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Journal articles on the topic 'Marker detection'
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Ferreira, Ines, Sarah Lepuschitz, Stephan Beisken, et al. "Culture-Free Detection of Antibiotic Resistance Markers from Native Patient Samples by Hybridization Capture Sequencing." Microorganisms 9, no. 8 (2021): 1672. http://dx.doi.org/10.3390/microorganisms9081672.
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The increasing incidence of antimicrobial resistance (AMR) is a major global challenge. Routine techniques for molecular AMR marker detection are largely based on low-plex PCR and detect dozens to hundreds of AMR markers. To allow for comprehensive and sensitive profiling of AMR markers, we developed a capture-based next generation sequencing (NGS) workflow featuring a novel AMR marker panel based on the curated AMR database ARESdb. Our primary objective was to compare the sensitivity of target enrichment-based AMR marker detection to metagenomics sequencing. Therefore, we determined the limit of detection (LOD) in synovial fluid and urine samples across four key pathogens. We further demonstrated proof-of-concept for AMR marker profiling from septic samples using a selection of urine samples with confirmed monoinfection. The results showed that the capture-based workflow is more sensitive and requires lower sequencing depth compared with metagenomics sequencing, allowing for comprehensive AMR marker detection with an LOD of 1000 CFU/mL. Combining the ARESdb AMR panel with 16S rRNA gene sequencing allowed for the culture-free detection of bacterial taxa and AMR markers directly from septic patient samples at an average sensitivity of 99%. Summarizing, the newly developed ARESdb AMR panel may serve as a valuable tool for comprehensive and sensitive AMR marker detection.
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Brbaklic, L., D. Trkulja, A. Kondic-Spika, S. Treskic, and B. Kobiljski. "Detection of QTLs for important agronomical traits in hexaploid wheat using association analysis." Czech Journal of Genetics and Plant Breeding 49, No. 1 (2013): 1–8. http://dx.doi.org/10.17221/64/2012-cjgpb.
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One of the main wheat breeder’s goals is determining specific genomic regions which control important agronomical traits. Association analysis is a new strategy with high resolution in plant molecular breeding that could be used to improve the efficiency of marker assisted selection (MAS) for finding important QTLs (quantitative trait loci) or genes. A set of 96 diverse wheat genotypes was phenotypically measured during three growing seasons (2006/07, 2007/08, 2008/09). Microsatellite markers located near important QTLs were carefully chosen in accordance with existing literature data to validate marker trait associations (MTA). Genomic DNA was extracted using the CTAB method and PCR products were separated by capillary electrophoresis. The population structure was assigned based on molecular data in Structure v. 2.0 software, while association analysis was done by the Tassel program using the Q matrix. Nine significant associations were stable in all years investigated and eight MTA were detected to be significant in two growing seasons. Microsatellite markers which showed significant associations and stability in different seasons can be useful and suitable for marker assisted selection (MAS) in Serbian wheat breeding programs.  
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Jeon, Kwang Myung, Chan Jun Chun, Hong Kook Kim, and Myung J. Lee. "User-Aware Audio Marker Using Low Frequency Ultrasonic Object Detection and Communication for Augmented Reality." Applied Sciences 9, no. 10 (2019): 2004. http://dx.doi.org/10.3390/app9102004.
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In augmented reality (AR), audio markers can be alternatives to image markers for rendering virtual objects when an AR device camera fails to identify the image marker due to lighting conditions and/or the distance between the marker and device. However, conventional audio markers simply broadcast a rendering queue to anonymous devices, making it difficult to provide specific virtual objects of interest to the user. To overcome this limitation without relying on camera-based sensing, we propose a user-aware audio marker system using low frequency ultrasonic signal processing. The proposed system detects users who stay within the marker using ultrasonic-based object detection, and then it uses ultrasonic communication based on windowed differential phase shift keying modulation in order to send a rendering queue only to those users near the marker. Since the proposed system uses commercial microphones and speakers, conventional telecommunication systems can be employed to deliver the audio markers. The performance of the proposed audio marker system is evaluated in terms of object detection accuracy and communication robustness. First, the object detection accuracy of the proposed system is compared with that of a pyroelectric infrared (PIR) sensor-based system in indoor environments, and it is shown that the proposed system achieves a lower equal error rate than the PIR sensor-based system. Next, the successful transmission rate of the proposed system is measured for various distances and azimuths under noisy conditions, and it is also shown that the proposed audio marker system can successfully operate up to approximately 4 m without any transmission errors, even with 70 dBSPL ambient noise.
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Cherkasova, Olga, Yan Peng, Maria Konnikova, et al. "Diagnosis of Glioma Molecular Markers by Terahertz Technologies." Photonics 8, no. 1 (2021): 22. http://dx.doi.org/10.3390/photonics8010022.
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This review considers glioma molecular markers in brain tissues and body fluids, shows the pathways of their formation, and describes traditional methods of analysis. The most important optical properties of glioma markers in the terahertz (THz) frequency range are also presented. New metamaterial-based technologies for molecular marker detection at THz frequencies are discussed. A variety of machine learning methods, which allow the marker detection sensitivity and differentiation of healthy and tumor tissues to be improved with the aid of THz tools, are considered. The actual results on the application of THz techniques in the intraoperative diagnosis of brain gliomas are shown. THz technologies’ potential in molecular marker detection and defining the boundaries of the glioma’s tissue is discussed.
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Alonzo, Todd A., and Kimberly D. Siegmund. "Statistical Methods for Evaluating DNA Methylation as a Marker for Early Detection or Prognosis." Disease Markers 23, no. 1-2 (2007): 113–20. http://dx.doi.org/10.1155/2007/308573.
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We summarize standard and novel statistical methods for evaluating the classification accuracy of DNA methylation markers. The choice of method will depend on the type of marker studied (qualitative/quantitative), the number of markers, and the type of outcome (time-invariant/time-varying). A minimum of two error rates are needed for assessing marker accuracy: the true-positive fraction and the false-positive fraction. Measures of association that are computed from the combination of these error rates, such as the odds ratio or relative risk, are not informative about classification accuracy. We provide an example of a DNA methylation marker that is strongly associated with time to death (logrankp= 0.0003) that is not a good classifier as evaluated by the true-positive and false-positive fractions. Finally, we would like to emphasize the importance of study design. Markers can behave differently in different groups of individuals. It is important to know what factors may affect the accuracy of a marker and in which subpopulations the marker may be more accurate. Such an understanding is extremely important when comparing marker accuracy in two groups of subjects.
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Li, Xingxing. "Bayer Marker Detection based on Yolov3." IOP Conference Series: Earth and Environmental Science 440 (March 19, 2020): 022051. http://dx.doi.org/10.1088/1755-1315/440/2/022051.
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Mealy, K., J. Feely, I. Reid, J. McSweeney, T. Walsh, and T. P. J. Hennessy. "Tumour marker detection in oesophageal carcinoma." European Journal of Surgical Oncology (EJSO) 22, no. 5 (1996): 505–7. http://dx.doi.org/10.1016/s0748-7983(96)92998-4.
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Ab Ghani, Hadhrami, Rosli Besar, Zamani Md Sani, et al. "Advances in lane marking detection algorithms for all-weather conditions." International Journal of Electrical and Computer Engineering (IJECE) 11, no. 4 (2021): 3365. http://dx.doi.org/10.11591/ijece.v11i4.pp3365-3373.
