Searching for the Nuclear Liquid-Gas Phase Transition in Au + Au Collisions at 35 MeV/nucleon

Within the framework of Classical Molecular Dynamics, we study the collision Au + Au at an incident energy of 35 MeV/nucleon. It is found that the system shows a critical behaviour at peripheral impact parameters, revealed through the analysis of conditional moments of charge distributions, Campi Scatter Plot, and the occurrence of large fluctuations in the region of the Campi plot where this critical behaviour is expected. When applying the experimental filters of the MULTICS-MINIBALL apparatus, it is found that criticality signals can be hidden due to the inefficiency of the experimental apparatus. The signals are then recovered by identifying semi-peripheral and peripheral collisions looking to the velocity distribution of the largest fragment, then by selecting the most complete events.Comment: RevTex file, 21 pages + 19 figures available upon request from [email protected]

Circumstantial Evidence for a Critical Behavior in Peripheral Au + Au Collisions at 35 MeV/nucleon

The fragmentation resulting from peripheral Au + Au collisions at an incident energy of E = 35 MeV/nucleon is investigated. A power-law charge distribution, $A^{-\tau}$ with $\tau \approx 2.2$, and an intermittency signal are observed for events selected in the region of the Campi scatter plot where "critical" behavior is expected.Comment: 11 pages, RevTex file, 4 postscript figures available upon request from [email protected]

Language support for immigrant children: a study of state schools in the UK and US

In recent decades, immigrants, refugees and asylum seekers have sought a new way of life in large numbers, often leaving their countries of origin behind in search of places that offer a better way of life. The purpose of this study was to investigate how elementary and middle school students in state schools in Reading, England (primarily speakers of Asian languages), and Richmond, Virginia (primarily speakers of Spanish), were supported academically, when most children’s first language was not English. The authors were interested in exploring whether or not there were cultural or structural differences in the way each country helped or hindered these students as they progressed through the school systems. Three UK schools in a district of approximately 100,000 and three US schools in a district of approximately 250,000 were the focus of this exploration from 2000 to 2003. Findings indicated that there were cultural and legislative differences and similarities. Teachers and administrators in both countries attempted to provide services with limited and sometimes diminishing resources. Community support varied based on resources, attitudes toward various ethnic groups, and the coping strategies adopted by these groups in their new environments. Marked differences appeared with regard to the manner in which assessments took place and how the results were made available to the public

On Polynomial Stability of Coupled Partial Differential Equations in 1D

We study the well-posedness and asymptotic behaviour of selected PDE-PDE and PDE-ODE systems on one-dimensional spatial domains, namely a boundary coupled wave-heat system and a wave equation with a dynamic boundary condition. We prove well-posedness of the models and derive rational decay rates for the energy using an approach where the coupled systems are formulated as feedback interconnections of impedance passive regular linear systems.Comment: 12 pages, 1 figure, accepted for publication in the Proceedings of "Semigroups of Operators: Theory and Applications", Kazimierz Dolny, Poland, October 201

Autophagy Induction Is a Tor- and Tp53-Independent Cell Survival Response in a Zebrafish Model of Disrupted Ribosome Biogenesis

Ribosome biogenesis underpins cell growth and division. Disruptions in ribosome biogenesis and translation initiation are deleterious to development and underlie a spectrum of diseases known collectively as ribosomopathies. Here, we describe a novel zebrafish mutant, titania (tti(s450)), which harbours a recessive lethal mutation in pwp2h, a gene encoding a protein component of the small subunit processome. The biochemical impacts of this lesion are decreased production of mature 18S rRNA molecules, activation of Tp53, and impaired ribosome biogenesis. In tti(s450), the growth of the endodermal organs, eyes, brain, and craniofacial structures is severely arrested and autophagy is up-regulated, allowing intestinal epithelial cells to evade cell death. Inhibiting autophagy in tti(s450) larvae markedly reduces their lifespan. Somewhat surprisingly, autophagy induction in tti(s450) larvae is independent of the state of the Tor pathway and proceeds unabated in Tp53-mutant larvae. These data demonstrate that autophagy is a survival mechanism invoked in response to ribosomal stress. This response may be of relevance to therapeutic strategies aimed at killing cancer cells by targeting ribosome biogenesis. In certain contexts, these treatments may promote autophagy and contribute to cancer cells evading cell death.This research was funded by the National Health and Medical Research Council of Australia through Project grant 433614 (JKH), Program grant 487922 (JKH), a Senior Research Fellowship (JKH), and a Howard Florey Centenary Fellowship (HV). Operational Infrastructure Support was provided by the Victorian Government, Australia. Additional support was from Australian Research Council grant DP0346823 (GJL); NIH grant DK060322 (DYRS); and CDMRP, Department of Defense, USA W81XWH-10-1-0854 (KCE)

A comparative thematic review of vocational leadership literature from the USA, Great Britain and Australia

