173 research outputs found
Fragility curves for reinforced concrete frames characterised by different regularity
This paper presents a comparison between fragility curves developed for regular and non-regular reinforced frames.
Three 3D reinforced concrete multi-story frames characterised by different regularity are analysed. These fragility
curves are developed through the “Cloud Analysis“ procedure, which evaluates the structural response via Non-Linear
Time History Analysis (NLTHA).
Both maximum inter-story drift and maximum chord-rotation demand/capacity ratio are used as Engineering
Demand Parameters, in which the chord-rotation capacity is calculated according to the Italian Code. To fully develop
the fragility curves, both structure-independent and structure-dependent scalar intensity measures are selected among
the most referred in practice and literature.
This work shows the influence of regularity on the damage levels of the three buildings. Furthermore, it shows the
uncertainties caused by the selection criteria for EDP thresholds, which are necessary for a correct representation of
the Limit State
Survey on non-linear cyclic responses of Unreinforced Masonry buildings by means of commercial finite-element codes
This work presents a comparison about the nonlinear cyclic response of unreinforced masonry structures obtained by using commercial calculation codes and on the base of the type of modeling approaches currently available. In particular, several elastoplastic modeling methodologies are considered, representative of a good part of the state of the art for this type of construction: mechanical-based concentrated plasticity macro-element (Tremuri), macro-element with diffuse fiber-based plasticity for flexure and concentrated springs for shear (SeismoStruct) and macro-element with phenomenological-based concentrated plasticity (NextFEM Designer). The purpose of the present research is to evaluate the ability of the different codes to represent the proper hysteretic response of masonry structures. To this aim, several experimental tests from literature are analyzed and compared; two different masonry panels, characterized by different resistant mechanisms, and an entire perforated wall have been studied through nonlinear cyclic static analyses. The reported comparison, mainly focused on the numerical cyclic behaviour exhibited by each computer program, is conducted on the basis of the path of the cycles obtained and on the amount of dissipated energy
Language in Economics and Accounting Research: The Role of Linguistic History
This paper investigates whether a consideration of linguistic history is important when studying the relationship between economic and linguistic behaviors. Several recent economic studies have suggested that differences between languages can affect the way people think and behave (linguistic relativity or Sapir–Whorf hypothesis). For example, the way a language obliges one to talk about the future might influence intertemporal decisions, such as a company’s earnings management. However, languages have historical relations that lead to shared features—they do not constitute independent observations. This can inflate correlations between variables if not dealt with appropriately (Galton’s problem). We discuss this problem and provide an overview of the latest methods to control linguistic history. We then provide an empirical demonstration of how Galton’s problem can bias results in an investigation of whether a company’s earnings management behavior is predicted by structural features of its employees’ language. We find a strong relationship when not controlling linguistic history, but the relationship disappears when controls are applied. In contrast, economic predictors of earnings management remain robust. Overall, our results suggest that careful consideration of linguistic history is important for distinguishing true causes from spurious correlations in economic behaviors
Directed evolution of a magnetic resonance imaging contrast agent for noninvasive imaging of dopamine
The development of molecular probes that allow in vivo imaging of neural signaling processes with high temporal and spatial resolution remains challenging. Here we applied directed evolution techniques to create magnetic resonance imaging (MRI) contrast agents sensitive to the neurotransmitter dopamine. The sensors were derived from the heme domain of the bacterial cytochrome P450-BM3 (BM3h). Ligand binding to a site near BM3h's paramagnetic heme iron led to a drop in MRI signal enhancement and a shift in optical absorbance. Using an absorbance-based screen, we evolved the specificity of BM3h away from its natural ligand and toward dopamine, producing sensors with dissociation constants for dopamine of 3.3–8.9 μM. These molecules were used to image depolarization-triggered neurotransmitter release from PC12 cells and in the brains of live animals. Our results demonstrate the feasibility of molecular-level functional MRI using neural activity–dependent sensors, and our protein engineering approach can be generalized to create probes for other targets.Charles A. Dana Foundation. Brain and Immuno-ImagingRaymond and Beverley Sackler FoundationNational Institutes of Health (U.S.) (grant R01-DA28299)National Institutes of Health (U.S.) (grant DP2-OD2441)National Institutes of Health (U.S.) (grant R01-GM068664)Jacobs Institute for Molecular Engineering for Medicine. Jacobs Institute for Molecular Engineering for MedicineNational Institutes of Health (U.S.) (grant R01-DE013023
