The emerging predictive and prognostic role of HER2 in HER2-negative early breast cancer: a retrospective study.

PURPOSE: Many patients with early breast cancer (eBC) undergoing neoadjuvant chemotherapy do not achieve pathological complete response (pCR), which is a prognostic factor. We examined the role of HER2-low expression in predicting pCR and prognosis in HER2-negative eBC. METHODS: We evaluated patients with stage I-III HER2-negative BC, treated between 2013 and 2023 at The Royal Marsden NHS Foundation Trust, London. Tumors were classified based on estrogen receptor (ER) status and into HER2-low and HER2-zero subgroups. We analyzed pCR rates, relapse-free survival (RFS) and overall survival (OS). RESULTS: 754 patients were included in the analysis. pCR rate was 8.9% in the ER+ /HER2-low, 16.5% in the ER+ /HER2-zero, 38.9% in the ER- ER-/HER2-low and 35.9% in the ER-/HER2-zero eBC (p < 0.001). Multivariable analysis showed a significantly lower pCR rate in HER2-low compared to HER2-zero BC in the ER+ subgroup. At a median follow-up of 63.8 months (59.9-67.4), we observed longer OS in HER2-low compared to HER2-zero patients in the overall and in the ER+ population. There was no predictive or prognostic impact of HER2-low status in the ER- population. CONCLUSION: This study supports the interpretation of HER2 status as a possible prognostic and predictive biomarker for HER2-negative eBC, especially among patients with ER+ disease.

Expanding the reach of commercial cell therapies requires changes at medical centers.

The clinical application of cell therapies is becoming increasingly important for the treatment of cancer, congenital immune deficiencies, and hemoglobinopathies. These therapies have been primarily manufactured and used at academic medical centers. However, cell therapies are now increasingly being produced in centralized manufacturing facilities and shipped to medical centers for administration. Typically, these cell therapies are produced from a patient's own cells, which are the critical starting material. For these therapies to achieve their full potential, more medical centers must develop the infrastructure to collect, label, cryopreserve, test, and ship these cells to the centralized laboratories where these cell therapies are manufactured. Medical centers must also develop systems to receive, store, and infuse the finished cell therapy products. Since most cell therapies are cryopreserved for shipment and storage, medical centers using these therapies will require access to liquid nitrogen product storage tanks and develop procedures to thaw cell therapies. These services could be provided by the hospital pharmacy or transfusion service, but the latter is likely most appropriate. Another barrier to implementing these services is the variability among providers of these cell therapies in the processes related to handling cell therapies. The provision of these services by medical centers would be facilitated by establishing a national coordinating center and a network of apheresis centers to collect and cryopreserve the cells needed to begin the manufacturing process and cell therapy laboratories to store and issue the cells. In addition to organizing cell collections, the coordinating center could establish uniform practices for collecting, labeling, shipping, receiving, thawing, and infusing the cell therapy.

Healthcare center-based cell therapy laboratories supporting off-site manufactured cell therapies: The experiences of a single academic cell therapy laboratory.

BACKGROUND: Healthcare center-based cell therapy laboratories (HC CTLs) evolved from solely processing hematopoietic stem cells for transplantation to manufacturing various advanced cellular therapies. With increasing interest in cellular therapy applications, off-site manufactured products are becoming more common. HC CTLs play a critical role in supporting these products by shipping out cellular starting material (CSM) for further manufacturing and/or receiving, storing, and distributing final products. The experiences and challenges encountered by a single academic HC CTL in supporting these products are presented. METHODS: All off-site manufacturing protocols supported before 2023 were reviewed. Collected data included protocol characteristics (treatment indication, product type), process logistics (shipping, receiving, storage, thawing, distribution, documentation), and product handling volumes (CSM shipping and final product infusions). RESULTS: Between 2012 and 2022, 15 off-site manufactured cellular therapy early-phase, single- and multicenter clinical trials were supported. Trials were sponsored by academic/research and commercial entities. The number of protocols supported annually increased each year, with few ending. Products included cancer immunotherapies and gene therapies. Autologous CSM was collected and shipped, while autologous and allogeneic final products were received, stored, thawed, and distributed. Process differences among protocols included CSM shipping conditions, laboratory analyses, final product thaw conditions and procedures, number of treatments, and documentation. DISCUSSION: HC CTLs must contend with several challenges in supporting off-site manufacturing protocols. As demand for cellular therapies increases, stakeholders should collaborate from the early phases of clinical trials to streamline processes and standardize procedures to increase value, improve safety, and reduce the burden on HC CTLs.

