279 research outputs found
Exploring copepod distribution patterns at three nested spatial scales in a spring system. Habitat partitioning and potential for hydrological bioindication
In groundwater-fed springs, habitat characteristics are primarily determined by a complex combination of geomorphic features
and physico-chemical parameters, while species assemblages are even more intricate. Springs host species either inhabiting the spring
mouth, or colonizing spring habitats from the surface or from the aquifers which feed the springs. Groundwater species living in springs
have been claimed as good candidates for identifying dual aquifer flowpaths or changes in groundwater pathways before reaching the
spring outlets. However, the reliability of spring species as hydrological biotracers has not been widely investigated so far. Our study
was aimed at analysing a large karstic spring system at three nested spatial scales in order: i) to assess, at whole spring system scale,
the presence of a groundwater divide separating two aquifers feeding two spring units within a single spring system, by combining
isotope analyses, physico-chemistry, and copepod distribution patterns; ii) to test, at vertical spring system scale, the effectiveness of
copepods in discriminating surface and subsurface habitat patches within the complex mosaic spring environment; iii) to explore, at
local spring unit level, the relative role of hydrochemistry and sediment texture as describers of copepod distribution among microhabitats.
The results obtained demonstrated the presence of a hierarchical spatial structure, interestingly reflected in significant differences
in assemblage compositions. Copepod assemblages differed between the two contiguous spring units, which were clearly characterized
by their hydrochemistry and by significant differences in the groundwater flowpaths and recharge areas, as derived by the isotope
analyses. The biological results suggested that stygobiotic species seem to be related to the origin of groundwater, suggesting their potential
role as hydrological biotracers. At vertical scale, assemblage composition in surface and subsurface habitats was significantly
different, both between spring units and among microhabitats, supporting strong habitat preferences of copepod species. At the smaller
local scale, the response to habitat patchiness of subsurface copepod assemblages resulted in distribution patterns primarily defined
by sediment texture, while the sensitivity to differences in hydrochemistry was negligible
Diversity and Distribution of the Inland Water Decapods of Sicily (Crustacea, Malacostraca)
The current knowledge of Sicilian inland water decapod malacostracans is scarce and an updated synopsis on species distribution is lacking. Therefore, we reviewed the checklist and recent distribution of Sicilian inland water decapods based on published and unpublished records and novel observations with the aim of providing an exhaustive repository, also to be used as a sound baseline for future surveys. Overall, five native decapod species occur in the study area, i.e., the atyid shrimp Atyaephyra desmarestii, the palaemonid shrimps Palaemon adspersus, P. antennarius, and P. elegans, and the freshwater crab Potamon fluviatile, and their current local distributions are described. In addition, three alien species were recorded: the common yabby Cherax destructor and the red swamp crayfish Procambarus clarkii, strictly linked to inland waters, and the Atlantic blue crab Callinectes sapidus, a mainly marine species that can also colonise the lower stretches of rivers and coastal brackish waters. The collected data suggest the existence of a partial segregation of native versus non-native species, with the latter currently confined to coastal water bodies and the lower stretches of rivers. Moreover, the exclusively freshwater caridean A. desmarestii and P. antennarius show a parapatric distribution in the study area, which may suggest the existence of mutual exclusion phenomena. The results obtained raise some concerns about the effects of alien species on the native biota, and dedicated monitoring and management strategies should be implemented in order to better understand and mitigate their impact
Studies on the Toxicity and Efficacy of a New Amino Acid Solution in Pediatric Parenteral Nutrition
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142223/1/jpen0368.pd
Ecosistemi di acque interne e di transizione
In questo contributo la vulnerabilità degli ecosistemi acquatici ai cambiamenti climatici è analizzata in relazione ai meccanismi di organizzazione e mantenimento della biodiversità e dei processi ecosistemici. Dai processi degli ecosistemi derivano funzioni che forniscono una serie di benefici o servizi per il genere umano (Daily et al., 2009). Tali servizi sono in larga misura
dipendenti dalle componenti biologiche degli ecosistemi86. Negli ecosistemi acquatici i processi biogeochimici (ad es. denitrificazione batterica e assimilazione da parte della vegetazione acquatica), garantiscono l’abbattimento dei nutrienti, una funzione ecosistemica che produce il servizio di depurazione dell’acqua. Altri servizi sono la laminazione delle piene, la ricarica degli acquiferi, la regolazione del microclima locale, la produzione di risorse alimentari quali pesci, crostacei, ecc. (Jones, 2013). Le alterazioni degli ecosistemi, in particolare la perdita di specie e la diminuzione della biodiversità danneggiano questi servizi, con ricadute anche di tipo economico(si pensi, ad esempio, ai costi della depurazione dell’acqua destinata al consumo umano)
New distributional data for the Mediterranean medicinal leech Hirudo verbana Carena, 1820 (Hirudinea, Hirudinidae) in Italy, with a note on its feeding on amphibians
Scarce data are currently available about the distribution of the Mediterranean medicinal leech Hirudo verbana in Italy, and most of the known occurrence localities are based on records collected in the nineteenth and the first half of the twentieth century, which were not confirmed in the last decades, mostly due to a lack of surveys. Accordingly, the available knowledge on the distribution of the species is far from being updated and representative, although a significant negative trend of H. verbana throughout the country is supposed. The lack of sound distribution data is a significant shortfall, which hinders the implementation of the monitoring of the species as required by the Article 17 of the “Habitats Directive” on the species of Union concern. To provide recent, validated distributional data for the Mediterranean medicinal leech in Italy to be used as baseline data for further surveys and monitoring, we present herein a set of unpublished observations collected in the last decades in peninsular Italy, Sicily, and Sardinia. Moreover, we report observation of H. verbana feeding on amphibians, a feeding habit to date poorly documented for the Mediterranean medicinal leech. Based on both published and novel data, H. verbana is characterised by a large but fragmented distribution in Italy. Therefore, dedicated monitoring programs and the collection of validated occasional observations are highly desirable to get a clearer picture of the real distribution of the species
Advances in Glucocorticoid-Induced Osteoporosis
Glucocorticoid-induced osteoporosis (GIOP) is one of the most important side effects of glucocorticoid use, as it leads to an increased risk of fractures. Recently, many published studies have focused on the cellular and molecular mechanisms of bone metabolism, the pathophysiology of GIOP, and the intervention options to prevent GIOP. In this review, recent advances in GIOP are summarized, particularly recent progress in our understanding of the mechanisms of GIOP resulting in improved insight that might result in the development of new treatment options in the near future
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