In this research, the combination of a range camera and the simple version of the mean-shift algorithm has been evaluated for its capability for hand motion tracking. The evaluation was assessed in terms of position accuracy of the tracking trajectory in x, y and z directions in the camera space and the time difference between image acquisition and image display. Three parameters have been analyzed regarding their influence on the tracking process: the speed of the hand movement, the distance between the camera and the hand and finally the integration time of the camera. Prior to the evaluation, the required warm-up time of the camera has been measured. This study has demonstrated the suitability of the range camera used in combination with the mean-shift algorithm for real-time hand motion tracking but for very high speed hand movement in the traverse plane with respect to the camera, the tracking accuracy is low and requires improvement.

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

Population genetics of the westernmost distribution of the glaciations-surviving black truffle Tuber melanosporum.

Science.gov (United States)

García-Cunchillos, Iván; Sánchez, Sergio; Barriuso, Juan José; Pérez-Collazos, Ernesto

2014-04-01

The black truffle (Tuber melanosporum Vittad.) is an important natural resource due to its relevance as a delicacy in gastronomy. Different aspects of this hypogeous fungus species have been studied, including population genetics of French and Italian distribution ranges. Although those studies include some Spanish populations, this is the first time that the genetic diversity and genetic structure of the wide geographical range of the natural Spanish populations have been analysed. To achieve this goal, 23 natural populations were sampled across the Spanish geographical distribution. ISSR technique demonstrated its reliability and capability to detect high levels of polymorphism in the species. Studied populations showed high levels of genetic diversity (h N  = 0.393, h S  = 0.678, Hs = 0.418), indicating a non threatened genetic conservation status. These high levels may be a consequence of the wide distribution range of the species, of its spore dispersion by animals, and by its evolutionary history. AMOVA analysis showed a high degree of genetic structure among populations (47.89%) and other partitions as geographical ranges. Bayesian genetic structure analyses differentiated two main Spanish groups separated by the Iberian Mountain System, and showed the genetic uniqueness of some populations. Our results suggest the survival of some of these populations during the last glaciation, the Spanish southern distribution range perhaps surviving as had occurred in France and Italy, but it is also likely that specific northern areas may have acted as a refugia for the later dispersion to other calcareous areas in the Iberian Peninsula and probably France.

[Survival pronostic factors in Mexican patients with multiforme glioblastoma].

Science.gov (United States)

Hernández-Reyna, Ricardo; Medellín-Sánchez, Roberto; Cerda-Flores, Ricardo M; Calderón-Garcidueñas, Ana Laura

2010-01-01

To study the pre- and transoperative factors that influence patients' survival with GM. Clinical and pathological records of all confirmed cases of GM diagnosed between 2000 and 2006 were included. Postoperative survival was divided in less or more than 8 months. χ2 test was used. One hundred and twenty patients (45 women and 75 men) were studied. Age range was from 7 to 85 years, 3.3% were 16 years old or younger and 12.5% were 70 years old or older. Headache was the most frequent complain, 40 patients developed hemiparesia and 6 had parestesias. Predominance of white matter hemispheric lesions was observed: right hemispheric tumors 65 (54%), left lesions 30 (25%) and bilateral tumors 7%. Histologically, 1.6% of GM had a sarcomatous component; 35% of patients survived less than 8 months. A difference between patients survival was the preoperative Karnofsky Performance Scale Score and the degree of cerebral edema during the surgical procedure. Pre-operative Karnofsky evaluation and edema during the surgical procedure were significant prognostic factors for survival.

Survival of human diploid skin fibroblasts from normal individuals after X-irradiation

International Nuclear Information System (INIS)

Little, J.B.; Nove, J.; Strong, L.C.; Nichols, W.W.

