Is STAPLE algorithm confident to assess segmentation methods in PET imaging?
NASA Astrophysics Data System (ADS)
Dewalle-Vignion, Anne-Sophie; Betrouni, Nacim; Baillet, Clio; Vermandel, Maximilien
2015-12-01
Accurate tumor segmentation in [18F]-fluorodeoxyglucose positron emission tomography is crucial for tumor response assessment and target volume definition in radiation therapy. Evaluation of segmentation methods from clinical data without ground truth is usually based on physicians’ manual delineations. In this context, the simultaneous truth and performance level estimation (STAPLE) algorithm could be useful to manage the multi-observers variability. In this paper, we evaluated how this algorithm could accurately estimate the ground truth in PET imaging. Complete evaluation study using different criteria was performed on simulated data. The STAPLE algorithm was applied to manual and automatic segmentation results. A specific configuration of the implementation provided by the Computational Radiology Laboratory was used. Consensus obtained by the STAPLE algorithm from manual delineations appeared to be more accurate than manual delineations themselves (80% of overlap). An improvement of the accuracy was also observed when applying the STAPLE algorithm to automatic segmentations results. The STAPLE algorithm, with the configuration used in this paper, is more appropriate than manual delineations alone or automatic segmentations results alone to estimate the ground truth in PET imaging. Therefore, it might be preferred to assess the accuracy of tumor segmentation methods in PET imaging.
Is STAPLE algorithm confident to assess segmentation methods in PET imaging?
Dewalle-Vignion, Anne-Sophie; Betrouni, Nacim; Baillet, Clio; Vermandel, Maximilien
2015-12-21
Accurate tumor segmentation in [18F]-fluorodeoxyglucose positron emission tomography is crucial for tumor response assessment and target volume definition in radiation therapy. Evaluation of segmentation methods from clinical data without ground truth is usually based on physicians' manual delineations. In this context, the simultaneous truth and performance level estimation (STAPLE) algorithm could be useful to manage the multi-observers variability. In this paper, we evaluated how this algorithm could accurately estimate the ground truth in PET imaging. Complete evaluation study using different criteria was performed on simulated data. The STAPLE algorithm was applied to manual and automatic segmentation results. A specific configuration of the implementation provided by the Computational Radiology Laboratory was used. Consensus obtained by the STAPLE algorithm from manual delineations appeared to be more accurate than manual delineations themselves (80% of overlap). An improvement of the accuracy was also observed when applying the STAPLE algorithm to automatic segmentations results. The STAPLE algorithm, with the configuration used in this paper, is more appropriate than manual delineations alone or automatic segmentations results alone to estimate the ground truth in PET imaging. Therefore, it might be preferred to assess the accuracy of tumor segmentation methods in PET imaging.
Commowick, Olivier; Akhondi-Asl, Alireza; Warfield, Simon K.
2012-01-01
We present a new algorithm, called local MAP STAPLE, to estimate from a set of multi-label segmentations both a reference standard segmentation and spatially varying performance parameters. It is based on a sliding window technique to estimate the segmentation and the segmentation performance parameters for each input segmentation. In order to allow for optimal fusion from the small amount of data in each local region, and to account for the possibility of labels not being observed in a local region of some (or all) input segmentations, we introduce prior probabilities for the local performance parameters through a new Maximum A Posteriori formulation of STAPLE. Further, we propose an expression to compute confidence intervals in the estimated local performance parameters. We carried out several experiments with local MAP STAPLE to characterize its performance and value for local segmentation evaluation. First, with simulated segmentations with known reference standard segmentation and spatially varying performance, we show that local MAP STAPLE performs better than both STAPLE and majority voting. Then we present evaluations with data sets from clinical applications. These experiments demonstrate that spatial adaptivity in segmentation performance is an important property to capture. We compared the local MAP STAPLE segmentations to STAPLE, and to previously published fusion techniques and demonstrate the superiority of local MAP STAPLE over other state-of-the- art algorithms. PMID:22562727
Statistical fusion of continuous labels: identification of cardiac landmarks
NASA Astrophysics Data System (ADS)
Xing, Fangxu; Soleimanifard, Sahar; Prince, Jerry L.; Landman, Bennett A.
2011-03-01
Image labeling is an essential task for evaluating and analyzing morphometric features in medical imaging data. Labels can be obtained by either human interaction or automated segmentation algorithms. However, both approaches for labeling suffer from inevitable error due to noise and artifact in the acquired data. The Simultaneous Truth And Performance Level Estimation (STAPLE) algorithm was developed to combine multiple rater decisions and simultaneously estimate unobserved true labels as well as each rater's level of performance (i.e., reliability). A generalization of STAPLE for the case of continuous-valued labels has also been proposed. In this paper, we first show that with the proposed Gaussian distribution assumption, this continuous STAPLE formulation yields equivalent likelihoods for the bias parameter, meaning that the bias parameter-one of the key performance indices-is actually indeterminate. We resolve this ambiguity by augmenting the STAPLE expectation maximization formulation to include a priori probabilities on the performance level parameters, which enables simultaneous, meaningful estimation of both the rater bias and variance performance measures. We evaluate and demonstrate the efficacy of this approach in simulations and also through a human rater experiment involving the identification the intersection points of the right ventricle to the left ventricle in CINE cardiac data.
Statistical Fusion of Continuous Labels: Identification of Cardiac Landmarks.
Xing, Fangxu; Soleimanifard, Sahar; Prince, Jerry L; Landman, Bennett A
2011-01-01
Image labeling is an essential task for evaluating and analyzing morphometric features in medical imaging data. Labels can be obtained by either human interaction or automated segmentation algorithms. However, both approaches for labeling suffer from inevitable error due to noise and artifact in the acquired data. The Simultaneous Truth And Performance Level Estimation (STAPLE) algorithm was developed to combine multiple rater decisions and simultaneously estimate unobserved true labels as well as each rater's level of performance (i.e., reliability). A generalization of STAPLE for the case of continuous-valued labels has also been proposed. In this paper, we first show that with the proposed Gaussian distribution assumption, this continuous STAPLE formulation yields equivalent likelihoods for the bias parameter, meaning that the bias parameter-one of the key performance indices-is actually indeterminate. We resolve this ambiguity by augmenting the STAPLE expectation maximization formulation to include a priori probabilities on the performance level parameters, which enables simultaneous, meaningful estimation of both the rater bias and variance performance measures. We evaluate and demonstrate the efficacy of this approach in simulations and also through a human rater experiment involving the identification the intersection points of the right ventricle to the left ventricle in CINE cardiac data.
Commowick, Olivier; Warfield, Simon K
2010-01-01
In order to evaluate the quality of segmentations of an image and assess intra- and inter-expert variability in segmentation performance, an Expectation Maximization (EM) algorithm for Simultaneous Truth And Performance Level Estimation (STAPLE) was recently developed. This algorithm, originally presented for segmentation validation, has since been used for many applications, such as atlas construction and decision fusion. However, the manual delineation of structures of interest is a very time consuming and burdensome task. Further, as the time required and burden of manual delineation increase, the accuracy of the delineation is decreased. Therefore, it may be desirable to ask the experts to delineate only a reduced number of structures or the segmentation of all structures by all experts may simply not be achieved. Fusion from data with some structures not segmented by each expert should be carried out in a manner that accounts for the missing information. In other applications, locally inconsistent segmentations may drive the STAPLE algorithm into an undesirable local optimum, leading to misclassifications or misleading experts performance parameters. We present a new algorithm that allows fusion with partial delineation and which can avoid convergence to undesirable local optima in the presence of strongly inconsistent segmentations. The algorithm extends STAPLE by incorporating prior probabilities for the expert performance parameters. This is achieved through a Maximum A Posteriori formulation, where the prior probabilities for the performance parameters are modeled by a beta distribution. We demonstrate that this new algorithm enables dramatically improved fusion from data with partial delineation by each expert in comparison to fusion with STAPLE. PMID:20879379
Commowick, Olivier; Warfield, Simon K
2010-01-01
In order to evaluate the quality of segmentations of an image and assess intra- and inter-expert variability in segmentation performance, an Expectation Maximization (EM) algorithm for Simultaneous Truth And Performance Level Estimation (STAPLE) was recently developed. This algorithm, originally presented for segmentation validation, has since been used for many applications, such as atlas construction and decision fusion. However, the manual delineation of structures of interest is a very time consuming and burdensome task. Further, as the time required and burden of manual delineation increase, the accuracy of the delineation is decreased. Therefore, it may be desirable to ask the experts to delineate only a reduced number of structures or the segmentation of all structures by all experts may simply not be achieved. Fusion from data with some structures not segmented by each expert should be carried out in a manner that accounts for the missing information. In other applications, locally inconsistent segmentations may drive the STAPLE algorithm into an undesirable local optimum, leading to misclassifications or misleading experts performance parameters. We present a new algorithm that allows fusion with partial delineation and which can avoid convergence to undesirable local optima in the presence of strongly inconsistent segmentations. The algorithm extends STAPLE by incorporating prior probabilities for the expert performance parameters. This is achieved through a Maximum A Posteriori formulation, where the prior probabilities for the performance parameters are modeled by a beta distribution. We demonstrate that this new algorithm enables dramatically improved fusion from data with partial delineation by each expert in comparison to fusion with STAPLE.
Lebenberg, Jessica; Lalande, Alain; Clarysse, Patrick; Buvat, Irene; Casta, Christopher; Cochet, Alexandre; Constantinidès, Constantin; Cousty, Jean; de Cesare, Alain; Jehan-Besson, Stephanie; Lefort, Muriel; Najman, Laurent; Roullot, Elodie; Sarry, Laurent; Tilmant, Christophe; Frouin, Frederique; Garreau, Mireille
2015-01-01
This work aimed at combining different segmentation approaches to produce a robust and accurate segmentation result. Three to five segmentation results of the left ventricle were combined using the STAPLE algorithm and the reliability of the resulting segmentation was evaluated in comparison with the result of each individual segmentation method. This comparison was performed using a supervised approach based on a reference method. Then, we used an unsupervised statistical evaluation, the extended Regression Without Truth (eRWT) that ranks different methods according to their accuracy in estimating a specific biomarker in a population. The segmentation accuracy was evaluated by estimating six cardiac function parameters resulting from the left ventricle contour delineation using a public cardiac cine MRI database. Eight different segmentation methods, including three expert delineations and five automated methods, were considered, and sixteen combinations of the automated methods using STAPLE were investigated. The supervised and unsupervised evaluations demonstrated that in most cases, STAPLE results provided better estimates than individual automated segmentation methods. Overall, combining different automated segmentation methods improved the reliability of the segmentation result compared to that obtained using an individual method and could achieve the accuracy of an expert.
Lebenberg, Jessica; Lalande, Alain; Clarysse, Patrick; Buvat, Irene; Casta, Christopher; Cochet, Alexandre; Constantinidès, Constantin; Cousty, Jean; de Cesare, Alain; Jehan-Besson, Stephanie; Lefort, Muriel; Najman, Laurent; Roullot, Elodie; Sarry, Laurent; Tilmant, Christophe
2015-01-01
This work aimed at combining different segmentation approaches to produce a robust and accurate segmentation result. Three to five segmentation results of the left ventricle were combined using the STAPLE algorithm and the reliability of the resulting segmentation was evaluated in comparison with the result of each individual segmentation method. This comparison was performed using a supervised approach based on a reference method. Then, we used an unsupervised statistical evaluation, the extended Regression Without Truth (eRWT) that ranks different methods according to their accuracy in estimating a specific biomarker in a population. The segmentation accuracy was evaluated by estimating six cardiac function parameters resulting from the left ventricle contour delineation using a public cardiac cine MRI database. Eight different segmentation methods, including three expert delineations and five automated methods, were considered, and sixteen combinations of the automated methods using STAPLE were investigated. The supervised and unsupervised evaluations demonstrated that in most cases, STAPLE results provided better estimates than individual automated segmentation methods. Overall, combining different automated segmentation methods improved the reliability of the segmentation result compared to that obtained using an individual method and could achieve the accuracy of an expert. PMID:26287691
Automatic Structural Parcellation of Mouse Brain MRI Using Multi-Atlas Label Fusion
Ma, Da; Cardoso, Manuel J.; Modat, Marc; Powell, Nick; Wells, Jack; Holmes, Holly; Wiseman, Frances; Tybulewicz, Victor; Fisher, Elizabeth; Lythgoe, Mark F.; Ourselin, Sébastien
2014-01-01
Multi-atlas segmentation propagation has evolved quickly in recent years, becoming a state-of-the-art methodology for automatic parcellation of structural images. However, few studies have applied these methods to preclinical research. In this study, we present a fully automatic framework for mouse brain MRI structural parcellation using multi-atlas segmentation propagation. The framework adopts the similarity and truth estimation for propagated segmentations (STEPS) algorithm, which utilises a locally normalised cross correlation similarity metric for atlas selection and an extended simultaneous truth and performance level estimation (STAPLE) framework for multi-label fusion. The segmentation accuracy of the multi-atlas framework was evaluated using publicly available mouse brain atlas databases with pre-segmented manually labelled anatomical structures as the gold standard, and optimised parameters were obtained for the STEPS algorithm in the label fusion to achieve the best segmentation accuracy. We showed that our multi-atlas framework resulted in significantly higher segmentation accuracy compared to single-atlas based segmentation, as well as to the original STAPLE framework. PMID:24475148
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hoang Duc, Albert K., E-mail: albert.hoangduc.ucl@gmail.com; McClelland, Jamie; Modat, Marc
Purpose: The aim of this study was to assess whether clinically acceptable segmentations of organs at risk (OARs) in head and neck cancer can be obtained automatically and efficiently using the novel “similarity and truth estimation for propagated segmentations” (STEPS) compared to the traditional “simultaneous truth and performance level estimation” (STAPLE) algorithm. Methods: First, 6 OARs were contoured by 2 radiation oncologists in a dataset of 100 patients with head and neck cancer on planning computed tomography images. Each image in the dataset was then automatically segmented with STAPLE and STEPS using those manual contours. Dice similarity coefficient (DSC) wasmore » then used to compare the accuracy of these automatic methods. Second, in a blind experiment, three separate and distinct trained physicians graded manual and automatic segmentations into one of the following three grades: clinically acceptable as determined by universal delineation guidelines (grade A), reasonably acceptable for clinical practice upon manual editing (grade B), and not acceptable (grade C). Finally, STEPS segmentations graded B were selected and one of the physicians manually edited them to grade A. Editing time was recorded. Results: Significant improvements in DSC can be seen when using the STEPS algorithm on large structures such as the brainstem, spinal canal, and left/right parotid compared to the STAPLE algorithm (all p < 0.001). In addition, across all three trained physicians, manual and STEPS segmentation grades were not significantly different for the brainstem, spinal canal, parotid (right/left), and optic chiasm (all p > 0.100). In contrast, STEPS segmentation grades were lower for the eyes (p < 0.001). Across all OARs and all physicians, STEPS produced segmentations graded as well as manual contouring at a rate of 83%, giving a lower bound on this rate of 80% with 95% confidence. Reduction in manual interaction time was on average 61% and 93% when automatic segmentations did and did not, respectively, require manual editing. Conclusions: The STEPS algorithm showed better performance than the STAPLE algorithm in segmenting OARs for radiotherapy of the head and neck. It can automatically produce clinically acceptable segmentation of OARs, with results as relevant as manual contouring for the brainstem, spinal canal, the parotids (left/right), and optic chiasm. A substantial reduction in manual labor was achieved when using STEPS even when manual editing was necessary.« less
NASA Astrophysics Data System (ADS)
Martin, Spencer; Brophy, Mark; Palma, David; Louie, Alexander V.; Yu, Edward; Yaremko, Brian; Ahmad, Belal; Barron, John L.; Beauchemin, Steven S.; Rodrigues, George; Gaede, Stewart
2015-02-01
This work aims to propose and validate a framework for tumour volume auto-segmentation based on ground-truth estimates derived from multi-physician input contours to expedite 4D-CT based lung tumour volume delineation. 4D-CT datasets of ten non-small cell lung cancer (NSCLC) patients were manually segmented by 6 physicians. Multi-expert ground truth (GT) estimates were constructed using the STAPLE algorithm for the gross tumour volume (GTV) on all respiratory phases. Next, using a deformable model-based method, multi-expert GT on each individual phase of the 4D-CT dataset was propagated to all other phases providing auto-segmented GTVs and motion encompassing internal gross target volumes (IGTVs) based on GT estimates (STAPLE) from each respiratory phase of the 4D-CT dataset. Accuracy assessment of auto-segmentation employed graph cuts for 3D-shape reconstruction and point-set registration-based analysis yielding volumetric and distance-based measures. STAPLE-based auto-segmented GTV accuracy ranged from (81.51 ± 1.92) to (97.27 ± 0.28)% volumetric overlap of the estimated ground truth. IGTV auto-segmentation showed significantly improved accuracies with reduced variance for all patients ranging from 90.87 to 98.57% volumetric overlap of the ground truth volume. Additional metrics supported these observations with statistical significance. Accuracy of auto-segmentation was shown to be largely independent of selection of the initial propagation phase. IGTV construction based on auto-segmented GTVs within the 4D-CT dataset provided accurate and reliable target volumes compared to manual segmentation-based GT estimates. While inter-/intra-observer effects were largely mitigated, the proposed segmentation workflow is more complex than that of current clinical practice and requires further development.
Martin, Spencer; Brophy, Mark; Palma, David; Louie, Alexander V; Yu, Edward; Yaremko, Brian; Ahmad, Belal; Barron, John L; Beauchemin, Steven S; Rodrigues, George; Gaede, Stewart
2015-02-21
This work aims to propose and validate a framework for tumour volume auto-segmentation based on ground-truth estimates derived from multi-physician input contours to expedite 4D-CT based lung tumour volume delineation. 4D-CT datasets of ten non-small cell lung cancer (NSCLC) patients were manually segmented by 6 physicians. Multi-expert ground truth (GT) estimates were constructed using the STAPLE algorithm for the gross tumour volume (GTV) on all respiratory phases. Next, using a deformable model-based method, multi-expert GT on each individual phase of the 4D-CT dataset was propagated to all other phases providing auto-segmented GTVs and motion encompassing internal gross target volumes (IGTVs) based on GT estimates (STAPLE) from each respiratory phase of the 4D-CT dataset. Accuracy assessment of auto-segmentation employed graph cuts for 3D-shape reconstruction and point-set registration-based analysis yielding volumetric and distance-based measures. STAPLE-based auto-segmented GTV accuracy ranged from (81.51 ± 1.92) to (97.27 ± 0.28)% volumetric overlap of the estimated ground truth. IGTV auto-segmentation showed significantly improved accuracies with reduced variance for all patients ranging from 90.87 to 98.57% volumetric overlap of the ground truth volume. Additional metrics supported these observations with statistical significance. Accuracy of auto-segmentation was shown to be largely independent of selection of the initial propagation phase. IGTV construction based on auto-segmented GTVs within the 4D-CT dataset provided accurate and reliable target volumes compared to manual segmentation-based GT estimates. While inter-/intra-observer effects were largely mitigated, the proposed segmentation workflow is more complex than that of current clinical practice and requires further development.
Balancing the Role of Priors in Multi-Observer Segmentation Evaluation
Huang, Xiaolei; Wang, Wei; Lopresti, Daniel; Long, Rodney; Antani, Sameer; Xue, Zhiyun; Thoma, George
2009-01-01
Comparison of a group of multiple observer segmentations is known to be a challenging problem. A good segmentation evaluation method would allow different segmentations not only to be compared, but to be combined to generate a “true” segmentation with higher consensus. Numerous multi-observer segmentation evaluation approaches have been proposed in the literature, and STAPLE in particular probabilistically estimates the true segmentation by optimal combination of observed segmentations and a prior model of the truth. An Expectation–Maximization (EM) algorithm, STAPLE’S convergence to the desired local minima depends on good initializations for the truth prior and the observer-performance prior. However, accurate modeling of the initial truth prior is nontrivial. Moreover, among the two priors, the truth prior always dominates so that in certain scenarios when meaningful observer-performance priors are available, STAPLE can not take advantage of that information. In this paper, we propose a Bayesian decision formulation of the problem that permits the two types of prior knowledge to be integrated in a complementary manner in four cases with differing application purposes: (1) with known truth prior; (2) with observer prior; (3) with neither truth prior nor observer prior; and (4) with both truth prior and observer prior. The third and fourth cases are not discussed (or effectively ignored) by STAPLE, and in our research we propose a new method to combine multiple-observer segmentations based on the maximum a posterior (MAP) principle, which respects the observer prior regardless of the availability of the truth prior. Based on the four scenarios, we have developed a web-based software application that implements the flexible segmentation evaluation framework for digitized uterine cervix images. Experiment results show that our framework has flexibility in effectively integrating different priors for multi-observer segmentation evaluation and it also generates results comparing favorably to those by the STAPLE algorithm and the Majority Vote Rule. PMID:20523759
Local SIMPLE multi-atlas-based segmentation applied to lung lobe detection on chest CT
NASA Astrophysics Data System (ADS)
Agarwal, M.; Hendriks, E. A.; Stoel, B. C.; Bakker, M. E.; Reiber, J. H. C.; Staring, M.
2012-02-01
For multi atlas-based segmentation approaches, a segmentation fusion scheme which considers local performance measures may be more accurate than a method which uses a global performance measure. We improve upon an existing segmentation fusion method called SIMPLE and extend it to be localized and suitable for multi-labeled segmentations. We demonstrate the algorithm performance on 23 CT scans of COPD patients using a leave-one- out experiment. Our algorithm performs significantly better (p < 0.01) than majority voting, STAPLE, and SIMPLE, with a median overlap of the fissure of 0.45, 0.48, 0.55 and 0.6 for majority voting, STAPLE, SIMPLE, and the proposed algorithm, respectively.
Will Transition of Staple Food Strategy in China Really Mitigate Global Climate Change?
NASA Astrophysics Data System (ADS)
Liu, B.; Zhao, D.
2017-12-01
With the increase in agricultural demand, reducing greenhouse gas (GHG) emissions is a vital challenge in mitigating climate change. Potato staple food strategy in China introduced by Ministry of Agriculture in 2015 is to gradually adjust staple food structure, which provides an opportunity to meet with the challenge. Apart from staple food structure, difference on energy, material input, geography, and crop management are essential to determine agriculture's contribution to climate change. In this study, we conduct a life cycle analysis of four staple foods in China, namely rice, wheat, maize, and potato, to develop crop-specific estimates of GHG emissions and GHG intensity by using `Production intensity' (carbon dioxide equivalent emissions per kilocalorie produced), to help us understand potential synergies and frictions between food producing and climate mitigation. Data used in this study is on city / province levels if city level is unavailable in 2015. First, we evaluate GHG reductions due to transition of staple food structure in China. Staple food GHG emissions in China are 546.90 Tg CO2e yr-1 in 2015, with 47.6%, 21.9%, 27.3% and 3.2% from rice, wheat, maize and potato. Mean production intensity of staple food is 0.45 Mg CO2e M kcal-1 in 2015. Maize leads the intensity with 0.77 Mg CO2e M kcal-1, followed by rice (0.49 Mg CO2e M kcal-1), wheat (0.28 Mg CO2e M kcal-1) and potato (0.24 Mg CO2e M kcal-1). After staple food structure adjustment, 25 Tg CO2e yr-1 (4.2%) reduction will be accomplished in 2020 without any crop management improvement. Further reduction (33.3% - 40.4%) could be achieved with crop management improvement. In addition, because of staple food structure switching, native rice production will decline, which might lead to more export from countries with higher production intensity. Estimated emission leakage from rice import is 30.10 Tg CO2e yr-1, exceeds emission reduction in native China. Therefore, potato staple food strategy could meet the demand for food in China, but it increases risk of global climate change.
Formulating Spatially Varying Performance in the Statistical Fusion Framework
Landman, Bennett A.
