Structure and Dynamics of amorphous Silica Surfaces

We use molecular dynamics computer simulations to study the equilibrium properties of the surface of amorphous silica. Two types of geometries are investigated: i) clusters with different diameters (13.5\AA, 19\AA, and 26.5\AA) and ii) a thin film with thickness 29\AA. We find that the shape of the clusters is independent of temperature and that it becomes more spherical with increasing size. The surface energy is in qualitative agreement with the experimental value for the surface tension. The density distribution function shows a small peak just below the surface, the origin of which is traced back to a local chemical ordering at the surface. Close to the surface the partial radial distribution functions as well as the distributions of the bond-bond angles show features which are not observed in the interior of the systems. By calculating the distribution of the length of the Si-O rings we can show that these additional features are related to the presence of two-membered rings at the surface. The surface density of these structures is around 0.6/nm^2 in good agreement with experimental estimates. From the behavior of the mean-squared displacement at low temperatures we conclude that at the surface the cage of the particles is larger than the one in the bulk. Close to the surface the diffusion constant is somewhat larger than the one in the bulk and with decreasing temperature the relative difference grows. The total vibrational density of states at the surface is similar to the one in the bulk. However, if only the one for the silicon atoms is considered, significant differences are found.Comment: 30 pages of Latex, 16 figure

Taphonomy and the Reconstruction of Tomb Architecture and Mortuary Practices at Protohistoric Crustumerium (Rome)

This paper takes into account all factors that affected the preservation of tombs and their inventories in the burial grounds of ancient Crustumerium, a Latin settlement 13 km north of Rome, inhabited between the 9th and 5th c. BC. Its aim is to highlight the combined effect of two main processes;a) the severe erosion of the topsoil and the underlying soft volcanic bedrock caused by centuries of ploughing that has profoundly affected the preservation of tomb architecture, i.e. landscape processes;b) post-depositional processes affecting organic materials (wood, textiles, human bone) and inorganic materials (pottery, metal) in the tombs as a result of flooding, collapse and the acidity of the soil, i.e. taphonomy

NEDOVRŠENA SMRTONOSNA TREPANACIJA UTVRĐENA NA KREMIRANIM OSTACIMA (RIM, ITALIJA, II. ST.)

Background: An original case of incomplete (and reasonably fatal) human trepanation is described in this short paper. The diagnosis was made on the cremated remains of a young adult individual who died in Rome, Italy during the 2nd century AD. Clinical Presentation: The trepanation was incomplete, as death occurred quickly due to vascular lesions, according to the anatomic analysis of the bone piece. Comparable trepanation from Roman times are described and related to this case. Conclusion: Even if archaeological, this case highlights the possibility of such a diagnosis on post-fire fragmented bones. Very suggestive lesions of section are of great interest for the history of such a practice during classical Antiquity. Lastly, from a medical and forensic point of view, such a diagnosis may be of interest during any identification process and research for a cause of death during anthropological analyses.Uvod: Ovaj kratki rad opisuje izvorni slučaj nedovršene, fatalne trepanacije. Dijagnoza trepanacije postavljena je temeljem pregleda kremiranih ostataka mlade odrasle osobe umrle u II. stoljeću u Rimu. Klinička slika: Anatomskom analizom kostiju utvrđena je nedovršena trepanacija, vjerojatno zbog smrti koja je nastupila netom nakon početka zahvata kao posljedica oštećenja krvožilja. Uz to, prikazani nalaz uspoređuje se sa sličnim slučajevima trepanacije iz rimskog razdoblja. Zaključak: Iako temeljen na arheološkim ostacima, ovaj slučaj ističe mogućnost dijagnosticiranja trepanacije iz kremiranih i fragmetniranih koštanih ostataka. Sugestivna oštećenja utvrđena na koštanom materijalu od značajnog su interesa za povijest trepanacije u klasičnoj antici. Također, ovakav slučaj može biti od interesa medicinskoj struci tijekom identifikacijskih procesa i antropološkog utvrđivanja uzroka smrti iz koštanih ulomaka

