共查询到20条相似文献,搜索用时 15 毫秒
1.
Jér?me Rousselet Charles-Edouard Imbert Anissa Dekri Jacques Garcia Francis Goussard Bruno Vincent Olivier Denux Christelle Robinet Franck Dorkeld Alain Roques Jean-Pierre Rossi 《PloS one》2013,8(10)
Mapping species spatial distribution using spatial inference and prediction requires a lot of data. Occurrence data are generally not easily available from the literature and are very time-consuming to collect in the field. For that reason, we designed a survey to explore to which extent large-scale databases such as Google maps and Google street view could be used to derive valid occurrence data. We worked with the Pine Processionary Moth (PPM) Thaumetopoea pityocampa because the larvae of that moth build silk nests that are easily visible. The presence of the species at one location can therefore be inferred from visual records derived from the panoramic views available from Google street view. We designed a standardized procedure allowing evaluating the presence of the PPM on a sampling grid covering the landscape under study. The outputs were compared to field data. We investigated two landscapes using grids of different extent and mesh size. Data derived from Google street view were highly similar to field data in the large-scale analysis based on a square grid with a mesh of 16 km (96% of matching records). Using a 2 km mesh size led to a strong divergence between field and Google-derived data (46% of matching records). We conclude that Google database might provide useful occurrence data for mapping the distribution of species which presence can be visually evaluated such as the PPM. However, the accuracy of the output strongly depends on the spatial scales considered and on the sampling grid used. Other factors such as the coverage of Google street view network with regards to sampling grid size and the spatial distribution of host trees with regards to road network may also be determinant. 相似文献
2.
Rolf Wipfli Victor Dubois-Ferrière Sylvain Budry Pierre Hoffmeyer Christian Lovis 《PloS one》2016,11(4)
ObjectiveIn this work, we aim at comparing formally three different interaction modes for image manipulation that are usable in a surgery setting: 1) A gesture-controlled approach using Kinect ®; 2) oral instructions to a third part dedicated to manipulate the images; and 3) direct manipulation using a mouse.Results30 physicians and senior medical students participated in the experiment. Efficiency, measured as time used to pass the scenario, was best when using the mouse (M = 109.10s, SD = 25.96), followed by gesture-controlled (M = 214.97s, SD = 46.29) and oral instructions (M = 246.33s, SD = 76.50). Satisfaction, measured by a questionnaire, was rated highest in the condition mouse (M = 6.63, SD = 0.56), followed by gesture-controlled (M = 5.77, SD = 0.93) and oral instructions (M = 4.40, SD = 1.71). Differences in efficiency and satisfaction rating were significant. No significant difference in effectiveness, measured with error rates, was found.DiscussionThe study shows with formal evaluation that the use of gestures is advantageous over instructions to a third person. In particular, the use of gestures is more efficient than verbalizing instructions. The given gestures could be learned easily and reliability of the tested gesture-control system is good.ConclusionUnder the premise that mouse cannot be used directly during surgery, gesture-controlled approaches demonstrate to be superior to oral instructions for image manipulation. 相似文献
3.
Adam G. Tsai Thomas A. Wadden Marisa A. Rogers Susan C. Day Renee H. Moore Buneka J. Islam 《Obesity (Silver Spring, Md.)》2010,18(8):1614-1618
Most primary care providers (PCPs), constrained by time and resources, cannot provide intensive behavioral counseling for obesity. This study evaluated the effect of using medical assistants (MAs) as weight loss counselors. The study was a randomized controlled trial conducted in two primary care offices at an academic medical center. Patients (n = 50) had a BMI of 27–50 kg/m2 and no contraindications to weight loss. They were randomized to quarterly PCP visits and weight loss materials (Control group) or to the same approach combined with eight visits with a MA over 6 months (Brief Counseling). Outcomes included change in weight and cardiovascular risk factors (glucose, lipids, blood pressure, and waist circumference). Patients in the Brief Counseling and Control groups lost 4.4 ± 0.6 kg (5.1 ± 0.7% of initial weight) and 0.9 ± 0.6 kg (1.0 ± 0.7%), respectively, at month 6 (P < 0.001). There were no significant differences between groups for changes in cardiovascular risk factors. Brief Counseling patients regained weight between month 6 and month 12, when MA visits were discontinued. Attrition was 10% after 6 months and 6% after 12 months. Brief Counseling by MAs induced significant weight loss during 6 months. Office‐based obesity treatment should be tested in larger trials and should include weight loss maintenance counseling. 相似文献
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5.
