Self-assembly of focal point oligo-catechol ethylene glycol dendrons on titanium oxide surfaces: adsorption kinetics, surface characterization, and nonfouling properties

This work covers the synthesis of second-generation, ethylene glycol dendrons covalently linked to a surface anchor that contains two, three, or four catechol groups, the molecular assembly in aqueous buffer on titanium oxide surfaces, and the evaluation of the resistance of the monomolecular adlayers against nonspecific protein adsorption in contact with full blood serum. The results were compared to those of a linear poly(ethylene glycol) (PEG) analogue with the same molecular weight. The adsorption kinetics as well as resulting surface coverages were monitored by ex situ spectroscopic ellipsometry (VASE), in situ optical waveguide lightmode spectroscopy (OWLS), and quartz crystal microbalance with dissipation (QCM-D) investigations. The expected compositions of the macromolecular films were verified by X-ray photoelectron spectroscopy (XPS). The results of the adsorption study, performed in a high ionic strength ("cloud-point") buffer at room temperature, demonstrate that the adsorption kinetics increase with increasing number of catechol binding moieties and exceed the values found for the linear PEG analogue. This is attributed to the comparatively smaller and more confined molecular volume of the dendritic macromolecules in solution, the improved presentation of the catechol anchor, and/or their much lower cloud-point in the chosen buffer (close to room temperature). Interestingly, in terms of mechanistic aspects of "nonfouling" surface properties, the dendron films were found to be much stiffer and considerably less hydrated in comparison to the linear PEG brush surface, closer in their physicochemical properties to oligo(ethylene glycol) alkanethiol self-assembled monolayers than to conventional brush surfaces. Despite these differences, both types of polymer architectures at saturation coverage proved to be highly resistant toward protein adsorption. Although associated with higher synthesis costs, dendritic macromolecules are considered to be an attractive alternative to linear polymers for surface (bio)functionalization in view of their spontaneous formation of ultrathin, confluent, and nonfouling monolayers at room temperature and their outstanding ability to present functional ligands (coupled to the termini of the dendritic structure) at high surface densities.

Self-organised transients in a neural mass model of epileptogenic tissue dynamics

Stimulation of human epileptic tissue can induce rhythmic, self-terminating responses on the EEG or ECoG. These responses play a potentially important role in localising tissue involved in the generation of seizure activity, yet the underlying mechanisms are unknown. However, in vitro evidence suggests that self-terminating oscillations in nervous tissue are underpinned by non-trivial spatio-temporal dynamics in an excitable medium. In this study, we investigate this hypothesis in spatial extensions to a neural mass model for epileptiform dynamics. We demonstrate that spatial extensions to this model in one and two dimensions display propagating travelling waves but also more complex transient dynamics in response to local perturbations. The neural mass formulation with local excitatory and inhibitory circuits, allows the direct incorporation of spatially distributed, functional heterogeneities into the model. We show that such heterogeneities can lead to prolonged reverberating responses to a single pulse perturbation, depending upon the location at which the stimulus is delivered. This leads to the hypothesis that prolonged rhythmic responses to local stimulation in epileptogenic tissue result from repeated self-excitation of regions of tissue with diminished inhibitory capabilities. Combined with previous models of the dynamics of focal seizures this macroscopic framework is a first step towards an explicit spatial formulation of the concept of the epileptogenic zone. Ultimately, an improved understanding of the pathophysiologic mechanisms of the epileptogenic zone will help to improve diagnostic and therapeutic measures for treating epilepsy.

Xenomelia: a social neuroscience view of altered bodily self-consciousness

Xenomelia, the "foreign limb syndrome," is characterized by the non-acceptance of one or more of one's own extremities and the resulting desire for elective limb amputation or paralysis. Formerly labeled "body integrity identity disorder" (BIID), the condition was originally considered a psychological or psychiatric disorder, but a brain-centered Zeitgeist and a rapidly growing interest in the neural underpinnings of bodily self-consciousness has shifted the focus toward dysfunctional central nervous system circuits. The present article outlays both mind-based and brain-based views highlighting their shortcomings. We propose that full insight into what should be conceived a "xenomelia spectrum disorder" will require interpretation of individual symptomatology in a social context. A proper social neuroscience of xenomelia respects the functional neuroanatomy of corporeal awareness, but also acknowledges the brain's plasticity in response to an individual's history, which is lived against a cultural background. This integrated view of xenomelia will promote the subfield of consciousness research concerned with the unity of body and self.