1988-01-01

The cytotoxic effect of X-rays was measured by a colony formation assay in multiple experiments with fibroblast cell strains derived from 24 presumably normal individuals, received as 65 different coded and blinded samples. Each strain was received on two or more occasions at different times and bearing different codes. The means and standard deviations of the survival curve parameters for the 24 strains were: D 0 = 123 +- 23; D 10 = 273 +- 42 cGy. The D 0 ranged from 89 to 175 and the D 10 from 196 to 372 cGy. The degree of interexperimental variation, though generally minimal, differed considerably among cell strains. There was no systematic effect of passage level, cloning efficiency, serum lot, age or sex of the donor on X-ray survival. These results confirm that the intrinsic radiosensitivity varies significantly among skin fibroblasts isolated from clinically normal individuals, apparently owing to as yet unidentified genetic factors. (Author)

Angle-dependent strong-field molecular ionization rates with tuned range-separated time-dependent density functional theory

Energy Technology Data Exchange (ETDEWEB)

Sissay, Adonay [Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Abanador, Paul; Mauger, François; Gaarde, Mette; Schafer, Kenneth J. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Lopata, Kenneth, E-mail: klopata@lsu.edu [Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)

2016-09-07

Strong-field ionization and the resulting electronic dynamics are important for a range of processes such as high harmonic generation, photodamage, charge resonance enhanced ionization, and ionization-triggered charge migration. Modeling ionization dynamics in molecular systems from first-principles can be challenging due to the large spatial extent of the wavefunction which stresses the accuracy of basis sets, and the intense fields which require non-perturbative time-dependent electronic structure methods. In this paper, we develop a time-dependent density functional theory approach which uses a Gaussian-type orbital (GTO) basis set to capture strong-field ionization rates and dynamics in atoms and small molecules. This involves propagating the electronic density matrix in time with a time-dependent laser potential and a spatial non-Hermitian complex absorbing potential which is projected onto an atom-centered basis set to remove ionized charge from the simulation. For the density functional theory (DFT) functional we use a tuned range-separated functional LC-PBE*, which has the correct asymptotic 1/r form of the potential and a reduced delocalization error compared to traditional DFT functionals. Ionization rates are computed for hydrogen, molecular nitrogen, and iodoacetylene under various field frequencies, intensities, and polarizations (angle-dependent ionization), and the results are shown to quantitatively agree with time-dependent Schrödinger equation and strong-field approximation calculations. This tuned DFT with GTO method opens the door to predictive all-electron time-dependent density functional theory simulations of ionization and ionization-triggered dynamics in molecular systems using tuned range-separated hybrid functionals.

Angle-dependent strong-field molecular ionization rates with tuned range-separated time-dependent density functional theory

International Nuclear Information System (INIS)

Sissay, Adonay; Abanador, Paul; Mauger, François; Gaarde, Mette; Schafer, Kenneth J.; Lopata, Kenneth

2016-01-01

Strong-field ionization and the resulting electronic dynamics are important for a range of processes such as high harmonic generation, photodamage, charge resonance enhanced ionization, and ionization-triggered charge migration. Modeling ionization dynamics in molecular systems from first-principles can be challenging due to the large spatial extent of the wavefunction which stresses the accuracy of basis sets, and the intense fields which require non-perturbative time-dependent electronic structure methods. In this paper, we develop a time-dependent density functional theory approach which uses a Gaussian-type orbital (GTO) basis set to capture strong-field ionization rates and dynamics in atoms and small molecules. This involves propagating the electronic density matrix in time with a time-dependent laser potential and a spatial non-Hermitian complex absorbing potential which is projected onto an atom-centered basis set to remove ionized charge from the simulation. For the density functional theory (DFT) functional we use a tuned range-separated functional LC-PBE*, which has the correct asymptotic 1/r form of the potential and a reduced delocalization error compared to traditional DFT functionals. Ionization rates are computed for hydrogen, molecular nitrogen, and iodoacetylene under various field frequencies, intensities, and polarizations (angle-dependent ionization), and the results are shown to quantitatively agree with time-dependent Schrödinger equation and strong-field approximation calculations. This tuned DFT with GTO method opens the door to predictive all-electron time-dependent density functional theory simulations of ionization and ionization-triggered dynamics in molecular systems using tuned range-separated hybrid functionals.

