79 research outputs found
An Integrated Method for Coding Trees, Measuring Tree Diameter, and Estimating Tree Positions
Accurately measuring tree diameter at breast height (DBH) and estimating tree positions in a sample plot are important in tree mensuration. The main aims of this paper include (1) developing a new, integrated device that can identify trees using the quick response (QR) code technique to record tree identifications, measure DBH, and estimate tree positions concurrently; (2) designing an innovative algorithm to measure DBH using only two angle sensors, which is simple and can reduce the impact of eccentric stems on DBH measures; and (3) designing an algorithm to estimate the position of the tree by combining ultra-wide band (UWB) technology and altitude sensors, which is based on the received signal strength indication (RSSI) algorithm and quadrilateral localization algorithm. This novel device was applied to measure ten 10 Ă— 10 m square plots of diversified environments and various tree species to test its accuracy. Before measuring a plot, a coded sticker was fixed at a height of 1.3 m on each individual tree stem, and four UWB module anchors were set up at the four corners of the plot. All individual trees\u27 DBHs and positions within the plot were then measured. Tree DBH, measured using a tree caliper, and the values of tree positions, measured using tape, angle ruler, and inclinometer, were used as the respective reference values for comparison. Across the plots, the decode rate of QR codes was 100%, with an average response time less than two seconds. The DBH values had a bias of 1.89 mm (1.88% in relative terms) and a root mean square error (RMSE) of 5.38 mm (4.53% in relative terms). The tree positions were accurately estimated; the biases on the x-axis and the y-axis of the tree position were -8.55-14.88 cm and -12.07-24.49 cm, respectively, and the corresponding RMSEs were 12.94-33.96 cm and 17.78-28.43 cm. The average error between the estimated and reference distances was 30.06 cm, with a standard deviation of 13.53 cm. The device is cheap and friendly to use in addition to its high accuracy. Although further studies are needed, our method provides a great alternative to conventional tools for improving the efficiency and accuracy of tree mensuration
Liuzijue training improves hypertension and modulates gut microbiota profile
BackgroundLiuzijue training (LZJ) is a traditional exercise integrating breathing meditation and physical exercise, which could prevent and improve hypertension symptoms.PurposeWe aimed to evaluate the therapeutic effect of LZJ on hypertensive patients from the perspectives of blood pressure (BP), vascular endothelial function, immune homeostasis, and gut microbiota.MethodsWe conducted a randomized, controlled, single-blind experiment to assess the effect of 12 weeks LZJ in hypertensive patients. We measured the blood pressure level, vascular endothelial function, serum inflammatory factor concentration, and fecal microbial composition of hypertension patients.ResultsCompared with aerobic training, LZJ has a more significant effect on serum inflammatory factors (IL-6 and IL-10) and gut microbiota. PCoA analysis showed that LZJ tended to transform the gut microbiota structure of hypertensive subjects into that of healthy people. This process involves significant changes in Bacteroides, Clostridium_sensu_stricto_1, Escherichia-Shigella, Haemophilus, Megamonas, and Parabacteroides. In particular, Bacteroides and Escherichia-Shigella, these bacteria were closely related to the improvement of BP in hypertensive patients.ConclusionIn conclusion, our results confirm that LZJ could be used as an adjuvant treatment for hypertensive patients, which could effectively reduce BP, improve the immune homeostasis and gut microbiota structure in patients, and provide a theoretical reference for the use of LZJ in the clinic.Clinical trial registrationhttp://www.chictr.org.cn/listbycreater.aspx, identifier: ChiCTR2200066269
Validation of “Care of the Dying Evaluation” in emergency medicine (CODEEM): pilot phase of End-of-life Management Protocol Offered Within Emergency Room (EMPOWER) study
Background: An increasing number of patients who present to emergency departments are at their endof-life phase and have significant palliative care needs such as in symptom control for pain and dyspnoea. Evaluating quality of care provided is imperative, yet there is no suitable tool validated in the emergency and Asian settings. We aim to examine the face and construct validity, and reliability of a newly developed questionnaire, Care of the Dying Evaluation - Emergency Medicine, for measuring the quality of end-of-life care in an Asian emergency context.
Methods: A mixed methods pilot study was conducted. Participants composed of the next-of-kin to thirty dying patients who presented to the emergency departments of three public hospitals in Singapore. Qualitative evaluation, using cognitive "think-aloud" interviews, and quantitative analysis were employed. Percentage agreement and κ statistic were measured to evaluate temporal stability of the questionnaire. Cronbach's α and item-total correlations were used to assess internal consistency within the constructs. Confirmatory factor analysis was performed for construct validity.
Results: All participants reported clear understanding of the questionnaire with no ambiguity; a minority felt the questions caused emotional distress (7/30, 23.3%). The questions showed moderate to good testretest reliability. Internal consistencies within the constructs were good for "ENVIRONMENT" and "CARE", and moderate for "COMMUNICATION". Factor loadings range from 0.40 to 0.99.
Conclusions: The Care of the Dying Evaluation - Emergency Medicine questionnaire may be valid and reliable for use in an Asian emergency setting. Our prospective multicentre study using this evaluation tool may provide more insight on the quality of care rendered to dying patients and identify areas for improvement.
Trial registration: ClinicalTrials.gov (NCT03906747)
Validation of "Care of the Dying Evaluation" in Emergency Medicine (CODE-EM): pilot phase of end-of-life management protocol offered within emergency room (EMPOWER) study.