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Driving vehicles in all-weather conditions is challenging as the lane markers tend to be unclear to the drivers for detecting the lanes. Moreover, the vehicles will move slower hence increasing the road traffic congestion which causes difficulties in detecting the lane markers especially for advanced driving assistance systems (ADAS). Therefore, this paper conducts a thorough review on vision-based lane marking detection algorithms developed for all-weather conditions. The review methodology consists of two major areas, which are a review on the general system models employed in the lane marking detection algorithms and a review on the types of weather conditions considered for the algorithms. Throughout the review process, it is observed that the lane marking detection algorithms in literature have mostly considered weather conditions such as fog, rain, haze and snow. A new contour-angle method has also been proposed for lane marker detection. Most of the research work focus on lane detection, but the classification of the types of lane markers remains a significant research gap that is worth to be addressed for ADAS and intelligent transport systems.
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Gomes, Luiz Humberto, Keila Maria Roncato Duarte, Felipe Gabriel Andrino, Ana Maria Brancalion Giacomelli, and Flavio Cesar Almeida Tavares. "A vector carrying the GFP gene (Green fluorescent protein) as a yeast marker for fermentation processes." Scientia Agricola 57, no. 4 (2000): 713–16. http://dx.doi.org/10.1590/s0103-90162000000400018.
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Contaminant yeasts spoil pure culture fermentations and cause great losses in quality and product yields. They can be detected by a variety of methods although none being so efficient for early detection of contaminant yeast cells that appear at low frequency. Pure cultures bearing genetic markers can ease the direct identification of cells and colonies among contaminants. Fast and easy detection are desired and morphological markers would even help the direct visualization of marked pure cultures among contaminants. The GFP gene for green fluorescent protein of Aquorea victoria, proved to be a very efficient marker to visualize transformed cells in mixed populations and tissues. To test this marker in the study of contaminated yeast fermentations, the GFP gene was used to construct a vector under the control of the ADH2 promoter (pYGFP3). Since ADH2 is repressed by glucose the expression of the protein would not interfere in the course of fermentation. The transformed yeasts with the vector pYGFP3 showed high stability and high bioluminescence to permit identification of marked cells among a mixed population of cells. The vector opens the possibility to conduct further studies aiming to develop an efficient method for early detection of spoilage yeasts in industrial fermentative processes.
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Kim, Dong Su, Won Sik Ham, Won Sik Jang, et al. "Scale-Up Evaluation of a Composite Tumor Marker Assay for the Early Detection of Renal Cell Carcinoma." Diagnostics 10, no. 10 (2020): 750. http://dx.doi.org/10.3390/diagnostics10100750.
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The early detection of renal cell carcinoma (RCC) using tumor markers remains an attractive prospect for the potential to downstage the disease. To validate the scale-up clinical performance of potential tumor markers for RCC (as a single marker and as a composite tumor marker composed of nicotinamide N-methyltransferase (NNMT), L-Plastin (LCP1), and non-metastatic cells 1 protein (NM23A)), the scale-up assay was performed. Patients with RCC from multiple domestic institutes were included in the clinical evaluation for reassessment and improvement of the established triple markers of our product. For the diagnostic performance of the composite markers, the best-split cutoff points of each marker (147 pg/mL for NNMT, 1780 pg/mL for LCP1, and 520 pg/mL for NM23A) were installed. Serum levels of NNMT, LCP1, and NM23A were greatly increased in subjects with RCC (p < 0.0001). In 1042 blind sample tests with control individuals (n = 500) and patients with RCC (n = 542), the diagnostic sensitivity and specificity of the composite three-marker assay were 0.871 and 0.894, respectively, and the resulting AUC (Area under Curve) of ROC (Receiver Operating Characteristic) was 0.917. As a single marker, the diagnostic accuracies of NNMT, LCP1, and NM23A, as estimated by ROC, were 0.833, 0.844, and 0.601, respectively. The composite three-marker assay with NNMT, LCP1, and NM23A is a more improved novel serum marker assay for the early detection of RCC in cases of renal mass or unknown condition. The NNMT, LCP1, and NM23A triple marker assay could be a powerful diagnostic tumor marker assay to screen the early stage of RCC.
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Todenhöfer, Tilman, Michele Lodde, Kim van Kessel, Renate Pichler, Antonia Vlahou, and Yair Lotan. "Urinary-Based Markers for Bladder Cancer Detection." Société Internationale d’Urologie Journal 1, no. 1 (2020): 49–61. http://dx.doi.org/10.48083/kqgp2151.
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Background The use of urine markers for diagnosis and surveillance has been a topic of broad interest and ongoing controversies in the management of patients with bladder cancer. There has been a constant quest for markers that demonstrate clinical utility. Aim In the framework of the International Consultation on Urological Diseases 2019 on Molecular Biomarkers in Urologic Oncology, a comprehensive review of literature on urinary biomarkers for bladder cancer has been performed. Results Currently available urinary markers include protein-based markers, RNA-based markers, and DNA-based markers. The introduction of high-throughput analysis technologies provides the opportunity to assess multiple parameters within a short period of time, which is of interest for RNA-based, DNA-based, and protein-based marker systems. A comprehensive analysis of molecular alterations in urine samples of bladder cancer patients may be of interest not only for diagnosis and surveillance but also for non-invasive longitudinal assessment of molecular, potentially therapy-relevant, alterations. However, most systems lack prospective validation within well-designed trials and have not been broadly implemented in daily clinical practice. Conclusions Because of limited data from prospective trials, the routine use of any urine marker except cytology is not considered as standard of care in international guidelines. There is an urgent need for prospective trials of urine markers to answer specific clinical questions.
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Dopico, Pablo J., Henrietta Fasanya, Dietmar W. Siemann, and Hugh Z. Fan. "2090 TL1 team approach to osteosarcoma cell detection." Journal of Clinical and Translational Science 2, S1 (2018): 33. http://dx.doi.org/10.1017/cts.2018.140.
