bluuebunny/crossref_metadata_2025_split huggingface dataset:
The natural history of early-onset dementia: the Artemis Project
Authors: Atkins Emily R , Bulsara Max K , Panegyres Peter K 
Published: October 2012

ObjectivesThe natural history of early-onset Alzheimer's disease (AD) and fronto-temporal dementia (FTD) remains to be described in detail. We seek to describe the natural history of early onset AD and FTD in terms of changes in cognitive assessment and staging, medical history and survival.DesignLongitudinal prospective cohort analysis.SettingNeurodegenerative disorders research clinic.ParticipantsIn total, 155 consecutive patients with clinically confirmed sporadic early-onset AD or FTD at a neurodegenerative disorders research clinic in Subiaco, Western Australia (The Artemis Project).MethodsA detailed history was recorded from the patients at baseline, including education, family history and medical history. Mini-mental state exam (MMSE), Global Deterioration Scale (GDS) and total functional capacity (TFC) were determined at each visit from 1994 until 2011. Kaplan-Meier survival analysis was performed.ResultsPatients with FTD were more likely to have a family history of dementia (p=0.026), to develop at least one cerebrovascular risk factor (p=0.003), manifest depression (Fisher's exact p=0.007) and to die during the follow-up period (Pearson χ28.97, p=0.003). Kaplan-Meier survival estimates revealed a highly significant difference in the proportion of patients surviving the follow-up period (log rank 7.25, p=0.007) with FTD patients experiencing poorer survival than those with AD. The mean MMSE and TFC were consistently lower in those with FTD compared with those with AD over a decade of follow-up; mean GDS was consistently higher in those with FTD over the follow-up period.ConclusionsWe believe that the difference in survival in patients with AD and FTD in our cohort might relate to the development of one or more cerebrovascular risk factors in FTD patients and the severity of the underlying pathology.
Use of in situ simulation and human factors engineering to assess and improve emergency department clinical systems for timely telemetry-based detection of life-threatening arrhythmias
Authors: Kobayashi Leo , Parchuri Ramakrishna , Gardiner Fenwick G , Paolucci Gino A , Tomaselli Nicole M , Al-Rasheed Rakan S , Bertsch Karina S , Devine Jeffrey , Boss Robert M , Gibbs Frantz J , Goldlust Eric , Monti James E , O'Hearn Brian , Portelli David C , Siegel Nathan A , Hemendinger David , Jay Gregory D 
Published: October 2012

Background and objectivesMedical simulation and human factors engineering (HFE) may help investigate and improve clinical telemetry systems. Investigators sought to (1) determine the baseline performance characteristics of an Emergency Department (ED) telemetry system implementation at detecting simulated arrhythmias and (2) improve system performance through HFE-based intervention.MethodsThe prospective study was conducted in a regional referral ED over three 2-week periods from 2010 to 2012. Subjects were clinical providers working at the time of unannounced simulation sessions. Three-minute episodes of sinus bradycardia (SB) and of ventricular tachycardia (VT) were simulated. An experimental HFE-based multi-element intervention was developed to (1) improve system accessibility, (2) increase system relevance and utility for ED clinical practice and (3) establish organisational processes for system maintenance and user base cultivation. The primary outcome variable was overall simulated arrhythmia detection. Pre-intervention system characterisation, post-intervention end-user feedback and real-world correlates of system performance were secondary outcome measures.ResultsBaseline HFE assessment revealed limited accessibility, suboptimal usability, poor utility and general neglect of the telemetry system; one simulated VT episode (5%) was detected during 20 pre-intervention sessions. Systems testing during intervention implementation recorded detection of 4 out of 10 arrhythmia simulations (p=0.03). Twenty post-intervention sessions revealed more VT detections (8 of 10) than SB detections (3 of 10) for a 55% overall simulated arrhythmia detection rate (p=0.001).ConclusionsExperimental investigations helped reveal and mitigate weaknesses in an ED clinical telemetry system implementation. In situ simulation and HFE methodologies can facilitate the assessment and abatement of patient safety hazards in healthcare environments.
Semidiscrete biomass dynamic modeling: an improved approach for assessing fish stock responses to pulsed harvest events
Authors: Colvin Michael E. , Pierce Clay L. , Stewart Timothy W. 
Published: October 2012

