Forecasting time series by means of evolutionary algorithms

Proceeding of: 8th International Conference in Parallel Problem Solving from Nature - PPSN VIII , Birmingham, UK, September 18-22, 2004.The time series forecast is a very complex problem, consisting in predicting the behaviour of a data series with only the information of the previous sequence. There is many physical and artificial phenomenon that can be described by time series. The prediction of such phenomenon could be very complex. For instance, in the case of tide forecast, unusually high tides, or sea surges, result from a combination of chaotic climatic elements in conjunction with the more normal, periodic, tidal systems associated with a particular area. Too much variables influence the behaviour of the water level. Our problem is not only to find prediction rules, we also need to discard the noise and select the representative data. Our objective is to generate a set of prediction rules. There are many methods tying to achieve good predictions. In most of the cases this methods look for general rules that are able to predict the whole series. The problem is that usually the time series has local behaviours that dont allow a good level of prediction when using general rules. In this work we present a method for finding local rules able to predict only some zones of the series but achieving better level prediction. This method is based on the evolution of set of rules genetically codified, and following the Michigan approach. For evaluating the proposal, two different domains have been used: an artificial domain widely use in the bibliography (Mackey-Glass series) and a time series corresponding to a natural phenomenon, the water level in Venice Lagoon.Investigation supported by the Spanish Ministry of Science and Technology through the TRACER project under contract TIC2002-04498-C05-

Treatment course comparison between anxiety-related disorders in adult outpatients: a Leiden routine outcome monitoring study

Anxiety-related disorders constitute the leading prevalent mental disorders, with major burden on patients, their relatives, and society. Moreover, there is considerable treatment nonadherence/nonresponse. We used routine outcome monitoring (ROM) data from outpatients covering four anxiety-related disorders (DSM-IV-R, N = 470) to examine their 6-month treatment course and its predictors: generalized anxiety disorder, panic disorder with agoraphobia, obsessive-compulsive disorder, and posttraumatic stress disorder. Measures included Mini-International Neuropsychiatric Interview Plus, Brief Symptom Inventory (BSI), Montgomery-Åsberg Depression Rating Scale (MADRS), Brief Anxiety Scale (BAS), and Short Form Health Survey 36 (SF-36). On the clinician-rated instruments (MADRS/BAS), all anxiety-related disorder groups showed a significant albeit modest improvement after treatment. On the BSI self-rating, only generalized anxiety disorder and posttraumatic stress disorder showed a significant modest improvement. No anxiety-related disorder groups improved significantly regarding SF-36 physical functioning. For BSI symptom course, significant predictors were comorbid somatoform/total disorders, SF-36 physical functioning/general health, and MADRS score. Clinical implications and future research recommendations are discussed. Stress-related psychiatric disorders across the life spa

Measurement and interpretation of skin prick test results

Background: There are several methods to read skin prick test results in type-I allergy testing. A commonly used method is to characterize the wheal size by its 'average diameter'. A more accurate method is to scan the area of the wheal to calculate the actual size. In both methods, skin prick test (SPT) results can be corrected for histamine-sensitivity of the skin by dividing the results of the allergic reaction by the histamine control. The objectives of this study are to compare different techniques of quantifying SPT results, to determine a cut-off value for a positive SPT for histamine equivalent prick -index (HEP) area, and to study the accuracy of predicting cashew nut reactions in double-blind placebo-controlled food challenge (DBPCFC) tests with the different SPT methods. Methods: Data of 172 children with cashew nut sensitisation were used for the analysis. All patients underwent a DBPCFC with cashew nut. Per patient, the average diameter and scanned area of the wheal size were recorded. In addition, the same data for the histamine-induced wheal were collected for each patient. The accuracy in predicting the outcome of the DBPCFC using four different SPT readings (i.e. average diameter, area, HEP-index diameter, HEP-index area) were compared in a Receiver-Operating Characteristic (ROC) plot. Results: Characterizing the wheal size by the average diameter method is inaccurate compared to scanning method. A wheal average diameter of 3 mm is generally considered as a positive SPT cut-off value and an equivalent HEP-index area cut-off value of 0.4 was calculated. The four SPT methods yielded a comparable area under the curve (AUC) of 0.84, 0.85, 0.83 and 0.83, respectively. The four methods showed comparable accuracy in predicting cashew nut reactions in a DBPCFC. Conclusions: The 'scanned area method' is theoretically more accurate in determining the wheal area than the 'average diameter method' and is recommended in academic research. A HEP-index area of 0.4 is determined as cut-off value for a positive SPT. However, in clinical practice, the 'average diameter method' is also useful, because this method provides similar accuracy in predicting cashew nut allergic reactions in the DBPCFC

