Stephan Kolassa

Dr. Stephan Kolassa

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Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2022 in International Journal of Forecasting
Verified
Journal Article
Closed access
RFRobert Fildes
Robert Fildes
SMShaohui Ma
Shaohui Ma
SKStephan Kolassa
Stephan Kolassa

1 July 2016 in European Journal of Operational Research
Verified
Journal Article
Open access
ASAris A. Syntetos
Aris A. Syntetos
ZBZied Babai
Zied Babai
JBJohn E. Boylan
John E. Boylan
SKStephan Kolassa
Stephan Kolassa
KNKonstantinos Nikolopoulos
Konstantinos Nikolopoulos
Supply Chain Forecasting (SCF) goes beyond the operational task of extrapolating demand requirements at one echelon. It involves complex issues such as supply chain coordination and sharing of information between multiple stakeholders. Academic research in SCF has tended to neglect some issues that are important in practice. In areas of practical relevance, sound theoretical developments have rarely been translated into operational solutions or integrated in state-of-the-art decision support systems. Furthermore, many experience-driven heuristics are increasingly used in everyday business practices. These heuristics are not supported by substantive scientific evidence; however, they are sometimes very hard to outperform. This can be attributed to the robustness of these simple and practical solutions such as aggregation approaches for example (across time, customers and products). This paper provides a comprehensive review of the literature and aims at bridging the gap between the theory and practice in the existing knowledge base in SCF. We highlight the most promising approaches and suggest their integration in forecasting support systems. We discuss the current challenges both from a research and practitioner perspective and provide a research and application agenda for further work in this area. Finally, we make a contribution in the methodology underlying the preparation of review articles by means of involving the forecasting community in the process of deciding both the content and structure of this paper

10 June 2014 in Translational Psychiatry
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Journal Article
Open access
PDF file
AKAlexander Karabatsiakis
Alexander Karabatsiakis
CBC Böck
C Böck
JSJ Salinas-Manrique
J Salinas-Manrique
SKStephan Kolassa
Stephan Kolassa
ECE Calzia
E Calzia
IKIris Kolassa
Iris Kolassa
Mitochondrial dysfunction might have a central role in the pathophysiology of depression. Phenotypically, depression is characterized by lack of energy, concentration problems and fatigue. These symptoms might be partially explained by reduced availability of adenosine triphosphate (ATP) as a consequence of impaired mitochondrial functioning. This study investigated mitochondrial respiration in peripheral blood mononuclear cells (PBMCs), an established model to investigate the pathophysiology of depression. Mitochondrial respiration was assessed in intact PBMCs in 22 individuals with a diagnosis of major depression (MD) compared with 22 healthy age-matched controls using high-resolution respirometry. Individuals with MD showed significantly impaired mitochondrial functioning: routine and uncoupled respiration as well as spare respiratory capacity, coupling efficiency and ATP turnover-related respiration were significantly lower in the MD compared with the control group. Furthermore, mitochondrial respiration was significantly negatively correlated with the severity of depressive symptoms, in particular, with loss of energy, difficulties concentrating and fatigue. The results suggest that mitochondrial dysfunction contributes to the biomolecular pathophysiology of depressive symptoms. The decreased immune capability observed in MD leading to a higher risk of comorbidities could be attributable to impaired energy supply due to mitochondrial dysfunction. Thus mitochondrial respiration in PBMCs and its functional consequences might be an interesting target for new therapeutical approaches in the treatment of MD and immune-related comorbidities.

1 February 2010 in Biological Psychiatry
Verified
Journal Article
Closed access
IKIris Kolassa
Iris Kolassa
SKStephan Kolassa
Stephan Kolassa
VEVerena Ertl
Verena Ertl
APAndreas Papassotiropoulos
Andreas Papassotiropoulos
DQDominique J.-F. De Quervain
Dominique J.-F. De Quervain

29 January 2013 in BMC Psychiatry
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Journal Article
Open access
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HGHannah Gola
Hannah Gola
HEHarald Engler
Harald Engler
ASAnnette Sommershof
Annette Sommershof
HAHannah Adenauer
Hannah Adenauer
SKStephan Kolassa
Stephan Kolassa
IKIris Kolassa
Iris Kolassa
Posttraumatic stress disorder (PTSD) is associated with an enhanced risk for cardiovascular and other inflammatory diseases. Chronic low-level inflammation has been suggested as a potential mechanism linking these conditions. We investigated plasma cytokine levels as well as spontaneous and lipopolysaccharide (LPS)-stimulated cytokine production by peripheral blood mononuclear cells (PBMCs) in a group of 35 severely traumatized PTSD patients compared to 25 healthy controls. Spontaneous production of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α by isolated PBMCs was significantly higher in the PTSD compared to the control group and even correlated with PTSD symptom severity within the PTSD group. In contrast, circulating plasma levels of pro- and anti-inflammatory cytokines such as IL-6, IL-8, IL-10, TNF-α, or monocyte chemotactic protein (MCP)-1 were not significantly altered in PTSD patients compared to healthy controls. Our findings indicate that PBMCs of PTSD patients are already pre-activated in vivo, providing further evidence for low-grade inflammation in PTSD. This might possibly represent one psychobiological pathway from PTSD to poor physical health.

1 September 2010 in Psychological Trauma: Theory, Research, Practice, and Policy
Verified
Journal Article
Closed access
IKIris-Tatjana Kolassa
Iris-Tatjana Kolassa
VEVerena Ertl
Verena Ertl
CECindy Eckart
Cindy Eckart
SKStephan Kolassa
Stephan Kolassa
LOLamaro P. Onyut
Lamaro P. Onyut
TEThomas Elbert
Thomas Elbert