《Bioscience, biotechnology, and biochemistry》2013,77(11):1940-1941
An improved synthesis of BPA was achieved by a four-step sequence starting from p-formylbenzenebroronic acid (1) and ethyl isocyanoacetate via an ethyl α-formylaminocinnamate derivative (3) in a good overall yield. 相似文献
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Donald R. Olson Kevin J. Konty Marc Paladini Cecile Viboud Lone Simonsen 《PLoS computational biology》2013,9(10)
The goal of influenza-like illness (ILI) surveillance is to determine the timing, location and magnitude of outbreaks by monitoring the frequency and progression of clinical case incidence. Advances in computational and information technology have allowed for automated collection of higher volumes of electronic data and more timely analyses than previously possible. Novel surveillance systems, including those based on internet search query data like Google Flu Trends (GFT), are being used as surrogates for clinically-based reporting of influenza-like-illness (ILI). We investigated the reliability of GFT during the last decade (2003 to 2013), and compared weekly public health surveillance with search query data to characterize the timing and intensity of seasonal and pandemic influenza at the national (United States), regional (Mid-Atlantic) and local (New York City) levels. We identified substantial flaws in the original and updated GFT models at all three geographic scales, including completely missing the first wave of the 2009 influenza A/H1N1 pandemic, and greatly overestimating the intensity of the A/H3N2 epidemic during the 2012/2013 season. These results were obtained for both the original (2008) and the updated (2009) GFT algorithms. The performance of both models was problematic, perhaps because of changes in internet search behavior and differences in the seasonality, geographical heterogeneity and age-distribution of the epidemics between the periods of GFT model-fitting and prospective use. We conclude that GFT data may not provide reliable surveillance for seasonal or pandemic influenza and should be interpreted with caution until the algorithm can be improved and evaluated. Current internet search query data are no substitute for timely local clinical and laboratory surveillance, or national surveillance based on local data collection. New generation surveillance systems such as GFT should incorporate the use of near-real time electronic health data and computational methods for continued model-fitting and ongoing evaluation and improvement. 相似文献
8.
Anette Peterson Lena Hanberger Karin ?kesson Mats Bojestig Boel Andersson G?re Ulf Samuelsson 《PloS one》2014,9(5)
Background
Several studies show that good metabolic control is important for children and adolescents with type 1 diabetes. In Sweden, there are large differences in mean haemoglobin A1c (HbA1c) in different hospitals and difficulties implementing national guidelines in everyday practice. This study shows how the participation in an improvement collaborative could facilitate improvements in the quality of care by paediatric diabetes teams. The Swedish paediatric diabetes quality registry, SWEDIABKIDS was used as a tool and resource for feedback and outcome measures.Methods
Twelve teams at paediatric diabetes centres, caring for 30% (2302/7660) of patients in Sweden, participated in an 18-month quality improvement program. Each team defined treatment targets, areas needing improvement, and action plans. The main outcome was the centre patients'' mean HbA1c levels, but other clinical variables and change concepts were also studied. Data from the previous six months were compared with the first six months after starting the program, and the long-term follow up after another eleven months.Results
All centres reduced mean HbA1c during the second and third periods compared with the first. The mean reduction for all was 3·7 mmol/mol (p<0.001), compared with non-participating centres who improved their mean HbA1c with 1·7 mmol/mol during the same period. Many of the participating centres reduced the frequency of severe hypoglycaemia and/or ketoacidosis, and five centres reached their goal of ensuring that all patients had some sort of physical activity at least once weekly. Change concepts were, for example, improved guidelines, appointment planning, informing the patients, improving teamwork and active use of the registry, and health promotion activities.Conclusions
By involving paediatric diabetes teams in a quality improvement collaborative together with access to a quality register, the quality of paediatric diabetes care can improve, thereby contributing to a reduced risk of late complications for children and adolescents with diabetes. 相似文献9.