Clonal interference of signaling mutations worsens prognosis in core-binding factor acute myeloid leukemia
Mutations in receptor tyrosine kinase/RAS signaling pathway genes are frequent in core-binding factor (CBF) acute myeloid leukemias (AMLs), but their prognostic relevance is debated. A subset of CBF AML patients harbors several signaling gene mutations. Genotyping of colonies and of relapse samples indicates that these arise in independent clones, thus defining a process of clonal interference (or parallel evolution). Clonal interference is pervasive in cancers, but the mechanisms underlying this process remain unclear, and its prognostic impact remains unknown. We analyzed a cohort of 445 adult and pediatric patients with CBF AML treated with intensive chemotherapy and with deep sequencing of 6 signaling genes (, , , , , ). A total of 152 (34%), 167 (38%), and 126 (28%) patients harbored no, a single, and multiple signaling clones (clonal interference), respectively. Clonal interference of signaling mutations was associated with older age ( = .004) and inv(16) subtype ( = .025) but not with white blood cell count or mutations in chromatin or cohesin genes. The median allele frequency of signaling mutations was 31% in patients with a single clone or clonal interference ( = .14). The repertoire of , , and / variants differed between groups. Clonal interference did not affect complete remission rate or minimal residual disease after 1-2 courses, but it did convey inferior event-free survival ( < 10), whereas the presence of a single signaling clone did not ( = .44). This inferior outcome was independent of clinical parameters and of the presence of specific signaling clones. Our results suggest that specific clonal architectures can herald distinct prognoses in AML
Clinical phenotypes and quality of life to define post-COVID-19 syndrome: a cluster analysis of the multinational, prospective ORCHESTRA cohort
Background Lack of specific definitions of clinical characteristics, disease severity, and risk and preventive factors of post-COVID-19 syndrome (PCS) severely impacts research and discovery of new preventive and therapeutics drugs.Methods This prospective multicenter cohort study was conducted from February 2020 to lune 2022 in 5 countries, enrolling SARS-CoV-2 out-and in-patients followed at 3-, 6-, and 12-month from diagnosis, with assessment of clinical and biochemical features, antibody (Ab) response, Variant of Concern (VoC), and physical and mental quality of life (QoL).Outcome of interest was identification of risk and protective factors of PCS by clinical phenotype, setting, severity of disease, treatment, and vaccination status. We used SF-36 questionnaire to assess evolution in QoL index during follow-up and unsupervised machine learning algorithms (principal component analysis, PCA) to explore symptom clusters. Severity of PCS was defined by clinical phenotype and QoL. We also used generalized linear models to analyse the impact of PCS on QoL and associated risk and preventive factors. CT registration number: NCT05097677.Findings Among 1796 patients enrolled, 1030 (57%) suffered from at least one symptom at 12-month. PCA identified 4 clinical phenotypes: chronic fatigue-like syndrome (CFs: fatigue, headache and memory loss, 757 patients, 42%), respiratory syndrome (REs: cough and dyspnoea, 502, 23%); chronic pain syndrome (CPs: arthralgia and myalgia, 399, 22%); and neurosensorial syndrome (NSs: alteration in taste and smell, 197, 11%). Determinants of clinical phenotypes were different (all comparisons p < 0.05): being female increased risk of CPs, NSs, and CFs; chronic pulmonary diseases of REs; neurological symptoms at SARS-CoV-2 diagnosis of REs, NSs, and CFs; oxygen therapy of CFs and REs; and gastrointestinal symptoms at SARS-CoV-2 diagnosis of CFs. Early treatment of SARS-CoV-2 infection with monoclonal Ab (all clinical phenotypes), corticosteroids therapy for mild/severe cases (NSs), and SARS-CoV-2 vaccination (CPs) were less likely to be associated to PCS (all comparisons p < 0.05). Highest reduction in QoL was detected in REs and CPs (43.57 and 43.86 vs 57.32 in PCS-negative controls, p < 0.001). Female sex (p < 0.001), gastrointestinal symptoms (p = 0.034) and renal complications (p = 0.002) during the acute infection were likely to increase risk of severe PCS (QoL <50). Vaccination and early treatment with monoclonal Ab reduced the risk of severe PCS (p = 0.01 and p = 0.03, respectively).Interpretation Our study provides new evidence suggesting that PCS can be classified by clinical phenotypes with different impact on QoL, underlying possible different pathogenic mechanisms. We identified factors associated to each clinical phenotype and to severe PCS. These results might help in designing pathogenesis studies and in selecting high-risk patients for inclusion in therapeutic and management clinical trials
