Reduced reward-related probability learning in schizophrenia patients

Although it is known that individuals with schizophrenia demonstrate marked impairment in reinforcement learning, the details of this impairment are not known. The aim of this study was to test the hypothesis that reward-related probability learning is altered in schizophrenia patients. Twenty-five clinically stable schizophrenia patients and 25 age- and gender-matched controls participated in the study. A simple gambling paradigm was used in which five different cues were associated with different reward probabilities (50%, 67%, and 100%). Participants were asked to make their best guess about the reward probability of each cue. Compared with controls, patients had significant impairment in learning contingencies on the basis of reward-related feedback. The correlation analyses revealed that the impairment of patients partially correlated with the severity of negative symptoms as measured on the Positive and Negative Syndrome Scale but that it was not related to antipsychotic dose. In conclusion, the present study showed that the schizophrenia patients had impaired reward-based learning and that this was independent from their medication status

Lumbar opening pressure and radiologic scoring in idiopathic intracranial hypertension : is there any correlation?

Background: To investigate correlation between lumbar opening pressure (LOP) and radiological scores based on cranial MRI and contrast-enhanced MR venography in patients with idiopathic intracranial hypertension (IIH). Material/Methods: Patients with IIH who underwent brain MRI and contrast-enhanced MR venography before measurement of LOP between 2010-2014 were evaluated retrospectively. Three experienced radiologists (blinded to LOP values) evaluated a total of 51 patients. They reached a consensus on the presence or absence of 6 radiological findings identified in the literature as characteristic for IIH: empty sella, perioptic dilation, optical tortuosity, flattening of the posterior globe, swelling of the optic disc, and bilateral transverse sinus stenosis. The radiological score was obtained by giving 1 point for the presence of each finding, with the highest possible score of 6 points. The correlation between the calculated radiological scores and LOP was evaluated. Results: There was no significant correlation between LOP and radiological scores (r=0.095; p=0.525, Spearman's rank coefficient). Similarly, no significant correlation was detected between LOP and each of the radiological findings (partial empty sella [p=0.137], perioptic dilation [p=0.265], optical tortuosity [p=0.948], flattening of the posterior globe [p=0.491], swelling of the optic disc [p=0.881], and bilateral dural sinus stenosis [p=0.837], Mann-Whitney U test). Conclusions: There was no significant correlation between LOP and reliable radiological features of IIH

The genetic history of the Southern Arc: a bridge between West Asia and Europe

By sequencing 727 ancient individuals from the Southern Arc (Anatolia and its neighbors in Southeastern Europe and West Asia) over 10,000 years, we contextualize its Chalcolithic period and Bronze Age (about 5000 to 1000 BCE), when extensive gene flow entangled it with the Eurasian steppe. Two streams of migration transmitted Caucasus and Anatolian/Levantine ancestry northward, and the Yamnaya pastoralists, formed on the steppe, then spread southward into the Balkans and across the Caucasus into Armenia, where they left numerous patrilineal descendants. Anatolia was transformed by intra–West Asian gene flow, with negligible impact of the later Yamnaya migrations. This contrasts with all other regions where Indo-European languages were spoken, suggesting that the homeland of the Indo-Anatolian language family was in West Asia, with only secondary dispersals of non-Anatolian Indo-Europeans from the steppe

Türkiye'deki Büyük Depremlerin IMKB'de Sektörel Etkisinin Test Edilmesi

The purpose of this study is to detect the effects of earthquakes on financial markets within the scope of Efficient Market Hypothesis. In this context, 2011 Van, 1999 Marmara and 1998 Ceyhan earthquakes effects on trading securities of insurance, banking, construction and real estate investment companies quoted in Istanbul Stock Exchange (ISE) are analyzed by event study method and significance of abnormal and cumulative abnormal returns are detected both with parametric and nonparametric (rank) tests.Bu çalışmanın amacı, depremlerin finansal piyasalara etkilerini Etkin Piyasalar Hipotezi kapsamında incelemektir. Bu çerçevede, 2011 Van, 1999 Marmara ve 1998 Ceyhan depremlerinin İstanbul Menkul Kıymetler Borsasında (İMKB) işlem gören sigortacılık, bankacılık, taş-toprak ve gayrimenkul yatırım ortaklığı firmalarının hisse senetleri getirileri üzerinde etkisi olay çalışması ile analiz edilmiş ve çalışma sonucu hesaplanan anormal getiriler ile kümülatif anormal getirilerin anlamlılıkları parametrik ve parametrik olmayan (rank testi) testler yardımıyla tespit edilmiştir

A temporal neuro-fuzzy approach for time-series analysis

In this paper, a temporal neuro-fuzzy system is presented which provides an environment that keeps temporal rela tionships between input and output variables. The sys tem is used to forecast the future behavior of time series data. It is based on ANFIS neuro-fuzzy system and named ANFIS unfolded in time. The rule base contains tempo ral TSK(Takagi-Sugeno-Kang) fuzzy rules. In the training phase, a modified back-propagation learning algorithm is used. The model is tested on Gas-furnace data which is a benchmark problem