Tool For Quantitative Measurement Research Articles

Field Evaluation and in Situ Stress Testing of the Organic-Diffusive Gradients in Thin-Films Passive Sampler.

The organic-diffusive gradients in thin-films (o-DGT) technique has emerged as a promising aquatic passive sampler that addresses many of the challenges associated with current sampling tools used for measurement of polar organic contaminants. This study represents the first comprehensive field evaluation of the o-DGT in natural surface waters, across a wide suite of polar pharmaceuticals and pesticides. We explore the utility and limitations of o-DGT as a quantitative measurement tool compared to grab sampling and the polar organic chemical integrative sampler (POCIS) across four connected agricultural and wastewater-influenced freshwater systems spanning 600 km from the U.S. border to northern Manitoba, Canada. Overall, the suite of analytes detected with o-DGT and POCIS was similar. Concentrations in water estimated using o-DGT were greater than concentrations estimated from POCIS in 71 of 80 paired observations, and on average, the estimates from o-DGT were 2.3-fold greater than estimates from POCIS. Grab sample concentrations suggested that the systematic underestimation with POCIS were largely a result of sampling rate variation related to flow rate and boundary-layer effects, an issue reported consistently in the POCIS literature. These comprehensive measurements in an agriculturally influenced fast-flowing river, long-term sampling (>40 days) in a large dilute lake system, deployments in wastewaters, and under ice at near-freezing temperatures represent effective stress testing of o-DGT under representative and challenging conditions. Overall, its strong performance and improved accuracy over POCIS supports its use as a robust, quantitative, and sensitive measurement tool for polar organic chemicals in aquatic systems.

Development of a Method to Quantify Abnormal Kinetic and Kinematic Coupling Patterns during Functional Movements in the Paretic Arm and Hand of Individuals with Pediatric Hemiplegia.

A main focus of clinical interventions for adults after a stroke and children with hemiplegia is upper limb motor impairments. Robotic and motion capture technologies have been used to quantify the presence of abnormal joint coupling patterns in the arm and hand in adults who have had a stroke. Similar impairments have been observed clinically in children with hemiplegia, however, quantitative measurement tools tailored for this population are lacking. Here, we describe the integration of haptic robotics, pressure recording, and motion capture designed specifically for use with pediatric participants. Preliminary results demonstrate that these measurement techniques are effective in quantifying deficits in reaching abilities in this population.

Implementation of a new thermal model and static calibration of a wedge-shaped hot-film probe in a constant-temperature mode

Wedge-shaped hot-films are a promising alternative to hot-wires for supersonic free flow disturbance measurements if hot-wires cannot be used due to harsh flow conditions. Up to the present, wedge hot-films could not serve as quantitative tools because of an insufficient modelling of the substrate’s influence on the thermal balance. The present paper shows a static calibration of a wedge-shaped hot-film sensor that is based on a combination of an analytical, a numerical and an experimental approach. The substrate’s impact was analysed by the help of CFD simulations and modelled by a newly introduced substrate factor. The obtained sensitivities were discussed and qualitatively explained compared with standard hot-wires. A quantitative comparison of experimentally detected mass flux fluctuations proved the wedge hot-film data to match similar hot-wire results very well. The presented approach has the potential to upgrade hot-films of various shapes to tools for quantitative fluctuation measurements.

Amplification-Free Detection of Micrornas Related to Clear Cell Renal Cell Carcinoma Utilizing a Novel Nanopore-Based Sensor

