University of Marburg

About: University of Marburg is a education organization based out in Marburg, Germany. It is known for research contribution in the topics: Population & Gene. The organization has 23195 authors who have published 42907 publications receiving 1506069 citations. The organization is also known as: Philipps University of Marburg & Philipps-Universität.

Rational Design of Peptide Antibiotics by Targeted Replacement of Bacterial and Fungal Domains

Abstract: Peptide synthetases involved in the nonribosomal synthesis of peptide secondary metabolites possess a highly conserved domain structure. The arrangement of these domains within the multifunctional enzymes determines the number and order of the amino acid constituents of the peptide product. A general approach has been developed for targeted substitution of amino acid-activating domains within the srfA operon, which encodes the protein templates for the synthesis of the lipopeptide antibiotic surfactin in Bacillus subtilis. Exchange of domain-coding regions of bacterial and fungal origin led to the construction of hybrid genes that encoded peptide synthetases with altered amino acid specificities and the production of peptides with modified amino acid sequences.

Deficits in emotion-regulation skills predict alcohol use during and after cognitive-behavioral therapy for alcohol dependence.

Abstract: Alcohol dependence (AD) is the most serious form of alcohol-use disorder. AD is associated with intense mental, physical, and functional impairment; high societal costs; and long-term suffering by both the dependent individual and the individual’s family members (e.g., Caetano, Nelson, & Cunradi, 2001). However, AD is also fairly widespread, with a 12-month prevalence rate of nearly 4% in the general population (Hasin, Stinson, Ogburn, & Grant, 2007). Despite the development and implementation of several empirically supported treatments, only about 25% of clients have been found to remain abstinent during the first year following treatment termination (Miller, Walters, & Bennett, 2001). Thus, there is a strong and pressing need to improve the efficacy of treatment for AD. According to the relapse prevention model proposed by Marlatt and colleagues (Marlatt & Witkiewitz, 2005), relapse is likely to occur when at-risk individuals are confronted with high-risk situations and lack the coping skills necessary to deal with such situations effectively. Consistent with this model, a number of studies have focused on identifying specific high-risk situations. Extensive evidence from these studies has shown that negative affect is one of the most prominent factors associated with relapse to maladaptive drinking. First, AD is highly associated with affect-related disorders, such as anxiety, depression, and borderline personality disorder (Gregory et al., 2008; Hasin et al., 2007), and individuals with co-occurring symptoms of these disorders display significantly higher rates of relapse after treatment (Bradizza, Stasiewicz, & Paas, 2006). Second, the majority of clients retrospectively attribute relapse to negative affective states (Lowman, Allen, & Stout, 1996; Zywiak, Connors, Maisto, & Westerberg, 1996). Third, negative affect -- such as stress/nervousness, anxiety, anger, dysphoric/depressed mood, feelings of loneliness/uselessness/boredom -- predicts subsequent desire to drink/drinking-level in epidemiological studies and relapse in treatment-outcome studies (Falk, Yi & Hilton, 2008; Gamble et al., 2010; Hodgins, el-Guebaly, & Armstrong, 1995; Swendsen et al., 2000; Willinger et al., 2002). Fourth, in laboratory paradigms, the induction of negative affect was shown to predict increased urges to drink and increased expectancies of relief after drinking (Cooney, Litt, Morse, Bauer & Gaupp, 1997; Birch et al., 2004; Sinha et al., 2009). Fifth, interventions focusing on the reduction of depressed mood or anxiety symptoms have been shown to decrease relapse and severity of alcohol use disorders (Brown, Evans, Miller, Burgess, & Mueller, 1997; Watt, Stewart, Birch, & Bernier, 2006), and interventions with a strong focus on emotion-regulation skills, such as dialectical behavioral therapy (Linehan, 1993a) have been shown to reduce substance use (including alcohol) in clients suffering from borderline personality disorder (Harned et al., 2008; Linehan et al., 2002). Finally, evidence suggests that although alcohol may initially reduce negative affect to some extent (Armeli et al., 2003; Kushner et al., 1996; Swendsen et al., 2000), maladaptive use eventually leads to the continuation and potential increase of such affect, thereby generating a vicious cycle contributing to the chronic and escalating nature of AD (Heinz et al., 1998; Koob & Le Moal, 2001; Witkiewitz & Villarroel, 2009). In line with these findings, a number of theories contend that affect regulation is a primary motive for alcohol use; such models include the affective processing model (Baker, Piper, McCarthy, Majeskie, & Fiore, 2004), the motivational model of alcohol use (Cox & Klinger, 1988; Cooper, Frone, Russel, & Mudar, 1995), the stress and negative affect model (Colder & Chassin, 1993), the self-medication model (Khantzian, 1997), the stress response dampening theory (Levenson, Sher, Grossman, Newman, & Newlin, 1980), and the tension reduction hypothesis (Conger, 1956). The implication of these models is that emotion-regulation skills (i.e., skills relevant for “monitoring, evaluating, and modifying emotional reactions, especially their intensive and temporal features, to accomplish one’s goals”; Thompson, 1994, pp. 27-28), should be important -- if not essential -- for preventing relapse in AD. This hypothesis received preliminary support from studies demonstrating that trait emotional intelligence (defined as the ability to be aware of emotions, identify emotions correctly and modify emotions effectively) was negatively associated with alcohol-related