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OBJECTIVES/SPECIFIC AIMS: The objective of our collaboration is to develop a strong transdisciplinary team consisting of microfluidics engineers, cancer biologists, and clinicians, to identify cell surface markers capable of detecting circulating osteosarcoma cells (COC) using microfluidic devices. Our goals are 3-fold: (1) Identify cell surface markers unique to osteosarcoma (OS) for COC isolation, (2) develop a Geometrically Enhanced Mixing (GEM) device to isolate COCs, and (3) Evaluate the efficacy of GEM device to detect COCs in OS patients under treatment. The long-term goal is to utilize this cell detection approach to correlate the presence of COC with metastatic incidence. METHODS/STUDY POPULATION: To identify a marker to capture COCs we are utilizing flow cytometry and microfluidic capture devices. Flow cytometry will be used to evaluate the relative expression of epithelial cell adhesion molecule (EpCAM), CD45, cell surface vimentin (CSV), insulin-like growth factor 2 (IGF2R), interleukin 11 receptor subunit alpha (IL-11Rɑ), ganglioside 2 (GD2), and receptor activator of nuclear factor κ-B (RANK) on a panel of OS cell lines. These cell surface markers were selected based on an extensive review of OS cell surface markers. OS cell capture efficacy will be assessed by passaging a known concentration of OS cells through a GEM microfluidic device coated with antibodies targeting the selected marker, as indicated by flow cytometry. Once captured, COCs on the device will be analyzed and the capture efficiency for the indicated marker will be measured. ANOVA will be used to determine any significant difference in capture efficiency between marker types. Once an optimal marker or panel of markers has been selected we will conduct capture studies using OS cell spiked blood samples followed by clinical samples obtained from OS patients. In clinical samples, COC detection will be validated using the FDA approved triple immunocytochemistry technical definition of a circulating tumor cell (CTC). This will enable COCs to be differentiated from the normal whole blood cell population by selecting for CD45−, EpCAM+, and cytokeratin+ cells. RESULTS/ANTICIPATED RESULTS: Our preliminary studies have shown that on our microfluidic device, EpCAM, a marker commonly used to identify circulating tumor cells in other cancer settings, has a poor capture efficiency (15.9%+7.7%) for HU09 OS cells while the same setup with EpCAM has a capture efficiency of 56.9%+2.7% for BXPc-3 pancreatic cells. We therefore anticipate our flow cytometry studies to show a low expression of EpCAM and CD45 for OS cell lines, while showing a moderate to high expression of CSV, IGF2R, IL-11Rɑ, GD2, and RANK. We expect to show a 60%–80% capture efficiency for markers selected for COC capture. Currently, CSV and GD2 are particularly promising as markers based on previously published studies. DISCUSSION/SIGNIFICANCE OF IMPACT: OS is the most common primary bone tumor and the third leading cause of pediatric cancer deaths. At diagnosis 80% of patients will present with metastasis, however only 20% of these cases are clinically detectable. Innovative strategies to identify patients at risk of metastasis would allow for stratification of intervention therapies. Currently, tumor recurrence and metastasis are primarily dependent on diagnostic-imaging modalities such as computerized tomography or positron emission tomography scans. Unfortunately, these imaging modalities can only detect tumor masses of significant size (106 tumor cells). Liquid biopsies are a novel alternative to current diagnostic imaging systems to monitor metastatic incidence and treatment efficacy. The detection of CTCs through routine blood sampling has the potential to be used clinically for earlier detection, monitoring the treatment of metastatic cancers and surveying the effect of therapeutic interventions on metastasis. To date, the majority of the studies on CTCs have evaluated their presence in carcinomas. Although sarcomas are rare, they generally have a poor prognosis. This study will address one of the unmet medical needs in the field of CTC detection; the identification of cell surface OS makers to improve binding specificity, increase purity, and maintain a high capture efficiency. This phase of our proposal will evaluate the most abundant and conserved markers across a panel of OS cell lines. Once a marker or panel of markers is selected, we will begin to develop a microfluidic device that can be used clinically to detect CTCs in this disease setting.
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Wang, Shuhang, Brian R. Ott, and Gang Luo. "Detection of Lane-Change Events in Naturalistic Driving Videos." International Journal of Pattern Recognition and Artificial Intelligence 32, no. 10 (2018): 1850030. http://dx.doi.org/10.1142/s0218001418500301.
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Lane changes are important behaviors to study in driving research. Automated detection of lane-change events is required to address the need for data reduction of a vast amount of naturalistic driving videos. This paper presents a method to deal with weak lane-marker patterns as small as a couple of pixels wide. The proposed method is novel in its approach to detecting lane-change events by accumulating lane-marker candidates over time. Since the proposed method tracks lane markers in temporal domain, it is robust to low resolution and many different kinds of interferences. The proposed technique was tested using 490 h of naturalistic driving videos collected from 63 drivers. The lane-change events in a 10-h video set were first manually coded and compared with the outcome of the automated method. The method’s sensitivity was 94.8% and the data reduction rate was 93.6%. The automated procedure was further evaluated using the remaining 480-h driving videos. The data reduction rate was 97.4%. All 4971 detected events were manually reviewed and classified as either true or false lane-change events. Bootstrapping showed that the false discovery rate from the larger data set was not significantly different from that of the 10-h manually coded data set. This study demonstrated that the temporal processing of lane markers is an efficient strategy for detecting lane-change events involving weak lane-marker patterns in naturalistic driving.
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Koch, Christian, Matthias Neges, Markus König, and Michael Abramovici. "Performance Study on Natural Marker Detection for Augmented Reality Supported Facility Maintenance." Australasian Journal of Construction Economics and Building - Conference Series 2, no. 1 (2014): 23. http://dx.doi.org/10.5130/ajceb-cs.v2i1.3767.
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The operation and maintenance phase is the longest and most expensive life-cycle period of building facilities. Operators need to perform activities to provide a comfortable living and working environment and to upkeep equipment to prevent functionality failures. For that purpose they manually browse, sort and select dispersed and unformatted facility information before actually going on the site. Although some software tools have been introduced, they still spent 50% of the on-site work on inspection target localization and navigation. To improve these manual, time consuming and tedious procedures, the authors previously presented a framework that uses BIM-based Augmented Reality (AR) to support facility maintenance tasks. The proposed workflow contains AR supported activities, namely AR-based indoor navigation and AR-based maintenance instructions. An inherent problem of AR is marker definition and detection. As introduced, indoor natural markers such as exit signs, fire extinguisher location signs, and appliances’ labels were identified to be suitable for both navigation and maintenance instructions. However, small markers, changing lighting conditions, low detection frame rates and accuracies might prevent the proposed approach from being practical. In this paper the performance of natural marker detection will be evaluated under different configurations, varying marker types, marker sizes, camera resolutions and lighting conditions. The detection performance will be measured using pre-defined metrics incorporating detection accuracy, tracking quality, frame rates, and robustness. The result will be a set of recommendations on what configurations are most suitable and practical within the given framework.
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Archak, S., A. B. Gaikwad, D. Gautam, E. V. V. B. Rao, K. R. M. Swamy, and J. L. Karihaloo. "Comparative assessment of DNA fingerprinting techniques (RAPD, ISSR and AFLP) for genetic analysis of cashew (Anacardium occidentale L.) accessions of India." Genome 46, no. 3 (2003): 362–69. http://dx.doi.org/10.1139/g03-016.
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Nineteen cashew accessions were analysed with 50 random primers, 12 ISSR primers and 6 AFLP primer pairs to compare the efficiency and utility of these techniques for detecting variation in cashew germplasm. Each marker system could discriminate between all of the accessions, albeit with varied efficiency of polymorphism detection. AFLP exhibited maximum discrimination efficiency with a genotype index of 1. The utility of each molecular marker technique, expressed as marker index, was estimated as a function of average band informativeness and effective multiplex ratio. Marker index was calculated to be more than 10 times higher in AFLP than in RAPD and ISSR. Similarity matrices were determined based on the data generated by molecular and morphometric analyses, and compared for congruency. AFLP displayed no correspondence with RAPD and ISSR. Correlation between ISSR and RAPD similarity matrices was low but significant (r = 0.63; p < 0.005). The similarity matrix based on morphometric markers exhibited no correlation with any of the molecular markers. AFLP, with its superior marker utility, was concluded to be the marker of choice for cashew genetic analysis.Key words: Anacardium occidentale, DNA fingerprinting, RAPD, ISSR, AFLP, morphometric.
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Trampert, Patrick, Sviatoslav Bogachev, Nico Marniok, Tim Dahmen, and Philipp Slusallek. "Marker Detection in Electron Tomography: A Comparative Study." Microscopy and Microanalysis 21, no. 6 (2015): 1591–601. http://dx.doi.org/10.1017/s1431927615015433.
