2,129 research outputs found

    Global analysis of ecological niche conservation and niche shift in exotic populations of monkeyflowers (Mimulus guttatus, M. luteus) and their hybrid (M. x robertsii)

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    Background Hybridisation associated with biological invasions may generate new phenotypic combinations, allowing hybrids to occupy new ecological niches. To date, few studies have assessed niche shifts associated with hybridisation in recently introduced populations while simultaneously characterising the niche of parental species in both native and introduced ranges. Aims Here, we compared (1) the ecological niche of a novel hybrid monkeyflower, M. × robertsii, with the niches of its two parental taxa (M. guttatus, M. luteus), and (2) the ecological niches of native (Americas) and introduced parental populations (Europe and New Zealand). Methods We assembled >13,000 geo-referenced occurrence records and eight environmental variables and conducted an ecological niche model analysis using maximum entropy, principal component and niche dynamics analysis. Results We found no evidence of niche shift in the hybrid, which may result in potential competition between parental and derived taxa in the introduced range. M. guttatus showed niche conservatism in introduced populations in Europe, but a niche shift in New Zealand, while M. luteus showed a niche shift in Europe. Conclusions The comparison of native and non-native populations of parental taxa, suggests that whether invasions result in niche shifts or not depends on both taxon and geographic region, highlighting the idiosyncratic nature of biological invasions

    dynamAedes: a unified modelling framework for invasive Aedes mosquitoes

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    Mosquito species belonging to the genus Aedes have attracted the interest of scientists and public health officers because of their capacity to transmit viruses that affect humans. Some of these species were brought outside their native range by means of trade and tourism and then colonised new regions thanks to a unique combination of eco-physiological traits. Considering mosquito physiological and behavioural traits to understand and predict their population dynamics is thus a crucial step in developing strategies to mitigate the local densities of invasive Aedes populations. Here, we synthesised the life cycle of four invasive Aedes species (Ae. aegypti, Ae. albopictus, Ae. japonicus and Ae. koreicus) in a single multi-scale stochastic modelling framework which we coded in the R package dynamAedes. We designed a stage-based and time-discrete stochastic model driven by temperature, photo-period and inter-specific larval competition that can be applied to three different spatial scales: punctual, local and regional. These spatial scales consider different degrees of spatial complexity and data availability by accounting for both active and passive dispersal of mosquito species as well as for the heterogeneity of the input temperature data. Our overarching aim was to provide a flexible, open-source and user-friendly tool rooted in the most updated knowledge on the species’ biology which could be applied to the management of invasive Aedes populations as well as to more theoretical ecological inquirie

    A mixed-valence diruthenium(ii,iii) complex endowed with high stability: from experimental evidence to theoretical interpretation

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    We herein report the synthesis and multi-technique characterization of [Ru2Cl((2-phenylindol-3-yl)glyoxyl-l-leucine-l-phenylalanine)4], a novel diruthenium(ii,iii) complex obtained by reacting [Ru2(μ-O2CCH3)4Cl] with a dual indolylglyoxylyl dipeptide anticancer agent. We soon realised that the compound is very stable under several different conditions including aqueous buffers or organic solvents. It is also completely unreactive toward proteins. The high stability is also suggested by cellular experiments in a glioblastoma cell line. Indeed, while the parent ligand exerts high cytotoxic effects in the low μM range, the complex is completely non-cytotoxic against the same line, most probably because of the lack of ligand release. To investigate the reasons for such high stability, we carried out DFT calculations that are fully consistent with the experimental findings. The results highlight that the stability of [Ru2Cl((2-phenylindol-3-yl)glyoxyl-l-leucine-l-phenylalanine)4] relies on the nature of the ligand, including its steric hindrance that prevents the reaction of any nucleophilic group with the Ru2 core. Ligand displacement is the key step to allow reactivity with the biological targets of metal-based prodrugs. Accordingly, we discuss the implications of some important aspects that should be considered when active molecules are chosen as ligands for the synthesis of paddle-wheel-like complexes with medicinal applications. This journal i

    Quali strumenti giuridici statali e regionali per le comunit\ue0 patrimoniali?