2012-01-01
To date, label fusion methods have primarily relied either on global (e.g. STAPLE, globally weighted vote) or voxelwise (e.g. locally weighted vote) performance models. Optimality of the statistical fusion framework hinges upon the validity of the stochastic model of how a rater errs (i.e., the labeling process model). Hitherto, approaches have tended to focus on the extremes of potential models. Herein, we propose an extension to the STAPLE approach to seamlessly account for spatially varying performance by extending the performance level parameters to account for a smooth, voxelwise performance level field that is unique to each rater. This approach, Spatial STAPLE, provides significant improvements over state-of-the-art label fusion algorithms in both simulated and empirical data sets. PMID:22438513
Joo, Ji Hyeon; Cho, Byung Chul; Jeong, Chi Young; Park, Won; Kim, Hak Jae; Yoon, Won Sup; Yoon, Mee Sun; Kim, Ji-Yoon; Choi, Jin Hwa; Choi, Youngmin; Kim, Joo-Young
2017-01-01
Purpose To determine inter-observer variability in target volume definition of cervical cancer in radical and adjuvant radiotherapy (RT) settings. Methods Eight physicians contoured CTVs of 2 patients underwent definitive and postoperative RT. Each volume was analyzed using the individual/median volume ratio and generalized conformity index (CIgen). And center of mass (COM) of each contour was calculated. Expert agreement was quantified using an expectation maximization algorithm for Simultaneous Truth and Performance Level Estimation (STAPLE). Results For definitive RT, the individual/median volume ratio ranged from 0.51 to 1.41, and CIgen was 0.531. Mean 3-dimensional distances of average to each COM were 7.8 mm. For postoperative RT setting, corresponding values were 0.65–1.38, 0.563, and 5.3 mm. Kappa value of expert agreement was 0.65 and 0.67, respectively. STAPLE estimates of the sensitivity, specificity, and kappa measures of inter-physician agreement were 0.73, 0.98, and 0.65 for the definitive and 0.75, 0.98, and 0.67 for the adjuvant radiotherapy setting. The largest difference was observed in the superior-inferior direction, particularly in the upper vagina and the common iliac area. Conclusion As there was still some variability in target delineation, more detailed guidelines for target volume delineation and continuing education would help to reduce this uncertainty. PMID:28301492
Morris, Alan; Burgon, Nathan; McGann, Christopher; MacLeod, Robert; Cates, Joshua
2013-01-01
Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts. PMID:24236224
NASA Astrophysics Data System (ADS)
Perry, Daniel; Morris, Alan; Burgon, Nathan; McGann, Christopher; MacLeod, Robert; Cates, Joshua
2012-03-01
Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts.
Evaluation of an automatic segmentation algorithm for definition of head and neck organs at risk.
Thomson, David; Boylan, Chris; Liptrot, Tom; Aitkenhead, Adam; Lee, Lip; Yap, Beng; Sykes, Andrew; Rowbottom, Carl; Slevin, Nicholas
2014-08-03
The accurate definition of organs at risk (OARs) is required to fully exploit the benefits of intensity-modulated radiotherapy (IMRT) for head and neck cancer. However, manual delineation is time-consuming and there is considerable inter-observer variability. This is pertinent as function-sparing and adaptive IMRT have increased the number and frequency of delineation of OARs. We evaluated accuracy and potential time-saving of Smart Probabilistic Image Contouring Engine (SPICE) automatic segmentation to define OARs for salivary-, swallowing- and cochlea-sparing IMRT. Five clinicians recorded the time to delineate five organs at risk (parotid glands, submandibular glands, larynx, pharyngeal constrictor muscles and cochleae) for each of 10 CT scans. SPICE was then used to define these structures. The acceptability of SPICE contours was initially determined by visual inspection and the total time to modify them recorded per scan. The Simultaneous Truth and Performance Level Estimation (STAPLE) algorithm created a reference standard from all clinician contours. Clinician, SPICE and modified contours were compared against STAPLE by the Dice similarity coefficient (DSC) and mean/maximum distance to agreement (DTA). For all investigated structures, SPICE contours were less accurate than manual contours. However, for parotid/submandibular glands they were acceptable (median DSC: 0.79/0.80; mean, maximum DTA: 1.5 mm, 14.8 mm/0.6 mm, 5.7 mm). Modified SPICE contours were also less accurate than manual contours. The utilisation of SPICE did not result in time-saving/improve efficiency. Improvements in accuracy of automatic segmentation for head and neck OARs would be worthwhile and are required before its routine clinical implementation.
Sakuma, Hisako; Watanabe, Yasushi; Furusawa, Hiroko; Yoshinari, Tomoya; Akashi, Hajime; Kawakami, Hiroshi; Saito, Shiro; Sugita-Konishi, Yoshiko
2013-01-01
Mycotoxins are commonly present in cereal grains and are not completely destroyed during their cooking and processing. When mycotoxins contaminate staple foods, the risk for exposure becomes serious. In East Asia, including Japan, rice is consumed as a staple food, and with the increasingly Westernized lifestyle, the consumption of wheat has increased. The mycotoxins commonly associated with rice and wheat are total aflatoxin (AFL) and ochratoxin A (OTA), respectively. This study examined the retention of AFL and OTA during the cooking of rice and pasta. AFL was retained at 83%–89% the initial level after the cooking of steamed rice. In pasta noodles, more than 60% of the OTA was retained. These results show that AFL and OTA are relatively stable during the cooking process, suggesting that a major reduction in the exposure to these mycotoxins cannot be expected to occur by cooking rice and pasta. The estimated exposure assessment at the high consumer level (95th percentile) and the mycotoxin contamination level determined by taking into account these reductions in the present study should be useful for the establishment of practical regulations for mycotoxins in staple foods. PMID:23698358
Frequency of Dehiscence in Hand-Sutured and Stapled Intestinal Anastomoses in Dogs.
Duell, Jason R; Thieman Mankin, Kelley M; Rochat, Mark C; Regier, Penny J; Singh, Ameet; Luther, Jill K; Mison, Michael B; Leeman, Jessica J; Budke, Christine M
2016-01-01
To determine the frequency of dehiscence of hand-sutured and stapled intestinal anastomoses in the dog and compare the surgery duration for the methods of anastomosis. Historical cohort study. Two hundred fourteen client-owned dogs undergoing hand-sutured (n = 142) or stapled (n = 72) intestinal anastomoses. Medical records from 5 referral institutions were searched for dogs undergoing intestinal resection and anastomosis between March 2006 and February 2014. Demographic data, presence of septic peritonitis before surgery, surgical technique (hand-sutured or stapled), surgery duration, surgeon (resident versus faculty member), indication for surgical intervention, anatomic location of resection and anastomosis, and if dehiscence was noted postoperatively were retrieved. Estimated frequencies were summarized and presented as proportions and 95% confidence intervals (CI) and continuous outcomes as mean (95% CI). Comparisons were made across methods of anastomosis. Overall, 29/205 dogs (0.14, 95% CI 0.10-00.19) had dehiscence, including 21/134 dogs (0.16, 0.11-0.23) undergoing hand-sutured anastomosis and 8/71 dogs (0.11, 0.06-0.21) undergoing stapled anastomosis. There was no significant difference in the frequency of dehiscence across anastomosis methods (χ(2), P = .389). The mean (95% CI) surgery duration of 140 minutes (132-147) for hand- sutured anastomoses and 108 minutes (99-119) for stapled anastomoses was significantly different (t-test, P < .001). No significant difference in frequency of dehiscence was noted between hand- sutured and stapled anastomoses in dogs but surgery duration is significantly reduced by the use of staples for intestinal closure. © Copyright 2015 by The American College of Veterinary Surgeons.
NASA Astrophysics Data System (ADS)
Datteri, Ryan; Asman, Andrew J.; Landman, Bennett A.; Dawant, Benoit M.
2014-03-01
Multi-atlas registration-based segmentation is a popular technique in the medical imaging community, used to transform anatomical and functional information from a set of atlases onto a new patient that lacks this information. The accuracy of the projected information on the target image is dependent on the quality of the registrations between the atlas images and the target image. Recently, we have developed a technique called AQUIRC that aims at estimating the error of a non-rigid registration at the local level and was shown to correlate to error in a simulated case. Herein, we extend upon this work by applying AQUIRC to atlas selection at the local level across multiple structures in cases in which non-rigid registration is difficult. AQUIRC is applied to 6 structures, the brainstem, optic chiasm, left and right optic nerves, and the left and right eyes. We compare the results of AQUIRC to that of popular techniques, including Majority Vote, STAPLE, Non-Local STAPLE, and Locally-Weighted Vote. We show that AQUIRC can be used as a method to combine multiple segmentations and increase the accuracy of the projected information on a target image, and is comparable to cutting edge methods in the multi-atlas segmentation field.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lim, Karen; Small, William; Portelance, Lorraine
Purpose: Accurate target definition is vitally important for definitive treatment of cervix cancer with intensity-modulated radiotherapy (IMRT), yet a definition of clinical target volume (CTV) remains variable within the literature. The aim of this study was to develop a consensus CTV definition in preparation for a Phase 2 clinical trial being planned by the Radiation Therapy Oncology Group. Methods and Materials: A guidelines consensus working group meeting was convened in June 2008 for the purposes of developing target definition guidelines for IMRT for the intact cervix. A draft document of recommendations for CTV definition was created and used to aidmore » in contouring a clinical case. The clinical case was then analyzed for consistency and clarity of target delineation using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE), with kappa statistics as a measure of agreement between participants. Results: Nineteen experts in gynecological radiation oncology generated contours on axial magnetic resonance images of the pelvis. Substantial STAPLE agreement sensitivity and specificity values were seen for gross tumor volume (GTV) delineation (0.84 and 0.96, respectively) with a kappa statistic of 0.68 (p < 0.0001). Agreement for delineation of cervix, uterus, vagina, and parametria was moderate. Conclusions: This report provides guidelines for CTV definition in the definitive cervix cancer setting for the purposes of IMRT, building on previously published guidelines for IMRT in the postoperative setting.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gaffney, David K., E-mail: david.gaffney@hci.utah.edu; King, Bronwyn; Viswanathan, Akila N.
Purpose: The purpose of this study was to develop a radiation therapy (RT) contouring atlas and recommendations for women with postoperative and locally advanced vulvar carcinoma. Methods and Materials: An international committee of 35 expert gynecologic radiation oncologists completed a survey of the treatment of vulvar carcinoma. An initial set of recommendations for contouring was discussed and generated by consensus. Two cases, 1 locally advanced and 1 postoperative, were contoured by 14 physicians. Contours were compared and analyzed using an expectation-maximization algorithm for simultaneous truth and performance level estimation (STAPLE), and a 95% confidence interval contour was developed. The levelmore » of agreement among contours was assessed using a kappa statistic. STAPLE contours underwent full committee editing to generate the final atlas consensus contours. Results: Analysis of the 14 contours showed substantial agreement, with kappa statistics of 0.69 and 0.64 for cases 1 and 2, respectively. There was high specificity for both cases (≥99%) and only moderate sensitivity of 71.3% and 64.9% for cases 1 and 2, respectively. Expert review and discussion generated consensus recommendations for contouring target volumes and treatment for postoperative and locally advanced vulvar cancer. Conclusions: These consensus recommendations for contouring and treatment of vulvar cancer identified areas of complexity and controversy. Given the lack of clinical research evidence in vulvar cancer radiation therapy, the committee advocates a conservative and consistent approach using standardized recommendations.« less
Frequency-Modulated, Continuous-Wave Laser Ranging Using Photon-Counting Detectors
NASA Technical Reports Server (NTRS)
Erkmen, Baris I.; Barber, Zeb W.; Dahl, Jason
2014-01-01
Optical ranging is a problem of estimating the round-trip flight time of a phase- or amplitude-modulated optical beam that reflects off of a target. Frequency- modulated, continuous-wave (FMCW) ranging systems obtain this estimate by performing an interferometric measurement between a local frequency- modulated laser beam and a delayed copy returning from the target. The range estimate is formed by mixing the target-return field with the local reference field on a beamsplitter and detecting the resultant beat modulation. In conventional FMCW ranging, the source modulation is linear in instantaneous frequency, the reference-arm field has many more photons than the target-return field, and the time-of-flight estimate is generated by balanced difference- detection of the beamsplitter output, followed by a frequency-domain peak search. This work focused on determining the maximum-likelihood (ML) estimation algorithm when continuous-time photoncounting detectors are used. It is founded on a rigorous statistical characterization of the (random) photoelectron emission times as a function of the incident optical field, including the deleterious effects caused by dark current and dead time. These statistics enable derivation of the Cramér-Rao lower bound (CRB) on the accuracy of FMCW ranging, and derivation of the ML estimator, whose performance approaches this bound at high photon flux. The estimation algorithm was developed, and its optimality properties were shown in simulation. Experimental data show that it performs better than the conventional estimation algorithms used. The demonstrated improvement is a factor of 1.414 over frequency-domainbased estimation. If the target interrogating photons and the local reference field photons are costed equally, the optimal allocation of photons between these two arms is to have them equally distributed. This is different than the state of the art, in which the local field is stronger than the target return. The optimal processing of the photocurrent processes at the outputs of the two detectors is to perform log-matched filtering followed by a summation and peak detection. This implies that neither difference detection, nor Fourier-domain peak detection, which are the staples of the state-of-the-art systems, is optimal when a weak local oscillator is employed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cox, Brett W., E-mail: coxb@mskcc.org; Spratt, Daniel E.; Lovelock, Michael
2012-08-01
Purpose: Spinal stereotactic radiosurgery (SRS) is increasingly used to manage spinal metastases. However, target volume definition varies considerably and no consensus target volume guidelines exist. This study proposes consensus target volume definitions using common scenarios in metastatic spine radiosurgery. Methods and Materials: Seven radiation oncologists and 3 neurological surgeons with spinal radiosurgery expertise independently contoured target and critical normal structures for 10 cases representing common scenarios in metastatic spine radiosurgery. Each set of volumes was imported into the Computational Environment for Radiotherapy Research. Quantitative analysis was performed using an expectation maximization algorithm for Simultaneous Truth and Performance Level Estimation (STAPLE)more » with kappa statistics calculating agreement between physicians. Optimized confidence level consensus contours were identified using histogram agreement analysis and characterized to create target volume definition guidelines. Results: Mean STAPLE agreement sensitivity and specificity was 0.76 (range, 0.67-0.84) and 0.97 (range, 0.94-0.99), respectively, for gross tumor volume (GTV) and 0.79 (range, 0.66-0.91) and 0.96 (range, 0.92-0.98), respectively, for clinical target volume (CTV). Mean kappa agreement was 0.65 (range, 0.54-0.79) for GTV and 0.64 (range, 0.54-0.82) for CTV (P<.01 for GTV and CTV in all cases). STAPLE histogram agreement analysis identified optimal consensus contours (80% confidence limit). Consensus recommendations include that the CTV should include abnormal marrow signal suspicious for microscopic invasion and an adjacent normal bony expansion to account for subclinical tumor spread in the marrow space. No epidural CTV expansion is recommended without epidural disease, and circumferential CTVs encircling the cord should be used only when the vertebral body, bilateral pedicles/lamina, and spinous process are all involved or there is extensive metastatic disease along the circumference of the epidural space. Conclusions: This report provides consensus guidelines for target volume definition for spinal metastases receiving upfront SRS in common clinical situations.« less
An algorithm for optimal fusion of atlases with different labeling protocols
Iglesias, Juan Eugenio; Sabuncu, Mert Rory; Aganj, Iman; Bhatt, Priyanka; Casillas, Christen; Salat, David; Boxer, Adam; Fischl, Bruce; Van Leemput, Koen
2014-01-01
In this paper we present a novel label fusion algorithm suited for scenarios in which different manual delineation protocols with potentially disparate structures have been used to annotate the training scans (hereafter referred to as “atlases”). Such scenarios arise when atlases have missing structures, when they have been labeled with different levels of detail, or when they have been taken from different heterogeneous databases. The proposed algorithm can be used to automatically label a novel scan with any of the protocols from the training data. Further, it enables us to generate new labels that are not present in any delineation protocol by defining intersections on the underling labels. We first use probabilistic models of label fusion to generalize three popular label fusion techniques to the multi-protocol setting: majority voting, semi-locally weighted voting and STAPLE. Then, we identify some shortcomings of the generalized methods, namely the inability to produce meaningful posterior probabilities for the different labels (majority voting, semi-locally weighted voting) and to exploit the similarities between the atlases (all three methods). Finally, we propose a novel generative label fusion model that can overcome these drawbacks. We use the proposed method to combine four brain MRI datasets labeled with different protocols (with a total of 102 unique labeled structures) to produce segmentations of 148 brain regions. Using cross-validation, we show that the proposed algorithm outperforms the generalizations of majority voting, semi-locally weighted voting and STAPLE (mean Dice score 83%, vs. 77%, 80% and 79%, respectively). We also evaluated the proposed algorithm in an aging study, successfully reproducing some well-known results in cortical and subcortical structures. PMID:25463466
Pricing of Staple Foods at Supermarkets versus Small Food Stores
Caspi, Caitlin E.; Pelletier, Jennifer E.; Harnack, Lisa J.; Erickson, Darin J.; Laska, Melissa N.
2017-01-01
Prices affect food purchase decisions, particularly in lower-income communities, where access to a range of food retailers (including supermarkets) is limited. The aim of this study was to examine differences in staple food pricing between small urban food stores and the closest supermarkets, as well as whether pricing differentials varied based on proximity between small stores and larger retailers. In 2014, prices were measured for 15 staple foods during store visits in 140 smaller stores (corner stores, gas-marts, dollar stores, and pharmacies) in Minneapolis/St. Paul, MN and their closest supermarket. Mixed models controlling for store type were used to estimate the average price differential between: (a) smaller stores and supermarkets; (b) isolated smaller stores (>1 mile to closest supermarket) and non-isolated smaller stores; and (c) isolated smaller stores inside versus outside USDA-identified food deserts. On average, all items except white bread were 10–54% more expensive in smaller stores than in supermarkets (p < 0.001). Prices were generally not significantly different in isolated stores compared with non-isolated stores for most items. Among isolated stores, there were no price differences inside versus outside food deserts. We conclude that smaller food stores have higher prices for most staple foods compared to their closest supermarket, regardless of proximity. More research is needed to examine staple food prices in different retail spaces. PMID:28809795
Pricing of Staple Foods at Supermarkets versus Small Food Stores.
Caspi, Caitlin E; Pelletier, Jennifer E; Harnack, Lisa J; Erickson, Darin J; Lenk, Kathleen; Laska, Melissa N
2017-08-15
Prices affect food purchase decisions, particularly in lower-income communities, where access to a range of food retailers (including supermarkets) is limited. The aim of this study was to examine differences in staple food pricing between small urban food stores and the closest supermarkets, as well as whether pricing differentials varied based on proximity between small stores and larger retailers. In 2014, prices were measured for 15 staple foods during store visits in 140 smaller stores (corner stores, gas-marts, dollar stores, and pharmacies) in Minneapolis/St. Paul, MN and their closest supermarket. Mixed models controlling for store type were used to estimate the average price differential between: (a) smaller stores and supermarkets; (b) isolated smaller stores (>1 mile to closest supermarket) and non-isolated smaller stores; and (c) isolated smaller stores inside versus outside USDA-identified food deserts. On average, all items except white bread were 10-54% more expensive in smaller stores than in supermarkets ( p < 0.001). Prices were generally not significantly different in isolated stores compared with non-isolated stores for most items. Among isolated stores, there were no price differences inside versus outside food deserts. We conclude that smaller food stores have higher prices for most staple foods compared to their closest supermarket, regardless of proximity. More research is needed to examine staple food prices in different retail spaces.
On Evaluating Brain Tissue Classifiers without a Ground Truth
Martin-Fernandez, Marcos; Ungar, Lida; Nakamura, Motoaki; Koo, Min-Seong; McCarley, Robert W.; Shenton, Martha E.
2009-01-01
In this paper, we present a set of techniques for the evaluation of brain tissue classifiers on a large data set of MR images of the head. Due to the difficulty of establishing a gold standard for this type of data, we focus our attention on methods which do not require a ground truth, but instead rely on a common agreement principle. Three different techniques are presented: the Williams’ index, a measure of common agreement; STAPLE, an Expectation Maximization algorithm which simultaneously estimates performance parameters and constructs an estimated reference standard; and Multidimensional Scaling, a visualization technique to explore similarity data. We apply these different evaluation methodologies to a set eleven different segmentation algorithms on forty MR images. We then validate our evaluation pipeline by building a ground truth based on human expert tracings. The evaluations with and without a ground truth are compared. Our findings show that comparing classifiers without a gold standard can provide a lot of interesting information. In particular, outliers can be easily detected, strongly consistent or highly variable techniques can be readily discriminated, and the overall similarity between different techniques can be assessed. On the other hand, we also find that some information present in the expert segmentations is not captured by the automatic classifiers, suggesting that common agreement alone may not be sufficient for a precise performance evaluation of brain tissue classifiers. PMID:17532646
Isothermal folding of a light-up bio-orthogonal RNA origami nanoribbon.
Torelli, Emanuela; Kozyra, Jerzy Wieslaw; Gu, Jing-Ying; Stimming, Ulrich; Piantanida, Luca; Voïtchovsky, Kislon; Krasnogor, Natalio
2018-05-03
RNA presents intringuing roles in many cellular processes and its versatility underpins many different applications in synthetic biology. Nonetheless, RNA origami as a method for nanofabrication is not yet fully explored and the majority of RNA nanostructures are based on natural pre-folded RNA. Here we describe a biologically inert and uniquely addressable RNA origami scaffold that self-assembles into a nanoribbon by seven staple strands. An algorithm is applied to generate a synthetic De Bruijn scaffold sequence that is characterized by the lack of biologically active sites and repetitions larger than a predetermined design parameter. This RNA scaffold and the complementary staples fold in a physiologically compatible isothermal condition. In order to monitor the folding, we designed a new split Broccoli aptamer system. The aptamer is divided into two nonfunctional sequences each of which is integrated into the 5' or 3' end of two staple strands complementary to the RNA scaffold. Using fluorescence measurements and in-gel imaging, we demonstrate that once RNA origami assembly occurs, the split aptamer sequences are brought into close proximity forming the aptamer and turning on the fluorescence. This light-up 'bio-orthogonal' RNA origami provides a prototype that can have potential for in vivo origami applications.
Spohrer, Rebecca; Larson, Melanie; Maurin, Clémence; Laillou, Arnaud; Capanzana, Mario; Garrett, Greg S
2013-06-01
Food fortification is a viable strategy to improve the nutritional status of populations. In Southeast Asia, recent growth and consolidation of the food industry provides an opportunity to explore whether certain widely consumed processed foods could contribute to micronutrient status if they are made with adequately fortified staples and condiments. To estimate the potential contribution certain processed foods can make to micronutrient intake in Southeast Asia if they are made with fortified staples and condiments; e.g., via the inclusion of iodized salt in various processed foods in the Philippines, fortified wheat flour in instant noodles in Indonesia, and fortified vegetable oil in biscuits in Vietnam. For Indonesia, the Philippines, and Vietnam, a review of consumption trends, relevant policies, and industry practices was conducted using publicly available sources,food industry market data and research reports, and oral communication. These informed the estimates of the proportion of the Recommended Nutrient Intake (RNI) that could be delivered via select processed foods. In the Philippines, Indonesia, and Vietnam, the processed food industry is not always required to use fortified staples and condiments. In the Philippines, dried salted fish with iodized salt would provide 64% to 85% of the iodine RNI for women of reproductive age and 107% to 141% of the iodine RNI for children 1 to 6 years of age. In Indonesia, a 75-g pack of instant noodles (a highly consumed product) with fortified wheat flour would provide 45% to 51% of the iron RNI for children 4 to 6 years of age and 10% to 11% of the iron RNI for women of reproductive age. In Vietnam, biscuits containing vegetable oil are increasingly popular. One 35-g biscuit serving with fortified vegetable oil would provide 13% to 18% of the vitamin A RNI for children 4 to 6 years of age and 12% to 17% of the vitamin A RNI for women of reproductive age. Ensuring that fortified staples and condiments such as flour, salt, and vegetable oil are used in widely consumed processed foods would ensure that these foods contribute to improvement in micronutrient intake among populations in Southeast Asia, particularly as the consumption of these foods is increasing. Policymakers and nutrition program managers should consider the contribution to nutritional intake that fortified staples and condiments can provide through processed foods, in addition to being used for cooking in the home, and ensure that the food industry is required to use these fortified staples and condiments rather than nonfortified foods.
Estimated Dietary Intakes of Toxic Elements from Four Staple Foods in Najran City, Saudi Arabia.
Mohamed, Hatem; Haris, Parvez I; Brima, Eid I
2017-12-14
Exposure of the inhabitants of Najran area in Saudi Arabia to the toxic elements As, Cd, Cr, and Pb through foods has not been previously investigated. Exposure to such elements is an important public health issue, so the study described here was performed with the aim of determining estimated dietary intakes (EDIs) for these metals in Najran area. The As, Cd, Cr, and Pb concentrations in four staple foods (rice, wheat, red meat, and chicken) were determined by inductively coupled plasma-mass spectrometry. A food frequency questionnaire (FFQ) was completed by 80 study participants. These data were used to estimate dietary intakes of the metals in the four staple foods. The mean As, Cd, Cr, and Pb EDIs in the four food types were 1.1 × 10 -6 -2.6 × 10 -5 , 1.42 × 10 -5 -2.2 × 10 -4 , 3.4 × 10 -4 -8.0 × 10 -4 , and 2.3 × 10 -5 -2.1 × 10 -3 mg/kg bw day, respectively. Hazard Quotients (HQ) for all elements did not exceed one. The highest Pb concentration was found for chicken and the source of this toxic element in this food needs to be investigated in the future. The lowest As concentration was found for wheat highest in rice. The EDIs for all elements in the four food types were below the provisional tolerable weekly intakes set by the World Health Organization (WHO).
