298 research outputs found

    The institutional fate of Uexküll’s umwelt theory at the University of Hamburg

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    Due to Jakob von Uexküll’s umwelt theory, the Institute for Umwelt Research at the University of Hamburg, that was founded in 1928, was a unique institution worldwide for holistic research into animal behaviour and perception. However, Uexküll’s vitalistic-teleological approach and his uncompromising anti- Darwinian stance increasingly isolated him. When the closure of his institute was imminent as part of his statutory retirement in 1935, Uexküll ingratiated himself with the National Socialists in a letter to the Reich Minister for Science, Education, and Culture, which serves as a starting point for the article’s detailed discussion of his relationship to National Socialism. Since umwelt theory could be used for the training of guide dogs and other animals useful for military purposes, the institute survived. Still, finding a suitable successor to Uexküll proved difficult because hardly anyone among the German zoologists believed Friedrich Brock, Uexküll’s preferred candidate, would live up to Uexküll’s originality. The most important opponent to Brock’s appointment was Berthold Klatt, professor of zoology at the University of Hamburg, who did not expect any significant progress in zoology from Uexküll’s umwelt theory. After Brock’s death in 1958, the sworn circle of supporters of Uexküll’s umwelt theory tried in vain to push through a successor from their ranks. At the instigation of Curt Kosswig, Klatt’s successor in the Chair of Zoology, Franz Sauer succeeded Brock in 1959. However, a polemical article written by Gösta von Uexküll provoked a scandal, in the wake of which Sauer resigned. In 1960 the Institute for Umwelt Research became a department of the Zoological Institute, existing in the lecture timetables until 1966. Thus, the fate of Uexküll’s research institution depended mainly on external and personal factors or, to speak in Uexküllian terms, on the umwelten of the protagonists and antagonists

    Albertino Rinaldi da Salso on the Motion of Elements and Mixed Bodies in a Void

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    In his questio on the motion of elements and mixed bodies in a void the Italian professor of practical medicine, Albertino Rinaldi da Salso di Piacenza (Albertinus de Rainaldis de Placentia, also known as Albertino da Piacenza), held the clearly non-Aristotelian view that an element in a void would not move instantaneously, but successively. To prove his conclusion Albertino draws to a large degree on arguments proposed by Richard Kilvington. Among the few 14th century authors who rejected Aristotle’s account of motion in a vacuum Kilvington had presented the most thorough analysis of this subject. While Kilvington is known for his sophisticated argumentation and entangled style of presenting and sometimes nearly hiding his own opinions, Albertino’s treatise is better structured, and his conclusions are brought out more clearly. His disputation is an impressive testimony to the impact of Kilvington’s views of motion in a void

    Comparing adaptive coding of reward in bipolar I disorder and schizophrenia

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    Deficits in neural processing of reward have been described in both bipolar disorder (BD) and schizophrenia (SZ), but it remains unclear to what extent these deficits are caused by similar mechanisms. Efficient reward processing relies on adaptive coding which allows representing large input spans by limited neuronal encoding ranges. Deficits in adaptive coding of reward have previously been observed across the SZ spectrum and correlated with total symptom severity. In the present work, we sought to establish whether adaptive coding is similarly affected in patients with BD. Twenty-five patients with BD, 27 patients with SZ and 25 healthy controls performed a variant of the Monetary Incentive Delay task during functional magnetic resonance imaging in two reward range conditions. Adaptive coding was impaired in the posterior part of the right caudate in BD and SZ (trend level). In contrast, BD did not show impaired adaptive coding in the anterior caudate and right precentral gyrus/insula, where SZ showed deficits compared to healthy controls. BD patients show adaptive coding deficits that are similar to those observed in SZ in the right posterior caudate. Adaptive coding in BD appeared more preserved as compared to SZ participants especially in the more anterior part of the right caudate and to a lesser extent also in the right precentral gyrus. Thus, dysfunctional adaptive coding could constitute a fundamental deficit in severe mental illnesses that extends beyond the SZ spectrum

    Numerical approximation of table functions on the basis of multidimensional optimization methods for modeling physics and technics problems

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    The aim of the article is to present an approximation method based on multidimensional optimization methods which does not require preliminary information about the derivatives of the approximating function. It is proposed to use a combination of the grid method, coordinate descent method and the golden section method to solve the task of optimizing the objective function (standard deviation in the nodes of the tabular function). The considered example of the approximation of the flight trajectory of a body in the atmosphere illustrates the comparability of the results of the proposed method and the least squares method

    Cerebellar and cortico-striatal-midbrain contributions to reward-cognition processes and apathy within the psychosis continuum