Towards Self-Learning Radio-Based Localization Systems

Location-awareness indoors will be an inseparable feature of mobile services/applications in future wireless networks. Its current ubiquitous availability is still obstructed by technological challenges and privacy issues. We propose an innovative approach towards the concept of indoor positioning with main goal to develop a system that is self-learning and able to adapt to various radio propagation environments. The approach combines estimation of propagation conditions, subsequent appropriate channel modelling and optimisation feedback to the used positioning algorithm. Main advantages of the proposal are decreased system set-up effort, automatic re-calibration and increased precision.

Impact of a self-developed planning and self-constructed navigation system on skull base surgery: 10 years experience

CONCLUSION: Our self-developed planning and navigation system has proven its capacity for accurate surgery on the anterior and lateral skull base. With the incorporation of augmented reality, image-guided surgery will evolve into 'information-guided surgery'. OBJECTIVE: Microscopic or endoscopic skull base surgery is technically demanding and its outcome has a great impact on a patient's quality of life. The goal of the project was aimed at developing and evaluating enabling navigation surgery tools for simulation, planning, training, education, and performance. This clinically applied technological research was complemented by a series of patients (n=406) who were treated by anterior and lateral skull base procedures between 1997 and 2006. MATERIALS AND METHODS: Optical tracking technology was used for positional sensing of instruments. A newly designed dynamic reference base with specific registration techniques using fine needle pointer or ultrasound enables the surgeon to work with a target error of < 1 mm. An automatic registration assessment method, which provides the user with a color-coded fused representation of CT and MR images, indicates to the surgeon the location and extent of registration (in)accuracy. Integration of a small tracker camera mounted directly on the microscope permits an advantageous ergonomic way of working in the operating room. Additionally, guidance information (augmented reality) from multimodal datasets (CT, MRI, angiography) can be overlaid directly onto the surgical microscope view. The virtual simulator as a training tool in endonasal and otological skull base surgery provides an understanding of the anatomy as well as preoperative practice using real patient data. RESULTS: Using our navigation system, no major complications occurred in spite of the fact that the series included difficult skull base procedures. An improved quality in the surgical outcome was identified compared with our control group without navigation and compared with the literature. The surgical time consumption was reduced and more minimally invasive approaches were possible. According to the participants' questionnaires, the educational effect of the virtual simulator in our residency program received a high ranking.

Connectionism as metaphor: Towards an integrated, unified conception of self-system and individual difference

Comments on an article by Kashima et al. (see record 2007-10111-001). In their target article Kashima and colleagues try to show how a connectionist model conceptualization of the self is best suited to capture the self's temporal and socio-culturally contextualized nature. They propose a new model and to support this model, the authors conduct computer simulations of psychological phenomena whose importance for the self has long been clear, even if not formally modeled, such as imitation, and learning of sequence and narrative. As explicated when we advocated connectionist models as a metaphor for self in Mischel and Morf (2003), we fully endorse the utility of such a metaphor, as these models have some of the processing characteristics necessary for capturing key aspects and functions of a dynamic cognitive-affective self-system. As elaborated in that chapter, we see as their principal strength that connectionist models can take account of multiple simultaneous processes without invoking a single central control. All outputs reflect a distributed pattern of activation across a large number of simple processing units, the nature of which depends on (and changes with) the connection weights between the links and the satisfaction of mutual constraints across these links (Rummelhart & McClelland, 1986). This allows a simple account for why certain input features will at times predominate, while others take over on other occasions. (PsycINFO Database Record (c) 2008 APA, all rights reserved)