Continuous harvest over an annual period is a common assumption of continuous biomass dynamics models (CBDMs); however, fish are frequently harvested in a discrete manner. We developed semidiscrete biomass dynamics models (SDBDMs) that allow discrete harvest events and evaluated differences between CBDMs and SDBDMs using an equilibrium yield analysis with varying levels of fishing mortality (F). Equilibrium fishery yields for CBDMs and SDBDMS were similar at low fishing mortalities and diverged as F approached and exceeded maximum sustained yield (FMSY). Discrete harvest resulted in lower equilibrium yields at high levels of F relative to continuous harvest. The effect of applying harvest continuously when it was in fact discrete was evaluated by fitting CBDMs and SDBDMs to time series data generated from a hypothetical fish stock undergoing discrete harvest and evaluating parameter estimates bias. Violating the assumption of continuous harvest resulted in biased parameter estimates for CBDM while SDBDM parameter estimates were unbiased. Biased parameter estimates resulted in biased biological reference points derived from CBDMs. Semidiscrete BDMs outperformed continuous BDMs and should be used when harvest is discrete, when the time and magnitude of harvest are known, and when F is greater than FMSY.
Leaf quality influences invertebrate colonization and drift in a temperate rainforest stream
Authors: García Liliana , Richardson John S. , Pardo Isabel 
Published: October 2012

Changes in riparian forest composition and diversity, such as plantations of exotic species, may alter resource quality, detritivore assemblages, and litter breakdown rates in streams. We hypothesized that different litter resources may influence colonization and drift of invertebrates inhabiting small, temperate rainforest streams in southwestern British Columbia, Canada. Leaves of different quality and origin were incubated in stream-side channels to test this hypothesis. The sequence of leaf decomposition rates was as follows: alder > alder + cedar > cedar ≥ eucalyptus. Cedar litter decayed faster when mixed with alder than when alone. Invertebrates colonizing leaf bags were predominantly collector–gatherers and shredders, particularly on alder leaves. Drift density varied over the incubation period and seemed to be controlled by leaf quality, since there were more individuals drifting from channels with alder leaves than from channels with cedar or eucalyptus. However, we observed different species-specific invertebrate responses controlled by leaf traits, particularly by numerically dominant chironomid species. Indeed, invertebrate drift from channels incubated with alder bags was mostly due to pupation and emergence of orthoclad midges, whereas this was not observed in the other channels. This differential response in colonization and drift has the potential to modify the transfer rates of organic matter to higher trophic levels and thus ecosystem functioning.
The bioenergetics of density-dependent growth in Arctic char (Salvelinus alpinus)
Authors: Guénard Guillaume , Boisclair Daniel , Ugedal Ola , Forseth Torbjørn , Fleming Ian A. , Jonsson Bror 
Published: October 2012

We explored the mechanisms of density-dependent growth in Arctic char ( Salvelinus alpinus ) by comparing the energetics of growth, consumption, and activity obtained under three replicated density treatments in a large-scale enclosure (90 m2surface area) experiment. The enclosures permitted the entry of zooplankton and allowed char to feed on the bottom and at the surface of the lake. We found a negative (power) relationship between growth and density. Char consumption rate decreased linearly with increasing density. Growth efficiency was affected by fish density in a similar manner as growth rate. Finally, activity increased with fish density and was particularly high at high densities. Our findings illustrate the complexity of the relationships among consumption, activity, growth rates, and fish density and bring further evidence to the possible involvement of behavioural mechanisms in density-dependent processes, notably by modulating activity costs with density.
Analytical and experimental comparison of six algorithms for the vertex cover problem
Authors: Delbot François , Laforest Christian 
Published: October 2012

The vertex cover is a well-known NP-complete minimization problem in graphs that has received a lot of attention these last decades. Many algorithms have been proposed to construct vertex cover in different contexts (offline, online, list algorithms, etc.) leading to solutions of different level of quality. This quality is traditionally measured in terms of approximation ratio, that is, the worst possible ratio between the quality of the solution constructed and the optimal one. For the vertex cover problem the range of such known ratios are between 2 (conjectured as being the smallest constant ratio) and Δ, the maximum degree of the graph. Based on this measure of quality, the hierarchy is almost clear (the smaller the ratio is, the better the algorithm is).
In this article, we show that this measure, although of great importance, is too macroscopic and does not reflect the practical behavior of the methods. We prove this by analyzing (known and recent) algorithms running on a particular class of graphs: the paths. We obtain closed and exact formulas for the mean of the sizes of vertex cover constructed by these different algorithms. Then, we assess their quality experimentally in several well-chosen class of graphs (random, regular, trees, BHOSLIB benchmarks, trap graphs, etc.). The synthesis of all these results lead us to formulate a “practical hierarchy” of the algorithms. We remark that it is, more or less, the opposite to the one only based on approximation ratios, showing that worst-case analysis only gives partial information on the quality of an algorithm.
Bit-vector algorithms for binary constraint satisfaction and subgraph isomorphism
Authors: Ullmann Julian R. 
Published: October 2012

