Human-carnivore coexistence and the responses of spotted hyenas (Crocuta crocuta) to anthropogenic activity in Ngorongoro Conservation Area, Tanzania

Human-wildlife coexistence requires rigorous, interdisciplinary evidence that promotes effective conservation and management actions. Such evidence-based approaches are conducive to coexistence between local communities and conflict-prone wildlife, such as large carnivores. Yet, little is known about the best path to gaining local community acceptance of large carnivore management strategies, the effects of anthropogenic activity on the persistence of large carnivores, and the way large carnivores interact with Threatened wildlife and local communities. This dissertation focuses on the applied ecology and conservation of large carnivores in Ngorongoro Conservation Area (NCA), Tanzania, a multi-use protected area where the local Maasai community lives alongside wildlife. The three objectives of this dissertation are to: (i) identify the best predictors of the acceptance of large carnivore management strategies by local community members, (ii) assess the effects of anthropogenic activity on large carnivore fitness and physiology, and (iii) understand how large carnivores interact with Threatened wildlife and local communities in multi-use protected areas. I use an interdisciplinary approach by combining socio-psychological data from the Maasai community with long-term data on the diet, fitness, and physiology of free-ranging spotted hyenas in the NCA. In Chapter 2, I show that emotions towards and the cultural importance of large carnivores (spotted hyenas (Crocuta crocuta), lions (Panthera leo), and leopards (Panthera pardus)) are much stronger predictors of the acceptance of large carnivore management strategies than livestock depredation is. I also show that depredation by large carnivores is a much smaller source of livestock death than disease and drought are. I demonstrate that spotted hyenas are viewed less positively than both lions and leopards are, though invasive strategies are not accepted for all three species. The results demonstrate that conservation practitioners may focus too much on livestock depredation as the main impediment to coexistence; rather, they may need to target the respectful fostering of positive emotions through community engagement, while accounting for how different species are viewed. In Chapter 3, I investigate the effect of diurnal pastoralism on fitness and physiology in the Ngorongoro Crater spotted hyena population over a 24-year period by exploiting a natural experiment: two of the Crater’s eight spotted hyena clans were exposed to the pastoralism, while the other six were not. By directly measuring the effects of pastoralism on fitness and physiology, I quantify how an anthropogenic activity affects highly conservation-relevant traits. I found no detectable difference in juvenile recruitment (fitness) nor allostatic load (physiology) between the exposed and unexposed clans, indicating that the pastoralism had no major deleterious effect on the spotted hyenas. These results suggest that exposure to anthropogenic activity may be compatible with the persistence of group-living large carnivores, if spatiotemporal overlap between the species’ key behaviors and the activity is limited. Finally, in Chapter 4, I use fecal DNA metabarcoding to show that the Ngorongoro Crater spotted hyena population does not regularly consume the black rhinoceros (Diceros bicornis), a Critically Endangered species. I also show that spotted hyenas at least occasionally leave the Crater to forage, based on detections of both Maasai giraffe (Giraffa camelopardalis tippelskirchi) and domestic animals. Furthermore, I found a positive association between spotted hyena age and the propensity to consume domestic animals, which has implications for conflict mitigation. This dissertation sheds light on (i) the most important variables to target when seeking to gain local acceptance for large carnivore management strategies, (ii) the effects of anthropogenic activity on the fitness and physiology of large carnivores, and (iii) how large carnivores interact with Threatened wildlife and local communities in multi-use protected areas. Altogether, this dissertation is expected to provide valuable knowledge for the optimization of evidence-based large carnivore conservation and human-carnivore coexistence.Die Koexistenz von Menschen und Wildtieren erfordert gezielte, interdisziplinäre Evidenz, um effektive Schutz- und Bewirtschaftungsmaßnahmen zu etablieren. Solche evidenzbasierten Ansätze sind von zentraler Bedeutung um die Koexistenz zwischen lokalen Gemeinschaften und zu Konflikten neigenden Wildtieren, wie z. B. Großraubtieren zu verbessern. Es ist jedoch nur wenig darüber bekannt, wie