159 research outputs found

    A robust data cleaning procedure for eddy covariance flux measurements

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    Abstract. The sources of systematic error responsible for introducing significant biases in the eddy covariance (EC) flux computation are manifold, and their correct identification is made difficult by the lack of reference values, by the complex stochastic dynamics, and by the high level of noise characterizing raw data. This work contributes to overcoming such challenges by introducing an innovative strategy for EC data cleaning. The proposed strategy includes a set of tests aimed at detecting the presence of specific sources of systematic error, as well as an outlier detection procedure aimed at identifying aberrant flux values. Results from tests and outlier detection are integrated in such a way as to leave a large degree of flexibility in the choice of tests and of test threshold values, ensuring scalability of the whole process. The selection of best performing tests was carried out by means of Monte Carlo experiments, whereas the impact on real data was evaluated on data distributed by the Integrated Carbon Observation System (ICOS) research infrastructure. Results evidenced that the proposed procedure leads to an effective cleaning of EC flux data, avoiding the use of subjective criteria in the decision rule that specifies whether to retain or reject flux data of dubious quality. We expect that the proposed data cleaning procedure can serve as a basis towards a unified quality control strategy for EC datasets, in particular in centralized data processing pipelines where the use of robust and automated routines ensuring results reproducibility constitutes an essential prerequisite

    Ena/VASP Enabled is a highly processive actin polymerase tailored to self-assemble parallel-bundled F-actin networks with Fascin

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    Enabled/vasodilator-stimulated phosphoprotein (Ena/VASP) proteins are required for the formation and maintenance of filopodia, finger-like projections at the leading edge of migrating cells that are composed of parallel actin filaments bundled by Fascin. We imaged individual fluorescently labeled Drosophila Ena molecules on both single and Fascin-bundled actin filaments in vitro. Ena stimulates actin assembly by remaining continuously associated with the barbed end and increasing the elongation rate by approximately two- to threefold. Remarkably, the frequency and length of Ena’s processive runs are enhanced on filaments within a Fascin bundle, which drives a positive feedback cycle that allows the assembly of uniformly thick filopodia-like F-actin bundles composed of multiple filaments with aligned ends

    Enabled Negatively Regulates Diaphanous-Driven Actin Dynamics In Vitro and In Vivo

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    Actin regulators facilitate cell migration by controlling cell protrusion architecture and dynamics. As the behavior of individual actin regulators becomes clear, we must address why cells require multiple regulators with similar functions and how they cooperate to create diverse protrusions. We characterized Diaphanous (Dia) and Enabled (Ena) as a model, using complementary approaches: cell culture, biophysical analysis, and Drosophila morphogenesis. We found that Dia and Ena have distinct biochemical properties that contribute to the different protrusion morphologies each induces. Dia is a more processive, faster elongator, paralleling the long, stable filopodia it induces in vivo, while Ena promotes filopodia with more dynamic changes in number, length, and lifetime. Acting together, Ena and Dia induce protrusions distinct from those induced by either alone, with Ena reducing Dia-driven protrusion length and number. Consistent with this, EnaEVH1 binds Dia directly and inhibits DiaFH1FH2-mediated nucleation in vitro. Finally, Ena rescues hemocyte migration defects caused by activated Dia

    Abelson kinase acts as a robust, multifunctional scaffold in regulating embryonic morphogenesis

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    Abelson family kinases (Abl) are key regulators of cell behavior and the cytoskeleton during development and in leukemia. Abl's SH3, SH2, and tyrosine kinase domains are joined via a linker to an F-actin-binding domain (FABD). Research on Abl's roles in cell culture led to several hypotheses for its mechanism of action: 1) Abl phosphorylates other proteins, modulating their activity. 2) Abl directly regulates the cytoskeleton via its cytoskeletal interaction domains, and/or 3) Abl is a scaffold for a signaling complex. The importance of these roles during normal development remains untested. We tested these mechanistic hypotheses during Drosophila morphogenesis using a series of mutants to examine Abl's many cell biological roles. Strikingly, Abl lacking the FABD fully rescued morphogenesis, cell shape change, actin regulation, and viability, while kinase dead Abl, though reduced in function, retained substantial rescuing ability in some but not all Abl functions. We also tested the function of four conserved motifs in the linker region, revealing a key role for a conserved PXXP motif known to bind Crk and Abi. We propose Abl acts as a robust multi-domain scaffold with different protein motifs and activities contributing differentially to diverse cellular behaviors

    A literature review on surgery for cervical vagal schwannomas

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    Cervical vagal schwannoma is a benign, slow-growing mass, often asymptomatic, with a very low lifetime risk of malignant transformation in general population, but diagnosis is still a challenge. Surgical resection is the treatment of choice even if its close relationship with nerve fibres, from which it arises, threats vagal nerve preservation. We present a case report and a systematic review of literature. All studies on surgical resection of cervical vagal schwannoma have been reviewed. Papers matching the inclusion criteria (topic on surgical removal of cervical vagal schwannoma, English language, full text available) were selected. Fifty-three patients with vagal neck schwannoma submitted to surgery were identified among 22 studies selected. Female/male ratio was 1.5 and median age 44 years. Median diameter was 5 cm (range 2 to 10). Most schwannoma were asymptomatic (68.2%) and received an intracapsular excision (64.9%). Postoperative symptoms were reported in 22.6% of patients. Cervical vagal schwannoma is a benign pathology requiring surgical excision, but frequently postoperative complications can affect patients lifelong, so, surgical indications should be based carefully on the balance between risks and benefits

    Exploration of Long-Chain Vitamin E Metabolites for the Discovery of a Highly Potent, Orally Effective, and Metabolically Stable 5-LOX Inhibitor that Limits Inflammation.