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    Negative symptoms in the psychosis continuum are linked to impairments in reward processing and cognitive function. Processes at the interface of reward processing and cognition and their relation to negative symptoms remain little studied, despite evidence suggestive of integration in mechanisms and neural circuitry. Here, we investigated brain activation during reward-dependent modulation of working memory (WM) and their relationship to negative symptoms in subclinical and early stages of the psychosis continuum. We included 27 persons with high schizotypal personality traits and 23 patients with first episode psychosis as well as 27 healthy controls. Participants underwent functional magnetic resonance imaging while performing an established 2-back WM task with two reward levels (5 CHF vs. no reward), which allowed us to assess common reward-cognition regions through whole-brain conjunction analyses and to investigate relations with clinical scores of negative symptoms. As expected for behavior, reward facilitated performance while cognitive load diminished it. At the neural level, the conjunction of high reward and high cognitive load contrasts across the psychosis continuum showed increased hemodynamic activity in the thalamus and the cerebellar vermis. During high cognitive load, more severe apathy but not diminished expression in the psychosis continuum was associated with reduced activity in right lateral orbitofrontal cortex, midbrain, posterior vermal cerebellum, caudate and lateral parietal cortex. Our results suggest that hypoactivity in the cerebellar vermis and the cortical-striatal-midbrain-circuitry in the psychosis continuum relates to apathy possibly via impaired flexible cognitive resource allocation for effective goal pursuit

    Negative symptoms in alcohol use disorder: A pilot study applying the two-factor model of negative symptoms to patients with alcohol use disorder

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    Background and aimsAlcohol Use Disorder (AUD) is characterized by a reduction in goal-directed behavior, with alcohol use taking precedence over other areas of life. These features in AUD resemble negative symptoms in schizophrenia, especially the reduction in motivation and pleasure (MAP). Given the clinical similarities of negative symptoms across diagnostic categories, it comes as a surprise that there are few investigations on negative symptoms in alcohol and other substance use disorders. To our knowledge, our study is the first to assess negative symptoms in AUD based on a two-factorial approach, and to investigate the interrelation of these dimensions with the severity of AUD, and alcohol craving.Materials and methodsWe examined a sample of 42 patients with AUD at the Psychiatric University Hospital in Zurich. Participants provided self-report and interview-based measures of the severity of AUD, negative symptoms, and alcohol craving. Finally, we used data from the electronic health records of the patients.ResultsPatients with AUD show negative symptoms to a similar extent as patients with schizophrenia or bipolar disorder. We found a positive correlation between the extent of impairment within the MAP factor and overall severity of AUD. Furthermore, MAP negative symptoms were correlated with alcohol craving. In a linear regression, negative symptoms predicted alcohol craving whereas depression did not.SummaryNegative symptoms as conceptualized for schizophrenia are prevalent in patients with AUD and associated with the severity of AUD. More specifically, severity of AUD correlates with diminished motivation and pleasure, highlighting the importance of disturbances in motivational functions in AUD. This is further supported by the correlation between negative symptoms and craving, a hallmark of AUD. Taken together, our findings suggest that negative symptoms might be a highly relevant but hitherto often neglected therapeutic target in AUD

    Use of Long-Acting Injectable Antipsychotics in Inpatients with Schizophrenia Spectrum Disorder in an Academic Psychiatric Hospital in Switzerland

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    Long-acting injectable antipsychotics (LAIs) offer many benefits to patients with schizophrenia spectrum disorder (SSD). They are used with very different frequencies due to questions of eligibility or patients and prescribers’ attitudes towards LAI use. We assessed the prescribing rates of LAIs in a large academic psychiatric hospital with a public service mandate in Switzerland and compared them with other countries and health care systems. To our knowledge, this study is the first to investigate inpatient LAI use in Europe. Medical records of all patients diagnosed with SSD discharged from the Clinic of Adult Psychiatry of the University Hospital of Psychiatry Zurich over a 12 month period from January to December 2019 were evaluated regarding the prescribed antipsychotics at the time of discharge. The rates of use of LAIs among all patients and among patients receiving LAI-eligible antipsychotic substances were assessed retrospectively. We assessed records of 885 patients with SSD. Among all cases, 13.9% received an LAI. Among patients who received antipsychotic medication that was eligible for LAI use (n = 434), 28.1% received an agent as an LAI. LAI use included paliperidone palmitate (69.9%), aripiprazole monohydrate (14.6%), risperidone (4.9%) and first-generation LAIs (9.8%). Compared to international frequencies of LAI administration, the prescription rate of LAIs in SSD patients was low. Further studies will evaluate patient- and prescriber-related reasons for this low rate

    Apathy But Not Diminished Expression in Schizophrenia Is Associated With Discounting of Monetary Rewards by Physical Effort

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    Negative symptoms in schizophrenia have been grouped into the 2 factors of apathy and diminished expression, which might be caused by separable pathophysiological mechanisms. Recently, it has been proposed that apathy could be due to dysfunctional integration of reward and effort during decision making. We asked whether apathy in particular is associated with stronger devaluation ("discounting”) of monetary rewards that require physical effort. Thirty-one patients with schizophrenia and 20 healthy control participants performed a computerized effort discounting task in which they could choose to exert physical effort on a handgrip to obtain monetary rewards. This procedure yields an individual measure for the strength of effort discounting. The degree of effort discounting was strongly correlated with apathy, but not with diminished expression. Importantly, the association between apathy and effort discounting was not driven by cognitive ability, antipsychotic medication, or other clinical and demographic variables. This study provides the first evidence for a highly specific association of apathy with effort-based decision making in patients with schizophrenia. Within a translational framework, the present effort discounting task could provide a bridge between apathy as a psychopathological phenomenon and established behavioral tasks to address similar states in animal
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