改良抗体捕获ELISA方法检测流行性出血热特异性IgE,IgA,IgG抗体的初步研究 总被引:4,自引:0,他引:4
张东海 《Virologica Sinica》1993,8(3):207-212
初步报道建立了一种检测流行性出血热(EHF)特异性IgE、IgA、IgG抗体的改良抗体捕获ELISA方法(EacELISA,AacELISA,GacELISA)。该法以抗人IgE、IgA或IgG单克隆抗体作包被抗体;酶标记物系两株组特异性较强的EHF·McAb(A_(35),A_(25-1)株);在实验中采用EHF病毒抗原与酶标记物混合后一次加入,而不是分别依次加入的方式,使操作步骤简化,实验时间缩短,又适当提高了试验敏感性。该法具有简便,特异性高,灵敏度较高(检测EHF·IgE,EHF·IgA>1:100;EHF·IgG>1:2560),重复性较好(CV:EHF·IgE 2.51%,EHF·IgA 11.80%,EHF·IgG 10.85%)等优点。检测39份EHF病人血清,急性期病人(3~7病日)血清三种抗体的检出率分别为84.21%(16/19,EHF·IgG),89.47%(17/19,EHF·IgA)和100%(19/19,EHF·IgG);而发病3~6月后患者血清三种抗体检出率分别为10.00%(2/20),45.00%(9/20)和100.00%。在急性期与恢复期病人之间,EHF·IgE和EHF·IgA两种抗体的检出率差异较显著(P<0.01)。70价其他人群血清三种抗体检出率均为阴性。 相似文献
10.
Interplay between Telecommunications and Face-to-Face Interactions: A Study Using Mobile Phone Data 总被引:1,自引:0,他引:1
In this study we analyze one year of anonymized telecommunications data for over one million customers from a large European cellphone operator, and we investigate the relationship between people''s calls and their physical location. We discover that more than 90% of users who have called each other have also shared the same space (cell tower), even if they live far apart. Moreover, we find that close to 70% of users who call each other frequently (at least once per month on average) have shared the same space at the same time - an instance that we call co-location. Co-locations appear indicative of coordination calls, which occur just before face-to-face meetings. Their number is highly predictable based on the amount of calls between two users and the distance between their home locations - suggesting a new way to quantify the interplay between telecommunications and face-to-face interactions. 相似文献
11.
Oliver S. Grosser Dennis Kupitz Juri Ruf Damian Czuczwara Ingo G. Steffen Christian Furth Markus Thormann David Loewenthal Jens Ricke Holger Amthauer 《PloS one》2015,10(9)
Background
Hybrid imaging combines nuclear medicine imaging such as single photon emission computed tomography (SPECT) or positron emission tomography (PET) with computed tomography (CT). Through this hybrid design, scanned patients accumulate radiation exposure from both applications. Imaging modalities have been the subject of long-term optimization efforts, focusing on diagnostic applications. It was the aim of this study to investigate the influence of an iterative CT image reconstruction algorithm (ASIR) on the image quality of the low-dose CT images.Methodology/Principal Findings
Examinations were performed with a SPECT-CT scanner with standardized CT and SPECT-phantom geometries and CT protocols with systematically reduced X-ray tube currents. Analyses included image quality with respect to photon flux. Results were compared to the standard FBP reconstructed images. The general impact of the CT-based attenuation maps used during SPECT reconstruction was examined for two SPECT phantoms. Using ASIR for image reconstructions, image noise was reduced compared to FBP reconstructions for the same X-ray tube current. The Hounsfield unit (HU) values reconstructed by ASIR were correlated to the FBP HU values(R2 ≥ 0.88) and the contrast-to-noise ratio (CNR) was improved by ASIR. However, for a phantom with increased attenuation, the HU values shifted for low X-ray tube currents I ≤ 60 mA (p ≤ 0.04). In addition, the shift of the HU values was observed within the attenuation corrected SPECT images for very low X-ray tube currents (I ≤ 20 mA, p ≤ 0.001).Conclusion/Significance
In general, the decrease in X-ray tube current up to 30 mA in combination with ASIR led to a reduction of CT-related radiation exposure without a significant decrease in image quality. 相似文献12.