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AbstractWe conducted a comparative study of three widely used algorithms for the detection of fiducial markers in electron microscopy images. The algorithms were applied to four datasets from different sources. For the purpose of obtaining comparable results, we introduced figures of merit and implemented all three algorithms in a unified code base to exclude software-specific differences. The application of the algorithms revealed that none of the three algorithms is superior to the others in all cases. This leads to the conclusion that the choice of a marker detection algorithm highly depends on the properties of the dataset to be analyzed, even within the narrowed domain of electron tomography.
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Lee, Jung-Min, Kyung-Ho Lee, and Dae-Seok Kim. "Mobile-AR Inspection System Based on RF-Marker to Improve Marker Detection." Transactions of the Society of CAD/CAM Engineers 17, no. 3 (2012): 208–15. http://dx.doi.org/10.7315/cadcam.2012.208.
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Krasheninnikov, V. R., O. E. Malenova, and A. S. Yashina. "ALGORITHMS OF CRESCENT STRUCTURE DETECTION IN HUMAN BIOLOGICAL FLUID FACIES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W4 (May 10, 2017): 169–72. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w4-169-2017.
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One of the effective methods of early medical diagnosis is based on the image analysis of human biological fluids. In the process of fluid crystallization there appear characteristic patterns (markers) in the resulting layer (facies). Each marker is a highly probable sign of some pathology even at an early stage of a disease development. When mass health examination is carried out, it is necessary to analyze a large number of images. That is why, the problem of algorithm and software development for automated processing of images is rather urgent nowadays. This paper presents algorithms to detect a crescent structures in images of blood serum and cervical mucus facies. Such a marker indicates the symptoms of ischemic disease. The algorithm presented detects this marker with high probability when the probability of false alarm is low.
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Turner, S. J., G. D. Lewis, and A. R. Bellamy. "Detection of sewage-derived escherichia coli in a rural stream using multiplex PCR and automated DNA detection." Water Science and Technology 35, no. 11-12 (1997): 337–42. http://dx.doi.org/10.2166/wst.1997.0756.
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A randomly amplified polymorphic DNA (RAPD) marker, localised to the glycine decarboxylase gene (gcvP) of Escherichia coli, has shown promise for use as a molecular marker for the identification E. coli isolates of human origin. Characterisation of the RAPD polymorphism has enabled development of target-specific primers for direct PCR detection of E. coli of human origin. A field trial was undertaken to investigate the suitability of the marker for detecting E. coli derived from sewage effluent discharged to a rural stream which already contained a substantial background level E. coli of animal origin. Multiplex PCR was performed on E. coli isolates from each sample site using the marker-specific primers in conjunction with primers directed towards a region of the β-glucuronidase (gusA) gene which served as an internal PCR control. Marker-positive strains were detected in raw sewage, treated effluent, stream water collected from immediately downstream of the effluent discharge and from a small tributary which ran down one side of the treatment plant. However, no marker-positive isolates were detected upstream of the treatment plant, despite the relatively high faecal coliform levels (mean = 3.5×103cfu/100ml) recorded at these sites. Further investigations on the side tributary revealed a possible entry point for sewage from the treatment system. Thus the PCR-based approach described here shows promise for the detection of human faecal contamination in rural environments and may be of use for other environmental applications such as the detection of septic tank leachate in rural catchments.
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Moon, Chang Bae, HyunSoo Kim, HyunYong Kim, et al. "A Fast Way for Alignment Marker Detection and Position Calibration." KIPS Transactions on Software and Data Engineering 5, no. 1 (2016): 35–42. http://dx.doi.org/10.3745/ktsde.2016.5.1.35.
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Zheng, Sheng, Changcai Yang, Bart L. Kaptein, Emile A. Hendriks, Olivier H. J. Koning, and Bangjun Lei. "Support value based stent-graft marker detection." Pattern Recognition 46, no. 3 (2013): 962–75. http://dx.doi.org/10.1016/j.patcog.2012.08.017.
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Handel-Fernandez, L., and V. Vincek. "Early cancer detection by microsatellite marker analysis." Medical Hypotheses 53, no. 2 (1999): 114–17. http://dx.doi.org/10.1054/mehy.1998.0727.
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Novović, Lena, Vladimir Ostojić, Đorđe Starčević, and Vladimir Petrović. "Radiography calibration marker detection using Hough transformation." Telfor Journal 11, no. 1 (2019): 30–34. http://dx.doi.org/10.5937/telfor1901030n.
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Van BERS, N. E. M., R. P. M. A. CROOIJMANS, M. A. M. GROENEN, B. W. DIBBITS, and J. KOMEN. "SNP marker detection and genotyping in tilapia." Molecular Ecology Resources 12, no. 5 (2012): 932–41. http://dx.doi.org/10.1111/j.1755-0998.2012.03144.x.
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Sharma, Priyanka, Adity Chopra, Shilpa Chaudhary, and C. Raman Suri. "Bio-nanomechanical Detection of Diabetic Marker HbA1c." BioNanoScience 2, no. 4 (2012): 179–84. http://dx.doi.org/10.1007/s12668-012-0055-4.
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., Akanchha, Rahul Sinha, Sanjeev Narang, and S. K. Neema. "Detection of Micrometastasis in Lymph Nodes in Various Malignancies Using Immunohistochemical Marker (CK7)." Indian Journal of Pathology: Research and Practice 6, no. 3 (part-1) (2017): 518–22. http://dx.doi.org/10.21088/ijprp.2278.148x.6317.2.
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Malenova, O. E., L. I. Trubnikova, A. S. Yashina, and M. L. Albutova. "Algorithm for detecting spherulite marker in human blood serum facies." Information Technology and Nanotechnology, no. 2391 (2019): 109–13. http://dx.doi.org/10.18287/1613-0073-2019-2391-109-113.
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One of the effective methods of early medical diagnosis is the method of wedge dehydration. It is based on the analysis of facies images. Facia is a thin film of dried human biological fluids. The presence of special structures (markers) indicates various pathologies of the organism at their earliest stages. In this article, the algorithm for detecting spherulite marker on microscopic images of human serum facies is presented. The presence of spherulites on facies is the norm. However, the atypical form of spherulite is a marker of precancerous diseases: uterine fibroids, endometrial hyperplastic processes and the mammary gland. Due to the visual analysis of the marker, its characteristic features were identified. Then algorithmic detection methods for these features were developed. The decision on the probable presence of a marker was made if there was a combination of features of this marker. As a result of the application of the developed algorithm, most images of atypical spherulites were identified.
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Motamed-Khorasani, Afsaneh, Andrea Lee Small-Howard, and Hooman Etemadi. "A new strategy for the early detection of colorectal cancer recurrence." Journal of Clinical Oncology 30, no. 4_suppl (2012): 416. http://dx.doi.org/10.1200/jco.2012.30.4_suppl.416.
