Predicting procedure duration of colorectal endoscopic submucosal dissection at Western endoscopy centers

Background and study aims Overcoming logistical obstacles for the implementation of colorectal endoscopic submucosal dissection (ESD) requires accurate prediction of procedure times. We aimed to evaluate existing and new prediction models for ESD duration.Patients and methods Records of all consecutive patients who underwent single, non-hybrid colorectal ESDs before 2020 at three Dutch centers were reviewed. The performance of an Eastern prediction model [GIE 2021;94(1):133–144] was assessed in the Dutch cohort. A prediction model for procedure duration was built using multivariable linear regression. The model’s performance was validated using internal validation by bootstrap resampling, internal-external cross-validation and external validation in an independent Swedish ESD cohort.Results A total of 435 colorectal ESDs were analyzed (92% en bloc resections, mean duration 139 minutes, mean tumor size 39 mm). The performance of current unstandardized time scheduling practice was suboptimal (explained variance: R2=27%). We successfully validated the Eastern prediction model for colorectal ESD duration <60 minutes (c-statistic 0.70, 95% CI 0.62–0.77), but this model was limited due to dichotomization of the outcome and a relatively low frequency (14%) of ESDs completed <60 minutes in the Dutch centers. The model was more useful with a dichotomization cut-off of 120 minutes (c-statistic: 0.75; 88% and 17% of “easy” and “very difficult” ESDs completed <120 minutes, respectively). To predict ESD duration as continuous outcome, we developed and validated the six-variable cESD-TIME formula (https://cesdtimeformula.shinyapps.io/calculator/; optimism-corrected R2=61%; R2=66% after recalibration of the slope).Conclusions We provided two useful tools for predicting colorectal ESD duration at Western centers. Further improvements and validations are encouraged with potential local adaptation to optimize time planning

From Demonstrations to Task-Space Specifications:Using Causal Analysis to Extract Rule Parameterization from Demonstrations

Learning models of user behaviour is an important problem that is broadly applicable across many application domains requiring human-robot interaction. In this work, we show that it is possible to learn generative models for distinct user behavioural types, extracted from human demonstrations, by enforcing clustering of preferred task solutions within the latent space. We use these models to differentiate between user types and to find cases with overlapping solutions. Moreover, we can alter an initially guessed solution to satisfy the preferences that constitute a particular user type by backpropagating through the learned differentiable models. An advantage of structuring generative models in this way is that we can extract causal relationships between symbols that might form part of the user's specification of the task, as manifested in the demonstrations. We further parameterize these specifications through constraint optimization in order to find a safety envelope under which motion planning can be performed. We show that the proposed method is capable of correctly distinguishing between three user types, who differ in degrees of cautiousness in their motion, while performing the task of moving objects with a kinesthetically driven robot in a tabletop environment. Our method successfully identifies the correct type, within the specified time, in 99% [97.8 - 99.8] of the cases, which outperforms an IRL baseline. We also show that our proposed method correctly changes a default trajectory to one satisfying a particular user specification even with unseen objects. The resulting trajectory is shown to be directly implementable on a PR2 humanoid robot completing the same task.Comment: arXiv admin note: substantial text overlap with arXiv:1903.0126

Salience-based selection: attentional capture by distractors less salient than the target

Current accounts of attentional capture predict the most salient stimulus to be invariably selected first. However, existing salience and visual search models assume noise in the map computation or selection process. Consequently, they predict the first selection to be stochastically dependent on salience, implying that attention could even be captured first by the second most salient (instead of the most salient) stimulus in the field. Yet, capture by less salient distractors has not been reported and salience-based selection accounts claim that the distractor has to be more salient in order to capture attention. We tested this prediction using an empirical and modeling approach of the visual search distractor paradigm. For the empirical part, we manipulated salience of target and distractor parametrically and measured reaction time interference when a distractor was present compared to absent. Reaction time interference was strongly correlated with distractor salience relative to the target. Moreover, even distractors less salient than the target captured attention, as measured by reaction time interference and oculomotor capture. In the modeling part, we simulated first selection in the distractor paradigm using behavioral measures of salience and considering the time course of selection including noise. We were able to replicate the result pattern we obtained in the empirical part. We conclude that each salience value follows a specific selection time distribution and attentional capture occurs when the selection time distributions of target and distractor overlap. Hence, selection is stochastic in nature and attentional capture occurs with a certain probability depending on relative salience

The role of community and population ecology in applying mycorrhizal fungi for improved food security.

