759 research outputs found
Cyclic Loading Response of Cohesive Soils Using A Bounding Surface Plasticity Model
The concept of the bounding surface in plasticity theory has been used to develop a general three-dimensional constitutive model for cohesive soils within the framework of critical state soil mechanics. The present work focuses on the response of the above model under cyclic loading conditions. It is shown mainly qualitatively and partially quantitatively, that the model predicts in detailed form a material response which does agree with observed experimental behavior under undrained and drained loading conditions at any overconsolidation ratio and for different cyclic deviatoric stress amplitudes
Decoupling Simulated Annealing From Massive Multiplayer Online Role-Playing Games in RAID
End-users agree that compact technology are an interesting new topic in the field of electri- cal engineering, and physicists concur. In fact, few futurists would disagree with the deploy- ment of Byzantine fault tolerance, demonstrates the structured importance of cryptography. We construct a novel algorithm for the simulation of write-ahead logging (JDL), validating that Byzantine fault tolerance can be made peer-to- peer, classical, and stable. It is often an important mission but is supported by previous work in the field
Flat-band ferromagnetism induced by off-site repulsions
Density matrix renormalization group method is used to analyze how the
nearest-neighbor repulsion V added to the Hubbard model on 1D triangular
lattice and a railway trestle (t-t') model will affect the electron-correlation
dominated ferromagnetism arising from the interference (frustration). Obtained
phase diagram shows that there is a region in smaller-t' side where the
critical on-site repulsion above which the system becomes ferromagnetic is
reduced when the off-site repulsion is introduced.Comment: 4 pages, RevTex, 6 figures in Postscript, to be published in Phys.
Rev.
Tight-binding study of high-pressure phase transitions in titanium: alpha to omega and beyond
We use a tight-binding total energy method, with parameters determined from a
fit to first-principles calculations, to examine the newly discovered gamma
phase of titanium. Our parameters were adjusted to accurately describe the
alpha Ti-omega Ti phase transition, which is misplaced by density functional
calculations. We find a transition from omega Ti to gamma Ti at 102 GPa, in
good agreement with the experimental value of 116 GPa. Our results suggest that
current density functional calculations will not reproduce the omega Ti-gamma
Ti phase transition, but will instead predict a transition from omega Ti to the
bcc beta Ti phase.Comment: 3 encapsulated Postscript figures, submitted to Phyical Review
Letter
Embedding effective depression care: using theory for primary care organisational and systems change
Background: depression and related disorders represent a significant part of general practitioners (GPs) daily work. Implementing the evidence about what works for depression care into routine practice presents a challenge for researchers and service designers. The emerging consensus is that the transfer of efficacious interventions into routine practice is strongly linked to how well the interventions are based upon theory and take into account the contextual factors of the setting into which they are to be transferred. We set out to develop a conceptual framework to guide change and the implementation of best practice depression care in the primary care setting.Methods: we used a mixed method, observational approach to gather data about routine depression care in a range of primary care settings via: audit of electronic health records; observation of routine clinical care; and structured, facilitated whole of organisation meetings. Audit data were summarised using simple descriptive statistics. Observational data were collected using field notes. Organisational meetings were audio taped and transcribed. All the data sets were grouped, by organisation, and considered as a whole case. Normalisation Process Theory (NPT) was identified as an analytical theory to guide the conceptual framework development.Results: five privately owned primary care organisations (general practices) and one community health centre took part over the course of 18 months. We successfully developed a conceptual framework for implementing an effective model of depression care based on the four constructs of NPT: coherence, which proposes that depression work requires the conceptualisation of boundaries of who is depressed and who is not depressed and techniques for dealing with diffuseness; cognitive participation, which proposes that depression work requires engagement with a shared set of techniques that deal with depression as a health problem; collective action, which proposes that agreement is reached about how care is organised; and reflexive monitoring, which proposes that depression work requires agreement about how depression work will be monitored at the patient and practice level. We describe how these constructs can be used to guide the design and implementation of effective depression care in a way that can take account of contextual differences.Conclusions: ideas about what is required for an effective model and system of depression care in primary care need to be accompanied by theoretically informed frameworks that consider how these can be implemented. The conceptual framework we have presented can be used to guide organisational and system change to develop common language around each construct between policy makers, service users, professionals, and researchers. This shared understanding across groups is fundamental to the effective implementation of change in primary care for depressio
Instability of scale-free networks under node-breaking avalanches
The instability introduced in a large scale-free network by the triggering of
node-breaking avalanches is analyzed using the fiber-bundle model as conceptual
