Analysis and classification of 1H-NMR spectra by multifractal analysis.

The objective of this research focuses on the development of a statistical methodology able to answer the question of whether variation in the intake of sulfur amino acids (SAA) affects the metabolic process. Traditional approaches, which evaluate specific biomarkers after a series of preprocessing procedures, have been criticized as not being fully informative, as well as inappropriate for translation of methodology. Rather than focusing on particular biomarkers, our proposed methodology involves the multifractal analysis that measures the inhomogeneity of regularity of the proton nuclear magnetic resonance (1H-NMR) spectrum by wavelet-based multifractal spectrum.

Early detection of ovarian cancer by wavelet analysis of protein mass spectra.

Accurate and efficient detection of ovarian cancer at early stages is critical to ensure proper treatments for patients. Among the first-line modalities investigated in studies of early diagnosis are features distilled from protein mass spectra. This method, however, considers only a specific subset of spectral responses and ignores the interplay among protein expression levels, which can also contain diagnostic information.

Wavelet-based approach for diagnosing attention deficit hyperactivity disorder (ADHD).

Attention deficit hyperactivity disorder (ADHD) is a common cognitive disorder affecting children. ADHD can interfere with educational, social, and emotional development, so early detection is essential for obtaining proper care. Standard ADHD diagnostic protocols rely heavily on subjective assessments of perceived behavior.

Three-Dimensional Field Optimization Method: Gold-Standard Validation of a Novel Color Doppler Method for Quantifying Mitral Regurgitation.

Background: Accurate diagnosis of mitral regurgitation (MR) severity is central to proper treatment. Although numerous approaches exist, an accurate, gold-standard clinical technique remains elusive. The authors previously reported on the initial development and demonstration of the automated three-dimensional (3D) field optimization method (FOM) algorithm, which exploits 3D color Doppler ultrasound imaging and builds on existing MR quantification techniques.

Characterizing exons and introns by regularity of nucleotide strings.

Background: Translation of nucleotides into a numeric form has been approached in many ways and has allowed researchers to investigate the properties of protein-coding sequences and noncoding sequences. Typically, more pronounced long-range correlations and increased regularity were found in intron-containing genes and in non-transcribed regulatory DNA sequences, compared to cDNA sequences or intron-less genes. The regularity is assessed by spectral tools defined on numerical translates.

A combined evidence Bayesian method for human ancestry inference applied to Afro-Colombians.

Uniparental genetic markers, mitochondrial DNA (mtDNA) and Y chromosomal DNA, are widely used for the inference of human ancestry. However, the resolution of ancestral origins based on mtDNA haplotypes is limited by the fact that such haplotypes are often found to be distributed across wide geographical regions. We have addressed this issue here by combining two sources of ancestry information that have typically been considered separately: historical records regarding population origins and genetic information on mtDNA haplotypes.

Current Efavirenz (EFV) or ritonavir-boosted lopinavir (LPV/r) use correlates with elevate markers of atherosclerosis in HIV-infected subjects in Addis Ababa, Ethiopia.

Background: HIV patients on antiretroviral therapy have shown elevated incidence of dyslipidemia, lipodystrophy, and cardiovascular disease (CVD). Most studies, however, focus on cohorts from developed countries, with less data available for these co-morbidities in Ethiopia and sub-Saharan Africa.

Methods: Adult HIV-negative (n = 36), treatment naïve (n = 51), efavirenz (EFV)-treated (n = 91), nevirapine (NVP)-treated (n = 95), or ritonavir-boosted lopinavir (LPV/r)-treated (n=44) subjects were recruited from Black Lion Hospital in Addis Ababa, Ethiopia.

Whole-body immunoPET reveals active SIV dynamics in viremic and antiretroviral therapy-treated macaques.

The detection of viral dynamics and localization in the context of controlled HIV infection remains a challenge and is limited to blood and biopsies. We developed a method to capture total-body simian immunodeficiency virus (SIV) replication using immunoPET (antibody-targeted positron emission tomography). The administration of a poly(ethylene glycol)-modified, (64)Cu-labeled SIV Gp120-specific antibody led to readily detectable signals in the gastrointestinal and respiratory tract, lymphoid tissues and reproductive organs of viremic monkeys.

Image denoising with 2D scale-mixing complex wavelet transforms.

This paper introduces an image denoising procedure based on a 2D scale-mixing complex-valued wavelet transform. Both the minimal (unitary) and redundant (maximum overlap) versions of the transform are used. The covariance structure of white noise in wavelet domain is established.

Multifractal analysis for nutritional assessment.