die Akzeptanz der lokalen Bevölkerung für Strategien zur Bewirtschaftung von Großraubtieren am besten erreicht werden kann, welche Auswirkungen anthropogene Aktivitäten auf den Fortbestand von Großraubtieren haben und wie Großraubtiere mit bedrohten Arten und lokalen Gemeinschaften interagieren. Diese Dissertation konzentriert sich auf die angewandte Ökologie und den Schutz Großraubtiere in der Ngorongoro Conservation Area (NCA), Tansania, eine vielseitig genutzte Landschaft, in dem die lokalen Gemeinschaften von Massai-Hirten neben Wildtieren lebt. Die drei Hauptziele der Dissertation beschäftigen sich mit: (i) der Identifizierung der besten Prädiktoren für die Akzeptanz verschiedener Managementstrategien für Großraubtiere bei Mitgliedern der lokalen Gemeinschaft, (ii) der Bestimmung des Einflusses tageszeitlicher Weidehaltung auf die Fortpflanzungserfolg und Physiologie in Gruppen lebenden Großraubtiere, (iii) verstehen wie Großraubtiere mit bedrohten Arten und lokalen Gemeinschaften in vielseitig genutzten Landschaften interagieren. In dieser Dissertation verwende ich einen interdisziplinären Ansatz, indem ich sozio-psychologische Daten der Massai-Gemeinschaft mit Langzeitdaten über die Ernährung, Fortpflanzungserfolg und Physiologie von Tüpfelhyänen aus einer freilebenden Population in der NCA kombiniere. In Kapitel 2 zeige ich, dass die Emotionen gegenüber und die kulturelle Bedeutung von Großraubtieren (Tüpfelhyänen, Löwen (Panthera leo) und Leoparden (Panthera pardus)) weitaus mehr Einfluss auf die Akzeptanz von Managementmaßnahmen für Großraubtiere haben als es die Gefährdung von Viehbeständen hat. Ich zeige auch, dass die Verluste durch Großraubtiere eine deutlich seltenere Ursache für den Tod von Nutztieren sind als Krankheiten und Dürre. Insgesamt wurden Tüpfelhyänen weniger positiv bewertet als Löwen und Leoparden, obwohl invasive Strategien bei allen drei Arten abgelehnt wurde. Die Ergebnisse zeigen, dass sich Naturschützer möglicherweise zu sehr auf die Viehtötung als Haupthindernis für die Koexistenz konzentrieren; stattdessen wäre es möglicherweise besser sich auf eine respektvolle Stärkung positiver Emotionen durch das Engagement der Gemeinschaft zu konzentrieren und dabei zu berücksichtigen, wie die verschiedenen Arten von der lokalen Gemeinschaft angesehen werden. In Kapitel 3 untersuche ich die Auswirkungen der Tagesweidehaltung auf die Rekrutierung von Jungtieren und die allostatische Belastung der Tupfelhyänenpopulation im Ngorongoro-Krater über einen Zeitraum von 24 Jahren, indem ich ein natürliches Experiment nutze: zwei der acht Tupfelhyänen Clans im Krater waren der Weidehaltung ausgesetzt, die anderen sechs nicht. Durch die direkte Messung der Auswirkungen der Weidewirtschaft auf den Fortpflanzungserfolg und die physiologischen Merkmale quantifiziere ich, wie sich eine anthropogene Aktivität auf äußerst naturschutzrelevante Eigenschaften der Tupfelhyänen auswirkt. Ich konnte keinen nachweisbaren Unterschied bei der Rekrutierung von Jungtieren (Fitness) oder der allostatischen Belastung (Physiologie) zwischen den exponierten und den nicht exponierten Clans feststellen. Dies deutet darauf hin, dass die Weidewirtschaft keine wesentlichen nachteiligen Auswirkungen auf die Tüpfelhyänen hatte. Diese Ergebnisse lassen darauf schließen, dass die Exposition gegenüber anthropogenen Aktivitäten mit dem Fortbestand gruppenlebender Großraubtiere vereinbar sein kann, wenn die räumlich-zeitliche Überlappung zwischen den wichtigsten Verhaltensweisen der Art und den anthropogenen Aktivitäten begrenzt ist. In Kapitel 4 schließlich zeige ich anhand von fäkalen DNA-Metabarkodierungen, dass die Tüpfelhyänenpopulation im Ngorongoro-Krater nicht regelmäßig vom Aussterben bedrohte Arten wie Spitzmaulnashörner (Diceros bicornis), fressen. Basierend auf DNA-Nachweisen von Massai-Giraffen (Giraffa camelopardalis tippelskirchi) und Haustieren in den Kotproben, zeige ich außerdem, dass Tüpfelhyänen zumindest gelegentlich den Krater zur Nahrungssuche verlassen. Darüber hinaus wurde ein positiver Zusammenhang zwischen dem Alter der Tupfelhyänen und der Neigung zum Verzehr von Haustieren festgestellt, was Hinweise zum für das Konfliktmanagement liefert. Diese Dissertation gibt Aufschluss über (i) die wichtigsten Variablen zur Verbesserung der lokalen Akzeptanz von Managementstrategien für Großraubtiere, (ii) die Auswirkungen anthropogener Aktivitäten auf den Fortpflanzungserfolg und Physiologie von Großraubtieren und (iii) die Art und Weise, wie Großraubtiere mit bedrohten Arten und lokalen Gemeinschaften in vielseitig genutzten Landschaften interagieren. Zusammenfassend sollte diese Dissertation wertvolles Wissen für die Optimierung des evidenzbasierten Großraubtierschutzes und die Koexistenz von lokalen Gemeinschaften und Raubtieren

