Horofunction Compactifications of Symmetric Spaces

We consider horofunction compactifications of symmetric spaces with respect to invariant Finsler metrics. We show that any (generalized) Satake compactification can be realized as a horofunction compactification with respect to a polyhedral Finsler metric.Comment: In the new version, the Convexity Lemma is proven for general norms and not only polyhedral ones. Additionally, smaller changes and corrections were don

Outside the Box: Abstraction-Based Monitoring of Neural Networks

Neural networks have demonstrated unmatched performance in a range of classification tasks. Despite numerous efforts of the research community, novelty detection remains one of the significant limitations of neural networks. The ability to identify previously unseen inputs as novel is crucial for our understanding of the decisions made by neural networks. At runtime, inputs not falling into any of the categories learned during training cannot be classified correctly by the neural network. Existing approaches treat the neural network as a black box and try to detect novel inputs based on the confidence of the output predictions. However, neural networks are not trained to reduce their confidence for novel inputs, which limits the effectiveness of these approaches. We propose a framework to monitor a neural network by observing the hidden layers. We employ a common abstraction from program analysis - boxes - to identify novel behaviors in the monitored layers, i.e., inputs that cause behaviors outside the box. For each neuron, the boxes range over the values seen in training. The framework is efficient and flexible to achieve a desired trade-off between raising false warnings and detecting novel inputs. We illustrate the performance and the robustness to variability in the unknown classes on popular image-classification benchmarks.Comment: accepted at ECAI 202

Into the Unknown: Active Monitoring of Neural Networks

Neural-network classifiers achieve high accuracy when predicting the class of an input that they were trained to identify. Maintaining this accuracy in dynamic environments, where inputs frequently fall outside the fixed set of initially known classes, remains a challenge. The typical approach is to detect inputs from novel classes and retrain the classifier on an augmented dataset. However, not only the classifier but also the detection mechanism needs to adapt in order to distinguish between newly learned and yet unknown input classes. To address this challenge, we introduce an algorithmic framework for active monitoring of a neural network. A monitor wrapped in our framework operates in parallel with the neural network and interacts with a human user via a series of interpretable labeling queries for incremental adaptation. In addition, we propose an adaptive quantitative monitor to improve precision. An experimental evaluation on a diverse set of benchmarks with varying numbers of classes confirms the benefits of our active monitoring framework in dynamic scenarios.Comment: published at RV 202

Contesting the hydrocarbon frontiers: state depoliticizing practices and local responses in Peru

Based on primary sources, this article analyzes 150 participatory events related to planned hydrocarbon projects in Peru (2007-2012). Therein, it sheds light on state depoliticizing practices and local populations' contestations thereof. We argue that participation in the extraction sector has not enabled effective participation and has instead been used to pave the way for expanding the extractive frontiers. We find that the state entity responsible for carrying out the events applied three main depoliticizing practices: (a) the organization of exclusionary participatory processes, (b) the provision of pro-extraction information, and (c) the identification of critical actors and discourses in order to formulate recommendations on how to weaken resistance against the planned activities. This study also reveals that local populations often contested the participatory events and identifies subnational patterns of local contestation. We find that higher degrees of contestation were fueled by previous negative experiences with extraction activities and the existence of local economic alternatives. To assess the histories and results of contestation over specific extractive activities over time, the study draws on monthly conflict reports produced by the Peruvian ombudsperson (2007–2016). We find that local contestation was quite influential, leading to increased social investment programs in the affected areas, the withdrawal of several extraction corporations, and Peru's adoption of the Law on Prior Consultation (2011). However, the long-term prospects of the transformations provoked by repoliticizing processes need to be evaluated in the years to come

Wildlife Disease Monitoring:Methods and Perspectives

In the last few decades, scientific interest in wildlife diseases has steadily grown and has recently been boosted by the SARS-CoV-2 pandemic, which highlighted that the health of humans, livestock, wildlife and, ultimately, of the whole environment is inextricably linked [...

