Skates are characterised by conservative body morphology which hampers identification and leads to frequent taxonomic confusion and market mislabelling. Accurate specimen classification is crucial ...for reliable stock assessments and effective conservation plans, otherwise the risk of extinction could be unnoticed. The misclassification issue is evident for the genus Dipturus, distributed worldwide, from the continental shelf and slope to the deep sea. In this study, barcode cytochrome oxidase I gene (COI) sequences were used along with species delimitation and specimen assignment methods to improve taxonomy and zoogeography of species of conservation interest inhabiting the Atlantic Ocean and Mediterranean Sea. In this study, we provided new evidence of the occurence of D. nidarosiensis in the Central‐Western Mediterranean Sea and the lack of Atlantic‐Mediterranean genetic divergence. The Atlantic endangered species D. laevis and D. batis clustered together under the same molecular operational taxonomic unit (MOTU) with any delimitation methods used, while the assignment approach correctly discriminated specimens into the two species. These results provided evidence that the presence of the barcode gap is not an essential predictor of identification success, but the use of different approaches is crucially needed for specimen classification, especially when threshold‐ or tree‐based methods result less powerful. The analyses also showed how different putative, vulnerable, species dwelling across South‐Western Atlantic and South‐Eastern Pacific are frequently misidentified in public sequence repositories. Our study emphasised the limits associated to public databases, highlighting the urgency to verify and implement the information deposited therein in order to guarantee accurate species identification and thus effective conservation measures for deep‐sea skates.
Accurate specimen classification is crucial for reliable stock assessments and effective conservation plans, otherwise the risk of extinction could be unnoticed. The misclassification issue is evident for a range of taxa, especially those with conserved body morphology, such as skates belonging to the genus Dipturus. The joint use of COI barcode‐based methods as species delimitation and specimen assignment approaches could improve the accuracy of specimen identification and help to build curate reference libraries. This study also emphasizes the limits associated to public databases, highlighting the urgency to verify, update and implement the information deposited therein in order to guarantee correct identification and thus effective species conservation measures.
This work focuses on the species associations of the Baronie Seamount (north-eastern Sardinia, Italy), according to variations in depth and time of day. The aim was to highlight the potential ...vertical movements of the species and to compare these results to existing data from a submarine canyon. Twenty-two samples were taken at different depths and times along two trawl lines over the seamount. A total of 94 species were caught; among these, 48 bony fish, 9 cartilaginous fish, 13 molluscs and 24 crustaceans were selected for analysis. Cluster analysis showed 3 groups in which both depth and time of day play an important role in grouping. Nine species showed some daily and nocturnal movement, probably linked to trophic requirements. The daily movements according to size and sex of the shrimps Aristaeomorpha foliacea and Aristeus antennatus were also studied. For these two populations, the analysis showed an uneven distribution and the diel cycle appears to involve only the females. These species seem to adapt their life cycle to the geomorphology of the sea bottom. The diurnal movements from the base of the seamount to the edge of the continental shelf increase the range of the species distribution. In fact, the seamount, due to its geomorphological conformation, offers these species the opportunity to very quickly span a considerable range of depths. These movements are known to occur in the continental shelf and slope, but in the seamount they are broadened and can be studied more easily.
A new class of lanthanide mixed‐carboxylate ligands compounds with formula {Ln2(phthgly)4(bdc)(H2O)6·(H2O)4}∞, labelled as Ln3+: Eu (1) and Gd (2) coordination polymers (CP) were synthesized under ...mild reaction conditions between lanthanide nitrate salts and a solution of N‐phthaloylglycine (phthgly) and terephthalic (bdc) ligands. The (1) and (2) coordination polymers were formed by symmetric binuclear units, in which phthgly and bdc carboxylate ligands are coordinated to the lanthanide ions by different coordination modes. Surprisingly, all organic ligands participate in hydrogen bonding interactions, forming an extremally rigid crystalline structure. The red narrow emission bands from the 5D0→7FJ transitions of the Eu3+ ion show a high colour purity. The intramolecular energy transfer process from L→Eu3+ ion has been discussed. The experimental intensity parameters (Ω2,4) reflect lower angular distortion and polarizability of the chemical environment around the metal ion compared with other Eu3+ compounds reported in the literature. This novel class of coordination polymer offers a more attractive platform for developing luminescent functional materials for different applications.
