Model-Based and Model-Free Decisions in Alcohol Dependence

This publication is with permission of the rights owner freely accessible due to an alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Background: Human and animal work suggests a shift from goal-directed to habitual decision-making in addiction. However, the evidence for this in human alcohol dependence is as yet inconclusive. Methods: Twenty-six healthy controls and 26 recently detoxified alcohol-dependent patients underwent behavioral testing with a 2-step task designed to disentangle goal-directed and habitual response patterns. Results: Alcohol-dependent patients showed less evidence of goal-directed choices than healthy controls, particularly after losses. There was no difference in the strength of the habitual component. The group differences did not survive controlling for performance on the Digit Symbol Substitution Task. Conclusion: Chronic alcohol use appears to selectively impair goal-directed function, rather than promoting habitual responding. It appears to do so particularly after nonrewards, and this may be mediated by the effects of alcohol on more general cognitive functions subserved by the prefrontal cortex.Peer Reviewe

Interaction effects on galaxy pairs with Gemini/GMOS - II: oxygen abundance gradients

In this paper we derived oxygen abundance gradients from HII regions located in eleven galaxies in eight systems of close pairs. Long-slit spectra in the range 4400-7300 Å were obtained with the Gemini Multi-Object Spectrograph at Gemini South (GMOS). Spatial profiles of oxygen abundance in the gaseous phase along galaxy disks were obtained using calibrations based on strong emission-lines (N2 and O3N2). We found oxygen gradients significantly flatter for all the studied galaxies than those in typical isolated spiral galaxies. Four objects in our sample, AM1219A, AM1256B, AM 2030A and AM2030B, show a clear break in the oxygen abundance at galactocentric radius R/R₂₅ between 0.2 and 0.5. For AM1219A and AM1256B we found negative slopes for the inner gradients, and for AM2030B we found a positive one. In all these three cases they show a flatter behaviour to the outskirts of the galaxies. For AM2030A, we found a positive-slope outer gradient while the inner one is almost compatible with a flat behaviour. A decrease of star formation efficiency in the zone that corresponds to the oxygen abundance gradient break for AM1219A and AM2030B was found. For the former, a minimum in the estimated metallicities was found very close to the break zone that could be associated with a corotation radius. On the other hand, AM1256B and AM2030A, present a SFR maximum but not an extreme oxygen abundance value. All the four interacting systems that show oxygen gradient breakes the extreme SFR values are located very close to break zones. Hii regions located in close pairs of galaxies follow the same relation between the ionization parameter and the oxygen abundance as those regions in isolated galaxies.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

three fMRI studies

Psychische Erkrankungen werden aus klinischen Gesichtspunkten in Kategorien eingeteilt, die aus einer komplexen Vielzahl von Symptomen mit verschiedenen zugrunde liegenden neurobiologischen Korrelaten bestehen. Der dimensionale Ansatz versucht demgegenüber, neurobiologische Korrelate einzelner Kernsymptome, wie z.B. eine dysfunktionale Belohnungsverarbeitung, zu identifizieren, die diagnoseübergreifend bestehen können. Gegenstand der hier vorliegenden publikationsbasierten Promotion ist die Untersuchung der neurobiologischen Grundlagen der Belohnungsverarbeitung bei verschiedenen psychiatrischen Erkrankungen. Es wurden dabei Patienten mit einer Alkoholabhängigkeit, einer depressiven Episode, einer Schizophrenie, einer manischen Episode und mit der Diagnose Aufmerksamkeitsdefizit- und Hyperaktivitätsstörung (ADHS) sowie gesunde Kontrollprobanden mittels funktioneller Magnetresonanztomographie untersucht. Zusätzlich wurde der Einfluss von moderierenden Variablen wie der medikamentösen Behandlung mit einem selektiven Serotonin-Wiederaufnahmehemmer (SSRI) und von Persönlichkeitsvariablen geprüft. Während der Erwartung einer Belohnung wiesen Patienten mit einer Alkoholabhängigkeit, einer Depression und einer Schizophrenie verminderte Aktivierungen des ventralen Striatums (VS) auf, einer Struktur des mesolimbischen Systems, welche eng mit der Verarbeitung belohnender Reize gekoppelt ist. Darüber hinaus war bei allen Probanden diese striatale Aktivierung mit der Ausprägung depressiver Symptome assoziiert. Bei depressiven Patienten normalisierte sich die Belohnungsverarbeitung nach medikamentöser Therapie bei gleichzeitiger Abnahme der Symptomatik. Patienten mit Alkoholabhängigkeit zeigten zusätzlich eine Assoziation der Belohnungsverarbeitung mit der Impulsivität. Die aufgeführten Studien zeigen eine diagnoseübergreifende Dysfunktion der Belohnungserwartung, die mit depressiver Symptomatik assoziiert ist. Die Befunde unterstreichen die Bedeutung des dimensionalen Ansatzes in der Psychiatrie, der zu einem besseren Verständnis von Kernsymptomen psychischer Erkrankungen und der Entwicklung neuer Therapiestrategien beitragen kann.Mental disorders are classified as clinical categories, which consist of complex patterns of symptoms with diverse neurobiological correlates. A dimensional approach, on the other hand, tries to identify neurobiological signatures of core symptoms, e.g. dysfunctional reward processing, which may be found in diverse mental disorders. This dissertation assesses such neurobiological signatures of reward anticipation in major psychiatric disorders. Using functional magnetic resonance imaging, we examined patients with the diagnoses of alcohol dependence, major depressive disorder (MDD), schizophrenia, an acute manic episode, attention deficit/hyperactivity disorder (ADHD), and healthy controls. In addition, we assessed personality factors, and, in patients with MDD, the influence of treatment with a selective serotonin reuptake inhibitor (SSRI). During reward anticipation, patients with alcohol dependence, MDD and schizophrenia showed diminished functional activation in the ventral striatum (VS), a core region of the mesolimbic reward system strongly implicated in reward learning. Ventral striatal hyporesponsiveness was associated with depressive symptoms across diagnostic categories. In patients with MDD, reward anticipation normalized after successful treatment. In patients with alcohol dependence, we observed an association between reward processing and impulsivity. The present studies identified reward dysfunction across clinical boundaries and observed that it was associated with the severity of depressive symptoms. These findings underline the relevance of a dimensional approach in psychiatry, which can lead to a better understanding of core symptoms of mental disorders, and might help to develop new therapeutic strategies