Leprosy in squirrels: an ancient disease in an endangered wildlife host

Leprosy is an ancient human disease that was thought to have been eradicated from the British Isles. The last case of autochthonous human infection was documented in the 1950’s. Natural infection with leprosy bacilli in species other than humans was first described in ninebanded armadillos in the 1970s in the United States of America. Recently, both bacterial species causing leprosy, Mycobacterium leprae and Mycobacterium lepromatosis, were isolated from Eurasian red squirrels (Sciurus vulgaris, ERS) across the British Isles. ERS are endangered in this part of their range, and efforts are made for their protection. This thesis offers insight into important aspects (clinical presentation, pathology, epidemiology) of the basic description of leprosy in live ERS, based on data from two wild British island ERS populations naturally infected with leprosy bacilli. The populations, one in Scotland and one in England, were studied for 18 and 24 months respectively, with live sampling taking place every six months. Additionally, samples from ERS, Eastern grey squirrels (Sciurus carolinensis, GS) and Pallas’s squirrels (Callosciurus erythraeus, PS) were obtained from Britain (ERS, GS), Germany (ERS, PS) and Italy (ERS, GS, PS) and screened for the presence of leprosy bacilli to provide new epidemiological surveillance information on squirrel leprosy. Established, adapted, and novel tests were used to diagnose leprosy in squirrels. Accurate clinical diagnosis is important to identify populations affected by the disease. Serological methods were useful to confirm the clinical diagnosis. Molecular methods were the only way to identify leprosy bacilli in squirrels without clinical signs of disease. A diagnostic decision tree is proposed to allow optimised, consistent use of the methods now available depending on the situation in which a diagnosis is sought. ERS that are infected with M. leprae and develop clinical leprosy usually showed a multibacillary, lepromatous or borderline lepromatous form of the disease. Lepromatous leprosy is characterised by an inability of the host immune response to control bacterial replication and dissemination. Leprosy in ERS progressed slowly, and the intensity of lesions could easily be separated into four categories from mild to severe based on lesion size, structural characteristics and the presence or absence of ulceration. Several months passed between the time when the bacteria first became detectable in an ERS tissues and the onset of clinical disease. Clinical disease then progressed on varying timescales in different individuals, but usually allowed the individuals to thrive for long time frames (months – years). The maximum time period a clinically diseased ERS was followed in this study was 18 months. Prevalence and morbidity differed in individual ERS populations. In one population the total apparent two-year prevalence of leprosy was 36% with a morbidity rate of 22% for the same population and timeframe. In the other the apparent two-year prevalence was only 4% and no clinical cases of leprosy were observed. The presence of leprosy did not have a negative effect on individual ERS or whole populations that could be measured using health indicators such as body condition, weight, general health and ectoparasite burdens. As part of this study, M. leprae was identified in ERS in two new locations within the UK, but not in British GS or any squirrel species in Germany or Italy. The results indicate that leprosy alone is unlikely to be a major factor contributing to ERS mortalities and thus may not be of great conservation concern in this species. Continued research into ERS leprosy in natural systems could provide valuable insight into disease dynamics that may benefit humans and other hosts in a One Health and conservation medicine framework

