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Circulating bile acids and HOMA-IR: cross-sectional results from the RoCAV population-based study
Full text linkBackground: Circulating bile acids (cBAs) function as signaling molecules that activate the farnesoid X receptor (FXR), promoting the secretion of fibroblast growth factor 19 (FGF-19), a gut-derived hormone involved in bile acid (BA) synthesis, glucose metabolism, and insulin sensitivity. However, the relationship between fasting cBAs, FGF-19, and insulin resistance-as estimated by HOMA-IR-remains unclear. This study explored these associations in an elderly population from Northern Italy. Material and methods: We examined a subsample of 1080 subjects (aged 60-75 years, 1:1 male-to-female ratio) from the RoCAV population-based study (2013-2016). Fasting blood samples were analyzed for 33 cBAs using UHPLC-MS/MS, of which 23 met quality criteria. FGF-19 levels were also measured. After excluding individuals with missing data or fibrate therapy, 1049 participants were included. Associations between cBAs, FGF-19, and HOMA-IR were assessed via linear regression, adjusting for age, sex, BMI, diet, alcohol intake, hypertension, and dyslipidemia. ROC curve analysis evaluated the ability of cBAs and FGF-19 to discriminate T2DM cases. Results: After excluding participants with missing anthropometric and clinical data or in fibrate treatment, data from 1049 subjects (mean±SD age 68.6±4.5 years, males 49.5%, T2DM 10.6%) were analysed. FGF-19 showed a positive correlation with primary cBAs (Spearman's ρ=0.33, p<0.001). Adjusted for covariates, both primary and secondary cBAs were positively associated with HOMA-IR (β=0.07, p=5×10-5; β=0.9, p=4×10-7) while FGF-19 was not (β=-0.02, p=0.31). In the mutually-adjusted model - including primary and secondary cBAs, FGF-19, and covariates - the β coefficients for cBAs were attenuated but remained significant (primary: β=0.06, p=0.005; secondary: β=0.07, p=0.0003), and FGF-19 retained an inverse association (β=-0.05, p=0.009). When total cBAs were used in the FGF-19-adjusted model, the association with HOMA-IR was the strongest (β=0.19, p=5×10-19). ROC curve analysis indicated that the inclusion of primary and secondary cBAs and FGF-19 improved model discrimination for T2DM (ΔAUC=0.03, 95% Confidence Interval: 0.01-0.06; Net Reclassification Improvement=0.54; 95%CI: 0.30-0.75). Conclusions: In this elderly Italian population, primary and secondary cBAs were positively associated with insulin resistance, after adjusting for each other, whereas FGF-19 negatively. These markers may enhance T2DM risk stratification and may give insights on bile acid-glucose metabolism links
Acido fumarico e fermentazione alcolica
No full textL’impatto dell’aggiunta di acido fumarico sull’attività di un pool di ceppi commerciali di S. cerevisiae e dei più diffusi non-Saccharomyces di interesse enologic
Molecular diversity patterns and introgression in alpine and Northern European populations of Arctic charr (Salvelinus alpinus)
Full text linkThe origin of Arctic charr populations in the lakes of the Italian Alps is not well understood. While some studies have suggested that they are postglacial relics, others have proposed that these populations are the result of intentional stocking efforts dating back to the sixteenth century. Subsequent introductions of Arctic charr to these lakes have made it difficult to untangle the evolutionary history of these Alpine populations. In this study, we examined the distribution of genetic variation among Arctic charr collected throughout their Northern and Southern European ranges at the beginning of the twenty-first century, using nuclear (amplified fragment length polymorphisms) and mitochondrial (control region and cytochrome oxidase I) loci. These analyses revealed the impact of restocking activities, which have resulted in admixture and hybridisation with Brook charr (Salvelinus fontinalis) in Italian alpine lakes and provides clues on the native or pseudo-native origin of Trentino-Alto Adige populations. The lack of detailed historical information, however, makes it difficult to disentangle the postglacial history of the species and to determine how much of the current diversity pattern can be ascribed to the consequences of Pleistocene events or anthropogenic activitie
State of the spread of the exotic parasitoid wasp Leptopilina japonica tracking the route of its invasive host fly Drosophila suzukii in France
No full textThe spotted-wing drosophila, Drosophila suzukii, is one of the most damaging invasive fruit pests in the world. It infests a wide range of wild and crop host plants, impacting natural habitats and causing significant economic losses. Leptopilina japonica, a predominant larval parasitoid of D. suzukii in the native areas of the fly, is now spontaneously expanding into non-native areas of its fly host. This study documents the presence and genetic structure of L. japonica collected from various wild and cultivated fruits across 11 sites in France in 2023. Leptopilina japonica emerged from 15% of fruit samples and was strongly positively associated with D. suzukii, showing parasitism rates up to 38.5%, notably in Lonicera fruits. Despite this, D. suzukii remained dominant, indicating a limited current biocontrol effect, while native parasitoids were nearly absent from samples. Molecular analyses using COI markers revealed 10 distinct haplotypes of the L. japonica subspecies in France that clustered into three groups, suggesting multiple introductions and/or migration routes into France from Asia, North America, and neighboring European countries. The lack of nuclear diversity measured from ITS2 markers suggests that the colonization is recent and that the populations experienced a bottleneck process. Nevertheless, a more extensive sampling combined with the use of additional genetic markers would be needed to better understand the origin and spread of L. japonica and its consequence on the equilibrium of Drosophila communitie