SU-E-J-101: Improved CT to CBCT Deformable Registration Accuracy by Incorporating Multiple CBCTs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Godley, A; Stephans, K; Olsen, L Sheplan
2015-06-15
Purpose: Combining prior day CBCT contours with STAPLE was previously shown to improve automated prostate contouring. These accurate STAPLE contours are now used to guide the planning CT to pre-treatment CBCT deformable registration. Methods: Six IGRT prostate patients with daily kilovoltage CBCT had their original planning CT and 9 CBCTs contoured by the same physician. These physician contours for the planning CT and each prior CBCT are deformed to match the current CBCT anatomy, producing multiple contour sets. These sets are then combined using STAPLE into one optimal set (e.g. for day 3 CBCT, combine contours produced using the planmore » plus day 1 and 2 CBCTs). STAPLE computes a probabilistic estimate of the true contour from this collection of contours by maximizing sensitivity and specificity. The deformation field from planning CT to CBCT registration is then refined by matching its deformed contours to the STAPLE contours. ADMIRE (Elekta Inc.) was used for this. The refinement does not force perfect agreement of the contours, typically Dice’s Coefficient (DC) of > 0.9 is obtained, and the image difference metric remains in the optimization of the deformable registration. Results: The average DC between physician delineated CBCT contours and deformed planning CT contours for the bladder, rectum and prostate was 0.80, 0.79 and 0.75, respectively. The accuracy significantly improved to 0.89, 0.84 and 0.84 (P<0.001 for all) when using the refined deformation field. The average time to run STAPLE with five scans and refine the planning CT deformation was 66 seconds on a Telsa K20c GPU. Conclusion: Accurate contours generated from multiple CBCTs provided guidance for CT to CBCT deformable registration, significantly improving registration accuracy as measured by contour DC. A more accurate deformation field is now available for transferring dose or electron density to the CBCT for adaptive planning. Research grant from Elekta.« less
Multi-atlas and label fusion approach for patient-specific MRI based skull estimation.
Torrado-Carvajal, Angel; Herraiz, Joaquin L; Hernandez-Tamames, Juan A; San Jose-Estepar, Raul; Eryaman, Yigitcan; Rozenholc, Yves; Adalsteinsson, Elfar; Wald, Lawrence L; Malpica, Norberto
2016-04-01
MRI-based skull segmentation is a useful procedure for many imaging applications. This study describes a methodology for automatic segmentation of the complete skull from a single T1-weighted volume. The skull is estimated using a multi-atlas segmentation approach. Using a whole head computed tomography (CT) scan database, the skull in a new MRI volume is detected by nonrigid image registration of the volume to every CT, and combination of the individual segmentations by label-fusion. We have compared Majority Voting, Simultaneous Truth and Performance Level Estimation (STAPLE), Shape Based Averaging (SBA), and the Selective and Iterative Method for Performance Level Estimation (SIMPLE) algorithms. The pipeline has been evaluated quantitatively using images from the Retrospective Image Registration Evaluation database (reaching an overlap of 72.46 ± 6.99%), a clinical CT-MR dataset (maximum overlap of 78.31 ± 6.97%), and a whole head CT-MRI pair (maximum overlap 78.68%). A qualitative evaluation has also been performed on MRI acquisition of volunteers. It is possible to automatically segment the complete skull from MRI data using a multi-atlas and label fusion approach. This will allow the creation of complete MRI-based tissue models that can be used in electromagnetic dosimetry applications and attenuation correction in PET/MR. © 2015 Wiley Periodicals, Inc.
M1.3 - a small scaffold for DNA origami
NASA Astrophysics Data System (ADS)
Said, Hassan; Schüller, Verena J.; Eber, Fabian J.; Wege, Christina; Liedl, Tim; Richert, Clemens
2012-12-01
The DNA origami method produces programmable nanoscale objects that form when one long scaffold strand hybridizes to numerous oligonucleotide staple strands. One scaffold strand is dominating the field: M13mp18, a bacteriophage-derived vector 7249 nucleotides in length. The full-length M13 is typically folded by using over 200 staple oligonucleotides. Here we report the convenient preparation of a 704 nt fragment dubbed ``M1.3'' as a linear or cyclic scaffold and the assembly of small origami structures with just 15-24 staple strands. A typical M1.3 origami is large enough to be visualized by TEM, but small enough to show a cooperativity in its assembly and thermal denaturation that is reminiscent of oligonucleotide duplexes. Due to its medium size, M1.3 origami with globally modified staples is affordable. As a proof of principle, two origami structures with globally 5'-capped staples were prepared and were shown to give higher UV-melting points than the corresponding assembly with unmodified DNA. M1.3 has the size of a gene, not a genome, and may function as a model for gene-based nanostructures. Small origami with M1.3 as a scaffold may serve as a workbench for chemical, physical, and biological experiments.The DNA origami method produces programmable nanoscale objects that form when one long scaffold strand hybridizes to numerous oligonucleotide staple strands. One scaffold strand is dominating the field: M13mp18, a bacteriophage-derived vector 7249 nucleotides in length. The full-length M13 is typically folded by using over 200 staple oligonucleotides. Here we report the convenient preparation of a 704 nt fragment dubbed ``M1.3'' as a linear or cyclic scaffold and the assembly of small origami structures with just 15-24 staple strands. A typical M1.3 origami is large enough to be visualized by TEM, but small enough to show a cooperativity in its assembly and thermal denaturation that is reminiscent of oligonucleotide duplexes. Due to its medium size, M1.3 origami with globally modified staples is affordable. As a proof of principle, two origami structures with globally 5'-capped staples were prepared and were shown to give higher UV-melting points than the corresponding assembly with unmodified DNA. M1.3 has the size of a gene, not a genome, and may function as a model for gene-based nanostructures. Small origami with M1.3 as a scaffold may serve as a workbench for chemical, physical, and biological experiments. Electronic supplementary information (ESI) available: Materials, full sequence of M1.3, alternative restriction reactions, sequences and origami designs, ALEX data, estimated cost of producing M13, additional melting data for origami, and MALDI spectra of individual capped oligonucleotides. See DOI: 10.1039/c2nr32393a
Estimated Dietary Intakes of Toxic Elements from Four Staple Foods in Najran City, Saudi Arabia
Haris, Parvez I.; Brima, Eid I.
2017-01-01
Exposure of the inhabitants of Najran area in Saudi Arabia to the toxic elements As, Cd, Cr, and Pb through foods has not been previously investigated. Exposure to such elements is an important public health issue, so the study described here was performed with the aim of determining estimated dietary intakes (EDIs) for these metals in Najran area. The As, Cd, Cr, and Pb concentrations in four staple foods (rice, wheat, red meat, and chicken) were determined by inductively coupled plasma-mass spectrometry. A food frequency questionnaire (FFQ) was completed by 80 study participants. These data were used to estimate dietary intakes of the metals in the four staple foods. The mean As, Cd, Cr, and Pb EDIs in the four food types were 1.1 × 10−6–2.6 × 10−5, 1.42 × 10−5–2.2 × 10−4, 3.4 × 10−4–8.0 × 10−4, and 2.3 × 10−5–2.1 × 10−3 mg/kg bw day, respectively. Hazard Quotients (HQ) for all elements did not exceed one. The highest Pb concentration was found for chicken and the source of this toxic element in this food needs to be investigated in the future. The lowest As concentration was found for wheat highest in rice. The EDIs for all elements in the four food types were below the provisional tolerable weekly intakes set by the World Health Organization (WHO). PMID:29240693
21 CFR 878.4760 - Removable skin staple.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Removable skin staple. 878.4760 Section 878.4760...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4760 Removable skin staple. (a) Identification. A removable skin staple is a staple-like device intended to connect external tissues temporarily...
Serosal Laceration During Firing of Powered Linear Stapler Is a Predictor of Staple Malformation.
Matsuzawa, Fumihiko; Homma, Shigenori; Yoshida, Tadashi; Konishi, Yuji; Shibasaki, Susumu; Ishikawa, Takahisa; Kawamura, Hideki; Takahashi, Norihiko; Iijima, Hiroaki; Taketomi, Akinobu
2017-12-01
Although several types of staplers have been developed, staple-line leaks have been a great problem in gastrointestinal surgery. Powered linear staplers were recently developed to further reduce the risk of tissue trauma during laparoscopic surgery. The aim of this study was to identify the factors that predict staple malformation and determine the effect of precompression and slow firing on the staple formation of this novel powered stapling method. Porcine stomachs were divided using an endoscopic powered linear stapler with gold reloads. We divided the specimens into 9 groups according to the precompression time (0/60/180 seconds) and firing time (0/60/180 seconds). The occurrence and length of laceration and the shape of the staples were evaluated. We examined the factors influencing successful stapling and investigated the key factors for staple malformation. Precompression significantly decreased the occurrence and length of serosal laceration. Precompression and slow firing significantly improved the optimal stapling formation rate. Univariate analysis showed that the precompression time (0 seconds), firing time (0 seconds), and presence of serosal laceration were significantly associated with a low optimal formation rate. Multivariate analysis showed that these three factors were associated independently with low optimal formation rate and that the presence of serosal laceration was the only factor that could be detected during the stapling procedure. We have shown that serosal laceration is a predictor of staple malformation and demonstrated the importance of precompression and slow stapling when using the powered stapling method.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-27
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Certain Polyester Staple... certain polyester staple fiber from Taiwan. The period of review is May 1, 2008, through April 30, 2009... polyester staple fiber (PSF) from Taiwan. See Certain Polyester Staple Fiber From Taiwan: Preliminary...
Nováček, V; Tran, T N; Klinge, U; Tolba, R H; Staat, M; Bronson, D G; Miesse, A M; Whiffen, J; Turquier, F
2012-10-11
The impact of surgical staplers on tissues has been studied mostly in an empirical manner. In this paper, finite element method was used to clarify the mechanics of tissue stapling and associated phenomena. Various stapling modalities and several designs of circular staplers were investigated to evaluate the impact of the device on tissues and mechanical performance of the end-to-end colorectal anastomosis. Numerical simulations demonstrated that a single row of staples is not adequate to resist leakage due to non-linear buckling and opening of the tissue layers between two adjacent staples. Compared to the single staple row configuration, significant increase in stress experienced by the tissue at the inner staple rows was observed in two and three rows designs. On the other hand, adding second and/or third staple row had no effect on strain in the tissue inside the staples. Variable height design with higher staples in outer rows significantly reduced the stresses and strains in outer rows when compared to the same configuration with flat cartridge. Copyright © 2012 Elsevier Ltd. All rights reserved.
Digital Waveguide Architectures for Virtual Musical Instruments
NASA Astrophysics Data System (ADS)
Smith, Julius O.
Digital sound synthesis has become a standard staple of modern music studios, videogames, personal computers, and hand-held devices. As processing power has increased over the years, sound synthesis implementations have evolved from dedicated chip sets, to single-chip solutions, and ultimately to software implementations within processors used primarily for other tasks (such as for graphics or general purpose computing). With the cost of implementation dropping closer and closer to zero, there is increasing room for higher quality algorithms.
Tirima, Simba; Bartrem, Casey; von Lindern, Ian; von Braun, Margrit; Lind, Douglas; Anka, Shehu Mohamed; Abdullahi, Aishat
2018-05-01
In 2010, an estimated 400 to 500 children died of acute lead poisoning associated with artisanal gold mining in Zamfara, Nigeria. Processing of gold ores containing up to 10% lead within residential compounds put residents, especially children, at the highest risk. Principal routes of exposure were incidental ingestion and inhalation of contaminated soil and dusts. Several Nigerian and international health organizations collaborated to reduce lead exposures through environmental remediation and medical treatment. The contribution of contaminated food to total lead exposure was assessed during the environmental health response. Objectives of this investigation were to assess the influence of cultural/dietary habits on lead exposure pathways and estimate the contribution of contaminated food to children's blood lead levels (BLLs). A survey of village dietary practices and staple food lead content was conducted to determine dietary composition, caloric intakes, and lead intake. Potential blood lead increments were estimated using bio-kinetic modeling techniques. Most dietary lead exposure was associated with contamination of staple cereal grains and legumes during post-harvest processing and preparation in contaminated homes. Average post-harvest and processed cereal grain lead levels were 0.32mg/kg and 0.85mg/kg dry weight, respectively. Age-specific food lead intake ranged from 7 to 78μg/day. Lead ingestion and absorption were likely aggravated by the dusty environment, fasting between meals, and nutritional deficiencies. Contamination of staple cereal grains by highly bioavailable pulverized ores could account for as much as 11%-34% of children's BLLs during the epidemic, and were a continuing source after residential soil remediation until stored grain inventories were exhausted. Copyright © 2017. Published by Elsevier B.V.
Carles, Montserrat; Fechter, Tobias; Nemer, Ursula; Nanko, Norbert; Mix, Michael; Nestle, Ursula; Schaefer, Andrea
2015-12-21
PET/CT plays an important role in radiotherapy planning for lung tumors. Several segmentation algorithms have been proposed for PET tumor segmentation. However, most of them do not take into account respiratory motion and are not well validated. The aim of this work was to evaluate a semi-automated contrast-oriented algorithm (COA) for PET tumor segmentation adapted to retrospectively gated (4D) images. The evaluation involved a wide set of 4D-PET/CT acquisitions of dynamic experimental phantoms and lung cancer patients. In addition, segmentation accuracy of 4D-COA was compared with four other state-of-the-art algorithms. In phantom evaluation, the physical properties of the objects defined the gold standard. In clinical evaluation, the ground truth was estimated by the STAPLE (Simultaneous Truth and Performance Level Estimation) consensus of three manual PET contours by experts. Algorithm evaluation with phantoms resulted in: (i) no statistically significant diameter differences for different targets and movements (Δφ = 0.3 ± 1.6 mm); (ii) reproducibility for heterogeneous and irregular targets independent of user initial interaction and (iii) good segmentation agreement for irregular targets compared to manual CT delineation in terms of Dice Similarity Coefficient (DSC = 0.66 ± 0.04), Positive Predictive Value (PPV = 0.81 ± 0.06) and Sensitivity (Sen. = 0.49 ± 0.05). In clinical evaluation, the segmented volume was in reasonable agreement with the consensus volume (difference in volume (%Vol) = 40 ± 30, DSC = 0.71 ± 0.07 and PPV = 0.90 ± 0.13). High accuracy in target tracking position (ΔME) was obtained for experimental and clinical data (ΔME(exp) = 0 ± 3 mm; ΔME(clin) 0.3 ± 1.4 mm). In the comparison with other lung segmentation methods, 4D-COA has shown the highest volume accuracy in both experimental and clinical data. In conclusion, the accuracy in volume delineation, position tracking and its robustness on highly irregular target movements, make this algorithm a useful tool for 4D-PET based volume definition for radiotherapy planning of lung cancer and may help to improve the reproducibility in PET quantification for therapy response assessment and prognosis.
NASA Astrophysics Data System (ADS)
Carles, Montserrat; Fechter, Tobias; Nemer, Ursula; Nanko, Norbert; Mix, Michael; Nestle, Ursula; Schaefer, Andrea
2015-12-01
PET/CT plays an important role in radiotherapy planning for lung tumors. Several segmentation algorithms have been proposed for PET tumor segmentation. However, most of them do not take into account respiratory motion and are not well validated. The aim of this work was to evaluate a semi-automated contrast-oriented algorithm (COA) for PET tumor segmentation adapted to retrospectively gated (4D) images. The evaluation involved a wide set of 4D-PET/CT acquisitions of dynamic experimental phantoms and lung cancer patients. In addition, segmentation accuracy of 4D-COA was compared with four other state-of-the-art algorithms. In phantom evaluation, the physical properties of the objects defined the gold standard. In clinical evaluation, the ground truth was estimated by the STAPLE (Simultaneous Truth and Performance Level Estimation) consensus of three manual PET contours by experts. Algorithm evaluation with phantoms resulted in: (i) no statistically significant diameter differences for different targets and movements (Δ φ =0.3+/- 1.6 mm); (ii) reproducibility for heterogeneous and irregular targets independent of user initial interaction and (iii) good segmentation agreement for irregular targets compared to manual CT delineation in terms of Dice Similarity Coefficient (DSC = 0.66+/- 0.04 ), Positive Predictive Value (PPV = 0.81+/- 0.06 ) and Sensitivity (Sen. = 0.49+/- 0.05 ). In clinical evaluation, the segmented volume was in reasonable agreement with the consensus volume (difference in volume (%Vol) = 40+/- 30 , DSC = 0.71+/- 0.07 and PPV = 0.90+/- 0.13 ). High accuracy in target tracking position (Δ ME) was obtained for experimental and clinical data (Δ ME{{}\\text{exp}}=0+/- 3 mm; Δ ME{{}\\text{clin}}=0.3+/- 1.4 mm). In the comparison with other lung segmentation methods, 4D-COA has shown the highest volume accuracy in both experimental and clinical data. In conclusion, the accuracy in volume delineation, position tracking and its robustness on highly irregular target movements, make this algorithm a useful tool for 4D-PET based volume definition for radiotherapy planning of lung cancer and may help to improve the reproducibility in PET quantification for therapy response assessment and prognosis.
Prospects for genomic selection in cassava breeding
USDA-ARS?s Scientific Manuscript database
Cassava (Manihot esculenta Crantz) is a clonally propagated staple food crop in the tropics. Genomic selection (GS) has been implemented at three breeding institutions in Africa in order to reduce cycle times. Initial studies provided promising estimates of predictive abilities. Here, we expand on p...
Comparison of endostapler performance in challenging tissue applications.
Contini, Elizabeth; Whiffen, Jennifer; Bronson, Dwight
2013-01-01
Surgical staplers are frequently used in a variety of applications, demanding exacting instrument performance over a huge range of tissue compositions and disease states. The shape of a staple that is formed by a stapling device is one industry-accepted indicator of device performance; typically a B-shaped staple is considered the gold standard for staple formation. This B shape allows blood flow through the tissue, which is one important factor in the healing events that take place clinically after stapling. With the use of an animal model, this ex vivo study investigated staple formation when thick tissue endoscopic staplers were used on challenging and variable tissue. The setting was a corporate institution in the United States. Two 60-mm linear endoscopic thick tissue reloads, a varied-height stapler (VHS), and a single-height stapler (SHS) were fired on 7 different regions of porcine stomach. Resultant staple formation was assessed per region of the stomach and evaluated for proper B-shaped staple formation and staple malformation. The VHS reload had significantly better B-shaped formation (P<.001) for all regions of the stomach and reduced occurrence of malformed staples in 5 of the 7 regions compared with the SHS reload, wherein the remaining 2 regions exhibited comparable malform occurrence. This study compared 2 thick tissue reloads and found that the VHS reload had superior outcomes, with respect to staple formation, compared with the SHS reload. Copyright © 2012 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.
Improving the side-to-side stapled anastomosis: comparison of staplers for robust crotch formation.
Kimura, Masahiro; Kuwabara, Yoshiyuki; Taniwaki, Satoshi; Mitsui, Akira; Shibata, Yasuyuki; Ueno, Shuhei
2018-01-01
Few studies have investigated the burst pressure of side-to-side anastomoses comparing different stapling devices that are commercially available. We conducted side-to-side anastomoses with a variety of staplers and compared burst pressure in the crotch of the anastomoses. Nagoya City East Medical Center. We conducted side-to-side anastomoses with 9 staplers with different shapes and forms. Fresh pig small intestines were used. A side-to-side anastomosis was performed between 2 intestine specimens using a linear stapler. The burst pressure of the anastomosis was recorded. In total, 45 staplers were used for this experiment. The site of leakage in all cases was the crotch. Regarding the influence of the number of staple rows, the burst pressure in 3-row staplers was significantly higher than in 2-row staplers. With regard to the relationship between staple height and burst pressure, staples with a height slightly shorter than the intestinal thickness showed the highest burst pressure. In a comparison of staplers with uniform staple heights and stamplers with staples of 3 different heights, the latter had significantly lower burst pressures. Neoveil significantly increased the burst pressure in the crotch and contributed to the highest burst pressure of all the staplers used in this experiment. In this experiment, we defined the important factors that influence burst pressure at the crotch of a stapled, side-to-side anastomosis. These factors include the number of staple rows, the height of the staple compared with the thickness of the tissue, uniformity of staple height, and reinforcement of the staple line. In any surgical case requiring intestinal anastomosis, selection of a stapler is a critical step. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.
ARAUJO, Sergio Eduardo Alonso; HORCEL, Lucas de Araujo; SEID, Victor Edmond; BERTONCINI, Alexandre Bruno; KLAJNER, Sidney
2016-01-01
ABSTRACT Background: Stapled hemorrhoidopexy is associated with less postoperative pain and faster recovery. However, it may be associated with a greater risk of symptomatic recurrence. We hypothesized that undertaking a limited surgical excision of hemorrhoid disease after stapling may be a valid approach for selected patients. Aim: To compare long-term results after stapled hemorrhoidopexy with and without complementation with closed excisional technique. Method: In a retrospective uni-institutional cohort study, sixty-five (29 men) patients underwent stapled hemorrhoidopexy and 21 (13 men) underwent stapled hemorrhoidopexy with excision. The same surgeons operated on all cases. Patients underwent stapled hemorrhoidectomy associated with excisional surgery if symptoms attributable to external hemorrhoid piles were observed preoperatively, or if residual prolapse or bulky external disease was observed after the firing of the stapler. A closed excisional diathermy hemorrhoidectomy without vascular ligation was utilized in all complemented cases. All clinical variables were obtained from a questionnaire evaluation obtained through e-mail, telephone interview, or office follow-up. Results: The median duration of postoperative follow-up was 48.5 (6-40) months. Patients with grades 3 and 4 hemorrhoid disease were operated on more frequently using stapled hemorrhoidopexy complemented with excisional technique (95.2% vs. 55.4%, p=0.001). Regarding respectively stapled hemorrhoidopexy and stapled hemorrhoidopexy complemented with excision, there was no difference between the techniques in relation to symptom recurrence (43% and 33%, p=0.45) and median interval between surgery and symptom recurrence (30 (8-84) and 38.8 (8-65) months, p=0.80). Eight (12.3%) patients were re-operated after stapled hemorrhoidopexy and 2 (9.6%), after hemorrhoidopexy with excision (p=0.78). Patient distribution in both groups according to the degree of postoperative satisfaction was similar (p=0.97). Conclusion: Stapled hemorrhoidopexy combined with an excisional technique was effective for more advanced hemorrhoid disease. The combination may have prevented symptomatic recurrence associated to stapled hemorrhoidopexy alone. PMID:27759778
7 CFR 457.105 - Extra long staple cotton crop insurance provisions.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 6 2014-01-01 2014-01-01 false Extra long staple cotton crop insurance provisions... long staple cotton crop insurance provisions. The extra long staple cotton crop insurance provisions... Crop Insurance Corporation ELS Cotton Crop Provisions 1. Definitions Cotton. Varieties identified as...
7 CFR 457.105 - Extra long staple cotton crop insurance provisions.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 6 2012-01-01 2012-01-01 false Extra long staple cotton crop insurance provisions... long staple cotton crop insurance provisions. The extra long staple cotton crop insurance provisions... Crop Insurance Corporation ELS Cotton Crop Provisions 1. Definitions Cotton. Varieties identified as...
7 CFR 457.105 - Extra long staple cotton crop insurance provisions.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 6 2013-01-01 2013-01-01 false Extra long staple cotton crop insurance provisions... long staple cotton crop insurance provisions. The extra long staple cotton crop insurance provisions... Crop Insurance Corporation ELS Cotton Crop Provisions 1. Definitions Cotton. Varieties identified as...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-18
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... duty order on certain polyester staple fiber (``PSF'') from the People's Republic of China (``PRC''). See Certain Polyester Staple Fiber From the People's Republic of China: Notice of Preliminary Results...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-21
... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839] Certain Polyester Staple... certain polyester staple fiber (polyester staple fiber) from the Republic of Korea (Korea) for the period..., 2013, the Department initiated an administrative review of the antidumping duty order on polyester...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-16
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Certain Polyester Staple... administrative review of the antidumping duty order on certain polyester staple fiber from Taiwan. See Certain Polyester Staple Fiber from Taiwan: Preliminary Results of Antidumping Duty Administrative Review, 75 FR...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-09
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... polyester staple fiber from the PRC. See Initiation of Antidumping and Countervailing Duty Administrative...
