188 research outputs found
Darwinian Data Structure Selection
Data structure selection and tuning is laborious but can vastly improve an
application's performance and memory footprint. Some data structures share a
common interface and enjoy multiple implementations. We call them Darwinian
Data Structures (DDS), since we can subject their implementations to survival
of the fittest. We introduce ARTEMIS a multi-objective, cloud-based
search-based optimisation framework that automatically finds optimal, tuned DDS
modulo a test suite, then changes an application to use that DDS. ARTEMIS
achieves substantial performance improvements for \emph{every} project in
Java projects from DaCapo benchmark, popular projects and uniformly
sampled projects from GitHub. For execution time, CPU usage, and memory
consumption, ARTEMIS finds at least one solution that improves \emph{all}
measures for () of the projects. The median improvement across
the best solutions is , , for runtime, memory and CPU
usage.
These aggregate results understate ARTEMIS's potential impact. Some of the
benchmarks it improves are libraries or utility functions. Two examples are
gson, a ubiquitous Java serialization framework, and xalan, Apache's XML
transformation tool. ARTEMIS improves gson by \%, and for
memory, runtime, and CPU; ARTEMIS improves xalan's memory consumption by
\%. \emph{Every} client of these projects will benefit from these
performance improvements.Comment: 11 page
Absolute lymphocyte and neutrophil counts in neonatal ischemic brain injury
Objectives: This study aimed to identify differences in absolute neutrophils, lymphocytes, and neutrophil-to-lymphocyte ratio between neonates with two forms of ischemic brain injury, hypoxic-ischemic encephalopathy, and acute ischemic stroke, compared to controls. We also aimed to determine whether this neutrophil/lymphocyte response pattern is associated with disease severity or is a consequence of the effects of total-body cooling, an approved treatment for moderate-to-severe hypoxic-ischemic encephalopathy. Methods: A retrospective chart review of 101 neonates with hypoxic-ischemic encephalopathy+total-body cooling (n=26), hypoxic-ischemic encephalopathy (n=12), acute ischemic stroke (n=15), and transient tachypnea of the newborn (n=48) was conducted; transient tachypnea of the newborn neonates were used as the control group. Absolute neutrophil count and absolute lymphocyte count at three time-intervals (0–12, 12–36, and 36–60 h after birth) were collected, and neutrophilto-lymphocyte ratio was calculated. Results: Hypoxic-ischemic encephalopathy+total-body cooling neonates demonstrated significant time-interval-dependent changes in absolute lymphocyte count and neutrophil-to-lymphocyte ratio levels compared to transient tachypnea of the newborn and acute ischemic stroke patients. Pooled analysis of absolute lymphocyte count for neonates with acute ischemic stroke and hypoxic-ischemic encephalopathy (not hypoxic-ischemic encephalopathy+total-body cooling) revealed that absolute lymphocyte count changes occurring at 0–12h are likely due to disease progression, rather than total-body cooling treatment. Conclusion: These data suggest that the neutrophil/lymphocyte response is modulated following neonatal ischemic brain injury, representing a possible target for therapeutic intervention. However, initial severity of hypoxic-ischemic encephalopathy among these patients could also account for the observed changes in the immune response to injury. Thus, additional work to clarify the contributions of cooling therapy and disease severity to neutrophil/lymphocyte response following hypoxicischemic encephalopathy in neonates is warranted
Evolution of mal ABC transporter operons in the Thermococcales and Thermotogales
<p>Abstract</p> <p>Background</p> <p>The <it>mal </it>genes that encode maltose transporters have undergone extensive lateral transfer among ancestors of the archaea <it>Thermococcus litoralis </it>and <it>Pyrococcus furiosus</it>. Bacterial hyperthermophiles of the order <it>Thermotogales </it>live among these archaea and so may have shared in these transfers. The genome sequence of <it>Thermotoga maritima </it>bears evidence of extensive acquisition of archaeal genes, so its ancestors clearly had the capacity to do so. We examined deep phylogenetic relationships among the <it>mal </it>genes of these hyperthermophiles and their close relatives to look for evidence of shared ancestry.