Morphological vs genomic approaches for studying subfossil diatoms in a high-altitude Alpine lake: pros and cons
No full textThanks to the continuous improvement of the High-Throughput Sequencing (HTS) techniques, the metabarcoding of eukaryotic organisms is being increasingly applied in surveys of freshwater microalgae including diatoms, which are among the most powerful and studied freshwater biological indicators. The metabarcoding approach for diatom studies is considered as highly promising since, in comparison to the classical morphological approach, it allows the simultaneous and cheap processing of large numbers of samples and does not need highly specialised taxonomical skills for the analyses of the results. Consequently, the metabarcoding approach has been recently applied also to the study of subfossil diatoms preserved in deep lake sediments aiming at reconstructing past environmental and ecological evolution at secular to millennial scale of temperate lakes. Here we compare the overall performance of a study, based on both metabarcoding and morphological approaches, of subfossil diatoms preserved in the deep sediments of a high-altitude lake: L. Marmotte, located at 2704 m a.s.l. within the Stelvio National Park in the Italian Central Alps. Shor cores were collected from the deepest point of the lakes in August 2017, radiometrically dated and analysed for a set of lithological, geochemical and biological proxies, including diatoms. A rapid degradation after sedimentation of total eDNA was observed, likely in relation to the aggressive physical lake settings, e.g. strong UV radiation and scorching effect along the lake banks related to the long winter ice cover. Therefore, the metagenomic approach was viable for samples not older than ca. 150 years. The classical morphological approach, although underestimating the abundance of the largest diatom taxa, provided more conservative results, thanks to good valvae preservation in the sediments under low water temperatures and acidic pH. In addition, the metabarcoding failed in assigning many small or recently defined/revised genera (e.g., Psammothidium, Adlafia, Genkalia, Sellaphora), as well as sporadic taxa (e.g., Eunotia, Cymbopleura), while it was more reliable than light microscopy in revealing the largest taxa belonging to Surirella, Neidium, Pinnularia. The metabarcoding appeared to overestimate the temporal changes in diatom taxonomic composition and diversity, while the morphological approach provided a more realistic picture of diatom temporal changes. The metabarcoding approach applied to less studied, remote high mountain lakes characterised by aggressive environmental settings appears reliable for general surveys of diatom diversity and changes at medium temporal scale (decades), while detailed ecological studies at secular to millennial scale largely benefit from the classical morphological approach. The improvement of the capacity for genus and species assignment of the diatom metabarcoding appears as crucial to improve a synergic complementarity with the classical morphological approach
Remote sensing reveals scale‐specific effects of forage crop mowing and landscape structure on a declining farmland bird
Full text linkThe effectiveness of agri-environment schemes (AESs), the largest conservation-related expenditure for farmland biodiversity conservation within the European Union, is often compromised by a limited spatial scale of implementation. We focused on multiannual forage crops, a surrogate habitat for grassland birds, to assess the scale-dependent effects of mowing timing and frequency on the local population size of an iconic species, the skylark (Alauda arvensis). While there is much evidence for a negative impact of in-field mowing activities on grassland birds, whether such effects occur also at broader spatial scales is largely unknown. We surveyed breeding skylarks in the Po Plain (northern Italy) to determine (1) the association between landscape composition/configuration and abundance and (2) how abundance is affected by forage crop mowing timing and frequency. We addressed both questions through scale optimisation, identifying the most influential spatial scales for each covariate. Forage crop mowing timing was assessed through a novel remote sensing algorithm based on high-resolution Sentinel-2 satellite images. We observed a strong scale dependence on the importance of different habitats in determining skylark abundance. Abundance increased with an increasing cover of forage crops locally (200 m) and of winter crops at a landscape scale (2600 m), suggesting that the species is favoured by heterogeneous agroecosystems. Locally (150–350 m), skylarks were more abundant when crops were aggregated, being negatively impacted by crop fragmentation caused by urbanization and by seminatural habitats. At the landscape scale (1150 m), the timing of mowing was consistent across years, with early-mown areas supporting fewer skylarks. This is probably because, over longer temporal scales, early-mown forage patches have limited or null productivity, eventually limiting local population size. Synthesis and applications. We provide a new perspective on the overarching influence of spatial scale in driving the abundance of a declining farmland bird species, supporting the urgency of designing landscape scale-effective AESs. This should be framed within the new EU Common Agricultural Policy reform and operated by farmer collectives, whereby management interventions should be monitored by state-of-the-art remote sensing techniques. These results suggest that implementing scale-optimized AESs could be crucial for effective farmland biodiversity conservatio
