2,299 research outputs found
Systematics of the Mesalina guttulata species complex (Squamata: Lacertidae) from Arabia with the description of two new species
Mesalina are small diurnal lacertid lizards inhabiting arid areas from North Africa to northwestern India. Previous phylogenetic studies have shown the existence of several species complexes within the genus, some of them with high levels of
undiscovered diversity. In the present study, we carry out an integrative systematic revision of the Mesalina guttulata species complex using both molecular and morphological data from across its entire distribution range in North Africa, the
Middle East and Arabia. The results of the genetic analyses indicate that M. guttulata and M. bahaeldini are two allopatric
sister taxa separated by the Suez Canal and that the species complex includes a further three unnamed deep phylogenetic
lineages, two of them restricted to southern and southwestern Arabia and described herein as Mesalina austroarabica sp.
nov. and Mesalina arnoldi sp. nov., respectively. As a result of the lack of enough material, the third deep lineage, distributed across Kuwait, Saudi Arabia and Jordan, is provisionally left undescribed. The two newly described species are characterized by their size, scale counts and tail coloration, as well as differences at the three mitochondrial and one nuclear
gene analyzed in the present study
Sul sindacato giudiziale delle operazioni con parti correlate
Nello scritto si affronta la questione legata ai limiti del sindacato giudiziale sulle operazioni con parti correlate. In particolare, è discusso se si applichi la c.d. business judgement rule, che implica un arretramento dello scrutinio giudiziale. Dopo aver evidenziato gli equivoci in cui sovente si incorre nell’impostazione del problema, viene esaminato il rapporto fra qualità delle procedure in tema di operazioni con parti correlate e intensità del controllo dei giudici e si evidenzia il costo, in termini di indeterminatezza, della tesi che pone in rapporto di proporzionalità inversa qualità del processo e intensità del vaglio giudiziale. In alternativa si propone di subordinare l’applicazione della business judgement rule alla circostanza che le operazioni di maggiore rilevanza con soci correlati siano sottoposte all’assemblea con applicazione del meccanismo del c.d. whitewash, anche in presenza di parere favorevole degli amministratori indipendenti
Morphometric comparisons between extant and extinct Italian populations of the adder, Vipera berus (Linnaeus, 1758)
Development of a petroleum knowledge tutorial system for university and corporate training
The increasingly rapid development of the disciplines of petroleum engineering and petroleum geology has led to new methodologies and interpretation techniques forming new knowledge that should be offered quickly and efficiently to modern engineers and geologists. This need is equally important for students as well as for young professionals. Access and training to all scientific information is necessary to ensure success in their future careers. Today, e-learning has become a common medium for the management and distribution of on-line educational content. Learning Management Systems (LMSs) were not only developed to handle a large variety of multimedia content that provides an organized knowledge repository used to accelerate access to information and skill acquisition; but, LMSs can also keep detailed statistics on the use of the available material offering a powerful training and educational tool. In this document, the Petroleum Knowledge Tutorial System, an LMS platform offering a variety of online educational and training options to petroleum engineers and geologists, is presented. It was created using Moodle, open-source software that can be used to create on-line courses. The platform covers fundamental educational concepts in a structured way. It follows an optimized "workflow" that can be applied not only to solve a specific exercise but also any similar problem encountered over the course of one's career. The platform was designed to offer a repository of learning material in various forms and to favor user-platform interactions. It can be used for training and evaluation purposes through exercises and problem solving that the user can perform online by using browsing software along with internet access. Special tools were created and implemented on the platform to assist the user in completing a variety of tasks including performing exercises involving calculations with given data and plots of points or lines on graphs without leaving the learning environment. Furthermore, videos with detailed explanations follow each learning module and provide the full solution to every exercise. The LMS automatically keeps a large statistical database including the users' access to activities on the platform that can be exported and further processed to improve the platform functionality and evaluate the users' performance
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