A Web server is a wonderful business communication channel — it relays information cheaply, conveniently and, in theory, to almost everyone. Traditionally, in my experience at least, the Web is not an area auditors have taken particularly seriously: until recently, it has not been used to transact business, but simply to publicize the organization. Most companies run their Web applications on a firewall interface or interfaces outside the internal network, so the audit, more concerned with the core business applications, could rely on the firewall to protect against hackers, and treat the Web server as, at worst, a bastion host. 相似文献
The pathogenesis of progressive renal allograft injury, which is termed chronic allograft nephropathy (CAN), remains obscure and is currently defined by histology. Prospective protocol-biopsy trials have demonstrated that clinical and standard laboratory tests are insufficiently sensitive indicators of the development and progression of CAN. The study aim was to determine if CAN could be characterized by urinary proteomic data and identify the proteins associated with disease. The urinary proteome of 75 renal transplant recipients and 20 healthy volunteers was analyzed using surface enhanced laser desorption and ionization MS. Patients could be classified into subgroups with normal histology and Banff CAN grades 2-3 with a sensitivity of 86% and a specificity of 92% by applying the classification algorithm Adaboost to urinary proteomic data. Several urinary proteins associated with advanced CAN were identified including α1-microglobulin, β2-microglobulin, prealbumin, and endorepellin, the antiangiogenic C-terminal fragment of perlecan. Increased urinary endorepellin was confirmed by ELISA and increased tissue expression of the endorepellin/perlecan ratio by immunofluoresence analysis of renal biopsies. In conclusion, analysis of urinary proteomic data has further characterized the more severe CAN grades and identified urinary endorepellin, as a potential biomarker of advanced CAN. 相似文献
There were 35 oesophageal intubations in the first 2000 incidents reported to the Australian Incident Monitoring Study (AIMS). These reports confirm existing impressions that misplacement of the endotracheal tube can occur in trained as well as untrained hands, and that auscultation is an unreliable test. On the other hand, the value of capnography is emphasised, with no false positives in the 16 cases in which the instrument was used. There was one false negative. Over the 4 years of the AIMS study, reports have declined in frequency. It is possible that the early detection of oesophageal intubation by capnography has altered its status to the extent that anaesthetists no longer regard it as a "critical" incident. It is highly recommended that the presence of the expected concentration of carbon dioxide in expired air be confirmed by capnography immediately after any endotracheal intubation. 相似文献
For successful parasitization, the female Campoletis sonorensis endoparasitic wasp injects a polydnavirus into its host, Heliothis virescens, during oviposition. Viral gene expression induces immunosuppression and alters development of the host. We report here that three abundantly expressed genes, VHv1.1, WHv1.0, and WHv1.6, describes a polydnavirus "cysteine-rich" gene family which may be important in inducing these host manifestations. These genes have a similar primary gene structure and their proteins contain cysteine motifs characteristic of snail ion-channel ligands, the omega-conotoxins. Like the omega-conotoxins, the intercysteine amino acid residues are hypervariable with only three identical amino acids in all motifs. The conservation of this domain in the three viral genes may reflect an important functional role for these viral proteins in the parasitization of H. virescens. The three genes also contain introns similar in sequence at comparable positions in their 5' untranslated leaders and coding sequences. VHv1.1 contains two cysteine motifs, and each motif is interrupted by an intron at the same position as in the cysteine motifs of WHv1.0 and WHv1.6. Intron 2 sequences of WHv1.0 and WHv1.6 are 92% identical, while the immediately flanking exon sequences encoding the cysteine motifs are only 76% identical. This provides an example of nuclear pre-mRNA introns which are more conserved than flanking exons among members of a gene family. 相似文献
Semi-naive Bayesian techniques seek to improve the accuracy of naive Bayes (NB) by relaxing the attribute independence assumption.