Survival of Vibrio cholerae O1 on fomites

DEFF Research Database (Denmark)

Farhana, Israt; Hossain, Zenat Zebin; Tulsiani, Suhella Mohan

2016-01-01

conditions on fomites, bacteria have been known to assume a viable but non-culturable (VBNC) state after a given period of time. To investigate whether and when V. cholerae O1 assumes such a state, this study investigated the survival and viable quantification on a range of fomites such as paper, wood, glass......, plastic, cloth and several types of metals under laboratory conditions. The fomites were inoculated with an outbreak strain of V. cholerae and its culturability was examined by drop plate count method at 30 min intervals for up to 6 h. For molecular detection, the viable/dead stain ethidium monoazide (EMA......) which inhibits amplification of DNA from dead cells was used in combination with real-time polymerase chain reaction (EMA-qPCR) for direct quantitative analyses of viable V. cholerae at 2, 4, 6, 24 h and 7 day time intervals. Results showed that V. cholerae on glass and aluminum surfaces lost...

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

Science.gov (United States)

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

Adverse effect of excess body weight on survival in cervical cancer patients after surgery and radiotherapy

International Nuclear Information System (INIS)

Choi, Yunseon; Ahn, Ki Jung; Park, Sung Kwang; Cho, Heung Lae; Lee, Ji Young

2017-01-01

This study aimed to assess the effects of body mass index (BMI) on survival in cervical cancer patients who had undergone surgery and radiotherapy (RT). We retrospectively reviewed the medical records of 70 cervical cancer patients who underwent surgery and RT from 2007 to 2012. Among them, 40 patients (57.1%) had pelvic lymph node metastases at the time of diagnosis. Sixty-seven patients (95.7%) had received chemotherapy. All patients had undergone surgery and postoperative RT. Median BMI of patients was 22.8 kg/m2 (range, 17.7 to 35.9 kg/m2). The median duration of follow-up was 52.3 months (range, 16 to 107 months). Twenty-four patients (34.3%) showed recurrence. Local failure, regional lymph nodal failure, and distant failure occurred in 4 (5.7%), 6 (8.6%), and 17 (24.3%) patients, respectively. The 5-year actuarial pelvic control rate was 83.4%. The 5-year cancer-specific survival (CSS) and disease-free survival (DFS) rates were 85.1% and 65.0%, respectively. The presence of pelvic lymph node metastases (n = 30) and being overweight or obese (n = 34, BMI ≥ 23 kg/m2) were poor prognostic factors for CSS (p = 0.003 and p = 0.045, respectively). Of these, pelvic lymph node metastasis was an independent prognostic factor (p = 0.030) for CSS. Overweight or obese cervical cancer patients showed poorer survival outcomes than normal weight or underweight patients. Weight control seems to be important in cervical cancer patients to improve clinical outcomes

Adverse effect of excess body weight on survival in cervical cancer patients after surgery and radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Choi, Yunseon; Ahn, Ki Jung; Park, Sung Kwang; Cho, Heung Lae; Lee, Ji Young [Inje University Busan Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

2017-03-15

This study aimed to assess the effects of body mass index (BMI) on survival in cervical cancer patients who had undergone surgery and radiotherapy (RT). We retrospectively reviewed the medical records of 70 cervical cancer patients who underwent surgery and RT from 2007 to 2012. Among them, 40 patients (57.1%) had pelvic lymph node metastases at the time of diagnosis. Sixty-seven patients (95.7%) had received chemotherapy. All patients had undergone surgery and postoperative RT. Median BMI of patients was 22.8 kg/m2 (range, 17.7 to 35.9 kg/m2). The median duration of follow-up was 52.3 months (range, 16 to 107 months). Twenty-four patients (34.3%) showed recurrence. Local failure, regional lymph nodal failure, and distant failure occurred in 4 (5.7%), 6 (8.6%), and 17 (24.3%) patients, respectively. The 5-year actuarial pelvic control rate was 83.4%. The 5-year cancer-specific survival (CSS) and disease-free survival (DFS) rates were 85.1% and 65.0%, respectively. The presence of pelvic lymph node metastases (n = 30) and being overweight or obese (n = 34, BMI ≥ 23 kg/m2) were poor prognostic factors for CSS (p = 0.003 and p = 0.045, respectively). Of these, pelvic lymph node metastasis was an independent prognostic factor (p = 0.030) for CSS. Overweight or obese cervical cancer patients showed poorer survival outcomes than normal weight or underweight patients. Weight control seems to be important in cervical cancer patients to improve clinical outcomes.

