The feasibility of data whitening to improve performance of weather radar

The problem of efficient processing of correlated weather radar echoes off precipitation is considered. An approach based on signal whitening was recently proposed that has the potential to significantly improve power estimation at a fixed pulse repetition rate/scan rate, or to allow higher scan rates at a given level of accuracy. However, the previous work has been mostly theoretical and subject to the following restrictions: 1) the autocorrelation function (ACF) of the process must be known precisely and 2) infinite signal-to-noise ratio is assumed. Here a computational feasibility study of the whitening algorithm when the ACF is estimated and in the presence of noise is discussed. In the course of this investigation numerical instability to the ACF behavior at large lags (tails) was encountered. In particular, the commonly made assumption of the Gaussian power spectrum and, therefore, Gaussian ACF yields numerically ill-conditioned covariance matrices. The origin of this difficulty, rooted in the violation of the requirement of positive Fourier transform of the ACF, is discussed. It is found that small departures from the Gaussian form of the covariance matrix result in greatly reduced ill conditioning of the matrices and robustness with respect to noise. The performance of the whitening technique for various meteorologically reasonable scenarios is then examined. The effects of additive noise are also investigated. The approach, which uses time series to estimate the ACF from which the whitener is constructed, shows up to an order of magnitude improvement in the mean-squared error of the estimated power for a range of parameter values corresponding to typical meteorological situations

The use of electronic communication for patient-professional interaction – nursing staff’s point of view

Patient care in hospital wards is decreasing dramatically; more and more often, it takes place at home and in outpatient clinics. New ways to communicate are thus needed between patients and professionals. The use of electronic devices is one possible solution to facilitate the communication and support modern care.The purpose of the study was to describe nursing staff’s skills and experiences on the use of electronic communication for interaction with patients. The study also looks at factors promoting and hindering the use of electronic communication. The study used a descriptive design including both qualitative and quantitative components. The data were collected among nursing staff (N=567, n=123) working in outpatient clinics in spring 2012 with an electronic questionnaire.Computer and electronic communication skills among nursing staff were at a moderately good level. They had most experience in the use of email and text messages. Electronic devices were used at all stages of the nursing process. Three main categories were formed to describe promoting and hindering factors for the use of electronic communication: user-related factors; technology- and organization-related factors; and nursing- and communication-related factors. According to the participants, electronic devices are necessary and useful tools in interacting with patients. Patients’ personal characteristics and information security problems were perceived as the most significant hindering factors.The use of technology benefited both the nursing staff and patients in communication. The nurses’ experiences on the use of electronic communication were not very extensive as emails and text messages were the most commonly used methods.</p

19F NMR spectroscopy monitors ligand binding to recombinantly fluorine-labelled b'x from human protein disulphide isomerase (hPDI)

We report a protein-observe (19)F NMR-based ligand titration binding study of human PDI b'x with ?-somatostatin that also emphasises the need to optimise recombinant protein fluorination when using 5- or 6-fluoroindole. This study highlights a recombinant preference for 5-fluoroindole over 6-fluoroindole; most likely due to the influence of fluorine atomic packing within the folded protein structure. Fluorination affords a single (19)F resonance probe to follow displacement of the protein x-linker as ligand is titrated and provides a dissociation constant of 23 ± 4 ?M

The levels of trypsinogen isoenzymes in ovarian tumour cyst fluids are associated with promatrix metalloproteinase-9 but not promatrix metalloproteinase-2 activation

Proteolysis mediated by matrix metalloproteinases (MMPs) and serine proteinases is associated with cancer invasion and metastasis. Activation of latent proMMPs, and especially the proforms of the type IV collagen degrading gelatinases A and B (proMMP-2 and proMMP-9), is thought to be a critical step in this process. We have recently found that human tumour-associated trypsin-2 is a potent activator of proMMP-9 and it also activates proMMP-2 in vitro. Trypsinogen, MMP-2, and MMP-9 are expressed in ovarian cancer. To elucidate the function of trypsin in vivo, we studied whether high concentrations of trypsinogen-1, trypsinogen-2, their α1-proteinase inhibitor (API) complexes, and tumour-associated trypsin inhibitor (TATI) are associated with proMMP-2 and proMMP-9 activation in ovarian tumour cyst fluids. Zymography and immunofluorometric analysis of 61 cyst fluids showed a significant association between high trypsin concentrations and the activation of MMP-9 (P= 0.003–0.05). In contrast, the trypsin concentrations were inversely associated with the activation of MMP-2 (P= 0.01–0.02). Immunohistochemical analysis of ovarian tumour tissue demonstrated expression of trypsinogen-2 and TATI in the secretory epithelium. MMP-2 was detected both in stromal and epithelial cells whereas MMP-9 was detected in neutrophils and macrophage-like cells in stromal and epithelial areas. These results suggest that trypsin may play a role in the regulation of the MMP-dependent proteolysis associated with invasion and metastasis of ovarian cancer. © 2001 Cancer Research Campaign www.bjcancer.co

Use of in vivo phage display to engineer novel adenoviruses for targeted delivery to the cardiac vasculature

We performed in vivo phage display in the stroke prone spontaneously hypertensive rat, a cardiovascular disease model, and the normotensive Wistar Kyoto rat to identify cardiac targeting peptides, and then assessed each in the context of viral gene delivery. We identified both common and strain-selective peptides, potentially indicating ubiquitous markers and those found selectively in dysfunctional microvasculature of the heart. We show the utility of the peptide, DDTRHWG, for targeted gene delivery in human cells and rats in vivo when cloned into the fiber protein of subgroup D adenovirus 19p. This study therefore identifies cardiac targeting peptides by in vivo phage display and the potential of a candidate peptide for vector targeting strategies