Molecular Analyses of Changes Induced in the Microbial Populations of Murine Colon After As(III) Exposure

The gut microbiota is essential for mammalian health and metabolism. Thus identifying factors that influence the host microbiota is key to understanding the dynamic interplay between the host and its microbiota. Recent studies have shown the effect of chronic exposures of trivalent arsenic [As(III)] in environmentally relevant concentrations on host physiology, however, little is known of how it impacts the gut microbiota. This study examined the hypothesis that environmentally relevant concentrations of As(III) in drinking water will directly affect the murine colon microbial composition and physiology. The colon microbial communities from 10 and 250 ppb of As(III) exposed mice were compared to the control mice after 2, 5 and 10 weeks of As(III) exposure. Molecular analysis based on 16S rRNA gene and 16S- 23S intergenic region indicated a time and dose dependent shift in microbial community composition. Analysis of 16S rDNA clone libraries demonstrated an increase in Bacteroidetes and proportionally fewer Firmicutes in colon microbiota in response to As(III) exposure. Microbes have developed mechanisms to tolerate arsenic present in the environment. This study is the first to show that the gut microbes express arsenic resistant genes (arsA and arsB) in the colon. However, exposure to ppb concentrations of As(III) did not induce the expression of these genes in colon microbes. These data suggest that the selective effect of As(III) on colon microbiota was not due to direct exposure of colon microbes to As(III), but rather a response to changes in the host physiology. Since arsenic affects the NO levels in human cell lines, it was hypothesized that As(III) will affect the pathways that are linked to NO levels in human body. Many microbes present in human body have nitrogen metabolizing genes (nrfA) that contribute to NO levels, thus the expression levels of nrfA gene in colon microbes was examined. Real time RT-qPCR studies showed a time and dose dependent increase in nrfA expression in response to As(III) exposure. Together, the results presented in this study demonstrated an indirect effect of As(III) on the composition and physiology of murine colon microbiota that may further impact the host health

