Spatial and temporal variability of mobile macro-invertebrate assemblages associated to coralligenous habitat

The study aimed to investigate patterns of spatial and temporal variability of mobile macroinvertebrate assemblages associated to coralligenous habitat. A multi-factorial sampling design was used to test the hypotheses that the structure of assemblages and their spatial and temporal variability changed in relation to substrate inclination. Moreover, macroalgae and sessile macro-invertebrates were also investigated in order to detect eventual relationship between sessile and mobile assemblages. A total of 236 mobile macro-invertebrate taxa were identified, among them 2 Platyhelminthes, 4 Sipuncula, 6 Nemertea, 27 Mollusca, 86 Annelida, 103 Arthropoda, 8 Echinodermata. Results of the study showed that mobile macro-invertebrate assemblages of coralligenous habitat were little influenced by the inclination of substrate and by the morphology of sessile organisms, as patterns of variation were different between the two assemblages. Mobile macro-invertebrate assemblages changed among sampling dates within one year period and they showed high variability at the spatial scale examined

Epiphytic Communities On Posidonia Oceanica (L.) Delile Leaves Along The North Tyrrhenian Coasts (N.W. Mediterranean Sea, Italy)

The structure of epiphytic communities was studied from February to November 2000 at three different levels (upper limit, lower limit, central zone) in depth (- 5 to – 26 m) in five Posidonia oceanica(L.) Delile 1813 Tuscany coast meadows: Rosignano, San Vincenzo, Piombino, Punta Ala, Portoferraio (Isle of Elba). The study was focused on leaf epiphytes and epifauna. Three shoots in three plots were collected randomly in each area (nine shoots per area) in each site of each meadow. A quantitative description of the epiphytes and epifauna was carried out, regarding the three groups: Algae, Hydroids and Bryozoans, both on the outer and the inner surfaces of the leaf blade. The dynamics of communities of the leaf-stratum along a bathymetric gradient showed a seasonal variation characterized by the highest richness of epiphytes mainly in the upper limit, especially in early spring. Significant differences were demonstrated for the epiphytic communities of the external leaf-stratum both on the upper and the central limit of the studied meadows

Responses from olfactory sensilla of Sitophilus zeamais to Andean essential oils.

Lamiaceae species are well-known in traditional medicine. In the last years, Essential Oils (EOs) of many Lamiaceae have showed to be excellent repellents and/or insecticides. Tropical Andes are extremely rich in endemic flora, possible source of new bioactive substances. Here, we verified the insect repellent activity of the EOs extracted from Clinopodium tomentosum and C. nubigenum, two Lamiaceae typical of the Ecuadorian Andes. The two EOs were tested against the maize weevil Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae), one of the most destructive pests of stored and processed cereals. To characterize the olfactory sensilla of S. zeamais, its antennal structure was investigated by scanning and transmission electron microscopy. The electrophysiological and behavioural responses of the insect to the EOs were then investigated by electroantennography and olfactometer trials. The morphological study revealed the presence of three types of sensilla (Basiconic Sensillum 1, 2, and Grooved Peg Sensillum), that could be involved in the perception of the EOs volatile compounds. Accordingly, the electroantennography showed a positive dose-dependent response of the insect antennae to both the EOs. The behavioural tests displayed a significative repellence of the EOs, starting from 8.4 μL L-1 air, and that the efficacy and readiness of the response to the stimulus was higher for C. tomentosum. In conclusion, both the EOs are detected by the insect by its antennae and exert a strong repellent effect. The results confirm that Andean flora represents a valuable source of unexploited bioactive substances that can be utilized as promising tools for foodstuff pests’ control

A tree-decomposed transfer matrix for computing exact Potts model partition functions for arbitrary graphs, with applications to planar graph colourings