problems (Riley & Schutte, 2003) and that emotional intelligence moderated the association between negative emotions and craving for alcohol in AD patients (Cordovil de Sousa Uva et al., 2010). Additional research has shown that abstinent alcoholics report more difficulty effectively regulating their emotions than do social drinkers (Fox, Hong, & Sinha, 2008). However, research has yet to investigate the predictive effects of emotion-regulation skills on alcohol use during and after treatment. To facilitate the utilization of the emotion-regulation framework for clinical purposes, Berking (2010) has synthesized and expanded upon previous theories (e.g., Gross, 1998; Larsen, 2000; Saarni, 1999; Greenberg, 2002) and proposed a skill-based model of emotion regulation. According to the Adaptive Coping with Emotions (ACE) Model (Berking, 2010), effective emotion regulation can be conceptualized as the situation-adapted interplay of the abilities to (a) be aware of emotions, (b) identify and label emotions, (c) correctly interpret emotion-related body sensations, (d) understand the prompts of emotions, (e) actively modify negative emotions to feel better, (f) accept negative emotions when necessary, (g) tolerate negative emotions when they cannot be changed, (h) confront (vs. avoid) distressing situations in order to attain important goals, and (i) compassionately support (encourage, self-soothe) oneself in emotionally distressing situations (in order to counterbalance potential short-term negative effects that engagement in the other skills may have on one’s emotions). Empirical studies have shown that all skills included in the ACE model are significantly associated with various indicators of mental health in clinical and at-risk populations (Berking et al., 2010; Berking, Meier, & Wupperman, 2010; Berking, Orth, Wupperman, Meier, & Caspar, 2008; Berking, Wupperman, et al. 2008; Berking & Znoj, 2008). However, research has not yet investigated whether these skills are associated with AD and whether they facilitate abstinence during or after treatment for AD. In addition, as deficient emotion-regulation skills are likely to be associated with other potential predictors of relapse, such as symptom severity (Langenbucher, Sulesund, Chung, & Morgenstern, 1996), degree of comorbidity (Tate, Brown, Unrod, & Ramo, 2004), cognitive abilities (Blume, Schmaling, & Marlatt, 2005), and negative mood (Hodgins et al., 1995), it is important to investigate whether emotion-regulation skills predict alcohol use beyond these additional factors. Moreover, there is a lack of research comparing the emotion-regulation skills of populations with alcohol-use disorders with those of other clinical populations. Although some evidence exists for the transdiagnostic nature of emotion-regulation skills (Aldao, Nolen-Hoeksema, & Schweizer, 2010), deficits in these skills may be more integral to some disorders than to others. For example, in the emotional disorders (i.e. depression and anxiety) the inability to effectively regulate dysfunctional emotions can be conceptualized as the core of these disorders (Moses & Barlow, 2006); whereas in disorders such as AD, deficits in these skills might be seen as one relevant factor among many that contribute to the onset and maintenance of the disorder (Marlatt & Donovan, 2005). Finally, few studies have assessed a broad range of emotion-regulation skills in order to identify the skills most strongly associated with (changes in) psychopathological symptoms (e.g. Berking, Wupperman, et al., 2008) -- and thus the skills that should be considered important targets in treatment. At this point, no such study is available for AD. Therefore, the major aim of the present study was to test the primary hypotheses that (1) more effective pretreatment emotion-regulation skills would negatively predict alcohol use during treatment and (2) more effective posttreatment emotion-regulation skills would negatively predict alcohol use during the three months following termination of treatment; even when controlling for other predictors potentially related to emotion regulation. Additionally, we investigated whether, (a) more effective pretreatment emotion-regulation skills would be associated with lower pretreatment AD symptom severity, (b) AD patients would report less successful emotion-regulation than did non-clinical controls, but more successful emotion-regulation than did patients meeting criteria for major depressive disorder (MDD), and (c) specific emotion-regulation skills could be identified as particularly important in negatively predicting alcohol use during and after treatment for AD.

Electrospun nanofibers: Internal structure and intrinsic orientation

Abstract: Electrospinning gives rise to polymer nanofibers. The spinning process is characterized by strong deformations of the polymer material taking place during the spinning process and a very rapid structure formation process happening within milliseconds. We were interested in the influence of the peculiar spinning process on the structures of nanofibers. For this purpose, we analyzed the internal structures of nanofibers spun from polyamide-6 and polylactide with an average diameter of about 50 nm. The fibers were partially crystalline, with degrees of crystallinity not significantly smaller than those found for less rapidly quenched and much thicker melt-extruded fibers. The annealing of polyamide fibers at elevated temperatures resulted in a transformation from the disordered γ modification to the more highly ordered α modification, and this again was in close agreement with the response of melt-extruded fibers. The orientation of the crystals along the fiber axis was strongly inhomogeneous: it was, on average, very weak, yet it could be quite pronounced locally. Small elongations of approximately 10% resulted in well-developed homogeneous crystal orientations. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 545–553, 2003