Stem cell-related "self-renewal" signature and high epidermal growth factor receptor expression associated with resistance to concomitant chemoradiotherapy in glioblastoma

PURPOSE: Glioblastomas are notorious for resistance to therapy, which has been attributed to DNA-repair proficiency, a multitude of deregulated molecular pathways, and, more recently, to the particular biologic behavior of tumor stem-like cells. Here, we aimed to identify molecular profiles specific for treatment resistance to the current standard of care of concomitant chemoradiotherapy with the alkylating agent temozolomide. PATIENTS AND METHODS: Gene expression profiles of 80 glioblastomas were interrogated for associations with resistance to therapy. Patients were treated within clinical trials testing the addition of concomitant and adjuvant temozolomide to radiotherapy. RESULTS: An expression signature dominated by HOX genes, which comprises Prominin-1 (CD133), emerged as a predictor for poor survival in patients treated with concomitant chemoradiotherapy (n = 42; hazard ratio = 2.69; 95% CI, 1.38 to 5.26; P = .004). This association could be validated in an independent data set. Provocatively, the HOX cluster was reminiscent of a "self-renewal" signature (P = .008; Gene Set Enrichment Analysis) recently characterized in a mouse leukemia model. The HOX signature and EGFR expression were independent prognostic factors in multivariate analysis, adjusted for the O-6-methylguanine-DNA methyltransferase (MGMT) methylation status, a known predictive factor for benefit from temozolomide, and age. Better outcome was associated with gene clusters characterizing features of tumor-host interaction including tumor vascularization and cell adhesion, and innate immune response. CONCLUSION: This study provides first clinical evidence for the implication of a "glioma stem cell" or "self-renewal" phenotype in treatment resistance of glioblastoma. Biologic mechanisms identified here to be relevant for resistance will guide future targeted therapies and respective marker development for individualized treatment and patient selection.

Phylogenetically independent associations between autonomous self-fertilization and plant invasiveness

Many plant species have been introduced from their native ranges to new continents, but few have become naturalized or, ultimately, invasive. It has been predicted that species that do not require the presence of compatible mates and the services of pollinators for reproduction will be favored in establishment after long-distance dispersal. We tested whether this hypothesis, generally referred to as Baker's law, holds for South African species of Iridaceae ( iris family) that have been introduced in other regions for horticultural purposes. Fruit and seed production of flowers from which pollinators had been experimentally excluded was assessed for 10 pairs of species from nine different genera or subgenera. Each species pair comprised one naturalized and one nonnaturalized species, all of which are used in international horticulture. On average, species of Iridaceae that have become naturalized outside their native ranges showed a higher capacity for autonomous fruit and seed production than congeneric species that have not become naturalized. This was especially true for the naturalized species that are considered to be invasive weeds. These results provide strong evidence for the role of autonomous seed production in increasing potential invasiveness in plants.

The assessment of mindfulness with self-report measures: existing scales and open issues

During recent years, mindfulness-based approaches have been gaining relevance for treatment in clinical populations. Correspondingly, the empirical study of mindfulness has steadily grown; thus, the availability of valid measures of the construct is critically important. This paper gives an overview of the current status in the field of self-report assessment of mindfulness. All eight currently available and validated mindfulness scales (for adults) are evaluated, with a particular focus on their virtues and limitations and on differences among them. It will be argued that none of these scales may be a fully adequate measure of mindfulness, as each of them offers unique advantages but also disadvantages. In particular, none of them seems to provide a comprehensive assessment of all aspects of mindfulness in samples from the general population. Moreover, some scales may be particularly indicated in investigations focusing on specific populations such as clinical samples (Cognitive and Affective Mindfulness Scale, Southampton Mindfulness Questionnaire) or meditators (Freiburg Mindfulness Inventory). Three main open issues are discussed: (1) the coverage of aspects of mindfulness in questionnaires; (2) the nature of the relationships between these aspects; and (3) the validity of self-report measures of mindfulness. These issues should be considered in future developments in the self-report assessment of mindfulness.

