307 research outputs found
Integrated information increases with fitness in the evolution of animats
One of the hallmarks of biological organisms is their ability to integrate
disparate information sources to optimize their behavior in complex
environments. How this capability can be quantified and related to the
functional complexity of an organism remains a challenging problem, in
particular since organismal functional complexity is not well-defined. We
present here several candidate measures that quantify information and
integration, and study their dependence on fitness as an artificial agent
("animat") evolves over thousands of generations to solve a navigation task in
a simple, simulated environment. We compare the ability of these measures to
predict high fitness with more conventional information-theoretic processing
measures. As the animat adapts by increasing its "fit" to the world,
information integration and processing increase commensurately along the
evolutionary line of descent. We suggest that the correlation of fitness with
information integration and with processing measures implies that high fitness
requires both information processing as well as integration, but that
information integration may be a better measure when the task requires memory.
A correlation of measures of information integration (but also information
processing) and fitness strongly suggests that these measures reflect the
functional complexity of the animat, and that such measures can be used to
quantify functional complexity even in the absence of fitness data.Comment: 27 pages, 8 figures, one supplementary figure. Three supplementary
video files available on request. Version commensurate with published text in
PLoS Comput. Bio
Complexity of multi-dimensional spontaneous EEG decreases during propofol induced general anaesthesia
Emerging neural theories of consciousness suggest a correlation between a specific type of neural dynamical complexity and the level of consciousness: When awake and aware, causal interactions between brain regions are both integrated (all regions are to a certain extent connected) and differentiated (there is inhomogeneity and variety in the interactions). In support of this, recent work by Casali et al (2013) has shown that Lempel-Ziv complexity correlates strongly with conscious level, when computed on the EEG response to transcranial magnetic stimulation. Here we investigated complexity of spontaneous high-density EEG data during propofol-induced general anaesthesia. We consider three distinct measures: (i) Lempel-Ziv complexity, which is derived from how compressible the data are; (ii) amplitude coalition entropy, which measures the variability in the constitution of the set of active channels; and (iii) the novel synchrony coalition entropy (SCE), which measures the variability in the constitution of the set of synchronous channels. After some simulations on Kuramoto oscillator models which demonstrate that these measures capture distinct ‘flavours’ of complexity, we show that there is a robustly measurable decrease in the complexity of spontaneous EEG during general anaesthesia
The Minimal Complexity of Adapting Agents Increases with Fitness
What is the relationship between the complexity and the fitness of evolved organisms, whether natural or artificial? It has been asserted, primarily based on empirical data, that the complexity of plants and animals increases as their fitness within a particular environment increases via evolution by natural selection. We simulate the evolution of the brains of simple organisms living in a planar maze that they have to traverse as rapidly as possible. Their connectome evolves over 10,000s of generations. We evaluate their circuit complexity, using four information-theoretical measures, including one that emphasizes the extent to which any network is an irreducible entity. We find that their minimal complexity increases with their fitness
Prevalence and natural history of potential coeliac disease in adult patients.
OBJECTIVE:
Potential celiac disease (PCD) is a form of CD characterized by positive endomysial/tissue transglutaminase antibodies and a preserved duodenal mucosa despite a gluten-containing diet (GCD); it can evolve into flat, active CD. This evolution is, however, not certain. Our aim was to retrospectively study the prevalence and the natural history of adult patients with PCD.
METHODS:
The clinical notes of all 47 patients with PCD attending our clinic between September 1999 and October 2011 were retrospectively reevaluated. To study their clinical features, patients with active CD, randomly selected and matched for sex and date of birth, served as controls. Symptoms, associated diseases, familiarity, and laboratory data at diagnosis were compared.
RESULTS:
Prevalence of PCD among all celiac patients directly diagnosed in our center was 42/187, (1/4.4, 18.3%, 95% confidence interval (CI) 13.3-23.4%). Age at diagnosis, laboratory data, prevalence of symptoms, associated diseases, and familiarity for CD did not differ between patients with PCD and those with active CD. Some patients with PCD maintained a normal duodenal mucosa for many years and their symptoms spontaneously improved despite maintaining a GCD.
