HLAMatchmaker is effective for selecting appropriate platelet units for alloimmunised thrombocytopaenic patients who are refractory to random donor platelets.

Background: HLAMatchmaker has been used in the Irish Blood Transfusion Service (IBTS) to select platelets for HLA-alloimmunised, platelet refractory thrombocytopaenic patients since 2006. Although available since 2002, only three studies have been published supporting the programme's effectiveness for this indication.

Objectives: We sought to examine increments to HLA-matched platelets (HMPs) at various matchmaker scores and to examine the impact of transfusing older platelets and ABO-mismatched platelets to this patient group.

Red cell alloimmunisation following intrauterine transfusion and the feasibility of providing extended phenotype-matched red cell units.

Objectives: To analyse the incidence of additional alloantibody formation following intrauterine red cell transfusion and to evaluate the feasibility of providing extended phenotype-matched red cells in future intrauterine transfusion (IUT).

Background: IUT is performed in severe, life-threatening fetal anaemia, usually in alloimmunised pregnancies. Its complications include the formation of additional alloantibodies to other red cell antigens.

ACORN2: new developments of the ACORN concept.

The density-modification procedures incorporated in ACORN, available in the CCP4 package, have proved to be very successful in solving and refining high-resolution crystal structures from very poor starting sets. These can be calculated from a correctly positioned initial fragment containing between 1 and 8% of the scattering power of the total structure. Improvements of ACORN, reported here and incorporated in the program ACORN2, have lowered the size of the fragment required and examples are given of structures solved with only 0.

Simulation of the generation and processing of Doppler ultrasound fetal heart signals to obtain directional motion information.

In fetal heart monitoring using Doppler ultrasound signals the cardiac information is commonly extracted from non-directional signals. As a consequence often some of the cardiac events cannot be observed clearly which may lead to the incorrect detection of the valve and wall motions. Here, directional signals were simulated to investigate their enhancement of cardiac events, and hence provide clearer information regarding the cardiac activities.

Quantitative spectrophotometry of scattering media via frequency-domain and constant-intensity measurements.

The attenuation of light by scattering and absorbing media is nonlinearly dependent upon the absorption coefficient, since detected light has experienced many different flight times. The frequency response of such a sample to modulated light is also nonlinear. We derive an expression for the attenuation that includes both the absorption coefficient and the modulation frequency.

Independent component extraction methods in biosignal processing.

The paper discusses methods for independent source identification within multiple channels electroencephalographical (EEG) signals recordings. The focus is to compare the independent component analysis (ICA) technique to a novel proposed method for individual components separation - the phase space method (PSM). Methods are suitable to be used for any multi-lead signal especially within biomedical signals processing area where independence is a key issue.

ACORN: a review.

The ACORN system was originally developed as a means of ab initio solution of protein structures when atomic resolution data were available. The first step is to obtain a starting set of phases, which must be at least slightly better than random. These may be calculated from a fragment of the structure, which can be anything from a single metal atom to a complete molecular-replacement model.

A modified ACORN to solve protein structures at resolutions of 1.7 A or better.

ACORN has previously been shown to provide an efficient density-modification procedure for the solution of protein structures using diffraction data to better than 1.3 A. The initial phase set could be obtained from a variety of sources such as the position of a heavy atom, a set of scatterers such as S that had been positioned from anomalous dispersion measurements, a fragment or a very low homology model placed from a molecular-replacement search.

New techniques for applying anomalous-scattering and isomorphous-replacement data incorporated in ANOMIR - a general application package.

A computer package ANOMIR is described which can derive phases from anomalous scattering and/or isomorphous-replacement data in any combination. For anomalous scattering it incorporates five methods of applying one-wavelength data and three methods for multiple-wavelength data including SPIN, reported here for the first time. In addition there are three procedures for multiple-wavelength data - the first modifying data for different wavelengths to make them mutually consistent, the second estimating the contributions of the anomalous scatterers alone and the third which finds anomalous differences.

Detrended fluctuation analysis: a suitable method for studying fetal heart rate variability?

We evaluate the suitability of an enhanced detrended fluctuation analysis for studying fetal heart rate series involving imperfect quality of information. Our results indicate that to explore persistent long-range correlations, or fractality, the collection requirements of the data can be relaxed by allowing the possibility of using averaged fetal heart rate series. In addition, it also appears feasible to employ, without producing major alterations in the long-range scaling behaviour, fragmented fetal heart rate series involving up to 50% of random missing values, or up to 50 min of consecutive missing samples in recordings of approximately equal to 8 h length.

Application of region-based segmentation and neural network edge detection to skin lesions.

This paper proposes two approaches to the skin lesion image segmentation problem. The first is a mainly region-based segmentation method where an optimal threshold is determined iteratively by an isodata algorithm. The second method proposed is based on neural network edge detection and a rational Gaussian curve that fits an approximate closed elastic curve between the recognized neural network edge patterns.

Interpretation of heart rate variability via detrended fluctuation analysis and alphabeta filter.