framework. We found, by measuring the size of the giant component, the
avalanche size distribution and other quantities, the existence of an abrupt
transition. This test of strength for complex networks like Internet is more
stringent than others recently considered like the random removal of nodes,
analyzed within the framework of percolation theory. Finally, we discuss the
possible implications of our results and their relevance in forecasting
cascading failures in scale-free networks.Comment: 4 pages, 4 figures, final version to be published in Europhys. Let
Cryptic diversity in the North American Dromochorus tiger beetles (Coleoptera: Carabidae: Cicindelinae): a congruence-based method for species discovery
A fundamental problem in biodiversity science is determining the number of species in any taxon, and there is a growing awareness that cryptic diversity contributes to this problem – even in well-studied groups. Discovering cryptic species requires several lines of evidence to elucidate congruent patterns across data-types, and distinguish unrecognized species. Tiger beetles are among the most well-studied insect groups; yet few new North American species have been described since the mid-20th century, suggesting that that the number of morphologically distinct species is reaching an asymptote. We explore the possibility that more species exist in the fauna as cryptic species, by analysing a broad geographic sample of all species in the genus Dromochorus. We employ a ‘taxonomic congruence’ approach, where we first generate species hypotheses from patterns of reciprocal monophyly across the mitochondrial and nuclear datasets, and test these hypotheses through congruence with population structure, morphological measures and ecological divergence. We find broad congruence that supports eight species of Dromochorus, more than doubling the known diversity. We also validate a previously ambiguous taxon, and re-describe previously named species. Lastly, we identify new diagnostic morphological characters, include an updated dichotomous key and provide updated natural history/ecological characteristics for the genus and individual species
Community views on ‘Can perinatal services safely identify Aboriginal and Torres Strait Islander parents experiencing complex trauma?’
Family and extended kinship systems which nurture healthy, happy children are central to Aboriginal and Torres Strait Islander cultures. Since colonisation, Aboriginal and Torres Strait Islander communities have been impacted by intergenerational cycles of trauma, stemming from colonial violence, genocidal policies and discrimination, including the forced removal of children from their families. Becoming a parent offers a unique life-course opportunity for trauma recovery and preventing intergenerational trauma. However, identifying or ‘recognising’ complex trauma carries significant risk of harm for Aboriginal and Torres Strait Islander parents due to reactive prenatal child protection involvement potentially compounding experiences of trauma, and limited benefits due to lack of culturally appropriate support. The Aboriginal-led participatory Healing the Past by Nurturing the Future project aims to co-design safe, accessible and feasible perinatal awareness, recognition, assessment and support strategies for Aboriginal and Torres Strait Islander parents experiencing complex trauma. This paper presents views of 38 workshop participants to determine prerequisites for ensuring benefits outweigh risks of assessment to safely recognise parents experiencing complex trauma, consistent with screening criteria. Six essential elements were identified from thematic analysis: high-quality holistic care; cultural, social and emotional safety; empowerment, choice and control; flexible person-centred approaches; trusting relationships; and sensitive, skilled communication
Determining weight-bearing tissue condition using peak reactive hyperemia response trend and ultrasonographic features: implications for pressure ulcer prevention
Frequent repositioning is important to prevent pressure ulcer (PU) development, by relieving pressure and recovering damages on skin areas induced by repetitive loading. Although repositioning is the gold standard to prevent PU, there is currently no strategy for determining tissue condition under preventive approaches. In this study, the peak reactive hyperemia (RH) trends and ultrasonographic (US) features are compared with the tissue condition under histopathological examination to determine the potential use of these features in determining the tissue condition noninvasively. Twenty-one male Sprague–Dawley rats (seven per group), with body weight of 385–485 g, were categorized into three groups and subjected to different recovery times, each with three repetitive loading cycles at skin tissues above of right trochanter area. The first, second, and third groups were subjected to short (3 minutes), moderate (10 minutes), and prolonged (40 minutes) recovery, respectively, while applying fixed loading time and pressure (10 minutes and 50 mmHg, respectively), to provide different degree of recovery and tissue conditions (tissue damage and tissue recovery). Peak RH was measured in the three cycles to determine RH trend (increasing, decreasing, and inconsistent). All rat tissues were evaluated using ultrasound at pre- and post-experiment and rated by two raters to categorize the severity of tissue changes (no, mild, moderate, and severe). The tissue condition was also evaluated using histopathological examination to distinguish between normal and abnormal tissues. Most of the samples with increasing RH trend is related to abnormal tissue (71%); while inconsistent RH trends is more related to normal tissue (82%). There is no relationship between the tissue conditions evaluated under ultrasonographic and histopathological examination. Peak RH trend over repetitive loading may serve as a new feature for determining the tissue condition that leading to pressure ulcer
- …