The true story of Yeti, the "abominable" heterochromatic gene of drosophila melanogaster

The Drosophila Yeti gene (CG40218) was originally identified by recessive lethal mutation and subsequently mapped to the deep pericentromeric heterochromatin of chromosome 2. Functional studies have shown that Yeti encodes a 241 amino acid protein called YETI belonging to the evolutionarily conserved family of Bucentaur (BCNT) proteins and exhibiting a widespread distribution in animals and plants. Later studies have demonstrated that YETI protein: (i) is able to bind both subunits of the microtubule-based motor kinesin-I; (ii) is required for proper chromosome organization in both mitosis and meiosis divisions; and more recently (iii) is a new subunit of dTip60 chromatin remodeling complex. To date, other functions of YETI counterparts in chicken (CENtromere Protein 29, CENP-29), mouse (Cranio Protein 27, CP27), zebrafish and human (CranioFacial Development Protein 1, CFDP1) have been reported in literature, but the fully understanding of the multifaceted molecular function of this protein family remains still unclear. In this review we comprehensively highlight recent work and provide a more extensive hypothesis suggesting a broader range of YETI protein functions in different cellular processes

Integration of HVSR measures and stratigraphic constraints for seismic microzonation studies: the case of Oliveri (ME)

Because of its high seismic hazard the urban area of Oliveri has been subject of first level seismic microzonation. The town develops on a large coastal plain made of mixed fluvial/marine sediments, overlapping a complexly deformed substrate. In order to identify points on the area probably suffering relevant site effects and define a preliminary Vs subsurface model for the first level of microzonation, we performed 23 HVSR measurements. A clustering technique of continuous signals has been used to optimize the calculation of the HVSR curves. 42 reliable peaks of the H/V spectra in the frequency range 0.6–10 Hz have been identified. A second clustering technique has been applied to the set of 42 vectors, containing Cartesian coordinates, central frequency and amplitude of each peak to identify subsets which can be attributed to continuous spatial phenomena. The algorithm has identified three main clusters that cover significant parts of the territory of Oliveri. The HVSR data inversion has been constrained by stratigraphic data of a borehole. To map the trend of the roof of the seismic bedrock, from the complete set of model parameters only the depth of the seismic interface that generates peaks fitting those belonging to two clusters characterized by lower frequency has been extracted

Developing Inorganic Approaches to Polymerization and Bioconjugation

Multi-disciplinary approaches to problem solving are needed given the increasing complexity of fundamental scientific questions. This dissertation undertakes a holistic approach to research and tackles challenges spanning the biology, chemistry, and materials interface. The central theme for most projects involves applying inorganic and main group chemistry to develop new bioconjugation strategies or polymerization methodologies to access novel materials. Chapter One describes efforts in understanding the effects of trehalose polymers towards protein stabilization. The stabilization capability of polymers made from a set of styrenyl-based trehalose monomer regioisomers were studied. Polymers of each trehalose monomer regioisomer and one polymer which contained all three isomers combined were synthesized. All polymer regioisomers stabilized insulin to a similar degree towards agitation and heat stress.Chapter Two details the initial discovery that icosahedral boron-rich cluster compounds of the type B12(OR12)—where “R” can be any alkyl or aryl group— could be utilized as strong one-electron photooxidants thereby initiating the polymerization of olefins. The perfunctionalized clusters are able to initiate polymerization of a range of styrene substrates under blue LED irradiation. Also demonstrated, is the visible light initiated, metal free cationic polymerization of isobutylene into poly(isobutylene).Chapter Three introduces a new class of carborane-based chain-transfer agents (CTA’s) to be used in reversible addition-fragmentation chain-transfer (RAFT) polymerization. The carborane-based CTA’s mediate the controlled polymerization of monomers such as styrene, N-isopropylacrylamide, and methyl acrylate to produce monodisperse carborane terminated polymers. The carborane-based scaffold, appended on the polymer chain end, serves as a general 1H NMR spectroscopic handle used to elucidate polymer molecular weight. Binding of carborane into the hydrophobic cavity of β-cyclodextrin was demonstrated by isothermal titration calorimetry thereby validating its potential use as an affinity label. The carborane RAFT agents also act as Raman active probes.Chapter Four explores the reactivity of gold(III) organometallic complexes in the context of bioconjugation chemistry. The gold(III) organometallic complexes mediated the conjugation of small molecule substrates which included heterocycles, an anti-cancer drug, biotin, and low molecular weight PEG to cysteine residues on biomolecules. The bioconjugation reactions proceeded rapidly, with high efficiency, and in a broad pH range