Reference gene selection for clinical chimeric antigen receptor T-cell product vector copy number assays.

BACKGROUND AIMS: Reference genes are an essential part of clinical assays such as droplet digital polymerase chain reaction (ddPCR), which measure the number of copies of vector integrated into genetically engineered cells and the loss of plasmids in reprogrammed cells used in clinical cell therapies. Care should be taken to select reference genes, because it has been discovered that there may be thousands of variations in copy number from genomic segments among different individuals. In addition, within the same person in the context of cancer and other proliferative disorders, substantial parts of the genome also can differ in copy number between cells from diseased and healthy people. The purpose of this study was to identify reference genes that could be used for copy number variation analysis of transduced chimeric antigen receptor T cells and for plasmid loss analysis in induced pluripotent stem cells using ddPCR. METHODS: We used The Cancer Genome Atlas (TCGA) to evaluate candidate reference genes. If TCGA found a candidate gene to have low copy number variance in cancer, ddPCR was used to measure the copy numbers of the potential reference gene in cells from healthy subjects, cancer cell lines and patients with acute lymphocytic leukemia, lymphoma, multiple myeloma and human papillomavirus-associated cancers. RESULTS: In addition to the rPP30 gene, which we have has been using in our copy number assays, three other candidate reference genes were evaluated using TCGA, and this analysis found that none of the four gene regions (AGO1, AP3B1, MKL2 and rPP30) were amplified or deleted in all of the cancer cell types that are currently being treated with cellular therapies by our facility. The number of copies of the genes AP3B1, AGO1, rPP30 and MKL2 measured by ddPCR was similar among cells from healthy subjects. We found that AGO1 had copy number alteration in some of the clinical samples, and the number of copies of the genes AP3B1, MKL2 and rPP30 measured by ddPCR was similar among cells from patients with the cancer cell types that are currently being treated with genetically engineered T-cell therapies by our facility. CONCLUSIONS: Based on our current results, the three genes, AP3B1, MKL2 and rPP30, are suitable for use as reference genes for assays measuring vector copy number in chimeric antigen receptor T cells produced from patients with acute leukemia, lymphoma, multiple myeloma and human papillomavirus-associated cancers. We will continue to evaluate AGO1 on our future samples.

Effects of extended transport on cryopreserved allogeneic hematopoietic progenitor cell (HPC) product quality and optimal methods to assess HPC stability.

BACKGROUND: Since the beginning of the COVID-19 pandemic, cryopreservation of hematopoietic progenitor cell (HPC) products has been increasingly used to ensure allogeneic donor graft availability prior to recipient conditioning for transplantation. However, in addition to variables such as graft transport duration and storage conditions, the cryopreservation process itself may adversely affect graft quality. Furthermore, the optimal methods to assess graft quality have not yet been determined. STUDY DESIGN AND METHODS: A retrospective review was performed on all cryopreserved HPCs processed and thawed at our facility from 2007 to 2020, including both those collected onsite and by the National Marrow Donor Program (NMDP). HPC viability studies were also performed on fresh products, retention vials, and corresponding final thawed products by staining for 7-AAD (flow cytometry), AO/PI (Cellometer), and trypan blue (manual microscopy). Comparisons were made using the Mann-Whitney test. RESULTS: For HPC products collected by apheresis (HPC(A)), pre-cryopreservation and post-thaw viabilities, as well as total nucleated cell recoveries were lower for products collected by the NMDP compared to those collected onsite. However, there were no differences seen in CD34+ cell recoveries. Greater variation in viability testing was observed using image-based assays compared to flow-based assays, and on cryo-thawed versus fresh samples. No significant differences were observed between viability measurements obtained on retention vials versus corresponding final thawed product bags. DISCUSSION: Our studies suggest extended transport may contribute to lower post-thaw viabilities, but without affecting CD34+ cell recoveries. To assess HPC viability prior to thaw, testing of retention vials offers predictive utility, particularly when automated analyzers are used.