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...

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.

Clinical outcomes and survival in AA amyloidosis patients

Directory of Open Access Journals (Sweden)

Yavuz Ayar

Full Text Available Abstract Aim Amyloid A amyloidosis is a rare complication of chronic inflammatory conditions. Most patients with amyloid A amyloidosis present with nephropathy and it leads to renal failure and death. We studied clinical characteristics and survival in patients with amyloid A amyloidosis. Methods: A total of 81 patients (51 males, 30 females with renal biopsy proven amyloid A amyloidosis were analyzed retrospectively. The patients were divided into good and poor outcomes groups according to survival results. Results: Most of the patients (55.6% had nephrotic range proteinuria at diagnosis. Most frequent underlying disorders were familial Mediterranean fever (21.2% and rheumatoid arthritis (10.6% in the good outcome group and malignancy (20% in the poor outcome group. Only diastolic blood pressure in the good outcome group and phosphorus level in the poor outcome group was higher. Serum creatinine levels increased after treatment in both groups, while proteinuria in the good outcome group decreased. Increase in serum creatinine and decrease in estimated glomerular filtration rate of the poor outcome group were more significant in the good outcome group. At the time of diagnosis 18.5% and 27.2% of all patients had advanced chronic kidney disease (stage 4 and 5, respectively. Median duration of renal survival was 65 ± 3.54 months. Among all patients, 27.1% were started dialysis treatment during the follow-up period and 7.4% of all patients underwent kidney transplantation. Higher levels of systolic blood pressure [hazard ratios 1.03, 95% confidence interval: 1-1.06, p = 0.036], serum creatinine (hazard ratios 1.25, 95% confidence interval: 1.07-1.46, p = 0.006 and urinary protein excretion (hazard ratios 1.08, 95% confidence interval: 1.01-1.16, p = 0.027 were predictors of end-stage renal disease. Median survival of patients with organ involvement was 50.3 ± 16 months. Conclusion Our study indicated that familial Mediterranean fever constituted

Environmental and ecological conditions at Arctic breeding sites have limited effects on true survival rates of adult shorebirds

Science.gov (United States)

Weiser, Emily L.; Lanctot, Richard B.; Brown, Stephen C.; Gates, H. River; Bentzen, Rebecca L.; Bêty, Joël; Boldenow, Megan L.; English, Willow B.; Franks, Samantha E.; Koloski, Laura; Kwon, Eunbi; Lamarre, Jean-Francois; Lank, David B.; Liebezeit, Joseph R.; McKinnon, Laura; Nol, Erica; Rausch, Jennie; Saalfeld, Sarah T.; Senner, Nathan R.; Ward, David H.; Woodard, Paul F.; Sandercock, Brett K.

2018-01-01

Many Arctic shorebird populations are declining, and quantifying adult survival and the effects of anthropogenic factors is a crucial step toward a better understanding of population dynamics. We used a recently developed, spatially explicit Cormack–Jolly–Seber model in a Bayesian framework to obtain broad-scale estimates of true annual survival rates for 6 species of shorebirds at 9 breeding sites across the North American Arctic in 2010–2014. We tested for effects of environmental and ecological variables, study site, nest fate, and sex on annual survival rates of each species in the spatially explicit framework, which allowed us to distinguish between effects of variables on site fidelity versus true survival. Our spatially explicit analysis produced estimates of true survival rates that were substantially higher than previously published estimates of apparent survival for most species, ranging from S = 0.72 to 0.98 across 5 species. However, survival was lower for the arcticolasubspecies of Dunlin (Calidris alpina arcticola; S = 0.54), our only study taxon that migrates through the East Asian–Australasian Flyway. Like other species that use that flyway, arcticola Dunlin could be experiencing unsustainably low survival rates as a result of loss of migratory stopover habitat. Survival rates of our study species were not affected by timing of snowmelt or summer temperature, and only 2 species showed minor variation among study sites. Furthermore, although previous reproductive success, predator abundance, and the availability of alternative prey each affected survival of one species, no factors broadly affected survival across species. Overall, our findings of few effects of environmental or ecological variables suggest that annual survival rates of adult shorebirds are generally robust to conditions at Arctic breeding sites. Instead, conditions at migratory stopovers or overwintering sites might be driving adult survival rates and should be the

Survival Rate of Limb Replantation in Different Age Groups.

