Graphene oxide affects in vitro fertilization outcome by interacting with sperm membrane in an animal model

We realized the exposure of boar spermatozoa to graphene oxide (GO) at concentration of 0.5, 1, 5, 10 and 50 μg/mL in an in vitro system able to promote the capacitation, i.e. the process that allows sperm cells to became fertile. Interestingly, we found that the highest GO concentration (5, 10 and 50 μg/mL) are toxic for spermatozoa, while the lowest ones (0.5 and 1 μg/mL) seem to significantly increase the sperm cells fertilizing ability (p >.05) in an in vitro fertilization experiment. To explain this finding, we investigated the effect of GO on sperm membrane structure (atomic force microscopy) and function (confocal microscopy and flow cytometry, substrate adhesion). As a result, we found that GO is able to interact with spermatozoa membranes and, in particular, it seems to be able to extract the cholesterol, which is a key player in spermatozoa physiology, from plasma membrane of boar spermatozoa incubated under capacitation conditions. In our opinion, these results are very important because they allow identifying either a plausible mechanism of GO toxicity on spermatozoa and new strategies to manage sperm capacitation

Type-1 Cannabinoid Receptors Reduce Membrane Fluidity of Capacitated Boar Sperm by Impairing Their Activation by Bicarbonate

Background Mammalian spermatozoa acquire their full fertilizing ability (so called capacitation) within the female genital tract, where they are progressively exposed to inverse gradients of inhibiting and stimulating molecules. Methodology/Principal Findings In the present research, the effect on this process of anandamide, an endocannabinoid that can either activate or inhibit cannabinoid receptors depending on its concentration, and bicarbonate, an oviductal activatory molecule, was assessed, in order to study the role exerted by the type 1 cannabinoid receptor (CB1R) in the process of lipid membrane remodeling crucial to complete capacitation. To this aim, boar sperm were incubated in vitro under capacitating conditions (stimulated by bicarbonate) in the presence or in the absence of methanandamide (Met-AEA), a non-hydrolysable analogue of anandamide. The CB1R involvement was studied by using the specific inhibitor (SR141716) or mimicking its activation by adding a permeable cAMP analogue (8Br-cAMP). By an immunocytochemistry approach it was shown that the Met-AEA inhibits the bicarbonate-dependent translocation of CB1R from the post-equatorial to equatorial region of sperm head. In addition it was found that Met-AEA is able to prevent the bicarbonate-induced increase in membrane disorder and the cholesterol extraction, both preliminary to capacitation, acting through a CB1R-cAMP mediated pathway, as indicated by MC540 and filipin staining, EPR spectroscopy and biochemical analysis on whole membranes (CB1R activity) and on membrane enriched fraction (C/P content and anisotropy). Conclusions/Significance Altogether, these data demonstrate that the endocannabinoid system strongly inhibits the process of sperm capacitation, acting as membrane stabilizing agent, thus increasing the basic knowledge on capacitation-related signaling and potentially opening new perspectives in diagnostics and therapeutics of male infertility

From influence to impact: the multifunctional land-use in Mediterranean prehistory emerging from palynology of archaeological sites (8.0-2.8 ka BP)

Archaeobotany is used to discover details on local land uses in prehistoric settlements developed during the middle and beginning of late Holocene. Six archaeological sites from four countries (Spain, Italy, Greece, and Turkey) have pollen and charcoal records showing clear signs of the agrarian systems that had developed in the Mediterranean basin during different cultural phases, from pre-Neolithic to Recent Bronze Age. A selected list of pollen taxa and sums, including cultivated trees, other woody species, crops and annual or perennial synanthropic plants are analysed for land use reconstructions. In general, cultivation has a lower image in palynology than forestry, and past land uses became visible when oakwoods were affected by human activities. On-site palynology allows us to recognise the first influence of humans even before it can be recognised in off-site sequences, and off-site sequences can allow us to determine the area of influence of a site. Neolithic and Bronze Age archaeological sites show similar land use dynamics implying oak exploitation, causing local deforestation, and cultivation of cereal fields in the area or around the site. Although a substantial difference makes the Neolithic influence quite distant from the Bronze Age impact, mixed systems of land exploitation emerged everywhere. Multiple land use activities exist (multifunctional landscapes) at the same time within the area of influence of a site. Since the Neolithic, people have adopted a diffuse pattern of land use involving a combination of diverse activities, using trees\u2013crops\u2013domesticated animals. The most recurrent combination included wood exploitation, field cultivation and animal breeding. The lesson from the past is that the multifunctional land use, combining sylvo-pastoral and crop farming mixed systems, has been widely adopted for millennia, being more sustainable than the monoculture and a promising way to develop our economy

