Assimilation of radar altimeter data in numerical wave models: an impact study in two different wave climate regions

An operational assimilation system incorporating significant wave height observations in high resolution numerical wave models is studied and evaluated. In particular, altimeter satellite data provided by the European Space Agency (ESA-ENVISAT) are assimilated in the wave model WAM which operates in two different wave climate areas: the Mediterranean Sea and the Indian Ocean. The first is a wind-sea dominated area while in the second, swell is the principal part of the sea state, a fact that seriously affects the performance of the assimilation scheme. A detailed study of the different impact is presented and the resulting forecasts are evaluated against available buoy and satellite observations. The corresponding results show a considerable improvement in wave forecasting for the Indian Ocean while in the Mediterranean Sea the assimilation impact is restricted to isolated areas

A dynamic model of global value network governance

This paper presents a novel understanding of the changing governance structures in global supply chains. Motivated by the global garment sector, we develop a geographical political economy dynamic model that reflects the interaction between bargaining power and distribution of value among buyer and producer firms. We find that the interplay between these two forces, in combination with the spatial specificities of global production and consolidation, can drive governance structures towards a more symbiotic position

Financialization and the rise of atypical work

The current literature on financialization and the labour process focuses disproportionately on how corporate financialization induces the use of atypical work and largely overlooks the role of household financialization. This paper presents several mechanisms through which household debt and pension fund financialization increase the financial insecurity of employees, which, in turn, can curb their resistance to accepting such work contracts. To assess our arguments, we estimate the effects of corporate and household financialization on involuntary part-time and temporary employment, using a panel dataset of OECD economies. Our findings provide robust support that financialization increases significantly non-standard employment rates for the total workforce and women, but less for older employees.status: publishe

Network configuration as a measure of power in global production networks

Power is one of the key components in understanding and analyzing global production and is central to the analytical frameworks of both GVCs and GPNs. By focusing on firms’ power within GPNs, we are able to draw a novel analytical link between the governance structures of GVCs and network configuration presented in recent versions of GPNs. Using global input- output data, we show that the network structure of global production helps determine the distribution of power among firms in different economic sectors and, consequently, it influences the governance structures of supply networks. More specifically, we find a very high correlation between the distribution of profits and a sector’s position in global production, captured by its (total strength) centrality. Based on this, we are able to provide a quantitative measure of power within global production and its governance structures

Lee-yang zeros and the complexity of the ferromagnetic ising model on bounded-degree graphs

We study the computational complexity of approximating the partition function of the ferromagnetic Ising model in the Lee-Yang circle of zeros given by |λ| = 1, where λ is the external field of the model. Complex-valued parameters for the Ising model are relevant for quantum circuit computations and phase transitions in statistical physics, but have also been key in the recent deterministic approximation scheme for all |λ| ≠ 1 by Liu, Sinclair, and Srivastava. Here, we focus on the unresolved complexity picture on the unit circle, and on the tantalising question of what happens in the circular arc around λ = 1, where on one hand the classical algorithm of Jerrum and Sinclair gives a randomised approximation scheme on the real axis suggesting tractability, and on the other hand the presence of Lee-Yang zeros alludes to computational hardness. Our main result establishes a sharp computational transition at the point λ = 1; in fact, our techniques apply more generally to the whole unit circle |λ| = 1. We show #P-hardness for approximating the partition function on graphs of maximum degree Δ when b, the edge-interaction parameter, is in the interval [EQUATION] and λ is a non-real on the unit circle. This result contrasts with known approximation algorithms when |λ| ≠ 1 or [EQUATION], and shows that the Lee-Yang circle of zeros is computationally intractable, even on bounded-degree graphs. Our inapproximability result is based on constructing rooted tree gadgets via a detailed understanding of the underlying dynamical systems, which are further parameterised by the degree of the root. The ferromagnetic Ising model has radically different behaviour than previously considered anti-ferromagnetic models, and showing our #P-hardness results in the whole Lee-Yang circle requires a new high-level strategy to construct the gadgets. To this end, we devise an elaborate inductive procedure to construct the required gadgets by taking into account the dependence between the degree of the root of the tree and the magnitude of the derivative at the fixpoint of the corresponding dynamical system

Translation and Validation of the Greek Version of the Antipsychotics and Sexual Functioning Questionnaire (ASFQ)

Introduction Sexual dysfunction in patients with psychoses may be associated with the psychiatric illness itself (negative symptoms, such as apathy, and avolition), comorbid somatic health, psychosocial factors (stigmatization, discrimination), and the use of psychotropic drugs. In Greece, research into the study of antipsychotic-induced sexual dysfunction is not sufficient. Aim This study was conducted to translate and validate the Greek version of the Antipsychotics and Sexual Functioning Questionnaire (ASFQ) in a sample of patients receiving antipsychotic treatment. Methods A “forward-backward translation” method was applied. A pilot study was conducted with 15 outpatients with schizophrenia and bipolar disorder under antipsychotics treatment. Patients also completed the “Subjects’ Response to Antipsychotics (SRA)” questionnaire in order to assess the validity of the ASFQ. The ASFQ and the SRA questionnaire were completed twice within 2 weeks. Main outcome measures Reliability (internal consistency and test-retest) and validity were assessed. Results The Greek translation of ASFQ was reliable, with excellent internal consistency (Cronbach's a = 0.90 for men and 0.95 for women in both measurements). In addition, the Spearman correlation coefficient was 1 (P< .001) in all Likert-type questions in both assessments. Finally, Spearman correlation coefficients between ASFQ and SRA were moderately positive to strongly positive (between 0.25 and 1) in both assessments, demonstrating moderate to high validity. Conclusions The Greek version of the ASFQ has proved to be a reliable and valid clinical instrument, hence it can be used in further studies in the Greek population. Angelaki M, Galanis P, Igoumenou A, et al. Translation and Validation of the Greek Version of the Antipsychotics and Sexual Functioning Questionnaire (ASFQ). J Sex Med 2021;9:100334

Socioeconomic conditions and contagion dynamics of the COVID-19 pandemic with and without mitigation measures: Evidence from 185 countries

It is well documented that COVID-19 contagion and mortality rates differed systematically across countries. Less is known, however, on whether these differences could be explained by socioeconomic conditions that may determine both the extent to which individuals voluntarily take protection measures in the absence of Non-Pharmaceutical Interventions (NPIs) or comply with imposed NPIs, when these are in place. Using data from 185 countries, we examine associations of COVID-19 infection and mortality dynamics with socioeconomic conditions, as measured by poverty rates, in periods before and after NPIs have been imposed. We find that, in the initial period of the pandemic, when no NPIs were in place, daily growth of COVID-19 cases and deaths are positively associated with the share of the population living in poverty, whereas, in the following period, when NPIs were implemented, these associations turn negative. We argue that these results could be explained by the fact that NPIs are expected to be more effective in countries with high poverty rates where voluntary physical distancing is low and physical distancing practices are more responsive to imposed measures