Science.gov (United States)

Tatebe, Masahiro; Urata, Shiro; Tanaka, Kenji; Kurahashi, Toshikazu; Takeda, Shinsuke; Hirata, Hitoshi

2017-08-01

Revascularization of damaged limbs/digits is technically feasible, but indications for surgical replantation remain controversial. The authors analyzed the survival rate of upper limb amputations and the associated factors in different age groups. They grouped 371 limb/digit amputees (average age, 44 years; range, 2-85 years) treated in their hospital during the past 10 years into three groups based on age (young, ≤ 15 years, n  = 12; adult, 16-64 years, n  = 302; elderly, ≥ 65 years, n  = 57) and analyzed their injury type (extent of injury and stump status), operation method, presence of medical complications (Charlson comorbidity index), and survival rate. There were 168 replantations, and the overall replantation survival rate was 93%. The Charlson comorbidity index of the replantation patients was 0 in 124 cases; 1 in 32; 2 in 9; and 3 in 3, but it did not show any significant difference in survival rate after replantation. Eight elderly patients (14%) did not opt for replantation. Younger patients tended to undergo replantation, but they had lower success rates due to their severe injury status. The results of this study show that the survival rate of replantation in elderly patients is equal to that in adults. Stump evaluation is important for survival, but the presence of medical complications is not associated with the overall survival rate.

Key factors influencing lung cancer survival in northern Italy.

Science.gov (United States)

Mangone, Lucia; Minicozzi, Pamela; Vicentini, Massimo; Giacomin, Adriano; Caldarella, Adele; Cirilli, Claudia; Falcini, Fabio; Giorgi Rossi, Paolo; Sant, Milena

2013-06-01

Lung cancer is a major cause of cancer death worldwide. The aims of this study were to analyze presentation, treatment and survival for lung cancer in northern Italy, and identify factors influencing survival. A total of 1180 lung cancer cases diagnosed in four north Italian cancer registries (Biella, Modena, Reggio Emilia, Romagna) in 2003-2005 were analyzed. Information on morphology, stage, diagnostic examinations, chemotherapy, radiotherapy, and surgical treatment was collected from clinical records. Three-year relative survival and relative excess risks of death were estimated. Overall, 10% of cases were stage I, 50% stage IV, and 12% stage unknown. Romagna - where sophisticated diagnostic examinations were performed more often - had proportionately more microscopically verified cases and resected cases than Biella. Romagna had also high proportions of cases given chemotherapy and radiotherapy. Three-year survival was 14%, range 10% (Biella) to 19% (Romagna); 69% for stage I, 3% for stage IV. Stage I survival was higher in Romagna (82%) than Reggio Emilia and Biella (60-61%) but for operated stage I cases, survival was similar (88%) in Romagna and Biella. The fully adjusted model showed a higher risk of death in Biella (1.23, 95%CI 1.02-1.48) than Modena (reference). Stage and surgery are key factors influencing survival. Centralizing lung cancer treatment to improve diagnostic work-up may improve outcomes. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

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

Ambulation and survival following surgery in elderly patients with metastatic epidural spinal cord compression.