Pyruvate kinase isoform expression alters nucleotide synthesis to impact cell proliferation.

Metabolic regulation influences cell proliferation. The influence of pyruvate kinase isoforms on tumor cells has been extensively studied, but whether PKM2 is required for normal cell proliferation is unknown. We examine how PKM2 deletion affects proliferation and metabolism in nontransformed, nonimmortalized PKM2-expressing primary cells. We find that deletion of PKM2 in primary cells results in PKM1 expression and proliferation arrest. PKM1 expression, rather than PKM2 loss, is responsible for this effect, and proliferation arrest cannot be explained by cell differentiation, senescence, death, changes in gene expression, or prevention of cell growth. Instead, PKM1 expression impairs nucleotide production and the ability to synthesize DNA and progress through the cell cycle. Nucleotide biosynthesis is limiting, as proliferation arrest is characterized by severe thymidine depletion, and supplying exogenous thymine rescues both nucleotide levels and cell proliferation. Thus, PKM1 expression promotes a metabolic state that is unable to support DNA synthesis.

The need for uniform and coordinated practices involving centrally manufactured cell therapies.

Cellular therapies have become an important part of clinical care. The treatment of patients with cell therapies often involves the collection of autologous cells at the medical center treating the patient, the shipment of these cells to a centralized manufacturing site, and the return of the cryopreserved clinical cell therapy to the medical center treating the patient for storage until infusion. As this activity grows, cell processing laboratories at many academic medical centers are involved with many different autologous products manufactured by several different centralized laboratories. The handling of these products by medical center-based cell therapy laboratories is complicated and resource-intensive since each centralized manufacturing laboratory has unique methods for labeling, storing, shipping, receiving, thawing, and infusing the cells. The field would benefit from the development of more uniform practices. The development of a coordinating center similar to those established to facilitate the collection, shipping, and transplantation of hematopoietic stem cells from unrelated donors would also be beneficial. In summary, the wide range of practices involved with labeling, shipping, freezing, thawing, and infusing centrally manufactured autologous cellular therapies lack efficiency and consistency and puts patients at risk. More uniform practices are needed.

Longitudinal transcriptional analysis of peripheral blood leukocytes in COVID-19 convalescent donors.

BACKGROUND: SARS-CoV2 can induce a strong host immune response. Many studies have evaluated antibody response following SARS-CoV2 infections. This study investigated the immune response and T cell receptor diversity in people who had recovered from SARS-CoV2 infection (COVID-19). METHODS: Using the nCounter platform, we compared transcriptomic profiles of 162 COVID-19 convalescent donors (CCD) and 40 healthy donors (HD). 69 of the 162 CCDs had two or more time points sampled. RESULTS: After eliminating the effects of demographic factors, we found extensive differential gene expression up to 241 days into the convalescent period. The differentially expressed genes were involved in several pathways, including virus-host interaction, interleukin and JAK-STAT signaling, T-cell co-stimulation, and immune exhaustion. A subset of 21 CCD samples was found to be highly "perturbed," characterized by overexpression of PLAU, IL1B, NFKB1, PLEK, LCP2, IRF3, MTOR, IL18BP, RACK1, TGFB1, and others. In addition, one of the clusters, P1 (n = 8) CCD samples, showed enhanced TCR diversity in 7 VJ pairs (TRAV9.1_TCRVA_014.1, TRBV6.8_TCRVB_016.1, TRAV7_TCRVA_008.1, TRGV9_ENST00000444775.1, TRAV18_TCRVA_026.1, TRGV4_ENST00000390345.1, TRAV11_TCRVA_017.1). Multiplexed cytokine analysis revealed anomalies in SCF, SCGF-b, and MCP-1 expression in this subset. CONCLUSIONS: Persistent alterations in inflammatory pathways and T-cell activation/exhaustion markers for months after active infection may help shed light on the pathophysiology of a prolonged post-viral syndrome observed following recovery from COVID-19 infection. Future studies may inform the ability to identify druggable targets involving these pathways to mitigate the long-term effects of COVID-19 infection. TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT04360278 Registered April 24, 2020.

