Search results for "Abstract"
showing 10 items of 1959 documents
Examination of the least-squares method applied to the evaluation of physicochemical parameters with linearized equations
1989
Physicochemical parameters are frequently evaluated by the least-squares method after linearization of the equation which relates the experimental variables to the parameters of interest. When a given set of data is treated to evaluate (n+1) parameters. (n+2) nominally identical linearized equations are possible; each of these leads to different sets of values of the parameters which are also affected by different variances. These differences are also observed when statistical weights are used. Two methods for establishing which one of the (n+2) equations is best for fitting the data, i.e., simulation of experiments and propagation of errors, are discussed, compared and applied to a potenti…
Data Treatment and Error Analysis in Kinetics
2000
Methods of data treatment in kinetics are reviewed from a practical viewpoint. The equations to describe the kinetics of chemical reactions and the methodology to obtain the models are presented. Moreover, the integration methods that are needed for the simulation of complex reactions are explained, from the simple first-order reaction to the complex general mechanism. However, it is essential to know the main sources of error in data treatment in order to reduce their effects on the results. Stress is put on the analysis of the errors due to the simplification of complex models. The different factors that influence the kinetics of the reaction are reviewed. How to take advantage of the kin…
Identification of new claudin family members by a novel PSI-BLAST based approach with enhanced specificity.
2006
In an attempt to develop a novel strategy for the identification of new members of protein families by in silico approaches, we have developed a semi-automated procedure of consecutive PSI-BLAST (Position-Specific-Iterated Basic Local Alignment Search Tool) searches incorporating identificiation as well as subsequent validation of putative candidates. For a proof of concept study we chose the search for novel members of the claudin family. The initial step was an iterated PSI-BLAST search starting with the PMP22_Claudin domain of each known member of the claudin family against the human part of the RefSeq Database. Putative new claudin domains derived from the converged list were evaluated …
Experimental Evaluation of Protein Secondary Structure Predictors
2009
Understanding protein biological function is a key issue in modern biology, which is largely determined by its 3D shape. Protein 3D shape, in its turn, is functionally implied by its amino acid sequence. Since the direct inspection of such 3D structures is rather expensive and time consuming, a number of software techniques have been developed in the last few years that predict a spatial model, either of the secondary or of the tertiary form, for a given target protein starting from its amino acid sequence. This paper offers a comparison of several available automatic secondary structure prediction tools. The comparison is of the experimental kind, where two relevant sets of proteins, a non…
A no-go result for the quantum damped harmonic oscillator
2019
Abstract In this letter we show that it is not possible to set up a canonical quantization for the damped harmonic oscillator using the Bateman Lagrangian. In particular, we prove that no square integrable vacuum exists for the natural ladder operators of the system, and that the only vacua can be found as distributions. This implies that the procedure proposed by some authors is only formally correct, and requires a much deeper analysis to be made rigorous.
A Constructive Arboricity Approximation Scheme
2020
The arboricity \(\varGamma \) of a graph is the minimum number of forests its edge set can be partitioned into. Previous approximation schemes were nonconstructive, i.e., they approximate the arboricity as a value without computing a corresponding forest partition. This is because they operate on pseudoforest partitions or the dual problem of finding dense subgraphs.
O4.8. CAN YOU SPOT EMOTIONS? FACIAL EMOTION RECOGNITION AND GENETIC RISK FOR PSYCHOSIS
2019
Background Facial emotion recognition (FER) is a key component of social cognition which has been found consistently impaired in schizophrenia. Deficits in global facial affect recognition have been also found in First Episode Psychosis (FEP) with the same severity as at further stages, especially for anger recognition. Literature to date has shown intermediate emotion recognition ability in either people with family history for psychotic disorders and unaffected relatives of psychotic patients, in a continuum between patients and healthy controls. Furthermore, Polygenic Risk Score (PRS) for schizophrenia has been found associated with social cognition, especially with facial emotion identi…
S153. WHERE IS THE ABNORMAL BRAIN ACTIVITY IN FIRST EPISODE PSYCHOSIS?
2018
Abstract Background Recent review about functional magnetic resonance imaging (fMRI) in first episode psychosis (FEP) concluded that there is an abnormal connectivity involving the frontal temporal pathway similar to found in chronic schizophrenia (Mwansisya et al., 2017). Besides, thalamic circuits were also altered in chronic schizophrenia patients (Li et al., 2017). The present work gives a wider review of studies using functional magnetic resonance imaging techniques (fMRI) on first-episode psychotic patients, specifically focus on the main areas involved. Methods The review was made in accordance with the PRISMA guidelines (Moher et al., 2009). For each study, the following factors wer…
F145. WHAT ARE THE MAIN BRAIN CHANGES IN FMRI AFTER TREATMENT IN FIRST EPISODE PSYCHOSIS? A SYSTEMATIC REVIEW
2018
Abstract Background There are many studies using structural MRI to explore the longitudinal course of F Episode Psychosis (FEP).2 On the other hand, there is a lack of functional MRI studies examining the longitudinal course of FEP. The aim of this work is to make a literature systematic review of these studies, to summarize the knowledge about longitudinal course of functional brain activity in FEP. Methods We followed the PRISMA guidelines for conducting systematic reviews and combined the use of electronic and manual systematic search methods, in the principal databases (MedLine, PubMed and Web of Science) using the query “longitudinal” AND “fMRI” AND “first episode psychosis” OR “first …
F99. FIRST EPISODE PSYCHOSIS PATIENTS WHO USED CANNABIS DEVELOP THEIR ILLNESS AT A SIGNIFICANTLY YOUNGER AGE THAN THOSE WHO NEVER USED CONSISTENTLY A…
2018
Abstract Background Patients presenting to psychiatric services with their first episode of psychosis (FEP) report higher rates of previous cannabis use than the general population (Donoghue et al., 2011; Myles, Myles and Large, 2016). Evidence suggested that patients suffering from psychosis with a history of cannabis use have an earlier age of onset of psychosis (AOP) than those who never used it (Di Forti et al., 2013). We aim to investigate if the reported association between use of cannabis and AOP is consistent across different countries, once having taken into account different patterns of cannabis use (i.e. frequency of use and age at first use). Methods We analysed data on patterns…