Candidate gene transcriptional signature unravels the reprogramming occurring in the peel of apple fruit of ‘Granny smith’ during postharvest storage
Full text linkAfter harvest fruit are stored to preserve the quality features established during the on-tree development and maturation, ensuring thus a continuous availability of fresh fruit on the market. For certain fruit species like apple, storage can last for almost a year, especially when coupled with several strategies, such as the reduction of the oxygen concentration or the application of ethylene competitor molecules, like 1-methylcyclopropene (1-MCP). To guarantee the maintenance of the highest quality, the monitoring of the physiological processes ongoing during the postharvest ripening is compelling. For this purpose, 16 genes belonging to key fruit ripening pathways, such as the ethylene and the sugar/fermentation metabolism, have been chosen as potential markers for the molecular characterization of the major changes occurring in the fruit during storage. Among these genes, ACS, PPO, PG1, RAP2-like, and ADH exhibited the most significant differential expression across the various samples. Based on the transcriptional pattern, this set of genes constitutes a valuable molecular tool for a precise and reliable RNA-based monitoring of the postharvest ripening progression and fermentation process in apples. PPO, together with S6PDH, were furthermore employed to inspect the onset of the superficial scald in apple and resulted to correlate with the evaluation of the incidence of this disorder and the accumulation of the sugar alcohol sorbitol, known to play important protecting roles to chilling injuries. The assessment of the transcriptional signature of these elements can facilitate the development of gene expression markers suitable for a more informed investigation of the physiological progression of the postharvest ripening in apples, ultimately leading to the promotion of high-quality stored apples, extending storage time while minimizing postharvest disorders and fruit los
Influence of egg sacs on the swimming performance of freshwater cyclopoid copepods
No full textFemale cyclopoid copepods carry their embryos in egg sacs that impact swimming performance until nauplii hatch. We studied kinematic parameters and mechanical energy of small routine jumps and large escape jumps of non-egg-carrying (NEC) and egg-carrying (EC) females of Mesocyclops leuckarti and Macrocyclops albidus. The drag and body acceleration costs for EC females of M. leuckarti and M. albidus during routine jumps were 28 and 40%, respectively, higher than those for NEC females moving at the same speed. Maintaining position in the water column by small jumps was more costly for EC females, requiring 2.2–2.3 times more jumps and energy. Consequently, the persistence of EC females was limited in the open water. In M. leuckarti and M. albidus, the average speed and distances of jumps were 5–6 and 1.5–2.2 times higher, respectively, and the duration of jumps was 2.2–2.5 times shorter during escape than routine swimming. The maximum jumping speeds of NEC females, 40.6 and 50.5 cm s−1, respectively, were 12–14% higher than those of EC females, whereas their power and cost of transport were 16 and 23% lower, respectively. These results clearly indicated that egg sacs impair swimming and increase energetic costs of movemen
Forest practitioners’ requirements for remote sensing-based canopy height, wood-volume, tree species, and disturbance products
No full textDespite decades of development, the uptake of remote sensing-based information products in the forestry sector is still lagging behind in central and southern Europe. This may partly relate to a mismatch of the developed remote sensing products and the requirements of potential users. Here, we present the results of a questionnaire survey in which we questioned 355 forest practitioners from eight central and southern European countries. We aimed to learn about forest practitioners' technical requirements for four remote sensing-based information products, including information on tree species, canopy height, wood volume/biomass, and forest disturbances. We asked for practitioners’ preferences with respect to thematic and spatial detail as well as the maximal acceptable error and the temporal frequency with which the information layers would be needed. We then examined whether the education, age, and professional background affect the requirements. Preferences with respect to spatial and thematic detail were comparably diverse while more homogenous patterns could be observed for demands with respect to errors and temporal frequency. Our results indicate that for some information products such as canopy height maps, existing remote sensing technology, and workflows can match all demands of practitioners. Remotely sensed information on forest disturbances partly fulfils the demands of the practitioners while for products related to tree species and wood volume/biomass the level of thematic detail and the accuracy of the products demanded by practitioners in central and southern Europe is not yet fully matched. We found no statistically significant differences between the demographic groups examined. The findings of this study improve our understanding of matches and mismatches of the technical requirements of practitioners for remote sensing-based information product
Effects of fertility control on the movement ecology of white-tailed deer