A Cost-Effective and Portable Optical Sensor System to Estimate Leaf Nitrogen and Water Contents in Crops.

Non-invasive determination of leaf nitrogen (N) and water contents is essential for ensuring the healthy growth of the plants. However, most of the existing methods to measure them are expensive. In this paper, a low-cost, portable multispectral sensor system is proposed to determine N and water contents in the leaves, non-invasively. Four different species of plants-canola, corn, soybean, and wheat-are used as test plants to investigate the utility of the proposed device. The sensor system comprises two multispectral sensors, visible (VIS) and near-infrared (NIR), detecting reflectance at 12 wavelengths (six from each sensor). Two separate experiments were performed in a controlled greenhouse environment, including N and water experiments. Spectral data were collected from 307 leaves (121 for N and 186 for water experiment), and the rational quadratic Gaussian process regression (GPR) algorithm was applied to correlate the reflectance data with actual N and water content. By performing five-fold cross-validation, the N estimation showed a coefficient of determination () of 63.91% for canola, 80.05% for corn, 82.29% for soybean, and 63.21% for wheat. For water content estimation, canola showed an of 18.02%, corn showed an of 68.41%, soybean showed an of 46.38%, and wheat showed an of 64.58%. The result reveals that the proposed low-cost sensor with an appropriate regression model can be used to determine N content. However, further investigation is needed to improve the water estimation results using the proposed device.

SoilCam: A Fully Automated Minirhizotron using Multispectral Imaging for Root Activity Monitoring.

A minirhizotron is an in situ root imaging system that captures components of root system architecture dynamics over time. Commercial minirhizotrons are expensive, limited to white-light imaging, and often need human intervention. The implementation of a minirhizotron needs to be low cost, automated, and customizable to be effective and widely adopted. We present a newly designed root imaging system called SoilCam that addresses the above mentioned limitations. The imaging system is multi-modal, i.e., it supports both conventional white-light and multispectral imaging, with fully automated operations for long-term in-situ monitoring using wireless control and access. The system is capable of taking 360° images covering the entire area surrounding the tube. The image sensor can be customized depending on the spectral imaging requirements. The maximum achievable image quality of the system is 8 MP (Mega Pixel)/picture, which is equivalent to a 2500 DPI (dots per inch) image resolution. The length of time in the field can be extended with a rechargeable battery and solar panel connectivity. Offline image-processing software, with several image enhancement algorithms to eliminate motion blur and geometric distortion and to reconstruct the 360° panoramic view, is also presented. The system is tested in the field by imaging canola roots to show the performance advantages over commercial systems.

Assessing the utilization of high-resolution 2-field HLA typing in solid organ transplantation.

HLA typing in solid organ transplantation (SOT) is necessary for determining HLA-matching status between donor-recipient pairs and assessing patients' anti-HLA antibody profiles. Histocompatibility has traditionally been evaluated based on serologically defined HLA antigens. The evolution of HLA typing and antibody identification technologies, however, has revealed many limitations with using serologic equivalents for assessing compatibility in SOT. The significant improvements to HLA typing introduced by next-generation sequencing (NGS) require an assessment of the impact of this technology on SOT. We have assessed the role of high-resolution 2-field HLA typing (HR-2F) in SOT by retrospectively evaluating NGS-typed pre- and post-SOT cases. HR-2F typing was highly instructive or necessary in 41% (156/385) of the cases. Several pre- and posttransplant scenarios were identified as being better served by HR-2F typing. Five different categories are presented with specific case examples. The experience of another center (Temple University Hospital) is also included, whereby 21% of the cases required HR-2F typing by Sanger sequencing, as supported by other legacy methods, to properly address posttransplant anti-HLA antibody issues.

Time interval between antibody investigations among patients who demonstrate serial red cell antibody formation.