26 CFR 301.269B-1 - Stapled foreign corporations.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 26 Internal Revenue 18 2012-04-01 2012-04-01 false Stapled foreign corporations. 301.269B-1....269B-1 Stapled foreign corporations. In accordance with section 269B(a)(1), a stapled foreign corporation is subject to the same taxes that apply to a domestic corporation under Title 26 of the Internal...
26 CFR 301.269B-1 - Stapled foreign corporations.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Stapled foreign corporations. 301.269B-1....269B-1 Stapled foreign corporations. In accordance with section 269B(a)(1), a stapled foreign corporation is subject to the same taxes that apply to a domestic corporation under Title 26 of the Internal...
26 CFR 301.269B-1 - Stapled foreign corporations.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 26 Internal Revenue 18 2013-04-01 2013-04-01 false Stapled foreign corporations. 301.269B-1....269B-1 Stapled foreign corporations. In accordance with section 269B(a)(1), a stapled foreign corporation is subject to the same taxes that apply to a domestic corporation under title 26 of the Internal...
26 CFR 301.269B-1 - Stapled foreign corporations.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 26 Internal Revenue 18 2014-04-01 2014-04-01 false Stapled foreign corporations. 301.269B-1....269B-1 Stapled foreign corporations. In accordance with section 269B(a)(1), a stapled foreign corporation is subject to the same taxes that apply to a domestic corporation under title 26 of the Internal...
26 CFR 1.269B-1 - Stapled foreign corporations.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 26 Internal Revenue 3 2010-04-01 2010-04-01 false Stapled foreign corporations. 1.269B-1 Section 1... (CONTINUED) INCOME TAXES Items Not Deductible § 1.269B-1 Stapled foreign corporations. (a) Treatment as a domestic corporation—(1) General rule. Except as otherwise provided, if a foreign corporation is a stapled...
26 CFR 301.269B-1 - Stapled foreign corporations.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 26 Internal Revenue 18 2011-04-01 2011-04-01 false Stapled foreign corporations. 301.269B-1....269B-1 Stapled foreign corporations. In accordance with section 269B(a)(1), a stapled foreign corporation is subject to the same taxes that apply to a domestic corporation under Title 26 of the Internal...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-01
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... administrative review of the antidumping duty order on certain polyester staple fiber from the PRC. See...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-09
... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839] Certain Polyester Staple... Polyester staple fiber (``PSF'') covered by the scope of the order is defined as synthetic staple fibers, not carded, combed or otherwise processed for spinning, of polyesters measuring 3.3 decitex (3 denier...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-11
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Certain Polyester Staple... Department) initiated an administrative review of the antidumping duty order on certain polyester staple fiber from Taiwan for the period May 1, 2010, through April 30, 2011.\\1\\ In Certain Polyester Staple...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-08
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber from... Eastern Textile Limited with regard to the antidumping duty order on polyester staple fiber from Taiwan... on polyester staple fiber from Taiwan to determine whether FENC was the successor-in-interest to FET...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-20
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber from... antidumping duty order on polyester staple fiber from Taiwan. The period of review is May 1, 2009, through... duty order on polyester staple fiber from Taiwan with respect to respondents Nan Ya Plastics...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-28
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber From... duty order on polyester staple fiber (PSF) from Taiwan. The period of review is May 1, 2011, through... Results. None were received. \\1\\ See Polyester Staple Fiber From Taiwan: Preliminary Results of...
76 FR 58040 - Certain Polyester Staple Fiber From Korea and Taiwan
Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-19
... Polyester Staple Fiber From Korea and Taiwan Determination On the basis of the record \\1\\ developed in the... antidumping duty orders on certain polyester staple fiber from Korea and Taiwan would be likely to lead to...), entitled Certain Polyester Staple Fiber From Korea and Taiwan: Investigation Nos. 731-TA-825 and 826...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-09
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... administrative review of the antidumping duty order on certain polyester staple fiber from the PRC. See...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-10
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... initiation of the administrative review of the antidumping duty order on certain polyester staple fiber from...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-02
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... polyester staple fiber from the PRC.\\1\\ On February 9, 2012 the Department partially extended the deadline...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-17
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... results of the administrative review of certain polyester staple fiber from the People's Republic of China... administrative review of the antidumping duty order on certain polyester staple fiber from the PRC. See...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-10
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... administrative review of certain polyester staple fiber (``PSF'') from the People's Republic of China (``PRC''), covering the period June 1, 2008--May 31, 2009. See Certain Polyester Staple Fiber From the People's...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-24
... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839] Certain Polyester Staple... on polyester staple fiber from Korea. See Antidumping or Countervailing Duty Order, Finding, or..., 76 FR 37781 (June 28, 2011). Scope of the Order Polyester staple fiber covered by the scope of the...
Man-I, Mariko; Suda, Koichi; Kikuchi, Kenji; Tanaka, Tsuyoshi; Furuta, Shimpei; Nakauchi, Masaya; Ishikawa, Ken; Ishida, Yoshinori; Uyama, Ichiro
2015-11-01
A delta-shaped anastomosis in totally laparoscopic Billroth I gastrectomy could be performed easily and sufficiently using only laparoscopic linear staplers. However, the restricted maneuverability and severe blurring of these staplers along with their limited hemostability induced strain. In this study, we determined the feasibility and safety of performing delta-shaped anastomosis using the Endo GIA™ Reloads with Tri-Staple™ Technology combined with Endo GIA™ Ultra Universal stapler (Tri-Staple) with a particular focus on short-term surgical outcomes. We performed a single-institutional prospective interventional study (UMIN 000008014). The Tri-Staple was prospectively used on 23 consecutive patients who underwent a curative totally laparoscopic Billroth I gastrectomy with delta-shaped anastomosis. These patients were matched with the 19 patients previously treated using the ENDOPATH(®) ETS Articulating Linear Cutters (ETS) on clinical and demographic characteristics. There were no differences between the groups in anastomosis-related local complications, morbidity, non-anastomosis-related local complications, total systemic complications, and short-term outcomes with the exception of significantly reduced blood loss in the Tri-Staple group (ETS vs. Tri-Staple: 37 [10-306] vs. 15 [5-210] mL, p = 0.02). Intraoperative bleeding from the staple line was significantly reduced in the Tri-Staple group. The postoperative drain indwelling period (ETS vs. Tri-Staple, 6 [4-10] vs. 4 [2-43] days, p = 0.032), fasting period (5 [3-7] vs. 3 [3-24] days, p = 0.022), and hospital stay (14 [10-47] vs. 11 [6-58] days, p = 0.025) were significantly shorter in the Tri-Staple group. There was no mortality in this series. Acceleration assessed as indices of blurring of stapler tip might have a significant adverse influence on staple-line bleeding at stapling sites. Totally laparoscopic Billroth I distal gastrectomy using Tri-Staple was feasible and safe with favorable short-term surgical outcomes. Reduced blurring while stapling may be a novel endpoint which newly developed stapling devices should target.
Characterization of yield reduction in Ethiopia using a GIS-based crop water balance model
Senay, G.B.; Verdin, J.
2003-01-01
In many parts of sub-Saharan Africa, subsistence agriculture is characterized by significant fluctuations in yield and production due to variations in moisture availability to staple crops. Widespread drought can lead to crop failures, with associated deterioration in food security. Ground data collection networks are sparse, so methods using geospatial rainfall estimates derived from satellite and gauge observations, where available, have been developed to calculate seasonal crop water balances. Using conventional crop production data for 4 years in Ethiopia (1996-1999), it was found that water-limited and water-unlimited growing regions can be distinguished. Furthermore, maize growing conditions are also indicative of conditions for sorghum. However, another major staple, teff, was found to behave sufficiently differently from maize to warrant studies of its own.
Design and structure of stapled peptides binding to estrogen receptors.
Phillips, Chris; Roberts, Lee R; Schade, Markus; Bazin, Richard; Bent, Andrew; Davies, Nichola L; Moore, Rob; Pannifer, Andrew D; Pickford, Andrew R; Prior, Stephen H; Read, Christopher M; Scott, Andrew; Brown, David G; Xu, Bin; Irving, Stephen L
2011-06-29
Synthetic peptides that specifically bind nuclear hormone receptors offer an alternative approach to small molecules for the modulation of receptor signaling and subsequent gene expression. Here we describe the design of a series of novel stapled peptides that bind the coactivator peptide site of estrogen receptors. Using a number of biophysical techniques, including crystal structure analysis of receptor-stapled peptide complexes, we describe in detail the molecular interactions and demonstrate that all-hydrocarbon staples modulate molecular recognition events. The findings have implications for the design of stapled peptides in general.
Deeley, MA; Chen, A; Datteri, R; Noble, J; Cmelak, A; Donnelly, EF; Malcolm, A; Moretti, L; Jaboin, J; Niermann, K; Yang, Eddy S; Yu, David S; Dawant, BM
2013-01-01
Image segmentation has become a vital and often rate limiting step in modern radiotherapy treatment planning. In recent years the pace and scope of algorithm development, and even introduction into the clinic, have far exceeded evaluative studies. In this work we build upon our previous evaluation of a registration driven segmentation algorithm in the context of 8 expert raters and 20 patients who underwent radiotherapy for large space-occupying tumors in the brain. In this work we tested four hypotheses concerning the impact of manual segmentation editing in a randomized single-blinded study. We tested these hypotheses on the normal structures of the brainstem, optic chiasm, eyes and optic nerves using the Dice similarity coefficient, volume, and signed Euclidean distance error to evaluate the impact of editing on inter-rater variance and accuracy. Accuracy analyses relied on two simulated ground truth estimation methods: STAPLE and a novel implementation of probability maps. The experts were presented with automatic, their own, and their peers’ segmentations from our previous study to edit. We found, independent of source, editing reduced inter-rater variance while maintaining or improving accuracy and improving efficiency with at least 60% reduction in contouring time. In areas where raters performed poorly contouring from scratch, editing of the automatic segmentations reduced the prevalence of total anatomical miss from approximately 16% to 8% of the total slices contained within the ground truth estimations. These findings suggest that contour editing could be useful for consensus building such as in developing delineation standards, and that both automated methods and even perhaps less sophisticated atlases could improve efficiency, inter-rater variance, and accuracy. PMID:23685866
ERIC Educational Resources Information Center
Giani, Matt S.
2015-01-01
The purpose of this study is to revisit the widely held assumption that the impact of socioeconomic background declines steadily across educational transitions, particularly at the postsecondary level. Sequential logit modeling, a staple methodological approach for estimating the relative impact of SES across educational stages, is applied to a…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bahig, Houda; Roberge, David, E-mail: david.roberge.chum@ssss.gouv.qc.ca; Bosch, Walter
Purpose: Peritumoral edema may harbor sarcoma cells. The extent of suspicious edema (SE) included in the treatment volume is subject to clinical judgment, balancing the risk of missing tumor cells with excess toxicity. Our goal was to determine variability in SE delineation by sarcoma radiation oncologists (RO). Methods and Materials: Twelve expert ROs were provided with T1 gadolinium and T2-weighted MR images of 10 patients with high-grade extremity soft-tissue sarcoma. Gross tumor volume, clinical target volume (CTV)3cm (3 cm longitudinal and 1.5 cm radial margin), and CTV2cm (2 cm longitudinal and 1 cm radial margin) were contoured by a singlemore » observer. Suspicious peritumoral edema, defined as abnormal signal on T2 images, was independently delineated by all 12 ROs. Contouring agreement was analyzed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results: The mean volumes of GTV, CTV2cm, and CTV3cm were, respectively, 130 cm{sup 3} (7-413 cm{sup 3}), 280 cm{sup 3} and 360 cm{sup 3}. The mean consensus volume computed using the STAPLE algorithm at 95% confidence interval was 188 cm{sup 3} (24-565 cm{sup 3}) with a substantial overall agreement corrected for chance (mean kappa = 0.71; range: 0.32-0.87). The minimum, maximum, and mean volume of SE (excluding the GTV) were 4, 182, and 58 cm{sup 3} (representing a median of 29% of the GTV volume). The median volume of SE not included in the CTV2cm and in the CTV3cm was 5 and 0.3 cm{sup 3}, respectively. There were 3 large tumors with >30 cm{sup 3} of SE not included in the CTV3cm volume. Conclusion: Despite the fact that SE would empirically seem to be a more subjective volume, a substantial or near-perfect interobserver agreement was observed in SE delineation in most cases with high-grade soft-tissue sarcomas of the extremity. A median of 97% of the consensus SE is within the CTV2cm (99.8% within the CTV3cm). In a minority of cases, however, significant expansion of the CTVs is required to cover SE.« less
Bahig, Houda; Roberge, David; Bosch, Walter; Levin, William; Petersen, Ivy; Haddock, Michael; Freeman, Carolyn; Delaney, Thomas F; Abrams, Ross A; Indelicato, Danny J; Baldini, Elizabeth H; Hitchcock, Ying; Kirsch, David G; Kozak, Kevin R; Wolfson, Aaron; Wang, Dian
2013-06-01
Peritumoral edema may harbor sarcoma cells. The extent of suspicious edema (SE) included in the treatment volume is subject to clinical judgment, balancing the risk of missing tumor cells with excess toxicity. Our goal was to determine variability in SE delineation by sarcoma radiation oncologists (RO). Twelve expert ROs were provided with T1 gadolinium and T2-weighted MR images of 10 patients with high-grade extremity soft-tissue sarcoma. Gross tumor volume, clinical target volume (CTV)3cm (3 cm longitudinal and 1.5 cm radial margin), and CTV2cm (2 cm longitudinal and 1 cm radial margin) were contoured by a single observer. Suspicious peritumoral edema, defined as abnormal signal on T2 images, was independently delineated by all 12 ROs. Contouring agreement was analyzed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. The mean volumes of GTV, CTV2cm, and CTV3cm were, respectively, 130 cm(3) (7-413 cm(3)), 280 cm(3) and 360 cm(3). The mean consensus volume computed using the STAPLE algorithm at 95% confidence interval was 188 cm(3) (24-565 cm(3)) with a substantial overall agreement corrected for chance (mean kappa = 0.71; range: 0.32-0.87). The minimum, maximum, and mean volume of SE (excluding the GTV) were 4, 182, and 58 cm(3) (representing a median of 29% of the GTV volume). The median volume of SE not included in the CTV2cm and in the CTV3cm was 5 and 0.3 cm(3), respectively. There were 3 large tumors with >30 cm(3) of SE not included in the CTV3cm volume. Despite the fact that SE would empirically seem to be a more subjective volume, a substantial or near-perfect interobserver agreement was observed in SE delineation in most cases with high-grade soft-tissue sarcomas of the extremity. A median of 97% of the consensus SE is within the CTV2cm (99.8% within the CTV3cm). In a minority of cases, however, significant expansion of the CTVs is required to cover SE. Copyright © 2013 Elsevier Inc. All rights reserved.
Staple line reinforcement during sleeve gastrectomy with a new type of reinforced stapler.
El Moussaoui, Imad; Limbga, Augustin; Mehdi, Abdelilah
2018-04-01
Bleeding and staple-line leak, are the most common complications of laparoscopic sleeve gastrectomy. To decrease the incidence of this complications, a variety of intraoperative reinforcement of staple line is used. Reinforced GIA™ is a new automatic suture device with pre-attached synthetic tissue reinforcement, but no study has evaluated its use in sleeve gastrectomy. The objective of this study is to evaluate the efficacy and safety of this new staple line reinforcement technique in laparoscopic sleeve gastrectomy. We conducted a retrospective review of 290 patients who underwent laparoscopic sleeve gastrectomy between January 2013 and January 2016 in which reinforced GIA™ or standard GIA™ was used. Patients preoperative characteristics, Operative time, staple line leaks, staple line bleeds, stenosis, and complications requiring reoperation were collected. A total of 187 laparoscopic sleeve gastrectomy were performed with standard GIA and 103 with reinforced GIA™. Patient characteristics were not significantly different between the groups. The average operating time in the standard GIA group is 57.41±16.44 min against 50.9±14.12 min in the reinforced GIA group (P=0.006). Two staple line leaks developed in the standard GIA group and reoperated against no patients in the reinforced GIA group, without significant difference between the both groups (P=0.66). Staple line bleeds are less in the reinforced GIA group, only 23 (22.3%) against 78 (41.7%) cases in the standard GIA group (P=0.001). No patients of both groups developed gastric sleeve stenosis. During laparoscopic sleeve gastrectomy, the use of a reinforced stapler significantly reduces the operative time and staple line bleeding. No significant difference is evidenced in terms of reduction of staple line leaks with this reinforced stapler.
Committing Canadian sociology: developing a Canadian sociology and a sociology of Canada.
Matthews, Ralph
2014-05-01
This paper is a slightly revised version of the author's "Outstanding Career Award Lecture" presented at the Annual Meeting of the Canadian Sociological Association in Victoria, British Columbia on June 6, 2013. The paper distinguishes between Canadian Sociology and the Sociology of Canada. The former involves the explanatory stance that one takes to understanding Canada. The latter addresses the significant social dimensions that underlie Canadian social organization, culture, and behavior. I make a case for a Canadian Sociology that focuses on the unique features of Canadian society rather than adopting a comparative perspective. I also argue that there is a continuing need within the Sociology of Canada to address the issues of staples development. However, I argue that "new" staples analysis must have a directional change from that of the past, in that social processes now largely determine the pattern of staples development. Moreover, new staples analysis must include issues that were never part of earlier staples analysis, such as issues of environmental impacts and of staples depletion under conditions, such as climate change. The paper concludes by analyzing four factors that provide the dominant social contexts for analyzing modern staples development: (1) the rise of neoliberal government, (2) the implementation of globalization and its social consequences, (3) the assumption of aboriginal rights and entitlement, and (4) the rise of environmentalism. These factors were generally not considered in earlier staples approaches. They are critical to understanding the role of staples development and its impact on Canada in the present time.
Current Developments and Unusual Aspects in Gastrointestinal Surgical Stapling.
Frattini, Francesco; Amico, Francesco; Rausei, Stefano; Boni, Luigi; Rovera, Francesca; Dionigi, Gianlorenzo
2015-11-01
Stapling devices are used in gastrointestinal, gynecologic, thoracic, and many other surgeries to resect organs, transect tissues, and anastomose different structures. These devices became widely accepted standard practice in many gastrointestinal operations, especially since the successful advent of minimally invasive surgery. Despite the relevant advantages related to the use of a surgical stapler, we must also consider that these instruments may be at risk of failure. When any component fails, the patient is at risk of operative morbidity. Gastrointestinal surgical stapling technique still needs refinement in order to increase its reliability. Staple line reinforcement has been widely used and seems to effectively reduce anastomotic complications. Literature provides us with examples of studies supporting both bleeding and leakage reduction after staple line reinforcement, but high-quality evidence is not available to date. Semi-absorbable and nonabsorbable materials have been the earliest available. The use of bioabsorbable staple line reinforcement materials has recently become more widespread, and these materials are more widely used these days. Powered staplers were made available to the market some time ago and represent a rather unheard of aspect of endosurgical stapling. Despite powered staples being supposedly convenient compared with manual ones only one relevant article was found when searching the U.S. National Library of Medicine for "powered stapler." New surgical stapling devices are constantly developed and introduced on the market. Results with such devices depend on the stapler features but also surely vary according to the surgeon experience.
Fingerhut, A; Hay, J M; Elhadad, A; Lacaine, F; Flamant, Y
1995-09-01
Although used widely for supraperitoneal anastomoses, circular stapled anastomoses have never been proved better than hand-sewn anastomoses. In the one prospective controlled trial that studied these anastomoses specifically, the only significant difference found was that there were more clinically obvious leakages with the circular stapled variety, but not in the overall clinical and roentgenologic leakage rates. One hundred fifty-nine consecutive patients (88 men and 71 women, mean age 65.8 +/- 12.1 years) were randomized to undergo hand-sewn (n = 74) or circular stapled (n = 85) supraperitoneal colorectal anastomosis after left colectomy. Patient demographics were similar in both groups. Overall mortality was 1.3% (2 of 159; one in each group). No statistically significant difference (NS) was found in the rate of early complications, including anastomotic leakage (4 of 74 versus 6 of 85) in the hand-sewn and stapled anastomoses, respectively). Mishaps (n = 10) and hemorrhage (n = 5) occurred in the stapled group only. Stapled anastomoses took an average of 8 minutes less to perform (p < 0.001), but this time gain did not significantly influence the overall duration of operation (identical median times). The median duration of hospitalization was 13 and 14 days, respectively (NS). At 8 months there were 2 of 74 strictures in the hand-sewn group and 4 of 85 strictures in the stapled group (NS). According to these results, there seems to be no advantage of routine or regular use of stapling instruments for supraperitoneal colorectal anastomosis.
Bowel anastomoses: The theory, the practice and the evidence base
Goulder, Frances
2012-01-01
Since the introduction of stapling instruments in the 1970s various studies have compared the results of sutured and stapled bowel anastomoses. A literature search was performed from 1960 to 2010 and articles relating to small bowel, colonic and colorectal anastomotic techniques were reviewed. References from these articles were also reviewed, and relevant articles obtained. Either a stapled or sutured gastrointestinal tract anastomosis is acceptable in most situations. The available evidence suggests that in the following situations, however, particular anastomotic techniques may result in fewer complications: A stapled side-to-side ileocolic anastomosis is preferable following a right hemicolectomy for cancer. A stapled side-to-side anastomosis is likely also preferable after an ileocolic resection for Crohn’s disease. Colorectal anastomoses can be sutured or stapled with similar results, although the incidence of strictures is higher following stapled anastomoses. Following reversal of loop ileostomy there is some evidence to suggest that a stapled side-to-side anastomosis or sutured enterotomy closure (rather than spout resection and sutured anastomosis) results in fewer complications. Non-randomised data has indicated that small bowel anastomoses are best sutured in the trauma patient. This article reviews the theory, practice and evidence base behind the various gastrointestinal anastomoses to help the practising general surgeon make evidence based operative decisions. PMID:23293735
Su, Wen-Hao; He, Hong-Ju; Sun, Da-Wen
2017-03-24
Staple foods, including cereals, legumes, and root/tuber crops, dominate the daily diet of humans by providing valuable proteins, starch, oils, minerals, and vitamins. Quality evaluation of staple foods is primarily carried out on sensory (e.g. external defect, color), adulteration (e.g. species, origin), chemical (e.g. starch, proteins), mycotoxin (e.g. Fusarium toxin, aflatoxin), parasitic infection (e.g. weevil, beetle), and internal physiological (e.g. hollow heart, black heart) aspects. Conventional methods for the quality assessment of staple foods are always laborious, destructive, and time-consuming. Requirements for online monitoring of staple foods have been proposed to encourage the development of rapid, reagentless, and noninvasive techniques. Spectroscopic techniques, such as visible-infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance spectroscopy, and spectral imaging, have been introduced as promising analytical tools and applied for the quality evaluation of staple foods. This review summarizes the recent applications and progress of such spectroscopic techniques in determining various qualities of staple foods. Besides, challenges and future trends of these spectroscopic techniques are also presented.
A Discussion with Suzanne Fisher Staples: The Author as Writer and Cultural Observer.
ERIC Educational Resources Information Center
Sawyer, Walter E.; Sawyer, Jean C.
1993-01-01
Presents an interview with Suzanne Fisher Staples, author of the children's novel, "Shabanu, Daughter of the Wind." Discusses Staples' creative writing process, background, and the writer's role as cultural observer. (HB)
Tian, Yuan; Jiang, Yanhong; Li, Jingxu; Wang, Dongyuan; Zhao, Hui; Li, Zigang
2017-11-02
Stapled peptides have emerged as a new class of targeting molecules with high binding affinity and specificity for intracellular undruggable targets. Their ability to penetrate cell membranes is exceptionally intriguing but remains elusively and controversially discussed. To understand the effect of stapling architectures on their physiochemical properties and to aid in promoting their cell permeability, we report herein a comparative study on the physiochemical properties and cell permeability of stapled α-helical peptides with different types of crosslinks. We highlight the decisive impact of the intrinsic properties of the crosslinks on cell permeability rather than the helical contents of the peptides in model amphipathic sequences targeting estrogen receptor-coactivator interaction. We envision this finding to shed further light on the chemical optimization of stapled α-helical peptides or macrocyclic cell-penetrating peptides for enhanced cell penetration. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
USDA-ARS?s Scientific Manuscript database
Rice is the most important staple crop grown and consumed in Southeast Asia. Timely and reliable rice production estimates are therefore important in monitoring government development plans in the region and in mitigating the effects of extreme weather and climate change to address food insecurity. ...