CONCLUSIONS:
PCD is not a rare form of CD. Having found no difference at all in age at diagnosis and clinical features between PCD and active CD could suggest that PCD is not a prodrome of CD but is a separate entity that can only subsequently evolve into active CD
191pd_pr9 weeks versus 1 year adjuvant trastuzumab for her2 early breast cancer subgroup analysis of the shorther trial allows to identify patients for whom a shorter trastuzumab administration may have a favourable risk benefit ratio
n/
Nine-Week Versus One-Year Trastuzumab for Early Human Epidermal Growth Factor Receptor 2â € "Positive Breast Cancer: 10-Year Update of the ShortHER Phase III Randomized Trial
Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We present the final analysis of the phase III noninferiority, randomized ShortHER trial comparing 9 weeks versus 1 year of adjuvant trastuzumab with chemotherapy in patients with human epidermal growth factor receptor 2â € "positive (HER2+) early breast cancer (BC). Women with HER2+ BC were randomly assigned to anthracycline-taxane combinations plus 1-year trastuzumab (arm A, long) or 9-week trastuzumab (arm B, short). Here, we report the second coprimary end point overall survival (OS), updated disease-free survival (DFS), and outcomes according to hormone receptor status, age, and nodal status. At a median follow-up of 9 years, 10-year DFS is 77% versus 78% in the long versus short arm, respectively. Ten-year OS is 89% versus 88% in the long versus short arm, respectively. 10-year DFS rates in the long versus short arm according to nodal status are N0 81% versus 85%; N1-3 77% versus 79%; and N4+ 63% versus 53%. Ten-year OS rates in long versus short arm according to nodal status are N0 89% versus 95%%; N1-3 92% versus 89%; and N4+ 84% versus 64%. The updated analysis of the ShortHER trial shows that 1-year trastuzumab is the standard treatment for patients with HER2+ early BC as noninferiority cannot be claimed. However, numerically, the differences for the patients at low or intermediate risk (N0/N1-3) is negligible, while patients with N4+ have a clear benefit with 1-year trastuzumab
Association of tumor-infiltrating lymphocytes with distant disease-free survival in the ShortHER randomized adjuvant trial for patients with early HER2+ breast cancer.
BACKGROUND: There is the need to identify new prognostic markers to refine risk stratification for HER2-positive early breast cancer patients. The aim of this study was to evaluate the association of tumor-infiltrating lymphocytes (TILs) with distant disease-free survival (DDFS) in patients with HER2-positive early breast cancer enrolled in the ShortHER adjuvant trial which compared 9 weeks versus 1-year trastuzumab in addition to chemotherapy, and to test the interaction between TILs and treatment arm. PATIENTS AND METHODS: Stromal TILs were assessed for 866 cases on centralized hematoxylin and eosin-stained tumor slides. The association of TILs as 10% increments with DDFS was assessed with Cox models. Kaplan-Meier curves were estimated for patients with TILs\u2009 6520% and TILs\u2009<20%. Median follow-up was 6.1\u2009years. RESULTS: Median TILs was 5% (Q1-Q3 1%-15%). Increased TILs were independently associated with better DDFS in multivariable model [hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.59-0.89, P\u2009=\u20090.006, for each 10% TILs increment]. Five years DDFS rates were 91.1% for patients with TILs\u2009<20% and 95.7% for patients with TILs\u2009 6520% (P\u2009=\u20090.025). The association between 10% TILs increments and DDFS was significant for patients randomized to 9\u2009weeks of trastuzumab (HR 0.60, 95% CI 0.41-0.88) but not for patients treated with 1\u2009year of trastuzumab (HR 0.89, 95% CI 0.71-1.12; test for interaction P\u2009=\u20090.088). For patients with TILs\u2009<20%, the HR for the comparison between the short versus the long arm was 1.75 (95% CI 1.09-2.80, P=0.021); whereas, for patients with TILs\u2009 6520% the HR for the comparison of short versus long arm was 0.23 (95% CI 0.05-1.09, P\u2009=\u20090.064), resulting in a significant interaction (P\u2009=\u20090.015). CONCLUSIONS: TILs are an independent prognostic factor for HER2-positive early breast cancer patients treated with adjuvant chemotherapy and trastuzumab and may refine the ability to identify patients at low risk of relapse eligible for de-escalated adjuvant therapy
Shock Identification of Macroeconomic Forecasts Based on Daily Panels