Combining tree decomposition and transfer matrix techniques provides a very general algorithm for computing exact partition functions of statistical models defined on arbitrary graphs. The algorithm is particularly efficient in the case of planar graphs. We illustrate it by computing the Potts model partition functions and chromatic polynomials (the number of proper vertex colourings using Q colours) for large samples of random planar graphs with up to N=100 vertices. In the latter case, our algorithm yields a sub-exponential average running time of ~ exp(1.516 sqrt(N)), a substantial improvement over the exponential running time ~ exp(0.245 N) provided by the hitherto best known algorithm. We study the statistics of chromatic roots of random planar graphs in some detail, comparing the findings with results for finite pieces of a regular lattice.Comment: 5 pages, 3 figures. Version 2 has been substantially expanded. Version 3 shows that the worst-case running time is sub-exponential in the number of vertice

Essential oils against Varroa destructor: a soft way to fight the parasitic mite of Apis mellifera

Essential oils (EOs) extracted from the aromatic plants Artemisia annua, Artemisia verlotiorum, Cinnamomum verum, and Citrus reticulata were investigated as repellents against the honey bees parasitic mite Varroa destructor. In laboratory tests, all EOs except C. reticulata exerted significant repellent activity against the mite after 24 h exposure. C. verumwas the most effective EO against V. destructor (median effective concentration EC50 =1.30 μL L−1), and the least toxic against honey bees (EC50 = 13.29 μL L−1). Because of its high selectivity ratio (A. mellifera LD50/V. destructor EC50 = 10.22), C. verum EO was then tested to control varroosis in colonies in field trials. The results of open field tests confirmed the efficacy observed in the laboratory. After one week of treatment, colonies treated with the EO showed a significant reduction of V. destructor infestation (about 65% at the dose of 25.0 μL L−1) and no negative effects on A. mellifera. Overall, our experiment indicated that C. verum EO could be used to effectively control varroosis in the hive with no side effects on the bee colonies

Differential effects on membrane permeability and viability of human keratinocyte cells undergoing very low intensity megasonic fields

Among different therapeutic applications of Ultrasound (US), transient membrane sonoporation (SP) - a temporary, non-lethal porosity, mechanically induced in cell membranes through US exposure - represents a compelling opportunity towards an efficient and safe drug delivery. Nevertheless, progresses in this field have been limited by an insufficient understanding of the potential cytotoxic effects of US related to the failure of the cellular repair and to the possible activation of inflammatory pathway. In this framework we studied the in vitro effects of very low-intensity US on a human keratinocyte cell line, which represents an ideal model system of skin protective barrier cells which are the first to be involved during medical US treatments. Bioeffects linked to US application at 1 MHz varying the exposure parameters were investigated by fluorescence microscopy and fluorescence activated cell sorting. Our results indicate that keratinocytes undergoing low US doses can uptake drug model molecules with size and efficiency which depend on exposure parameters. According to sub-cavitation SP models, we have identified the range of doses triggering transient membrane SP, actually with negligible biological damage. By increasing US doses we observed a reduced cells viability and an inflammatory gene overexpression enlightening novel healthy relevant strategies

Hyaluronan Hydrogels: Rheology and Stability in Relation to the Type/Level of Biopolymer Chemical Modification

BDDE (1,4-butanediol-diglycidylether)-crosslinked hyaluronan (HA) hydrogels are widely used for dermo-aesthetic purposes. The rheology and stability of the gels under physiological conditions greatly affect their clinical indications and outcomes. To date, no studies investigating how these features are related to the chemistry of the polymeric network have been reported. Here, four available HA-BDDE hydrogels were studied to determine how and to what extent their rheology and stability with respect to enzymatic hydrolysis relate to the type and degree of HA structural modification.1 H-/13 C-NMR analyses were associated for the quantification of the “true” HA chemical derivatization level, discriminating between HA that was effectively crosslinked by BDDE, and branched HA with BDDE that was anchored on one side. The rheology was measured conventionally and during hydration in a physiological medium. Sensitivity to bovine testicular hyaluronidase was quantified. The correlation between NMR data and gel rheology/stability was evaluated. The study indicated that (1) the gels greatly differed in the amounts of branched, crosslinked, and overall modified HA, with most of the HA being branched; (2) unexpectedly, the conventionally measured rheological properties did not correlate with the chemical data; (3) the gels’ ranking in terms of rheology was greatly affected by hydration; (4) the rheology of the hydrated gels was quantitatively correlated with the amount of crosslinked HA, whereas the correlations with the total HA modification level and with the degree of branched HA were less significant; (5) increasing HA derivatization/crosslinking over 9/3 mol% did not enhance the stability with respect to hyaluronidases. These results broaden our knowledge of these gels and provide valuable information for improving their design and characterization

