A task-independent neural representation of subjective certainty in visual perception

Am I really sure? This is a question not only scientists ask themselves but practically everybody every day. A recent study provides behavioral evidence supporting the view that one’s subjective confidence in a decision (i.e., feeling sure that a decision is correct) is represented in a task-independent format. Previous neuroimaging studies identified neural correlates of decision confidence but whether or not these are task-dependent remains unclear. Here, combining two perceptual decision tasks with functional magnetic resonance imaging (fMRI), we provide neural evidence for a task-independent representation of degrees of subjective certainty (i.e., a neural representation of subjective certainty that remains constant across two visual tasks). Importantly, due to the constant stimulus-intensity used this result is independent of task-difficulty and stimulus properties. Our data provide strong evidence for a generic mechanism underlying the computation of subjective perceptual certainty in vision

How a sticky fluid facilitates prey retention in a carnivorous pitcher plant (Nepenthes rafflesiana)

Nepenthes pitcher plants live in nutrient-poor soils and produce large pitfall traps to obtain additional nutrients from animal prey. Previous research has shown that the digestive secretion in N. rafflesiana is a sticky viscoelastic fluid that retains insects much more effectively than water, even after significant dilution. Although the retention of prey is known to depend on the fluid's physical properties, the details of how the fluid interacts with insect cuticle and how its sticky nature affects struggling insects are unclear. In this study, we investigated the mechanisms behind the efficient prey retention in N. rafflesiana pitcher fluid. By measuring the attractive forces on insect body parts moved in and out of test fluids, we show that it costs insects more energy to free themselves from pitcher fluid than from water. Moreover, both the maximum force and the energy required for retraction increased after the first contact with the pitcher fluid. We found that insects sink more easily into pitcher fluid than water and, accordingly, the surface tension of N. rafflesiana pitcher fluid was lower than that of water (60.2 vs. 72.3 mN/m). By analysing the pitcher fluid’s wetting behaviour, we demonstrate that it strongly resists dewetting from all surfaces tested, leaving behind residual films and filaments that can facilitate re-wetting. This inhibition of dewetting may be a further consequence of the fluid's viscoelastic nature and likely represents a key mechanism underlying prey retention in Nepenthes pitcher plants.V.K. and W.F. were funded by the EU Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 642861. S.S. was funded by the Cambridge India Ramanujan Scholarship

Regenwürmer profitieren im ökologischen Landbau von Kleegras als Vorfrucht und von Kleegrasmulch zur organischen Düngung

Die Bedeutung sowohl der Vorfrucht, als auch der Form der organischen Düngung auf die Regenwurmpopulationen wurde in einem Langzeit-Fruchtfolgeversuch untersucht. Beprobt wurde Weizen nach Kleegras oder nach Kartoffel. Die Fruchtfolge wurde entweder mit Rindergülle gedüngt (viehhaltendes System, Abfuhr Kleegras und Gülledüngung) oder spiegelt die Situation in einem viehlosen System (Mulchen des Kleegrases, ohne organische Düngung der Nachfrüchte) wider. Eine Beprobung im Mai 2017 unter insgesamt günstigen Bedingungen belegte, dass die Vorfrucht Kleegras die Reproduktion der Regenwürmer begünstigt, was noch im nachfolgenden Weizen deutlich wurde. Die tiefgrabende Art Lumbricus terrestris profitierte sowohl von Kleegras als Vorfrucht, als auch vom Mulchen des Kleegrases

Only Slight Impact of Predicted Replicative Capacity for Therapy Response Prediction

BACKGROUND: Replication capacity (RC) of specific HIV isolates is occasionally blamed for unexpected treatment responses. However, the role of viral RC in response to antiretroviral therapy is not yet fully understood. MATERIALS AND METHODS: We developed a method for predicting RC from genotype using support vector machines (SVMs) trained on about 300 genotype-RC pairs. Next, we studied the impact of predicted viral RC (pRC) on the change of viral load (VL) and CD4(+) T-cell count (CD4) during the course of therapy on about 3,000 treatment change episodes (TCEs) extracted from the EuResist integrated database. Specifically, linear regression models using either treatment activity scores (TAS), the drug combination, or pRC or any combination of these covariates were trained to predict change in VL and CD4, respectively. RESULTS: The SVM models achieved a Spearman correlation (rho) of 0.54 between measured RC and pRC. The prediction of change in VL (CD4) was best at 180 (360) days, reaching a correlation of rho = 0.45 (rho = 0.27). In general, pRC was inversely correlated to drug resistance at treatment start (on average rho = -0.38). Inclusion of pRC in the linear regression models significantly improved prediction of virological response to treatment based either on the drug combination or on the TAS (t-test; p-values range from 0.0247 to 4 10(-6)) but not for the model using both TAS and drug combination. For predicting the change in CD4 the improvement derived from inclusion of pRC was not significant. CONCLUSION: Viral RC could be predicted from genotype with moderate accuracy and could slightly improve prediction of virological treatment response. However, the observed improvement could simply be a consequence of the significant correlation between pRC and drug resistance