The global human population is expected to reach ∼9 billion by 2050. Feeding this many people represents a major challenge requiring global crop yield increases of up to 100%. Microbial symbionts of plants such as arbuscular mycorrhizal fungi (AMF) represent a huge, but unrealized resource for improving yields of globally important crops, especially in the tropics. We argue that the application of AMF in agriculture is too simplistic and ignores basic ecological principals. To achieve this challenge, a community and population ecology approach can contribute greatly. First, ecologists could significantly improve our understanding of the determinants of the survival of introduced AMF, the role of adaptability and intraspecific diversity of AMF and whether inoculation has a direct or indirect effect on plant production. Second, we call for extensive metagenomics as well as population genomics studies that are crucial to assess the environmental impact that introduction of non-local AMF may have on native AMF communities and populations. Finally, we plead for an ecologically sound use of AMF in efforts to increase food security at a global scale in a sustainable manner

Expression of stabilized β-catenin in differentiated neurons of transgenic mice does not result in tumor formation

BACKGROUND: Medulloblastomas, embryonal tumors arising in the cerebellum, commonly contain mutations that activate Wnt signaling. To determine whether increased Wnt signaling in the adult CNS is sufficient to induce tumor formation, we created transgenic mice expressing either wild-type or activated β-catenin in the brain. METHODS: Wild-type and mutant human β-catenin transgenes were expressed under the control of a murine PrP promoter fragment that drives high level postnatal expression in the CNS. Mutant β-catenin was stabilized by a serine to phenylalanine alteration in codon 37. RESULTS: Expression of the mutant transgene resulted in an approximately two-fold increase in β-catenin protein levels in the cortex and cerebellum of adult animals. Immunohistochemical analysis revealed nuclear β-catenin in hippocampal, cortical and cerebellar neurons of transgenic animals but not in non-transgenic controls. Tail kinking was observed in some transgenic animals, but no CNS malformations or tumors were detected. CONCLUSIONS: No tumors or morphologic alterations were detected in the brains of transgenic mice expressing stabilized β-catenin, suggesting that postnatal Wnt signaling in differentiated neurons may not be sufficient to induce CNS tumorigenesis

Critical assessment of the elemental composition of Corning archeological reference glasses by LA-ICP-MS

Corning archeological reference glasses A, B, C, and D have been made to simulate different historic technologies of glass production and are used as standards in historic glass investigations. In this work, nanoseconds (193, 266 nm) and femtosecond (800 nm) laser ablation were used to study the elemental composition of Corning glasses using laser ablation inductively coupled plasma mass spectrometry. The determined concentrations of 26 oxides (Li2O, B2O3, Na2O, MgO, Al2O3, SiO2, P2O5, K2O, CaO, TiO2, V2O5, Cr2O3, MnO, Fe2O3, CoO, NiO, CuO, ZnO, Rb2O, SrO, ZrO2, SnO2, Sb2O5, BaO, PbO, Bi2O3) are compared with values reported in the literature. Results show variable discrepancies between the data, with the largest differences found for Cr2O3 in Corning A; Li2O, B2O3, and Cr2O3 in Corning B; and MnO, Sb2O5, Cr2O3, and Bi2O3 in Corning C. The best agreement between the measured and literature values was found for Corning D. However, even for this reference, glass re-evaluation of the data was necessary and new values for PbO, BaO, and Bi2O3 are proposed

Association between anemia and quality of life in a population sample of individuals with chronic obstructive pulmonary disease

BACKGROUND: Several studies investigated the association of anemia with health related quality of life (HRQL) in patients with chronic disease. However, there is little evidence regarding the association of anemia with HRQL in patients with chronic obstructive pulmonary disease (COPD). METHODS: This is a post-hoc analysis of a study which enrolled a population of adults aged 35–79 randomly selected from residents of Erie and Niagara Counties, NY, between 1996 and 2000. In addition to demographic information and physical measurements, we obtained spirometry data and hemoglobin levels. We used modified Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria to define COPD, and World Health Organization (WHO) criteria to define anemia. To assess HRQL we used the Short Form-36 (SF-36) to assess physical functioning (PF), physical component summary (PCS) measures and mental component summary (MCS) measures. RESULTS: In the entire study population (n = 2704), respondents with anemia had lower scores on the physical functioning domain [45.4 (SD10.9) vs. 49.2 (SD 9.1); p < 0.0001]. Among patients with COPD (n = 495) the PF scores (39.9 vs. 45.4) and the PCS (41.9 vs. 45.9) were significantly lower in individuals with anemia compared to those without. In multiple regression analysis, the association between hemoglobin and PCS was positive (regression coefficient 0.02, p = 0.003). There was no significant association of hemoglobin with PF scores or the mental component summary measure after adjusting for covariates in patients with COPD. CONCLUSION: In patients with moderate to very severe COPD anemia may be associated with worse HRQL. However, co-morbidities may explain part or all of this association in these patients