Fixture-abutment connection surface and micro-gap measurements by 3D micro-tomographic technique analysis

X-ray micro-tomography (micro-CT) is a miniaturized form of conventional computed axial tomography (CAT) able to investigate small radio-opaque objects at a-few-microns high resolution, in a non-destructive, non-invasive, and tri-dimensional way. Compared to traditional optical and electron microscopy techniques, which provide two-dimensional images, this innovative investigation technology enables a sample tri-dimensional analysis without cutting, coating or exposing the object to any particular chemical treatment. X-ray micro-tomography matches ideal 3D microscopy features: the possibility of investigating an object in natural conditions and without any preparation or alteration; non-invasive, non-destructive, and sufficiently magnified 3D reconstruction; reliable measurement of numeric data of the internal structure (morphology, structure and ultra-structure). Hence, this technique has multi-fold applications in a wide range of fields, not only in medical and odontostomatologic areas, but also in biomedical engineering, materials science, biology, electronics, geology, archaeology, oil industry, and semi-conductors industry. This study shows possible applications of micro-CT in dental implantology to analyze 3D micro-features of dental implant to abutment interface. Indeed, implant-abutment misfit is known to increase mechanical stress on connection structures and surrounding bone tissue. This condition may cause not only screw preload loss or screw fracture, but also biological issues in peri-implant tissues

Opioid activity profiles of oversimplified peptides lacking in the protonable N-terminus

Recently, we described cyclopeptide opioid agonists containing the D-Trp-Phe sequence. To expand the scope of this atypical pharmacophore, we tested the activity profiles of the linear peptides Ac-Xaa-Phe-Yaa (Xaa = L/D-Trp, D-His/Lys/Arg; Yaa = H, GlyNH2). Ac-D-Trp-PheNH2 appeared to be the minimal binding sequence, while Ac-D-Trp-Phe-GlyNH 2 emerged as the first noncationizable short peptide (partial) agonist with high \u3bc-opioid receptor affinity and selectivity. Conformational analysis suggested that 5 adopts in solution a \u3b2-turn conformation. \ua9 2012 American Chemical Society

Ultrasound delivery of Surface Enhanced InfraRed Absorption active gold-nanoprobes into fibroblast cells: a biological study via Synchrotron-based InfraRed microanalysis at single cell level

Ultrasound (US) induced transient membrane permeabilisation has emerged as a hugely promising tool for the delivery of exogenous vectors through the cytoplasmic membrane, paving the way to the design of novel anticancer strategies by targeting functional nanomaterials to specific biological sites. An essential step towards this end is the detailed recognition of suitably marked nanoparticles in sonoporated cells and the investigation of the potential related biological effects. By taking advantage of Synchrotron Radiation fourier transform infrared micro-spectroscopy (SR-microftiR) in providing highly sensitive analysis at the single cell level, we studied the internalisation of a nanoprobe within fibroblasts (NIH-3T3) promoted by low-intensity US. To this aim we employed 20 nm gold nanoparticles conjugated with the IR marker 4-aminothiophenol. The significant Surface Enhanced Infrared Absorption provided by the nanoprobes, with an absorbance increase up to two orders of magnitude, allowed us to efficiently recognise their inclusion within cells. Notably, the selective and stable SR- microftiR detection from single cells that have internalised the nanoprobe exhibited clear changes in both shape and intensity of the spectral profile, highlighting the occurrence of biological effects. Flow cytometry, immunofluorescence and murine cytokinesis-block micronucleus assays confirmed the presence of slight but significant cytotoxic and genotoxic events associated with the US-nanoprobe combined treatments. our results can provide novel hints towards US and nanomedicine combined strategies for cell spectral imaging as well as drug delivery-based therapies