Attentional Biases and Their Association with Substance-Use-Related Problems and Addictive Behaviors: The Utility of a Gamified Value-Modulated Attentional Capture Task

BackgroundAttentional biases towards reward stimuli have been implicated in substance use-related problems. The value-modulated attentional capture (VMAC) task assesses such reward-related biases. The VMAC task widely used in lab studies tends to be monotonous and susceptible to low effort. We therefore tested a gamified online version of the VMAC that aimed to increase participant engagement. Our goal was to examine how VMAC is associated with substance use-related problems and addictive behaviors, and whether this association is moderated by cognitive control.MethodsWe recruited 285 participants from an online community, including heavy alcohol users. All participants completed a novel gamified version of the VMAC task, measures of substance use and addictive behaviors (addictive-like eating behavior, problematic smartphone use), the WebExec measure of problems with executive functions, and the Stroop Adaptive Deadline Task (SDL) as a measure of cognitive control.ResultsThe gamified VMAC task successfully identified value-modulated attentional capture effects towards high-reward stimuli. We found no significant associations between VMAC scores, problematic alcohol or cannabis use, addictive behaviors, or any moderation by a behavioral measure of cognitive control. Exploratory analyses revealed that self-reported cognitive problems were associated with more alcohol-, and cannabis-related problems, and addictive behaviors. Greater attentional capture (VMAC) was associated with more cannabis use-related problems among individuals with higher levels of self-reported cognitive problems.ConclusionsOur study is one of the first to demonstrate the utility of the gamified version of the VMAC task in capturing attentional reward biases. Self-reported problems with cognitive functions represent a key dimension associated with substance use-related problems and addictive behaviors

Presence of celiac disease epitopes in modern and old hexaploid wheat varieties: wheat breeding may have contributed to increased prevalence of celiac disease

Gluten proteins from wheat can induce celiac disease (CD) in genetically susceptible individuals. Specific gluten peptides can be presented by antigen presenting cells to gluten-sensitive T-cell lymphocytes leading to CD. During the last decades, a significant increase has been observed in the prevalence of CD. This may partly be attributed to an increase in awareness and to improved diagnostic techniques, but increased wheat and gluten consumption is also considered a major cause. To analyze whether wheat breeding contributed to the increase of the prevalence of CD, we have compared the genetic diversity of gluten proteins for the presence of two CD epitopes (Glia-α9 and Glia-α20) in 36 modern European wheat varieties and in 50 landraces representing the wheat varieties grown up to around a century ago. Glia-α9 is a major (immunodominant) epitope that is recognized by the majority of CD patients. The minor Glia-α20 was included as a technical reference. Overall, the presence of the Glia-α9 epitope was higher in the modern varieties, whereas the presence of the Glia-α20 epitope was lower, as compared to the landraces. This suggests that modern wheat breeding practices may have led to an increased exposure to CD epitopes. On the other hand, some modern varieties and landraces have been identified that have relatively low contents of both epitopes. Such selected lines may serve as a start to breed wheat for the introduction of 'low CD toxic' as a new breeding trait. Large-scale culture and consumption of such varieties would considerably aid in decreasing the prevalence of CD

Kiyang-yang, a West-African Postwar Idiom of Distress

In 1984, a healing cult for young barren women in southern Guinea Bissau developed into a movement, Kiyang-yang, that shook society to its foundations and had national repercussions. “Idiom of distress” is used here as a heuristic tool to understand how Kiyang-yang was able to link war and post-war-related traumatic stress and suffering on both individual and group levels. An individual experience born from a traumatic origin may be generalized into an idiom that diverse sectors of society could embrace for a range of related reasons. We argue that, for an idiom to be understood and appropriated by others, there has to be resonance at the level of symbolic language and shared experiences as well as at the level of the culturally mediated contingent emotions it communicates. We also argue that through its symbolic references to structural causes of suffering, an idiom of distress entails a danger for those in power. It can continue to exist only if its etiology is not exposed or the social suffering it articulates is not eliminated. We finally argue that idioms of distress are not to be understood as discrete diagnostic categories or as monodimensional expressions of “trauma” that can be addressed