BACKGROUND: Current national standards for pretransfusion testing do not address the frequency or optimal time interval to repeat antibody identification testing for patients in whom antibodies have been previously detected. STUDY DESIGN AND METHODS: A retrospective review was performed of patients with existing red blood cell (RBC) antibodies who subsequently developed new antibody specificities. Data were drawn from a single institution where the antibody investigation was repeated if the screen suggested a new antibody or if 14 days had elapsed since the previous investigation. Clinically insignificant or drug-dependent antibodies were excluded. Among cases in which new antibodies were detected within 30 days of a previous sample that already demonstrated existing antibodies, the median and lower 95% confidence intervals for the number of days between the detection of the existing and new antibodies were determined. RESULTS: Over a 9-year period, among 2114 patients with more than 1 antibody, 699 (33%) had serially detected antibodies from separate samples. Among 152 patients whose subsequent antibody was detected within 30 days of the existing antibodies, the median time interval to detection of the new antibody was 13 days. The lower 95% confidence interval was 1 day. By Day 3, 18% of the new antibodies had already appeared. CONCLUSION: In patients who form multiple antibodies, the serial emergence of clinically significant antibodies is common. In some patients, detection of a new specificity occurs in a sample drawn shortly after the sample that demonstrated the first antibody. These results have implications for the frequency of pretransfusion testing.

Electronic patient identification for sample labeling reduces wrong blood in tube errors.

BACKGROUND: Wrong blood in tube (WBIT) errors are a preventable cause of ABO-mismatched RBC transfusions. Electronic patient identification systems (e.g., scanning a patient's wristband barcode before pretransfusion sample collection) are thought to reduce WBIT errors, but the effectiveness of these systems is unclear. STUDY DESIGN AND METHODS: Part 1: Using retrospective data, we compared pretransfusion sample WBIT rates at hospitals using manual patient identification (n = 16 sites; >1.6 million samples) with WBIT rates at hospitals using electronic patient identification for some or all sample collections (n = 4 sites; >0.5 million samples). Also, we compared WBIT rates after implementation of electronic patient identification with preimplementation WBIT rates. Causes and frequencies of WBIT errors were evaluated at each site. Part 2: Transfusion service laboratories (n = 18) prospectively typed mislabeled (rejected) samples (n = 2844) to determine WBIT rates among samples with minor labeling errors. RESULTS: Part 1: The overall unadjusted WBIT rate at sites using manual patient identification was 1:10,110 versus 1:35,806 for sites using electronic identification (p < 0.0001). Correcting for repeat samples and silent WBIT errors yielded overall adjusted WBIT rates of 1:3046 for sites using manual identification and 1:14,606 for sites using electronic identification (p < 0.0001), with wide variation among individual sites. Part 2: The unadjusted WBIT rate among mislabeled (rejected) samples was 1:71 (adjusted WBIT rate, 1:28). CONCLUSION: In this study, using electronic patient identification at the time of pretransfusion sample collection was associated with approximately fivefold fewer WBIT errors compared with using manual patient identification. WBIT rates were high among mislabeled (rejected) samples, confirming that rejecting samples with even minor labeling errors helps mitigate the risk of ABO-incompatible transfusions.

Adaptive-Cognitive Kalman Filter and Neural Network for an Upgraded Nondispersive Thermopile Device to Detect and Analyze Fusarium Spores.

Noises such as thermal noise, background noise or burst noise can reduce the reliability and confidence of measurement devices. In this work, a recursive and adaptive Kalman filter is proposed to detect and process burst noise or outliers and thermal noise, which are popular in electrical and electronic devices. The Kalman filter and neural network are used to preprocess data of three detectors of a nondispersive thermopile device, which is used to detect and quantify Fusarium spores. The detectors are broadband (1 µm to 20 µm), λ 1 (6.09 ± 0.06 µm) and λ 2 (9.49 ± 0.44 µm) thermopiles. Additionally, an artificial neural network (NN) is applied to process background noise effects. The adaptive and cognitive Kalman Filter helps to improve the training time of the neural network and the absolute error of the thermopile data. Without applying the Kalman filter for λ 1 thermopile, it took 12 min 09 s to train the NN and reach the absolute error of 2.7453 × 104 (n. u.). With the Kalman filter, it took 46 s to train the NN to reach the absolute error of 1.4374 × 104 (n. u.) for λ 1 thermopile. Similarly, to the λ 2 (9.49 ± 0.44 µm) thermopile, the training improved from 9 min 13 s to 1 min and the absolute error of 2.3999 × 105 (n. u.) to the absolute error of 1.76485 × 105 (n. u.) respectively. The three-thermopile system has proven that it can improve the reliability in detection of Fusarium spores by adding the broadband thermopile. The method developed in this work can be employed for devices that encounter similar noise problems.

