Stereoscopic motion analysis in densely packed clusters: 3D analysis of the shimmering behaviour in Giant honey bees

<p>Abstract</p> <p>Background</p> <p>The detailed interpretation of mass phenomena such as human escape panic or swarm behaviour in birds, fish and insects requires detailed analysis of the 3D movements of individual participants. Here, we describe the adaptation of a 3D stereoscopic imaging method to measure the positional coordinates of individual agents in densely packed clusters. The method was applied to study behavioural aspects of shimmering in Giant honeybees, a collective defence behaviour that deters predatory wasps by visual cues, whereby individual bees flip their abdomen upwards in a split second, producing Mexican wave-like patterns.</p> <p>Results</p> <p>Stereoscopic imaging provided non-invasive, automated, simultaneous, <it>in-situ </it>3D measurements of hundreds of bees on the nest surface regarding their thoracic position and orientation of the body length axis. <it>Segmentation </it>was the basis for the <it>stereo matching</it>, which defined correspondences of individual bees in pairs of stereo images. Stereo-matched "agent bees" were re-identified in subsequent frames by the <it>tracking </it>procedure and <it>triangulated </it>into real-world coordinates. These algorithms were required to calculate the three spatial motion components (dx: horizontal, dy: vertical and dz: towards and from the comb) of individual bees over time.</p> <p>Conclusions</p> <p>The method enables the assessment of the 3D positions of individual Giant honeybees, which is not possible with single-view cameras. The method can be applied to distinguish at the individual bee level active movements of the thoraces produced by abdominal flipping from passive motions generated by the moving bee curtain. The data provide evidence that the z-deflections of thoraces are potential cues for colony-intrinsic communication. The method helps to understand the phenomenon of collective decision-making through mechanoceptive synchronization and to associate shimmering with the principles of wave propagation. With further, minor modifications, the method could be used to study aspects of other mass phenomena that involve active and passive movements of individual agents in densely packed clusters.</p

Systematic Association Mapping Identifies NELL1 as a Novel IBD Disease Gene

Crohn disease (CD), a sub-entity of inflammatory bowel disease (IBD), is a complex polygenic disorder. Although recent studies have successfully identified CD-associated genetic variants, these susceptibility loci explain only a fraction of the heritability of the disease. Here, we report on a multi-stage genome-wide scan of 393 German CD cases and 399 controls. Among the 116,161 single-nucleotide polymorphisms tested, an association with the known CD susceptibility gene NOD2, the 5q31 haplotype, and the recently reported CD locus at 5p13.1 was confirmed. In addition, SNP rs1793004 in the gene encoding nel-like 1 precursor (NELL1, chromosome 11p15.1) showed a consistent disease-association in independent German population- and family-based samples (942 cases, 1082 controls, 375 trios). Subsequent fine mapping and replication in an independent sample of 454 French/Canadian CD trios supported the authenticity of the NELL1 association. Further confirmation in a large German ulcerative colitis (UC) sample indicated that NELL1 is a ubiquitous IBD susceptibility locus (combined p<10−6; OR = 1.66, 95% CI: 1.30–2.11). The novel 5p13.1 locus was also replicated in the French/Canadian sample and in an independent UK CD patient panel (453 cases, 521 controls, combined p<10−6 for SNP rs1992660). Several associations were replicated in at least one independent sample, point to an involvement of ITGB6 (upstream), GRM8 (downstream), OR5V1 (downstream), PPP3R2 (downstream), NM_152575 (upstream) and HNF4G (intron)

Umfrage: Situation der Hochschuldidaktik in Deutschland

Ergebnisse der Umfrage zur Situation der Hochschuldidaktik in Deutschland. Befragung der Zuständigen für Hochschuldidaktik

Lanthanide luminescence from supramolecular hydrogels consisting of bio-conjugated picolinic-acid-based guanosine quadruplexes