In this work we have studied the assemblages from Quirra canyon (Sardinia). We analysed data from 25 trawl samples from the canyon, made at different times and depth. A total of 71 demersal species ...(38 teleosts, 5 cartilaginous fishes, 13 molluscs and 15 crustaceans) were examined. We found four groups using cluster analysis; each group is characterised by a certain depth or time. In particular we have shown that the time of the day appears to have a role in the movement of shrimps and other species. This phenomenon seems to be linked to trophic need and by the consequent different food availability into the Canyon.
Faecal candida and diarrhoea Forbes, D; Ee, L; Camer-Pesci, P ...
Archives of disease in childhood,
04/2001, Volume:
84, Issue:
4
Journal Article
Peer reviewed
Open access
BACKGROUND Candida species are frequently isolated from stools of children with diarrhoea but are not proven enteropathogens. It is hypothesised that faecal candida causes diarrhoea. AIMS To ...determine the prevalence of faecal candida in childhood diarrhoea and the relation between faecal yeasts and diarrhoea. METHODS Comparison of clinical and laboratory data, including quantitative stool culture for yeasts from 107 children hospitalised with diarrhoea and 67 age matched controls without diarrhoea. RESULTS Yeast species, predominantly candida, were identified in the stools of 43 children (39%) with diarrhoea and 26 (36%) without diarrhoea. The concentration of candida was positively associated with recent antibiotic use (p = 0.03) and with the presence of another enteric pathogen (p < 0.005), but not with patient age, nutritional status, or duration of diarrhoea. CONCLUSION Candida species do not cause childhood diarrhoea in well nourished children.
This study presents a comprehensive investigation into the structural and luminescent properties of lanthanide 2-hydroxybenzoate compounds, focusing on Eu3+ and Tb3+ ions in both single and mixed ...systems. The X-ray structures of (Hphen)2Eu2(2-OHBz)8(H2O)2·2H2O (1a·2H2O) and Eu(2-OHBz)3(phen)2·PhMe (2a·PhMe) were determined, where 2-OHBz: 2-hydroxybenzoate and phen: 1,10-phenantroline, revealing triclinic crystal structures with distinct coordination geometries. Compound 1a·2H2O displayed a centrosymmetric dinuclear anion with a coordination number of eight for each Eu3+ center, while compound 2a·PhMe exhibited a neutral mononuclear complex with a decacoordinated Eu3+ center. A comparative analysis of luminescent properties between these compounds unveiled significant differences in the nonradiative decay rates of the 5D0 level of Eu3+ ions, suggesting potential luminescence-quenching channels. The investigation is extended to mixed Eu3+-Tb3+ systems, demonstrating efficient Tb3+ to Eu3+ energy transfer, especially at room temperature. Three models, including two novel ones proposed in this study, were considered to rationalize energy transfer in the mixed systems. Our theoretical-experimental investigation reveals that variations in lifetimes of the emitting level 5D0 of Eu-2-OHBz mononuclear and binuclear complexes, or mixed Eu/Tb-2-OHBz complexes, with 1,10-phenanthrolines, primarily result from multiphonon decay processes; however, low-energy ligand-to-metal charge transfer (LMCT) states play a key role in suppressing luminescence in the binuclear complex compare to the mononuclear ones.
The image depicts X-ray structures of (Hphen)2Eu2(2-OHBz)8(H2O)2·2H2O (1a) and Eu(2-OHBz)3(phen)2·PhMe (2a), sample photos with UV illumination, energy transfer processes, and a luminescence decay curve modeled with three different approaches. These models are used to rationalize the luminescent properties of mononuclear and binuclear Eu/Tb-2-hydroxybenzoate complexes with 1,10-phenanthroline. Display omitted
•Structural and luminescent properties of the mono and binuclear Eu/Tb-2-hydroxybenzoate complexes with 1,10-phenanthroline.•Luminescence activation and quenching of Eu3+ ions in mixed systems.•Novel models for understanding energy transfer and excited-state lifetimes in mixed lanthanide systems.