The L76V mutation in HIV-1 protease is potentially associated with hypersusceptibility to protease inhibitors Atazanavir and Saquinavir: is there a clinical advantage?

Background: Although being considered as a rarely observed HIV-1 protease mutation in clinical isolates, the L76V-prevalence increased 1998-2008 in some European countries most likely due to the approval of Lopinavir, Amprenavir and Darunavir which can select L76V. Beside an enhancement of resistance, L76V is also discussed to confer hypersusceptibility to the drugs Atazanavir and Saquinavir which might enable new treatment strategies by trying to take advantage of particular mutations. Results: Based on a cohort of 47 L76V-positive patients, we examined if there might exist a clinical advantage for L76V-positive patients concerning long-term success of PI-containing regimens in patients with limited therapy options. Genotypic- and phenotypic HIV-resistance tests from 47 mostly multi-resistant, L76V-positive patients throughout Germany were accomplished retrospectively 1999-2009. Five genotype-based drug-susceptibility predictions received from online interpretation-tools for Atazanavir, Saquinavir, Amprenavir and Lopinavir, were compared to phenotype-based predictions that were determined by using a recombinant virus assay along with a Virtual Phenotype™(Virco). The clinical outcome of the L76V-adapted follow-up therapy was determined by monitoring viral load for 96 weeks. Conclusions: In this analysis, the mostly used interpretation systems overestimated the L76V-mutation concerning Atazanavir- and SQV resistance. In fact, a clear benefit in drug susceptibility for these drugs was observed in phenotype analysis after establishment of L76V. More importantly, long-term therapy success was significantly higher in patients receiving Atazanavir and/or Saquinavir plus one L76V-selecting drug compared to patients without L76V-selecting agents (p = 0.002). In case of L76V-occurrence ATV and/or SQV may represent encouraging options for patients in deep salvage situations

Shifting cancer care towards Multidisciplinarity: the cancer center certification program of the German cancer society

Background: Over the last decades numerous initiatives have been set up that aim at translating the best available medical knowledge and treatment into clinical practice. The inherent complexity of the programs and discrepancies in the terminology used make it difficult to appreciate each of them distinctly and compare their specific strengths and weaknesses. To allow comparison and stimulate dialogue between different programs, we in this paper provide an overview of the German Cancer Society certification program for multidisciplinary cancer centers that was established in 2003. Main body: In the early 2000s the German Cancer Society assessed the available information on quality of cancer care in Germany and concluded that there was a definite need for a comprehensive, transparent and evidence-based system of quality assessment and control. This prompted the development and implementation of a voluntary cancer center certification program that was promoted by scientific societies, health-care providers, and patient advocacy groups and based on guidelines of the highest quality level (S3). The certification system structures the entire process of care from prevention to screening and multidisciplinary treatment of cancer and places multidisciplinary teams at the heart of this program. Within each network of providers, the quality of care is documented using tumor-specific quality indicators. The system started with breast cancer centers in 2003 and colorectal cancer centers in 2006. In 2017, certification systems are established for the majority of cancers. Here we describe the rationale behind the certification program, its history, the development of the certification requirements, the process of data collection, and the certification process as an example for the successful implementation of a voluntary but powerful system to ensure and improve quality of cancer care. Conclusion: Since 2003, over 1 million patients had their primary tumors treated in a certified center. There are now over 1200 sites for different tumor entities in four countries that have been certified in accordance with the program and transparently report their results from multidisciplinary treatment for a substantial proportion of cancers. This led to a fundamental change in the structure of cancer care in Germany and neighboring countries within one decade