Endoscopic sclerotherapy compared with no specific treatment for the primary prevention of bleeding from esophageal varices. A randomized controlled multicentre trial [ISRCTN03215899]

BACKGROUND: Since esophageal variceal bleeding is associated with a high mortality rate, prevention of bleeding might be expected to result in improved survival. The first trials to evaluate prophylactic sclerotherapy found a marked beneficial effect of prophylactic treatment. These results, however, were not generally accepted because of methodological aspects and because the reported incidence of bleeding in control subjects was considered unusually high. The objective of this study was to compare endoscopic sclerotherapy (ES) with nonactive treatment for the primary prophylaxis of esophageal variceal bleeding in patients with cirrhosis. METHODS: 166 patients with esophageal varices grade II, III of IV according to Paquet's classification, with evidence of active or progressive liver disease and without prior variceal bleeding, were randomized to groups receiving ES (n = 84) or no specific treatment (n = 82). Primary end-points were incidence of bleeding and mortality; secondary end-points were complications and costs. RESULTS: During a mean follow-up of 32 months variceal bleeding occurred in 25% of the patients of the ES group and in 28% of the control group. The incidence of variceal bleeding for the ES and control group was 16% and 16% at 1 year and 33% and 29% at 3 years, respectively. The 1-year survival rate was 87% for the ES group and 84% for the control group; the 3-year survival rate was 62% for each group. In the ES group one death occurred as a direct consequence of variceal bleeding compared to 9 in the other group (p = 0.01, log-rank test). Complications were comparable for the two groups. Health care costs for patients assigned to ES were estimated to be higher. Meta-analysis of a large number of trials showed that the effect of prophylactic sclerotherapy is significantly related to the baseline bleeding risk. CONCLUSION: In the present trial, prophylactic sclerotherapy did not reduce the incidence of bleeding from varices in patients with liver cirrhosis and a low to moderate bleeding risk. Although sclerotherapy lowered mortality attributable to variceal bleeding, overall survival was not affected. The effect of prophylactic sclerotherapy seems dependent on the underlying bleeding risk. A beneficial effect can only be expected for patients with a high risk for bleeding

Measurement of the branching fraction and CP content for the decay B(0) -> D(*+)D(*-)

This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APS.We report a measurement of the branching fraction of the decay B0→D*+D*- and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4  fb-1 collected at the Υ(4S) resonance during 1999–2000, we have reconstructed 38 candidate signal events in the mode B0→D*+D*- with an estimated background of 6.2±0.5 events. From these events, we determine the branching fraction to be B(B0→D*+D*-)=[8.3±1.6(stat)±1.2(syst)]×10-4. The measured CP-odd fraction of the final state is 0.22±0.18(stat)±0.03(syst).This work is supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the A.P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation

Identification of Hyaloperonospora arabidopsidis Transcript Sequences Expressed during Infection Reveals Isolate-Specific Effectors

Biotrophic plant pathogens secrete effector proteins that are important for infection of the host. The aim of this study was to identify effectors of the downy mildew pathogen Hyaloperonospora arabidopsidis (Hpa) that are expressed during infection of its natural host Arabidopsis thaliana. Infection-related transcripts were identified from Expressed Sequence Tags (ESTs) derived from leaves of the susceptible Arabidopsis Ws eds1-1 mutant inoculated with the highly virulent Hpa isolate Waco9. Assembly of 6364 ESTs yielded 3729 unigenes, of which 2164 were Hpa-derived. From the translated Hpa unigenes, 198 predicted secreted proteins were identified. Of these, 75 were found to be Hpa-specific and six isolate Waco9-specific. Among 42 putative effectors identified there were three Elicitin-like proteins, 16 Cysteine-rich proteins and 18 host-translocated RXLR effectors. Sequencing of alleles in different Hpa isolates revealed that five RXLR genes show signatures of diversifying selection. Thus, EST analysis of Hpa-infected Arabidopsis is proving to be a powerful method for identifying pathogen effector candidates expressed during infection. Delivery of the Waco9-specific protein RXLR29 in planta revealed that this effector can suppress PAMP-triggered immunity and enhance disease susceptibility. We propose that differences in host colonization can be conditioned by isolate-specific effectors