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416 Background: Several biological markers have been tested for colorectal cancer (CRC) including CEA; however, they are of limited use for recurrence diagnosis due to low sensitivity. Almost 50% of CRC cases experience recurrence and more than 50% of them have low values not detectable by CEA. Therefore, an effective marker for detection of recurrence will vastly increase the quality of life and survival rate. Onko-Sure is an FDA-cleared blood test that is used for the monitoring of treatment/recurrence of CRC. This ELISA assay measures the accumulation of Fibrin/Fibrinogen Degradation products in the serum using an antibody against the DR-70. The goal of this study was to determine whether the combined usage of DR-70 and CEA will improve the sensitivity for detecting recurrences. Methods: A total of 75 serum samples were retrospectively recruited through a serum bank in two arms including the confirmed healthy control (n=39) and biopsy-confirmed recurrent CRC (n=36) groups. For each patient, the serum sample was tested for DR-70 and CEA concentrations. Results: The results showed sensitivity of 75% and specificity of 58.97% for DR-70 and CEA combined. The cut points were calculated as 1.3ug/ml for DR-70, and 3 or 5ng/ml for CEA for non-smokers and smokers; respectively. For the combined analysis, if either CEA or DR-70 was positive, the test was considered positive and if both tests were negative, the result was considered negative. The sensitivity for the combined test was much better than that of each of the markers alone (35% higher than that of CEA). Conclusions: The combined usage of DR-70 and CEA in monitoring of CRC recurrence showed a significant clinical advantage in terms of sensitivity over each marker alone. Improvement in detection of recurrence has important implications to patient treatment options and prognosis. Should an IVD increase early detection of CRC recurrence when used adjunctively with other available diagnostic markers, the annual deaths due to CRC recurrence could be reduced due to the increase in early detection and the survival rate of those early detections.
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Zhang, Fan, Youping Deng, and Renee Drabier. "Multiple Biomarker Panels for Early Detection of Breast Cancer in Peripheral Blood." BioMed Research International 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/781618.
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Detecting breast cancer at early stages can be challenging. Traditional mammography and tissue microarray that have been studied for early breast cancer detection and prediction have many drawbacks. Therefore, there is a need for more reliable diagnostic tools for early detection of breast cancer due to a number of factors and challenges. In the paper, we presented a five-marker panel approach based on SVM for early detection of breast cancer in peripheral blood and show how to use SVM to model the classification and prediction problem of early detection of breast cancer in peripheral blood. We found that the five-marker panel can improve the prediction performance (area under curve) in the testing data set from 0.5826 to 0.7879. Further pathway analysis showed that the top four five-marker panels are associated with signaling, steroid hormones, metabolism, immune system, and hemostasis, which are consistent with previous findings. Our prediction model can serve as a general model for multibiomarker panel discovery in early detection of other cancers.
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Bink, Marco C. A. M., and Johan A. M. Van Arendonk. "Detection of Quantitative Trait Loci in Outbred Populations With Incomplete Marker Data." Genetics 151, no. 1 (1999): 409–20. http://dx.doi.org/10.1093/genetics/151.1.409.
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Abstract Augmentation of marker genotypes for ungenotyped individuals is implemented in a Bayesian approach via the use of Markov chain Monte Carlo techniques. Marker data on relatives and phenotypes are combined to compute conditional posterior probabilities for marker genotypes of ungenotyped individuals. The presented procedure allows the analysis of complex pedigrees with ungenotyped individuals to detect segregating quantitative trait loci (QTL). Allelic effects at the QTL were assumed to follow a normal distribution with a covariance matrix based on known QTL position and identity by descent probabilities derived from flanking markers. The Bayesian approach estimates variance due to the single QTL, together with polygenic and residual variance. The method was empirically tested through analyzing simulated data from a complex granddaughter design. Ungenotyped dams were related to one or more sons or grandsires in the design. Heterozygosity of the marker loci and size of QTL were varied. Simulation results indicated a significant increase in power when ungenotyped dams were included in the analysis.
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El Amrani, Khadija, Gregorio Alanis-Lobato, Nancy Mah, Andreas Kurtz, and Miguel A. Andrade-Navarro. "Detection of condition-specific marker genes from RNA-seq data with MGFR." PeerJ 7 (May 27, 2019): e6970. http://dx.doi.org/10.7717/peerj.6970.
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The identification of condition-specific genes is key to advancing our understanding of cell fate decisions and disease development. Differential gene expression analysis (DGEA) has been the standard tool for this task. However, the amount of samples that modern transcriptomic technologies allow us to study, makes DGEA a daunting task. On the other hand, experiments with low numbers of replicates lack the statistical power to detect differentially expressed genes. We have previously developed MGFM, a tool for marker gene detection from microarrays, that is particularly useful in the latter case. Here, we have adapted the algorithm behind MGFM to detect markers in RNA-seq data. MGFR groups samples with similar gene expression levels and flags potential markers of a sample type if their highest expression values represent all replicates of this type. We have benchmarked MGFR against other methods and found that its proposed markers accurately characterize the functional identity of different tissues and cell types in standard and single cell RNA-seq datasets. Then, we performed a more detailed analysis for three of these datasets, which profile the transcriptomes of different human tissues, immune and human blastocyst cell types, respectively. MGFR’s predicted markers were compared to gold-standard lists for these datasets and outperformed the other marker detectors. Finally, we suggest novel candidate marker genes for the examined tissues and cell types. MGFR is implemented as a freely available Bioconductor package (https://doi.org/doi:10.18129/B9.bioc.MGFR), which facilitates its use and integration with bioinformatics pipelines.
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Herrmann, Jaqueline, Milen Babic, Markus Tölle, Kai-Uwe Eckardt, Markus van der Giet, and Mirjam Schuchardt. "A Novel Protocol for Detection of Senescence and Calcification Markers by Fluorescence Microscopy." International Journal of Molecular Sciences 21, no. 10 (2020): 3475. http://dx.doi.org/10.3390/ijms21103475.
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Vascular calcification and stiffening of the arterial wall is a systemic phenomenon that is associated with aging and it can be increased by several risk factors. The underlying mechanisms, especially the pathways of cellular senescence, are under current investigation. Easily manageable in vitro settings help to study the signaling pathways. The experimental setting presented here is based on an in vitro model using rat vascular smooth muscle cells and the detection of senescence and osteoblastic markers via immunofluorescence and RNAscope™. Co-staining of the senescence marker p21, the osteoblastic marker osteopontin, detection of senescence-associated heterochromatin foci, and senescence-associated β-galactosidase is possible within one test approach requiring fewer cells. The protocol is a fast and reliable evaluation method for multiplexing of calcifying and senescence markers with fluorescence microscopy detection. The experimental setting enables analysis on single cell basis and allows detection of intra-individual variances of cultured cells.
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Fabisiewicz, Anna, Jadwiga Kulik, Paulina Kober, Elzbieta Brewczyńska, Tadeusz Pieńkowski, and Janusz A. Siedlecki. "Detection of circulating breast cancer cells in peripheral blood by a two-marker reverse transcriptase-polymerase chain reaction assay." Acta Biochimica Polonica 51, no. 3 (2004): 747–55. http://dx.doi.org/10.18388/abp.2004_3559.
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The aim of this study was to use a two-marker assay for the detection of breast cancer cells circulating in patients' blood. We have applied a PCR-based methodology to follow up the possibility of the development of metastatic disease in stage I and II patients who had undergone curative surgery. Since the number of circulating cancer cells in peripheral blood is very low, the technique for their detection needs to be not only highly sensitive, but also very specific. The reverse transcriptase-polymerase chain reaction (RT-PCR) technique may improve the sensitivity of breast cancer cell detection up to only a few cells per one million. The principle of the RT-PCR assay is to amplify a messenger RNA characteristic for breast epithelial cells in a blood sample. Since we do not expect such cells to be circulating in peripheral blood of healthy subjects, detection of the characteristic mRNA should indicate the presence of circulating breast cancer cells. We analyzed the usefulness of three mRNA markers: cytokeratin 19 (CK19), mammaglobin (hMAM) and beta subunit of human chorionic gonadotropin (beta-hCG) for this test. Blood samples (112) were obtained from 55 patients, in stages I and II, with or without metastasis to regional lymph nodes (N0 or N1). We found that a two-marker assay increases the sensitivity of detection of breast cancer cells in comparison with a single-marker one. Combination of two tumor-specific mRNA markers, hMAM/CK19 or beta-hCG/CK19, allowed the detection of circulating breast cancer cells in 65% of N1 patients and 38% of N0 patients. By comparison, the combination hMAM/beta-hCG allowed the detection of circulating breast cancer cells in the blood of 68% of N1 patients and 46% of N0 patients. Addition of the third marker did not significantly increase the detection sensitivity.