Sport-related mild traumatic brain injury (mTBI) or concussion is a significant health concern to athletes with potential long-term consequences. The diagnosis of sport concussion and return to sport decision making is one of the greatest challenges facing health care clinicians working in sports. Blood biomarkers have recently demonstrated their potential in assisting the detection of brain injury particularly, in those cases with no obvious physical injury. We have recently discovered plasma soluble cellular prion protein (PrPC) as a potential reliable biomarker for blast induced TBI (bTBI) in a rodent animal model. In order to explore the application of this novel TBI biomarker to sport-related concussion, we conducted a pilot study at the University of Saskatchewan (U of S) by recruiting athlete and non-athlete 18 to 30 year-old students. Using a modified quantitative ELISA method, we first established normal values for the plasma soluble PrPC in male and female students. The measured plasma soluble PrPC in confirmed concussion cases demonstrated a significant elevation of this analyte in post-concussion samples. Data collected from our pilot study indicates that the plasma soluble PrPC is a potential biomarker for sport-related concussion, which may be further developed into a clinical diagnostic tool to assist clinicians in the assessment of sport concussion and return-to-play decision making. 相似文献
13.
George Bouras Elaine Marie Burns Ann-Marie Howell Alex Bottle Thanos Athanasiou Ara Darzi 《PloS one》2015,10(12)
Background
Trends towards day case surgery and enhanced recovery mean that postoperative venous thromboembolism (VTE) may increasingly arise after hospital discharge. However, hospital data alone are unable to capture adverse events that occur outside of the hospital setting. The National Institute for Health and Care Excellence has suggested the use of primary care data to quantify hospital care-related VTE. Data in surgical patients using these resources is lacking. The aim of this study was to measure VTE risk and associated mortality in general surgery using linked primary care and hospital databases, to improve our understanding of harm from VTE that arises beyond hospital stay.Methods
This was a longitudinal cohort study using nationally linked primary care (Clinical Practice Research Datalink, CPRD), hospital administrative (Hospital Episodes Statistics, HES), population statistics (Office of National Statistics, ONS) and National Cancer Intelligence Network databases. Routinely collected information was used to quantify 90-day in-hospital VTE, 90-day post-discharge VTE and 90-day mortality in adults undergoing one of twelve general surgical procedures between 1st April 1997 and 31st March 2012. The earliest postoperative recording of deep vein thrombosis or pulmonary embolism in CPRD, HES and ONS was counted in each patient. Covariates from multiple datasets were combined to derive detailed prediction models for VTE and mortality. Limitation included the capture of VTE presenting to healthcare only and the lack of information on adherence to pharmacological thromboprophylaxis as there was no data linkage to hospital pharmacy records.Results
There were 981 VTE events captured within 90 days of surgery in 168005 procedures (23.7/1000 patient-years). Overall, primary care data increased the detection of postoperative VTE by a factor of 1.38 (981/710) when compared with using HES and ONS only. Total VTE rates ranged between 3.2/1000 patient-years in haemorrhoidectomy to 118.3/1000 patient-years in esophagogastric resection. Predictors of VTE included emergency surgery (OR = 1.91 95%CI 1.60–2.28, p<0.001), age (OR = 1.02 95%CI 1.02–1.03, p<0.001), body mass index (OR = 1.03 95%CI 1.01–1.04, p<0.001), previous VTE (OR = 8.07 95%CI 6.61–9.83, p<0.001), length of stay (OR = 1.00 95%CI 1.00–1.00, p = 0.007) and cancer stages II (OR = 1.38 95%CI 1.03–1.87, p = 0.033), III (OR = 1.50 95%CI 1.11–2.01, p = 0.008) and IV (OR = 1.63 95%CI 1.03–2.59, p = 0.038). Major organ resections had the greatest odds of VTE when adjusted for other risk factors including length of hospital stay. Post-discharge VTE accounted for 64.8% (636/981) of all recorded VTE. In-hospital VTE (165.4/1000 patient-years) was recorded more frequently than post-discharge VTE (16.2/1000 patient-years). Both in-hospital (OR = 2.07 95%CI 1.51–2.85, p<0.001) and post-discharge (OR = 4.03 95%CI 2.95–5.51, p<0.001) VTE independently predicted 90-day mortality. In patients who died and VTE was recorded on HES or CPRD (n = 56), VTE was one of the causes of death in 37.5% (21/56) of cases.Conclusions
A large proportion of postoperative VTE was detected in primary care. Evaluation of linked databases was a useful way of measuring postoperative VTE at population level. These resources identified a significant association between post-discharge VTE and mortality in general surgery. 相似文献14.