Schaf- und Ziegenhaltung in der Tiergestützten Intervention

Schafe und Ziegen werden regelmäßig im Rahmen tiergestützter Interventionen (TGI) eingesetzt. Obwohl tiergestützt arbeitende Projekte in Deutschland seit langem existieren, wurde erst durch die in den letzten Jahren angestrebte Professionalisierung dieses Arbeitsfeldes deutlich, wie wenig Informationen über diese Nutzungsform bisher vorhanden sind, die z.B. von den veterinärmedizinischen Überwachungsbehörden oder Praktikern genutzt werden können. Daher soll diese Arbeit darstellen, warum eine Haltung von Schafen und Ziegen in der TGI sinnvoll ist, wie sich solche Haltung und Nutzung aktuell gestaltet, ob sie die Tiere in besonderem Maße belastet, ob Maßnahmen zum Schutz der öffentlichen Gesundheit nötig sind und ob die rechtliche Einordnung der Einrichtungen geeignet ist, das Wohlbefinden der Tiere zu schützen. Zu diesem Zweck wurde zunächst die Relevanz und rechtliche Stellung tiergestützter Arbeit mit Schafen und Ziegen anhand der zum Thema vorhandenen Literatur erarbeitet. Im Folgenden wurden neun Jugendfarmen und Aktivspielplätze in Bayern und Baden-Württemberg besucht (insgesamt 25 Schafe, 32 Ziegen), um durch die Beantwortung eines Fragebogens und eigene Beobachtungen vor Ort einen Eindruck von der ‚Arbeit‘ und Haltung der Tiere in den Einrichtungen zu gewinnen. Um festzustellen, ob Einsatz oder Haltungspraxis die Tiere belasten, wurden der allgemeine Gesundheitszustand und parasitologische Status der Tiere, ihr Grund- und Sozialverhalten und dessen Beeinflussung durch die Anwesenheit von Personen (Direktbeobachtungen), ihr Verhalten gegenüber dem Menschen (Direktbeob-achtungen, Reaktionsproben) sowie ihre Herzfrequenz und Herzratenvariabilität und die Kotkortisolmetabolitenkonzentration über 24-Stunden erfasst. Untersuchungen auf potentielle Zoonoseerreger lieferten Informationen zur Reservoirfunktion der Tiere. Die Schafe und Ziegen werden in den Einrichtungen vorwiegend passiv genutzt. Durch die Übernahme von Verantwortung bei ihrer Versorgung sollen Kinder und Jugendliche im urbanen Umfeld in ihrer Entwicklung gefördert werden, Erfahrungen mit Nutztieren machen und den Tierschutzgedanken verinnerlichen. Die gemeinnützigen Nutztierhaltungen fallen nicht unter die Erlaubnis- und Sachkundepflicht nach §11 TierSchG, sondern unterliegen nur der Beaufsichtigung nach §16 TierSchG. Die besuchten Haltungen sind überwiegend als tiergerecht zu bezeichnen. Die Tiere zeigten keine Verhaltensstörungen und artgemäßes Grundverhalten (z.B. Wiederkauzeit/24-Stunden: Ziegen im Mittel 7 ¾ Stunden, Schafe 9 Stunden). Direkte Personenkontakte waren in allen Einrichtungen deutlich seltener als erwartet (ca. 2 Stunden/Öffnungstag direkter Mensch-Tier-Kontakt möglich). Die Anwesenheit von Personen führte zu keiner signifikanten Zunahme antagonistischer Interaktionen. Der überwiegende Teil der Tiere zeigt eine neutrale bis positive Einstellung gegenüber dem Menschen (z.B. Voluntary-Approach-Test: Annäherung 42,1% der Tiere; sich nicht nähernde Tiere: 24,2% ängstlich, 75,8% desinteressiert). Die Ergebnisse der Kotkortisolmetabolitenbestimmungen stützen die in den Verhaltensbeobachtungen gewonnenen Erkenntnisse. Im Median lag die Kotkortisolmetabolitenkonzentration über 24 Stunden bei Ziegen bei 267 ng/g, bei Schafen bei 244 ng/g. Während der Öffnungszeiten (zusätzliche Bewegungs-möglichkeiten, min. 1 Fütterung) lagen die Werte signifikant höher als vor der Öffnung (Ziegen: 256 ng/g bzw. 353 ng/g, p = 0,003; Schafe: 224 ng/g bzw. 281 ng/g, p = 0,016). Insgesamt ergaben sich keine eindeutigen Hinweise auf eine besondere Belastung. STEC wurden sehr häufig nachgewiesen (Schafe: 100%; Ziegen: 89,3%). Während weder Salmonella spp. noch Coxiella burnetii gefunden wurden, gelang der Nachweis von Staphylococcus spp. bei jeweils 75% der Tiere. Ein Anteil von 25% der Schafe bzw. 14,3% der Ziegen erwiesen sich als Träger von Campylobacter spp. Beide Tierarten sind somit Reservoir für potentielle Zoonoseerreger. Aus den Untersuchungen ist zu schließen, dass für die tiergestützte Arbeit mit Schafen und Ziegen ein gesonderter rechtlicher Rahmen (Betreuungsverträge, Kennzeichnung) sinnvoll ist. Die Art der Nutzung und Haltung der kleinen Wiederkäuer gefährdet das Wohlbefinden der Tiere nicht grundsätzlich und kann neben den förderlichen Effekten für den Menschen zu einer Verbesserung der Stellung von Nutztieren in der Gesellschaft führen. Die Auswahl der Schafe und Ziegen für eine TGI muss das artspezifische und individuelle Verhalten beachten, um ihre Eignung für den angestrebten Einsatz zu gewährleisten. Eine Sensibilisierung tiergestützt Arbeitender für die Thematik Zoonosen und die Implementierung betriebsindividueller Hygiene- und Impfkonzepte ist sinnvoll

Raf-1 Activation Prevents Caspase 9 Processing Downstream of Apoptosome Formation

In many cell types, growth factor removal induces the release of cytochrome-c from mitochondria that leads to activation of caspase-9 in the apoptosome complex. Here, we show that sustained stimulation of the Raf-1/MAPK1,3 pathway prevents caspase-9 activation induced by serum depletion in CCL39/ΔRaf-1:ER fibroblasts. The protective effect mediated by Raf-1 is sensitive to MEK inhibition that is sufficient to induce caspase-9 cleavage in exponentially growing cells. Raf-1 activation does not inhibit the release of cytochrome-c from mitochondria while preventing caspase-9 activation. Gel filtration chromatography analysis of apoptosome formation in cells shows that Raf-1/MAPK1,3 activation does not interfere with APAF-1 oligomerization and recruitment of caspase 9. Raf-1-mediated caspase-9 inhibition is sensitive to emetine, indicating that the protective mechanism requires protein synthesis. However, the Raf/MAPK1,3 pathway does not regulate XIAP. Taken together, these results indicate that the Raf-1/MAPK1,3 pathway controls an apoptosis regulator that prevents caspase-9 activation in the apoptosome complex