BackgroundAn increasing number of patients who present to emergency departments are at their end-of-life phase and have significant palliative care needs such as in symptom control for pain and dyspnoea. Evaluating quality of care provided is imperative, yet there is no suitable tool validated in the emergency and Asian settings. We aim to examine the face and construct validity, and reliability of a newly developed questionnaire, Care of the Dying Evaluation - Emergency Medicine, for measuring the quality of end-of-life care in an Asian emergency context.MethodsA mixed methods pilot study was conducted. Participants composed of the next-of-kin to thirty dying patients who presented to the emergency departments of three public hospitals in Singapore. Qualitative evaluation, using cognitive "think-aloud" interviews, and quantitative analysis were employed. Percentage agreement and κ statistic were measured to evaluate temporal stability of the questionnaire. Cronbach's α and item-total correlations were used to assess internal consistency within the constructs. Confirmatory factor analysis was performed for construct validity.ResultsAll participants reported clear understanding of the questionnaire with no ambiguity; a minority felt the questions caused emotional distress (7/30, 23.3%). The questions showed moderate to good test-retest reliability. Internal consistencies within the constructs were good for "ENVIRONMENT" and "CARE", and moderate for "COMMUNICATION". Factor loadings range from 0.40 to 0.99.ConclusionsThe Care of the Dying Evaluation - Emergency Medicine questionnaire may be valid and reliable for use in an Asian emergency setting. Our prospective multicentre study using this evaluation tool may provide more insight on the quality of care rendered to dying patients and identify areas for improvement.Trial registrationClinicalTrials.gov (NCT03906747)
Identification of different oxygen species in oxide nanostructures with O-17 solid-state NMR spectroscopy
Nanostructured oxides find multiple uses in a diverse range of applications including catalysis, energy storage, and environmental management, their higher surface areas, and, in some cases, electronic properties resulting in different physical properties from their bulk counterparts. Developing structure-property relations for these materials requires a determination of surface and subsurface structure. Although microscopy plays a critical role owing to the fact that the volumes sampled by such techniques may not be representative of the whole sample, complementary characterization methods are urgently required. We develop a simple nuclear magnetic resonance (NMR) strategy to detect the first few layers of a nanomaterial, demonstrating the approach with technologically relevant ceria nanoparticles. We show that the (17)O resonances arising from the first to third surface layer oxygen ions, hydroxyl sites, and oxygen species near vacancies can be distinguished from the oxygen ions in the bulk, with higher-frequency (17)O chemical shifts being observed for the lower coordinated surface sites. H(2)(17)O can be used to selectively enrich surface sites, allowing only these particular active sites to be monitored in a chemical process. (17)O NMR spectra of thermally treated nanosized ceria clearly show how different oxygen species interconvert at elevated temperature. Density functional theory calculations confirm the assignments and reveal a strong dependence of chemical shift on the nature of the surface. These results open up new strategies for characterizing nanostructured oxides and their applications
Comparison of Multiple Machine Learning Models for Estimating the Forest Growing Stock in Large-Scale Forests Using Multi-Source Data
The forest growing stock is one of the key indicators in monitoring forest resources, and its quantitative estimation is of great significance. Based on multi-source data, including Sentinel-1 radar remote sensing data, Sentinel-2 optical remote sensing data, digital elevation model (DEM), and inventory data for forest management planning and design, the Lasso feature selection method was used to remove the non-significant indicators, and three machine learning algorithms, GBDT, XGBoost, and CatBoost, were used to estimate forest growing stock. In addition, four category features, forest population, dominant tree species, humus thickness, and slope direction, were involved in estimating forest growing stock. The results showed that the addition of category features significantly improved the performance of the models. To a certain extent, radar remote sensing data also could improve estimating accuracy. Among the three models, the CatBoost model (R2 = 0.78, MSE = 0.62, MAE = 0.59, MAPE = 16.20%) had the highest estimating accuracy, followed by XGBoost (R2 = 0.75, MSE = 0.71, MAE = 0.62, MAPE = 18.28%) and GBDT (R2 = 0.72, MSE = 0.78, MAE = 0.68, MAPE = 20.28%)
Diagnostic yield of ambulatory oesophageal studies on versus off proton pump inhibitors: a systematic review and meta-analysis
Background: Patients with persistent gastroesophageal reflux disease symptoms despite proton pump inhibitors are increasingly encountered. It remains controversial if proton pump inhibitors should be stopped before functional oesophageal tests. Aim: This meta-analysis compares the positive yield of oesophageal studies performed off versus on proton pump inhibitors. Methods: Pubmed, Embase and the Cochrane Library were searched for eligible studies. Outcomes assessed were the number of subjects with: elevated oesophageal acid exposure time when studied off versus on proton pump inhibitors; positive symptom index (≥50%) and/or positive symptom association probability (≥95%) for acid reflux; and/or non-acid reflux events off versus on proton pump inhibitors. The random effects model was applied. Results: Fifteen studies (n = 5033 individuals; 33% on proton pump inhibitors; 32% men; mean age 52.1 years) were analysed. Pooled risk ratio for the comparison of high oesophageal acid exposure time off versus on proton pump inhibitors was 2.16 (95% confidence interval (CI) 1.42-3.28). The risk ratio of a positive symptom index (acid reflux) was 2.64 (95% CI 1.52-4.57) and the risk ratio of a positive symptom association probability (acid reflux) was 2.94 (95% CI 2.31-3.74). Conversely, the risk ratio of a positive symptom index (non-acid reflux) was 0.96 (95% CI 0.49-1.88) and risk ratio of a positive symptom association probability (non-acid reflux) was 0.54 (95% CI 0.30-0.99). Conclusions: Oesophageal studies after proton pump inhibitor cessation improve the positive yield for acid reflux-related events but reduce the detection of symptomatic non-acid reflux events.status: publishe
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