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《IRBM》2019,40(3):145-156
ObjectiveElectrocardiogram (ECG) is a diagnostic tool for recording electrical activities of the human heart non-invasively. It is detected by electrodes placed on the surface of the skin in a conductive medium. In medical applications, ECG is used by cardiologists to observe heart anomalies (cardiovascular diseases) such as abnormal heart rhythms, heart attacks, effects of drug dosage on subject's heart and knowledge of previous heart attacks. Recorded ECG signal is generally corrupted by various types of noise/distortion such as cardiac (isoelectric interval, prolonged depolarization and atrial flutter) or extra cardiac (respiration, changes in electrode position, muscle contraction and power line noise). These factors hide the useful information and alter the signal characteristic due to low Signal-to-Noise Ratio (SNR). In such situations, any failure to judge the ECG signal correctly may result in a delay in the treatment and harm a subject (patient) health. Therefore, appropriate pre-processing technique is necessary to improve SNR to facilitate better treatment to the subject. Effects of different pre-processing techniques on ECG signal analysis (based on R-peaks detection) are compared using various Figures of Merit (FoM) such as sensitivity (Se), accuracy (Acc) and detection error rate (DER) along with SNR.MethodsIn this research article, a new fractional wavelet transform (FrWT) has been proposed as a pre-processing technique in order to overcome the disadvantages of other existing commonly used techniques viz. wavelet transform (WT) and the fractional Fourier transform (FrFT). The proposed FrWT technique possesses the properties of multiresolution analysis and represents signal in the fractional domain which consists of representation in terms of rotation of signals in the time–frequency plane. In the literature, ECG signal analysis has been improvised using statistical pre-processing techniques such as principal component analysis (PCA), and independent component analysis (ICA). However, both PCA and ICA are prone to suffer from slight alterations in either signal or noise, unless the basis functions are prepared with a worldwide set of ECG. Independent Principal Component Analysis (IPCA) has been used to overcome this shortcoming of PCA and ICA. Therefore, in this paper three techniques viz. FrFT, FrWT and IPCA are selected for comparison in pre-processing of ECG signals.ResultsThe selected methods have been evaluated on the basis of SNR, Se, Acc and DER of the detected ECG beats. FrWT yields the best results among all the methods considered in this paper; 34.37dB output SNR, 99.98% Se, 99.96% Acc, and 0.036% DER. These results indicate the quality of biology-related information retained from the pre-processed ECG signals for identifying different heart abnormalities.ConclusionCorrect analysis of the acquired ECG signal is the main challenge for cardiologist due to involvement of various types of noises (high and low frequency). Twenty two real time ECG records have been evaluated based on various FoM such as SNR, Se, Acc and DER for the proposed FrWT and existing FrFT and IPCA preprocessing techniques. Acquired real-time ECG database in normal and disease situations is used for the purpose. The values of FoMs indicate high SNR and better detection of R-peaks in a ECG signal which is important for the diagnosis of cardiovascular disease. The proposed FrWT outperforms all other techniques and holds both analytical attributes of the actual ECG signal and alterations in the amplitudes of various ECG waveforms adequately. It also provides signal portrayals in the time-fractional-frequency plane with low computational complexity enabling their use practically for versatile applications. 相似文献
16.
