26 research outputs found
Allelopathic inhibition of primary producer growth and photosynthesis by aquatic fungi
Autochthonous primary production is generally much reduced in forested headwater streams. Several hypotheses have been proposed for explaining this observation, among them, the low light intensity, or the strong constraints exerted by stream current. Allelopathic inhibition of competitors is a common ecological process in aquatic environments. Aquatic hyphomycetes are known to chemically inhibit bacteria and other fungi (including other aquatic hyphomycetes) but a possible allelopathic effect of aquatic hyphomycetes on primary producers has never been tested. The inhibitory effect of twelve aquatic hyphomycete species was tested on three diatom species. Nine aquatic hyphomycete species exhibited anti-diatom activity. Up to 100% diatom growth inhibition was observed. Our study reveals that such allelopathic interactions might be common in streams and probably involve an array of fungal compounds. We propose that the generally reduced primary production observed in forested headwater streams is, among other factors, due to the inhibition of primary producers by allelopathic compounds released by aquatic hyphomycetes
Prognostic Value of Routinely Measured Inflammatory Biomarkers in Older Cancer Patients: Pooled Analysis of Three Cohorts
BACKGROUND: The prognostic assessment of older cancer patients is complicated by their heterogeneity. We aimed to assess the prognostic value of routine inflammatory biomarkers. METHODS: A pooled analysis of prospective multicenter cohorts of cancer patients aged >/=70 was performed. We measured CRP and albumin, and calculated Glasgow Prognostic Score (GPS) and CRP/albumin ratio. The GPS has three levels (0 = CRP /= 35 g/L, i.e., normal values; 1 = one abnormal value; 2 = two abnormal values). One-year mortality was assessed using Cox models. Discriminative power was assessed using Harrell's C index (C) and net reclassification improvement (NRI). RESULTS: Overall, 1800 patients were analyzed (mean age: 79 +/- 6; males: 62%; metastases: 38%). The GPS and CRP/albumin ratio were independently associated with mortality in patients not at risk of frailty (hazard ratio [95% confidence interval] = 4.48 [2.03-9.89] for GPS1, 11.64 [4.54-29.81] for GPS2, and 7.15 [3.22-15.90] for CRP/albumin ratio > 0.215) and in patients at risk of frailty (2.45 [1.79-3.34] for GPS1, 3.97 [2.93-5.37] for GPS2, and 2.81 [2.17-3.65] for CRP/albumin ratio > 0.215). The discriminative power of the baseline clinical model (C = 0.82 [0.80-0.83]) was increased by adding GPS (C = 0.84 [0.82-0.85]; NRI events (NRI+) = 10% [2-16]) and CRP/albumin ratio (C = 0.83 [0.82-0.85]; NRI+ = 14% [2-17]). CONCLUSIONS: Routine inflammatory biomarkers add prognostic value to clinical factors in older cancer patients
14 Examples of How LLMs Can Transform Materials Science and Chemistry: A Reflection on a Large Language Model Hackathon
Chemistry and materials science are complex. Recently, there have been great
successes in addressing this complexity using data-driven or computational
techniques. Yet, the necessity of input structured in very specific forms and
the fact that there is an ever-growing number of tools creates usability and
accessibility challenges. Coupled with the reality that much data in these
disciplines is unstructured, the effectiveness of these tools is limited.
Motivated by recent works that indicated that large language models (LLMs)
might help address some of these issues, we organized a hackathon event on the
applications of LLMs in chemistry, materials science, and beyond. This article
chronicles the projects built as part of this hackathon. Participants employed
LLMs for various applications, including predicting properties of molecules and
materials, designing novel interfaces for tools, extracting knowledge from
unstructured data, and developing new educational applications.