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    Endogenous long-chain metabolites of vitamin E (LCMs) mediate immune functions by targeting 5-lipoxygenase (5-LOX) and increasing the systemic concentrations of resolvin E3, a specialized proresolving lipid mediator. SAR studies on semisynthesized analogues highlight α-amplexichromanol (27a), which allosterically inhibits 5-LOX, being considerably more potent than endogenous LCMs in human primary immune cells and blood. Other enzymes within lipid mediator biosynthesis were not substantially inhibited, except for microsomal prostaglandin E2 synthase-1. Compound 27a is metabolized by sulfation and β-oxidation in human liver-on-chips and exhibits superior metabolic stability in mice over LCMs. Pharmacokinetic studies show distribution of 27a from plasma to the inflamed peritoneal cavity and lung. In parallel, 5-LOX-derived leukotriene levels decrease, and the inflammatory reaction is suppressed in reconstructed human epidermis, murine peritonitis, and experimental asthma in mice. Our study highlights 27a as an orally active, LCM-inspired drug candidate that limits inflammation with superior potency and metabolic stability to the endogenous lead

    Cisplatin-based first-line treatment of elderly patients with advanced non-small-cell lung cancer: Joint analysis of MILES-3 and MILES-4 phase III trials

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    Purpose: To test the efficacy of adding cisplatin to first-line treatment for elderly patients with advanced non-small-cell lung cancer (NSCLC) within a combined analysis of two parallel phase III trials, MILES-3 and MILES-4. Patients and Methods: Patients with advanced NSCLC who were older than age 70 years with Eastern Cooperative Oncology Group performance status 0 to 1 were randomly assigned to gemcitabine or pemetrexed, without or with cisplatin. In each trial, 382 events were required to detect a hazard ratio (HR) of death of 0.75, with 80% power and two-tailed a of .05. Trials were closed prematurely because of slow accrual, but the joint database allowed us to analyze the efficacy of cisplatin on the basis of intention-to-treat and adjusted by trial, histotype, non-platinum companion drug, stage, performance status, sex, age, and size of the study center. Results: From March 2011 to August 2016, 531 patients (MILES-3, 299; MILES-4, 232) were assigned to gemcitabine or pemetrexed without (n = 268) or with cisplatin (n = 263). Median age was 75 years, 79% were male, and 70% had nonsquamous histology. At a median 2-year follow-up, 384 deaths and 448 progression-free survival events were recorded. Overall survival was not significantly prolonged with cisplatin (HR, 0.86; 95% CI, 0.70 to 1.05; P = .14) and global health status score of quality of life was not improved, whereas progression-free survival (HR, 0.76; 95% CI, 0.63 to 0.92; P = .005) and objective response rate (15.5% v 8.5%; P = .02) were significantly better. Significantly more severe hematologic toxicity, fatigue, and anorexia were found with cisplatin. Conclusion: The addition of cisplatin to single-agent chemotherapy does not significantly prolong overall survival, and it does not improve global health status score of quality of life in elderly patients with advanced NSCLC

    Dose intensity and efficacy of the combination of everolimus and exemestane (EVE/EXE) in a real-world population of hormone receptor-positive (ER+/PgR+), HER2-negative advanced breast cancer (ABC) patients: a multicenter Italian experience

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    Aim: This retrospective analysis focused on the effect of treatment with EVE/EXE in a real-world population outside of clinical trials. We examined the efficacy of this combination in terms of PFS and RR related to dose intensity (5 mg daily versus 10 mg daily) and tolerability. Methods: 163 HER2-negative ER+/PgR+ ABC patients, treated with EVE/EXE from May 2011 to March 2016, were included in the analysis. The primary endpoints were the correlation between the daily dose and RR and PFS, as well as an evaluation of the tolerability of the combination. Secondary endpoints were RR, PFS, and OS according to the line of treatment. Patients were classified into three different groups, each with a different dose intensity of everolimus (A, B, C). Results: RR was 29.8% (A), 27.8% (B) (p = 0.953), and not evaluable (C). PFS was 9 months (95% CI 7–11) (A), 10 months (95% CI 9–11) (B), and 5 months (95% CI 2–8) (C), p = 0.956. OS was 38 months (95% CI 24–38) (A), median not reached (B), and 13 months (95% CI 10–25) (C), p = 0.002. Adverse events were stomatitis 57.7% (11.0% grade 3–4), asthenia 46.0% (6.1% grade 3–4), hypercholesterolemia 46.0% (0.6% grade 3–4), and hyperglycemia 35.6% (5.5% grade 3–4). The main reason for discontinuation/interruption was grade 2–3 stomatitis. Conclusions: No correlation was found between dose intensity (5 vs. 10 mg labeled dose) and efficacy in terms of RR and PFS. The tolerability of the higher dose was poor in our experience, although this had no impact on efficacy
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