The formation of bio-inspired healable lanthanide luminescent hydrogels is detailed. These materials are composed of K(I)-stabilized guanosine quadruplexes (G4) that were bio-conjugated to mannose-derived picolinic acid ligand 1 using boric acid chemistry (G4-1). The supramolecular self-assembly between G4-1 and europium (Eu(III)) was confirmed, including the use of time-gated luminescence spectroscopy. The most stable hydrogel was formed when the ratio between 1 and Eu(III) was 1:1, and this gel was found to retain a helical column. The obtained gel samples were further characterized using techniques, such as scanning electron microscopy (SEM), circular dichroism (CD), and luminescence spectroscopy. We demonstrate that a Eu(III)-centered circularly polarized luminescence (CPL) signal from guanosine hydrogels can be observed even via long-range interaction, whereas the rheology of these gels exhibits their healable properties

What are residual symptoms in schizophrenia spectrum disorder? Clinical description and 1-year persistence within a naturalistic trial

The aim of this study was to evaluate residual symptoms in patients achieving remission according to the consensus criteria and to analyze their potential influence on the patient's outcome one year after discharge. In total, 399 patients suffering from a schizophrenia spectrum disorder were evaluated within a naturalistic study. Remission status was examined using the consensus criteria. Residual symptoms were defined as any symptom present at the time-point of remission following analogous analyses performed in depressed patients. Therefore, a PANSS item with a symptom severity of > 1 (= at least borderline mentally ill) was defined to be a residual symptom. Remitters with and without residual symptoms were compared regarding psychopathology, functioning and side effects. In total, 236 patients (59 %) were remitters at discharge with 94 % of them suffering from at least one residual symptom. The most common residual symptoms were blunted affect (49 %), conceptual disorganization (42 %) and social withdrawal (40 %). A significant association was found between the presence of residual symptoms and the severity of side effects (p < 0.0001) and functioning (p = 0.0003) at discharge as well as between residual symptoms and the risk of relapse and chance of remission one year after discharge. Residual symptoms were highly prevalent in remitted schizophrenia inpatients following the suggested definition. Most residual symptoms were persistent baseline symptoms suggesting an ongoing illness severity. Also, the necessity to re-evaluate the consensus criteria questioning the status of remission in these patients is also pointed out

Influencing factors and predictors of early improvement in the acute treatment of schizophrenia and schizophrenia spectrum disorder

Background: To examine the influencing factors and predictors of early improvement in schizophrenia patients. Methods: 370 patients suffering from a schizophrenia spectrum disorder were examined within a naturalistic multicenter study. Early improvement was defined as a >= 30% PANSS total score reduction within the first two treatment weeks, response as a >= 50% improvement of the PANSS total score from admission to discharge and remission according to the consensus, remission criteria. Baseline and course-related variables such as positive, negative and depressive symptoms, side effects, functioning and subjective well-being were examined regarding their explanatory value for early improvement. Results: 46% of the patients were identified to be early improvers. Of these, 77% became treatment responder at discharge and 74% achieved the consensus remission criteria. Amongst others, early improvers were significantly more often first-episode patients (p = 0.009), with a significantly shorter duration of current episode (p = 0.024) and a shorter duration of the illness (p = 0.0094). A higher PANSS positive subscore (p = 0.0089), a higher score in the Strauss-Carpenter-Prognostic Scale (SCPS) (p < 0.0001), less extrapyramidal side effects (p = 0.0004) at admission and the development of less extrapyramidal side effects within the first two treatment weeks (p = 0.0013) as well as a duration of current episode of <= 6 months (p = 0.0373) were identified to be significant predictors of early improvement. Conclusion: Early improvement is associated with less illness chronicity and seems to be independent of the type of antipsychotic and the antipsychotic dosage applied. The SCPS was found to be a valuable tool to detect early improvers already at the initiation of antipsychotic treatment. (C) 2011 Elsevier Ltd. All rights reserved

Does Clinical Judgment of Baseline Severity and Changes in Psychopathology Depend on the Patient Population? Results of a CGI and PANSS Linking Analysis in a Naturalistic Study