Vocational education and its leadership is an important sphere of economic activity worldwide and is being impacted by several trends including: the increasing significance and centrality of skills development in today’s economies; economic trends associated with globalisation (internationalisation of education and emergence of global labour markets); and demographic trends resulting in ageing populations and workforces. Leadership in vocational education contexts is crucial to the economic success of this sector. The aim of this paper is to provide a comparative thematic review of the research and literature on leadership in vocational education between the USA, Great Britain and Australia posed by the research question, ‘What are the key leadership issues facing vocational education and training sectors in the USA, Great Britain and Australia?’ This study contributes to the research and literature by identifying key impact factors for vocational education leadership in these nations over the last 13 years. Results from the comparative review established the following three key issues: a concern over equity and diversity; the importance of change management; and leadership skills and their development. Although leadership competencies are the subject of some debate there appears to be a broad consensus that leaders are developed not only by formal courses, but more importantly by on-the-job experiential learning. The future development of leaders within vocational education is discussed in relation to the implications for policy and practice, and suggestions for future research are provided

Clinical field-strength MRI of amyloid plaques induced by low-level cholesterol feeding in rabbits

Two significant barriers have limited the development of effective treatment of Alzheimer's disease. First, for many cases the aetiology is unknown and likely multi-factorial. Among these factors, hypercholesterolemia is a known risk predictor and has been linked to the formation of β-amyloid plaques, a pathological hallmark this disease. Second, standardized diagnostic tools are unable to definitively diagnose this disease prior to death; hence new diagnostic tools are urgently needed. Magnetic resonance imaging (MRI) using high field-strength scanners has shown promise for direct visualization of β-amyloid plaques, allowing in vivo longitudinal tracking of disease progression in mouse models. Here, we present a new rabbit model for studying the relationship between cholesterol and Alzheimer's disease development and new tools for direct visualization of β-amyloid plaques using clinical field-strength MRI. New Zealand white rabbits were fed either a low-level (0.125–0.25% w/w) cholesterol diet (n = 5) or normal chow (n = 4) for 27 months. High-resolution (66 × 66 × 100 µm3; scan time = 96 min) ex vivo MRI of brains was performed using a 3-Tesla (T) MR scanner interfaced with customized gradient and radiofrequency coils. β-Amyloid-42 immunostaining and Prussian blue iron staining were performed on brain sections and MR and histological images were manually registered. MRI revealed distinct signal voids throughout the brains of cholesterol-fed rabbits, whereas minimal voids were seen in control rabbit brains. These voids corresponded directly to small clusters of extracellular β-amyloid-positive plaques, which were consistently identified as iron-loaded (the presumed source of MR contrast). Plaques were typically located in the hippocampus, parahippocampal gyrus, striatum, hypothalamus and thalamus. Quantitative analysis of the number of histologically positive β-amyloid plaques (P < 0.0001) and MR-positive signal voids (P < 0.05) found in cholesterol-fed and control rabbit brains corroborated our qualitative observations. In conclusion, long-term, low-level cholesterol feeding was sufficient to promote the formation of extracellular β-amyloid plaque formation in rabbits, supporting the integral role of cholesterol in the aetiology of Alzheimer's disease. We also present the first evidence that MRI is capable of detecting iron-associated β-amyloid plaques in a rabbit model of Alzheimer's disease and have advanced the sensitivity of MRI for plaque detection to a new level, allowing clinical field-strength scanners to be employed. We believe extension of these technologies to an in vivo setting in rabbits is feasible and that our results support future work exploring the role of MRI as a leading imaging tool for this debilitating and life-threatening disease

Full Circle or Spiralling Out of Control?: State Violence and the Control of Urbanisation in Papua New Guinea

There is an administrative reluctance to recognise the permanency of urban settlement in Papua New Guinea. This reluctance, evident since the 1960s, has been characteristic of both the colonial and post-colonial administrations. Opposition to some facets of urbanisation continues today, despite growing population and land pressures in most rural areas and real problems of landlessness emerging in particular rural areas. Colonial control of urban populations has been replicated in contemporary times, often in more draconian form. Eviction of urban settlers has been tied to issues of crime and urban respectability, and lingering perceptions that Melanesians should be rural residents. The growth of informal settlements and urbanisation are not seen as issues of urban planning, nor is the context of urban migration linked to socioeconomic inequality, hence other forms of urban policy are largely absent. Strengthening alliances between land-owners and the state (especially police and provincial administrations) have thus emphasised intraurban inequality and hampered national development

Biophysical Characterization and Membrane Interaction of the Two Fusion Loops of Glycoprotein B from Herpes Simplex Type I Virus

The molecular mechanism of entry of herpesviruses requires a multicomponent fusion system. Cell invasion by Herpes simplex virus (HSV) requires four virally encoded glycoproteins: namely gD, gB and gH/gL. The role of gB has remained elusive until recently when the crystal structure of HSV-1 gB became available and the fusion potential of gB was clearly demonstrated. Although much information on gB structure/function relationship has been gathered in recent years, the elucidation of the nature of the fine interactions between gB fusion loops and the membrane bilayer may help to understand the precise molecular mechanism behind herpesvirus-host cell membrane fusion. Here, we report the first biophysical study on the two fusion peptides of gB, with a particular focus on the effects determined by both peptides on lipid bilayers of various compositions. The two fusion loops constitute a structural subdomain wherein key hydrophobic amino acids form a ridge that is supported on both sides by charged residues. When used together the two fusion loops have the ability to significantly destabilize the target membrane bilayer, notwithstanding their low bilayer penetration when used separately. These data support the model of gB fusion loops insertion into cholesterol enriched membranes