4,554 research outputs found
Yes-no Bloom filter: A way of representing sets with fewer false positives
The Bloom filter (BF) is a space efficient randomized data structure
particularly suitable to represent a set supporting approximate membership
queries. BFs have been extensively used in many applications especially in
networking due to their simplicity and flexibility. The performances of BFs
mainly depends on query overhead, space requirements and false positives. The
aim of this paper is to focus on false positives. Inspired by the recent
application of the BF in a novel multicast forwarding fabric for information
centric networks, this paper proposes the yes-no BF, a new way of representing
a set, based on the BF, but with significantly lower false positives and no
false negatives. Although it requires slightly more processing at the stage of
its formation, it offers the same processing requirements for membership
queries as the BF. After introducing the yes-no BF, we show through
simulations, that it has better false positive performance than the BF
Information-Centric Multilayer Networking: Improving Performance Through an ICN/WDM Architecture
Information-centric networking (ICN) facilitates content identification in networks and offers parametric representation of content semantics. This paper proposes an ICN/WDM network architecture that uses these features to offer superior network utilization, in terms of performance and power consumption. The architecture introduces an ICN publish/subscribe communication approach to the wavelength layer, whereby content is aggregated according to its popularity rank into wavelength-size groups that can be published and subscribed to by multiple nodes. Consequently, routing and wavelength assignment (RWA) algorithms benefit from anycast to identify multiple sources of aggregate content and allow optimization of the source selection of light paths. A power-aware algorithm, maximum degree of connectivity, has been developed with the objective of exploiting this flexibility to address the tradeoff between power consumption and network performance. The algorithm is also applicable to IP architectures, albeit with less flexibility. Evaluation results indicate the superiority of the proposed ICN architecture, even when utilizing conventional routing methods, compared with its IP counterpart. The results further highlight the performance improvement achieved by the proposed algorithm, compared with the conventional RWA methods, such as shortest-path first fit
Tributyltin (TBT) and the decline of the Norfolk Broads
This is the final report to the Department for Environment, Food & Rural Affairs (DEFRA) on the contract "Tributyltin (TBT) and the decline of the Norfolk Broads"
On the size and orientation effect in additive manufactured Ti-6Al-4V
In this work, the influence of the specimen size and orientation on the strength and ductility of additive manufactured Ti-6Al-4V is analysed and rationalised in a complete framework. First, the mechanical properties are addressed – as a function of surface-type, orientation, and size. Our results show systematic strengthening and a drastic drop in ductility as the material section is reduced. These changes are rationalised and linked to changes in microstructure, chemistry, and surface quality. Strengthening is due to combined changes in α-lath thickness, oxygen enrichment, and prior-β grain size. The microstructural changes are due to the differences in the ratio between contouring and hatching laser strategies as the sample size decreases. Changes in the chemical composition is due to an increase in the surface-to-volume ratio as the sample size decreases. Lost of ductility is due to poor surface quality – smaller sections show rougher surfaces – and grain orientations. Finally, these findings are used to develop a set of conceptual design maps of strength and ductility as a function of the component type, thickness, and orientation
Delirium is under-reported in discharge summaries and in hospital administrative systems: a systematic review
Background
Accurate recording of delirium in discharge summaries (DS) and hospital administrative systems (HAS) is critical for patient care.
Objective
To systematically review studies reporting the frequency of delirium documentation and coding in DS and HAS, respectively.
Method
We searched Medline, Embase, PsycINFO and Web of Science databases from inception to 23 June 2021. Eligibility criteria included requiring the term delirium in DS or HAS. Screening and full-text reviews were performed independently by two reviewers. Risk of bias (RoB) was assessed using the Effective Public Health Practice Project tool.
Results
The search yielded 7,910 results; 24 studies were included. The studies were heterogeneous in design and size (N=25 to 809,512). Mean age ranged from 57 to 84 years. Four studies reported only overall DS documentation and HAS coding in whole hospital or healthcare databases. Twenty studies used additional delirium ascertainment methods (e.g. chart review) in smaller patient subsets. Studies reported either DS figures only (N=8), HAS figures only (N=11), or both (N=5). Documentation rates in DS ranged from 0.1% to 64%. Coding rates in HAS ranged from 1.5% to 49%. Some studies explored the impact of race, and nurse versus physician practice. No significant differences were reported for race; one study reported that nurses showed higher documentation rates in DS relative to physicians. Most studies (N=22) had medium to high RoB.
Conclusion
Delirium is a common and serious medical emergency, yet studies show considerable under-documentation and under-coding in healthcare systems. This has important implications for patient care and service planning. Healthcare systems need to take action to reach satisfactory delirium documentation and coding rates
Knockout studies reveal an important role of <i>plasmodium</i> lipoic acid protein ligase a1 for asexual blood stage parasite survival
Lipoic acid (LA) is a dithiol-containing cofactor that is essential for the function of a-keto acid dehydrogenase complexes. LA acts as a reversible acyl group acceptor and 'swinging arm' during acyl-coenzyme A formation. The cofactor is post-translationally attached to the acyl-transferase subunits of the multienzyme complexes through the action of octanoyl (lipoyl): <i>N</i>-octanoyl (lipoyl) transferase (LipB) or lipoic acid protein ligases (LplA). Remarkably, apicomplexan parasites possess LA biosynthesis as well as scavenging pathways and the two pathways are distributed between mitochondrion and a vestigial organelle, the apicoplast. The apicoplast-specific LipB is dispensable for parasite growth due to functional redundancy of the parasite's lipoic acid/octanoic acid ligases/transferases. In this study, we show that <i>LplA1</i> plays a pivotal role during the development of the erythrocytic stages of the malaria parasite. Gene disruptions in the human malaria parasite <i>P.falciparum</i> consistently were unsuccessful while in the rodent malaria model parasite <i>P. berghei</i> the <i>LplA1</i> gene locus was targeted by knock-in and knockout constructs. However, the <i>LplA1</i> <sup>(-)</sup> mutant could not be cloned suggesting a critical role of LplA1 for asexual parasite growth <i>in vitro</i> and <i>in vivo</i>. These experimental genetics data suggest that lipoylation during expansion in red blood cells largely occurs through salvage from the host erythrocytes and subsequent ligation of LA to the target proteins of the malaria parasite
Electronic stress tensor analysis of hydrogenated palladium clusters
We study the chemical bonds of small palladium clusters Pd_n (n=2-9)
saturated by hydrogen atoms using electronic stress tensor. Our calculation
includes bond orders which are recently proposed based on the stress tensor. It
is shown that our bond orders can classify the different types of chemical
bonds in those clusters. In particular, we discuss Pd-H bonds associated with
the H atoms with high coordination numbers and the difference of H-H bonds in
the different Pd clusters from viewpoint of the electronic stress tensor. The
notion of "pseudo-spindle structure" is proposed as the region between two
atoms where the largest eigenvalue of the electronic stress tensor is negative
and corresponding eigenvectors forming a pattern which connects them.Comment: 22 pages, 13 figures, published online, Theoretical Chemistry
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