The concept of multifractality is currently used to describe self-similar and complex scaling properties observed in numerous biological signals. Fractals are geometric objects or dynamic variations which exhibit some degree of similarity (irregularity) to the original object in a wide range of scales. This approach determines irregularity of biologic signal as an indicator of adaptability, the capability to respond to unpredictable stress, and health.

Biphasic fusion of the murine posterior frontal suture.

Background: Craniosynostosis is the premature fusion of cranial sutures early in development. Mice are commonly used to study the mechanisms driving both normal and pathologic cranial suture development. Despite their frequency of use as a model, the time course of bone formation and mineralization during fusion of mouse posterior frontal suture is not well defined.

Statistically significant contrasts between EMG waveforms revealed using wavelet-based functional ANOVA.

We developed wavelet-based functional ANOVA (wfANOVA) as a novel approach for comparing neurophysiological signals that are functions of time. Temporal resolution is often sacrificed by analyzing such data in large time bins, increasing statistical power by reducing the number of comparisons. We performed ANOVA in the wavelet domain because differences between curves tend to be represented by a few temporally localized wavelets, which we transformed back to the time domain for visualization.

Constructing stochastic models from deterministic process equations by propensity adjustment.

Background: Gillespie's stochastic simulation algorithm (SSA) for chemical reactions admits three kinds of elementary processes, namely, mass action reactions of 0th, 1st or 2nd order. All other types of reaction processes, for instance those containing non-integer kinetic orders or following other types of kinetic laws, are assumed to be convertible to one of the three elementary kinds, so that SSA can validly be applied. However, the conversion to elementary reactions is often difficult, if not impossible.

Age-related differences in the morphology of microdamage propagation in trabecular bone.

Microdamage density has been shown to increase with age in trabecular bone and is associated with decreased fracture toughness. Numerous studies of crack propagation in cortical bone have been conducted, but data in trabecular bone is lacking. In this study, propagation of severe, linear, and diffuse damage was examined in trabecular bone cores from the femoral head of younger (61.

Age-related changes in human trabecular bone: Relationship between microstructural stress and strain and damage morphology.

Accumulation of microdamage in aging and disease can cause skeletal fragility and is one of several factors contributing to osteoporotic fractures. To better understand the role of microdamage in fragility fracture, the mechanisms of bone failure must be elucidated on a tissue-level scale where interactions between bone matrix properties, the local biomechanical environment, and bone architecture are concurrently examined for their contributions to microdamage formation. A technique combining histological damage assessment of individual trabeculae with linear finite element solutions of trabecular von Mises and principal stress and strain was used to compare the damage initiation threshold between pre-menopausal (32-37 years, n=3 donors) and post-menopausal (71-80 years, n=3 donors) femoral cadaveric bone.

Breath analysis by mass spectrometry: a new tool for breast cancer detection?

Breath analysis has received attention as a noninvasive diagnostic tool with increasing research into its potential usefulness. We are investigating the utility of the analysis of breath volatile organic compounds (VOCs) as an effective modality for breast cancer (BC) detection and monitoring by collecting breath samples with a simple portable device to determine whether BC patients have breath VOCs distinct from those in healthy volunteers. We prospectively enrolled 20 healthy volunteers and 20 newly diagnosed stage II-IV BC patients.

Ecological-type inference in matched-pair studies with fixed marginal totals.

This paper applies a Bayesian approach to ecological-type inference in matched-pair studies because traditional methods that assume parallel tables are not directly applicable. The proposed procedure is based on a hierarchical Bayes structure which models information about the within-pair association. The proposed algorithm relies on Markov chain Monte Carlo simulation, recovers the full table, and reports its accuracy in terms of credible sets for the cell counts.

One year of alendronate treatment lowers microstructural stresses associated with trabecular microdamage initiation.

Alendronate, an anti-remodeling agent, is commonly used to treat patients suffering from osteoporosis by increasing bone mineral density. Though fracture risk is lowered, an increase in microdamage accumulation has been documented in patients receiving alendronate, leading to questions about the potentially detrimental effects of remodeling suppression on the local tissue (material) properties. In this study, trabecular bone cores from the distal femur of beagle dogs treated for one year with alendronate, at doses scaled by weight to approximate osteoporotic and Paget's disease treatment doses in humans, were subjected to uniaxial compression to induce microdamage.

Self-similarity in NMR Spectra: An Application in Assessing the Level of Cysteine.

High resolution of NMR spectroscopic data of biosamples are a rich source of information on the metabolic response to physiological variation or pathological events. There are many advantages of NMR techniques such as the sample preparation is fast, simple and non-invasive. Statistical analysis of NMR spectra usually focuses on differential expression of large resonance intensity corresponding to abundant metabolites and involves several data preprocessing steps.