Der frühe Beginn der Zwangsstörung

Einleitung: Die vorliegende Untersuchung geht der Fragestellung nach, ob sich eine Zwangsstörung, die bereits im Kindes- bzw. Jugendalter beginnt, von einer Zwangsstörung, die erst im Erwachsenenalter beginnt, hinsichtlich Schweregrad und Symptomatik unterscheidet. Patienten und Methoden: Eine Stichprobe von 370 Patienten mit Zwangsstörung (ICD-10 F42), die sich zwischen 1998 und 2002 stationär in der Psychosomatischen Klinik Windach befanden, wurde in eine Early-Onset-Gruppe (Störungsbeginn ≤15 Jahre) und in eine Late-Onset-Gruppe (Störungsbeginn ≥16 Jahre) aufgeteilt. Die Gruppen wurden über ICD-10-Diagnosen und Y-BOCSWerte verglichen. Ergebnisse: Beim Schweregrad zeigte sich, dass 20,5% der Early-Onset-Gruppe, aber lediglich 8,7% der Late-Onset-Gruppe unter einer «massiven Zwangsstörung» leiden. Bei der Symptomatik zeigte sich, dass die Early-Onset-Gruppe häufiger die Diagnose «Zwangsgedanken und -handlungen gemischt» (76,9%)erhält als die Late-Onset-Gruppe (61,8%). Außerdem nennt die Early-Onset-Gruppe sowohl für die Gegenwart als auch für die Vergangenheit mehr Symptome als die Late-Onset-Gruppe (Gegenwart 8,2 vs. 7,0; Vergangenheit 5,5 vs. 3,9 Symptomgruppen). Weiter ergaben sich inhaltliche Unterschiede der Zwangsgedanken und Zwangshandlungen. Schlussfolgerungen: Early-Onset-Patienten scheinen häufiger von einer massiven Form der Zwangsstörung und einer größeren Symptomvielfalt betroffen zu sein als Late-Onset-Patienten. Ob es sich bei der Zwangsstörung mit Beginn im Kindes- und Jugendalter um einen abgrenzbaren Subtypus handelt, konnte jedoch in dieser Untersuchung nicht eindeutig geklärt werden und bedarf weiterer Forschungen.Introduction: This study investigates if obsessive compulsive disorder with early onset differs in severity and symptomatology from that with late onset. Patients and Methods: A sample of 370 patients with obsessive compulsive disorder (OCD; ICD 10 F42) who received in-patient treatment at the psychosomatic clinic of Windach between 1998 and 2002 were divided into an early-onset group (onset ≤15 years) and a late-onset group (onset ≥16 years). Groups were compared regarding ICD-10 diagnosis and Y-BOCS scores. Results: Considering severity of the disorder 20.5% of the early-onset group but merely 8.7% of the late-onset group suffered from an extreme form of OCD. With respect to symptomatology, the early-onset group was diagnosed with ‘obsessions and compulsions, mixed’ (76.9%) more often than the lateonset group (61.8%). Also, the early-onset group reported a wider variety of symptoms both for the present and for the past than the late-onset group (present 8,2 vs 7.0; past 5.5 vs 3.9 types of symptoms). There were also differences in the content of rumination and types of compulsive rituals. Conclusions: Patients with early-onset OCD seem to be more frequently affected by an extreme form of OCD and to experience a higher variety of symptoms than patients with late-onset OCD. If early-onset OCD can be considered a distinct subtype could not be answered unequivocally by the results of this study. This question needs additional research

Resilience trinity: safeguarding ecosystem functioning and services across three different time horizons and decision contexts

Ensuring ecosystem resilience is an intuitive approach to safeguard the functioning of ecosystems and hence the future provisioning of ecosystem services (ES). However, resilience is a multi-faceted concept that is difficult to operationalize. Focusing on resilience mechanisms, such as diversity, network architectures or adaptive capacity, has recently been suggested as means to operationalize resilience. Still, the focus on mechanisms is not specific enough. We suggest a conceptual framework, resilience trinity, to facilitate management based on resilience mechanisms in three distinctive decision contexts and time-horizons: i) reactive, when there is an imminent threat to ES resilience and a high pressure to act, ii) adjustive, when the threat is known in general but there is still time to adapt management, and iii) provident, when time horizons are very long and the nature of the threats is uncertain, leading to a low willingness to act. Resilience has different interpretations and implications at these different time horizons, which also prevail in different disciplines. Social ecology, ecology, and engineering are often implicitly focussing on provident, adjustive, or reactive resilience, respectively, but these different notions and of resilience and their corresponding social, ecological, and economic trade-offs need to be reconciled. Otherwise, we keep risking unintended consequences of reactive actions, or shying away from provident action because of uncertainties that cannot be reduced. The suggested trinity of time horizons and their decision contexts could help ensuring that longer-term management actions are not missed while urgent threats to ES are given priority