Let’s collaborate, but I will be the first author! Exploring the importance of the first authorship for IS researchers

Collaboration among researchers is typically seen as the quintessence of academic excellence, leading to improvements in the research quality, capitalization on the diversity of perspectives and gains in productivity. Despite these benefits, many research teams find themselves torn by competition, antagonism and resentment. Desire to be the first author and resultant underperformance of non-first co-authors is often at the root of these conflicts. At the same time little is known about what motivates researchers in general and IS researchers in particular to engage as first authors. To fill this gap, this study uses survey methodology to explore the attitudes of IS researchers and their resulting behavior when it comes to authors order. Qualitative and quantitative evidence collected from 398 IS researchers is used to support our analysis. We find that researchers’ desire to be the first authors is mainly driven by such determinants as career aspirations, visibility, leadership and sense of ownership, and less so by the desire to satisfy their self-esteem and self-actualization needs. In addition, the value placed on being the first author appears to be the function of researchers’ career level, with Ph.D. students attaching significantly higher value to it than senior scholars.

Internet-based individually versus group guided self-help treatment for social anxiety disorder: protocol of a randomized controlled trial

BACKGROUND: Social anxiety disorder (SAD) is one of the most common mental disorders and causes subjective suffering and economic burden worldwide. Although effective treatments are available, a lot of cases go untreated. Internet-based self-help is a low-threshold and flexible treatment alternative for SAD. Various studies have already shown that internet-based self-help can be effective to reduce social phobic symptoms significantly. Most of the interventions tested include therapist support, whereas the role of peer support within internet-based self-help has not yet been fully understood. There is evidence suggesting that patients' mutual exchange via integrated discussion forums can increase the efficacy of internet-based treatments. This study aims at investigating the added value of therapist-guided group support on the treatment outcome of internet-based self-help for SAD. METHODS/DESIGN: The study is conducted as a randomized controlled trial. A total of 150 adults with a diagnosis of SAD are randomly assigned to either a waiting-list control group or one of the active conditions. The participants in the two active conditions use the same internet-based self-help program, either with individual support by a psychologist or therapist-guided group support. In the group guided condition, participants can communicate with each other via an integrated, protected discussion forum. Subjects are recruited via topic related websites and links; diagnostic status will be assessed with a telephone interview. The primary outcome variables are symptoms of SAD and diagnostic status after the intervention. Secondary endpoints are general symptomology, depression, quality of life, as well as the primary outcome variables 6 months later. Furthermore, process variables such as group processes, the change in symptoms and working alliance will be studied. DISCUSSION: The results of this study should indicate whether group-guided support could enhance the efficacy of an internet-based self-help treatment for SAD. This novel treatment format, if shown effective, could represent a cost-effective option and could further be modified to treat other conditions, as well.

Relations between adolescents' self-evaluations, time perspectives, motivation for school and their achievement in different countries and at different ages

The present study focused on the relations between the self-efficacy, social self-concept, time perspectives, school investment and academic achievement of students in four different European countries and in different adolescence periods. A total of 1623 students completed questionnaires. The relations between the concepts proved not to be specific to the Western or to the former Communist bloc countries studied. The expected general decline in investment and academic achievement over the adolescence period showed up in all four countries studied. Contrary to our hypothesis, however, this decline could not be explained by growing influences of either social self-concept or time perspectives regarding personal development on their investment. In fact, the effects of social self-concept were strongest for the youngest adolescence group. Students’ social self-concept was the best predictor for their investment, while self-efficacy proved to predict academic achievement best in all adolescence periods.