A solution to a binary constraint satisfaction problem is a set of discrete values, one in each of a given set of domains, subject to constraints that allow only prescribed pairs of values in specified pairs of domains. Solutions are sought by backtrack search interleaved with a process that removes from domains those values that are currently inconsistent with provisional choices already made in the course of search. For each value in a given domain, a bit-vector shows which values in another domain are or are not permitted in a solution. Bit-vector representation of constraints allows bit-parallel, therefore fast, operations for editing domains during search. This article revises and updates bit-vector algorithms published in the 1970's, and introduces focus search, which is a new bit-vector algorithm relying more on search and less on domain-editing than previous algorithms. Focus search is competitive within a limited family of constraint satisfaction problems.
Determination of subgraph isomorphism is a specialized binary constraint satisfaction problem for which bit-vector algorithms have been widely used since the 1980s, particularly for matching molecular structures. This article very substantially updates the author's 1976 subgraph isomorphism algorithm, and reports experimental results with random and real-life data.
Enhancing dynamic cloud-based services using network virtualization
Authors: Hao Fang , Lakshman T. V. , Mukherjee Sarit , Song Haoyu 
Published: October 2012

It is envisaged that services and applications will migrate to a cloud-computing paradigm where thin-clients on user-devices access, over the network, applications hosted in data centers by application service providers. Examples are cloud-based gaming applications and cloud-supported virtual desktops. For good performance and efficiency, it is critical that these services are delivered from locations that are the best for the current (dynamically changing) set of users. To achieve this, we expect that services will be hosted on virtual machines in interconnected data centers and that these virtual machines will migrate dynamically to locations best-suited for the current user population. A basic network infrastructure need then is the ability to migrate virtual machines across multiple networks without losing service continuity. In this paper, we develop mechanisms to accomplish this using a network-virtualization architecture that relies on a set of distributed forwarding elements with centralized control (borrowing on several recent proposals in a similar vein). We describe a preliminary prototype system, built using Openflow components, that demonstrates the feasibility of this architecture in enabling seamless migration of virtual machines and in enhancing delivery of
cloud-based services.
Apprehending joule thieves with cinder
Authors: Rumble Stephen M. , Stutsman Ryan , Levis Philip , Mazières David , Zeldovich Nickolai 
Published: October 2012

Energy is the critical limiting resource to mobile computing devices. Correspondingly, an operating system must track, provision, and ration how applications consume energy. The emergence of third-party application stores and marketplaces makes this concern even more pressing. A third-party application must not deny service through excessive, unforeseen energy expenditure, whether accidental or malicious. Previous research has shown promise in tracking energy usage and rationing it to meet device lifetime goals, but such mechanisms and policies are still nascent, especially regarding user interaction.
We argue for a new operating system, called Cinder, which builds on top of the HiStar OS. Cinder's energy awareness is based on hierarchical capacitors and task profiles. We introduce and explore these abstractions, paying particular attention to the ways in which policies could be generated and enforced in a dynamic system.
Characterising temporal distance and reachability in mobile and online social networks
Authors: Tang John , Musolesi Mirco , Mascolo Cecilia , Latora Vito 
Published: October 2012

The analysis of social and technological networks has attracted a lot of attention as social networking applications and mobile sensing devices have given us a wealth of real data. Classic studies looked at analysing static or aggregated networks, i.e., networks that do not change over time or built as the results of aggregation of information over a certain period of time. Given the soaring collections of measurements related to very large, real network traces, researchers are quickly starting to realise that connections are inherently varying over time and exhibit more dimensionality than static analysis can capture.
In this paper we propose new temporal distance metrics to quantify and compare the speed (delay) of information diffusion processes taking into account the evolution of a network from a global view. We show how these metrics are able to capture the temporal characteristics of time-varying graphs, such as delay, duration and time order of contacts (interactions), compared to the metrics used in the past on static graphs. We also characterise network reachability with the concepts of in- and out-components. Then, we generalise them with a global perspective by defining temporal connected components. As a proof of concept we apply these techniques to two classes of time-varying networks, namely connectivity of mobile devices and interactions on an online social network.
Using GPCE principles for hardware systems and accelerators
Authors: Nikhil Rishiyur S. 
Published: October 2012

