Universality of Cluster Dynamics

We have studied the kinetics of cluster formation for dynamical systems of dimensions up to $n=8$ interacting through elastic collisions or coalescence. These systems could serve as possible models for gas kinetics, polymerization and self-assembly. In the case of elastic collisions, we found that the cluster size probability distribution undergoes a phase transition at a critical time which can be predicted from the average time between collisions. This enables forecasting of rare events based on limited statistical sampling of the collision dynamics over short time windows. The analysis was extended to L$^p$-normed spaces ($p=1,...,\infty$) to allow for some amount of interpenetration or volume exclusion. The results for the elastic collisions are consistent with previously published low-dimensional results in that a power law is observed for the empirical cluster size distribution at the critical time. We found that the same power law also exists for all dimensions $n=2,...,8$, 2D L$^p$ norms, and even for coalescing collisions in 2D. This broad universality in behavior may be indicative of a more fundamental process governing the growth of clusters

Fibre laser treatment of beta TNZT titanium alloys for load-bearing implant applications: Effects of surface physical and chemical features on mesenchymal stem cell response and Staphylococcus aureus bacterial attachment

A mismatch in bone and implant elastic modulus can lead to aseptic loosening and ultimately implant failure. Selective elemental composition of titanium (Ti) alloys coupled with surface treatment can be used to improve osseointegration and reduce bacterial adhesion. The biocompatibility and antibacterial properties of Ti-35Nb-7Zr-6Ta (TNZT) using fibre laser surface treatment were assessed in this work, due to its excellent material properties (low Young’s modulus and non-toxicity) and the promising attributes of fibre laser treatment (very fast, non-contact, clean and only causes changes in surface without altering the bulk composition/microstructure). The TNZT surfaces in this study were treated in a high speed regime, specifically 100 and 200 mm/s, (or 6 and 12 m/min). Surface roughness and topography (WLI and SEM), chemical composition (SEM-EDX), microstructure (XRD) and chemistry (XPS) were investigated. The biocompatibility of the laser treated surfaces was evaluated using mesenchymal stem cells (MSCs) cultured in vitro at various time points to assess cell attachment (6, 24 and 48 h), proliferation (3, 7 and 14 days) and differentiation (7, 14 and 21 days). Antibacterial performance was also evaluated using Staphylococcus aureus (S. aureus) and Live/Dead staining. Sample groups included untreated base metal (BM), laser treated at 100 mm/s (LT100) and 200 mm/s (LT200). The results demonstrated that laser surface treatment creates a rougher (Ra value of BM is 199 nm, LT100 is 256 nm and LT200 is 232 nm), spiky surface (Rsk > 0 and Rku > 3) with homogenous elemental distribution and decreasing peak-to-peak distance between ripples (0.63 to 0.315 m) as the scanning speed increases (p < 0.05), generating a surface with distinct micron and nano scale features. The improvement in cell spreading, formation of bone-like nodules (only seen on the laser treated samples) and subsequent four-fold reduction in bacterial attachment (p < 0.001) can be attributed to the features created through fibre laser treatment, making it an excellent choice for load bearing implant applications. Last but not least, the presence of TiN in the outermost surface oxide might also account for the improved biocompatibility and antibacterial performances of TNZT

Observations sur la langue dans les lettres adressées a Š. Ljubić

Dans le présent article sont examinées certaines questions portant sur la langue et l\u27orthographe telles qu\u27on peut les constater dans les lettres faisant partie du legs de Š. Ljubić conservé dans les Archives historiques de Zadar. Leur date se situe autour de la moitié du 19e siècle. Les auteurs de ces lettres sont I. Kukuljević Sakcinski, A. Torkvato Brlić, B. Petranović et Š. Starčević. Donc, un Zagrébien, un autre provenant de Slavonie et deux Dalmates, dont l\u27un était Serbe et l\u27autre Croate. De cette manière dans ces lettres sont représentées toutes les couches et structures et les principaux courants de la Croatie avec leurs vues sur la langue littéraire

Personality traits and environmental choices: On the search for understanding

In this paper we hypothesize that individuals will choose among alternative courses of action for power generation from wind farms according to their personality profiles. Through a factor analysis we found that certain characteristics of personality do indeed have an effect on environmental choice. The study involves an extensive survey based on the Big Five Traits model to find a pattern of choice that will help to better understand environmental decisions and be useful for policy makers to identify target groups and preview reactions to different courses of action. The research is potentially useful for the better preparation and design of publicity material, awareness raising campaigns and information provision for complex or unpopular policies affecting the environment or in environmental education in general. This research is especially interested in shedding some light on how personality is involved in the processes of environmental decision making, despite the limitations of the present study

Clinical Practice Guideline for the Evaluation of Fever and Infection in Older Adult Residents of Long-Term Care Facilities: 2008 Update by the Infectious Diseases Society of America

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65801/1/j.1532-5415.2009.02175.x.pd