Persistence of frequently transmitted drug-resistant HIV-1 variants can be explained by high viral replication capacity

Background: In approximately 10% of newly diagnosed individuals in Europe, HIV-1 variants harboring transmitted drug resistance mutations (TDRM) are detected. For some TDRM it has been shown that they revert to wild type while other mutations persist in the absence of therapy. To understand the mechanisms explaining persistence we investigated the in vivo evolution of frequently transmitted HIV-1 variants and their impact on in vitro replicative capacity. Results: We selected 31 individuals infected with HIV-1 harboring frequently observed TDRM such as M41L or K103N in reverse transcriptase (RT) or M46L in protease. In all these samples, polymorphisms at non-TDRM positions were present at baseline (median protease: 5, RT: 6). Extensive analysis of viral evolution of protease and RT demonstrated that the majority of TDRM (51/55) persisted for at least a year and even up to eight years in the plasma. D

Exploring food insecurity and obesity in Dutch disadvantaged neighborhoods: a cross-sectional mediation analysis

Background: Food insecurity is related to risk of adverse health outcomes such as obesity, but the explanatory factors underlying this association are still unclear. This study aimed to assess the association between food insecurity and obesity, and to explore potential mediation by sociodemographic and lifestyle factors. Methods: This cross-sectional study was conducted among 250 participants in a deprived urban area in the Netherlands. Data on sociodemographic and lifestyle factors, food insecurity status and diet quality were collected using questionnaires. Diet quality was determined based on current national dietary guidelines. BMI was calculated from self-reported height and weight. Regression analyses were performed to explore the association between food insecurity and BMI status. Mediation analyses were performed to estimate the total-, direct-, and indirect effect and proportion of total effect mediated of the food insecurity-obesity association. Results: The overall prevalence of food insecurity was 26%. Food insecurity was associated with obesity (OR = 2.49, 95%CI = 1.16, 5.33), but not with overweight (OR = 1.15, 95%CI = 0.54, 2.45) in the unadjusted model. The food insecurity-obesity association was partially mediated by living situation (proportion mediated: 15.4%), diet quality (− 18.6%), and smoking status (− 15.8%) after adjustment for other covariates. Conclusions: The findings of this study suggest an association between food insecurity and obesity. Living situation, diet quality and smoking status explained part, but not all, of the total association between food insecurity and obesity. Future longitudinal studies are warranted to examine the temporal order of the food insecurity-obesity association and potential mediators in this relationship. In addition, food insecurity and its potential consequences need to be taken into account in obesity prevention programs and policies

Tetralogy of Fallot in the Current Era

Only few studies have reported long-term outcome of the transatrial-transpulmonary approach in the current era of management of tetralogy of Fallot (ToF). We investigated 15-year outcome of correction via a transatrial-transpulmonary approach in a large cohort of successive patients operated in the 21st century. All infant ToF patients undergoing transatrial-transpulmonary ToF correction between 2000 and 2015 were included (N = 177, 106 male, median follow-up 7.1 (interquartile range 3.0–10.9) years. Data regarding postoperative complications, reinterventions, development of atrial and ventricular arrhythmia, cardiac function, and survival were evaluated. Prior shunting was performed in 10 patients (6%). The transatrial-transpulmonary approach resulted in valve-sparing surgery in 57 patients (32%). Postoperative surgical complications included junctional ectopic tachycardia (N = 12, 7%), pericardial (N = 10, 6%) or pleural effusion (N = 7, 3%), chylothorax (N = 7, 4%), bleeding requiring reoperation (N = 4, 3%), and superficial wound infection (N = 1). Fifty-one patients underwent 68 reinterventions, mainly due to pulmonary restenosis (PS) (N = 57). ToF correction at age <2 months and double outlet or double-chambered right ventricle variants of the ToF spectrum were independent predictors for reintervention. Patients undergoing valve-sparing ToF correction had a significant longer PR-free survival than those with a transannular patch (8.5 [95% confidence interval 6.8–10.3] years vs 1.1 [95% confidence interval 0.8–1.5] years; P < 0.001). Overall mortality was 2.8%; mortality rates were higher in premature/dysmature newborns (0.7% vs 9.5%; P < 0.001). Although the 15-year outcome of the transatrial-transpulmonary approach in terms of postoperative complications and mortality rates is excellent, the high incidence of moderate and severe PR is worrisome. Valve-sparing surgery was associated with a substantially lower incidence of PR, yet was surgically not possible in the majority of patients