MicroRNAs (miRs) are small noncoding RNAs that play an important role in gene regulation. Recent studies have shown the correlation of the miRs expression level to carcinogenesis. Currently, qRT-PCR technology is considered as the ‘gold standard’ for miR detection due to its high sensitivity and specificity. However, this technique requires time-consuming and expensive amplification steps along with labeling and enzymatic reactions. In this work, a new nanopore-based detection scheme utilizing a borosilicate micropipette and an assay of complementary gamma-peptide nucleic acid (γ-PNA) probes conjugated to polystyrene beads have been reported for the detection of miR-204 and miR-210 related to the clear cell Renal Cell Carcinoma (ccRCC). Electroosmotic flow (EOF) was induced as the driving force to transport PNA-beads harboring target miRs to the tip of the pore (sensing zone) which resulted in pore blockades with unique and easily distinguishable serrated shape electrical signals. However, in the case of the control experiments ionic current blockades with right-angled shape were detected. The results showed 1 to 10 fM concentration detection limit and 97.6% detection accuracy in 87 experiments. This simple, PCR-free, and robust platform has a technological appeal to be evolved into a quantitative measurement tool for analysis of miR biomarkers in basic and clinical research by correlating the dwelling time of the particles translocation through the pore with the concentration of the RNA oligomers bound to their surface.

DNA terminal structure-mediated enzymatic reaction for ultra-sensitive discrimination of single nucleotide variations in circulating cell-free DNA.

Sensitive detection of the single nucleotide variants in cell-free DNA (cfDNA) may provide great opportunity for minimally invasive diagnosis and prognosis of cancer and other related diseases. Here, we demonstrate a facile new strategy for quantitative measurement of cfDNA mutations at low abundance in the cancer patients’ plasma samples. The method takes advantage of a novel property of lambda exonuclease which effectively digests a 5′-fluorophore modified dsDNA with a 2-nt overhang structure and sensitively responds to the presence of mismatched base pairs in the duplex. It achieves a limit of detection as low as 0.02% (percentage of the mutant type) for BRAFV600E mutation, NRASQ61R mutation and three types of EGFR mutations (G719S, T790M and L858R). The method enabled identification of BRAFV600E and EGFRL858R mutations in the plasma of different cancer patients within only 3.5 h. Moreover, the terminal structure-dependent reaction greatly simplifies the probe design and reduces the cost, and the assay only requires a regular real-time PCR machine. This new method may serve as a practical tool for quantitative measurement of low-abundance mutations in clinical samples for providing genetic mutation information with prognostic or therapeutic implications.

Phase retrieval in moiré volume computed tomography based on spatial phase shifting by triple-crossed gratings.

Due to its advantages of nonintrusiveness, wide measurement range, and insensitivity to variation, Moiré deflectometry is a powerful tool for quantitative measurement of a flow field's physical parameters such as density and temperature. Moiré volume computed tomography (MVCT), combining the moiré deflectometry and volume optical computed tomography (VOCT), can realize real three-dimensional parameters reconstruction, in which the radial derivatives extraction of the projected phase is of great importance. In this paper, a spatial phase-shifting-interferometry-based MVCT system was proposed to extract the radial shearing phase distribution. The system is simple and compact, and consists of three crossed gratings and lenses, with no wave plates or polarizers introduced. Via using a 4-f system, the optical path was shortened, and four spatial phase-shifting grid moiré projections can be obtained simultaneously. Each grid interferogram was filtered and separated into two linear interferograms in two orthogonal directions. Moreover, a two-step spatial phase-shifting algorithm was applied to obtain the first-order derivative phase in two mutually perpendicular directions, respectively. Simulations were implemented to verify the feasibility and accuracy of the proposed phase retrieval method. The measured results for the radial first-order partial derivative of the phase projection of a propane flame in the experimental VOCT system are presented.