Dietary practices in isovaleric acidemia:A European survey
Background: In Europe, dietary management of isovaleric acidemia (IVA) may vary widely. There is limited collective information about dietetic management. Aim: To describe European practice regarding the dietary management of IVA, prior to the availability of the E-IMD IVA guidelines (E-IMD 2014). Methods: A cross-sectional questionnaire was sent to all European dietitians who were either members of the Society for the Study of Inborn Errors of Metabolism Dietitians Group (SSIEM-DG) or whom had responded to previous questionnaires on dietetic practice (n=53). The questionnaire comprised 27 questions about the dietary management of IVA. Results: Information on 140 patients with IVA from 39 centres was reported. 133 patients (38 centres) were given a protein restricted diet. Leucine-free amino acid supplements (LFAA) were routinely used to supplement protein intake in 58% of centres. The median total protein intake prescribed achieved the WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Centres that prescribed LFAA had lower natural protein intakes in most age groups except 1 to 10 y. In contrast, when centres were not using LFAA, the median natural protein intake met WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Enteral tube feeding was rarely prescribed. Conclusions: This survey demonstrates wide differences in dietary practice in the management of IVA across European centres. It provides unique dietary data collectively representing European practices in IVA which can be used as a foundation to compare dietary management changes as a consequence of the first E-IMD IVA guidelines availability. (C) 2017 The Authors. Published by Elsevier Inc
Dietary practices in propionic acidemia:A European survey
Background: The definitive dietary management of propionic acidaemia (PA) is unknown although natural protein restriction with adequate energy provision is of key importance. Aim: To describe European dietary practices in the management of patients with PA prior to the publication of the European PA guidelines. Methods: This was a cross-sectional survey consisting of 27 questions about the dietary practices in PA patients circulated to European IMD dietitians and health professionals in 2014. Results: Information on protein restricted diets of 186 PA patients from 47 centres, representing 14 European countries was collected. Total protein intake [PA precursor-free L-amino acid supplements (PFAA) and natural protein] met WHO/FAO/UNU (2007) safe protein requirements for age in 36 centres (77%). PFAA were used to supplement natural protein intake in 81% (n = 38) of centres, providing a median of 44% (14-83%) of total protein requirement. Seventy-four per cent of patients were prescribed natural protein intakes below WHO/ FAO/UNU (2007) safe levels in one or more of the following age groups: 0-6 m, 7-12 m, 1-10 y, 11-16 y and > 16 y. Sixty-three per cent (n = 117) of patients were tube fed (74% gastrostomy), but only 22% received nocturnal feeds. Conclusions: There was high use of PFAA with intakes of natural protein commonly below WHO/FAO/UNU (2007) safe levels. Optimal dietary management can only be determined by longitudinal, multi-centre, prospective case controlled studies. The metabolic instability of PA and small patient cohorts in each centre ensure that this is a challenging undertaking
CEBPA-mutated leukemia is sensitive to genetic and pharmacological targeting of the MLL1 complex
The gene encoding the transcription factor C/EBP alpha is mutated in 10-15% of acute myeloid leukemia (AML) patients. N-terminal CEBPA mutations cause ablation of full-length C/EBP alpha without affecting the expression of a shorter oncogenic isoform, termed p30. The mechanistic basis of p30-induced leukemogenesis is incompletely understood. Here, we demonstrate that the MLL1 histone-methyltransferase complex represents a critical actionable vulnerability in CEBPA-mutated AML. Oncogenic C/EBP alpha p30 and MLL1 show global co-localization on chromatin and p30 exhibits robust physical interaction with the MLL1 complex. CRISPR/Cas9-mediated mutagenesis of MLL1 results in proliferation arrest and myeloid differentiation in C/EBP alpha p30-expressing cells. In line, CEBPA-mutated hematopoietic progenitor cells are hypersensitive to pharmacological targeting of the MLL1 complex. Inhibitor treatment impairs proliferation and restores myeloid differentiation potential in mouse and human AML cells with CEBPA mutations. Finally, we identify the transcription factor GATA2 as a direct critical target of the p30-MLL1 interaction. Altogether, we show that C/EBP alpha p30 requires the MLL1 complex to regulate oncogenic gene expression and that CEBPA-mutated AML is hypersensitive to perturbation of the MLL1 complex. These findings identify the MLL1 complex as a potential therapeutic target in AML with CEBPA mutations
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