A standardized safe hepatectomy; selective Glissonean transection using endolinear stapling devices.
Fujii, Masahiko; Shimada, Mitsuo; Satoru, Imura; Morine, Yuji; Ikemoto, Tetsuya; Soejima, Yuji
2007-01-01
Selective clamping of Glisson's pedicle at the hilum is effective for systematized hepatectomy. Because of the development of stapling devices, a Glissonean transection using a surgical stapler has been used widely. However, the risk of accidental stapling of the biliary confluence still remains. In this paper we report about a case that underwent selective Glissonean transection using an endolinear stapling device. We used this standardized technique in five patients without any major complications. The particular case to which we refer was a 71-year-old woman with hepatocellular carcinoma in the right lobe. The anterior and posterior branches of Glisson's pedicle were independently divided using an endolinear stapling device. The right hepatic lobectomy was achieved with little bleeding and in addition there was a shortened operation time and the postoperative course was uneventful. In the patient with liver cirrhosis, postoperative complications often related to liver failure. We herein advocate a standardized safe hepatectomy using endolinear stapling devices. We believe that the shortened operative time and decreased risk of complications by selective Glissonean transection as well as hepatic vein transection using stapling devices contribute to the improved short-term outcome.
Ciardo, Delia; Gerardi, Marianna Alessandra; Vigorito, Sabrina; Morra, Anna; Dell'acqua, Veronica; Diaz, Federico Javier; Cattani, Federica; Zaffino, Paolo; Ricotti, Rosalinda; Spadea, Maria Francesca; Riboldi, Marco; Orecchia, Roberto; Baroni, Guido; Leonardi, Maria Cristina; Jereczek-Fossa, Barbara Alicja
2017-04-01
Atlas-based automatic segmentation (ABAS) addresses the challenges of accuracy and reliability in manual segmentation. We aim to evaluate the contribution of specific-purpose in ABAS of breast cancer (BC) patients with respect to generic-purpose libraries. One generic-purpose and 9 specific-purpose libraries, stratified according to type of surgery and size of thorax circumference, were obtained from the computed tomography of 200 BC patients. Keywords about contralateral breast volume and presence of breast expander/prostheses were recorded. ABAS was validated on 47 independent patients, considering manual segmentation from scratch as reference. Five ABAS datasets were obtained, testing single-ABAS and multi-ABAS with simultaneous truth and performance level estimation (STAPLE). Center of mass distance (CMD), average Hausdorff distance (AHD) and Dice similarity coefficient (DSC) between corresponding ABAS and manual structures were evaluated and statistically significant differences between different surgeries, structures and ABAS strategies were investigated. Statistically significant differences between patients who underwent different surgery were found, with superior results for conservative-surgery group, and between different structures were observed: ABAS of heart, lungs, kidneys and liver was satisfactory (median values: CMD<2 mm, DSC≥0.80, AHD<1.5 mm), whereas chest wall, breast and spinal cord obtained moderate performance (median values: 2 mm ≤ CMD<5 mm, 0.60 ≤ DSC<0.80, 1.5 mm ≤ AHD<4 mm) and esophagus, stomach, brachial plexus and supraclavicular nodes obtained poor performance (median CMD≥5 mm, DSC<0.60, AHD≥4 mm). The application of STAPLE algorithm generally yields higher performance and the use of keywords improves results for breast ABAS. The homogeneity in the selection of atlases based on multiple anatomical and clinical features and the use of specific-purpose libraries can improve ABAS performance with respect to generic-purpose libraries. Copyright © 2016 Elsevier Ltd. All rights reserved.
Food price seasonality in Africa: Measurement and extent.
Gilbert, Christopher L; Christiaensen, Luc; Kaminski, Jonathan
2017-02-01
Everyone knows about seasonality. But what exactly do we know? This study systematically measures seasonal price gaps at 193 markets for 13 food commodities in seven African countries. It shows that the commonly used dummy variable or moving average deviation methods to estimate the seasonal gap can yield substantial upward bias. This can be partially circumvented using trigonometric and sawtooth models, which are more parsimonious. Among staple crops, seasonality is highest for maize (33 percent on average) and lowest for rice (16½ percent). This is two and a half to three times larger than in the international reference markets. Seasonality varies substantially across market places but maize is the only crop in which there are important systematic country effects. Malawi, where maize is the main staple, emerges as exhibiting the most acute seasonal differences. Reaching the Sustainable Development Goal of Zero Hunger requires renewed policy attention to seasonality in food prices and consumption.
Izbicki, J R; Gawad, K A; Quirrenbach, S; Hosch, S B; Breid, V; Knoefel, W T; Küpper, H U; Broelsch, C E
1998-07-01
Hospitals are facing increasing economic pressure. It therefore seems necessary to evaluate the efficiency and effectiveness of medical or surgical interventions. In this study 324 anastomoses (167 stapled and 157 hand-sewn) were performed after randomization during 200 elective operations [20.5% gastrectomies, 14% gastric resections (Billroth II), 15% Whipple's procedures, 4% segmental colonic resections, 18% right-sided hemicolectomies, 4% left-sided hemicolectomies, 22% sigmoid- or anterior rectal resections, 2.5% total colectomies with pouch-anal anastomoses] in 200 patients. Postoperative motility (time to full oral diet, time with naso-gastric tube) and hospitalization were comparable in both groups. Anastomotic insufficiency was observed in 2.1% of all patients, five after stapled and two after hand-sewn anastomoses. Hospital mortality was 1.5%. All stapled anastomoses were performed significantly (P < 0.001) faster. However, the cost of material for these anastomoses was significantly (P < 0.001) higher, resulting in significantly higher total costs for reconstruction. The time saving for the reconstruction did not influence the total operative time (except for stapled gastrectomy). Therefore, all operations with stapled reconstruction were more expensive than those with sutured reconstruction. The difference was significant for the gastrectomy (P < 0.01), colonic resection (P < 0.01) and sigmoid and rectal resection (P < 0.001) groups. Stapled and sutured anastomoses are equally effective. Stapled anastomoses are not efficient, however, and should be reserved for individual indications.
21 CFR 878.4750 - Implantable staple.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Implantable staple. 878.4750 Section 878.4750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4750 Implantable staple. (a...
21 CFR 878.4750 - Implantable staple.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implantable staple. 878.4750 Section 878.4750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4750 Implantable staple. (a...
21 CFR 878.4750 - Implantable staple.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Implantable staple. 878.4750 Section 878.4750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4750 Implantable staple. (a...
21 CFR 878.4750 - Implantable staple.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Implantable staple. 878.4750 Section 878.4750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4750 Implantable staple. (a...
21 CFR 878.4750 - Implantable staple.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Implantable staple. 878.4750 Section 878.4750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4750 Implantable staple. (a...
Watson, Angus J M; Hudson, Jemma; Wood, Jessica; Kilonzo, Mary; Brown, Steven R; McDonald, Alison; Norrie, John; Bruhn, Hanne; Cook, Jonathan A
2016-11-12
Two commonly performed surgical interventions are available for severe (grade II-IV) haemorrhoids; traditional excisional surgery and stapled haemorrhoidopexy. Uncertainty exists as to which is most effective. The eTHoS trial was designed to establish the clinical effectiveness and cost-effectiveness of stapled haemorrhoidopexy compared with traditional excisional surgery. The eTHoS trial was a large, open-label, multicentre, parallel-group, pragmatic randomised controlled trial done in adult participants (aged 18 years or older) referred to hospital for surgical treatment for grade II-IV haemorrhoids. Participants were randomly assigned (1:1) to receive either traditional excisional surgery or stapled haemorrhoidopexy. Randomisation was minimised according to baseline EuroQol 5 dimensions 3 level score (EQ-5D-3L), haemorrhoid grade, sex, and centre with an automated system to stapled haemorrhoidopexy or traditional excisional surgery. The primary outcome was area under the quality of life curve (AUC) measured with the EQ-5D-3L descriptive system over 24 months, assessed according to the randomised groups. The primary outcome measure was analysed using linear regression with adjustment for the minimisation variables. This trial is registered with the ISRCTN registry, number ISRCTN80061723. Between Jan 13, 2011, and Aug 1, 2014, 777 patients were randomised (389 to receive stapled haemorrhoidopexy and 388 to receive traditional excisional surgery). Stapled haemorrhoidopexy was less painful than traditional excisional surgery in the short term and surgical complication rates were similar between groups. The EQ-5D-3L AUC score was higher in the traditional excisional surgery group than the stapled haemorrhoidopexy group over 24 months; mean difference -0·073 (95% CI -0·140 to -0·006; p=0·0342). EQ-5D-3L was higher for stapled haemorrhoidopexy in the first 6 weeks after surgery, the traditional excisional surgery group had significantly better quality of life scores than the stapled haemorrhoidopexy group. 24 (7%) of 338 participants who received stapled haemorrhoidopexy and 33 (9%) of 352 participants who received traditional excisional surgery had serious adverse events. As part of a tailored management plan for haemorrhoids, traditional excisional surgery should be considered over stapled haemorrhoidopexy as the surgical treatment of choice. National Institute for Health Research Health Technology Assessment programme. Copyright © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.
USDA-ARS?s Scientific Manuscript database
In clonally propagated crops, non-additive genetic effects can be effectively exploited by the identification of superior genetic individuals as varieties. Cassava (Manihot esculenta Crantz) is a clonally propagated staple food crop that feeds hundreds of millions. We quantified the amount and natur...
USDA-ARS?s Scientific Manuscript database
Scope: Fumonisin (FB) intake can be high when maize is a dietary staple. We determined 1) urinary FB (UFB) in women consuming maize in high and low exposure communities in Guatemala, 2) the FB levels in maize, 3) the stoichiometric relationship between UFB and FB intake, and 4) the relative excreti...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-19
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of China: Partial Rescission of the Third Antidumping Duty... Request Administrative Review'' of the antidumping duty order on certain polyester staple fiber (``PSF...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-31
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of Antidumping Duty Administrative...) initiated an administrative review of the antidumping duty order on certain polyester staple fiber from...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-05
... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839] Certain Polyester Staple Fiber From the Republic of Korea: Rescission of Antidumping Duty Administrative Review AGENCY: Import... antidumping duty order on certain polyester staple fiber from the Republic of Korea (``the Order''). The...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-26
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber From... Commerce is initiating a changed- circumstances review of the antidumping duty order on polyester staple... previously accorded to Far Eastern Textile Limited with regard to the antidumping duty order on polyester...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-30
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of Antidumping Duty Administrative...) initiated an administrative review of the antidumping duty order on certain polyester staple fiber from...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-21
... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-1104 (Review)] Polyester Staple Fiber... Polyester Staple Fiber From China AGENCY: United States International Trade Commission. ACTION: Notice... CONTACT: Joanna Lo (202-205-1888), Office of Investigations, U.S. International Trade Commission, 500 E...
77 FR 60720 - Certain Polyester Staple Fiber From China
Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-04
... Fiber From China Determination On the basis of the record \\1\\ developed in the subject five-year review... certain polyester staple fiber from China would be likely to lead to continuation or recurrence of... (September 2012), entitled Certain Polyester Staple Fiber from China: Investigation No. 731-TA-1104 (Review...
7 CFR 28.303 - Standards for length of staple for American upland cotton.
Code of Federal Regulations, 2013 CFR
2013-01-01
... cotton. 28.303 Section 28.303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.303 Standards for length of staple for...
7 CFR 28.304 - Original representation of American Pima cotton staple lengths.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 2 2013-01-01 2013-01-01 false Original representation of American Pima cotton staple... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.304 Original representation of American...
7 CFR 28.304 - Original representation of American Pima cotton staple lengths.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 2 2012-01-01 2012-01-01 false Original representation of American Pima cotton staple... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.304 Original representation of American...
75 FR 70850 - Common Crop Insurance Regulations; Extra Long Staple Cotton Crop Provisions
Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-19
... Crop Insurance Regulations; Extra Long Staple Cotton Crop Provisions AGENCY: Federal Crop Insurance... Corporation (FCIC) proposes to amend the Common Crop Insurance Regulations, Extra Long Staple Cotton Crop Insurance Provisions to remove all references to the Daily Spot Cotton Quotation and replace the reference...
76 FR 32067 - Common Crop Insurance Regulations; Extra Long Staple Cotton Crop Provisions
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-03
... 0563-AC27 Common Crop Insurance Regulations; Extra Long Staple Cotton Crop Provisions AGENCY: Federal... (FCIC) finalizes amendments made to the Common Crop Insurance Regulations, Extra Long Staple Cotton Crop Insurance Provisions to remove all references to the Daily Spot Cotton Quotation and replace the references...
7 CFR 28.303 - Standards for length of staple for American upland cotton.
Code of Federal Regulations, 2011 CFR
2011-01-01
... cotton. 28.303 Section 28.303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.303 Standards for length of staple for...
78 FR 47214 - Common Crop Insurance Regulations; Extra Long Staple Cotton Crop Provisions
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-05
... Long Staple Cotton Crop Provisions AGENCY: Federal Crop Insurance Corporation, USDA. ACTION: Proposed... Insurance Regulations, Extra Long Staple (ELS) Cotton Crop Insurance Provisions to make the ELS Cotton Crop Insurance Provisions consistent with the Upland Cotton Crop Insurance Provisions and to allow a late...
7 CFR 28.304 - Original representation of American Pima cotton staple lengths.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 2 2014-01-01 2014-01-01 false Original representation of American Pima cotton staple... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.304 Original representation of American...
7 CFR 28.303 - Standards for length of staple for American upland cotton.
Code of Federal Regulations, 2014 CFR
2014-01-01
... cotton. 28.303 Section 28.303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.303 Standards for length of staple for...
7 CFR 28.304 - Original representation of American Pima cotton staple lengths.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 2 2011-01-01 2011-01-01 false Original representation of American Pima cotton staple... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.304 Original representation of American...
7 CFR 28.304 - Original representation of American Pima cotton staple lengths.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 2 2010-01-01 2010-01-01 false Original representation of American Pima cotton staple... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.304 Original representation of American...
7 CFR 28.303 - Standards for length of staple for American upland cotton.
Code of Federal Regulations, 2012 CFR
2012-01-01
... cotton. 28.303 Section 28.303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.303 Standards for length of staple for...
7 CFR 28.303 - Standards for length of staple for American upland cotton.
Code of Federal Regulations, 2010 CFR
2010-01-01
... cotton. 28.303 Section 28.303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.303 Standards for length of staple for...
21 CFR 878.4760 - Removable skin staple.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Removable skin staple. 878.4760 Section 878.4760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4760 Removable skin staple. (a...
21 CFR 878.4760 - Removable skin staple.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Removable skin staple. 878.4760 Section 878.4760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4760 Removable skin staple. (a...
21 CFR 878.4760 - Removable skin staple.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Removable skin staple. 878.4760 Section 878.4760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4760 Removable skin staple. (a...
21 CFR 878.4760 - Removable skin staple.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Removable skin staple. 878.4760 Section 878.4760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4760 Removable skin staple. (a...
Circular stapled anopexy for haemorrhoidal disease: results.
Lehur, P A; Gravié, J F; Meurette, G
2001-11-01
Stapled anopexy is a new approach for haemorrhoids requiring surgical treatment. This study reviews the available information concerning the present results of this procedure. Medline and hand search of the literature was conducted to identify available information on the procedure, with a special interest for the on-going or published randomized clinical trials. The advantages of the stapled approach of haemorrhoids were analyzed in the different areas of concern, including postoperative pain reduction, length of hospital stay and sick-leave, postoperative wound care and type and rate of complications. Continence status, symptom cure and patient satisfaction following stapled anopexy are also reported. Stapled anopexy is probably less painful than conventional haemorrhoidectomy. Other advantages in the short term result from this new approach. Long term efficacy of the procedure is still unknown.
Lim, C B B; Goldin, R D; Darzi, A; Hanna, G B
2008-08-01
Staples are made of titanium, which elicits minimal tissue reaction. The authors have encountered foreign body reaction associated with stapled human gastrointestinal anastomoses, although the literature has no reports of this. The aim of this study was to identify the refractile foreign materials causing this reaction. Histological sections were taken from 14 gastrointestinal specimens from patients with a history of a stapled anastomosis within the specimen excised. These were reviewed by light and polarization microscopy. Scanning electron microscopy and energy dispersive X-ray analysis were carried out on these sections, staples and stapler cartridges used for gastrointestinal surgery. Foreign bodies rich in fluorine were found in three patients, and those rich in carbon in 12. Other elements identified included oxygen, calcium, sodium, potassium, magnesium, aluminium and silicon. One specimen was found to contain titanium with no surrounding foreign body reaction. Stapler cartridges contained carbon, oxygen, fluorine, calcium, sodium, potassium, magnesium, aluminium, silicon and traces of titanium. Staples were composed of pure titanium with some fibrous material on the surface containing elements found in stapler cartridges. The presence of foreign body reaction was confirmed in stapled human gastrointestinal anastomoses. The source of refractile materials eliciting this reaction was the stapler cartridges. (c) 2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.
Rectal distensibility and symptoms after stapled and Milligan-Morgan operation for hemorrhoids.
Corsetti, Maura; De Nardi, Paola; Di Pietro, Salvatore; Passaretti, Sandro; Testoni, Pier Alberto; Staudacher, Carlo
2009-12-01
In a previous uncontrolled study, a reduction of rectal distensibility and volume thresholds for sensations have been related to the occurrence of fecal urgency and/or increased stool frequency after stapled hemorrhoidopexy. The aim of this study was to compare rectal symptoms and sensory-motor function after stapled hemorrhoidopexy and Milligan-Morgan hemorrhoidectomy. The clinical records of 12 (four women) and ten patients (four women) with third- and fourth-degree hemorrhoids, respectively, who underwent stapled hemorrhoidopexy or Milligan-Morgan's hemorrhoidectomy, were evaluated. One week before and 6 months after surgery, rectal motor and sensory response to distension was assessed by an electronic barostat, and bowel and rectal symptoms were recorded by means of a 7-day diary and Bristol Index scale and psychological symptoms with SCL-90 questionnaire. Rectal distensibility and volume thresholds for sensations were significantly lower after surgery (P < 0.02) in the stapled group. Increased stool frequency and/or fecal urgency arose in 41% of patients in the stapled group and associated with altered rectal distensibility. No difference within and between groups could be demonstrated in SCL-90 score. Rectal distensibility and volume thresholds for sensations decrease after stapled hemorrhoidopexy. Altered rectal distensibility was associated with rectal urgency and/or increased stool frequency.
Hydrocarbon double-stapling remedies the proteolytic instability of a lengthy peptide therapeutic
Bird, Gregory H.; Madani, Navid; Perry, Alisa F.; Princiotto, Amy M.; Supko, Jeffrey G.; He, Xiaoying; Gavathiotis, Evripidis; Sodroski, Joseph G.; Walensky, Loren D.
2010-01-01
The pharmacologic utility of lengthy peptides can be hindered by loss of bioactive structure and rapid proteolysis, which limits bioavailability. For example, enfuvirtide (Fuzeon, T20, DP178), a 36-amino acid peptide that inhibits human immunodeficiency virus type 1 (HIV-1) infection by effectively targeting the viral fusion apparatus, has been relegated to a salvage treatment option mostly due to poor in vivo stability and lack of oral bioavailability. To overcome the proteolytic shortcomings of long peptides as therapeutics, we examined the biophysical, biological, and pharmacologic impact of inserting all-hydrocarbon staples into an HIV-1 fusion inhibitor. We find that peptide double-stapling confers striking protease resistance that translates into markedly improved pharmacokinetic properties, including oral absorption. We determined that the hydrocarbon staples create a proteolytic shield by combining reinforcement of overall α-helical structure, which slows the kinetics of proteolysis, with complete blockade of peptide cleavage at constrained sites in the immediate vicinity of the staple. Importantly, double-stapling also optimizes the antiviral activity of HIV-1 fusion peptides and the antiproteolytic feature extends to other therapeutic peptide templates, such as the diabetes drug exenatide (Byetta). Thus, hydrocarbon double-stapling may unlock the therapeutic potential of natural bioactive polypeptides by transforming them into structurally fortified agents with enhanced bioavailability. PMID:20660316
Sjöberg, C; Ahnesjö, A
2013-06-01
Label fusion multi-atlas approaches for image segmentation can give better segmentation results than single atlas methods. We present a multi-atlas label fusion strategy based on probabilistic weighting of distance maps. Relationships between image similarities and segmentation similarities are estimated in a learning phase and used to derive fusion weights that are proportional to the probability for each atlas to improve the segmentation result. The method was tested using a leave-one-out strategy on a database of 21 pre-segmented prostate patients for different image registrations combined with different image similarity scorings. The probabilistic weighting yields results that are equal or better compared to both fusion with equal weights and results using the STAPLE algorithm. Results from the experiments demonstrate that label fusion by weighted distance maps is feasible, and that probabilistic weighted fusion improves segmentation quality more the stronger the individual atlas segmentation quality depends on the corresponding registered image similarity. The regions used for evaluation of the image similarity measures were found to be more important than the choice of similarity measure. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
26 CFR 1.269B-1 - Stapled foreign corporations.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 26 Internal Revenue 3 2013-04-01 2013-04-01 false Stapled foreign corporations. 1.269B-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Not Deductible § 1.269B-1 Stapled foreign corporations. (a) Treatment as a domestic corporation—(1) General rule. Except as otherwise provided, if a foreign corporation...
26 CFR 1.269B-1 - Stapled foreign corporations.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 26 Internal Revenue 3 2011-04-01 2011-04-01 false Stapled foreign corporations. 1.269B-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Not Deductible § 1.269B-1 Stapled foreign corporations. (a) Treatment as a domestic corporation—(1) General rule. Except as otherwise provided, if a foreign corporation...
26 CFR 1.269B-1 - Stapled foreign corporations.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 26 Internal Revenue 3 2014-04-01 2014-04-01 false Stapled foreign corporations. 1.269B-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Not Deductible § 1.269B-1 Stapled foreign corporations. (a) Treatment as a domestic corporation—(1) General rule. Except as otherwise provided, if a foreign corporation...
26 CFR 1.269B-1 - Stapled foreign corporations.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 26 Internal Revenue 3 2012-04-01 2012-04-01 false Stapled foreign corporations. 1.269B-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Not Deductible § 1.269B-1 Stapled foreign corporations. (a) Treatment as a domestic corporation—(1) General rule. Except as otherwise provided, if a foreign corporation...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-30
... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839, A-583-833] Certain Polyester... Commission (ITC) that revocation of the antidumping duty orders on certain polyester staple fiber from the... and the ITC instituted sunset reviews of the antidumping duty orders on polyester staple fiber from...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-12
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... International Trade Commission (``ITC'') that revocation of the antidumping duty order on certain polyester... antidumping duty order on certain polyester staple fiber from the PRC pursuant to section 751(c)(2) of the...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-28
... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 731-TA-825 and 826 (Second Review)] Polyester... Duty Orders on Polyester Staple Fiber From Korea and Taiwan AGENCY: United States International Trade... determine whether revocation of the antidumping duty orders on polyester staple fiber from Korea and Taiwan...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-04
... First Administrative Review of Certain Polyester Staple Fiber From the People's Republic of China: Final... the People's Republic of China (``PRC''). See First Administrative Review of Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Antidumping Duty Administrative Review, 75...
78 FR 70485 - Common Crop Insurance Regulations; Extra Long Staple Cotton Crop Provisions
Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-26
...-0002] RIN 0563-AC41 Common Crop Insurance Regulations; Extra Long Staple Cotton Crop Provisions AGENCY... Cotton Crop Insurance Provisions to make the Extra Long Staple (ELS) Cotton Crop Insurance Provisions consistent with the Upland Cotton Crop Insurance Provisions and to allow a late planting period. The intended...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-11
... System. Jianxin Fuda Chemical Fibre Factory. Comment 6: Correction of Name in Federal Register Notice... of Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Antidumping... duty order on certain polyester staple fiber (``PSF'') from the People's Republic of China (``PRC...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-06
... calls into question the reliability of this information. \\27\\ See Polyester Staple Fiber Final... Fiber From the People's Republic of China: Preliminary Results of the Antidumping Duty Administrative... duty order on certain polyester staple fiber from the People's Republic of China (``PRC'') for the...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-22
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber From... staple fiber (PSF) from Taiwan. The period of review (POR) is May 1, 2011, through April 30, 2012. The.... DATES: Effective Date: March 22, 2013. FOR FURTHER INFORMATION CONTACT: Bryan Hansen or Minoo Hatten, AD...
Novel Structures of Self-Associating Stapled Peptides
Bhattacharya, Shibani; Zhang, Hongtao; Cowburn, David; Debnath, Asim K.
