Search results for "Horns"
showing 10 items of 14 documents
Sedimentary environment, lithostratigraphy and dating of sediment sequences from Arctic lakes Revvatnet and Svartvatnet in Hornsund, Svalbard
2016
Abstract The sedimentary environment, sediment characteristics and age-depth models of sediment sequences from Arctic lakes Revvatnet and Svartvatnet, located near the Polish Polar Station in Hornsund, southern Svalbard (77°N), were studied with a view to establishing a basis for paleolimnological climate and environmental reconstructions. The results indicate that catchment-to-lake hydroclimatic processes probably affect the transportation, distribution and accumulation of sediments in different parts of lakes Revvatnet and Svartvatnet. Locations with continuous and essentially stable sedimentary environments were found in both lakes between water depths of 9 and 26 m. We used several diff…
MERCES… SENTICOSA. Immaginari stoici nei Floridia di Apuleio
2020
Merces… senticosa. Stoic images in the Florida of Apuleius · In the Florida Apuleius makes use of images related to the rhetorical-philosophical stoic tradition. In particular, in Fl. 18 Apuleius describes the famous sophism of Protagoras, by using, trought an intellectual virtuosity, the metaphor of thorns, a stylistic device linked with the characterization of the Stoicism.
Sensor Properties of Pristine and Functionalized Carbon Nanohorns
2016
Nanodispersions of pristine single-wall carbon nanohorns (i.e., p-SWCNHs) and oxidized-SWCNHs (i.e.; o-SWCNHs) were used to modify screen printed electrode (SPE). p-SWCNHs and o-SWCNHs were fully characterized by using several analytical techniques, as: HR-TEM (High Resolution-Transmission Electron Microscopy), FE-SEM/EDX (Field Emission-Scanning Electron Microscopy/Energy Dispersive X-ray Analysis), Raman spectroscopy, thermogravimetric analysis, differential thermal analysis (DTA), and the Brunauer-Emmett-Teller (BET) method. The chemically modified SPEs were also characterized with Cyclic Voltammetry (CV), using several different electro-active targets. In all cases, p-SWCNHs showed bett…
Imidazolium-Functionalized Carbon Nanohorns for the Conversion of Carbon Dioxide
2016
Six new hybrid materials composed of carbon nanohorns (CNHs) and highly cross-linked imidazolium salts were easily synthesized using a one-step procedure based on the radical oligomerization of bis-vinylimidazolium salts (bVImiX) in the presence of pristine CNHs. The hybrid materials were characterized and employed as the sole catalysts for the conversion of carbon dioxide into cyclic carbonate by reaction with epoxides. The solids displayed excellent turnover number and productivity. Moreover, four catalysts were investigated in recycling experiments. Two catalysts containing an octyl linker between the imidazolium units and a bromide or an iodide anion showed no loss in activity after thr…
Non-conventional methods and media for the activation and manipulation of carbon nanoforms
2013
Very often, chemical transformations require tedious and long procedures, which, sometimes, can be avoided using alternative methods and media. New protocols, enabling us to save time and solvents, allow us also to explore new reaction profiles. This Tutorial Review focuses on the physical and chemical behavior of carbon nanoforms, CNFs (fullerenes, nanotubes, nanohorns, graphene, etc.) when non-conventional methods and techniques, such as microwave irradiation, mechano-chemistry or highly ionizing radiations are employed. In addition, the reactivity of CNFs in non-conventional media such as water, fluorinated solvents, supercritical fluids, or ionic liquids is also discussed.
THE INTENSITY OF SEXUAL SELECTION PREDICTS WEAPON SIZE IN MALE BOVIDS
2007
As a classical example of a sexually selected trait, the horns of male bovids offer a prime opportunity to identify predictors of the intensity of sexual selection. Here I use the comparative method to quantify sexual and natural selection pressures behind interspecific variation in horn length. I show that male horn length depends on factors proposed to affect the mean mate number per mating male, correlating positively with group size and negatively with male territoriality. This suggests that whereas group size increases the opportunity for sexual selection, territoriality reduces it because territorial males are unable to follow and monopolize female groups as effectively as males in no…
Intralocus tactical conflict: Genetic correlations between fighters and sneakers of the dung beetle Onthophagus taurus
2015
Males and females differ in their phenotypic optima for many traits, and as the majority of genes are expressed in both sexes, some alleles can be beneficial to one sex but harmful to the other (intralocus sexual conflict; ISC). ISC theory has recently been extended to intrasexual dimorphisms, where certain alleles may have opposite effects on the fitness of males of different morphs that employ alternative reproductive tactics (intralocus tactical conflict; ITC). Here, we use a half-sib breeding design to investigate the genetic basis for ISC and ITC in the dung beetle Onthophagus taurus. We found positive heritabilities and intersexual genetic correlations for almost all traits investigat…
Pregnancy after syngeneic uterus transplantation and spontaneous mating in the rat.
2010
BACKGROUND: Uterus transplantation (UTx) research aims towards the introduction of UTx as a treatment for uterine factor infertility. The rat model is the principal rodent model used and this study aims to assess the potential for pregnancy and to assess effects on pregnancy outcome. METHODS: Female Lewis rats underwent hysterectomy and received syngeneic uterine transplants (with one horn removed) by end-to-side anastomosis between the common iliac vessels of the recipient and the graft. The graft was placed in an orthotopic position with anastomosis to the upper part of the native uterine horn and vagina to allow for pregnancy by mating. Controls had only one uterine horn removed. Mating …
Adaptation of the tropical hybrid Euphorbia×lomi Rauh to the exposure to the Mediterranean temperature extremes
2014
Abstract Poysean ( Euphorbia × lomi Rauh) has been introduced in the Mediterranean countries as an ornamental plant for indoor uses. When used outdoor, few information is available about its ability to withstand the Mediterranean temperature extremes. An experiment in an open stand was performed to evaluate poysean tolerance to the winter and summer temperatures of the thermo Mediterranean climate and its ornamental value for urban greening. Two genotypes of poysean (Nguen Muang, NM; and Soi Budsanin, SB) with similar bracts and flower colours were grown at either 2 or 3 plants per pot during 23 months. Number of flower racemes and leaves per plant and plant height were recorded monthly. Ov…
Horn growth rate and longevity: implications for natural and artificial selection in thinhorn sheep (Ovis dalli).
2007
We used horn measurements from natural and hunted mortalities of male thinhorn sheep Ovis dalli from Yukon Territory, Canada, to examine the relationship between rapid growth early in life and longevity. We found that rapid growth was associated with reduced longevity for sheep aged 5 years and older for both the hunted and natural mortality data sets. The negative relationship between growth rate and longevity in hunted sheep can at least partially be explained by morphologically biased hunting regulations. The same trend was evident from natural mortalities from populations that were not hunted or underwent very limited hunting, suggesting a naturally imposed mortality cost directly or in…