A range profiling technique for synthetic wideband radar

A technique is proposed for reconstructing wide range profiles using stepped-frequency waveforms (SWFs). The technique is based on reconstructing range sub-profiles. With respect to previous methods, the proposed technique can be applied to any kind of SWFs. Moreover, for a given range resolution, long range profiles can be formed without increasing the number of transmitted frequencies. Theoretical results are also derived that provide a correct setting of waveform and processing parameter. Finally, as case studies, the proposed method is applied to three SFWs, namely short-pulse stepped-frequency, linear frequency modulated stepped frequency and phase-coded stepped-frequency waveforms. Simulations prove the effectiveness of the proposed range profile reconstruction

Polymer Nanocomposites Containing Anisotropic Metal Nanostructures as Internal Strain Indicators

Polymer/metal nanocomposite containing intrinsically anisotropic metal nanostructures such as metal nanorods and nanowires appeared extremely more sensitive and responsive to mechanical stimuli than nanocomposites containing spherical nanoparticles. After uniaxial stretching of the supporting polymer matrix (poly(vinyl alcohol)), the elongated silver nanostructures embedded at low concentration into the polymer matrix (<1 wt % of Ag) assume the direction of the drawing, yielding materials with a strong dichroic response of the absorption behavior. Accordingly, the film changed its color when observed under linearly polarized light already at moderate drawings. The results obtained suggest that nanocomposite films have potential in applications such as color polarizing filters, radiation responsive polymeric objects and smart flexible films in packaging applications

Provenienza ed uso degli oggetti in pietra.

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Faunal exploitation in an Early Neolithic site: the assemblage from Casa Gazza (Travo, Piacenza, Northern Italy)

The faunal assemblage of Casa Gazza, providing new data to lighten the economic model of the Early Neolithic communities in northern Italy, represents a significative evidence in the Po Plain. The settlement, a half-buried pit, is located on a large terrace on the left bank of the Trebbia River (150 m a.s.l.), in the area of Travo (Piacenza, northern Italy). The results of zooarchaeological, taphonomic and paleoecological analyses are here discussed. The faunal assemblage consists of 7,354 remains of which 1,417 were identified (NISp). Faunal composition shows a prevalence of domestic animals on the wild ones. Butchery marks are well documented and several modifications are related to hard animal material manufacturing. Comparisons with Neolithic sites of the Po Plain, show that the economy at Casa Gazza was characterized by a fully-developed sedentary breeding.La contribution fournie par Casa Gazza à la connaissance et à la reconstruction du modèle économique des premières communautés du Néolithique du nord de l’Italie représente un important témoignage dans la plaine du Pô. Le site, qui se caractérise par une fosse à demi enterrée, est situé sur une grande terrasse sur la rive gauche de la rivière Trebbia (150 m a.s.l.), dans la région de Travo (Piacenza, Italie du Nord). Les résultats des analyses archéozoologiques, taphonomiques et paléoécologiques sont présentés ici. L’assemblage faunique est composé de 7.354 restes, dont 1.417 ont été identifiés au niveau spécifique. La composition de la faune montre une prévalence d’animaux domestiques par rapport aux animaux sauvages. Les stries de découpe de boucherie sont bien documentées et plusieurs modifications sont liées à la fabrication d’artefacts en matière dure animale. Les comparaisons avec les sites néolithiques de la plaine du Pô montrent comment l’économie de Casa Gazza était caractérisée par un élevage sédentaire pleinement développé

Endocannabinoid-binding CB1 and TRPV1 receptors as modulators of sperm capacitation

Mammalian spermatozoa reach the ability to fertilize only after they complete a complex series of physical-chemical modification, the capacitation. Recently, the endocannabinoid-binding type-1cannabinoid receptor (CB1) and transient receptor potential vanilloid 1 (TRPV1) channel have been proposed to play a key role in the control of capacitation. In particular CB1, acting via a Gi protein/cAMP/PKA pathway, maintains low cAMP levels in early stages of post ejaculatory life of male gametes. By this way it promotes the maintenance of membrane stability, thus avoiding the premature fusion of plasma membrane (PM) and outer acrosome membrane (OAM), which is mandatory for the exocytosis of acrosome content. TRPV1, on the contrary, becomes active during the latest stages of capacitation, and allows the rapid increase in intracellular calcium concentration that leads to the removal of the F-actin network interposed between PM and OAM, leading to their fusion and, ultimately, to the acrosome reaction