Moore's Law has precipitated a crisis in the creation of hardware systems (ASICs and FPGAs)-how to design such enormously complex concurrent systems quickly, reliably and affordably? At the same time, portable devices, the energy crisis, and high performance computing present a related challenge-how to move complex and high-performance algorithms from software into hardware (for more speed and/or energy efficiency)?
In this talk I will start with a brief technical introduction to BSV, a language that directly addresses these concerns. It uses ideas from Guarded Atomic Actions (cf. Term Rewriting Systems, TLA+, Unity, and EventB) to address complex concurrency with scalability. It borrows from Haskell (types, type classes, higher-order functions) for robustness and powerful program generation (a.k.a. "static elaboration" to HW designers). And it is fully synthesizable (compilable) into high-quality RTL (Verilog/VHDL). I will then describe some of the remarkable projects that BSV has enabled in industry and academia today.
Classifying Java class transformations for pervasive virtualized access
Authors: McGachey Phil , Hosking Antony L. , Moss J. Eliot B. 
Published: October 2012

The indirection of object accesses is a common theme for target domains as diverse as transparent distribution, persistence, and program instrumentation. Virtualizing accesses to fields and methods (by redirecting calls through accessor and indirection methods) allows interposition of arbitrary code, extending the functionality of an application beyond that intended by the original developer.
We present class modifications performed by our RuggedJ transparent distribution platform for standard Java virtual machines. RuggedJ abstracts over the location of objects by implementing a single object model for local and remote objects. However the implementation of this model is complicated by the presence of native and system code; classes loaded by Java's bootstrap class loader can be rewritten only in a limited manner, and so cannot be modified to conform to RuggedJ's complex object model. We observe that system code comprises the majority of a given Java application: an average of 76% in the applications we study. We consider the constraints imposed upon pervasive class transformation within Java, and present a framework for systematically rewriting arbitrary applications. Our system accommodates all system classes, allowing both user and system classes alike to be referenced using a single object model.
Generating safe template languages
Authors: Heidenreich Florian , Johannes Jendrik , Seifert Mirko , Wende Christian , Böhme Marcel 
Published: October 2012

Template languages are widely used within generative programming, because they provide intuitive means to generate software artefacts expressed in a specific object language. However, most template languages perform template instantiation on the level of string literals, which allows neither syntax checks nor semantics analysis. To make sure that generated artefacts always conform to the object language, we propose to perform static analysis at template design time. In addition, the increasing popularity of domainspecific languages (DSLs) demands an approach that allows to reuse both the concepts of template languages and the corresponding tools.
In this paper we address the issues mentioned above by presenting how existing languages can be automatically extended with generic template concepts (e.g., placeholders, loops, conditions) to obtain safe template languages. These languages provide means for syntax checking and static semantic analysis w.r.t. the object language at template design time. We discuss the prerequisites for this extension, analyse the types of correctness properties that can be assured at template design time, and exemplify the key benefits of this approach on a textual DSL and Java.
Generating execution infrastructures for component-oriented specifications with a model driven toolchain
Authors: Radermacher Ansgar , Cuccuru Arnaud , Gerard Sebastien , Terrier François 
Published: October 2012

The development of embedded Systems becomes more and more complex. Model driven engineering can help to manage this complexity by specifying real-time properties in a declarative way and automating the deployment. The UML profile MARTE is a OMG standard that allows to model real-time properties. However, there is no execution infrastructure that supports MARTE's generic component model (GCM) and the application modeling (HLAM).
The contribution of the paper is twofold: it presents a proposition of a component model with flexible interaction support that allows to tailor code generation to domain and target requirements. Second, it will show how MARTE's GCM concepts can be implemented by means of the proposed component model. The proposed component model has been largely developed in the context of the French national project Flex-eWare with the intention to unify major components model, notably the CORBA component model (CCM) and Fractal. The paper explains the major elements of this model in detail and shows how specific connector and containers can implement MARTE specifications. We present the tool support that is integrated into a UML modeler and based on model-to-model and model to text transformations.
Is hardware innovation over?
Authors: Arvind Professor 
Published: October 2012

My colleagues, promotion committees, research funding agencies and business people often wonder if there is need for any architecture research. There seems to be no room to dislodge Intel IA-32. Even the number of new Application-Specific Integrated Circuits (ASICs) seems to be declining each year, because of the ever-increasing development cost.
This viewpoint ignores another reality which is that the future will be dominated by mobile devices such as smart phones and the infrastructure needed to support consumer services on these devices. This is already restructuring the IT industry. To the first-order, in the mobile world functionality is determined by what can be supported within a 3W power budget. The only way to reduce power by one to two orders of magnitude is via functionally specialized hardware blocks. A fundamental shift is needed in the current design flow of systems-on-a-chip (SoCs) to produce them in a less-risky and cost-effective manner.
In this talk we will present, via examples, a method of designing systems that facilitates the synthesis of complex SoCs from reusable "IP" modules. The technical challenge is to provide a method for connecting modules in a parallel setting so that the functionality and the performance of the composite are predictable.