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Kann, Lisa, James Han, David Ahlquist, et al. "Improved Marker Combination for Detection of De Novo Genetic Variation and Aberrant DNA in Colorectal Neoplasia." Clinical Chemistry 52, no. 12 (2006): 2299–302. http://dx.doi.org/10.1373/clinchem.2007.070896.
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Abstract Background: The genetic heterogeneity of sporadic colorectal cancer (CRC) makes the choice of genetic markers and sequence variation–detection technologies critical to the performance of screening assays. We have previously described the effectiveness of a CRC assay composed of 22 known variants in KRAS, APC, TP53, and BAT-26 (V1). We introduce a new marker formulation (V2) that includes detection of de novo variation in APC, PIK3CA, and CTNNB1, hypermethylated sequences within SMARCA3 and VIM, and a single-base variation within BRAF. We compared the abilities of the V1 and V2 markers to detect aberrant DNA in colorectal neoplasias. Methods: V1 and V2 marker formulations were used to analyze 144 colorectal tissue samples comprising 50 precancerous adenomas, 94 carcinomas, and 11 nonpathologic tissues. V1 analysis consisted of single-base extension analysis of the 22 V1 variants. V2 analysis consisted of DNA scanning of the APC mutation cluster region, PIK3CA exons 9 and 20, CTNNB1 exon 3, analysis for the BRAF Val600Glu substitution, and methylation-specific PCR analysis of VIM and SMARCA3. Results: The V2 marker formulation had significantly higher sensitivity than the V1 markers for carcinomas (93.6% and 72.3%, respectively; P = 0.0002) and adenomas (92.0% and 62.0%, respectively; P = 0.0006). None of the nonpathologic samples were positive for any marker. Conclusions: We demonstrate improved sensitivity of a new marker formulation (V2) to detect aberrant DNA in CRC and precancerous adenoma tumor tissues.
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Malek, S., G. J. Monteith, and N. M. M. Moens. "The precision and repeatability of a custom-made pointer device for determination of virtual landmarks in canine three-dimensional kinematics." Veterinary and Comparative Orthopaedics and Traumatology 25, no. 02 (2012): 102–8. http://dx.doi.org/10.3415/vcot-11-05-0069.
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SummaryPlacement of markers on anatomical landmarks represents a large source of error in three-dimensional kinematics. Our objectives were to test the accuracy and precision of a custom-made pointer and compare it to conventional skin markers in dogs. The pointer was first assessed by pointing at the surface of a spherical marker of known dimensions and position in space. Secondly, a point located cranio-distally to the lateral epicondyle was marked in 12 canine elbows with a Steinmann pin and reflective markers. Ability to locate a landmark was compared between the pointer and skin-mounted marker. The distance between experimental and true locations was compared between the two methods. A sphere was mathematically fitted through 29 collected points on the spherical marker. Centre, diameter and volume overlap of the fitted sphere were compared to that of the marker. A 0.729 mm bias was found indicating good accuracy. Residual values were small indicating good precision. The average distance between the true and experimental position of the anatomical landmarks were 9.55 ± 4.20 mm and 9.32 ± 3.28 mm for the pointer and the marker respectively. No significant differences were observed between the two methods. The pointer proved to be accurate and reliable for localizing virtual points and was at least equivalent to skin mounted markers for the detection of anatomical landmarks in the dog. It should prove useful in the localization of anatomical landmarks for kinematic analysis.
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Piepho, Hans-Peter, and Hugh G. Gauch. "Marker Pair Selection for Mapping Quantitative Trait Loci." Genetics 157, no. 1 (2001): 433–44. http://dx.doi.org/10.1093/genetics/157.1.433.
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AbstractMapping of quantitative trait loci (QTL) for backcross and F2 populations may be set up as a multiple linear regression problem, where marker types are the regressor variables. It has been shown previously that flanking markers absorb all information on isolated QTL. Therefore, selection of pairs of markers flanking QTL is useful as a direct approach to QTL detection. Alternatively, selected pairs of flanking markers can be used as cofactors in composite interval mapping (CIM). Overfitting is a serious problem, especially if the number of regressor variables is large. We suggest a procedure denoted as marker pair selection (MPS) that uses model selection criteria for multiple linear regression. Markers enter the model in pairs, which reduces the number of models to be considered, thus alleviating the problem of overfitting and increasing the chances of detecting QTL. MPS entails an exhaustive search per chromosome to maximize the chance of finding the best-fitting models. A simulation study is conducted to study the merits of different model selection criteria for MPS. On the basis of our results, we recommend the Schwarz Bayesian criterion (SBC) for use in practice.
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Issa, S., and H. Scharfetter. "Detection and elimination of signal errors due to unintentional movements in biomedical magnetic induction tomography spectroscopy (MITS)." Journal of Electrical Bioimpedance 9, no. 1 (2018): 163–75. http://dx.doi.org/10.2478/joeb-2018-0021.
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Abstract In biomedical MITS, slight unintentional movements of the patient during measurement can contaminate the aimed images to a great extent. This study deals with measurement optimization in biomedical MITS through the detection of these unpredictable movements during measurement and the elimination of the resulting movement artefacts in the images to be reconstructed after measurement. The proposed detection and elimination (D&E) methodology requires marking the surface of the object under investigation with specific electromagnetically perturbing markers during multi-frame measurements. In addition to the active marker concept already published, a new much simpler passive marker concept is presented. Besides the biological signal caused by the object, the markers will perturb the primary magnetic field inducing their own signals. The markers' signals will be used for the detection of any unwanted object movements and the signal frames corrupted thereby. The corrupted signal frames will be then excluded from image reconstruction in order to prevent any movement artefacts from being imaged with the object. In order to assess the feasibility of the developed D&E technique, different experiments followed by image reconstruction and quantitative analysis were performed. Hereof, target movements were provoked during multifrequency, multiframe measurements in the β-dispersion frequency range on a saline phantom of physiological conductivity. The phantom was marked during measurement with either a small single-turn coil, an active marker, or a small soft-ferrite plate, a passive marker. After measurement, the erroneous phantom signals were corrected according to the suggested D&E strategy, and images of the phantom before and after correction were reconstructed. The corrected signals and images were then compared to the erroneous ones on the one hand, and to other true ones gained from reference measurements wherein no target movements were provoked on the other hand. The obtained qualitative and quantitative measurement and image reconstruction results showed that the erroneous phantom signals could be accurately corrected, and the movement artefacts could be totally eliminated, verifying the applicability of the novel D&E technique in measurement optimization in biomedical MITS and supporting the proposed aspects.
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Gallais, A., L. Moreau, and A. Charcosset. "Detection of marker–QTL associations by studying change in marker frequencies with selection." Theoretical and Applied Genetics 114, no. 4 (2006): 669–81. http://dx.doi.org/10.1007/s00122-006-0467-z.
