Cannabis and other variables affecting age at onset in a schizophrenia founder population

Objective: An ongoing collaborative study between the Human Neurogenetic Laboratory of Rockefeller University, New York and the Department of Psychiatry at the University of Pretoria, has been taking place since 1997, to map genes for schizophrenia. Aspects of cannabis use/abuse will be reported.Method: The Diagnostic Interview for Genetic Studies [DIGS] is used for all diagnosis. A narrative report is completed. From this database we determined: gender, diagnostic subtype, age of illness onset, early insults, early deviant behaviour, cannabis use/abuse and family history of schizophrenia.Results: From 341 subjects we found: 61% [n=209] males and 39% [n=132] females. In males, 75% [n=156] had schizophrenia and 25% [n=53] schizoaffective disorder[SADJ]. In females 74% [n=97] had schizophrenia and 26% [n=35] SAD. 35% of subjects, [n=118], 44% [n=91] males and 20% [n=27] female's used/abused cannabis. The mean age at onset of illness for the males was 20.5 years. This is significantly earlier than that of males with no cannabis use/abuse group as well as for both these groups in females. The long-term course of illness was similar in both cannabis use/abuse and non-use/abuse groups. An analysis of variance was used to determine the contribution of different factors in determining the age of criteria onset. According to the results obtained, early deviant behaviour was the most important determining age of criteria onset. The group with the lowest mean age of criteria were male users of cannabis with severe early deviant behaviour [18,4 years]. Conclusion: Cannabis use/abuse is common amongst male schizophrenia subjects, and affects age at onset of illness. Early deviant behaviour in the first ten years of life in these subjects is more important in this regard, and may be seen as a possible endophenotypical marker. Keywords: cannabis, psychosis, schizophrenia, founder population South African Psychiatry Review Vol. 9(2) 2006: 99-10

Electricity load forecasting with artificial neural networks

Artificial neural networks are powerful tools for time series forecasting. The problem addressed in this article is to do multi-step prediction of a stationary time series, and to find the associated prediction limits. Artificial neural network models for time series are non-linear. However, results that are applicable to linear models are sometimes mistakenly applied to non-linear models. One example where this is observed is in multi-step forecasting. A bootstrap method is proposed to calculate one- and multi-step predictions and prediction limits. The results are applied to an electricity load time series as well as to a pure autoregressive time series.Kunsmatige neurale netwerke is kragtige instrumente vir tydreeksvoorspelling. In hierdie artikel word multistap-vooruitberaming van ‘n stasionêre tydreeks en die gepaardgaande vertroueinterval behandel. Resultate wat slegs geldig is vir lineêre modelle word soms verkeerdelik op neurale netwerkmodelle toegepas. ‘n Voorbeeld hiervan kom in multistap-voorspelling voor. ‘n Skoenlusmetode, word voorgestel waarvolgens eenstap- en multistap- voorspellings en vertroueintervalle bereken kan word. Die resultate word op ‘n elektrisiteitslastydreeks en op ‘n suiwer outoregressiewe tydreeks toegepas.http://sajie.journals.ac.z

Distribution-free approach to the evaluation of reliability of complex systems

In the industrial community it is well known that the failure rate of the manufactured units vary with time due to a variety of causes, namely, engineering design, manufacturing process, maintenance and quality inspection procedures and various assignable and non-assignable factors. Such failure rates invariably exhibit changes in both level and slope and at times exhibit periodic patterns as well. Therefore it would be quite inappropriate and erroneous to analyze such stochastic series of observations using the usual failure distribution approach. Since such data can be construed as time series, we suggest in this paper the time series techniques including the Kalman filter for their analysis. Other advantages of using the latter techniques are that the periodicities, if any, can be taken into account and short-term forecasts can be made which otherwise would not have been possible

Ultrasound study of the asymptomatic shoulder in patients with a confirmed symptomatic rotator cuff tear in the opposite shoulder

OBJECTIVE: To document the incidence of asymptomatic rotator cuff tears in patients with a confirmed symptomatic tear in the opposite shoulder, and to identify ultrasound findings that may distinguish symptomatic from asymptomatic tears. DESIGN: When patients are referred for an ultrasound examination for the confirmation of symptomatic rotator cuff tear the opposite shoulder is often used for comparison. However, patients often have a similar tear on the asymptomatic side. Fifty patients with a confirmed symptomatic rotator cuff tear and an asymptomatic shoulder on the opposite side were chosen for inclusion. The patients were examined using a Siemens Sonoline Elegra 7.5 MHz linear multi-frequency probe. The appearance of the rotator cuff, long head of the biceps and the subacromial-subdeltoid bursa (SASD bursa) were documented. The antero-posterior (AP) dimension of the supraspinatus muscle and fat between the trapezius and supraspinatus muscles were measured, which indicated if a tear was acute or chronic. The width and length of the rotator cuff tear were measured. SETTING: Division of Sports Medicine, University of Pretoria. RESULTS: Fifty-four per cent of the asymptomatic shoulders had tears. We found that the symptomatic tears were larger, appeared more chronic and had an associated biceps tendinopathy and glenohumeral joint effusion

Prevalensie van seisoenale gemoedsversteuring in psigiatriese pasiënte met major depressie of bipolêre versteuring

Dit word reeds eeue lank aanvaar dat die seisoene 'n invloed op die mens se gemoed het, maar navorsing is eers die afgelope dekade daaroor gedoen. Navorsers uit die Noordelike halfrond het bevind dat depressiewe versteurings dikwels in die herfs of winter begin en in die lente eindig. In die lente gaan dit soms oor in 'n hipomaniese episode

Dealing with the Past: Memory and European Integration

Memory has become an object of dispute in the EU. Different groups and states do not have a full convergence of views and this raises the question as to whether the EU should or should not be involved. A pluralist conception of justice would argue that the recognition of memory is not excluded as a form of justice. Adopting this view, this paper argues that the recognition of memory can be addressed at the EU level if the different components of justice are allocated to the proper spheres (recognition, retribution and recognition) and levels (national and European).This paper was written thanks to a grant from the Spanish Ministry of Education (Grant PR2010-0077) under the Programm for stances of senior professors and researchers in foreign research institutions.Peer reviewe