Mountain Pygmies of Western New Guinea: A Morphological and Molecular Approach

The presence of pygmy or pygmoid groups among New Guinea populations has been the object of scientific interest since the end of the nineteenth century. Morphological and molecular data are used here to study western New Guinea population variability, focusing in particular on two pygmoid groups living in the eastern fringe highlands of Papua: the Una and the Ketengban. Various kinds of anthropometric data are examined, as well as height, weight, and body mass index, to carry out comparisons with nearby ethnic groups living in the highland and lowland regions. The Ketengban data were also compared with other data recorded 20 years before. The results of previous research on the sequencing of the mitochondrial DNA hypervariable segment 1 region and nuclear DNA nonrecombining Y-chromosome polymorphisms are presented. Both morphological and molecular studies involve adult subjects of both genders, representative of the same ethnic groups and/ or geographic regions. The pygmoid groups turn out to be significantly different from all other study groups, due to their small size, as confirmed by analysis of variance, although significant height and weight increments are observed with respect to those previously recorded. However, putative neutral genetic variation estimated from mitochondrial DNA and Y-chromosome markers support a recent shared common history between these pygmoid populations and the other central Papua groups (except for the Dani-Lani). These findings suggest that the short-stature phenotype is an independent secondary adaptation, possibly driven by an iodine-deficient environment, which leaves the potential for further investigations

From Academia Armena Sancti Lazari to the Establishment of Armenian Studies at Ca’ Foscari

The Armenian Studies have a very long tradition in Italy. However, the establishment of the official teaching of Armenian at Ca’ Foscari is particularly significant. It is a direct continuation of many Armenian traces present in the lagoon city for centuries, such as the birth of the first Casa Armena in Europe in 1245, the prosperous diplomatic relations between the Republic of Serenissima and the Kingdom of Armenia, the printing of the first Armenian book in 1512, the arrival of Armenian merchants from Julfa, who highly contributed to the economy of Venice, and finally the institution of the Mekhitarist Congregation of the Armenian monks on the island of San Lazzaro, recognised by Napoleon as Academia Armena Sancti Lazari. After an historical excursus, the paper will go on to detail some significant periods of Armenian Studies at Ca’ Foscari

Precise g

Laser-microwave double and triple resonance experiments were performed on clouds of Ba+ ions confined in a Penning ion trap to induce and detect electronic and nuclear spin flip transitions. Collisions with buffer gas molecules in the trap was used to reduce the lifetime of a long lived metastable state of the ions, in which population trapping might occur, and to cool the ions to the ambient temperature. Loss of ions from the trap by collisions were prevented by coupling the magnetron and reduced cyclotron motions by an additional r.f. field at the sum frequency of the two motions. Electronic Zeeman transitions in 138Ba+ and 135Ba+ were observed at a full width of about 3 kHz at a transition frequency of 80 GHz. The uncertainty of the line center was $3\times 10^{-9}$. From the magnetic field calibration by the cyclotron resonance of electrons stored in the same trap the gJ-factor for both isotopes could be determined to $2 \times 10^{-8}$. From radiofrequency induced $\Delta m_I = 1$ transitions of 135Ba+ the nuclear g-factor could be determined $5\times 10^{-6}$. Both measurements improve earlier results by about one order of magnitude

Subharmonic excitation of the eigenmodes of charged particles in a Penning trap

When parametrically excited, a harmonic system reveals a nonlinear dynamical behaviour which is common to non-deterministic phenomena. The ion motion in a Penning trap — which can be regarded as a system of harmonic oscillators — offers the possibility to study anharmonic characteristics when perturbed by an external periodical driving force. In our experiment we excited an electron cloud stored in a Penning trap by applying an additional quadrupole r.f. field to the endcaps. We observed phenomena such as individual and center-of-mass oscillations of an electron cloud and fractional frequencies, so-called subharmonics, to the axial oscillation. The latter show a characteristic threshold behaviour. This phenomenon can be explained with the existence of a damping mechanism affecting the electron cloud; a minimum value of the excitation amplitude is required to overcome the damping. We could theoretically explain the observed phenomenon by numerically calculating the solutions of the damped differential Mathieu equation. This numerical analysis accounts for the fact that for a weak damping of the harmonic system we observed an even-odd-staggering of the the different orders of the subharmonics in the axial excitation spectrum