The diverse topics and the fact that working prototypes could be generated in
less than two days highlight that LLMs will profoundly impact the future of our
fields. The rich collection of ideas and projects also indicates that the
applications of LLMs are not limited to materials science and chemistry but
offer potential benefits to a wide range of scientific disciplines
Model Cortical Association Fields Account for the Time Course and Dependence on Target Complexity of Human Contour Perception
Can lateral connectivity in the primary visual cortex account for the time dependence and intrinsic task difficulty of human contour detection? To answer this question, we created a synthetic image set that prevents sole reliance on either low-level visual features or high-level context for the detection of target objects. Rendered images consist of smoothly varying, globally aligned contour fragments (amoebas) distributed among groups of randomly rotated fragments (clutter). The time course and accuracy of amoeba detection by humans was measured using a two-alternative forced choice protocol with self-reported confidence and variable image presentation time (20-200 ms), followed by an image mask optimized so as to interrupt visual processing. Measured psychometric functions were well fit by sigmoidal functions with exponential time constants of 30-91 ms, depending on amoeba complexity. Key aspects of the psychophysical experiments were accounted for by a computational network model, in which simulated responses across retinotopic arrays of orientation-selective elements were modulated by cortical association fields, represented as multiplicative kernels computed from the differences in pairwise edge statistics between target and distractor images. Comparing the experimental and the computational results suggests that each iteration of the lateral interactions takes at least ms of cortical processing time. Our results provide evidence that cortical association fields between orientation selective elements in early visual areas can account for important temporal and task-dependent aspects of the psychometric curves characterizing human contour perception, with the remaining discrepancies postulated to arise from the influence of higher cortical areas
Diagnosis of Postoperative Urinary Retention Using a Simplified Ultrasound Bladder Measurement
International audienceBACKGROUND:In this study, we sought to determine whether a simplified ultrasound measurement of the largest transverse diameter, using a standard ultrasound machine, could be used to diagnose postoperative urinary retention (POUR). This method may replace expensive bladder volume measuring devices or a more complex ultrasound procedure (involving the measurement of 3 bladder diameters).METHODS:Patients at risk of POUR if unable to void after orthopedic surgery were evaluated in the postanesthesia care unit before discharge. Bladder diameter was first measured using a portable ultrasound device (Vscan®; GE Healthcare, Wauwatosa, WI). An automated evaluation of bladder volume was then performed (Bladderscan® BVI 3000; Diagnostic Ultrasound, Redmond, WA). Finally, when a bladder catheterization was performed, the actual urinary volume was measured. The main outcome was a bladder volume ≥600 mL as measured using the automated ultrasound scanner (Bladderscan BVI 3000) or by catheterization. Correlations between bladder volumes and diameter were studied and receiver operating characteristic curves were constructed to determine the performance in predicting a bladder volume ≥600 mL. A "gray zone" approach was developed because a single cutoff value may not always be clinically significant.RESULTS:One hundred patients were included and underwent a Bladderscan measurement. Urinary volume after catheterization was obtained in 49 patients. A significant correlation was found between the largest transverse diameter and urinary volumes assessed by the 2 methods (Bladderscan and catheterization). Pearson correlation coefficients were r = 0.80 (95% confidence interval [CI], 0.72-0.86; P < 0.001) and r = 0.79 (95% CI, 0.65-0.88; P < 0.001), respectively. The area under the receiver operating characteristic curves for the prediction of a bladder volume ≥600 mL were 0.94 (95% CI, 0.88-0.98) and 0.91 (95% CI, 0.79-0.97), respectively, for urinary volumes assessed by Bladderscan and catheterization. The optimal cutoff value was 9.7 cm for both methods. The gray zone was narrow, ranging from 9.7 to 10.7 cm thus limiting inconclusive measurements.CONCLUSIONS:A simple ultrasound measurement of the largest transverse bladder diameter seemed to be helpful to exclude or confirm POUR
Biomarker Testing in Older Patients Treated for an Advanced or Metastatic Non-Squamous Non-Small-Cell Lung Cancer: The French ESME Real-Life Multicenter Cohort Experience
Background: Genomic and immunologic tumor biomarker testing has dramatically changed the prognosis of patients, particularly those treated for advanced/metastatic non-squamous non-small-cell lung cancer (aNSCLC) when access to targeted agents is available. It remains unclear whether older patients have access to therapy-predictive biomarker testing techniques in the same proportion as younger patients. This study aims to compare the proportion of biomarker testing performed in non-squamous aNSCLC at diagnosis between patients aged ≥70 years old and their younger counterparts. Methods: We conducted a retrospective analysis using the Epidemio-Strategy and Medical Economics (ESME) Advanced or Metastatic Lung Cancer Data Platform, a French multicenter real-life database. All patients with non-squamous aNSCLC diagnosed between 2015 and 2018 were selected. Biomarker testing corresponded to at least one molecular alteration and/or PD-L1 testing performed within 1 month before or 3 months after the aNSCLC diagnosis. Results: In total, 2848 patients aged ≥70 years and 6900 patients aged <70 years were included. Most patients were male. The proportion of current smokers at diagnosis was higher in the <70 years group (42% vs. 17%, p < 0.0001). There was no significant difference in the proportion of biomarker testing performed between the two groups (63% vs. 65%, p = 0.15). EGFR mutations were significantly more common in the older group (22% vs. 12%, p < 0.0001) and KRAS mutations significantly more frequent in the younger group (39% vs. 31% p < 0.0001). The distribution of other driver mutations (ALK, ROS1, BRAF V600E, HER2, and MET) was similar across age. In the multivariable analysis, factors independently associated with biomarker testing were gender, smoking status, history of COPD, stage at primary diagnosis, and histological type. Conclusions: Age is not a barrier to biomarker testing in patients with aNSCLC