Chomba Sinyangwe Kirstie Graham Sarala Nicholas Rebecca King Samuel Mukupa Karin K?llander Helen Counihan Mark Montague James Tibenderana Prudence Hamade 《PloS one》2016,11(3)
Background
Pneumonia is the leading infectious cause of mortality in children under five worldwide. Community-level interventions, such as integrated community case management, have great potential to reduce the burden of pneumonia, as well as other diseases, especially in remote populations. However, there are still questions as to whether community health workers (CHW) are able to accurately assess symptoms of pneumonia and prescribe appropriate treatment. This research addresses limitations of previous studies using innovative methodology to assess the accuracy of respiratory rate measurement by CHWs and provides new evidence on the quality of care given for children with symptoms of pneumonia. It is one of few that assesses CHW performance in their usual setting, with independent re-examination by experts, following a considerable period of time post-training of CHWs.Methods
In this cross-sectional mixed methods study, 1,497 CHW consultations, conducted by 90 CHWs in two districts of Luapula province, Zambia, were directly observed, with measurement of respiratory rate for children with suspected pneumonia recorded by video. Using the video footage, a retrospective reference standard assessment of respiratory rate was conducted by experts. Counts taken by CHWs were compared against the reference standard and appropriateness of the treatment prescribed by CHWs was assessed. To supplement observational findings, three focus group discussions and nine in depth interviews with CHWs were conducted.Results and Conclusion
The findings support existing literature that CHWs are capable of measuring respiratory rates and providing appropriate treatment, with 81% and 78% agreement, respectively, between CHWs and experts. Accuracy in diagnosis could be strengthened through further training and the development of improved diagnostic tools appropriate for resource-poor settings. 相似文献17.
Oleh Dzyubachyk Artem Khmelinskii Esben Plenge Peter Kok Thomas J. A. Snoeks Dirk H. J. Poot Clemens W. G. M. L?wik Charl P. Botha Wiro J. Niessen Louise van der Weerd Erik Meijering Boudewijn P. F. Lelieveldt 《PloS one》2014,9(9)
In small animal imaging studies, when the locations of the micro-structures of interest are unknown a priori, there is a simultaneous need for full-body coverage and high resolution. In MRI, additional requirements to image contrast and acquisition time will often make it impossible to acquire such images directly. Recently, a resolution enhancing post-processing technique called super-resolution reconstruction (SRR) has been demonstrated to improve visualization and localization of micro-structures in small animal MRI by combining multiple low-resolution acquisitions. However, when the field-of-view is large relative to the desired voxel size, solving the SRR problem becomes very expensive, in terms of both memory requirements and computation time. In this paper we introduce a novel local approach to SRR that aims to overcome the computational problems and allow researchers to efficiently explore both global and local characteristics in whole-body small animal MRI. The method integrates state-of-the-art image processing techniques from the areas of articulated atlas-based segmentation, planar reformation, and SRR. A proof-of-concept is provided with two case studies involving CT, BLI, and MRI data of bone and kidney tumors in a mouse model. We show that local SRR-MRI is a computationally efficient complementary imaging modality for the precise characterization of tumor metastases, and that the method provides a feasible high-resolution alternative to conventional MRI. 相似文献
18.
Background
Recent linkage between primary and secondary care data has provided valuable information for studying heath outcomes that may initially present in different health care settings. The aim of this study was therefore, twofold: to use linked primary and secondary care data to determine an optimum definition for estimating the incidence of first VTE in and around pregnancy; and secondly to conduct a systematic literature review of studies on perinatal VTE incidence with the purpose of comparing our estimates.Methods
We used primary care data from the Clinical Practice Research Datalink (CPRD), which incorporates linkages to secondary care contained within Hospital Episode Statistics (HES) between 1997 and 2010 to estimate the incidence rate of VTE in the antepartum and postpartum period. We systematically searched the literature on the incidence of VTE during antepartum and postpartum periods and performed a meta-analysis to provide comparison.Findings
Using combined CPRD and HES data and a restrictive VTE definition, the absolute rate during the antepartum period and first six weeks postpartum (early postpartum) were 99 (95%CI 85–116) and 468 (95%CI 391–561) per 100,000 person-years respectively. These were comparable to the pooled estimates from our meta-analysis (using studies after 2005) during the antepartum period (118/100,000 person-years) and early postpartum (424/100,000 person-years). When we used only secondary care data to identify VTE events, incidence was lower during the early postpartum period (308/100,000 person-years), whereas relying only on primary care data lead to lower incidence during the time around delivery, but higher rates during the postpartum period (558/100,000 person-years).Conclusion
Using combined CPRD and HES data gives estimates of the risk of VTE in and around pregnancy that are comparable to the existing literature. It also provides more accurate estimation of the date of VTE diagnosis which will allow risk stratification during specific pregnancy and postpartum periods. 相似文献19.
20.
Bonnie L. Raphael 《Zoo biology》1995,14(3):289-290