The aim of this study is to perform an analysis of the spectroscopic and electronic properties of three vanadium(IV) complexes formed from bis(acetylacetonato)oxovanadium(IV) VO(acac)2 and ...pyrid-2-one (2pyon) or pyrid-4-one (4pyon) ligands: VO(acac)2(2pyon) (1), VO(acac)2(4pyon) (2) and VO(acac)2(H2O)·4pyon (3). In 1 and 2, the pyridone ligand coordinates neutral and monodentate to the vanadium center, with the oxygen atom placed in the axial trans position to the oxo ligand. In 3, the 4pyon ligand remains outside the metal first coordination sphere but bound to the aqua ligand through hydrogen bonds that led to the formation of a supramolecular structure. Moreover, the Density Functional Theory (DFT) were applied to answer two overarching aspects. First, in complexes 1 and 2, the DFT analysis was used to establish the most stable configuration among the vanadium pyridone complex isomers, comparing the ligand via O-bound pyridone and N-bound hydroxypyridine chelating modes. Second, DFT was also performed to enable understanding of the intermolecular interactions between the 4pyon and the VO(acac)2(H2O) moiety to elucidate the intermolecular interactions in 3. Further insights were also obtained by applying the Natural Bond Orbital analysis (NBO) along with a topological perspective via the use of the Quantum Theory of Atoms in Molecules (QTAIM).
Display omitted
•Vanadium pyridone complex isomers with N- and O-coordinating modes.•Insights in to the intramolecular and intermolecular interactions.•The vanadium complexes were characterized by X-ray diffraction, FT-IR and EPR.•Natural Bond Orbital (NBO) and Quantum Theory of Atoms in Molecules (QTAIM).
Time series (1825–1973) of the Atlantic bluefin tuna,
Thunnus thynnus, landings from the trap fishery of Sardinia (W. Mediterranean) were analyzed to identify (i) patterns of catch variability in the ...historical traps of Isola Piana, Portoscuso and Porto Paglia, and (ii) effects of three local environmental variables: Mining, Run-off and Sea Surface Temperature.
We applied different time series analysis techniques: auto-correlation functions, spectral analysis and Dynamic Factor Analysis (DFA). Moreover, an asymmetrical design using a Before/After and Control/Impact location approach was used to test the perturbations due to mining processes that have characterized the fishery area.
A sharp decreasing trend of Porto Paglia trap landings beginning in 1880, coincided with mechanized mining. This result was confirmed by the ANOVAs contrasting Before vs. After (
P
<
0.01) and Controls vs. Impact location (
P
<
0.01).
We found a slight cyclical behaviour in the same time series. Spectral analysis highlighted that pattern synchronized with the Run-off cycles with periods corresponding to 7 years. We hypothesized that the effect of Run-off from watershed mine tailing dams creates a pulsing boundary ‘reflective’ effect for tuna migration schools on the in-shore trap of Porto Paglia, resulting in a periodic oscillation of captures.
We have identified (i) a reversal of trends in captures between Portoscuso and Isola Piana traps and (ii) significant differences of the monthly distribution of capture events and timing of landings (
P
<
0.01) with a higher proportion now in May, rather than in June as in the past. We assume there is a relationship with climatic changes because warmer waters can induce precocity in gonad maturation. DFA did not show any significant differences among environmental factors and landings probably because the cyclical component in Run-off is masked. We emphasize the importance of Mediterranean traditional traps as ‘sentinels’ of the homing reproductive behaviour of bluefin tuna and we argue the case for a plan to link the remaining traps in a common monitoring network.
Addition of 100 millimolar KCl, NaCl, or Na2SO4 strongly promoted acidification of the medium by cells of Nicotiana tabacum/gossii in suspension culture. Acidification was greater in the case of ...NaCl-adapted than in that of wild type cells, and strikingly so in KCl medium when fusicoccin (FC) was present. Back-titration indicated that net proton secretion in KCl medium was increased 4-fold by FC treatment in the case of adapted cells; but was not even doubled in wild type cells. Membrane potential was higher in NaCl-adapted cells. FC treatment hyperpolarized wild, but not NaCl-adapted cells, suggesting a higher degree of coupling between H+ efflux and K+ influx in adapted cells; FC enhanced net K+ uptake in adapted but not in wild cells. Acidification by cells suspended in 10 millimolar KCl was highly sensitive to vanadate, but that after addition of 100 millimolar KCl or NaCl was much less sensitive. Addition of 100 millimolar NaCl to wild type cells already provided with 10 millimolar KCl briefly accelerated, then slowed down the rate of acidification. If the addition was made after acidification had already ceased, alkalization was observed, particularly in the presence of FC. The results are consistent with the operation of a $\text{Na}^{+}-\text{H}^{+}$ antiporter.
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