Surveillance study of hepatitis A virus RNA on fig and date samples

A total of 91 fig and 185 date samples were analyzed by reverse transcription (RT) real-time PCR for the presence of hepatitis A virus (HAV) RNA. Two batches of dates tested positive, and theHAVRNAdetected was genotyped as IA. These findings warrant further development of methods applicable to food which is consumed untreated and is exported from countries in whichHAVis endemic

Diagnostic classification of schizophrenia patients on the basis of regional reward-related FMRI signal patterns.

Functional neuroimaging has provided evidence for altered function of mesolimbic circuits implicated in reward processing, first and foremost the ventral striatum, in patients with schizophrenia. While such findings based on significant group differences in brain activations can provide important insights into the pathomechanisms of mental disorders, the use of neuroimaging results from standard univariate statistical analysis for individual diagnosis has proven difficult. In this proof of concept study, we tested whether the predictive accuracy for the diagnostic classification of schizophrenia patients vs. healthy controls could be improved using multivariate pattern analysis (MVPA) of regional functional magnetic resonance imaging (fMRI) activation patterns for the anticipation of monetary reward. With a searchlight MVPA approach using support vector machine classification, we found that the diagnostic category could be predicted from local activation patterns in frontal, temporal, occipital and midbrain regions, with a maximal cluster peak classification accuracy of 93% for the right pallidum. Region-of-interest based MVPA for the ventral striatum achieved a maximal cluster peak accuracy of 88%, whereas the classification accuracy on the basis of standard univariate analysis reached only 75%. Moreover, using support vector regression we could additionally predict the severity of negative symptoms from ventral striatal activation patterns. These results show that MVPA can be used to substantially increase the accuracy of diagnostic classification on the basis of task-related fMRI signal patterns in a regionally specific way

Quantitative levels of norovirus and hepatitis A virus in bivalve molluscs collected along the food chain in the Netherlands, 2013–2017

Contamination of bivalve molluscs with viruses is well recognized as a food safety risk. A microbiological criterion for norovirus (NoV) and hepatitis A virus (HAV) in shellfish, however, does not exist in the European Union currently. The aim of this study was to evaluate the contamination levels of these viruses for fluctuation over a long period (2013–2017) in oyster (n = 266) and mussel samples (n = 490) using a method based on ISO/TS 15216-1: 2013. Samples were taken at different points in the food chain, either directly post-harvest, at Dutch dispatch centers or in retail stores, from September until March of each year. Altogether, 53.1% of the mussel and 31.6% of the oyster samples tested positive for NoV RNA. Simultaneous presence of NoV GI and GII RNA was observed in 31.6% of mussel and 10.2% of oyster samples. Contamination levels in NoV positive mussel samples collected post-harvest from B-areas were significantly higher than in those collected post-harvest from A-areas, or at dispatch centers or retail stores. Levels in oysters from dispatch were significantly lower than those collected in retail stores. Ready for sale mussels and oysters contained 2.04 and 1.76 mean log10 transformed NoV genome copies/gram (gc/g), respectively. GII levels were at a constant level in ready for sale mussels throughout all sampling periods in the study. This seemed to be true for oysters as well. HAV RNA was detected in only one of the tested mussel samples (n = 392) (typed HAV 1A) and in none of the tested oyster samples (n = 228). Critical evaluation of NoV and HAV levels in shellfish can be of help for risk assessment and risk management actions.</p

