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Aims Gender and psychiatric comorbidity seem to influence patients' inter-individual response to Opioid Substitution Treatments (OST) in Opioid Use Disorder (OUD) management. The aim of the study was to assess psychopathological dimensions in an Italian sample of OUD individuals entering a methadone/buprenorphine maintenance program; secondary, we evaluated the possible gender-specific differences within the psychopathological profiles. Methods In a cross-sectional study, we recruited 1052 (792 male; 260 female) OUD subjects receiving OST. All patients underwent a clinical and psychometric evaluation assessing demographics, psychiatric history, psychopathological features via the Symptom Checklist-90-Revised (SCL-90-R), and were prescribed psychopharmacological treatments. Results Our results reveal gender-specific differences in a real-world sample of opioid-maintained OUD individuals attending public addiction services in Italy. Compared to men, women reported higher scores in both General Symptomatic Index (GSI) and in all the SCL-90-R sub-scales. No impact of pharmacological treatment was detected. Finally, regression analysis revealed that being in methadone-maintenance group was significantly associated with high GSI scores in the male, but not female, group. Conclusions Increasing the knowledge of psychopathological dimensions in patients with OST, with relevance to gender differences, is important for a better understanding of factors that influence the outcome and for further development in gender-tailored strategies.

Objectives To evaluate prevalence and severity of constipation and quality of life (QoL) in a cohort of opioid-addicted patients treated with opioid substitution treatments (OST). METHODS: A total of 1057 heroin-dependent patients treated with methadone or buprenorphine were enrolled in a multicenter observational study. Constipation was assessed by Wexner Constipation Scoring System (Wexner CSS), QoL by General Health Questionnaire (GHQ-12). RESULTS: 38.5% patients reported mild constipation, 33.3% reported moderate constipation, 14.8% severe constipation and 5.1% very severe constipation. Mean Wexner CSS score was 6.6 ± 4.8. 44.9% patients showed a GHQ-12 score ≥14; of these 18.3% patients showed a GHQ-12 score ≥20. Mean GHQ score was 13.8 ± 6.5. Mean Wexner CSS score was significantly higher in methadone patients (p = 0.004), in those taking psychoactive drugs (p = 0.0001) and in female (p < 0.0001) with respect to counterparts. Similarly, GHQ-12 mean scores were higher methadone group (p = 0.003), in those taking psychoactive drugs (p < 0.0001), and in female (p = 0.039) with respect to counterparts. ANOVA and ANCOVA showed a significant influence of methadone and female gender on Wexner CSS score while psychoactive drugs significantly influenced both tests. CONCLUSIONS: The present study shows that patients affected by opioid-dependence in OST with methadone and buprenorphine have a high prevalence of constipation and reduced QoL.

In this paper we consider the following question in the spirit of Ramsey theory: Given x ∈ Aω, where A is a finite non-empty set, does there exist a finite coloring of the non-empty factors of x with the property that no factorization of x is monochromatic? We prove that this question has a positive answer using two colors for almost all words relative to the standard Bernoulli measure on Aω. We also show that it has a positive answer for various classes of uniformly recurrent words, including all aperiodic balanced words, and all words x ∈ Aω satisfying λx(n + 1) - λx(n) = 1 for all n sufficiently large, where λx(n) denotes the number of distinct factors of x of length n. © 2014 Elsevier Inc.

We consider the following open question in the spirit of Ramsey theory: Given an aperiodic infinite word w, does there exist a finite coloring of its factors such that no factorization of w is monochromatic? We show that such a coloring always exists whenever w is a Sturmian word or a standard episturmian word. © 2013 Springer-Verlag.

In this paper we prove that for any infinite word w whose set of factors is closed under reversal, the following conditions are equivalent: (I)all complete returns to palindromes are palindromes;(II)P (n) + P (n + 1) = C (n + 1) - C (n) + 2 for all n, where P (resp. C) denotes the palindromic complexity (resp. factor complexity) function of w, which counts the number of distinct palindromic factors (resp. factors) of each length in w.

In this paper, we study combinatorial and structural properties of a new class of finite and infinite words that are 'rich' in palindromes in the utmost sense. A characteristic property of the so-called rich words is that all complete returns to any palindromic factor are themselves palindromes. These words encompass the well-known episturmian words, originally introduced by the second author together with Droubay and Pirillo in 2001 [X. Droubay, J. Justin, G. Pirillo, Episturmian words and some constructions of de Luca and Rauzy, Theoret. Comput. Sci. 255 (2001) 539-553]. Other examples of rich words have appeared in many different contexts. Here we present the first unified approach to the study of this intriguing family of words. Amongst our main results, we give an explicit description of the periodic rich infinite words and show that the recurrent balanced rich infinite words coincide with the balanced episturmian words. We also consider two wider classes of infinite words, namely weakly rich words and almost rich words (both strictly contain all rich words, but neither one is contained in the other). In particular, we classify all recurrent balanced weakly rich words. As a consequence, we show that any such word on at least three letters is necessarily episturmian; hence weakly rich words obey Fraenkel's conjecture. Likewise, we prove that a certain class of almost rich words obeys Fraenkel's conjecture by showing that the recurrent balanced ones are episturmian or contain at least two distinct letters with the same frequency. Lastly, we study the action of morphisms on (almost) rich words with particular interest in morphisms that preserve (almost) richness. Such morphisms belong to the class of P-morphisms that was introduced by Hof, Knill, and Simon in 1995 [A. Hof, O. Knill, B. Simon, Singular continuous spectrum for palindromic Schrödinger operators, Comm. Math. Phys. 174 (1995) 149-159].

In this paper we explore various interconnections between rich words, Sturmian words, and trapezoidal words. Rich words, first introduced by the second and third authors together with J. Justin and S. Widmer, constitute a new class of finite and infinite words characterized by having the maximal number of palindromic factors. Every finite Sturmian word is rich, but not conversely. Trapezoidal words were first introduced by the first author in studying the behavior of the subword complexity of finite Sturmian words. Unfortunately this property does not characterize finite Sturmian words. In this note we show that the only trapezoidal palindromes are Sturmian. More generally we show that Sturmian palindromes can be characterized either in terms of their subword complexity (the trapezoidal property) or in terms of their palindromic complexity. We also obtain a similar characterization of rich palindromes in terms of a relation between palindromic complexity and subword complexity.

Originally introduced and studied by the third and fourth authors (A. Glen and L.Q. Zamboni) together with J. Justin and S. Widmer (2008), "rich words" constitute a new class of finite and infinite words characterized by containing the maximal number of distinct palindromes. Several characterizations of rich words have already been established. A particularly nice characteristic property is that all 'complete returns' to palindromes are palindromes. In this note, we prove that rich words are also characterized by the property that each factor is uniquely determined by its longest palindromic prefix and its longest palindromic suffix.