4,084 research outputs found
Artificial Neural Network Symbol Estimator With Enhanced Robustness to Nonlinear Phase Noise
This letter reports a novel approach for nonlinear phase noise mitigation, based on artificial neural networks (ANNs) tailored to classification applications and a pre-processing stage of feature engineering. Starting with a set of proof-of-concept simulations, we verify that the proposed system can achieve optimal performance for the additive white Gaussian noise (AWGN) channel. Then, considering a dispersion-less channel with strong nonlinear phase noise (NLPN) distortion, we demonstrate a Q-factor increase of 0.4dB, comparing with standard carrier-phase estimation (CPE) followed by minimum distance detection. Finally, simulating the propagation of 64Gbaud PM-16QAM over standard single mode fiber (SSMF), we verify that the ANN-based solution is effective on wavelength-division multiplexing (WDM) transmission conditions, enabling to increase the maximum signal reach by approximately 1 fiber span over the legacy CPE-enabled NLPN compensation
Child with Choledochal Cyst Presenting with Episodes of Vomitting and Jaundice
A 2 year old girl presented to the emergency department with frequent episodes of vomiting and jaundice. Analytically, there was leucocytosis with normal neutrophil count, RCP of 5, 66 mg/dL and GGT 87 U/L. Colluria was also found
Screening for Autism Spectrum Disorders-Validation of the Portuguese Version of the Social Communication Questionnaire
There are no assessment and screening tools for Autism Spectrum Disorders (ASD) validated for the Portuguese population. The Social Communication Questionnaire (SCQ) is an useful screening tool of ASD diagnosis. The main objectives of our study were to produce a Portuguese version of the SCQ (SCQ-PF), study its internal consistency, sensitivity and specificity in order to evaluate its validity as a screening instrument for ASD. We also wanted to study the impact of intellectual disability and verbal impairment and other mental disorders on SCQ-PF psychometric properties. The study included 211 children and adolescents, aged 4-17, divided in three groups: ASD Group (n = 96), Other Mental Disorders Group (OMD) (n = 63) and No Mental Disorders (NMD) Group (n = 52). Parents or other primary caregiver provided information on the SCQ items. The SCQ-PF score was significantly higher in the ASD group than in the other groups (p < 0.001). As to internal consistency, Cronbach's alpha was 87%. ASD subjects were distinguished from subjects without ASD (OMD and NMD Groups) and the area under the curve (AUC) was 0.897 (95% Confidence Interval: 0.852-0.943), for a cutoff of 14, which yielded the highest AUC, with values of sensitivity and specificity 0.76 and 0.93, respectively. These findings show that SCQ- PF with a cutoff of 14 is an acceptable and useful screening tool for ASD in the Portuguese population
Analysis of the quality of hospital information systems Audit Trails.
BACKGROUND: Audit Trails (AT) are fundamental to information security in order to guarantee access traceability but can also be used to improve Health information System's (HIS) quality namely to assess how they are used or misused. This paper aims at analysing the existence and quality of AT, describing scenarios in hospitals and making some recommendations to improve the quality of information. METHODS: The responsibles of HIS for eight Portuguese hospitals were contacted in order to arrange an interview about the importance of AT and to collect audit trail data from their HIS. Five institutions agreed to participate in this study; four of them accepted to be interviewed, and four sent AT data. The interviews were performed in 2011 and audit trail data sent in 2011 and 2012. Each AT was evaluated and compared in relation to data quality standards, namely for completeness, comprehensibility, traceability among others. Only one of the AT had enough information for us to apply a consistency evaluation by modelling user behaviour. RESULTS: The interviewees in these hospitals only knew a few AT (average of 1 AT per hospital in an estimate of 21 existing HIS), although they all recognize some advantages of analysing AT. Four hospitals sent a total of 7 AT - 2 from Radiology Information System (RIS), 2 from Picture Archiving and Communication System (PACS), 3 from Patient Records. Three of the AT were understandable and three of the AT were complete. The AT from the patient records are better structured and more complete than the RIS/PACS. CONCLUSIONS: Existing AT do not have enough quality to guarantee traceability or be used in HIS improvement. Its quality reflects the importance given to them by the CIO of healthcare institutions. Existing standards (e.g. ASTM:E2147, ISO/TS 18308:2004, ISO/IEC 27001:2006) are still not broadly used in Portugal.publishersversionpublishe
Liver Transplantation Prevents Progressive Neurological Impairment in Argininemia
Argininemia is a rare hereditary disease due to a deficiency of hepatic arginase, which is the last enzyme of the urea cycle and hydrolyzes arginine to ornithine and urea.
The onset of the disease is usually in childhood, and clinical manifestations include progressive spastic paraparesis and
mental retardation. Liver involvement is less frequent and usually not as severe as observed in other UCDs. For this reason, and because usually there is a major neurological
disease at diagnosis, patients with argininemia are rarely considered as candidates for OLT despite its capacity to
replace the deficient enzyme by an active one. We report on long-term follow-up of two patients with argininemia.
