Search results for "Mphi"

Supramolecular Aggregates in Vacuum: Positively Mono-Charged Sodium Alkanesulfonate Clusters

2010

The formation and structural features of positively mono-charged aggregates of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and sodium methane—(MetS), butane—(ButS) and octane—(OctS) sulfonate molecules in the gas phase have been investigated by electrospray ionization mass spectrometry, energy-resolved mass spectrometry and density functional theory (DFT) calculations. The experimental results show that the center-of-mass collision energy required to dissociate 50% of these mono-charged aggregates scantly depends on the length of the alkyl chain as well as on the aggregation number. This, together with the large predominance of mono-charged species in the mass spectra, was rationalized i…

Organized assemblies of magnetic clusters

2003

Abstract In this work we have explored the possibilities to create layered organizations of the Mn 12 single-molecule magnets using the Langmuir–Blodgett technique or attaching these clusters onto a metal surface by preparing self-assembled monolayers (SAMs). In the first part we discuss the use of the Langmuir–Blodgett (LB) technique in order to obtain organized magnetic films formed by monolayers of these clusters. Two strategies have been used with this aim. The first one consists of mixing Mn 12 acetate or benzoate derivatives with an amphiphile, while the second procedure is based on the use of Mn 12 derivatives specifically designed to form LB films. An alternative method is that of p…

Techniques de construction traditionnelles et techniques romaines dans le théâtre d’Althiburos et les monuments de spectacle de l’Afrique Proconsulai…

2023

The contribution aims to study the relationship between the traditional construction techniques of the territories of Proconsular Africa and those imported by the Romans and used in the construction of entertainment buildings, in particular theaters and amphitheatres, also taking into account the importation of typological models, starting from the “case study” of the theater of Althiburos. During the 1st and 2nd centuries AD there is a gradual introduction of Roman construction techniques, such as the opus caemaenticium, especially in the construction of substructures and vaults, sometimes with the importation of urban models, of techniques but also of Italic workers (just think of the opu…

Palaeohistology helps reveal taxonomic variability in exceptionally large temnospondyl humeri from the Upper Triassic of Krasiejów, SW Poland

2023

For more than twenty years, palaeontological excavations have been carried out at the Upper Triassic site of Krasiejów (south-west Poland), providing thousands of skeletal elements belonging to various tetrapod groups. However, almost all bones are preserved in a disarticulated state. This generates problems in taxonomic assignment among closely related groups, e.g., stereospondyl amphibians. As far as cranial elements, the pectoral girdle bones and the intercentra are very diagnostic, while all other remaining skeletal elements are difficult to unambiguously assign between either the capitosaurid Cyclotosaurus intermedius or the trematosaurid Metoposaurus krasiejowensis, both originating f…

Much more than a clasp : evolutionary patterns of amplexus diversity in anurans

2020

The evolution and diversification of animal reproductive modes have been pivotal questions in behavioural ecology. Amphibians present the highest diversity of reproductive modes among vertebrates, involving various behavioural, physiological and morphological traits. One such feature is the amplexus, which is the clasp or embrace of males on females during reproduction and is found almost universally in anurans. Hypotheses about the origin of amplexus are limited and have not been tested thoroughly, nor have they taken into account evolutionary relationships in most comparative studies. However, these considerations are crucial to an understanding of the evolution of reproductive modes. Her…

Breeding phenology of Bufo viridis Laurenti, 1768 in Sicily (S Italy)

2006

Inhibition of amphibian egg development by histones

1966

Uova di Anuri (Discoglossus pictus) sono state trattate con istoni. II trattamento con la frazione ricca in lisina (0,4-0,1 mg/ml) durante la segmentazione causa blocco alle prime divisioni. Con concentrazioni minori (0,05–0,025 mg/ml) lo sviluppo si arresta allo stadio di gastrula. La sensibilita al trattamento decresce notevolmente dopo la gastrulazione. La frazione ricca in arginina e risultata meno efficace.

Übertragung von Verhaltensweisen durch Transplantation von Anlagen neuroanatomischer Strukturen bei Amphibienlarven

2010

By replacing parts of the neural plate (prospective medulla oblongata) of Triturus vulgaris by neural ectoderm of Xenopus laevis larval chimaeras were obtained, which showed donorlike rhythmical movements of distinct parts of the visceral musculature according to the place of implantation. Especially the branchial region with its external gills showed rhythmical movements and is the special object of this investigation.

Amphibian Immune System

1998

The temnospondyl amphibian Cyclotosaurus from the Upper Triassic of Poland

2005

A gap in the Late Triassic fossil record of the capitosaur amphibian Cyclotosaurus is filled by new material from lacustrine deposits at Krasiejow, Poland, corresponding in age to the Lehrberg Beds (late Carnian) of Germany. The skull of the Polish cyclotosaur is intermediate in several respects between that of Cyclotosaurus robustus from the middle Carnian Schilfsandstein of Germany and the younger C. mordax from the early Norian Stubensandstein. It shows a decrease in the width of the skull and in the degree of con- cavity of the posterior margin of the skull roof. The differ- ences are significant enough to warrant erection of a novel species, the name Cyclotosaurus intermedius sp. nov. …