Background: Linking of the Clinical Global Impression (CGI) Scale and the Positive and Negative Syndrome Scale (PANSS) was performed within a naturalistic sample. Furthermore, these linking results were compared with those derived from randomized controlled trials to examine if the baseline severity might influence the linking results. Methods: Biweekly PANSS and CGI ratings were performed from admission to discharge in 398 schizophrenia patients treated within a naturalistic study. Equipercentile linking was performed using the statistical program, R 2.8.1. To evaluate how the naturalistic study design would influence linkage results, a so-called study sample was computed with patients of the naturalistic study fulfilling common inclusion criteria of randomized controlled trials (n = 199). Patients not fulfilling these criteria (less ill sample) and those fulfilling the criteria (study sample) were compared using confidence intervals. Results: We found a considerable difference between the linking of the CGI severity score and the PANSS total score comparing the less ill sample and the study sample. Being considered mildly ill'' at admission in the less ill sample corresponded to a PANSS total score of 47 points and to a PANSS total score of 67 points in the study sample. Considering the linking of the CGI improvement score and PANSS changes, similar results were found for CGI improvement ratings ranging from very much improved'' to minimally improved.'' Conclusions: Despite considerable differences, a 50% PANSS reduction was found to correspond to a clinical rating of much improved, which seems to be a suitable definition for response in clinical drug trials

Add-on Antidepressants in the Naturalistic Treatment of - Schizophrenia Spectrum Disorder - When, Who, and How?

Introduction The aim of this study was to evaluate antidepressant add-on treatment within the acute treatment of schizophrenia spectrum disorder patients. Methods Antidepressant add-on was evaluated in 365 patients within a naturalistic multicenter study. Patients with/without antidepressant add-on were compared regarding clinical and treatment-related variables, response and remission, and remission of depressive and negative symptoms. The efficacy of antidepressant add-on treatment was furthermore analyzed applying marginal structure models. Results Twenty-three percent of the patients received antidepressant add-on for a mean duration of 50.28 (33.42) days. Patients with the diagnosis of a schizoaffective disorder, multiple illness episodes, and a longer duration of their illness as well as those with significantly fewer baseline positive symptoms, more negative and depressive symptoms, more side effects, and less subjective well-being were augmented with antidepressants. At discharge no significant effect of antidepressant add-on treatment was observed in terms of a 25 % improvement (p = 0.2623), a 50 % improvement (p = 0.3946), remission (p = 0.0552), or remission of depressive (p = 0.6336) and negative symptoms (p = 0.8756). Also, when analyzing marginal structure models considering the diagnostic subgroups, no significant effect was found. Discussion Add-on with antidepressants is common. A final recommendation in terms of this strategy's efficacy cannot be given

What happens with schizophrenia patients after their discharge from hospital? Results on outcome and treatment from a real-world 2-year follow-up trial

Aim of the study was to examine the course of schizophrenia patients within 2 years after discharge. Within a multicenter study of the German Competence Network on Schizophrenia, patients suffering from a schizophrenia spectrum disorder were examined regarding their psychopathological improvement, tolerability, and the treatment regime applied during hospitalization and a 2-year follow-up period. Response, remission, the level of everyday functioning, and relapse were furthermore evaluated during the follow-up period using established definitions for these outcome domains. The psychopharmacological treatment was specifically evaluated in terms of a potential association with relapse. 149 patients were available for analysis, with 65% of the patients being in response, 52% in symptomatic remission, and 64% having a satisfiable everyday functioning 2 years after their discharge from hospital. Despite these favorable outcome rates, 63% of the patients suffered from a relapse within the 2-year follow-up period with 86% of these patients being rehospitalized. Discharge non-responder and non-remitter were twice as likely to relapse during follow-up. A significant decrease of side-effects was observed with negligible rates of extrapyramidal side-effects, sedation, and weight gain during follow-up. Patients receiving treatment with atypical antipsychotics were found to have the lowest risk to relapse (p < 0.0001). The results highlight the natural and unsteady course of schizophrenia in most patients underlining the need to develop more specific treatment strategies ensuring ongoing stability and preventing relapse