</p> <p>Results</p> <p>We demonstrate that the two maltose ATP binding cassette (ABC) transporter operons now found in <it>Tc. litoralis </it>and <it>P. furiosus </it>(termed <it>mal </it>and <it>mdx </it>genes, respectively) are not closely related to one another. The <it>Tc. litoralis </it>and <it>P. furiosus mal </it>genes are most closely related to bacterial <it>mal </it>genes while their respective <it>mdx </it>genes are archaeal. The genes of the two <it>mal </it>operons in <it>Tt. maritima </it>are not related to genes in either of these archaeal operons. They are highly similar to one another and belong to a phylogenetic lineage that includes <it>mal </it>genes from the enteric bacteria. A unique domain of the enteric MalF membrane spanning proteins found also in these <it>Thermotogales </it>MalF homologs supports their relatively close relationship with these enteric proteins. Analyses of genome sequence data from other <it>Thermotogales </it>species, <it>Fervidobacterium nodosum</it>, <it>Thermosipho melanesiensis</it>, <it>Thermotoga petrophila</it>, <it>Thermotoga lettingae</it>, and <it>Thermotoga neapolitana</it>, revealed a third apparent <it>mal </it>operon, absent from the published genome sequence of <it>Tt. maritima </it>strain MSB8. This third operon, <it>mal3</it>, is more closely related to the <it>Thermococcales</it>' bacteria-derived <it>mal </it>genes than are <it>mal1 </it>and <it>mal2</it>. <it>F. nodosum</it>, <it>Ts. melanesiensis</it>, and <it>Tt. lettingae </it>have only one of the <it>mal1-mal2 </it>paralogs. The <it>mal2 </it>operon from an unknown species of <it>Thermotoga </it>appears to have been horizontally acquired by a <it>Thermotoga </it>species that had only <it>mal1</it>.</p> <p>Conclusion</p> <p>These data demonstrate that the <it>Tc. litoralis </it>and <it>P. furiosus mdx </it>maltodextrin transporter operons arose in the <it>Archaea </it>while their <it>mal </it>maltose transporter operons arose in a bacterial lineage, but not the same lineage as the two maltose transporter operons found in the published <it>Tt. maritima </it>genome sequence. These <it>Tt. maritima </it>maltose transporters are phylogenetically and structurally similar to those found in enteric bacteria and the <it>mal2 </it>operon was horizontally transferred within the <it>Thermotoga </it>lineage. Other <it>Thermotogales </it>species have a third <it>mal </it>operon that is more closely related to the bacterial <it>Thermococcales mal </it>operons, but the data do not support a recent horizontal sharing of that operon between these groups.</p
OPTIMIZATION OF TOOL GEOMETRY AND CUTTING PARAMETERS FOR TURNING OPERATIONS BASED ON RESPONSE SURFACE METHODOLOGY
ABSTRACT This investigation focuses on the influence of tool geometry (nose radius) and cutting parameters (cutting speed, feed and depth of cut) on the surface finish obtained in turning of mild Steel. In order to find the effect of tool geometry and cutting parameters on the surface roughness during turning, response surface methodology (RSM) with (3 4 ) full factorial design was used and a prediction model was developed related to average surface roughness (Ra) using experimental data. The results indicated that the tool nose radius was the dominant factor on surface roughness. In addition, a good agreement between the predicted and measured surface roughness was observed. Therefore, the developed model can be effectively used to predict the surface roughness on the machining of mild steel with 95 % confidence interval within ranges of parameter studied
Effects of time window size and placement on the structure of aggregated networks
Complex networks are often constructed by aggregating empirical data over
time, such that a link represents the existence of interactions between the
endpoint nodes and the link weight represents the intensity of such
interactions within the aggregation time window. The resulting networks are
then often considered static. More often than not, the aggregation time window
is dictated by the availability of data, and the effects of its length on the
resulting networks are rarely considered. Here, we address this question by
studying the structural features of networks emerging from aggregating
empirical data over different time intervals, focussing on networks derived
from time-stamped, anonymized mobile telephone call records. Our results show
that short aggregation intervals yield networks where strong links associated
with dense clusters dominate; the seeds of such clusters or communities become
already visible for intervals of around one week. The degree and weight
distributions are seen to become stationary around a few days and a few weeks,
respectively. An aggregation interval of around 30 days results in the stablest
similar networks when consecutive windows are compared. For longer intervals,
the effects of weak or random links become increasingly stronger, and the
average degree of the network keeps growing even for intervals up to 180 days.
