4,748 research outputs found
Molecular detection of parasites (Trematoda, Digenea: Bucephalidae and Monorchiidae) in the European flat oyster Ostrea edulis (Mollusca: Bivalvia)
Members of the globally distributed bivalve family Ostreidae (oysters) have a significant role in marine ecosystems and include species of high economic importance. In this work, we report the occurrence of digenean parasites of the families Bucephalidae (Prosorhynchoides sp.) and Monorchiidae (Postmonorchis sp.) in Mediterranean native populations of Ostrea edulis (but not in the introduced Magallana gigas). Molecular detection was based on DNA sequencing of the ribosomal intergenic spacer 2 (ITS2) marker. The importance of detecting the presence of overlooked digenean parasites in Mediterranean oysters is discussed. © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Development and reproduction of Cataclysta lemnata, a potential natural enemy of the invasive alien duckweed Lemna minuta in Italy
Life cycle of the aquatic moth Cataclysta lemnata (Lepidoptera: Crambidae) was studied in laboratory conditions to obtain a basic biological knowledge useful for predicting the possible success of the herbivorous larvae of this insect as potential control agents in limiting the spread of the invasive American duckweed Lemna minuta (Alismatales: Araceae) in Italy. The multivoltinism of C. lemnata, as well as the high overall emergence from the pupal stage (85%), the high success in mating among the formed couples (>90%), and the high number of larvae born from each egg laying (on average 310 individuals), suggest that the insect can be successfully bred in the laboratory for the purposes of an augmentative biological control. Under experimental conditions, larvae developed in 23 days (through six larval instars, distinguishable by cephalic capsule dimensions) and pupae in 10, with no difference in duration between females and males. The larval phase resulted longer than the adult one (23 vs 10 days), therefore it can be considered the most suitable stage for releasing the insect in field for biocontrol purposes. Indeed, the larvae having a herbivorous diet might consume large amount of the invasive plant, contrarily to the adult phase which is focused exclusively on reproduction. The results emerged not only allow to contribute to the knowledge on aquatic lepidoptera that are scarcely known, but also support the effectiveness of a possible protocol for an augmentative biological control of the invasive alien duckweed L. minuta
Morphology of a new blister beetle (Coleoptera, Meloidae) larval type challenges the evolutionary trends of phoresy-related characters in the genus Meloe
The discovery of some specimens of a new first instar larval type in blister beetles, collected in Iran on Anthophora bees, confirms the existence of repetitive and parallel trends in morphological specialization to phoresy in distinct lineages of Meloidae and in particular in the subfamily Meloinae. The new Iranian larva, herein described and illustrated, shows several characters and a peculiar phoretic strategy that closely parallel that of the Meloe subgenus Lampromeloe, with similar modifications of the fronto-clypeal setae into strong lanceolate spines used to pierce the intersegmental membranes of the bees. Both parallel and shared derived evolution of these characters seem possible. The coexistence in this larva of characters in both primitive and derived state is of particular interest in order to analyse the different rates and trends of evolution of phoretic adaptations. A morphological comparison (SEM) of this new meloine larva (incertae sedis), tentatively assignable to Meloe, with the M. (Lampromeloe) larvae is carried out in order to discuss the evolutionary implications of its placement in Lampromeloe, and the relative characters that would support it, vs other possible alternative scenarios
Effects of natural compounds on microbial safety and sensory quality of Fior di Latte cheese, a typical Italian cheese.