2012-01-01
Hydrocarbon stapling of peptides is a powerful technique to transform linear peptides into cell-permeable helical structures that can bind to specific biological targets. In this study, we have used high resolution solution NMR techniques complemented by Dynamic Light Scattering to characterize extensively a family of hydrocarbon stapled peptides with known inhibitory activity against HIV-1 capsid assembly to evaluate the various factors that modulate activity. The helical peptides share a common binding motif but differ in charge, the length and position of the staple. An important outcome of the study was to show the peptides share a propensity to self-associate into organized polymeric structures mediated predominantly by hydrophobic interactions between the olefinic chain and the aromatic side-chains from the peptide. We have also investigated in detail the structural significance of the length and position of the staple, and of olefinic bond isomerization in stabilizing the helical conformation of the peptides as potential factors driving polymerization. This study presents the numerous challenges of designing biologically active stapled peptides and the conclusions have broad implications for optimizing a promising new class of compounds in drug discovery. PMID:22170623
Cheetham, M J; Cohen, C R G; Kamm, M A; Phillips, R K S
2003-04-01
Hemorrhoidectomy is the most effective long-term treatment for hemorrhoids. Although it is possible to perform hemorrhoidectomy as a day case with a high degree of patient satisfaction, patients take an average of 14 days off work after surgery. Stapled hemorrhoidectomy is believed to be less painful than conventional hemorrhoidectomy and should allow an earlier return to work. The aim of this study was to compare both the immediate and the long-term results of stapled hemorrhoidectomy with diathermy hemorrhoidectomy in patients with prolapsing internal hemorrhoids in an intended day-care setting. Thirty-one patients were randomly assigned to undergo diathermy hemorrhoidectomy (n = 16) or stapled hemorrhoidectomy performed with a purpose-designed endoluminal stapling device, PPH01T (n = 15). All operations were planned as day or short-stay cases. All patients received lactulose, commenced preoperatively, together with postoperative topical glyceryl trinitrate and oral metronidazole. Patients were assessed by structured interview to assess their symptoms before and after surgery, with an intended follow-up of six months. All patients completed a 10-cm visual analog pain scale daily for the first ten days after surgery. The total pain score (sum of all pain scores) was significantly higher in the diathermy group (50 (range, 9.8-79.9) vs. 19.6 (range, 1.3-89.5), P = 0.03). Patients took a median of 14 (range, 3-21) days off work after diathermy hemorrhoidectomy compared with 10 (range, 3-38) days for the patients undergoing stapled hemorrhoidectomy (P = 0.15). At long-term follow-up, three patients (all in the stapled group) developed new symptoms of fecal urgency and anal pain, and three patients required further surgery to remove symptomatic external hemorrhoids after stapled hemorrhoidectomy. Although stapled hemorrhoidectomy is less painful in the short term, this does not lead to a significantly earlier return to work, and some patients develop new symptoms at long-term follow-up.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-06
... Fiber From the People's Republic of China: Final Results of Expedited Sunset Review of the Antidumping... (``sunset'') review of the antidumping duty order on certain polyester staple fiber from the People's... Department finds that revocation of the antidumping duty order on certain polyester staple fiber from the PRC...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-30
... Receivership of 10006--First Integrity Bank, Staples, MN Notice Is Hereby Given that the Federal Deposit Insurance Corporation (``FDIC'') as Receiver for First Integrity Bank, Staples, MN (``the Receiver... Integrity Bank, Staples, MN on May 30, 2008. The liquidation of the receivership assets has been completed...
Polymorphic design of DNA origami structures through mechanical control of modular components.
Lee, Chanseok; Lee, Jae Young; Kim, Do-Nyun
2017-12-12
Scaffolded DNA origami enables the bottom-up fabrication of diverse DNA nanostructures by designing hundreds of staple strands, comprised of complementary sequences to the specific binding locations of a scaffold strand. Despite its exceptionally high design flexibility, poor reusability of staples has been one of the major hurdles to fabricate assorted DNA constructs in an effective way. Here we provide a rational module-based design approach to create distinct bent shapes with controllable geometries and flexibilities from a single, reference set of staples. By revising the staple connectivity within the desired module, we can control the location, stiffness, and included angle of hinges precisely, enabling the construction of dozens of single- or multiple-hinge structures with the replacement of staple strands up to 12.8% only. Our design approach, combined with computational shape prediction and analysis, can provide a versatile and cost-effective procedure in the design of DNA origami shapes with stiffness-tunable units.
Exploitation of the Ornithine Effect Enhances Characterization of Stapled and Cyclic Peptides
NASA Astrophysics Data System (ADS)
Crittenden, Christopher M.; Parker, W. Ryan; Jenner, Zachary B.; Bruns, Kerry A.; Akin, Lucas D.; McGee, William M.; Ciccimaro, Eugene; Brodbelt, Jennifer S.
2016-05-01
A method to facilitate the characterization of stapled or cyclic peptides is reported via an arginine-selective derivatization strategy coupled with MS/MS analysis. Arginine residues are converted to ornithine residues through a deguanidination reaction that installs a highly selectively cleavable site in peptides. Upon activation by CID or UVPD, the ornithine residue cyclizes to promote cleavage of the adjacent amide bond. This Arg-specific process offers a unique strategy for site-selective ring opening of stapled and cyclic peptides. Upon activation of each derivatized peptide, site-specific backbone cleavage at the ornithine residue results in two complementary products: the lactam ring-containing portion of the peptide and the amine-containing portion. The deguanidination process not only provides a specific marker site that initiates fragmentation of the peptide but also offers a means to unlock the staple and differentiate isobaric stapled peptides.
Generalizing Gillespie’s Direct Method to Enable Network-Free Simulations
Suderman, Ryan T.; Mitra, Eshan David; Lin, Yen Ting; ...
2018-03-28
Gillespie’s direct method for stochastic simulation of chemical kinetics is a staple of computational systems biology research. However, the algorithm requires explicit enumeration of all reactions and all chemical species that may arise in the system. In many cases, this is not feasible due to the combinatorial explosion of reactions and species in biological networks. Rule-based modeling frameworks provide a way to exactly represent networks containing such combinatorial complexity, and generalizations of Gillespie’s direct method have been developed as simulation engines for rule-based modeling languages. Here, we provide both a high-level description of the algorithms underlying the simulation engines, termedmore » network-free simulation algorithms, and how they have been applied in systems biology research. We also define a generic rule-based modeling framework and describe a number of technical details required for adapting Gillespie’s direct method for network-free simulation. Lastly, we briefly discuss potential avenues for advancing network-free simulation and the role they continue to play in modeling dynamical systems in biology.« less
Generalizing Gillespie’s Direct Method to Enable Network-Free Simulations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Suderman, Ryan T.; Mitra, Eshan David; Lin, Yen Ting
Gillespie’s direct method for stochastic simulation of chemical kinetics is a staple of computational systems biology research. However, the algorithm requires explicit enumeration of all reactions and all chemical species that may arise in the system. In many cases, this is not feasible due to the combinatorial explosion of reactions and species in biological networks. Rule-based modeling frameworks provide a way to exactly represent networks containing such combinatorial complexity, and generalizations of Gillespie’s direct method have been developed as simulation engines for rule-based modeling languages. Here, we provide both a high-level description of the algorithms underlying the simulation engines, termedmore » network-free simulation algorithms, and how they have been applied in systems biology research. We also define a generic rule-based modeling framework and describe a number of technical details required for adapting Gillespie’s direct method for network-free simulation. Lastly, we briefly discuss potential avenues for advancing network-free simulation and the role they continue to play in modeling dynamical systems in biology.« less
Skin closure using staples and nylon sutures: a comparison of results.
Stockley, I; Elson, R A
1987-03-01
A disposable skin stapler (Elite: Auto Suture UK Ltd) and Nylon vertical mattress sutures have been used for skin closure. The complications related to each method were evaluated in 129 wounds. There was a higher incidence of inflammation, discomfort on removal and spreading of the healing scar associated with staples. The only advantage of staples was speed of wound closure.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-15
... Fiber from the Republic of Korea: Preliminary Results of the 2008 - 2009 Antidumping Duty Administrative... antidumping duty order on certain polyester staple fiber from the Republic of Korea. The period of review is May 1, 2008, through April 30, 2009. This review covers imports of certain polyester staple fiber from...
Modelling DNA origami self-assembly at the domain level.
Dannenberg, Frits; Dunn, Katherine E; Bath, Jonathan; Kwiatkowska, Marta; Turberfield, Andrew J; Ouldridge, Thomas E
2015-10-28
We present a modelling framework, and basic model parameterization, for the study of DNA origami folding at the level of DNA domains. Our approach is explicitly kinetic and does not assume a specific folding pathway. The binding of each staple is associated with a free-energy change that depends on staple sequence, the possibility of coaxial stacking with neighbouring domains, and the entropic cost of constraining the scaffold by inserting staple crossovers. A rigorous thermodynamic model is difficult to implement as a result of the complex, multiply connected geometry of the scaffold: we present a solution to this problem for planar origami. Coaxial stacking of helices and entropic terms, particularly when loop closure exponents are taken to be larger than those for ideal chains, introduce interactions between staples. These cooperative interactions lead to the prediction of sharp assembly transitions with notable hysteresis that are consistent with experimental observations. We show that the model reproduces the experimentally observed consequences of reducing staple concentration, accelerated cooling, and absent staples. We also present a simpler methodology that gives consistent results and can be used to study a wider range of systems including non-planar origami.
Modelling DNA origami self-assembly at the domain level
NASA Astrophysics Data System (ADS)
Dannenberg, Frits; Dunn, Katherine E.; Bath, Jonathan; Kwiatkowska, Marta; Turberfield, Andrew J.; Ouldridge, Thomas E.
2015-10-01
We present a modelling framework, and basic model parameterization, for the study of DNA origami folding at the level of DNA domains. Our approach is explicitly kinetic and does not assume a specific folding pathway. The binding of each staple is associated with a free-energy change that depends on staple sequence, the possibility of coaxial stacking with neighbouring domains, and the entropic cost of constraining the scaffold by inserting staple crossovers. A rigorous thermodynamic model is difficult to implement as a result of the complex, multiply connected geometry of the scaffold: we present a solution to this problem for planar origami. Coaxial stacking of helices and entropic terms, particularly when loop closure exponents are taken to be larger than those for ideal chains, introduce interactions between staples. These cooperative interactions lead to the prediction of sharp assembly transitions with notable hysteresis that are consistent with experimental observations. We show that the model reproduces the experimentally observed consequences of reducing staple concentration, accelerated cooling, and absent staples. We also present a simpler methodology that gives consistent results and can be used to study a wider range of systems including non-planar origami.
Hu, Zhi-Geng; Tan, Rong-Shao; Jin, Di; Li, Wei; Zhou, Xiao-Yan
2014-12-01
A low glycemic index (GI) diet is beneficial for glucose control in patients with diabetes mellitus. This study aimed to investigate the influence of a low-GI diet on postprandial glucose levels in women with gestational diabetes mellitus (GDM). Pregnant women with GDM were randomized to receive a normal diabetic control diet or a low-GI staple diet for 5 days. A low-GI staple food was used to replace rice in lunch and dinner for the low-GI staple diet group, whereas the total energy and carbohydrate levels remained equal in both groups. Fasting and postprandial glucose levels were determined daily. A total of 140 pregnant women with GDM were included in the study, including 66 in the low-GI staple diet group and 74 in the normal diabetic diet control group. No differences existed in baseline characteristics between the 2 groups (all P > 0.05). After dietary intervention, glucose levels were significantly reduced in the low-GI staple diet group (all P < 0.01) and the control group (all P < 0.008). Postintervention glucose values after breakfast, lunch, and dinner were significantly reduced in the treatment group compared with those in the control group (all P < 0.05). The percentage changes from baseline of all glucose values were significantly greater in the treatment group than in the control group (all P < 0.05). A low-GI staple diet significantly reduces postprandial glucose levels in women with GDM.
Terterov, Dimitry; Leung, Philemon Ho-Yan; Twells, Laurie K.; Gregory, Deborah M.; Smith, Chris; Boone, Darrell; Pace, David
2017-01-01
Background Although laparoscopic sleeve gastrectomy (LSG) has been shown to be a safe and effective treatment for severe obesity (body mass index ≥ 35), staple line leaks remain a major complication and account for a substantial portion of the procedure’s morbidity and mortality. Many centres performing LSG routinely obtain contrast studies on postoperative day 1 for early detection of staple line leaks. We examined the usefulness of Gastrografin swallow as an early detection test for staple line leaks on postoperative day 1 after LSG as well as the associated costs. Methods We conducted a retrospective review of a prospectively collected database that included 200 patients who underwent LSG for severe obesity between 2011 and 2014. Primary outcome measures were the incidence of staple line leaks and the results of Gastrografin swallow tests. We obtained imaging costs from appropriate hospital departments. Results Gastrografin swallow was obtained on postoperative day 1 for all 200 patients who underwent LSG. Three patients (1.5%) were found to have staple line leaks. Gastrograffin swallows yielded 1 true positive result and 2 false negatives. The false negatives were subsequently diagnosed on computed tomography (CT) scan. The sensitivity of Gastrografin swallow in this study was 33%. For 200 patients, the total direct cost of the Gastrografin swallows was $35 000. Conclusion The use of routine upper gastrointestinal contrast studies for early detection of staple line leaks has low sensitivity and is costly. We recommend selective use of CT instead. PMID:28742012
Terterov, Dimitry; Leung, Philemon Ho-Yan; Twells, Laurie K; Gregory, Deborah M; Smith, Chris; Boone, Darrell; Pace, David
2017-09-01
Although laparoscopic sleeve gastrectomy (LSG) has been shown to be a safe and effective treatment for severe obesity (body mass index ≥ 35), staple line leaks remain a major complication and account for a substantial portion of the procedure's morbidity and mortality. Many centres performing LSG routinely obtain contrast studies on postoperative day 1 for early detection of staple line leaks. We examined the usefulness of Gastrografin swallow as an early detection test for staple line leaks on postoperative day 1 after LSG as well as the associated costs. We conducted a retrospective review of a prospectively collected database that included 200 patients who underwent LSG for severe obesity between 2011 and 2014. Primary outcome measures were the incidence of staple line leaks and the results of Gastrografin swallow tests. We obtained imaging costs from appropriate hospital departments. Gastrografin swallow was obtained on postoperative day 1 for all 200 patients who underwent LSG. Three patients (1.5%) were found to have staple line leaks. Gastrograffin swallows yielded 1 true positive result and 2 false negatives. The false negatives were subsequently diagnosed on computed tomography (CT) scan. The sensitivity of Gastrografin swallow in this study was 33%. For 200 patients, the total direct cost of the Gastrografin swallows was $35 000. The use of routine upper gastrointestinal contrast studies for early detection of staple line leaks has low sensitivity and is costly. We recommend selective use of CT instead.
Grotenhuis, Brechtje A; Nonner, Joost; de Graaf, Eelco J R; Doornebosch, Pascal G
2017-11-02
Stapled anopexy is a safe technique for the treatment of hemorrhoids but carries a higher risk of recurrence, which might be caused due to the limited volume of resected tissue. In this study, we investigated the introduction of a high-volume circular stapling device; in particular whether an increased amount of resected tissue could affect patients' short-term postoperative outcome. Between 2011 and 2015, stapled anopexy was performed for hemorrhoids and/or anal prolapse in 141 patients (n = 25 conventional PPH-3©-stapler versus n = 116 high-volume CHEX©-stapler). In this prospectively collected dataset, operation details and short-term postoperative outcome were compared. With the high-volume stapler, a significantly higher amount of tissue was resected: 9.8 g (range 6.2-11.4) vs. 6.4 g (range 4.9-8.8) with the conventional stapler, p < 0.01. Postoperative short-term outcome did not differ in terms of readmission and complication rates. In all 5 patients who underwent a redo operation for residual hemorrhoids or prolapse, the high-volume stapler was used in the primary operation. A high-volume stapling device for stapled anopexy was introduced safely with a significantly higher amount of resected tissue without a worse short-term outcome. However, it remains unclear whether higher stapling volumes may lead to improved long-term outcome with less reinterventions. © 2017 S. Karger AG, Basel.
Prospects for Genomic Selection in Cassava Breeding.
Wolfe, Marnin D; Del Carpio, Dunia Pino; Alabi, Olumide; Ezenwaka, Lydia C; Ikeogu, Ugochukwu N; Kayondo, Ismail S; Lozano, Roberto; Okeke, Uche G; Ozimati, Alfred A; Williams, Esuma; Egesi, Chiedozie; Kawuki, Robert S; Kulakow, Peter; Rabbi, Ismail Y; Jannink, Jean-Luc
2017-11-01
Cassava ( Crantz) is a clonally propagated staple food crop in the tropics. Genomic selection (GS) has been implemented at three breeding institutions in Africa to reduce cycle times. Initial studies provided promising estimates of predictive abilities. Here, we expand on previous analyses by assessing the accuracy of seven prediction models for seven traits in three prediction scenarios: cross-validation within populations, cross-population prediction and cross-generation prediction. We also evaluated the impact of increasing the training population (TP) size by phenotyping progenies selected either at random or with a genetic algorithm. Cross-validation results were mostly consistent across programs, with nonadditive models predicting of 10% better on average. Cross-population accuracy was generally low (mean = 0.18) but prediction of cassava mosaic disease increased up to 57% in one Nigerian population when data from another related population were combined. Accuracy across generations was poorer than within-generation accuracy, as expected, but accuracy for dry matter content and mosaic disease severity should be sufficient for rapid-cycling GS. Selection of a prediction model made some difference across generations, but increasing TP size was more important. With a genetic algorithm, selection of one-third of progeny could achieve an accuracy equivalent to phenotyping all progeny. We are in the early stages of GS for this crop but the results are promising for some traits. General guidelines that are emerging are that TPs need to continue to grow but phenotyping can be done on a cleverly selected subset of individuals, reducing the overall phenotyping burden. Copyright © 2017 Crop Science Society of America.
[Errors and dangers in use of the surgical stapler in lung surgery].
Junginger, T; Walgenbach, S
1989-01-01
The staple closure of the bronchus, like the manual technique, depends on some essential prerequisites: vascular supply, the length and thickness of the bronchial stump, the resection line, the type of stapler and the size of staples used. GIA 55 or 90 instruments allow safe and simple closure of lung parenchyma. Familiarity with the stapling technique is essential for success.
Blumenthal, Scott A.; Chritz, Kendra L.; Rothman, Jessica M.; Cerling, Thure E.
2012-01-01
We use stable isotope ratios in feces of wild mountain gorillas (Gorilla beringei) to test the hypothesis that diet shifts within a single year, as measured by dry mass intake, can be recovered. Isotopic separation of staple foods indicates that intraannual changes in the isotopic composition of feces reflect shifts in diet. Fruits are isotopically distinct compared with other staple foods, and peaks in fecal δ13C values are interpreted as periods of increased fruit feeding. Bayesian mixing model results demonstrate that, although the timing of these diet shifts match observational data, the modeled increase in proportional fruit feeding does not capture the full shift. Variation in the isotopic and nutritional composition of gorilla foods is largely independent, highlighting the difficulty for estimating nutritional intake with stable isotopes. Our results demonstrate the potential value of fecal sampling for quantifying short-term, intraindividual dietary variability in primates and other animals with high temporal resolution even when the diet is composed of C3 plants. PMID:23236160
Management of a failed mandibular staple implant: a clinical report.
Ettinger, Ronald L; Fakhry, Ali
2010-12-01
A 48-year-old woman sought treatment because her staple implant-retained overdenture was no longer retentive, and the denture was worn over the abutments. After unsuccessfully attempting to move the retentive nuts along the transosseous posts of the staple implant, the posts were cut off at the level of the bone. Two endosseous implants were placed around the staple implant, and a new implant-retained overdenture was fabricated and inserted using ball attachments for retention. This article describes the treatment for this patient, who has been wearing the new dentures successfully for the past 4 years. Copyright © 2010 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.
Preparation and Characterization of Nitinol Bone Staples for Cranio-Maxillofacial Surgery
NASA Astrophysics Data System (ADS)
Lekston, Z.; Stróż, D.; Jędrusik-Pawłowska, M.
2012-12-01
The aim of this work was to form NiTi and TiNiCo body temperature activated and superelastic staples for clinical joining of mandible and face bone fractures. The alloys were obtained by VIM technique. Hot and cold processing was applied to obtain wires of required diameters. The martensitic transformation was studied by DSC, XRD, and TEM. The shape memory effects were measured by a bend and free recovery ASTM F2082-06 test. The superelasticity was recorded in the tension stress-strain and by the three-point bending cycles in an instrument equipped with a Hottinger force transducer and LVDT. Excellent superelastic behavior of TiNiCo wires was obtained after cold working and annealing at 400-500 °C. The body temperature activated shape memory staples were applied for fixation of mandibular condyle fractures. In experiments on the skull models, fixation of the facial fractures by using shape memory and superelastic staples were compared. The superelastic staples were used in osteosynthesis of zygomatico-maxillo-orbital fractures.
Stapled Golgi cisternae remain in place as cargo passes through the stack
Lavieu, Gregory; Zheng, Hong; Rothman, James E
2013-01-01
We have designed a membrane ‘staple’, which consists of membrane-anchored repeats of the trans-aggregating FM domain that face the lumen of the secretory pathway. In the presence of the disaggregating drug these proteins transit the secretory pathway. When the drug is removed these proteins form electron-dense plaques which we term staples. Unexpectedly, when initially positioned within the cis-Golgi, staples remained at the cis face of the Golgi even after many hours. By contrast, soluble FM-aggregates transited the Golgi. Staples and soluble aggregates placed in cis-Golgi cisternae therefore have different fates. Whereas the membrane staples are located in the flattened, stacked central regions of the cisternae, the soluble aggregates are in the dilated rims. This suggests that while the cisternae are static on the time scale of protein traffic, the dilated rims are mobile and progress in the cis → trans direction via a mechanism that we term ‘Rim Progression’. DOI: http://dx.doi.org/10.7554/eLife.00558.001 PMID:23755362
A randomized study comparing skin closure in cesarean sections: staples vs subcuticular sutures.
Rousseau, Julie-Anne; Girard, Karine; Turcot-Lemay, Lucile; Thomas, Nancy
2009-03-01
We sought to compare postoperative pain according to the skin closure method (subcuticular sutures vs staples) after an elective term cesarean section. A randomized controlled trial of 101 women was performed. Women were randomly assigned to subcuticular sutures or staples. Operative technique and postoperative analgesia were standardized. Stratification was used for primary vs repeat cesareans. Analog pain and satisfaction scales ranging from 0-10 were completed at postoperative days 1 and 3, and at 6 weeks postoperatively. A digital photograph of the incision was taken at 6 weeks postoperatively and evaluated by 3 independent blinded observers. Pain at 6 weeks postoperatively was significantly less in the staple group (0.17 vs 0.51; P = .04). Operative time was shorter in that group (24.6 vs 32.9 minutes; P < .0001). No difference was noted for incision appearance and women's satisfaction. Staples are the method of choice for skin closure for elective term cesareans in our population.
Chandramohan, S M; Gajbhiye, Raj Narenda; Agwarwal, Anil; Creedon, Erin; Schwiers, Michael L; Waggoner, Jason R; Tatla, Daljit
2013-08-01
Although stapling is an alternative to hand-suturing in gastrointestinal surgery, recent trials specifically designed to evaluate differences between the two in surgery time, anastomosis time, and return to bowel activity are lacking. This trial compared the outcomes of the two in subjects undergoing open gastrointestinal surgery. Adult subjects undergoing emergency or elective surgery requiring a single gastric, small, or large bowel anastomosis were enrolled into this open-label, prospective, randomized, interventional, parallel, multicenter, controlled trial. Randomization was assigned in a 1:1 ratio between the hand-sutured group (n = 138) and the stapled group (n = 142). Anastomosis time, surgery time, and time to bowel activity were collected and compared as primary endpoints. A total of 280 subjects were enrolled from April 2009 to September 2010. Only the time of anastomosis was significantly different between the two arms: 17.6 ± 1.90 min (stapled) and 20.6 ± 1.90 min (hand-sutured). This difference was deemed not clinically or economically meaningful. Safety outcomes and other secondary endpoints were similar between the two arms. Mechanical stapling is faster than hand-suturing for the construction of gastrointestinal anastomoses. Apart from this, stapling and hand-suturing are similar with respect to the outcomes measured in this trial.
Long-term Evaluation of a Modified Double Staple Technique for Low Anterior Resection.