Low Resource Complexity R-peak Detection Based on Triangle Template Matching and Moving Average Filter.

A novel R-peak detection algorithm suitable for wearable electrocardiogram (ECG) devices is proposed with four objectives: robustness to noise, low latency processing, low resource complexity, and automatic tuning of parameters. The approach is a two-pronged algorithm comprising (1) triangle template matching to accentuate the slope information of the R-peaks and (2) a single moving average filter to define a dynamic threshold for peak detection. The proposed algorithm was validated on eight ECG public databases. The obtained results not only presented good accuracy, but also low resource complexity, all of which show great potential for detection R-peaks in ECG signals collected from wearable devices.

Model of dehydration and assessment of moisture content on onion using EIS.

Onion is perishable and thereby subject to drying during unrefrigerated storage. Its moisture content is important to ensure optimum quality in storage. To track and analyze the dynamics of natural dehydration in onion and also to assess its moisture content, noninvasive and nondestructive methods are preferred. One of them is known as electrical impedance spectroscopy (or EIS in short). In the first phase of our experiment, we have used EIS, where we apply alternating current with multiple frequency to the object (onion in this case) and generate impedance spectrum which is used to characterize the object. We then develop an equivalent electrical circuit representing onion characteristics using a computer assisted optimization technique that allows us to monitor the response of onion undergoing natural drying for a duration of 3 weeks. The developed electrical model shows better congruence with the impedance data measured experimentally when compared to other conventional models for plant tissue with a mean absolute error of 0.42% and root mean squared error of 0.55%. In the second phase of our experiment, we attempted to find a correlation between the previous impedance data and the actual moisture content of the onions under test (measured by weighing) and developed a mathematical model. This model will provide an alternative tool for assessing the moisture content of onion nondestructively. Our model shows excellent correlation with the ground truth data with a deterministic coefficient of 0.9767, root mean square error of 0.02976 and sum of squared error of 0.01329. Therefore, our two models will offer plant scientists the ability to study the physiological status of onion both qualitatively and quantitatively.

An educational intervention to improve hand hygiene compliance in Vietnam.

BACKGROUND: Hand hygiene compliance is the basis of infection control programs. In developing countries models to improve hand hygiene compliance to reduce healthcare acquired infections are required. The aim of this study was to determine hand hygiene compliance following an educational program in an obstetric and gynecological hospital in Vietnam. METHODS: Health care workers from neonatal intensive care, delivery suite and a surgical ward from Hung Vuong Hospital, Ho Chi Minh City, Vietnam undertook a 4-h educational program targeting hand hygiene. Compliance was monitored monthly for six months following the intervention. Hand hygiene knowledge was assessed at baseline and after six months of the study. RESULTS: There were 7124 opportunities over 370 hand hygiene recording sessions with 1531 opportunities at baseline and 1620 at 6 months following the intervention. Hand hygiene compliance increased significantly from baseline across all sites (43.6% [95% Confidence interval CI: 41.1-46.1] to 63% [95% CI: 60.6-65.3]; p < 0.0001). Health care worker hand hygiene compliance increased significantly after intervention (p < 0.0001). There were significant improvements in knowledge scores from baseline to 2 months post educational intervention with mean difference standard deviations (SD): 1.5 (2.5); p < 0.001). CONCLUSIONS: A simple educational model was implemented in a Vietnamese hospital that revealed good hand hygiene compliance for an extended period of time. Hand hygiene knowledge increased during the intervention. This hand hygiene model could be used in developing countries were resources are limited.

Artifact Noise Removal Techniques on Seismocardiogram Using Two Tri-Axial Accelerometers.