This work presents a preliminary study to assess the efficiency of plant essential oils as natural food preservatives in Fior di Latte cheese. Selected compounds were directly dissolved into Fior di Latte brine. Packaged Fior di Latte samples were stored at 10 degrees C for about 6 d. The cell loads of spoilage and useful microorganisms were monitored to calculate the microbial acceptability limit. Results show that some tested compounds were not acceptable by the panel from a sensorial point of view. Most compounds did not affect the microbial acceptability limit value to a great extent, and only a few such as lemon, sage, and thyme markedly prolonged the microbial acceptability limit of the investigated fresh cheese. Moreover, the above active agents exerted an inhibitory effect on the microorganisms responsible for spoilage without affecting the dairy microflora
Definition and description of larval types of Cyaneolytta (Coleoptera Meloidae) and new records of their phoretic association with Carabidae (Coleoptera)
The hypothesis of a general phoretic association of Cyaneolytta Péringuey 1909 triungulins (Meloidae) with Anthiini (Carabidae) is supported by many new records from several regions of Africa and India. Four morphological larval types of Cyaneolytta are described and some morpho-species belonging to different morphotypes are identified and illustrated
Evidences for strong directional resonances in intensely deformed zones of the Pernicana fault, Mount Etna, Italy
In this paper we investigate ground motion properties in the western part of the Pernicana fault. This is the major fault of Mount Etna and drives the dynamic evolution of the area. In a previous work, Rigano et al. (2008) showed that a significant horizontal polarization characterizes ground motion in fault zones of Mount Etna, both during earthquakes and ambient vibrations. We have performed denser microtremor measurements in the NE rift segment and in intensely deformed zones of the Pernicana fault at Piano Pernicana. This study includes mapping of azimuth-dependent horizontal-to-vertical spectral ratios along and across the fault, frequency–wave number techniques applied to array data to investigate the nature of ambient vibrations, and polarization analysis through the conventional covariance matrix method. Our results indicate that microtremors are likely composed of volcanic tremor. Spectral ratios show strong directional resonances of horizontal components around 1 Hz when measurements enter the most damaged part of the fault zone. Their polarization directions show an abrupt change, by 20° to 40°, at close measurements between the northern and southern part of the fault zone. Recordings of local earthquakes at one site in the fault zone confirm the occurrence of polarization with the same angle found using volcanic tremor. We have also found that the directional effect is not time-dependent, at least at a seasonal scale. This observation and the similar behavior of volcanic tremors and earthquake-induced ground motions suggest that horizontal polarization is the effect of local fault properties. However, the 1-Hz resonant frequency cannot be reproduced using the 1-D vertically varying model inferred from the array data analysis, suggesting a role of lateral variations of the fault zone. Although the actual cause of polarization is unknown, a role of stress-induced anisotropy and microfracture orientation in the near-surface lavas of the Pernicana fault can be hypothesized consistently with the sharp rotation of the polarization angle within the damaged fault zone
Issues in Choosing the References to Use for Spectral Ratios from Observations and Modeling at Cavola Landslide in Northern Italy
A reference site has to be free of amplification or de-amplification effects, namely with no troughs and peaks in its Fourier amplitude spectrum. At the Cavola landslide we show that this spectrum is dependent on the direction of propagation of wave fronts for incidence angles in the range 30° to 90°. Our study is based on comparison of spectral ratios from observations and 2D numerical simulations. We have modeled propagation in a 2D profile for SH and SV waves with several incidence angles in the 0° ±90° range, where 0° and 90° are respectively vertical and horizontal incidence, except that ±90° denotes Rayleigh waves in the P-SV. We discuss in detail the result for angles of incidence of 0, ±20°, ±60°, ±90°. We have obtained observed horizontal-to-horizontal earthquakes spectral ratios using three reference sites. Two of these have matching receivers in the model, located at the opposite ends of the 2D profile. Overall observations are matched best when the reference site is located on the same side of the landslide as the incoming wave front. We also find general agreement of the observed H/H spectral ratios from earthquakes with H/V and H/H spectral ratios from noise, and the match between H/V values from noise and synthetic spectral ratios using an absolute, flat half-space reference is very good. On the other hand, 1D modeling performs poorly in comparison with 2D modeling in our case, for which the shape ratio h/D = 0.2 is intermediate between primarily-1D and strongly-2D wave propagation according to the classification of Bard and Bouchon (1985)
Shelf life of Stracciatella cheese under modified-atmosphere packaging
The aim of this work is to evaluate the shelf life of Stracciatella cheese packaged in a protective atmosphere, using 4 different CO(2):N(2):O(2) gas mixtures [50:50:0 (M1), 95:5:0 (M2), 75:25:0 (M3), and 30:65:5 (M4) vol/vol] and stored at 8 degrees C. Cheese in traditional tubs and under vacuum were used as the controls. Results showed that the modified-atmosphere packaging, in particular M1 and M2, delayed microbial growth of spoilage bacteria, without affecting the dairy microflora, and prolonged the sensorial acceptability limit
Olfactory Marker Protein in the Human Carotid Body
Background: Transduction mechanisms of the hypoxic chemoreflex elicited by carotid body (CB) chemoreceptor cells remain unclear. Recent studies direct attention to the plausible link between CB and olfactory chemoreceptor functions.Methods: Here we used immunohistochemistry to investigate the distribution and localization of olfactory marker protein (OMP) in human CB. Carotid bodies were collected post-mortem from hospital patients aged 27-76 years who died from reasons unre-lated to chronic pulmonary or cardiovascular disorders. We used specific antibodies to selectively identify CB cells and OMP in tissue sections. The binding of antibodies to target antigens was visualized with the Ultra Vision detection system.Results: We show that OMP is abundantly present in the cytoplasm of CB chemoreceptor cells. The presence of OMP in these cells indicates that the olfactory system may participate in shaping the chemosensory CB function.Conclusions: The findings support the notion that the transduction mechanisms of chemoreceptive systems contain a degree of homology, irrespective of the anatomical localization and the functional role these systems fulfill. The ectopic presence of OMP in CB broadens the current understanding of the mechanisms underlying chemosensory responses
Region-specific effects on brain metabolites of hypoxia and hyperoxia overlaid on cerebral ischemia in young and old rats: a quantitative proton magnetic resonance spectroscopy study
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