The use of large databases to inform the development of an intestinal scoring system for the poultry industry

There is increasing interest among the poultry industry to develop a comprehensive index that can be used to evaluate overall intestinal health and impact on production performance. The Intestinal Integrity (I2) index is a quantitative measurement tool used to assess the intestinal health of flocks that use the Health Tracking System (HTSi), a global surveillance system developed by Elanco Animal Health that captures flock-level information on health and performance. To generate an I2 index score for a flock, the presence of 23 intestinal health conditions is assessed and recorded, then entered into a mathematical equation. The objective of this study was to use data from the HTSi dataset to investigate the association between health conditions contained within the I2 index and five performance outcomes: average daily gain (ADG), mortality during the first week, feed conversion ratio (FCR), European Production Efficiency Factor (EPEF), and percent livability. At the time of analysis, the HTSi dataset contained information from the years 2006–2015 on 921,646 individual bird necropsy records from over 153,576 flocks at 1,570 broiler production flows across 53 countries. Flock-level production data used for this study were available for a subset of this population, 33,212 total flocks representing 6 US and 4 UK production flows. A separate multivariable linear or logistic regression model, with farm as a random effect, was built for each of the five outcomes mentioned above. All models controlled for clustering of flocks within production flows. Significant associations were found between key performance indicators and ten intestinal conditions (gross E. acervulina, gross E. maxima, microscopic E. maxima, gizzard erosions, roundworms, excessive intestinal fluid, thin intestines, excessive intestinal mucus, feed passage, and necrotic enteritis) and two management parameters (production flow and down time). Results from this study demonstrate that large databases, such as the HTSi database, can be used to inform and evaluate changes that can optimize intestinal health, and hence welfare, productivity, and sustainability of the poultry industry. In addition, large databases can be used for monitoring and benchmarking intestinal health of poultry and informing the development of innovative indices such as the I2 index for scoring intestinal health and providing routine data for its calculation.

Novel method for quantitative and real-time measurements on engine combustion at varying pressure based on the wavelength modulation spectroscopy.

The wavelength modulation spectroscopy (WMS) technique has been demonstrated as a powerful and indispensable tool for quantitative and real-time measurements on the combustion process of various industrial devices. However, the varying pressure occurred in the aero-engine combustor significantly affects the accuracy and efficiency of the WMS technique. To address this issue, this work reports a novel method named WMS pressure correction model, which can enable fast signal processing in the measurements at varying pressure. The method was first validated in a heated optical cell, and then applied to the pressure and temperature measurements in an aero-engine combustor. The results show that the new method can efficiently and accurately measure the pressure and temperature at the varying pressure conditions.

FlyLimbTracker: An active contour based approach for leg segment tracking in unmarked, freely behaving Drosophila.

Understanding the biological underpinnings of movement and action requires the development of tools for quantitative measurements of animal behavior. Drosophila melanogaster provides an ideal model for developing such tools: the fly has unparalleled genetic accessibility and depends on a relatively compact nervous system to generate sophisticated limbed behaviors including walking, reaching, grooming, courtship, and boxing. Here we describe a method that uses active contours to semi-automatically track body and leg segments from video image sequences of unmarked, freely behaving D. melanogaster. We show that this approach yields a more than 6-fold reduction in user intervention when compared with fully manual annotation and can be used to annotate videos with low spatial or temporal resolution for a variety of locomotor and grooming behaviors. FlyLimbTracker, the software implementation of this method, is open-source and our approach is generalizable. This opens up the possibility of tracking leg movements in other species by modifications of underlying active contour models.

Structural Complexity in Coral Reefs: Examination of a Novel Evaluation Tool on Different Spatial Scales

1. Structural complexity is a key factor in ecology, often positively linked to biodiversity and carrying capacity of habitats. However, defining quantitatively the ecological role of structural complexity remains a challenge, mainly due to its unclear definition and lack of accurate measurement tools and indices. The most common structural complexity indices used in ecological studies are the Rugosity index and Fractal Dimension. However, these indices cannot appraise, or overlook certain complexity indications that may play important ecological roles, such as the different characteristics of structural elements or different spatial scales of structural complexity. 2. This study attempts to tackle these challenges by: 1. examining a new method for structural complexity measurement (Point-Intercept Contour or PIC), which may allow calculation of different complexity indices; 2. measuring structural complexity on different spatial scales, each of which may affect or reflect on different ecological factors; and 3. comparing three different indices of structural complexity (i.e., Rugosity index, Coefficient of Variation and Neighbor's Distance) at different spatial scales, in natural reefs in the Philippines. 3. The PIC method has proven to be easy to perform, provides informative data about structural complexity elements, and enables the calculation of all three indices on different spatial scales. 4. The different spatial scales revealed different patterns among sites that emphasize the importance of considering spatial scaling when expressing different ecological aspects that may indicate reef health. 5. The three indices showed similar general trends, with some differences between scales that reveal some advantages and some drawbacks to each index. 6. The study demonstrates the importance of structural complexity at different spatial scales, and suggests a series of considerations for the use of relevant methods and indices with emphasis on an inexpensive, facile tool for quantitative structural complexity measurements.