Patient 1 was diagnosed by the age of 20 months and despite appropriate conventional treatment progressed to spastic paraparesis with marked limp. OLT was performed at
10 years of age with normalization of plasmatic arginine levels and guanidino compounds. Ten years post-OLT, under free diet, there is no progression of neurological
lesions. The second patient (previously reported by our group) was diagnosed at 2 months of age, during a neonatal cholestasis workup study. OLT was performed at the age of
7 years, due to liver cirrhosis with portal hypertension, in the absence of neurological lesions and an almost-normal brain MRI. After OLT, under free diet, there was normalization of plasmatic arginine levels and guanidino compounds. Twelve years post-OLT, she presents a normal neurological examination.
We conclude that OLT prevents progressive neurological impairment in argininemia and should be considered when appropriate conventional treatment fails
Data Mining Methods Applied to a Digital Forensics Task for Supervised Machine Learning
Digital forensics research includes several stages. Once we have collected the data the last goal is to obtain a model in order to predict the output with unseen data. We focus on supervised machine learning techniques. This chapter performs an experimental study on a forensics data task for multi-class classification including several types of methods such as decision trees, bayes classifiers, based on rules, artificial neural networks and based on nearest neighbors. The classifiers have been evaluated with two performance measures: accuracy and Cohen’s kappa. The followed experimental design has been a 4-fold cross validation with thirty repetitions for non-deterministic algorithms in order to obtain reliable results, averaging the results from 120 runs. A statistical analysis has been conducted in order to compare each pair of algorithms by means of t-tests using both the accuracy and Cohen’s kappa metrics
Efficacy of diadynamic currents as an adjunct to exercise to manage symptoms of knee osteoarthritis in adults: A randomized controlled clinical trial
Objective
To investigate the effect of diadynamic currents administered prior to exercises on pain and disability in patients with osteoarthritis of the knee.
Design
A randomized-controlled trial.
Setting
Special Rehabilitation Services in Taboão da Serra.
Participants
Patients with bilateral knee osteoarthritis.
Intervention
Participants were randomly allocated to Group I (diadynamic currents and exercises; n = 30, 60 knees) or Group II (exercises alone; n = 30, 60 knees) and were treated three times a week for 8 weeks.
Main outcome measures
The primary outcome measures were change in knee pain evaluated by visual analog scale and disability Index Score (Lequesne). Secondary outcomes included change in mobility (Timed Up and Go test), range of motion (goniometer), muscle strength (dynamometer), a composite score for pain and disability (Western Ontario and McMaster Universities Osteoarthritis questionnaire), and a drug diary to measure consumption of rescue pain medication (paracetamol). All measurements were collected at baseline, 8 weeks, and 6 months from baseline (follow-up).
Results
There were 60 participants with a mean (SD) age of 63.40 (8.20) years. Between-group differences in the follow-up (8 weeks and 6 months) were observed for pain at rest, pain during activities of daily living and disability. There was improvement in Group I that was maintained for the three variables 6 months after treatment. Mean difference for pain at rest was −3.08 points (95% confidence interval −4.13; −2.02), p < 0.01 with an effect size of 1.4; mean difference for pain during activities of daily living was −2.40 points (95% confidence interval −3.34; −1.45), p < 0.01 with an effect size of 1.24; and mean difference for disability was −4.08 points (95% confidence interval −5.89; −2.26), p < 0.01 with an effect size of 1.04.
Conclusion
Patients with symptomatic knee osteoarthritis receiving 8 weeks of treatment with diadynamic currents as an adjunct to a program of exercises had significantly greater improvements in pain and disability than those receiving exercises alone. Beneficial effects were sustained for 6 months
Targeting BTK for the treatment of FLT3-ITD mutated acute myeloid leukemia
Approximately 20% of patients with acute myeloid leukaemia (AML) have a mutation in FMS-like-tyrosine-kinase-3 (FLT3). FLT3 is a trans-membrane receptor with a tyrosine kinase domain which, when activated, initiates a cascade of phosphorylated proteins including the SRC family of kinases. Recently our group and others have shown that pharmacologic inhibition and genetic knockdown of Bruton's tyrosine kinase (BTK) blocks AML blast proliferation, leukaemic cell adhesion to bone marrow stromal cells as well as migration of AML blasts. The anti-proliferative effects of BTK inhibition in human AML are mediated via inhibition of downstream NF-κB pro-survival signalling however the upstream drivers of BTK activation in human AML have yet to be fully characterised. Here we place the FLT3-ITD upstream of BTK in AML and show that the BTK inhibitor ibrutinib inhibits the survival and proliferation of FLT3-ITD primary AML blasts and AML cell lines. Furthermore ibrutinib inhibits the activation of downstream kinases including MAPK, AKT and STAT5. In addition we show that BTK RNAi inhibits proliferation of FLT3-ITD AML cells. Finally we report that ibrutinib reverses the cyto-protective role of BMSC on FLT3-ITD AML survival. These results argue for the evaluation of ibrutinib in patients with FLT3-ITD mutated AML
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