Complications and Discharge after Radical Cystectomy for Older Patients with Muscle-Invasive Bladder Cancer: The ELCAPA-27 Cohort Study
International audienceRadical cystectomy is the standard of care for localized bladder cancer but is associated with high morbidity and mortality rates—especially among older patients with comorbidities. The association between geriatric assessment parameters on post-operative complications and discharge has not previously been investigated. The present analysis of the Elderly Cancer Patient (ELCAPA) prospective cohort included all patients aged ≥70 having undergone a geriatric assessment and then radical cystectomy for localized muscle-invasive bladder cancer between 2007 and 2018. The primary endpoint was the proportion of patients with one or more complications in the first 30 days after cystectomy. The secondary endpoints were the length of hospital stay (LOS), the 30-day mortality, and discharge rates. Sixty-two patients (median age: 81; range: 79–83.8) were included. The 30-day complication rate was 73%, and 49% of the patients had experienced a major complication, according to the Clavien-Dindo classification. The 30-day mortality rate was 4%. None of the geriatric, oncological, or laboratory parameters were significantly associated with the occurrence or severity of complications. The median (interquartile range) LOS was 18 days (15–23) overall and was longer in patients with complications (19 days vs. 15 days in those without complications; p = 0.013). Thirty days after cystectomy, 25 patients (53%) had been discharged to home and 22 (47%) were still in a rehabilitation unit. In a univariate analysis, a Geriatric-8 score ≤ 14, a loss of one point on the Activities of Daily Living Scale, anemia, at least one grade ≥ 3 comorbidity on the Cumulative Illness Rating Scale-Geriatric, and an inpatient geriatric assessment were associated with a risk of not being discharged to home. In older patients having undergone a geriatric assessment, radical cystectomy is associated with a high complication rate, a longer LOS, and functional decline at 30 days
Geriatric impairments were directly and indirectly associated with mortality in older patients with cancer: a structural equation analysis
International audienceOBJECTIVE: We assessed the direct and indirect effects between six geriatric domains and 6- and 12-month mortality in older cancer patients. STUDY DESIGN AND SETTING: We included cancer patients aged ≥70 from the ELCAPA cohort, referred for geriatric assessment between 2007 and 2016. We used structural equation modelling to examine the interrelationships between six geriatric domains (function and mobility, nutrition, cognition, mood, comorbidities and polypharmacy, and social support) and the direct and indirect relationships between these domains, the cancer stage, site, and treatment on one hand and mortality on the other. RESULTS: The analysis included 1434 patients (mean age: 80 ± 5.6; women: 48%; main cancer sites: digestive tract (36.2%), urinary tract and prostate (26.6%), and breast (16.5%); metastatic cancer: 48%). Direct relationships to 6- and 12- month mortality were identified for functional impairment (standardized coefficient (SC): 0.37 (P<0.001) and 0.32 (P<0.001), respectively), poor nutritional status (SC: 0.11 (P=0.005) and 0.14 (P=0.001)), poor social support (SC=0.07 (P=0.08) and 0.09 (P=0.02)), cancer site, stage, and treatment. The effects of comorbidities, cognitive impairment and depression on mortality were mediated by functional and nutritional status. CONCLUSION: In older cancer patients, functional and nutritional impairments were the strongest direct prognostic geriatric factors for mortality
Prevalence of Four Sarcopenia Criteria in Older Patients with Cancer, and Their Predictive Value for 6-Month Mortality: The NutriAgeCancer National Prospective Cohort Study
International audienceOlder cancer patients have an elevated risk of sarcopenia. The aim was to estimate the prevalence of four criteria for sarcopenia case finding, assessment, diagnosis, and severity determination: abnormal strength, assistance with walking, rising from a chair, climbing stairs, and falls (SARC-F), low hand-grip strength (HGS), low arm circumference (AC, a muscle mass proxy), and low physical performance (PP). Sarcopenia (low HGS and AC) and severe sarcopenia (low HGS, AC, and PP) and their predictive values for 6-month mortality were estimated in the whole population and by metastatic status. We analyzed data from the NutriAgeCancer French nationwide study of cancer patients aged ≥70 referred for geriatric assessment before anti-cancer treatment. We performed Cox proportional hazards analysis for each criterion separately and all criteria combined. Overall, 781 patients from 41 geriatric oncology clinics were included (mean age: 83.1; females: 53%; main cancer types: digestive (29%) and breast (17%); metastases: 42%). The prevalence of abnormal SARC-F, low HGS, a low AC, low PP, sarcopenia, and severe sarcopenia were, respectively, 35.5%, 44.6%, 44.7%, 35.2%, 24.5%, and 11.7%. An abnormal SARC-F and/or low HGS, sarcopenia, and severe sarcopenia were associated with 6-month mortality in patients with metastases (adjusted hazard ratios [95% confidence interval]: 2.72 [1.34–5.49], 3.16 [1.48–6.75] and 6.41 [2.5–16.5], respectively). Sarcopenia was strongly predictive of 6-month mortality in patients with metastatic cancer