Reliability and validity of risk analysis

In this paper we investigate to what extent risk analysis meets the scientific quality requirements of reliability and validity. We distinguish between two types of approaches within risk analysis, relative frequency-based approaches and Bayesian approaches. The former category includes both traditional statistical inference methods and the so-called probability of frequency approach. Depending on the risk analysis approach, the aim of the analysis is different, the results are presented in different ways and consequently the meaning of the concepts reliability and validity are not the same.     

Formal verification of a Cooperative Automatic Repeat reQuest MAC protocol

Cooperative communications, in which a relay node helps the source node to deliver its packets to the destination node, are able to obtain significant benefits in terms of transmission reliability, coverage extension and energy efficiency. A Cooperative Automatic Repeat reQuest (C-ARQ) MAC protocol has been recently proposed to exploit cooperative diversity at the MAC layer. In this paper, we validate the integrity and the validity of the C-ARQ protocol using formal methods. The protocol logic is modeled in SDL and implemented in PROMELA. The functionality of the C-ARQ protocol is verified through simulations and verifications using SPIN.     

Modeling the electrical activity of the heart: A Bidomain Model of the ventricles embedded in a torso

In this paper a model for the electrical activity of the heart will be presented and an approach to solve the resulting numerical problem will be suggested. The Bidomain Model is used to compute the spatial distribution of the electrical potential. The partial differential equations are discretized with the finite element method and the multigrid method is used to solve the corresponding linear equations. Adaptivity is applied to resolve the steep gradients in the solution. Received: 24 January 2000 / Accepted: 29 June 2002 / Published online: 10 April 2003 Communicated by G. Wittum     

Cabozantinib Is Effective in Melanoma Brain Metastasis Cell Lines and Affects Key Signaling Pathways

Melanomas have a high potential to metastasize to the brain. Recent advances in targeted therapies and immunotherapies have changed the therapeutical landscape of extracranial melanomas. However, few patients with melanoma brain metastasis (MBM) respond effectively to these treatments and new therapeutic strategies are needed. Cabozantinib is a receptor tyrosine kinase (RTK) inhibitor, already approved for the treatment of non-skin-related cancers. The drug targets several of the proteins that are known to be dysregulated in melanomas. The anti-tumor activity of cabozantinib was investigated using three human MBM cell lines. Cabozantinib treatment decreased the viability of all cell lines both when grown in monolayer cultures and as tumor spheroids. The in vitro cell migration was also inhibited and apoptosis was induced by cabozantinib. The phosphorylated RTKs p-PDGF-Rα, p-IGF-1R, p-MERTK and p-DDR1 were found to be downregulated in the p-RTK array of the MBM cells after cabozantinib treatment. Western blot validated these results and showed that cabozantinib treatment inhibited p-Akt and p-MEK 1/2. Further investigations are warranted to elucidate the therapeutic potential of cabozantinib for patients with MBM.     

Bayesian approaches for detecting significant deterioration

Risk indicators can provide useful input to risk management processes and are given increased attention in the Norwegian petroleum industry. Examples include indicators expressing the proportion of test failures of safety and barrier systems. Such indicators give valuable information about the performance of the systems and provide a basis for trend evaluations. Early warning of a possible deterioration is essential due to the importance of the systems in focus, but what should be the basis for the warning criterion? This paper presents and discusses several Bayesian approaches for the establishment of a warning criterion to disclose significant deterioration. The Norwegian petroleum industry is the starting point for this paper, but the study is relevant for other application areas as well.     

Quantitative structure-activity relationship modelling of ACE-inhibitory peptides derived from milk proteins

The potential of Lactobacillus plantarum, Pediococcus acidilactici, Pediococcus pentocaceus, Lactobacillus cellobiosus, different mixtures of these lactic acid bacteria and backslop starter cultures to acidify and form flavour compounds in uji was investigated. The bacteria chosen are the most prevalent species in fermented uji. Flavour compounds were analysed using GC-MS and GC-FID with HP5 non-polar column and DB-Wax polar columns respectively. Use of pure single or mixed cultures did not improve the flavour profile of fermented uji. On the basis of peak areas of unfermented and fermented uji aromagrams, pentanal, hexanal and hexadecanoic, 9,12-octadecadienoic, oleic and octadecanoic acids were found to be native to the flours, while 3-methyl-1-butanol, octanoate, nonanoate, hexadecanoate, linoleate, oleate and hexanoic, heptanoic, octanoic and nonanoic acids were synthesised during submerged culture fermentation. Ethanol, 1-pentanol, 1-hexanol, lactic acid and ethylacetate were synthesised prior to fermentation and synthesis of these compounds continued during fermentation.     

Screening for peptides from fish and cheese inhibitory to prolyl endopeptidase

Peptides from hydrolysates of fish proteins and from cheeses were analysed for inhibition of prolyl endopeptidase (PE) isolated from porcine muscle. Muscles of cod, salmon, and trout were homogenised and incubated at pH 4.0 with pepsin and then at pH 7.5 with trypsin to obtain fish protein hydrolysates. Homogenates were incubated without exogenous enzymes at pH 4.0 and 7.5 to obtain fish protein autolysates. Water-soluble extracts from "rakfisk" (a Norwegian fermented/autolysed trout muscle dish) and water-soluble extracts from Cheddar, Norvegia, Jarlsberg, and Blue cheese were also prepared. Peptides in the supernatants obtained after heat-treatment of fish hydrolysates, autolysates and water-soluble extracts of rakfisk and cheeses at 95 degrees C for 15 min were analysed for inhibition of PE. Inhibition was also measured in peptide fractions separated by reversed-phase high-performance chromatography and by gel permeation chromatography. The peptide fractions from fish hydrolysates, fish autolysates, and water-soluble extracts of cheeses inhibited PE in hydrolysing Z-Gly-Pro-amidomethylcoumarin. Inhibition by peptides from rakfisk was negligible. Pepsin + trypsin hydrolysates from the three fish species contained PE inhibitory peptides with a broad range of apparent hydrophobicity and apparent molecular mass. Autolysates from muscles of the 3 fish species contained narrow peptide peaks of different molecular mass and different apparent hydrophobicity with strong PE inhibitory activity. The content of hydrophilic inhibitory peptides was lower in cheeses than in pepsin + trypsin hydrolysates of fish muscle.     

Slower acquisition of positively reinforced behavior following medial, but not dorsolateral, septal lesions in rats.

Examined the effects of medial septal lesions (MSLs) and dorsolateral septal lesions (DSLs) on acquisition of leverpressing for water established with a modified autoshaping task. 22 male Sprague-Dawley rats were randomly assigned to receive either MSLs, DSLs, or control operations. Results show that, following MSLs, leverpressing responses had long latencies and were fewer than following either DSLs or control operations. However, during later sessions, MSL Ss started to press. It is suggested that the long response latencies and low response rates shown initially by MSL Ss may have been due to delayed classical conditioning. Following MSLs, the acetylcholinesterase activities of the different subdivisions of the hippocampus correlated positively with the number of leverpress responses emitted during Session 1. DSL Ss acquired the task just as fast as the control group and showed higher response rates than the other 2 groups during the final sessions. These findings are ascribed to generally increased locomotor activity. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)