Detrended fluctuation analysis (DFA), suitable for the analysis of nonstationary time series, has confirmed the existence of persistent long-range correlations in healthy heart rate variability data. In this paper, we present the incorporation of the alphabeta filter to DFA to determine patterns in the power-law behavior that can be found in these correlations. Well-known simulated scenarios and real data involving normal and pathological circumstances were used to evaluate this process.

A direct-method ab initio phasing of a protein, cupredoxin amicyanin, at 1.31 A resolution.

The direct-methods program MULTAN88 has been applied successfully to redetermine the structure of a protein, cupredoxin amicyanin, containing 808 non-H atom sites, one Cu atom and 132 ordered water molecules in the asymmetric unit using data at 1.31 A resolution. Starting with initially random phases, useful phase sets selected by figures of merit could be obtained from multiple trials.

Application of empirical mode decomposition to heart rate variability analysis.

The analysis of heart rate variability, involving changes in the autonomic modulation conditions, demands specific capabilities not provided by either parametric or non-parametric spectral estimation methods. Moreover, these methods produce time-averaged power estimates over the entire length of the record. Recently, empirical mode decomposition and the associated Hilbert spectra have been proposed for non-linear and non-stationary time series.

A direct-method ab initio phasing of a protein, pseudoazurin, at 1.55 A resolution.

The direct-method program MULTAN88 has been applied to solve a known protein, pseudoazurin, space group P6(5), unit-cell parameters a = b = 50.0 (1), c = 98.5 (3) A, with 917 protein atoms, a Cu atom and 93 solvent water molecules in the asymmetric unit (>6,000 non-H atoms in the unit cell) and data at 1.

A flexible and efficient procedure for the solution and phase refinement of protein structures.

An ab initio method is described for solving protein structures for which atomic resolution (better than 1.2 A) data are available. The problem is divided into two stages.

On the application of phase relationships to complex structures. XXXVI: some experiments with a small protein without heavy atoms.

The direct-methods program MULTAN88 has been applied to a known protein, ribonuclease (RNAP1), containing 808 non-H atoms, including five S atoms, plus 83 ordered solvent water molecules. Phase sets with mean phase errors between 69 and 75 degrees were selected by modified figures of merit for trials with the full data at 1.17 A resolution and also with restricted data at 1.

Detection of fetal electrocardiogram signals using matched filters with adaptive normalisation.

The authors discuss the application of matched litters to the detection of R-waves in fetal electrocardiogram (FECG) data, recorded during labour using a scalp electrode. When using the basic matched filter, one correlates a template representing the clean signal with the noisy signal. This method is optimal when the underlying noise is white in nature.

Channels in the gramicidin S-with-urea structure and their possible relation to transmembrane ion transport.

The structure of membrane-active antibiotic cyclodecapeptide gramicidin S in the crystals of its complex with urea, C(60)H(92)N(12)0(10).0.(5)[(NH(2))(2)CO].

Direct-space methods in phase extension and phase refinement. VI. PERP (phase extension and refinement program).

Several techniques for extending and refining phases for macromolecular structures have been incorporated into a program package PERP. In addition to previously employed techniques such as solvent flattening and histogram matching, PERP includes a new way of applying the Sayre equation [Refaat, Tate & Woolfson (1995). Acta Cryst.

Direct-space methods in phase extension and phase refinement. V. The histogram moments method.

Any distribution is completely defined by its moments. It is shown that a process of phase refinement can be carried out, based on Fourier transforms, which modifies the moments of electron density, separately in the protein and solvent regions, towards target values. Tests have been carried out on two moderate-sized proteins with 800-900 atoms in the asymmetric unit, one containing heavy atoms and the other not.

Direct-space methods in phase extension and phase refinement. IV. The double-histogram method.

In the conventional histogram-matching technique for phase extension and refinement for proteins a simple one-to-one transformation is made in the protein region to modify calculated density so that it will have some target histogram in addition to solvent flattening. This work describes an investigation where the density modification takes into account not only the current calculated density at a grid point but also some characteristic of the environment of the grid point within some distance R. This characteristic can be one of the local maximum density, the local minimum density or the local variance of density.

Antenatal assessment using the FECG obtained via abdominal electrodes.

During the past decade a variety of intrapartum fetal monitors have been constructed that process the entire fetal electrocardiogram (FECG), obtained via a scalp electrode. They therefore differ from conventional monitors in aiming to extract relevant timing and magnitude information from the morphology of the FECG rather than simply the RR interval and hence heart rate. An intrapartum monitor such as this has been successfully developed by ourselves.

Direct-space methods in phase extension and phase determination. III. Phase refinement using Sayre's equation.

An algorithm is described for refining a set of phases to agree with the Sayre equation. All operations are carried out using Fourier transforms with modest computer-store requirements even for very large systems. The procedure is tested with two moderate-sized proteins, one containing heavy atoms, and is found to give good refinement with data at more than atomic resolution (1.