Illuminati, G; Carboni, F; Ceccanei, G; Pacilè, M A; Pizzardi, G; Palumbo, P; Vietri, F
2014-01-01
When performing low anterior resection for rectal cancer with the double staple technique, -closing the rectum with a linear stapler in the abdomen can be challenging, especially when dealing with a narrow pelvis. For such instances we proposed to modify this technique by pulling the rectal stump through the anus, doing an extra-anal resection of the tumor and linear suture of the rectal stump, before performing a standard, stapled colorectal anastomosis. The purpose of this study was to assess the adequacy of this modification of the double staple technique. Retrospective review of 108 patients undergoing a stapled, low colorectal or coloanal anastomosis, after -eversion, extra-anal resection of the tumor and linear closure of the rectal stump for colorectal cancer, from January 1990 to December 2012. Operative mortality was 0.9%. Fourteen patients (13%) presented early, surgery-related complications -consisting of 7 anastomotic leaks, 5 wound infections, 1 ureteral lesion, and 1 peristomal abscess. Late complications related to surgery included 5 incisional hernias (4.6%), 4 anastomotic strictures (3.7%), 4 neurogenic bladders (3.7%) and 2 fecal incontinences (1.8%). The incidence of local disease recurrence was 10%. Surgical and oncological results validate the proposed modification of the double staple technique, when facing difficulties in suturing the rectum from the abdomen. Copyright© Acta Chirurgica Belgica.
Skin closure using staples and nylon sutures: a comparison of results.
Stockley, I.; Elson, R. A.
1987-01-01
A disposable skin stapler (Elite: Auto Suture UK Ltd) and Nylon vertical mattress sutures have been used for skin closure. The complications related to each method were evaluated in 129 wounds. There was a higher incidence of inflammation, discomfort on removal and spreading of the healing scar associated with staples. The only advantage of staples was speed of wound closure. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:3566131
Deeley, M A; Chen, A; Datteri, R; Noble, J; Cmelak, A; Donnelly, E; Malcolm, A; Moretti, L; Jaboin, J; Niermann, K; Yang, Eddy S; Yu, David S; Yei, F; Koyama, T; Ding, G X; Dawant, B M
2011-01-01
The purpose of this work was to characterize expert variation in segmentation of intracranial structures pertinent to radiation therapy, and to assess a registration-driven atlas-based segmentation algorithm in that context. Eight experts were recruited to segment the brainstem, optic chiasm, optic nerves, and eyes, of 20 patients who underwent therapy for large space-occupying tumors. Performance variability was assessed through three geometric measures: volume, Dice similarity coefficient, and Euclidean distance. In addition, two simulated ground truth segmentations were calculated via the simultaneous truth and performance level estimation (STAPLE) algorithm and a novel application of probability maps. The experts and automatic system were found to generate structures of similar volume, though the experts exhibited higher variation with respect to tubular structures. No difference was found between the mean Dice coefficient (DSC) of the automatic and expert delineations as a group at a 5% significance level over all cases and organs. The larger structures of the brainstem and eyes exhibited mean DSC of approximately 0.8–0.9, whereas the tubular chiasm and nerves were lower, approximately 0.4–0.5. Similarly low DSC have been reported previously without the context of several experts and patient volumes. This study, however, provides evidence that experts are similarly challenged. The average maximum distances (maximum inside, maximum outside) from a simulated ground truth ranged from (−4.3, +5.4) mm for the automatic system to (−3.9, +7.5) mm for the experts considered as a group. Over all the structures in a rank of true positive rates at a 2 mm threshold from the simulated ground truth, the automatic system ranked second of the nine raters. This work underscores the need for large scale studies utilizing statistically robust numbers of patients and experts in evaluating quality of automatic algorithms. PMID:21725140
Simillis, C; Thoukididou, S N; Slesser, A A P; Rasheed, S; Tan, E; Tekkis, P P
2015-12-01
The aim was to compare the clinical outcomes and effectiveness of surgical treatments for haemorrhoids. Randomized clinical trials were identified by means of a systematic review. A Bayesian network meta-analysis was performed using the Markov chain Monte Carlo method in WinBUGS. Ninety-eight trials were included with 7827 participants and 11 surgical treatments for grade III and IV haemorrhoids. Open, closed and radiofrequency haemorrhoidectomies resulted in significantly more postoperative complications than transanal haemorrhoidal dearterialization (THD), LigaSure™ and Harmonic® haemorrhoidectomies. THD had significantly less postoperative bleeding than open and stapled procedures, and resulted in significantly fewer emergency reoperations than open, closed, stapled and LigaSure™ haemorrhoidectomies. Open and closed haemorrhoidectomies resulted in more pain on postoperative day 1 than stapled, THD, LigaSure™ and Harmonic® procedures. After stapled, LigaSure™ and Harmonic® haemorrhoidectomies patients resumed normal daily activities earlier than after open and closed procedures. THD provided the earliest time to first bowel movement. The stapled and THD groups had significantly higher haemorrhoid recurrence rates than the open, closed and LigaSure™ groups. Recurrence of haemorrhoidal symptoms was more common after stapled haemorrhoidectomy than after open and LigaSure™ operations. No significant difference was identified between treatments for anal stenosis, incontinence and perianal skin tags. Open and closed haemorrhoidectomies resulted in more postoperative complications and slower recovery, but fewer haemorrhoid recurrences. THD and stapled haemorrhoidectomies were associated with decreased postoperative pain and faster recovery, but higher recurrence rates. The advantages and disadvantages of each surgical treatment should be discussed with the patient before surgery to allow an informed decision to be made. © 2015 BJS Society Ltd Published by John Wiley & Sons Ltd.
A Circular Surgical Stapler Designed to Anastomose Aorta and Dacron Tube Graft
2013-01-01
Background: A circular aortic stapler has been developed to anastomose the open end of the aorta to a size-matched Dacron tube graft in one quick motion and without having to pull sutures through the aortic wall. Methods: A prototype was developed, and its design and function were tested in bench experiments and compared with hand-sewn anastomosis. The basic design of the stapler is a central rod (anvil) surrounded by 10 stapling limbs, which can be closed over the anvil in a full circle, with staples extruded by turning a knob at the back. To test its function, a Dacron tube graft was inserted in the middle of a length of bovine aorta. One side was anastomosed with the stapler and the other hand-sewn in each of 10 experiments. Bovine blood was infused under increasing pressure. Results: It took considerably less time to complete the stapled anastomosis than the hand-sewn side (3 minutes, 46 seconds versus 15 minutes, 42 seconds). Initial leak occurred at low pressures on the hand-sewn side (mean pressure 40 mm Hg) compared with the stapled side (mean pressure 70 mm Hg). In 7 of 10 experiments, the leak became too brisk on the hand-sewn side to sustain pressure, compared with 3 of 10 with stapled anastomoses. The stapling device performed well in all cases except when the bovine aorta was too thick for the staples (two cases) or when there was a missed branch at the anastomotic site (one case). Conclusions: These experiments validate the concept and the design of this aortic stapler. There are some limitations in the current design, which will need to be modified before its use in live animals or clinically. PMID:26798678
George, R; Garcia, A L; Edwards, C A
2015-06-01
The glycaemic responses of staples differ when eaten as mixed meals. We determined the glycaemic responses and glycaemic index (GI) values for common South Asian carbohydrate rich foods and the effect of adding curried chicken to them as mixed meals. The GI and glycaemic response to staples (basmati rice, pilau rice and chapatti) and mixed meals (pilau rice with chicken curry and chapatti with chicken curry) were measured in healthy volunteers. Paired comparisons in each subject were carried out for staples and their equivalent mixed meals (n = 9). GI values for the mixed meals were significantly lower than the staples alone (41 and 60 for pilau rice with chicken curry and pilau rice alone, P = 0.001; 45 and 68 for chapatti with chicken curry and chapatti alone, P = 0.004). Both, pilau rice and chapatti with chicken curry had a significantly lower glycaemic response than their equivalent staples alone: incremental area under the blood glucose response curves (IAUC) 111.9 mmol min(-1 ) L(-1) for pilau rice with curry versus 162.4 mmol min(-1 ) L(-1) for pilau rice alone (P = 0.001) and IAUC 110.1 mmol min(-1 ) L(-1) for chapatti with chicken curry versus 183.6 mmol min(-1 ) L(-1) for chapatti alone (P = 0.002). Adding fat and protein-containing curries as part of a mixed meal to carbohydrate rich staple foods reduced glycaemic responses, and also changed the GI category. © 2014 The British Dietetic Association Ltd.
Raza, Syed T
2013-06-01
A circular aortic stapler has been developed to anastomose the open end of the aorta to a size-matched Dacron tube graft in one quick motion and without having to pull sutures through the aortic wall. A prototype was developed, and its design and function were tested in bench experiments and compared with hand-sewn anastomosis. The basic design of the stapler is a central rod (anvil) surrounded by 10 stapling limbs, which can be closed over the anvil in a full circle, with staples extruded by turning a knob at the back. To test its function, a Dacron tube graft was inserted in the middle of a length of bovine aorta. One side was anastomosed with the stapler and the other hand-sewn in each of 10 experiments. Bovine blood was infused under increasing pressure. It took considerably less time to complete the stapled anastomosis than the hand-sewn side (3 minutes, 46 seconds versus 15 minutes, 42 seconds). Initial leak occurred at low pressures on the hand-sewn side (mean pressure 40 mm Hg) compared with the stapled side (mean pressure 70 mm Hg). In 7 of 10 experiments, the leak became too brisk on the hand-sewn side to sustain pressure, compared with 3 of 10 with stapled anastomoses. The stapling device performed well in all cases except when the bovine aorta was too thick for the staples (two cases) or when there was a missed branch at the anastomotic site (one case). These experiments validate the concept and the design of this aortic stapler. There are some limitations in the current design, which will need to be modified before its use in live animals or clinically.
2013-04-15
Kentwool recombed the wool top ( wool is first combed during the production of wool top); a second combing process is an optional step sometimes used in...RESISTANT COMBAT UNIFORM FABRICS MADE FROM LONG STAPLE WOOL AND ARAMID BLEND YARN by Parvez Mehta* Mitchell Driggers* and Carole...SUBTITLE DEVELOPMENT OF FLAME RESISTANT COMBAT UNIFORM FABRICS MADE FROM LONG STAPLE WOOL AND ARAMID BLEND YARN 5a. CONTRACT NUMBER W911QY-11
Belandria, Gerardo A.; Pavletic, Michael M.; Boulay, James P.; Penninck, Dominique G.; Schwarz, Leslie A.
2009-01-01
Surgical stapling equipment was used to create a gastropexy in 20 dogs undergoing emergency surgery for gastric dilatation and volvulus (GDV). The technique involved creation of a tunnel between the seromuscular layer and the submucosa of the pyloric antrum, and a matching tunnel beneath the right m. transversus abdominis. The arms of a gastrointestinal anastomosis stapling device were introduced into the tunnels, and the device was fired to create the gastropexy. One dog died of systemic sequelae of GDV during the early postoperative period. None of the remaining 19 dogs developed a recurrence of GDV during follow-up periods ranging from 5 to 43 months. In 11 dogs, the integrity of the gastropexy was evaluated by abdominal ultrasonography and either negative contrast gastrography or double contrast gastrography; in these dogs, the radiographic and/or the ultrasonographic findings were suggestive of an intact gastropexy. There were no complications involving the gastropexy staple line. The results of this study indicate that an effective and consistent permanent gastropexy can be created, using surgical stapling equipment. PMID:19794869
Belandria, Gerardo A; Pavletic, Michael M; Boulay, James P; Penninck, Dominique G; Schwarz, Leslie A
2009-07-01
Surgical stapling equipment was used to create a gastropexy in 20 dogs undergoing emergency surgery for gastric dilatation and volvulus (GDV). The technique involved creation of a tunnel between the seromuscular layer and the submucosa of the pyloric antrum, and a matching tunnel beneath the right m. transversus abdominis. The arms of a gastrointestinal anastomosis stapling device were introduced into the tunnels, and the device was fired to create the gastropexy. One dog died of systemic sequelae of GDV during the early postoperative period. None of the remaining 19 dogs developed a recurrence of GDV during follow-up periods ranging from 5 to 43 months. In 11 dogs, the integrity of the gastropexy was evaluated by abdominal ultrasonography and either negative contrast gastrography or double contrast gastrography; in these dogs, the radiographic and/or the ultrasonographic findings were suggestive of an intact gastropexy. There were no complications involving the gastropexy staple line. The results of this study indicate that an effective and consistent permanent gastropexy can be created, using surgical stapling equipment.
Stapler-assisted closure in total laryngectomy.
Anand, Akash G
2013-01-01
The total laryngectomy is a surgical procedure that requires technically sound reconstruction in order to preserve a patient's swallowing function. Traditionally, a handsewn technique has been utilized to accomplish this endeavor. Recent applications of surgical stapling devices have been noted in an attempt to circumvent the need for handsewn reconstruction. This paper documents the application of a surgical stapling device in reconstructing a total laryngectomy defect. A brief review of the literature is provided to compare the differences between handsewn techniques and stapling techniques.
Nam, Gimoon; Hisette, Marie Laure; Sun, Yuting Liang; Gisler, Thomas; Johner, Albert; Thalmann, Fabrice; Schröder, André Pierre; Marques, Carlos Manuel; Lee, Nam-Kyung
2010-08-20
Stained end-grafted DNA molecules about 20 μm long are scraped away and stretched out by the spreading front of a bioadhesive vesicle. Tethered biotin ligands bind the vesicle bilayer to a streptavidin substrate, stapling the DNAs into frozen confinement paths. Image analysis of the stapled DNA gives access, within optical resolution, to the local stretching values of individual DNA molecules swept by the spreading front, and provides evidence of self-entanglements.
Ngo, Duc Minh; Hough, Rupert Lloyd; Le, Thi Thuy; Nyberg, Ylva; Le, Bach Mai; Nguyen, Cong Vinh; Nguyen, Manh Khai; Oborn, Ingrid
2012-02-01
This study estimates the dietary exposure to cadmium (Cd), and associated potential health risks, for individuals living and working in a metal recycling community (n=132) in Vietnam in comparison to an agricultural (reference) community (n=130). Individual-level exposure to Cd was estimated through analysis of staple foodstuffs combined with information from a food frequency questionnaire. Individual-level exposure estimates were compared with published 'safe' doses to derive a Hazard Quotient (HQ) for each member of the study population. Looking at the populations as a whole, there were no significant differences in the diets of the two villages. However, significantly more rice was consumed by working age adults (18-60 years) in the recycling village compared to the reference village (p<0.001). Rice was the main staple food with individuals consuming 461±162g/d, followed by water spinach (103±51kg/d). Concentrations of Cd in the studied foodstuffs were elevated in the metal recycling village. Values of HQ exceeded unity for 87% of adult participants of the metal recycling community (39% had a HQ>3), while 20% of adult participants from the reference village had an HQ>1. We found an elevated health risk from dietary exposure to Cd in the metal recycling village compared to the reference community. WHO standard of 0.4mg Cd/kg rice may not be protective where people consume large amounts of rice/have relatively low body weight. Copyright © 2011 Elsevier B.V. All rights reserved.
Kuroki, Lindsay M; Mullen, Mary M; Massad, L Stewart; Wu, Ningying; Liu, Jingxia; Mutch, David G; Powell, Matthew A; Hagemann, Andrea R; Thaker, Premal H; McCourt, Carolyn K; Novetsky, Akiva P
2017-07-01
To compare wound complication rates after skin closure with staples and subcuticular suture in obese gynecology patients undergoing laparotomy through a midline vertical incision. In this randomized controlled trial, women with body mass indexes (BMIs) of 30 or greater undergoing surgery by a gynecologic oncologist through a midline vertical incision were randomized to skin closure with staples or subcuticular 4-0 monofilament suture. The primary outcome was the rate of wound complication, defined as the presence of a wound breakdown, or infection, within 8 weeks postoperatively. Secondary outcomes included operative time, Stony Brook scar cosmetic score, and patient satisfaction. A sample size of 162 was planned to detect a 50% reduction in wound complications. At planned interim review (n=82), there was no significant difference in primary outcome. Between 2013 and 2016, 163 women were analyzed, including 84 who received staples and 79 suture. Women who received staples were older (mean age 59 compared with 57 years), had lower mean BMI (37.3 compared with 38.9), and fewer benign indications for surgery (22 compared with 27). There were no differences in wound complication rates between staple compared with suture skin closure (28 [33%] compared with 25 [32%], relative risk 1.05, 95% confidence interval [CI] 0.68-1.64). Women with staples reported worse median cosmetic scores (four of five compared with five of five, P<.001), darker scar color (37 [49%] compared with 13 [18%], relative risk 2.69, 95% CI 1.57-4.63), and more skin marks (30 [40%] compared with three [4%], relative risk 9.47, 95% CI 3.02-29.65) compared with women with suture closure. There was no group difference regarding satisfaction with their scar. Stepwise multivariate analysis revealed BMI (odds ratio [OR] 1.13, 95% CI 1.07-1.20), maximum postoperative glucose (OR 1.01, 95% CI 1.00-1.01), and cigarette smoking (OR 4.96, 95% CI 1.32-18.71) were correlates of wound complication. Closure of midline vertical skin incisions with subcuticular suture does not reduce surgical site wound complications compared with staples in obese gynecology patients. ClinicalTrials.gov, NCT01977612.
Multi-Complementary Model for Long-Term Tracking
Zhang, Deng; Zhang, Junchang; Xia, Chenyang
2018-01-01
In recent years, video target tracking algorithms have been widely used. However, many tracking algorithms do not achieve satisfactory performance, especially when dealing with problems such as object occlusions, background clutters, motion blur, low illumination color images, and sudden illumination changes in real scenes. In this paper, we incorporate an object model based on contour information into a Staple tracker that combines the correlation filter model and color model to greatly improve the tracking robustness. Since each model is responsible for tracking specific features, the three complementary models combine for more robust tracking. In addition, we propose an efficient object detection model with contour and color histogram features, which has good detection performance and better detection efficiency compared to the traditional target detection algorithm. Finally, we optimize the traditional scale calculation, which greatly improves the tracking execution speed. We evaluate our tracker on the Object Tracking Benchmarks 2013 (OTB-13) and Object Tracking Benchmarks 2015 (OTB-15) benchmark datasets. With the OTB-13 benchmark datasets, our algorithm is improved by 4.8%, 9.6%, and 10.9% on the success plots of OPE, TRE and SRE, respectively, in contrast to another classic LCT (Long-term Correlation Tracking) algorithm. On the OTB-15 benchmark datasets, when compared with the LCT algorithm, our algorithm achieves 10.4%, 12.5%, and 16.1% improvement on the success plots of OPE, TRE, and SRE, respectively. At the same time, it needs to be emphasized that, due to the high computational efficiency of the color model and the object detection model using efficient data structures, and the speed advantage of the correlation filters, our tracking algorithm could still achieve good tracking speed. PMID:29425170
Nakagawa, Hiroyuki; Matsuo, Yosuke; McCormick, Susan; Lim, Chee Wei
2018-05-01
A determination method previously validated for trichothecenes and zearalenone by means of liquid chromatography-tandem mass spectrometry (LC-MS/MS) was adapted for the quantification of T-2 toxin (T-2) as well as its glucoside and acetyl derivatives, T-2-3-glucoside (T-2-3G) and 3-acetyl-T-2 (3A-T-2). HT-2 toxin (HT-2) and its acetyl derivative 3-acetyl-HT-2 (3A-HT-2) were also included as the target chemicals. Staple flours (56 samples collected from the Singapore market) were examined for contamination from T-2 and/or HT-2 and their derivatives. Among them, 16 flours were found to be contaminated with T-2 and/or HT-2, whereas none was contaminated with T-2-3G and 3A-HT-2, except for trace 3A-T-2 detected in 2 rye samples. Rye flour samples were frequently contaminated with both T-2 and HT-2. Some of the reference materials (RMs) were further analyzed, and T-2-3G and 3A-T-2 were quantitatively detected in corn and wheat RMs. The ratio of T-2-3G to T-2 in the RMs seemed to be much lower than the ratio of deoxynivalenol-3-glucoside to deoxynivalenol usually reported in former studies. To the best of our knowledge, the natural contamination of 3A-T-2 in staple flour is reported here for the first time.
Cullin3 - BTB Interface: A Novel Target for Stapled Peptides
Palmieri, Maddalena; Balasco, Nicole; Esposito, Luciana; Russo, Luigi; Mazzà, Daniela; Di Marcotullio, Lucia; Di Gaetano, Sonia; Malgieri, Gaetano; Vitagliano, Luigi; Pedone, Emilia; Zaccaro, Laura
2015-01-01
Cullin3 (Cul3), a key factor of protein ubiquitination, is able to interact with dozens of different proteins containing a BTB (Bric-a-brac, Tramtrack and Broad Complex) domain. We here targeted the Cul3–BTB interface by using the intriguing approach of stabilizing the α-helical conformation of Cul3-based peptides through the “stapling” with a hydrocarbon cross-linker. In particular, by combining theoretical and experimental techniques, we designed and characterized stapled Cul3-based peptides embedding the helix 2 of the protein (residues 49–68). Intriguingly, CD and NMR experiments demonstrate that these stapled peptides were able to adopt the helical structure that the fragment assumes in the parent protein. We also show that some of these peptides were able to bind to the BTB of the tetrameric KCTD11, a substrate adaptor involved in HDAC1 degradation, with high affinity (~ 300–600 nM). Cul3-derived staple peptides are also able to bind the BTB of the pentameric KCTD5. Interestingly, the affinity of these peptides is of the same order of magnitude of that reported for the interaction of full-length Cul3 with some BTB containing proteins. Moreover, present data indicate that stapling endows these peptides with an increased serum stability. Altogether, these findings indicate that the designed stapled peptides can efficiently mimic protein-protein interactions and are potentially able to modulate fundamental biological processes involving Cul3. PMID:25848797
Strength of fixation constructs for basilar osteotomies of the first metatarsal.
Lian, G J; Markolf, K; Cracchiolo, A
1992-01-01
Twenty-four pairs of fresh-frozen human feet had a proximal osteotomy of the first metatarsal that was fixed using either screws, staples, or K wires. Each metatarsal was excised and the specimen was loaded to failure in a cantilever beam configuration by applying a superiorly directed force to the metatarsal head using an MTS servohydraulic test machine. Specimens with a crescentic osteotomy that were fixed using a single screw demonstrated higher mean failure moments than pairs that were fixed with four staples or two K wires; staples were the weakest construct. All specimens fixed with staples failed by bending of the staples without bony fracture; all K wire constructs but one failed by wire bending. Chevron and crescentic osteotomies fixed with a single screw demonstrated equal bending strengths; the bending strength of an oblique osteotomy fixed with two screws was 82% greater than for a crescentic osteotomy fixed with a single screw. Basilar osteotomies of the first metatarsal are useful in correcting metatarsus primus varus often associated with hallux valgus pathology. Fixation strength is an important consideration since weightbearing forces on the head of the first metatarsal acting at a distance from the osteotomy site subject the construct to a dorsiflexion bending moment, as simulated in our tests. Our results show that screw fixation is the strongest method for stabilizing a basilar osteotomy. Based upon the relatively low bending strengths of the staple and K wire constructs, we would not recommend these forms of fixation.(ABSTRACT TRUNCATED AT 250 WORDS)
DNA origami metallized site specifically to form electrically conductive nanowires.
Pearson, Anthony C; Liu, Jianfei; Pound, Elisabeth; Uprety, Bibek; Woolley, Adam T; Davis, Robert C; Harb, John N
2012-09-06
DNA origami is a promising tool for use as a template in the design and fabrication of nanoscale structures. The ability to engineer selected staple strands on a DNA origami structure provides a high density of addressable locations across the structure. Here we report a method using site-specific attachment of gold nanoparticles to modified staple strands and subsequent metallization to fabricate conductive wires from DNA origami templates. We have modified DNA origami structures by lengthening each staple strand in select regions with a 10-base nucleotide sequence and have attached DNA-modified gold nanoparticles to the lengthened staple strands via complementary base-pairing. The high density of extended staple strands allowed the gold nanoparticles to pack tightly in the modified regions of the DNA origami, where the measured median gap size between neighboring particles was 4.1 nm. Gold metallization processes were optimized so that the attached gold nanoparticles grew until gaps between particles were filled and uniform continuous nanowires were formed. Finally, electron beam lithography was used to pattern electrodes in order to measure the electrical conductivity of metallized DNA origami, which showed an average resistance of 2.4 kΩ per metallized structure.
Kuroda, Hiroaki; Yoshida, Tatsuya; Sakao, Yukinori
2017-12-01
We used the powered vascular staple (PVS) instead of the conventional staple technique [the utilization of the powered linier cutter (PLC)] or ligation for total 23 segmental or subsegmental bronchi with less than 10 mm in the bronchial luminal size on computed tomography (CT) in thoracoscopic segmentectomy. Our results suggested that the availability of the PVS represents a novel advance in the armamentarium and may have a possibility of being pervasive widely however, more observative periods and further sample accumulation are needed.