Spectral Tur\'an problems for intersecting even cycles

Let $C_{2k_1, 2k_2, \ldots, 2k_t}$ denote the graph obtained by intersecting $t$ distinct even cycles $C_{2k_1}, C_{2k_2}, \ldots, C_{2k_t}$ at a unique vertex. In this paper, we determine the unique graphs with maximum adjacency spectral radius among all graphs on $n$ vertices that do not contain any $C_{2k_1, 2k_2, \ldots, 2k_t}$ as a subgraph, for $n$ sufficiently large. When one of the constituent even cycles is a $C_4$, our results improve upper bounds on the Tur\'an numbers for intersecting even cycles that follow from more general results of F\"{u}redi [20] and Alon, Krivelevich and Sudakov [1]. Our results may be seen as extensions of previous results for spectral Tur\'an problems on forbidden even cycles $C_{2k}, k\ge 2$ (see [8, 34, 44, 45])

Steviol Glycosides and their use in food processing: A review

Steviol glycosides are the proteinacious secondary metabolites present in the leaves of Stevia rebaudiana Bertoni. These SG's are the principal sweetening agents which are 200-300 times more sweeter than sucrose. A number of SG's are present in the leaves of Stevia namely, stevioside, dulcoside A, rebaudioside A, rebaudioside B,  rebaudioside C (previously known as dulcoside B),  rebaudioside D, rebaudioside E and steviolbioside, 100–125. At the 63rd meeting a temporary ADI of 0-2 mg/kg bodyweight and day, expressed as steviol, was established based on a No-Observed-Effect-Level (NOEL). Steviol glycoside extracts have broad applications as sweetener in the manufacture of fruit and milk drinks, desserts, yoghurt, delicacies, confectioneries, fruit products, processed seafood products, pickles, table-top  sweeteners and dietary supplements. Other aspects considered are physicochemical and biologic properties for food processing, stability and therapeutic value of SG's. nutritional information, Stevia market and household uses.Â

Cathepsin-Sensitive Nanoscale Drug Delivery Systems for Cancer Therapy and other Diseases

International audienc

Physico-chemical analysis of low calorie high protein shrikhand prepared using stevia leaf powder

In the present study the textural properties of shrikhand along with the chemical properties were investigated. Based on the preliminary trial sugar was substituted with different ratios of stevia powder. Shrikhand prepared with Stevia powder showed a significant (P≤0.05) increase in the proximate composition of shrikhand. The textural parameters decreased with decrease in the amount of sugar significantly (P≤0.05).Keywords: Shrikhand, Stevia powder, Nutritive value, textur

A study of clinico-epidemiological profile of patients of snake bite and their outcome in a tertiary care centre in central zone of Himachal Pradesh

Background: The aim of this study was to assess clinico-epidemiological profile, prevalent treatment practices and outcome of snake bite patients in a tertiary care hospital in a hilly North central region of Himachal Pradesh. Methods: A hospital record based retrospective descriptive study was done which included demographic data, clinical profile, prevalent traditional treatment methods of snake bite, treatment given at hospital and outcome among 144 patients. Results: The 123 (83%) patients were young (age group of 17-50 years) and number of female patients was 89 (62%), 29 (38%) more than male patients. Most of snake bite cases recorded, presented in the months of July to September 56 (72.7%). The most frequently bitten sites were the upper limbs particularly left hand. 61 (42%) of patients presented without any features of envenomation. Hematotoxicity was the commonest presentation in 68 (82%) of patients followed by neuroparalysis in 26 (18%) of the symptomatic cases. Green snake (Green pit viper) was the commonest snake seen. Cure rate in our study was more than 80%. Major reason for delayed presentation was consultation of traditional healers. Conclusions: In the tropics and subtropics, snake bite is a life threatening health hazard especially in poor rural people who usually waste precious time by indulging in harmful activities. This needs public as well as health care workers’ awareness and prompt intervention in a health care facility.