The placement of the time window is also seen to affect the outcome: for short
windows, different behavioural patterns play a role during weekends and
weekdays, and for longer windows it is seen that networks aggregated during
holiday periods are significantly different.Comment: 19 pages, 11 figure
Bringing LTL Model Checking to Biologists
The BioModelAnalyzer (BMA) is a web based tool for the development of discrete models of biological systems. Through a graphical user interface, it allows rapid development of complex models of gene and protein interaction networks and stability analysis without requiring users to be proficient computer programmers. Whilst stability is a useful specification for testing many systems, testing temporal specifications in BMA presently requires the user to perform simulations. Here we describe the LTL module, which includes a graphical and natural language interfaces to testing LTL queries. The graphical interface allows for graphical construction of the queries and presents results visually in keeping with the current style of BMA. The Natural language interface complements the graphical interface by allowing a gentler introduction to formal logic and exposing educational resources
ACQR: Acoustic Quick Response Codes for Content Sharing on Low End Phones with No Internet Connectivity.
ABSTRACT In this paper we introduce Acoustic Quick Response codes to facilitate sharing between Interactive Voice Response (IVR) service users. IVRs are telephone-based, and similar to the world wide web in many aspects, but currently lack support for content sharing. Our approach uses 'audio codes' to let people share their call positions, and allows callers to hold their normal (low-end) handsets together to synchronise. The technique uses remote generation and recognition of audio codes to ensure that sharing is possible on any type of phone without the need for textual literacy or an internet connection. We begin by exploring existing user needs for sharing, then evaluate the technical robustness of our audio-based design. We demonstrate the value of the approach for voice service users over several separate studies-including an eight-month extended field deployment-then conclude with a discussion of future possibilities for such scenarios
Photoactive Ag(I)-based coordination polymer as a potential semiconductor for photocatalytic water splitting and environmental remediation: experimental and theoretical approach
Metal–organic frameworks or metal coordination polymers (CPs) with controlled structure on the micro/nanoscale have attracted intense interest for potential applications in a wide variety of fields, such as energy storage and conversion, chemical and biological sensing, and catalysis. Here, we report a new class of photocatalytic material, Ag(I)-based nano-micro-structured coordination polymer (Ag(I)-CP), which offers performance at a level competitive with known semiconductors in photocatalytic water oxidation and oxidation of organic compounds, such as dye/organic pollutants present in contaminated water. The coordination polymer was synthesized by a wet-chemical route and has been characterized using powder X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopy. The Ag(I)-CP has notable semiconducting characteristics and charge transfer ability due to ligand-centered charge transfer in combination with metal-to-ligand charge transfer (Ag–O cluster to ligand center), as established from experimental absorption, luminescence, and photoelectrochemical measurements alongside density functional theory calculations. Notably, Ag(I)-CP exhibits a highly reactive valance band potential +3.40 V vs NHE, composed of hybridized state of O 2p and C 2p through the organic linker and Ag 4d; this acts as an active center for the generation of reactive oxygen species, i.e., hydroxyl radical and h+ under photocatalytic conditions. Consequently, the photogenerated species facilitate effective oxidations of water and organic contaminants such as tartrazine, rhodamine B, and 2,4-dichlorophenol under UV light irradiation. Furthermore, our results suggest that the Ag(I)-CP could be used as a promising material for the development of heterostructure for a variety of photoassisted redox catalysis reactions
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