Leg rings impact the diving performance of a foot-propelled diver

Leg rings are frequently used to mark aquatic birds in order to identify individuals, and study population dynamics and migration patterns, with the proviso being that the rings should not affect the birds. The effects of tags and rings are of particular interest in diving birds because any change in body shape could impact swimming efficiency and costs, as water is almost a thousand times denser than air. We attached tri-axial accelerometers to both ringed and unringed breeding Imperial Shags Leucocarbo atriceps to assess dive performance based on descent angle, descent rate, power stroke rate, power stroke peak acceleration amplitude and Vectorial Dynamic Body Acceleration (VeDBA) as a proxy for energy expenditure. Ringed birds, especially females, had a higher foot-stroke amplitude than unringed animals. In addition, the overall efficiency of the ringed individuals, as expressed by the descent rate per unit VeDBA, was compromised (by 3.5% in females and 4.3% in males) compared with unringed birds. We conclude that leg rings change the diving performance of Imperial Shags, although the effect is small and may not affect reproductive success. However, given that birds are typically ringed for life, we urge researchers to be particularly careful about the potential cumulative effect of attaching leg rings to foot-propelled diving species.Fil: Gómez Laich, Agustina Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Pantano, Carolina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Wilson, Rory P. Swansea University. College Of Sciences. Departament Of Biosciences; Reino UnidoFil: Svagelj, Walter Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Yoda, Ken. Nagoya University; JapónFil: Gunner, Richard. Swansea University. College Of Sciences. Departament Of Biosciences; Reino UnidoFil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentin

Silicon oxycarbide glass for the immobilisation of irradiated graphite waste

© 2015 Elsevier B.V. Silicon oxycarbide glass has been investigated as a potential immobilisation medium for irradiated graphite waste from nuclear power generation. The glass was synthesised via sol-gel techniques using alkoxysilane precursors. Attempts to produce a wasteform via conventional sintering were unsuccessful, but dense wasteforms were achieved by spark plasma sintering (SPS). Microstructural investigations showed that the addition of graphite to the glass did not alter the structure of the matrix; no reaction between the graphite and the glass matrix was observed. Silicon oxycarbide glass is a viable candidate for encapsulation of graphite waste prior to disposal

Clinical Features, Cardiovascular Risk Profile, and Therapeutic Trajectories of Patients with Type 2 Diabetes Candidate for Oral Semaglutide Therapy in the Italian Specialist Care

Introduction: This study aimed to address therapeutic inertia in the management of type 2 diabetes (T2D) by investigating the potential of early treatment with oral semaglutide. Methods: A cross-sectional survey was conducted between October 2021 and April 2022 among specialists treating individuals with T2D. A scientific committee designed a data collection form covering demographics, cardiovascular risk, glucose control metrics, ongoing therapies, and physician judgments on treatment appropriateness. Participants completed anonymous patient questionnaires reflecting routine clinical encounters. The preferred therapeutic regimen for each patient was also identified. Results: The analysis was conducted on 4449 patients initiating oral semaglutide. The population had a relatively short disease duration (42%  60% of patients, and more often than sitagliptin or empagliflozin. Conclusion: The study supports the potential of early implementation of oral semaglutide as a strategy to overcome therapeutic inertia and enhance T2D management

Measurement of the mass difference m(D-s(+))-m(D+) at CDF II

We present a measurement of the mass difference m(D-s(+))-m(D+), where both the D-s(+) and D+ are reconstructed in the phipi(+) decay channel. This measurement uses 11.6 pb(-1) of data collected by CDF II using the new displaced-track trigger. The mass difference is found to be m(D-s(+))-m(D+)=99.41+/-0.38(stat)+/-0.21(syst) MeV/c(2)

Organizzazione funeraria e struttura sociale degli inumati di Casal Bertone (Roma, I-III sec. d.C.)

Gli scavi archeologici preventivi alla realizzazione della Ferrovia ad Alta Velocità, hanno portato in luce, nel quartiere romano di Casal Bertone, un vasto impianto produttivo, pertinente ad una fullonica, e tre aree sepolcrali, indicate come: mausoleo, necropoli ed Area Q. Per tentare di ricostruire le condizioni di salute e la qualità di vita delle comunità di riferimento, sono stati rilevati, sui 199 inumati recuperati, i seguenti indicatori: le patologie orali, gli indicatori di stress aspecifici, i marcatori muscolo-scheletrici e ligamentari, i traumi, le fratture e l’osteoartrosi. I risultati ottenuti evidenziano che le condizioni di vita del campione del mausoleo fossero migliori di quelle della necropoli e dell’Area Q. Inoltre, condividendo lo stesso monumento sepolcrale, la comunità potrebbe far riferimento ad un collegium. Per il campione della necropoli, come indicato soprattutto dai markers occupazionali, si può ipotizzare l’impiego nelle attività del vicino impianto produttivo.The archaeological excavations for the realization of the High Speed ​​Railway, have brought to light, in the Roman district of Casal Bertone, a large production system relevant to a fullonica and three burial areas referred to as mausoleum, necropolis and Area Q. To try to rebuild the health conditions and quality of life of the communities of reference, we examined the following indicators on the 199 recovered dead: oral diseases, non-specific stress indicators, musculoskeletal and ligament markers, traumas, fractures and osteoarthritis. The results show that the living conditions of the people buried in the mausoleum were better than those of the people buried in the necropolis and in the Area Q. Moreover, sharing the same sepulchral monument, the community could refer to a collegium. For the necropolis sample, we can hypothesize the use of the reference community in the activities of the nearby production system