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Evidence for density-dependent effects on body composition of grizzly bears in a changing Greater Yellowstone Ecosystem
Get PDFThe Greater Yellowstone Ecosystem, although recognized as one of the world's least impacted temperate ecosystems, has undergone environmental alterations over the last decades. During this period of changes, concerted management efforts have allowed the grizzly bear population to increase significantly. As a result, the range and density of the bear population has also increased, despite a decline of some high-calorie foods. This study investigated the intraspecific processes driving bear population demography in the face of climatic and human impacts affecting the availability of some key food resources. We examined lean body mass and percent body fat from >400 grizzly bears over the two decades and in relation to a temporally and spatially explicit index of grizzly bear density, individual traits, and landscape zonation. Specifically, we hypothesized that individual lean body mass declined as population density increases, and that density had an age-dependent effect. Further, we hypothesized that individual body fat levels were independent from population density and environmental changes, as omnivory helped buffer energy intake from fluctuation in high-calorie food sources. We found that lean body mass was negatively related with grizzly bear population density, particularly in young females. Although higher densities had a more negative impact on female bears, they still reached their typical total body mass as they matured (>7 years of age), which may be due to delaying reproduction or moving to areas with fewer bears. In contrast, we found that percent body fat remained constant as grizzly bear population density increases, despite recent environmental changes, possibly by shifting feeding tactics. Our study shows that individual Yellowstone grizzly bear performance is influenced more by intraspecific competition than landscape-level food changes, highlighting a notable resilience of grizzly bear to environmental alterations
Monitoring the volatilome of kefir and kefir-like cereal-based beverages during fermentation by PTR-Tof-MS
Get PDFThe role of automatic pollen and fungal spore monitoring across major end-user domains
Get PDFThe advent of automatic pollen and fungal spore monitoring over the past few years has brought about a paradigm change. The provision of real-time information at high temporal resolution opens the door to a wide range of improvements in terms of the products and services made available to a widening range of end-users and stakeholders. As technology and methods mature, it is essential to properly quantify the impact automatic monitoring has on the different end-user domains to better understand the real long-term benefits to society. In this paper, we focus the main domains where such impacts are expected, using Europe as a basis to provide qualitative estimates and to describe research needs to better quantify impacts in future. This will, in part, also serve to justify further investment and help to expand monitoring network
Gut microbiome dynamics in primates across a tropical ecosystem
No full textThe anthropogenic impact on tropical ecosystems has led to a significant loss of biological diversity, with non-human primates facing a high risk of extinction. According to the World Conservation Union (IUCN), almost one third of non-human primate species are classified as endangered, with the main driver being loss of preferred habitat and food resources. Habitat loss has inevitably affected the diet and gut microbiota of these species, leading to a loss of biological diversity at the microscopic level. The gut microbiota and its genome collection (gut microbiome) play an essential role in host health, performing functions such as digestion, fermentation of complex compounds, modulation of the immune system, and defense against external pathogens. Gut dysbiosis, due to the loss or acquisition of new microorganisms, is often associated with inflammation and disease. Research on the gut microbiota of wild animal species living in human-affected environments (e.g., deforestation) has shown losses in richness or changes in gut microbiota composition. However, deeper investigations into the functional significance of these losses are missing, and understanding the dynamics between host gut microorganisms and those of the surrounding environment would also elucidate the impact of human activities on host health. Using non-human primates as model species, this thesis aims to (i) describe the current understanding of gut symbiont dynamics and their consequences on host health; (ii) investigate the contribution of extrinsic and intrinsic factors to gut microbiota variation; and (iii) explore the impact of extrinsic factors on the microbiome and the resulting variations in host metabolic functions. Chapter 1: This review focuses on studies of the most abundant intestinal microorganisms (bacteria) in conjunction with other intestinal symbionts (fungi, archaea, helminths, and viruses) to understand their associations, interactions, and effects on host health. This chapter reviews the current understanding of interactions and associations between bacteria and various symbionts. It highlights how changes in some intestinal symbionts relative to others, as well as fluctuations among multiple symbionts due to intrinsic or extrinsic factors, can impact the host. These interactions and their effects are often complex and not easily understood. Chapter 2: Investigates the variation in gut microbiota (bacteria and fungi) of a population of yellow baboons (Papio cynocephalus) in relation to habitat type (extrinsic factor) and sex (intrinsic factor). The study observed that gut microbiota variations are affected by habitat type, with bacterial and fungal community diversity potentially mediated by sex, emphasizing the importance of combining biological and ecological factors in microbiota analyses. Chapter 3: Provides the first comprehensive identification of bacterial and fungal communities in the Sanje mangabey (Cercocebus sanjei), an endangered species endemic to the Udzungwa Mountains. The chapter explores the potential contamination of gut microorganisms by soil microorganisms, highlighting a significant transfer of soil saprotrophic fungal communities to the gut. This suggests an association between geophagy— a behavior of consuming soil observed in the Sanje mangabey—and its highly frugivorous diet. Geophagy is an adaptive behavior that may have various functions, such as relieving gastrointestinal stress. Our results suggest that these benefits may be partly determined by the presence of microorganisms in the soil and their interaction with the gut microbiome. Chapter 4: Investigates the diversity of metabolic functions of gut microorganisms in two non-human primate hosts, the Udzungwa red colobus (Piliocolobus gordonorum) and yellow baboons, using in-depth sequencing methods (metagenomics). The study found a strong association between observed metabolic functions and the distinct diets of the hosts. Differences in metabolic functions were also observed within the same host species living in contrasting habitat types, suggesting that specialized diets may be more affected by habitat differences than generalist diets. Overall, this thesis provides a comprehensive view of the complexity of gut microbial variations in terms of structure, composition, and metabolic functions. It emphasizes the importance of studying these variations in wild host species, which are often threatened by human activities. These findings can improve awareness in the field of conservation and aid in developing strategies to mitigate the effects of anthropogenic disturbanc