Science.gov (United States)

Itshayek, Eyal; Candanedo, Carlos; Fraifeld, Shifra; Hasharoni, Amir; Kaplan, Leon; Schroeder, Josh E; Cohen, José E

2017-12-28

Metastatic epidural spinal cord compression (MESCC) is a disabling consequence of disease progression. Surgery can restore/preserve physical function, improving access to treatments that increase duration of survival; however, advanced patient age may deter oncologists and surgeons from considering surgical management. Evaluate the duration of ambulation and survival in elderly patients following surgical decompression of MESCC. Retrospective file review of a prospective database, under IRB waiver of informed consent, of consecutive patients treated in an academic tertiary care medical center from 8/2008-3/2015. Patients ≥65 years presenting neurological and/or radiological signs of cord compression due to metastatic disease, who underwent surgical decompression. Duration of ambulation and survival. Patients underwent urgent multidisciplinary evaluation and surgery. Ambulation and survival were compared with age, pre- and postoperative neurological (American Spinal Injury Association [ASIA] Impairment Scale [AIS]) and performance status (Karnofsky Performance Status [KPS], and Tokuhashi Score using Kruskal-Wallis and Wilcoxon signed-rank tests, Pearson correlation coefficient, Cox regression model, log rank analysis, and Kaplan Meir analysis. 40 patients were included (21 male, 54%; mean age 74 years, range 65-87). Surgery was performed a mean 3.8 days after onset of motor symptoms. Mean duration of ambulation and survival were 474 (range 0-1662) and 525 days (range 11-1662), respectively; 53% of patients (21/40) survived and 43% (17/40) retained ambulation for ≥1 year. There was no significant relationship between survival and ambulation for patients aged 65-69, 70-79, or 80-89, although Kaplan Meier analysis suggested stratification. There was a significant relationship between duration of ambulation and pre- and postoperative AIS (p=0.0342, p=0.0358, respectively) and postoperative KPS (p=0.0221). Tokuhashi score was not significantly related to duration of

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.

Real-time multi-target ranging based on chaotic polarization laser radars in the drive-response VCSELs.

Science.gov (United States)

Zhong, Dongzhou; Xu, Geliang; Luo, Wei; Xiao, Zhenzhen

2017-09-04

According to the principle of complete chaos synchronization and the theory of Hilbert phase transformation, we propose a novel real-time multi-target ranging scheme by using chaotic polarization laser radar in the drive-response vertical-cavity surface-emitting lasers (VCSELs). In the scheme, to ensure each polarization component (PC) of the master VCSEL (MVCSEL) to be synchronized steadily with that of the slave VCSEL, the output x-PC and y-PC from the MVCSEL in the drive system and those in the response system are modulated by the linear electro-optic effect simultaneously. Under this condition, by simulating the influences of some key parameters of the system on the synchronization quality and the relative errors of the two-target ranging, related operating parameters can be optimized. The x-PC and the y-PC, as two chaotic radar sources, are used to implement the real-time ranging for two targets. It is found that the measured distances of the two targets at arbitrary position exhibit strong real-time stability and only slight jitter. Their resolutions are up to millimeters, and their relative errors are very small and less than 2.7%.

Smothering in UK free-range flocks. Part 1: incidence, location, timing and management.

Science.gov (United States)

Barrett, J; Rayner, A C; Gill, R; Willings, T H; Bright, A

2014-07-05

Smothering in poultry is an economic and welfare-related concern. This study presents the first results from a questionnaire addressing the incidence, location, timing and management of smothering of free-range farm managers from two commercial egg companies (representing 35 per cent of the UK free-range egg supply). Overall, nearly 60 per cent of farm mangers experienced smothering in their last flock, with an average of 25.5 birds lost per incidence, although per cent mortality due to smothering was low (x̄=1.6 per cent). The majority of farm managers also reported that over 50 per cent of all their flocks placed had been affected by smothering. The location and timing of smothering (excluding smothering in nest boxes) tended to be unpredictable and varied between farms. Blocking off corners/nest boxes and walking birds more frequently were identified as popular smothering reduction measures, although there was a wide variety of reduction measures reported overall. The motivation to implement reduction measures was related to a farm manager's previous experience of smothering. To our knowledge, this is the first study to provide a representative industry estimate on the incidence, location, timing and management of smothering. The results suggest that smothering is a common problem, unpredictable between flocks with no clear, effective reduction strategies. A follow-up study will investigate the correlations among smothering, disease and other welfare problems and may shed further light on management solutions. British Veterinary Association.

Effects of Oral Administration of Fucoidan Extracted from Cladosiphon okamuranus on Tumor Growth and Survival Time in a Tumor-Bearing Mouse Model

Directory of Open Access Journals (Sweden)

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.