Effects of overt self-­talk on team partners’ other-efficacy and performance in a golf putting task

Introduction According to Lent and Lopez’ (2002) tripartite view of efficacy beliefs, members of a team form beliefs about the efficacy of their team partners. This other-efficacy belief can influence individual performance as shown by Dunlop, Beatty, and Beauchamp (2011) in their experimental study using manipulated performance feedback to alter other-efficacy beliefs. Participants holding favorable other-efficacy beliefs outperformed those with lower other--‐efficacy beliefs. Antecedents of such other-efficacy beliefs are amongst others perceptions regarding motivation and psychological factors of the partner (Jackson, Knapp, & Beauchamp, 2008). Overt self-talk could be interpreted as the manifestation of such motivational or psychological factors. In line with this assumption, in an experimental study using dubbed videos of the same segment of a tennis match, Van Raalte, Brewer, Cornelius, and Petitpas (2006) found that players were perceived more favorably (e.g., more concentrated, and of higher ability levels) when shown with dubbed positive self-talk as compared to dubbed negative or no dubbed self--‐talk. Objectives The aim of the study was to examine the possible effects of a confederate’s overt self-talk on participants’ other-efficacy beliefs and performance in a team setting. Method In a laboratory experiment (between-subjects, pre-post-test design, matched by pretest performance) 89 undergraduate students (female = 35, M = 20.81 years, SD = 2.34) participated in a golf putting task together with a confederate (same gender groups). Depending on the experimental condition (positive, negative, or no self-talk), the confederate commented his or her putts according to a self-talk script. Bogus performance feedback assured that the performance of the confederate was held constant. Performance was measured as the distance to the center of the target, other-efficacy by a questionnaire. Results The data collection has just finished and the results of repeated measures analyses of variance will be presented and discussed at the congress. We expect to find higher other-efficacy beliefs and better individual performance in the positive self-talk condition. References Dunlop, W.L., Beatty, D.J., & Beauchamp, M.R. (2011). Examining the influence of other-efficacy and self-efficacy on personal performance. Journal of Sport & Exercise Psychology, 33, 586-593. Jackson, B., Knapp, P., & Beauchamp, M.R. (2008). Origins and consequences of tripartite efficacy beliefs within elite athlete dyads. Journal of Sport and Exercise Psychology, 30, 512-540. Lent, R.W., & Lopez, F.G. (2002). Cognitive ties that bind: A tripartite view of efficacy beliefs in growth--‐promoting relationships. Journal of Social and Clinical Psychology, 21, 256-286. Van Raalte, J.L., Brewer, B.W, Cornelius, A.E., & Petitpas, A.J. (2006). Self-presentational effects of self-talk on perceptions of tennis players. Hellenic Journal of Psychology, 3, 134-149.

Messung dispositioneller Selbstkontroll-Kapazität: Eine deutsche Adaptation der Kurzform der Self-Control Scale (SCS-K-D)

Self-control is defined as the overriding or modification of one’s own response tendencies. Dispositional self control capacity is positively linked to various kinds of adaptive behavior. In order to economically measure self-control capacity in German-speaking samples, the brief version of the Self-Control Scale by Tangney, Baumeister and Boone (2004) was adapted into German. The translated entire Self-Control Scale consisting of 36 items was administered to university students (N = 316, study 1) and secondary school students (N = 335, study 2). The brief version consisting of 13 items, which were included in the entire scale, proved to be one-dimensional, reliable, and valid in terms of expected correlations with criteria. The comparison between the brief and the entire scale showed that the costs of the more economical brief measure with regard to reliability and validity are low.

DNA-Grafted Supramolecular Polymers: Helical Ribbon Structures Formed by Self-Assembly of Pyrene-DNA Chimeric Oligomers

The controlled arraying of DNA strands on adaptive polymeric platforms remains a challenge. Here, the noncovalent synthesis of DNA-grafted supramolecular polymers from short chimeric oligomers is presented. The oligomers are composed of an oligopyrenotide strand attached to the 5′-end of an oligodeoxynucleotide. The supramolecular polymerization of these oligomers in an aqueous medium leads to the formation of one-dimensional (1D) helical ribbon structures. Atomic force and transmission electron microscopy show rod-like polymers of several hundred nanometers in length. DNA-grafted polymers of the type described herein will serve as models for the development of structurally and functionally diverse supramolecular platforms with applications in materials science and diagnostics.