Secretome analysis to elucidate metalloprotease-dependent ectodomain shedding of glycoproteins during neuronal differentiation.

Many membrane proteins are subjected to limited proteolyses at their juxtamembrane regions, processes referred to as ectodomain shedding. Shedding ectodomains of membrane-bound ligands results in activation of downstream signaling pathways, whereas shedding those of cell adhesion molecules causes loss of cell-cell contacts. Secreted proteomics (secretomics) using high-resolution mass spectrometry would be strong tools for both comprehensive identification and quantitative measurement of membrane proteins that undergo ectodomain shedding. In this study, to elucidate the ectodomain shedding events that occur during neuronal differentiation, we establish a strategy for quantitative secretomics of glycoproteins released from differentiating neuroblastoma cells into culture medium with or without GM6001, a broad-spectrum metalloprotease inhibitor. Considering that most of transmembrane and secreted proteins are N-glycosylated, we include a process of N-glycosylated peptides enrichment as well as isotope tagging in our secretomics workflow. Our results show that differentiating N1E-115 neurons secrete numerous glycosylated polypeptides in metalloprotease-dependent manners. They are derived from cell adhesion molecules such as NCAM1, CADM1, L1CAM, various transporters and receptor proteins. These results show the landscape of ectodomain shedding and other secretory events in differentiating neurons and/or during axon elongation, which should help elucidate the mechanism of neurogenesis and the pathogenesis of neurological disorders.

An Exploratory Study on the Possibility of Quantitative Measurement during Abdominal Examinations - A Preliminary Study on the Development of a Diagnostic Device for Abdominal Examinations

Objectives This exploratory trial evaluated the possibility of quantitatively measuring several aspects during the “abdominal examination” of traditional Korean medicine. The main results of this study will be used to develop a new diagnostic device for abdominal examinations. Methods Fifteen healthy volunteers were recruited for this study. Three certified Korean medical doctors assessed the existence of pressure pain, the elasticity of the abdominal muscle, and the tonus at CV12 as gold standards. Then, 2 well-trained investigators measured the pressure pain threshold (PPT), the indentation depth of a bar, and repelling force by pressing CV12. Each investigator measured the above 3 variables 2 times at 1 min intervals using a modified digital algometer. Reliability and validity tests of the 3 variables were performed. Results There were statistically significant coefficients of intraclass correlation on the 3 variables both between and within the investigators (P<0.001). Also, PPT and repelling force showed statistically significant high sensitivity and specificity in a ROC curve. However, the indentation depth of the bar presented relatively low sensitivity. Conclusions This new diagnostic method using a modified digital algometer could be a useful tool for quantitative measurement in “abdominal examinations”. However, future rigorous clinical studies with a large population will be needed for the verification of its usefulness. Keywords: abdominal examination, algometer, reliability, validity, traditional Korean medicine

Metabolomics in Cancer Biomarker Research

As a research tool for quantitative measurement of small molecule metabolites, metabolomics has been devoted to search for biomarkers that can be used for diagnosis and prognosis of malignant tumors. The purpose of this review is to summarize recent literatures on metabolomic-based cancer biomarker research and to discuss the current issues and challenges in the clinical applications of metabolomics technologies. This article reviews metabolomics-based cancer biomarker studies reported in the past 3–5 years, summarizes the classes of potential metabolite markers, and discusses the current problems in study designs as well as analytical platforms and methodologies. The application of metabolomics showed great potential in disease diagnosis, prognosis, and patient stratifications in most types of tumors. In the future, with improvement and standardization of the study designs and analytical protocols, metabolomics can serve as an effective tool for cancer translational research.