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Staub, Jack E., Gennaro Fazio, Thomas Horejsi, Yael Danin-Poleg, Noa Reis, and Nurit Katzir. "050 Comparative Analysis of Cultivated Melon Groups (Cucumis melo L.) using Random Amplified Polymorphic DNA and Simple Sequence Repeat Markers." HortScience 35, no. 3 (2000): 397B—397. http://dx.doi.org/10.21273/hortsci.35.3.397b.
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Random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers were used to characterize genetic relationships among 46 accessions in two C. melo L. subsp. melo (Cantalupensis, Inodorus) and subsp. agrestis (Conomon and Flexuosus) groups. Genetic distance (GD) estimates were made among and between accessions in four melon market classes [Galia, Ogen, Charentais, and Shipper (European and U.S. types)] of Cantalupensis, one market class of Inodorus (Cassaba and Honey Dew), one accession of Conomon, and one accession of Flexuosus by employing three GD estimators; simple matching coefficient, Jaccard's coefficient, and Nei's distance-D. Differences detected among 135 RAPD bands and 54 SSR bands (products of 17 SSR primers) were used to calculate GD. Band polymorphisms observed with 21 RAPD primers and 7 SSR primers was important in the detection of genetic differences. Estimators of GD were highly correlated (P > 0.0001; rs = 0.64 to 0.99) when comparisons were made between estimation methods within a particular marker system. Lower correlations (P > 0.001; rs = 0.17 to 0.40) were detected between marker systems using any one estimator. The GD of the Conomon and Flexuosus accessions was significantly different from the mean GD of all the market classes examined, and market classes were distinguishable from each other. Although lower coefficients of variation can be attained in the estimation of GD when using RAPDs compared to SSRs, the genetic relationships identified using these markers were generally similar. Results of RAPD marker analysis suggest that 80 marker bands were adequate for assessing the genetic variation present in the accessions examined.
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Lente, Kornelius, Karin H. Somerlik-Fuchs, Jonas Friedrich Schiemer, et al. "Motility analysis by means of video tracked markers." Current Directions in Biomedical Engineering 4, no. 1 (2018): 341–44. http://dx.doi.org/10.1515/cdbme-2018-0082.
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AbstractThe motility of the gastrointestinal tract is crucial for digestive activity and dysfunction can lead to severe disease pattern. A method for analysing the motility is needed when treatment approaches shall be evaluated. Therefore markers attached to different locations on the stomach and the bowel of pigs are video tracked in this research study. The markers are designed to provide a high contrast and have an adhesive side for fixation. Above the operation field a video camera has been placed to film the markers during the procedure. To analyse the video data a special algorithm has been implemented. The algorithm requires a registration process at the beginning of each recording which allows the parallel tracking of multiple markers. After the registration the algorithm tracks the position of the marker frame by frame. Each frame is converted into a greyscale picture by adding specified colour values of each pixel. This allows emphasizing certain colours. The centre of the marker is determined by computing the horizontal and vertical centre of the marker starting at the corresponding marker position of the previous frame. After completion the data is stored as coordinates and a video with the marker position displayed for further processing. For advanced analysis the data can be synchronized with electromyography signals, for example. The marked videos show a promising tracking of the markers. However, if the algorithm loses track of a marker during a recording, it is unlikely to relocate it due to the successive processing of the frames. Nevertheless this method provides a simple and easy to use solution for movement detection of the gastrointestinal tract.
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Oyafuso, Zack S., Anne E. Baxter, Jason E. Hall, Sean M. Naman, Correigh M. Greene, and Linda D. Rhodes. "Widespread detection of human- and ruminant-origin Bacteroidales markers in subtidal waters of the Salish Sea in Washington State." Journal of Water and Health 13, no. 3 (2015): 827–37. http://dx.doi.org/10.2166/wh.2015.253.
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Rising populations around coastal systems are increasing the threats to marine water quality. To assess anthropogenic fecal influence, subtidal waters were examined monthly for human- and ruminant-sourced Bacteroidales markers at 80 sites across six oceanographic basins of the Salish Sea (Washington State) from April through October, 2011. In the basins containing cities with individual populations &gt;190,000, &gt;50% of sites were positive for the human marker, while in the basins with high densities of dairy and cattle operations, ∼30% of sites were positive for the ruminant marker. Marker prevalence was elevated in spring (April and May) and fall (October) and reduced during summer (June through September), corresponding with seasonal precipitation. By logistic regression, the odds of human marker detection increased with percentage of adjacent catchment impervious surface, dissolved nitrate concentration, and abundance of low nucleic acid bacteria, but decreased with salinity and chlorophyll fluorescence. The odds of ruminant marker detection increased with dissolved ammonium concentration, mean flow rate for the nearest river, and adjacent shoreline length. These relationships are consistent with terrestrial to marine water flow as a transport mechanism. Thus, Bacteroidales markers traditionally used for identifying nearby sources can be used for assessing anthropogenic fecal inputs to regional marine ecosystems.
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Rosado, Tatiana Barbosa, Rafael Simões Tomaz, Marcio Fernandes Ribeiro Junior, et al. "Detection of QTL associated with rust resistance using IBD-based methodologies in exogamic Eucalyptus spp. populations." Crop Breeding and Applied Biotechnology 10, no. 4 (2010): 321–28. http://dx.doi.org/10.1590/s1984-70332010000400006.
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In Brazil the rust caused by Puccinia psidii Winter stands out as the most important disease of eucalyptus. The use of resistant genotypes is the main control method, which makes the detection of markers linked to rust resistance essential to the selection of resistant genotypes. In this study, an F1 progeny of 131 plants from interspecific crossings of Eucalyptus was used to identify markers linked to resistance genes for this pathogen. An integrated map was constructed for linkage group three based on microsatellite markers. For QTL mapping two methodologies based on alleles identical-by-descent (IBD) were used: single marker analysis of Haseman and Elston and the interval mapping procedure of Fulker and Cardon. Both methods showed significant association for the Embra 125 marker.The QTL that explained 42 % of the phenotypic variation was mapped to 0.02 cM of this marker by the Fulker and Cardon. Marker Embra 125 has potential use in assisted selection, thus increasing the efficiency of the selection of resistant genotypes.
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Bethke, Cersten, Henadzi Yakabchuk, Volodymyr Tarasenko, et al. "Detektion superparamagnetischer Marker mittels GMI-Sensorik (Detection of superparamagnetic markers with GMI-Sensors)." tm - Technisches Messen 70, no. 12-2003 (2003): 574–76. http://dx.doi.org/10.1524/teme.70.12.574.20259.
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Watson, R. J., C. Haitas-Crockett, T. Martin, and R. Heys. "Detection of Rhizobium meliloti cells in field soil and nodules by polymerase chain reaction." Canadian Journal of Microbiology 41, no. 9 (1995): 816–25. http://dx.doi.org/10.1139/m95-112.
