PADUA: a protocol for argumentation dialogue using association rules

We describe PADUA, a protocol designed to support two agents debating a classification by offering arguments based on association rules mined from individual datasets. We motivate the style of argumentation supported by PADUA, and describe the protocol. We discuss the strategies and tactics that can be employed by agents participating in a PADUA dialogue. PADUA is applied to a typical problem in the classification of routine claims for a hypothetical welfare benefit. We particularly address the problems that arise from the extensive number of misclassified examples typically found in such domains, where the high error rate is a widely recognised problem. We give examples of the use of PADUA in this domain, and explore in particular the effect of intermediate predicates. We have also done a large scale evaluation designed to test the effectiveness of using PADUA to detect misclassified examples, and to provide a comparison with other classification systems.     

PCI Express普及化超乎想象

PCI Express(PCIe)是目前最新的高速串行连接技术之一,短期内将无所不在.由于它继承了全球相当普遍的PCI数据总线,因此这项技术具有快速带动PC及外围配备市场的威力和重大意义,因而受到相当大的重视.因各式各样的需求所致,PCIe足迹已遍布各种应用系统和市场中,未来还会出现在哪些应用上呢?本文将与您共同探讨一二.     

智能手机如何实现数据同步化

手机的使用模式相当简单:用户端口只要离PC数尺的距离,蓝牙手机就能自动进行电子邮件、相片、工作清单、联络人等数据的同步化.但有时用户对蓝牙的同步化与数据传输功能仍存在一些困惑,如PC虽然有蓝牙功能,但却经常无法连上手机如第一次就想让蓝牙功能顺利执行仍需要一些技巧,并不能立马使用等.本文详细为您讲述如何使智能手机实现数据同步化.     

Echium oil is better than rapeseed oil in improving the response of barramundi to a disease challenge

Pathogen infection stimulates the fatty acid (FA) metabolism and the production of pro-inflammatory derivatives of FA. Barramundi, Lates calcarifer, was fed on a diet rich in preformed long-chain (?C₂₀) polyunsaturated fatty acids (LC-PUFA) from fish oil (FO), to compare with diets containing high levels of C₁₈ precursors for LC-PUFA – stearidonic (SDA) and γ-linolenic acid (GLA) – from Echium plantagineum (EO), or rapeseed oil (RO) rich in α-linolenic acid (ALA), but a poor source of LC-PUFA and their precursors. After 6 weeks, when growth rates were similar amongst the dietary treatments, a sub-lethal dose of Streptococcus iniae was administered to half of the fish, while the other half were maintained unchallenged and were pair-fed with the infected fish. Under a disease challenge situation, the tissue FA depots depleted at 3 days post-infection (DPI) and were then restored to their previous concentrations at 7 DPI. During the infection period, EO fish had a higher content of n3 and n6 PUFA in their tissues, higher n3:n6 PUFA ratio and reduced levels of the eicosanoids, TXB₂ and 6-keto-PGF_1α, in their plasma compared with RO fish. Fish fed on FO and EO had a longer lasting and enduring response in their FA and eicosanoid concentrations, following a week of bacterial infection, compared with those fed on RO. EO, containing SDA and GLA and with a comparatively higher n3:n6 PUFA ratio, proved more effective than RO in compensating for immunity stress.     

Isolation and characterization of the microbial population of different South African kefir grains

Kefir, a slightly acidic fermented milk, is produced by adding lactic acid bacteria and yeasts, in the form of grains, to milk. The bacteria and yeasts present in the kefir grains are known to vary widely. Selective growth media and morphological and biochemical characteristics were used for the isolation and identification of the microbes present in the grains from eight different sources in South Africa. The kefir grains were activated in milk for only 24 h to prevent any changes in the microbial population of the grains. The microbial numbers varied between 6.4 × 10⁴ and 8.5 × 10 ⁸  cfu/g on the media selective for the bacterial species and between 1.5 × 10 ⁵ and 3.7 × 10 ⁸   cfu/g on the media selective for the yeast species. The bacterial genera that were identified included Lactobacillus , Leuconostoc and Lactococcus and the yeast genera included Zygosaccharomyces , Candida and Saccharomyces . The distribution frequencies of the microbes in the different grains were determined and most of the grains were dominated by two microbial species. No pediococci, acetic acid bacteria or propionibacteria were detected.     

Novel probiotic-fermented milk with angiotensin I-converting enzyme inhibitory peptides produced by Bifidobacterium bifidum MF 20/5