The role of acoustic microscopy in bone research

Scanning acoustic microscopy (SAM) has been introduced 3 decades ago with the hope to open a new dimension in the microscopic analysis of biological tissues. However, only during the last decade this technology has emerged from a qualitative imaging modality to a quantitative measurement tool that provides fast and nondestructively elastic maps of acoustic and elastic properties with microscale resolution. Particularly, the spatial registration of parameter maps obtained by SAM with those obtained by complementary modalities, e.g., synchrotron microcomputed tomography, Raman spectroscopy, and inelastic micromechanical testing provided unprecedented inside into structure-composition-function relations, tissue changes with respect to adaptation, ageing, pathologies, and healing. Moreover, elastic maps generated by acoustic microscopy can serve as direct input for numerical simulations. This talk will review the key theoretical principles, experimental clues but also the limitations for the reconstruction of calibrated maps of elastic tissue properties and will present recent findings obtained by correlative imaging and SAM-based numerical sound propagation models. In particular, the role of matrix stiffness heterogeneity as a potential indicator for bone brittleness will be discussed.

A tool for quantitative measurement of proatherogenic heteroplasmic mutations of mitochondrial DNA

A tool for quantitative measurement of proatherogenic heteroplasmic mutations of mitochondrial DNA

Living Well With a Long-Term Condition

The outcomes of self-management interventions are commonly assessed using quantitative measurement tools, and few studies ask people with long-term conditions to explain, in their own words, what aspects of the intervention they valued. In this Grounded Theory study, a Health Trainers service in the north of England was evaluated based on interviews with eight service-users. Open, focused, and theoretical coding led to the development of a preliminary model explaining participants' experiences and perceived impact of the service. The model reflects the findings that living well with a long-term condition encompassed social connectedness, changed identities, acceptance, and self-care. Health trainers performed four related roles that were perceived to contribute to these outcomes: conceptualizer, connector, coach, and champion. The evaluation contributes a grounded theoretical understanding of a personalized self-management intervention that emphasizes the benefits of a holistic approach to enable cognitive, behavioral, emotional, and social adjustments.

Variables associated with communicative participation in Parkinson’s disease and its relationship to measures of health-related quality-of-life

Purpose: Communication disorders associated with Parkinson’s disease (PD) often lead to restricted participation in life roles, yet there is a limited understanding of influencing factors and few quantitative measurement tools available. This study aimed to identify variables associated with communicative participation in PD and to examine the relationship between the Communicative Participation Item Bank (CPIB) and existing health-related quality-of-life (HRQoL) measures.Method: Self-report data from 378 participants with PD from the US and New Zealand were analysed. Data included responses to the CPIB, PD Questionnaire-8, sub-scales of the Global Health instrument from the Patient Reported Outcomes Measurement Information System (PROMIS) and additional self-report instruments.Result: Greater perceived speech disorder, lower levels of speech usage, fatigue, cognitive and emotional problems and swallowing difficulties were associated with lower levels of communicative participation. Participants’ age significantly influenced findings, interacting with country of residence, sex and speech usage. Scores on the CPIB were moderately correlated with HRQoL measures.Conclusion: Communicative participation in PD is complex and influenced by both demographic and disease-based variables, necessitating a broader view of the communicative experiences of those with PD. Measurement of communicative participation as a separate construct to existing HRQoL measures is recommended.

Postural stability in patients with chronic subdural hematoma.