We present a new type of semi-naive Bayesian operation, Subsumption Resolution (SR), which efficiently identifies occurrences
of the specialization-generalization relationship and eliminates generalizations at classification time. We extend SR to Near-Subsumption
Resolution (NSR) to delete near–generalizations in addition to generalizations. We develop two versions of SR: one that performs
SR during training, called eager SR (ESR), and another that performs SR during testing, called lazy SR (LSR). We investigate
the effect of ESR, LSR, NSR and conventional attribute elimination (BSE) on NB and Averaged One-Dependence Estimators (AODE),
a powerful alternative to NB. BSE imposes very high training time overheads on NB and AODE accompanied by varying decreases
in classification time overheads. ESR, LSR and NSR impose high training time and test time overheads on NB. However, LSR imposes
no extra training time overheads and only modest test time overheads on AODE, while ESR and NSR impose modest training and
test time overheads on AODE. Our extensive experimental comparison on sixty UCI data sets shows that applying BSE, LSR or
NSR to NB significantly improves both zero-one loss and RMSE, while applying BSE, ESR or NSR to AODE significantly improves
zero-one loss and RMSE and applying LSR to AODE significantly improves zero-one loss. The Friedman test and Nemenyi test show
that AODE with ESR or NSR have a significant zero-one loss and RMSE advantage over Logistic Regression and a zero-one loss
advantage over Weka’s LibSVM implementation with a grid parameter search on categorical data. AODE with LSR has a zero-one
loss advantage over Logistic Regression and comparable zero-one loss with LibSVM. Finally, we examine the circumstances under
which the elimination of near-generalizations proves beneficial. 相似文献
The Sieverts technique is a popular method of measuring the uptake of gas on a sample and is an important tool for the characterisation of hydrogen uptake by potential hydrogen storage materials. An analysis of the consequences of errors in the calibration of volumes in this technique has been made using hydrogen absorption on an AB2 alloy as an example. Trends in the error in the uptake as a function of errors in the volumes have been explained in terms of the equations for uptake. Significant advantages are found for calibration techniques for which the ratio of volumes is an intrinsic measurement. 相似文献
Averaged n-Dependence Estimators (AnDE) is an approach to probabilistic classification learning that learns by extrapolation from marginal to full-multivariate
probability distributions. It utilizes a single parameter that transforms the approach between a low-variance high-bias learner
(Naive Bayes) and a high-variance low-bias learner with Bayes optimal asymptotic error. It extends the underlying strategy
of Averaged One-Dependence Estimators (AODE), which relaxes the Naive Bayes independence assumption while retaining many of
Naive Bayes’ desirable computational and theoretical properties. AnDE further relaxes the independence assumption by generalizing AODE to higher-levels of dependence. Extensive experimental
evaluation shows that the bias-variance trade-off for Averaged 2-Dependence Estimators results in strong predictive accuracy
over a wide range of data sets. It has training time linear with respect to the number of examples, learns in a single pass
through the training data, supports incremental learning, handles directly missing values, and is robust in the face of noise.
Beyond the practical utility of its lower-dimensional variants, AnDE is of interest in that it demonstrates that it is possible to create low-bias high-variance generative learners and suggests
strategies for developing even more powerful classifiers. 相似文献
To assess the tumour dimensions in uveal melanoma patients using 7-T ocular MRI and compare these values with conventional ultrasound imaging to provide improved information for treatment options.
Materials and methods
Ten uveal melanoma patients were examined on a 7-T MRI system using a custom-built eye coil and dedicated 3D scan sequences to minimise eye-motion-induced image artefacts. The maximum tumour prominence was estimated from the three-dimensional images and compared with the standard clinical evaluation from 2D ultrasound images.
Results
The MRI protocols resulted in high-resolution motion-free images of the eye in which the tumour and surrounding tissues could clearly be discriminated. For eight of the ten patients the MR images showed a slightly different value of tumour prominence (average 1.0 mm difference) compared to the ultrasound measurements, which can be attributed to the oblique cuts through the tumour made by the ultrasound. For two of these patients the more accurate results from the MR images changed the treatment plan, with the smaller tumour dimensions making them eligible for eye-preserving therapy.
Conclusion
High-field ocular MRI can yield a more accurate measurement of the tumour dimensions than conventional ultrasound, which can result in significant changes in the prescribed treatment.
ARMA models provide a parsimonious and flexible mechanism for modeling the evolution of a time series. Some useful measures of these models (e.g., the autocorrelation function or the spectral density function) are tedious to compute by hand. This paper uses a computer algebra system, not simulation, to calculate measures of interest associated with ARMA models. 相似文献