In previous research, we have demonstrated that Bifidobacterium bifidum MF 20/5 fermented milk possessed stronger angiotensin converting enzyme (ACE) inhibitory activity than other lactic acid bacteria, including Lactobacillus helveticus DSM 13137, which produces the hypotensive casokinins Ile-Pro-Pro (IPP) and Val-Pro-Pro (VPP). The aim of this study is to investigate the ACE-inhibitory peptides released in B. bifidum MF 20/5 fermented milk. The novel ACE-inhibitory peptide LVYPFP (IC₅₀ = 132 μM) is reported here for the first time. Additionally, other bioactive peptides such as the ACE-inhibitor LPLP (IC₅₀ = 703 μM), and the antioxidant VLPVPQK were identified. Moreover, the peptide and amino acid profiles, the ACE-inhibitory activity (ACEi), pH, and degree of hydrolysis of the fermented milk were determined and compared with those obtained in milk fermented by L. helveticus DSM 13137. The sequences of the major bioactive peptides present in fermented milk of B. bifidum and L. helveticus were identified and quantified. B. bifidum released a larger amount of peptides than L. helveticus but no IPP or VPP were detected in B. bifidum fermented milk. Also the lactotripeptide concentrations and ACEi were higher in L. helveticus fermented milk when the pH was maintained at 4.6. This may represent a technical advantage for B. bifidum that reduces the pH at a slow enough rate to facilitate the peptide generation without the need for pH control. Thus these findings show the potential for the use of this probiotic strain to produce fermented milk with a wider range of health benefits including reduction of blood pressure.     

Biomagnification of perfluoroalkyl compounds in the bottlenose dolphin (Tursiops truncatus) food web

The environmental distribution and the biomagnification of a suite of perfluoroalkyl compounds (PFCs), including perfluorooctane sulfonate (PFOS) and C8 to C14 perfluorinated carboxylates (PFCAs), was investigated in the food web of the bottlenose dolphin (Tursiops truncatus). Surficial seawater and sediment samples, as well as zooplankton, fish, and bottlenose dolphin tissue samples, were collected at two U.S. locations: Sarasota Bay, FL and Charleston Harbor, SC. Wastewater treatment plant (WWTP) effluents were also collected from the Charleston area (n = 4). A solid-phase extraction was used for seawater and effluent samples and an ion-pairing method was used for sediment and biotic samples. PFCs were detected in seawater (range <1-12 ng/L), sediment (range <0.01-0.4 ng/g wet weight (ww)), and zooplankton (range 0.06-0.3 ng/g ww). The highest PFC concentrations were detected in WWTP effluents, whole fish, and dolphin plasma and tissue samples in which PFOS, C8 and C10-PFCAs predominated in most matrices. Contamination profiles varied with location suggesting different sources of PFC emissions. Biomagnification factors (BMFs) ranged from <1 to 156 at Sarasota Bay and <1 to 30 at Charleston. Trophic magnification factors (TMFs) for PFOS and C8-C11 PFCAs indicated biomagnification in this marine food web. The results indicate that using plasma and liver PFC concentrations as surrogate to whole body burden in a top marine predator overestimates the BMFs and TMFs.     

Life-cycle assessment of diesel, natural gas and hydrogen fuel cell bus transportation systems

The Sustainable Transport Energy Programme (STEP) is an initiative of the Government of Western Australia, to explore hydrogen fuel cell technology as an alternative to the existing diesel and natural gas public transit infrastructure in Perth. This project includes three buses manufactured by DaimlerChrysler with Ballard fuel cell power sources operating in regular service alongside the existing natural gas and diesel bus fleets. The life-cycle assessment (LCA) of the fuel cell bus trial in Perth determines the overall environmental footprint and energy demand by studying all phases of the complete transportation system, including the hydrogen infrastructure, bus manufacturing, operation, and end-of-life disposal. The LCAs of the existing diesel and natural gas transportation systems are developed in parallel. The findings show that the trial is competitive with the diesel and natural gas bus systems in terms of global warming potential and eutrophication. Emissions that contribute to acidification and photochemical ozone are greater for the fuel cell buses. Scenario analysis quantifies the improvements that can be expected in future generations of fuel cell vehicles and shows that a reduction of greater than 50% is achievable in the greenhouse gas, photochemical ozone creation and primary energy demand impact categories.     

Fuel cycle analysis of GFR using advanced fuels

The potential benefits of a synergistic light-water reactor (LWR) and gas-cooled fast reactor (GFR) fuel cycle were evaluated for its impact on the front-end and back-end of the fuel cycle. Comparisons were made with conventional once-through cycle (OTC) and MOX fuel cycle. Variations in the synergistic LWR/GFR fuel cycles were based on the degree of recycle in the LWR including both plutonium and reprocessed uranium with concomitant impact on used LWR fuel inventory. This provided a wide range in composition of GFR feed from low to high plutonium content with impact on transmutation/incineration within the GFR fuel cycle. Self-recycle of all actinides was modeled for the GFR with analyses demonstrating that the GFR can be sustained on and consequently accept a wide range of feed materials. Analyses were done using Monteburns along with MCNP and Origen2.2 to model a 60-year period corresponding to the anticipated lifetime of supposed contemporary LWRs and GFRs. All cycles were evaluated based on actinide total mass and isotopic inventory, radiotoxicity, heatload, and resource requirements including natural uranium and SWU. For comparison, all fuel cycles were normalized based on 1 TWHe output. Improvements in fuel cycle performance are dictated by the production and incineration of minor actinides in the GFR and their continued recycle may not be feasible due to the buildup of troublesome isotopes such as ²⁴⁴Cm and ²⁵²Cf. But where uranium and plutonium continue to be recycled beyond the 60-year period, the LWR/GFR cycles demonstrated order of magnitude reductions in used fuel inventories, heatload, and radiotoxicity on a per TWHe basis over LWR only cycles. The full details of the advanced fuel cycle methodology and results are presented.