Survival in pediatric medulloblastoma: a population-based observational study to improve prognostication.

Science.gov (United States)

Weil, Alexander G; Wang, Anthony C; Westwick, Harrison J; Ibrahim, George M; Ariani, Rojine T; Crevier, Louis; Perreault, Sebastien; Davidson, Tom; Tseng, Chi-Hong; Fallah, Aria

2017-03-01

Medulloblastoma is the most common form of brain malignancy of childhood. The mainstay of epidemiological data regarding childhood medulloblastoma is derived from case series, hence population-based studies are warranted to improve the accuracy of survival estimates. To utilize a big-data approach to update survival estimates in a contemporary cohort of children with medulloblastoma. We performed a population-based retrospective observational cohort study utilizing the Surveillance, Epidemiology, and End Results Program database that captures all children, less than 20 years of age, between 1973 and 2012 in 18 geographical regions representing 28% of the US population. We included all participants with a presumed or histologically diagnosis of medulloblastoma. The main outcome of interest is survivors at 1, 5 and 10 years following diagnosis. A cohort of 1735 children with a median (interquartile range) age at diagnosis of 7 (4-11) years, with a diagnosis of medulloblastoma were identified. The incidence and prevalence of pediatric medulloblastoma has remained stable over the past 4 decades. There is a critical time point at 1990 when the overall survival has drastically improved. In the contemporary cohort (1990 onwards), the percentage of participants alive was 86, 70 and 63% at 1, 5 and 10 years, respectively. Multivariate Cox-Regression model demonstrated Radiation (HR 0.37; 95% CI 0.30-0.46, p < 0.001) and Surgery (HR 0.42; 95% CI 0.30-0.58, p < 0.001) independently predict survival. The probability of mortality from a neurological cause is <5% in patients who are alive 8 years following diagnosis. The SEER cohort analysis demonstrates significant improvements in pediatric medulloblastoma survival. In contrast to previous reports, the majority of patients survive in the modern era, and those alive 8 years following initial diagnosis are likely a long-term survivor. The importance of minimizing treatment-related toxicity is increasingly apparent given

Survival Analysis of Patients with End Stage Renal Disease

Science.gov (United States)

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.

Transcatheter arterial chemoembolization combined with radiofrequency ablation can improve survival of patients with hepatocellular carcinoma with portal vein tumour thrombosis: Extending the indication for ablation?

International Nuclear Information System (INIS)

Zheng, J.-S.; Long, J.; Sun, B.; Lu, N.-N.; Fang, D.; Zhao, L.-Y.; Du, N.

2014-01-01

Aim: To retrospectively assess long-term survival benefit and safety of transcatheter arterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) in hepatocellular carcinoma (HCC) patients with portal vein tumour thrombosis (PVTT), and to evaluate factors that significantly affect outcomes of these patients. Materials and methods: One hundred and thirty-four HCC patients (118 men and 16 women; mean age 54.8 years, range 26–79 years) with PVTT were retrospectively assessed. Patients were treated with TACE combined with RFA. Data analysed included patient demographics, liver volume, Child–Pugh score, and Cancer of the Liver Italian Programme (CLIP) score and imaging findings. Survival time (from occurrence of PVTT to last follow-up) was calculated using the Kaplan–Meier method, predictive factors and its correlation with survival was assessed using the multivariate Cox proportional hazards regression method. Results: The median overall survival (OS) time was 29.5 months (range 16.6–42.4 months), the 1, 3, and 5 year OS were 63%, 40%, and 23%. Cox hazards regression analysis revealed that functional remnant liver volume (FRLV), remnant liver volume (RLV)/total liver volume (TLV), radiation, tumour number, vascular endothelial growth factor (VEGF) distribution, and gross type were the only independent predictive factors of outcome (p = 0.039, 0.010, 0.009, 0.034, 0.031, and 0.000, respectively). Conclusion: TACE combined with RFA was found to be an effective therapy, FRLV and RLV/TLV have close correlation with survival for HCC patients with PVTT type I, II, or partial III and Child–Pugh A or B