The aim of this study is on the investigation of motion noise removal techniques using two-accelerometer sensor system and various placements of the sensors on gentle movement and walking of the patients. A Wi-Fi based data acquisition system and a framework on Matlab are developed to collect and process data while the subjects are in motion. The tests include eight volunteers who have no record of heart disease. The walking and running data on the subjects are analyzed to find the minimal-noise bandwidth of the SCG signal. This bandwidth is used to design filters in the motion noise removal techniques and peak signal detection. There are two main techniques of combining signals from the two sensors to mitigate the motion artifact: analog processing and digital processing. The analog processing comprises analog circuits performing adding or subtracting functions and bandpass filter to remove artifact noises before entering the data acquisition system. The digital processing processes all the data using combinations of total acceleration and z-axis only acceleration. The two techniques are tested on three placements of accelerometer sensors including horizontal, vertical, and diagonal on gentle motion and walking. In general, the total acceleration and z-axis acceleration are the best techniques to deal with gentle motion on all sensor placements which improve average systolic signal-noise-ratio (SNR) around 2 times and average diastolic SNR around 3 times comparing to traditional methods using only one accelerometer. With walking motion, ADDER and z-axis acceleration are the best techniques on all placements of the sensors on the body which enhance about 7 times of average systolic SNR and about 11 times of average diastolic SNR comparing to only one accelerometer method. Among the sensor placements, the performance of horizontal placement of the sensors is outstanding comparing with other positions on all motions.

An Ultra-Wideband Frequency System for Non-Destructive Root Imaging.

Understanding the root system architecture of plants as they develop is critical for increasing crop yields through plant phenotyping, and ultra-wideband imaging systems have shown potential as a portable, low-cost solution to non-destructive imaging root system architectures. This paper presents the design, implementation, and analysis of an ultra-wideband imaging system for use in imaging potted plant root system architectures. The proposed system is separated into three main subsystems: a Data Acquisition module, a Data Processing module, and an Image Processing and Analysis module. The Data Acquisition module consists of simulated and experimental implementations of a non-contact synthetic aperture radar system to measure ultra-wideband signal reflections from concealed scattering objects in a pot containing soil. The Data Processing module is responsible for interpreting the measured ultra-wideband signals and producing an image using a delay-and-sum beamforming algorithm. The Image Processing and Analysis module is responsible for improving image quality and measuring root depth and average root diameter in an unsupervised manner. The Image Processing and Analysis module uses a modified top-hat transformation alongside quantization methods based on energy distributions in the image to isolate the surface of the imaged root. Altogether, the proposed subsystems are capable of imaging and measuring concealed taproot system architectures with controlled soil conditions; however, the performance of the system is highly dependent on knowledge of the soil conditions. Smaller roots in difficult imaging conditions require future work into understanding and compensating for unwanted noise. Ultimately, this paper sought to provide insight into improving imaging quality of ultra-wideband (UWB) imaging systems for plant root imaging for other works to be followed.

Multi-Focus Fusion Technique on Low-Cost Camera Images for Canola Phenotyping.

To meet the high demand for supporting and accelerating progress in the breeding of novel traits, plant scientists and breeders have to measure a large number of plants and their characteristics accurately. Imaging methodologies are being deployed to acquire data for quantitative studies of complex traits. Images are not always good quality, in particular, they are obtained from the field. Image fusion techniques can be helpful for plant breeders with more comfortable access plant characteristics by improving the definition and resolution of color images. In this work, the multi-focus images were loaded and then the similarity of visual saliency, gradient, and color distortion were measured to obtain weight maps. The maps were refined by a modified guided filter before the images were reconstructed. Canola images were obtained by a custom built mobile platform for field phenotyping and were used for testing in public databases. The proposed method was also tested against the five common image fusion methods in terms of quality and speed. Experimental results show good re-constructed images subjectively and objectively performed by the proposed technique. The findings contribute to a new multi-focus image fusion that exhibits a competitive performance and outperforms some other state-of-the-art methods based on the visual saliency maps and gradient domain fast guided filter. The proposed fusing technique can be extended to other fields, such as remote sensing and medical image fusion applications.