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    The Framework Convention on the Value of Cultural Heritage for Society (Faro Convention, 2005) recognizes a central role to heritage communities in the process of identification, study, interpretation, protection, conservation and presentation of the cultural heritage. As a signatory State of the Convention (signed on 27th February 2013, still waiting for ratification), Italy has in any case to ensure its contribution to the safeguarding of the tangible and intangible cultural heritage by adequate policies. Currently, a State law providing a general regulation of the participation of civil society to the protection and the enhancement of cultural heritage in the Italian legal system has not been adopted yet. Nevertheless, communities, groups and individuals have a wide range of instruments available, which can be drawn by an accurate interpretation of the Constitution and of many State and regional laws. In the long run, the persistent lack of common rules on this subject may be a source of uncertainty, capable of weakening, instead of strengthening, the role of heritage communities, in contrast with the principles of the Faro Convention

    Shoulder pain due to cervical radiculopathy: an underestimated long-term complication of herpes zoster virus reactivation?

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    Purpose To evaluate if herpes zoster virus (HZV) reactivation may be considered in the aetiology of cervical radiculopathy. Methods The study group was composed of 110 patients (52 M-58F;mean age ± SD:46.5 ± 6.12; range:40-73) with a clinical diagnosis of cervical radiculopathy. Patients with signs of chronic damage on neurophysiological studies were submitted to an X-ray and to an MRI of the cervical spine in order to clarify the cause of the cervical radiculopathy and were investigated for a possible reactivation of HZV; HZV reactivation was considered as “recent” or “antique” if it occurs within or after 24 months from the onset of symptoms, respectively. Data were submitted to statistics. Results Thirty-eight patients (34,5%,16 M-22F) had a history of HZV reactivation: four (2 M-2F) were “recent” and 34 (14 M-20F) were “antique”. In 68 of 110 participants (61,8%,30 M-38F), pathological signs on X-ray and/or MRI of the cervical spine appeared; in the remaining 42 (38,2%,22 M-20F) X-ray and MRI resulted as negative. Among patients with HZV reactivation, seven (18,4%) had a “positive” X-ray-MRI while in 31 (81,6%) the instrumental exams were considered as negative. The prevalence of “antique” HZV reactivations was statistically greater in the group of patients with no pathological signs on X-ray/MRI of the cervical spine with respect to the group with a pathological instrumental exam (p < 0.01). Conclusions It may be useful to investigate the presence of a positive history of HZV reactivation and to consider it as a long-term complication of a cervical root inflammation especially in patients in which X-ray and MRI of the cervical spine did not show pathological findings

    Citizens of Europe

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    Il titolo della collana esprime la volont\ue0 di approfondire i profili legati al processo di integrazione europeo, non ignorandone i risvolti pi\uf9 discutibili e burocratici ma sapendo guardare al di l\ue0 di essi, nella logica che traspare dal gioco di assonanze indicato dal titolo. In questo terzo volume Citizens of Europe, dedicato ai temi delle identit\ue0 e della cittadinanza culturale, viene in rilievo la tensione tra i limiti delle politiche, culturali e di cittadinanza, perseguite dalla UE e l\u2019imporsi progressivo \u2013 malgrado le cupe ombre proiettate dalla drammatica attualit\ue0 \u2013 di una pi\uf9 ampia nozione di \u2018cittadinanza d\u2019Europa\u2019, scandita in particolare da quei recenti strumenti giuridici del Consiglio d\u2019Europa attraverso i quali l\u2019afflato europeo, non imprigionato nelle pastoie dei meccanismi della EU citizenship, si sviluppa pi\uf9 significativamente

    Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

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    Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated

    Drivers of habitat availability for terrestrial mammals: Unravelling the role of livestock, land conversion and intrinsic traits in the past 50 years