Gait disturbances and falls are common in patients with chronic subdural hematoma (cSDH). Postural stability is mainly visually assessed and has not been described using an objective and quantitative measurement tool. The objective of this prospective study was to evaluate postural stability in cSDH patients by measuring trunk sway during stance and gait compared to healthy elderly (HE). It was also to evaluate the relationships among postural stability and age, hematoma size, brain midline shift and hematoma location. Using a gyroscopic method, trunk sway was measured in 22 cSDH patients preoperatively, 5 postoperatively and 58 HE during seven standing and walking tasks. Trunk sway amplitude and velocity in the anterior-posterior and medial-lateral directions were assessed. Postural stability was reduced in the cSDH group compared to HE for all standing tasks. During gait, the sway angle was increased while velocity was decreased in the cSDH group. Only 18% of the patients could perform all tasks without losing their balance. Postoperatively, postural stability was normalized in the medial-lateral direction during standing. There were no correlations among age, hematoma size, brain midline shift or location of the hematoma and trunk sway. The majority of cSDH patients had reduced postural stability that was partly reversed soon after surgery. It was not correlated to hematoma characteristics, indicating that an increased risk to fall is present regardless of hematoma size and midline shift. This must be accounted for when handling these patients and measures taken to prevent further fall accidents during hospital stays.

A new quantitative image-based method for evaluation of bony temporal hollowing in metopic synostosis

Objective: Premature craniosynostosis is a congenital disorder causing a skull deformity. For both functional and cosmetic reasons, the deformity is surgically treated with a cranioplasty before the age of 1 year. Temporal hollowing is a common and undesirable remaining deformity after cranioplasty for metopic synostosis. The most common method to determine the degree of temporal hollowing is subjective judgement of the temporal region. The aim of the present project was to develop a quantitative semi-automatic computer tool for objective measurement of bony temporal hollowing.Methods: Using MATLAB, a tool was developed to segment computed tomography images, defining the outermost contour. The images were dorsally limited to the widest point of the head. In each case, a sex- and age-matched control was identified and the contours compared. The bony temporal hollowing of the cases was calculated.Results: The intra-user coefficient of variation (CV) was 5.0% (95% CI = 4.2%–6.2%) and the inter-user CV was 3.0% (95% CI = 2.1%–8.6%). For clinical testing purposes, the tool was used in 14 patients, seven of whom had been operated on with a spring-assisted cranioplasty and seven with a cranioplasty using a bone graft.Conclusions: In summary, this study presents a new tool for objective measurement of the surgical result after cranioplasty for metopic synostosis.

Dose–volume histogram evaluation scheme for beam orientations in intensity-modulated radiation therapy

Beam orientations in intensity-modulated radiation therapy (IMRT) is an important, but difficult NP-hard optimization problem. A considerable part of this difficulty is due to the essential prerequisite of defining, appropriately, counter-intuitive criteria for a mathematical plan evaluation that coincides with the clinical judgment of the considered plan. Moreover, the quality of beam directions depends heavily on their intensities. Usually a stochastic selector is utilized for optimizing beam orientations, and the intensities are thus calculated many thousands of times, each time for a different selection of beam directions, resulting in excessive time complexity. Therefore, selecting an appropriate set of beam directions in IMRT is still a time-consuming manual trial-and-error search procedure that depends on intuition and empirical knowledge. To overcome these difficulties, this work utilizes the concept of dose–volume histogram (DVH), which is one of the main recognized quantitative measurement tools used for plan judgment, and presents a DVH evaluation scheme that parallelizes plan evaluation with clinical plan judgment. This scheme is then utilized to optimize the intensities of each individual beam, enabling it to be represented by its DVHs, produced for the different irradiated volumes. Finally, an evolutionary algorithm is employed to search for the best combination of those DVHs reflecting the clinical optimal. The presented methods have been applied to three real clinical examples. In comparison to the standard equally spaced beam plans, improvements were reported in all three cases. In comparison with the greedy algorithm, improvements were reported in those examples requiring more than five beam directions.