Full text linkThis doctoral thesis explores the effects of fertility control on the movement ecology of white-tailed deer (Odocoileus virginianus Zimmermann). Deer populations may become abundant in humandominated landscapes, taking advantage of anthropogenic resources and the lack of natural predators. This abundance poses increasing ecological, economic, and social challenges globally. As human activities expand, conflicts between deer populations and human interests intensify, manifesting in issues such as deer-vehicle collisions (DVCs), the spread of tick-borne illnesses, and habitat degradation. While traditional population control methods, such as controlled hunting, have proven effective, they are often impractical in suburban and urban settings. Non-lethal fertility control methods, including vasectomy, ovariectomy, and immunocontraceptive vaccines, present alternative solutions that may circumvent the need for lethal management. However, these methods induce physiological changes that may alter movement behavior. This thesis aims to bridge the knowledge gap concerning how fertility control interventions impact the movement behavior of white-tailed deer. Chapter 2 lays the groundwork by addressing a critical methodological issue often overlooked in studies of ecological movement responses — specifically, the relationship between mean speeds and diffusion rates using continuous-time speed and distance estimation techniques. Accurate modeling of an animal’s speed and distance traveled can be critical for interpreting behavior, yet ecological data often are too coarse, or the location error is too great to resolve these measures. Diffusion rates, in contrast, can be estimated using continuous-time models at even coarser sampling intervals. To examine this relationship, a regression analysis was conducted to estimate the correlation between mean speed and diffusion rate, accounting for uncertainties in both variables. Results indicated a strong, sublinear correlation between mean speed and diffusion rate, with a 1% increase in diffusion rate in my focal species predicting a 0.40% increase in mean speed (99% CI: 0.38–0.42%). Sampling intervals were progressively coarsened to assess the robustness of these estimates, and simulations were run using known true values to further evaluate the relationships. Across all sampling intervals, diffusion rates consistently remained substantially more accurate and precise than mean speed estimates, even when speed estimation was not possible. These findings establish diffusion rates as a more reliable and robust metric for linking movement to behavior across a wider range of datasets, thereby providing a foundation for the subsequent analyses of fertility control effects on deer movement in Chapters 3 and 4. Chapter 3 evaluates the effects of a large-scale vasectomy program on the movement behavior and activity of free-ranging white-tailed deer. This study leverages an existing fertility control program implemented on Staten Island, New York, USA, where vasectomies were performed on over 97% of antlered males, resulting in a dramatic reduction in fawning (approximately 95%). This intervention effectively left most female deer unbred, leading to multiple estrous cycles throughout the breeding season. Concerns have been raised that the additional estrus periods may extend breeding activity, potentially leading to decreased body condition and increased incidence of DVCs. To investigate these potential consequences, biologging devices were deployed on a total of 158 deer, across two sites: the treatment site on Staten Island and a control site at Rockefeller State Park Preserve in Pleasantville, NY, USA. The dataset included global positioning system (GPS) and accelerometry data from 84 females and 40 males. Advanced analytical methods, including continuous-time movement models and Hierarchical Generalized Additive Models (HGAMs), were applied to assess deviations in space use, movement patterns, and activity levels between treated and untreated groups. The results indicate that, contrary to initial concerns, the vasectomy program did not induce behavioral or social changes likely to negatively affect population health or safety during the study period. Chapter 4 investigates the effects of ovariectomy, an alternative fertility control method, on female white-tailed deer movement behavior. Ovariectomy induces anestrus, thereby preventing treated females from entering estrus, and eliminating estrous cycles and associated behaviors. Concerns have been raised that the absence of reproductive behavior could lead to altered movement patterns that might negatively impact body condition or increase the likelihood of DVCs. This chapter employs a treatment-control design using IoT-based telemetry data from 20 free-ranging female deer who were part of a management program in South Euclid, Ohio, USA. Ten individuals had undergone ovariectomy, while the remaining ten served as untreated controls. To assess the impact of ovariectomy on movement ecology, a 7-day moving window approach was applied to analyze diffusion rates, home-range size, and excursivity. Consistent with the findings from Chapter 3, the analysis revealed no significant differences in movement behavior between the treated and control groups, suggesting that ovariectomy does not introduce behavioral risks that would exacerbate management concerns. The findings from this thesis provide substantial evidence that fertility control methods, specifically vasectomy and ovariectomy, do not induce significant changes in the movement behavior of whitetailed deer at the time scales investigated. These results support the viability of non-lethal fertility control as a management strategy for addressing abundant deer populations in urban and suburban environments. By ensuring that such methods do not lead to unintended behavioral consequences, this work contributes to the development of new approaches to wildlife management in human dominated landscape