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A genetically marked Rhizobium meliloti strain, R692, was prepared by insertion of a 1.7-kb DNA segment from Tn903 between the nifHDK and fixABC genes in the nod megaplasmid. This DNA was used as a marker, detectable by polymerase chain reaction (PCR), for the specific identification of bacteria in soil samples and alfalfa nodules. This detection technique was tested by applying different titres of the marked strain to field plots seeded with alfalfa. Samples of soil and nodules were assayed for the presence of the marker DNA fragment by PCR using primers specific to the marker sequence. The experiments revealed that the bacteria could be detected directly in soil containing about 103–104 bacteria/g, but greater sensitivity was prevented by potent PCR inhibitors present in the samples. The titre of the bacteria in the soil decreased rapidly after inoculation, dropping about 10-fold per week. Tests of vertical location of the bacteria in soil cores showed that the bacteria were initially dispersed to a depth of 18 cm, and subsequently retained viability in the top 2–8 cm. As few as 10 marked R. meliloti per gram of soil resulted in its establishment at detectable levels in nodules. Application of about 104–105 bacteria/g soil was sufficient to give the maximum number of nodules per plant and resulted in 70–90% occupancy by the marked strain. Limited movement of the inoculant was detected by analysis of nodules from plants adjacent to the sites where the bacteria were applied, probably by movement in water. The experiments demonstrated the advantages of PCR for the monitoring of marked microorganisms in the environment.Key words: genetically engineered microorganism, PCR inhibitor, nitrogen fixation, nif and fix genes, genetic marker.
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Pagliusi, Sonia R., and Suzanne M. Garland. "International Standard Reagents for HPV Detection." Disease Markers 23, no. 4 (2007): 283–96. http://dx.doi.org/10.1155/2007/591826.
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Humam papillomavirus is the commonest genital viral infection in healthy sexually active subjects, and the presence of chronic or persistent HPV types in genital cells may constitute a prognostic marker of underlying, or predict future HPV-associated diseases. A variety of novel tests for detecting the presence of oncogenic HPV types in biological specimens have been reported. These are based on the various stages of infection and viral life cycle. HPV infects squamous epithelium with expression of various gene products intimately linked to epithelial cell differentiation. Hence, there are basically three classes of detectable markers directly derived from HPVs: molecular markers based on detection of nucleic acid sequences, serological markers based on detection of antibodies against viral proteins, and cellular markers based on detection of proteins expressed intracellularly, upon either infection or carcinogenesis. The nature of various assays and the development of international standard reagents for qualitative and quantitative assessment of assay performance are outlined. There is an increasing demand to develop standard tools to assess the quality of HPV detection systems, for regulatory and clinical management purposes. International standard reagents for HPV will help defining the analytical sensitivity and specificity of various detection methods, and will allow assuring that laboratory services used to evaluate disease burden, HPV vaccines, and cancer prevention strategies are accurate and comparable worldwide. The advancement of prophylactic vaccine candidates against HPV infections and related diseases stresses the increasing importance of HPV assays in monitoring the impact of HPV vaccination on disease burden.
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Eiben, Bernd, and Ralf Glaubitz. "First-trimester Screening: An Overview." Journal of Histochemistry & Cytochemistry 53, no. 3 (2005): 281–83. http://dx.doi.org/10.1369/jhc.4b6420.2005.
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An improvement in prenatal screening for chromosomal defects has been achieved by combining sonography and biochemical markers. Analyzing markers taken from maternal blood such as pregnancy-associated plasma protein A and free β-human chorionic gonadotropin in combination with the ultrasound marker nuchal translucency provides detection rates of 90% for the most important chromosomal anomalies. In addition, nuchal translucency is a marker for severe heart defects. This report discusses the potential of new markers such as the nasal bone.
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Rhodes, Douglas J., Jane Leslie Hayes, and Chris Steiner. "Retention of External and Internal Markers by Southern Pine Beetles (Coleoptera: Scolytidae) During Gallery Construction." Journal of Entomological Science 33, no. 2 (1998): 221–32. http://dx.doi.org/10.18474/0749-8004-33.2.221.
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If retained, markers used in mark-release-recapture studies of bark beetle dispersal could provide valuable tools in the determination of post-dispersal fate. Retention of the internal marker rubidium (Rb) and of the external marker fluorescent powder during egg gallery construction, oviposition, and feeding were quantified at intervals from 0 to 96 h by allowing marked Southern pine beetles, Dendroctonus frontalis Zimmermann, to carry out these activities in untreated host material. Significant differences in Rb concentrations were found between fed and unfed Rb-marked beetles at all intervals after 12 h. Unfed Rb-marked beetles were detectable at all intervals, whereas reliable detection of fed Rb-marked beetles declined with time. Over 90% of fed southern pine beetle marked with fluorescent powder were detectably marked after 96 h, while less than 50% of the Rb-marked beetles were detectable after 72 h. Neither marking technique adversely affected the gallery length or number of eggs produced by marked beetles compared to unmarked beetles allowed to excavate for 96 h. Practical aspects of both techniques are considered.
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Lauc, Gordan, Mirna Flögel, and Werner E. G. Müller. "Biotinylated Carbohydrate Markers -A Novel Tool for Lectin Research." Zeitschrift für Naturforschung C 49, no. 11-12 (1994): 843–48. http://dx.doi.org/10.1515/znc-1994-11-1220.
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One of the key obstacles in lectin research is the lack of specific techniques for their detection. Novel markers, biotin-labeled carbohydrates, could contribute to overcome this problem. Being at least 10 times more sensitive than neoglycoproteins in the membranescreening assays, they also enable direct detection of lectins in complex mixtures. The markers were synthesized by linking biotin to one, and a carbohydrate (galactose or glucose) to the other amino group of (the amino acid) lysine. After synthesis the markers were chromatographically purified on lectin (RCA for galactose marker, ConA for glucose marker) and avidin affinity columns. The applicability of the markers to detect lectins was demonstrated e.g. with sponge extracts (from Geodia cydonium). Following incubation with biotin-labeled carbohydrates covalent cross-linking between lectins and markers was induced by UV radiation. After transfer to the blotting membrane, lectins were detected with deglycosylated antibiotin antibody labeled with alkaline phosphatase. Besides for the cross-linking technique, the biotinylated carbohydrate markers were also used for detection of lectins on the nitrocellulose membrane in gene library screening and slot blotting.
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Onishi, Kosuke, Daisuke Tanaka, and Shiyuan Yang. "3D Position Detection Using a 2D PSD and a Marker Composed of Light Sources." Journal of the Institute of Industrial Applications Engineers 4, no. 2 (2016): 86–93. http://dx.doi.org/10.12792/jiiae.4.86.
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Keightley, Peter D., and Grahame Bulfield. "Detection of quantitative trait loci from frequency changes of marker alleles under selection." Genetical Research 62, no. 3 (1993): 195–203. http://dx.doi.org/10.1017/s0016672300031906.
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SummaryA method was developed to estimate effects of quantitative trait loci (QTL) by maximum likelihood using information from changes of gene frequency at marker loci under selection, assuming an additive model of complete linkage between markers and QTL. The method was applied to data from 16 molecular and coat colour marker loci in mouse lines derived from the F2of two inbred strains which were divergently selected on 6-week weight for 21 generations. In 4 regions of the genome, marker allele frequencies were more extreme than could be explained by sampling, implying selection at nearby QTL. An effect of about 0·5 standard deviations was located on chromosome 11, and accounted for nearly 10% of the genetic variance in the base population. QTL with effects as small as 0·2 phenotypic standard deviations could be detected. For typing of a given number of individuals, the power of detection of QTL is very high compared to, for example, analysis of an F2 population. The joint effects of linkage and selection were investigated by Monte Carlo simulation. Marker gene frequencies change little as a consequence of selection at a QTL unless the marker and QTL are less than about 20 cM apart.