This paper proposes a new procedure for shock identification of macroeconomic forecasts based on factor analysis. Our identification scheme for information shocks relies on data reduction techniques for daily panels and the recognition that macroeconomic releases exhibit a high level of clustering. A large number of data releases on a single day is of considerable practical interest not only for the estimation but also for the identification of the factor model. The clustering of cross-sectional information facilitates the interpretation of the forecast innovations as real or as nominal information shocks. An empirical application is provided for Swiss inflation. We show that (i) the monetary policy shocks generate an asymmetric response to inflation, (ii) the pass-through for consumer price index inflation is weak, and (iii) the information shocks to inflation are not synchronized
American Society of Hematology 2019 guidelines for management of venous thromboembolism : prevention of venous thromboembolism in surgical hospitalized patients
Background: Venous thromboembolism (VTE) is a common source of perioperative morbidity and mortality. Objective: These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about preventing VTE in patients undergoing surgery. Methods: ASH formed a multidisciplinary guideline panel balanced to minimize bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic reviews. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment. Results: The panel agreed on 30 recommendations, including for major surgery in general (n = 8), orthopedic surgery (n = 7), major general surgery (n = 3), major neurosurgical procedures (n = 2), urological surgery (n = 4), cardiac surgery and major vascular surgery (n = 2), major trauma (n = 2), and major gynecological surgery (n = 2). Conclusions: For patients undergoing major surgery in general, the panel made conditional recommendations for mechanical prophylaxis over no prophylaxis, for pneumatic compression prophylaxis over graduated compression stockings, and against inferior vena cava filters. In patients undergoing total hip or total knee arthroplasty, conditional recommendations included using either aspirin or anticoagulants, as well as for a direct oral anticoagulant over low-molecular-weight heparin (LMWH). For major general surgery, the panel suggested pharmacological prophylaxis over no prophylaxis, using LMWH or unfractionated heparin. For major neurosurgery, transurethral resection of the prostate, or radical prostatectomy, the panel suggested against pharmacological prophylaxis. For major trauma surgery or major gynecological surgery, the panel suggested pharmacological prophylaxis over no prophylaxis.Peer reviewe
Validation of the AJCC prognostic stage for HER2-positive breast cancer in the ShortHER trial .
BACKGROUND: The 8th edition of the American Joint Committee on Cancer (AJCC) staging has introduced prognostic stage based on anatomic stage combined with biologic factors. We aimed to validate the prognostic stage in HER2-positive breast cancer patients enrolled in the ShortHER trial. METHODS: The ShortHER trial randomized 1253 HER2-positive patients to 9 weeks or 1 year of adjuvant trastuzumab combined with chemotherapy. Patients were classified according to the anatomic and the prognostic stage. Distant disease-free survival (DDFS) was calculated from randomization to distant relapse or death. RESULTS: A total of 1244 patients were included. Compared to anatomic stage, the prognostic stage downstaged 41.6% (n\u2009=\u2009517) of patients to a more favorable stage category. Five-year DDFS based on anatomic stage was as follows: IA 96.6%, IB 94.1%, IIA 92.4%, IIB 87.3%, IIIA 81.3%, IIIC 70.5% (P\u2009<\u20090.001). Five-year DDFS according to prognostic stage was as follows: IA 95.7%, IB 91.4%, IIA 86.9%, IIB 85.0%, IIIA 77.6%, IIIC 67.7% (P\u2009<\u20090.001). The C index was similar (0.69209 and 0.69249, P\u2009=\u20090.975). Within anatomic stage I, the outcome was similar for patients treated with 9 weeks or 1 year trastuzumab (5-year DDFS 96.2% and 96.6%, P\u2009=\u20090.856). Within prognostic stage I, the outcome was numerically worse for patients treated with 9\u2009weeks trastuzumab (5-year DDFS 93.7% and 96.3%, P\u2009=\u20090.080). CONCLUSIONS: The prognostic stage downstaged 41.6% of patients, while maintaining a similar prognostic performance as the anatomic stage. The prognostic stage is valuable in counseling patients and may serve as reference for a clinical trial design. Our data do not support prognostic stage as guidance to de-escalate treatment
- …