Mechanical design and deployment of a quasi-rhombic pyramid drag sail for safe de-orbit of a 3U CubeSat

Orbital debris is rapidly becoming a more prevalent and alarming obstacle that, without immediate intervention, will undoubtedly become disastrous for human activity in space. The University of Glasgow’s microsatellite society, GU Orbit, has taken action to equip its 3U CubeSat ASTRAEUS-01 with a drag sail de-orbit device. This payload represents a simple and low-cost solution for the mitigation of debris in Low Earth Orbit (LEO) and is expected de- orbit the CubeSat within 12 to 24 months, depending on solar activity. These aspects are deemed fundamental for the mission and align with GU Orbit’s ethics of promoting space sustainability and accessibility. As a student society, the aim of this research is to demonstrate the viability of a drag sail technology in the absence of large monetary investment.a In this article, the studies on the structure, material and Hold-Down and Release Mechanism (HDRM) of the drag sail system are evaluated and briefly discussed. The discussion starts by illustrating the 7m2 quasi-rhombic drag sail that will deploy to increase the satellite's atmospheric drag and allow the spacecraft to lose altitude and re-enter the atmosphere. Various aspects of the geometry and folding technique used to fit the drag sail on the CubeSat are analysed. Phenomena of material degradation such as thermal and oxygen degradation have been accounted for in the design to mitigate their effect over the duration of the mission. Tape spring booms coiled around a spool will release the drag sail from its folded state maintained throughout the mission. These have been dimensioned through a mathematical model in order to provide optimum deployment dynamics for the drag sail. The paper describes also how a simple and economic nichrome burn-wire HDRM has been integrated with the drag sail design to trigger the release sequence of the cover doors and the drag sail itself

Migdal effect and photon Bremsstrahlung: improving the sensitivity to light dark matter of liquid argon experiments

The search for dark matter weakly interacting massive particles with noble liquids has probed masses down and below a GeV/c^2. The ultimate limit is represented by the experimental threshold on the energy transfer to the nuclear recoil. Currently, the experimental sensitivity has reached a threshold equivalent to a few ionization electrons. In these conditions, the contribution of a Bremsstrahlung photon or a so-called Migdal electron due to the sudden acceleration of a nucleus after a collision might be sizable. In the present work, we use a Bayesian approach to study how these effects can be exploited in experiments based on liquid argon detectors. In particular, taking inspiration from the DarkSide-50 public spectra, we develop a simulated experiment to show how the Migdal electron and the Bremsstrahlung photon allow to push the experimental sensitivity down to masses of 0.1 GeV/c^2, extending the search region for dark matter particles of previous results. For these masses we estimate the effect of the Earth shielding that, for strongly interacting dark matter, makes any detector blind. Finally, we show how the sensitivity scales for higher exposure.Comment: 30 pages, 13 figures, 2 table

Misura e forma di architetture del passato: il ponte di Luigi Vanvitelli a Eboli

The paper highlights the potential of the infographic representation addressed to the digital reconstruction of architectures of the past, of which the drawing is the only historical evidence. The subject of investigation is a bridge designed by Luigi Vanvitelli on a stretch of the Sele river, in Campania, that was almost completely destroyed during the second World War and then rebuilt with features decidedly distant from the original solution. Through an archival research, they were found the autographs drawings of the original bridge and were compared with the survey of the current one, in order to ascertain what had remained unchanged of the vanvitellian architecture. Through digital modeling techniques, finally, the bridge was virtually rebuilt, with the intention of being able to return its forms, measures and material qualities