Combining algorithm techniques with mechanical and acoustic profiles for the prediction of apples sensory attributes
No full textThe research work shows the potentiality of advanced linear and nonlinear learning algorithm techniques in the prediction of apples texture sensory attributes as “hardness”, “crunchiness”, “flouriness”, “fibrousness”, and “graininess”. Starting from the information contained in the entire mechanical and acoustic curves acquired during samples compression test, the prediction performances of five different statistical tools as Partial Least Squares regression (PLS), Multilayer Perceptron (MLP), Support Vector Regression (SVR) and Gaussian Process Regression (GPR) are shown and discussed. All Predictive models validations evidence best accuracies for texture sensory attributes “hardness” and “crunchiness” and in general for GPR learning algorithm. By combining mechanical and acoustic profiles, 5-fold cross validations produce values of coefficient of determination R2 up to 0.885 (GPR) and 0.840 (GPR), respectively for “hardness” and “crunchiness”. These results, comparable to those obtained by considering a large number of mechanical and acoustic parameters extracted from acquired profiles as predictive factors, evidence a new and reliable way for the prediction of texture sensory attributes of apples. The proposed approach can overcome the necessity to define, in advance, number and type of features to be calculated from instrumental texture profiles and can be easily implemented in an automatic proces
Application of high-throughput sequencing for comprehensive virome profiling in grapevines shows yellows in Iran
Get PDFA comprehensive study on the whole spectrum of viruses and viroids in five Iranian grapevine cultivars was carried out using sRNA libraries prepared from phloem tissue. A comparison of two approaches to virus detection from sRNAome data indicated a significant difference in the results and performance of the aligners in viral genome reconstruction. The results showed a complex virome in terms of viral composition, abundance, and richness. Thirteen viruses and viroids were identified in five Iranian grapevine cultivars, among which the grapevine red blotch virus and grapevine satellite virus were detected for the first time in Iranian vineyards. Grapevine leafroll-associated virus 1 (GLRaV1) and grapevine fanleaf virus (GFLV) were highly dominant in the virome. However, their frequency and abundance were somewhat different among grapevine cultivars. The results revealed a mixed infection of GLRaV1/grapevine yellow speckle viroid 1 (GYSVd1) and GFLV/GYSVd1 in grapevines that exhibited yellows and vein banding. We also propose a threshold of 14% of complete reconstruction as an appropriate threshold for detection of grapevine viruses that can be used as indicators for reliable grapevine virome profiling or in quarantine stations and certification program
Factors influencing the performance of Ganaspis brasiliensis G1 in Northern Italy as part of a biological control project against Drosophila suzukii
Get PDFDrosophila suzukii, the spotted-wing drosophila (SWD), is a small fruit fly native to Southeast Asia. Its peculiar serrated ovipositor allows the female to lay eggs inside ripening undamaged fruit, particularly soft berries and stone fruits, causing huge damage. The life cycle is rapid, with multiple generations in a single growing season. Infestations lead to compromised fruit quality, reduced marketability, and economic losses for fruit growers. Managing SWD currently requires a combination of cultural, biological, and chemical control strategies to minimize its impact on fruit production. However, in invaded areas, classical biological control with specialized parasitoids coevolved in Asia can be the most effective and sustainable strategy, ensuring stable and long-lasting control. As a fact, by introducing native parasitoid wasps into affected areas, there is the potential to reduce the population of SWD reaching the natural ecological equilibrium between host and parasitoid and hence mitigate the damage caused by this invasive pest. Therefore, in Italy in 2021 a national biological control project was approved, involving the release of the most specialized and effective natural enemy of SWD, the larval parasitoid Ganaspis brasiliensis, Japanese strain G1, in many regions. After 3 years of field releases of G. brasiliensis, we are now committed to understanding its establishment capacity in the new environment and the ongoing multitrophic relationships with the host and other local and exotic biocontrol agents to better predict its spread, its SWD control capability, and, as a consequence, enhance the project outcomes. For these purposes, we performed field experiments exposing blueberries infested with D. suzukii larvae that had just been parasitized by G. brasiliensis in different natural environments. The aim was to evaluate the abiotic and biotic factors that influenced G. brasiliensis development. The data revealed that secondary infestations carried out by local drosophilids and secondary parasitization carried out by larval parasitoids, both autochthonous and exotic, resulted into a significant reduction of G. brasiliensis emerging adults. Moreover, emersion data demonstrated that Leptopilina sp. individuals were significantly faster to reach adulthood compared to G. brasiliensis. These data suggest that interspecific competition play an important role into regulate G. brasiliensis population in natural conditions in our release sites. We discuss the results obtained in relation to the potential implications, both positive and negative, regarding the achievement of the objectives set by the Italian project of classical biological control against SWD. Additionally, the collected data are valuable for optimizing the current methods of monitoring parasitoids and their effects in the field