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    The global decline of terrestrial species is largely due to the degradation, loss and fragmentation of their habitats. The conversion of natural ecosystems for cropland, rangeland, forest products and human infrastructure are the primary causes of habitat deterioration. Due to the paucity of data on the past distribution of species and the scarcity of fine-scale habitat conversion maps, however, accurate assessment of the recent effects of habitat degradation, loss and fragmentation on the range of mammals has been near impossible. We aim to assess the proportions of available habitat within the lost and retained parts of mammals' distribution ranges, and to identify the drivers of habitat availability. We produced distribution maps for 475 terrestrial mammals for the range they occupied 50 years ago and compared them to current range maps. We then calculated the differences in the percentage of 'area of habitat' (habitat available to a species within its range) between the lost and retained range areas. Finally, we ran generalized linear mixed models to identify which variables were more influential in determining habitat availability in the lost and retained parts of the distribution ranges. We found that 59% of species had a lower proportion of available habitat in the lost range compared to the retained range, thus hypothesizing that habitat loss could have contributed to range declines. The most important factors negatively affecting habitat availability were the conversion of land to rangeland and high density of livestock. Significant intrinsic traits were those related to reproductive timing and output, habitat breadth and medium body size. Our findings emphasize the importance of implementing conservation strategies to mitigate the impacts caused by human activities on the habitats of mammals, and offer evidence indicating which species have the potential to reoccupy portions of their former range if other threats cease to occur.This study investigates the impact of habitat degradation on terrestrial mammal species. By comparing historic and current distribution maps for 475 species, we found that 59% of them have less available habitat in their lost ranges, suggesting habitat loss contributed to range declines. Factors like land conversion to rangeland and high livestock density negatively affected habitat availability. Intrinsic traits such as reproductive timing, habitat breadth and medium body size also played a role. The study underscores the need for conservation efforts to mitigate human-induced habitat threats and identifies species that could potentially reclaim lost range if threats are addressed.imag

    The Collagen Chaperone HSP47 Is a New Interactor of APP that Affects the Levels of Extracellular Beta-Amyloid Peptides

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    Alzheimer disease (AD) is a neurodegenerative disorder characterized by progressive decline of cognitive function that represents one of the most dramatic medical challenges for the aging population. Aβ peptides, generated by processing of the Amyloid Precursor Protein (APP), are thought to play a central role in the pathogenesis of AD. However, the network of physical and functional interactions that may affect their production and deposition is still poorly understood. The use of a bioinformatic approach based on human/mouse conserved coexpression allowed us to identify a group of genes that display an expression profile strongly correlated with APP. Among the most prominent candidates, we investigated whether the collagen chaperone HSP47 could be functionally correlated with APP. We found that HSP47 accumulates in amyloid deposits of two different mouse models and of some AD patients, is capable to physically interact with APP and can be relocalized by APP overexpression. Notably, we found that it is possible to reduce the levels of secreted Aβ peptides by reducing the expression of HSP47 or by interfering with its activity via chemical inhibitors. Our data unveil HSP47 as a new functional interactor of APP and imply it as a potential target for preventing the formation and/or growth amyloid plaques

    Remotely sensed spatial heterogeneity as an exploratory tool for taxonomic and functional diversity study

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    Assessing biodiversity from field-based data is difficult for a number of practical reasons: (i) establishing the total number of sampling units to be investigated and the sampling design (e.g. systematic, random, stratified) can be difficult; (ii) the choice of the sampling design can affect the results; and (iii) defining the focal population of interest can be challenging. Satellite remote sensing is one of the most cost-effective and comprehensive approaches to identify biodiversity hotspots and predict changes in species composition. This is because, in contrast to field-based methods, it allows for complete spatial coverages of the Earth's surface under study over a short period of time. Furthermore, satellite remote sensing provides repeated measures, thus making it possible to study temporal changes in biodiversity. While taxonomic diversity measures have long been established, problems arising from abundance related measures have not been yet disentangled. Moreover, little has been done to account for functional diversity besides taxonomic diversity measures. The aim of this manuscript is to propose robust measures of remotely sensed heterogeneity to perform exploratory analysis for the detection of hotspots of taxonomic and functional diversity of plant species
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