Detection and quantification of hepatitis E virus RNA in ready to eat raw pork sausages in the Netherlands

The aim of the present study was to assess raw pork sausages collected on the Dutch market for the presence of hepatitis E virus (HEV) RNA. 46 of 316 (14.6%) products sampled from Dutch retail stores in 2017–2019 were positive for HEV RNA. HEV RNA was detected in 10.8% of “cervelaat” (n = 74), 18.5% of salami (n = 92), 26.1% of “metworst” (n = 46), 16.3% of “snijworst” (n = 43) samples. This was significantly more often than in other raw pork sausages like dried sausages, fuet or chorizo (3.3%, n = 61). The percentage of HEV RNA positive products was not significantly different for products sold as either sliced or unsliced deli meat. The average viral load in positive tested products was 2.76 log10 genome copies per 5 g, incidentally reaching up to 4.5 log10 genome copies per 5 g. The average HEV RNA level was significantly higher in samples collected in 2017 than those in samples collected in 2018, and most of the samples in 2019. Typing by sequence analysis was successful for 33 samples, all revealing genotype 3c. The results support recent epidemiological studies that identified specific raw pork sausages as risk factor for hepatitis E virus infection in the Netherlands. Persons at risk, including Dutch transplant recipients, have been advised to avoid the consumption of raw pork sausages. The study warrants a continuation of monitoring to follow the HEV RNA levels in pork products for use in risk assessments and risk management.</p

Monitoring of pork liver and meat products on the Dutch market for the presence of HEV RNA.

The aim of the present study was to assess pork liver and meat products present on the Dutch market for the presence of hepatitis E virus (HEV) RNA. HEV RNA was detected in 27.3% of 521 products sampled from Dutch retail stores in 2016. 12.7% of livers were positive for HEV RNA (n = 79), 70.7% of liverwurst (n = 99), 68.9% of liver pate (n = 90), but in none of the pork chops (n = 98), fresh sausages (n = 103) or wild boar meat (n = 52). The highest level of HEV RNA contamination was observed in a liver (reaching up to 1 × 1

Environmental testing for norovirus in various institutional settings using catering companies as sentinels for norovirus prevalence among the general population

Noroviruses (NoV) are among the most common causes of viral gastroenteritis (GE) worldwide and can be transmitted from person-to-person, via food or contaminated surfaces. The present study aimed to examine the prevalence of NoV RNA on surfaces in food preparation and sanitary areas in different health care settings and to compare the outcomes with the prevalence in nearby located catering companies, mainly restaurants, for general public, as sentinels. For this purpose, 1087 environmental swabs were taken for NoV analyses from surfaces in 241 institutional departments and 123 catering companies in The Netherlands without a recently reported outbreak of gastro-enteritis in high NoV season only. NoV RNA was detected in 15.1% of the 73 non-hospital health care institutions, 11.1% of the 54 hospital central kitchen departments, 14.9% of the 114 decentralized hospital kitchens (in-patient units) and 4.1% of the 123 nearby located catering companies. Twenty-five of the 49 positive environmental samples were genotyped by sequence analyses. In 7% of the investigated hospitals (4/58), NoV was detected in two or more departments. NoV prevalence was significantly lower in food preparation areas than in sanitary facilities (p<0.05), but only in hospital central kitchen departments and non-hospital health care settings, and not in de-centralized hospital kitchens in in-patient units or in catering companies for the general public. This data suggests that there is a need for education on risks of NoV transmission by food handling of healthcare workers using in ward kitchen facilities

Porcine blood used as ingredient in meat productions may serve as a vehicle for hepatitis E virus transmission.

The aim of the present study was to investigate whether the use of porcine blood(products) in food could be a risk for a hepatitis E virus (HEV) infection. HEV RNA was detected in 33/36 batches of (non-heated) liquid products and in 7/24 spray dried powder products. Contamination levels varied among the products, but were highest in liquid whole blood, plasma and fibrinogen reaching levels of 2.2×102 to 2.8×102 HEV genome copies per 0.2g. Sequence analyses revealed genotype 3 strains, of which two were 100% (493nt) identical to recently diagnosed HEV cases, although no direct epidemiological link was established. The industry provided information on processing of blood products in (ready-to-eat)-meat. From this, it was concluded that blood products as an ingredient of processed meat may not be sufficiently heated prior to consumption, and therefore could be a vehicle for transmission