Langrehr, J M; Schmidt, S C; Neuhaus, P
2005-08-01
Laparoscopic inguinal hernia repair offers more rapid recovery and less pain than with the traditional open approach. However, injury to the nerves of the lumbar plexus with subsequent chronic pain or neuralgia has a reported incidence of 2% during laparoscopic hernia repair, particularly when the transabdominal preperitoneal technique (TAPP) is used. These complications are inherent to the use of staples for fixation of the mesh. To avoid nerve irritation, we considered the use of fibrin sealant for the fixation of the mesh instead of staples. The aim of this study was to evaluate this technique and to compare the short-term follow-up of these patients with patients who underwent the staple repair technique. This is the first reported use of fibrin sealant in laparoscopic TAPP hernia repair. Between September and November 2004, we performed 17 consecutive laparoscopic hernia repairs (TAPP) in 14 patients (3 bilateral hernias) with primary hernias. The prosthetic mesh was fixed (10 x 15 cm) with 1 ml fibrin. The fibrin was applied using a special laparoscopic applicator. The peritoneum was closed with absorbable sutures. The postoperative course of these patients was compared with a cohort of matched patients who received the traditional staple fixation of the prosthetic mesh. Patients were evaluated at a median follow-up of 10.4 months (3.8-16.0 months). All patients underwent postoperative physical examinations. No recurrent hernia was found. There were 2 seromas and one hematoma in the stapled group. In the stapled group, one patient had pain in the area of the lateral femoral cutaneous nerve. There was no postoperative complication in the non-stapled group. Fibrin fixation of the mesh during laparoscopic transabdominal preperitoneal inguinal hernia repair is feasible without higher risk of recurrences. In addition the fibrin fixation method may decrease postoperative neuralgia and reduce the incidence of postoperative seromas and hematomas.
Braun, John T; Akyuz, Ephraim; Ogilvie, James W; Bachus, Kent N
2005-09-01
Scoliosis is a complex three-dimensional deformity with limited treatment options. Current treatments present potential problems that may be addressed with use of fusionless techniques for the correction of scoliosis. However, there are few data comparing the efficacy of different fusionless implant strategies in controlling scoliosis or on the integrity of rigid compared with flexible devices in an in vivo setting over time. The objective of this study was to compare the efficacy and integrity of rigid and flexible anterior thoracic tethers used to treat experimental scoliosis. Experimental scoliosis was created in twenty-four Spanish Cross-X female goats and was subsequently treated with either anterior shape memory alloy staples or anterior ligament tethers attached to bone anchors. Serial radiographs were analyzed to determine the efficacy of the implants in controlling scoliosis progression as well as the integrity of the implants at study completion. After the goats were killed, the implants were analyzed with use of three quantitative indices of implant integrity and implant pullout testing. Over the treatment period, scoliosis progressed from 77.3 degrees to 94.3 degrees in the goats treated with staples and was corrected from 73.4 degrees to 69.9 degrees in the goats treated with bone anchors, with loosening of eighteen of forty-two staples (two of the eighteen dislodged) and evidence of drift in two of forty-nine anchors. Histologic sections revealed a consistent halo of fibrous tissue around the staple tines but well-fixed bone anchors at all sites. Pullout testing demonstrated that bone anchors had greater strength than staples initially and at the study completion, with an increase in bone anchor fixation over the course of the study. In this scoliosis model, the flexible ligament tethers attached to bone anchors demonstrated greater efficacy and integrity than the more rigid shape memory alloy staples.
Ultrastructural analysis of different-made staplers' staples.
Gentilli, S; Portigliotti, L; Aronici, M; Ferrante, D; Surico, D; Milanesio, M; Gianotti, V; Gatti, G; Addante, A; Garavoglia, M
2012-10-01
Recently, Chinese-made mechanical staplers with lower price respect to American-made ones have been introduced in clinical practice. In literature, small case series compare the clinical outcomes of different staplers concluding that the new stapler devices perform as well as the American ones. The aim of this study is to compare with an ultrastructural analysis the staples of different staplers in order to verify the existence of differences that might explain significant price disparity and condition clinical outcomes. Each stapler was subjected to morphological analysis, energy dispersive X-Ray spectroscopy, metal release assessment followed by inductively coupled plasma mass spectroscopy. P-values were considered statistically significant when <0.05. Autosuture staples have square section whereas the other American one and Chinese made staples have round sections. Roughness index and chips presence before and after ageing tests were comparable for all samples except for Ethicon Endo-Surgery stapler. Energy dispersive X-Ray spectroscopy showed that all staplers are made of pure Titanium but Ethicon Endo-Surgery staples are made with an alloy. Metal release analysis release statistically significant differences between samples in simulated body fluid 20 days solution (P=0.002) and in Aquaregia at 14 days solution. Discussion. Stapling devices have became routinely used in gastrointestinal surgery mainly because of operative time reduction. Recently, new Chinese-made mechanical staplers, with significantly lower prices, have been introduced in clinical practice. In literature, there are some studies that compare clinical outcomes of American-made and Chinese-made staplers on small groups of patients but doesn't exist any work which consider structural differences between traditional and new devices. In our study, for the first time, we propose a comparison between two American-made staplers and three Chinese-made staplers which evaluate morphology, metal composition and chemical staples release. Our study suggest that there are some ultrastructural differences between commercially available staplers with no correlation to price disparity. More studies are needed to confirm our results and to verify if our findings could condition clinical outcomes.
Mattei, Josiemer; Malik, Vasanti; Wedick, Nicole M; Hu, Frank B; Spiegelman, Donna; Willett, Walter C; Campos, Hannia
2015-06-04
The prevalence of type 2 diabetes has been reaching epidemic proportions across the globe, affecting low/middle-income and developed countries. Two main contributors to this burden are the reduction in mortality from infectious conditions and concomitant negative changes in lifestyles, including diet. We aimed to depict the current state of type 2 diabetes worldwide in light of the undergoing epidemiologic and nutrition transition, and to posit that a key factor in the nutrition transition has been the shift in the type and processing of staple foods, from less processed traditional foods to highly refined and processed carbohydrate sources. We showed data from 11 countries participating in the Global Nutrition and Epidemiologic Transition Initiative, a collaborative effort across countries at various stages of the nutrition-epidemiologic transition whose mission is to reduce diabetes by improving the quality of staple foods through culturally-appropriate interventions. We depicted the epidemiologic transition using demographic and mortality data from the World Health Organization, and the nutrition transition using data from the Food and Agriculture Organization food balance sheets. Main staple foods (maize, rice, wheat, pulses, and roots) differed by country, with most countries undergoing a shift in principal contributors to energy consumption from grains in the past 50 years. Notably, rice and wheat products accounted for over half of the contribution to energy consumption from staple grains, while the trends for contribution from roots and pulses generally decreased in most countries. Global Nutrition and Epidemiologic Transition Initiative countries with pilot data have documented key barriers and motivators to increase intake of high-quality staple foods. Global research efforts to identify and promote intake of culturally-acceptable high-quality staple foods could be crucial in preventing diabetes. These efforts may be valuable in shaping future research, community interventions, and public health and nutritional policies.
Small intestinal volvulus caused by loose surgical staples.
Page, Matthew P; Kim, Heung Bae; Fishman, Steven J
2009-09-01
Small intestinal volvulus beyond infancy is rare and usually has an iatrogenic cause. The authors describe an adolescent boy with small bowel volvulus secondary to the presence of free intraperitoneal surgical staples after a laparoscopic appendectomy.
78 FR 26791 - Government-Owned Inventions; Availability for Licensing
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-08
... 301-435-0103. Stapled Peptides for Treatment of Cardiovascular Diseases and Inflammation Description... inflammation and cardiovascular diseases, including hyperlipidemia, atherosclerosis, restenosis, and acute...-stapled Apolipoprotein Peptide Mimetics for the Treatment of Cardiovascular Diseases and Inflammation. For...
[Technical considerations on 222 cases of esophageal anastomosis using a stapler].
Liboni, A; Zamboni, P; Mari, C; Uzzau, A; Salomoni, C; Brunelli, G; Buccoliero, F; Donini, I
1989-05-01
The Authors report their experience with 222 esophagoenteric anastomoses, performed in 211 cases for malignant neoplasms (middle and lower third) of the esophagus or stomach. Particularly, they have performed 4 Sujura operations, 31 esophagogastric, 4 esophagocolic, 183 esophagojejunal anastomoses utilizing SPTU, ILS and EEA circular stapler. GIA was used in the preparation of the stomach before esophagogastroplasty. Mortality rate of the manual period (1970-1980: 114 cases operated) was 14.5% versus 2.2% of the stapling period (1981-1987: 222 cases operated). From the technical point of view reasons of the superiority of stapled technique are discussed and summarized as follows: 1) space not favourable for handsewn anastomoses; 2) stapled technique allows the surgeon to save anastomoses vascularization; 3) the stapler performs the suture simultaneously so to reduce tensile strength on the anastomoses and the fragile esophageal wall especially; 4) stapled agraphes are fixed in three points vs. the two points of the handsewn stitches.
Complications and results after stapled haemorrhoidopexy as a day surgical procedure.
Mlakar, B; Kosorok, P
2003-10-01
The aim of this report is to describe our experience with stapled haemorrhoidopexy as a day surgery procedure. From January 2000 to January 2003, a total of 214 patients with third- and fourth-degree haemorrhoids underwent stapled haemorrhoidopexy under spinal anaesthesia. We analysed early postoperative complications and long-term results. Patients were followed for 4-36 months (mean, 22 months). Only 3 patients (1%) were hospitalised. The long-term complications were analysed by means of a mailed questionnaire. Minor bleeding at wiping after defecation was observed by 9% of patients and minor haemorrhoidal prolapse by 8% of patients. Pain after defecation was reported by 6% of patients and anal stenosis occurred in 2% of them. Faecal urgency was reported by 3% of patients with previously unknown incontinence problems. According to our experience, stapled haemorrhoidopexy can be safely performed as a day surgery procedure.
Sivers and Boer-Mulders observables from lattice QCD
NASA Astrophysics Data System (ADS)
Musch, B. U.; Hägler, Ph.; Engelhardt, M.; Negele, J. W.; Schäfer, A.
2012-05-01
We present a first calculation of transverse momentum-dependent nucleon observables in dynamical lattice QCD employing nonlocal operators with staple-shaped, “process-dependent” Wilson lines. The use of staple-shaped Wilson lines allows us to link lattice simulations to TMD effects determined from experiment, and, in particular, to access nonuniversal, naively time-reversal odd TMD observables. We present and discuss results for the generalized Sivers and Boer-Mulders transverse momentum shifts for the SIDIS and DY cases. The effect of staple-shaped Wilson lines on T-even observables is studied for the generalized tensor charge and a generalized transverse shift related to the worm-gear function g1T. We emphasize the dependence of these observables on the staple extent and the Collins-Soper evolution parameter. Our numerical calculations use an nf=2+1 mixed action scheme with domain wall valence fermions on an Asqtad sea and pion masses 369 MeV as well as 518 MeV.
Outcomes of mechanical stapling for postlaryngectomy open pharyngotomy closure.
Paddle, Paul; Husain, Inna; McHugh, Lauren; Franco, Ramon
2017-03-01
A total laryngectomy (TL) is performed as a primary or salvage therapy for laryngeal carcinoma. Pharyngotomy closure after TL is typically performed using manual sutures. Automatic stapling devices are routinely used in thoracoabdominal surgery, but have not been widely accepted for use in pharyngotomy closure. Previously described closed stapling techniques of pharyngeal closure do not allow direct evaluation of surgical margins and are limited to endolaryngeal disease. We describe an open technique for pharyngotomy closure using a mechanical stapling device. Retrospective review. A review was conducted of 16 total laryngectomies performed from May 2008 to August 2015 utilizing an Ethicon Endopath ETS Compact-Flex 45 stapler. Sixteen patients (15 male, one female), mean age 69 years, received open TL (14 salvage, two primary) with endostapler pharyngeal closure and primary tracheoesophageal puncture (TEP). Surgical time averaged 218 minutes. Median time to swallowing was 4 days (range, 2-240 days) and mean hospital stay 6 days (range, 3-10 days). Fistula incidence was 31% (5/16) overall and 36% (5/14) in the postradiation patients. Mechanical stapling is a simple method for postlaryngectomy open pharyngotomy closure. This technique allows evaluation of margins, easy primary TEP, and the opportunity for early swallowing and shorter hospital stays. In addition, it can be performed for closure of salvage laryngectomies with rates of fistula formation similar to that found in the literature using suture closure techniques. Future studies are necessary to compare oncological results and surgical complications between the open and closed stapling techniques and to traditional suture closure. 4 Laryngoscope, 127:605-610, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.
Hydrocarbon-stapled lipopeptides exhibit selective antimicrobial activity.
Jenner, Zachary B; Crittenden, Christopher M; Gonzalez, Martín; Brodbelt, Jennifer S; Bruns, Kerry A
2017-05-01
Antimicrobial peptides (AMPs) occur widely in nature and have been studied for their therapeutic potential. AMPs are of interest due to the large number of possible chemical structural combinations using natural and unnatural amino acids, with varying effects on their biological activities. Using physicochemical properties from known naturally occurring amphipathic cationic AMPs, several hydrocarbon-stapled lipopeptides (HSLPs) were designed, synthesized, and tested for antimicrobial properties. Peptides were chemically modified by N-terminal acylation, C-terminal amidation, and some were hydrocarbon stapled by intramolecular olefin metathesis. The effects of peptide length, amphipathic character, and stapling on antimicrobial activity were tested against Escherichia coli, three species of Gram-positive bacteria (Staphylococcus aureus, Bacillus megaterium, and Enterococcus faecalis), and two strains of Candida albicans. Peptides were shown to disrupt liposomes of different phospholipid composition, as measured by leakage of a fluorescent compound from vesicles. Peptides with (S)-2-(4'-pentenyl)-alanine substituted for l-alanine in a reference peptide showed a marked increase in antimicrobial activity, hemolysis, and membrane disruption. Stapled peptides exhibited slightly higher antimicrobial potency; those with greatest hydrophobic character showed the greatest hemolysis and liposome leakage, but lower antimicrobial activity. The results support a model of HSLPs as membrane-disruptive AMPs with potent antimicrobial activity and relatively low hemolytic potential at biologically active peptide concentrations. © 2017 Wiley Periodicals, Inc.
Vinod, Shalini K; Lim, Karen; Bell, Lauren; Veera, Jacqueline; Ohanessian, Lucy; Juresic, Ewa; Borok, Nira; Chan, Phillip; Chee, Raphael; Do, Viet; Govindarajulu, Geetha; Sridharan, Swetha; Johnson, Carol; Moses, Daniel; Van Dyk, Sylvia; Holloway, Lois
2017-02-01
Image-based brachytherapy for cervical cancer using MRI has been implemented in Australia and New Zealand. The aims of this study were to measure variability in High-risk CTV (HR-CTV) delineation and evaluate dosimetric consequences of this. Nine radiation oncologists, one radiation therapist and two radiologists contoured HR-CTV on 3T MRI datasets from ten consecutive patients undergoing cervical brachytherapy at a single institution. Contour comparisons were performed using the Dice Similarity Coefficient (DSC) and Mean Absolute Surface Distance (MASD). Two reference contours were created for brachytherapy planning: a Simultaneous Truth and Performance Level Estimation (STAPLE) and a consensus contour (CONSENSUS). Optimized plans (8 Gy) for both these contours were applied to individual participant's contours to assess D90 and D100 coverage of HR CTV. To compare variability in dosimetry, relative standard deviation (rSD) was calculated. Good concordance (mean DSC≥0.7, MASD≤5 mm) was achieved in 8/10 cases when compared to the STAPLE reference and 6/10 cases when compared to the CONSENSUS reference. Greatest variation was visually seen in the cranio-caudal direction. The average mean rSD across all patients was 27% and 34% for the STAPLE HR-CTV D90 and D100, respectively, and 28% and 35% for the CONSENSUS HR-CTV D90 and D100. Delineation uncertainty resulted in an average dosimetric uncertainty of ±1.5-1.6 Gy per fraction based on an 8 Gy prescribed fraction. Delineation of HR-CTV for cervical cancer brachytherapy was consistent amongst observers, suggesting similar interpretation of GEC-ESTRO guidelines. Despite the good concordance, there was dosimetric variation noted, which could be clinically significant. © 2016 The Royal Australian and New Zealand College of Radiologists.
Wong, J C H; Chung, C C; Yau, K K; Cheung, H Y S; Wong, D C T; Chan, O C Y; Li, M K W
2008-04-01
This study was designed to compare stapled vs. conventional hemorrhoidectomy for patients with acute thrombosed hemorrhoids. Forty-one patients with acute thrombosed hemorrhoids were randomized into: 1) stapled hemorrhoidectomy (PPH group; n = 21), and 2) open hemorrhoidectomy (open group; n = 20). Emergency surgery was performed with perioperative data and complications were recorded. Patients were followed up by independent assessors to evaluate pain, recurrence, continence function, and satisfaction at regular intervals. The median follow-up for the PPH group and open group were 59 and 56 weeks, respectively. There was no significant difference in terms of the hospital stay, complication rate, and continence function; however, the mean pain intensity in the first postoperative week was significantly less in the PPH group (4.1 vs. 5.7, P = 0.02). Patients in the PPH group recovered significantly faster in terms of the time to become analgesic-free (4 vs. 8.5 days, P < 0.01), time to become pain-free (9 vs. 20.5 days, P = 0.01), resumption of work (7 vs. 12.5 days, P = 0.01), and time for complete wound healing (2 vs. 4 weeks, P < 0.01). On long-term follow-up, significantly fewer patients in the PPH group complained of recurrent symptoms (0 vs. 5, P = 0.02). The overall symptom improvement and patients' satisfaction were significantly better in the PPH group (90 vs. 80 percent, P = 0.03 and +3 vs. +2, P < 0.01 respectively). Stapled hemorrhoidectomy is safe and effective for acute thrombosed hemorrhoids. Similar to elective stapled procedure, emergency stapled excision has greater short-term benefits compared with conventional excision: diminished pain, faster recovery, and earlier return to work. Long-term results and satisfaction were excellent.
Murata, Yasuhiro; Tanemura, Akihiro; Kato, Hiroyuki; Kuriyama, Naohisa; Azumi, Yoshinori; Kishiwada, Masashi; Mizuno, Shugo; Usui, Masanobu; Sakurai, Hiroyuki; Isaji, Shuji
2017-08-01
Delayed gastric emptying (DGE) is the most common complication following pancreaticoduodenectomy (PD). The clinical efficacy of stapled side-to-side anastomosis using a laparoscopic stapling device during alimentary reconstruction in PD is not well understood and its superiority over conventional hand-sewn end-to-side anastomosis remains controversial. The objective of this study was to evaluate the effectiveness of the stapled side-to-side anastomosis in preventing the development of DGE after PD. The subjects of this retrospective study were 137 patients who underwent pancreaticoduodenectomy, as subtotal stomach-preserving pancreaticoduodenectomy (SSPPD; n = 130), or conventional whipple procedure (n = 7) with Child reconstruction, between January 2010 and May 2014. The patients were divided into two groups according to whether they had had a stapled side-to-side anastomosis (SA group; n = 57) or a conventional hand-sewn end-to-side anastomosis (HA group; n = 80). SA reduced the operative time (SA vs. HA: 508 vs. 557 min, p = 0.028) and the incidence of delayed gastric emptying (SA vs. HA: 21.1 vs. 46.3%, p = 0.003) and was associated with shorter hospitalization (SA vs. HA: 33 vs. 39.5 days, p = 0.007). In this cohort, SA was the only significant factor contributing to a reduction in the incidence of DGE (p = 0.002). Stapled side-to-side gastrojejunostomy reduced the operative time and the incidence of DGE following PD with Child reconstruction, thereby also reducing the length of hospitalization.
Routine intraoperative leak testing for sleeve gastrectomy: is the leak test full of hot air?
Bingham, Jason; Lallemand, Michael; Barron, Morgan; Kuckelman, John; Carter, Preston; Blair, Kelly; Martin, Matthew
2016-05-01
Staple line leak after sleeve gastrectomy (SG) is a rare but dreaded complication with a reported incidence of 0% to 8%. Many surgeons routinely test the staple line with an intraoperative leak test (IOLT), but there is little evidence to validate this practice. In fact, there is a theoretical concern that the leak test may weaken the staple line and increase the risk of a postop leak. Retrospective review of all SGs performed over a 7-year period was conducted. Cases were grouped by whether an IOLT was performed, and compared for the incidence of postop staple line leaks. The ability of the IOLT for identifying a staple line defect and for predicting a postoperative leak was analyzed. Five hundred forty-two SGs were performed between 2007 and 2014. Thirteen patients (2.4%) developed a postop staple line leak. The majority of patients (n = 494, 91%) received an IOLT, including all 13 patients (100%) who developed a subsequent clinical leak. There were no (0%) positive IOLTs and no additional interventions were performed based on the IOLT. The IOLT sensitivity and positive predictive value were both 0%. There was a trend, although not significant, to increase leak rates when a routine IOLT was performed vs no routine IOLT (2.6% vs 0%, P = .6). The performance of routine IOLT after SG provided no actionable information, and was negative in all patients who developed a postoperative leak. The routine use of an IOLT did not reduce the incidence of postop leak, and in fact was associated with a higher leak rate after SG. Published by Elsevier Inc.
Aiyer, Amiethab; Russell, Nicholas A; Pelletier, Matthew H; Myerson, Mark; Walsh, William R
2016-06-01
Background The optimal fixation method for the first tarsometatarsal arthrodesis remains controversial. This study aimed to develop a reproducible first tarsometatarsal testing model to evaluate the biomechanical performance of different reconstruction techniques. Methods Crossed screws or a claw plate were compared with a single or double shape memory alloy staple configuration in 20 Sawbones models. Constructs were mechanically tested in 4-point bending to 1, 2, and 3 mm of plantar displacement. The joint contact force and area were measured at time zero, and following 1 and 2 mm of bending. Peak load, stiffness, and plantar gapping were determined. Results Both staple configurations induced a significantly greater contact force and area across the arthrodesis than the crossed screw and claw plate constructs at all measurements. The staple constructs completely recovered their plantar gapping following each test. The claw plate generated the least contact force and area at the joint interface and had significantly greater plantar gapping than all other constructs. The crossed screw constructs were significantly stiffer and had significantly less plantar gapping than the other constructs, but this gapping was not recoverable. Conclusions Crossed screw fixation provides a rigid arthrodesis with limited compression and contact footprint across the joint. Shape memory alloy staples afford dynamic fixation with sustained compression across the arthrodesis. A rigid polyurethane foam model provides an anatomically relevant comparison for evaluating the interface between different fixation techniques. Clinical Relevance The dynamic nature of shape memory alloy staples offers the potential to permit early weight bearing and could be a useful adjunctive device to impart compression across an arthrodesis of the first tarsometatarsal joint. Therapeutic, Level V: Bench testing. © 2015 The Author(s).
Staple Line Reinforcement with Stitch in Laparoscopic Sleeve Gastrectomies. Is It Useful or Harmful?
Albanopoulos, Konstantinos; Tsamis, Dimitrios; Arapaki, Aggeliki; Kleidi, Eleftheria; Zografos, Georgios; Leandros, Emmanouil
2015-07-01
Reinforcement of the staple line in laparoscopic sleeve gastrectomy (LSG) is a practice that leads to less morbidity, but equivocal results have been reported in the literature. This is a prospective randomized study comparing two groups of patients who underwent LSG. In one group LSG was performed with a running absorbable suture placement at the staple line. In the other group the running suture was not placed. General data of the patients, as well as intraoperative and postoperative data, were gathered and statistically analyzed. Overall, 146 patients were subjected to LSG. In 84 patients a running suture was placed, and in 62 patients no suture was placed. No significant differences were found between the two groups in demographic data. No significant differences were found also in the intraoperative data, such as number of trocars, number and type of cartridges, drain placement, and operative time (45±21 versus 40±20 minutes, respectively; P<.05). Intraoperative complications were significantly more in the group with the suture placement (33.3% versus 16.1%, respectively; P<.05). Hematomas developed intraoperatively in more patients after the placement of the running suture (9.5% versus 0.0%, respectively; P<.05). Postoperatively, there was no significant difference in morbidity between the two groups (8.3% versus 9.7%, respectively; P>.05). After this randomized study, final conclusions about the efficacy of this running suture to the staple line cannot be made. To the contrary, problems seem to exist after such reinforcement of the staple line, such as hematomas. Dealing with possible leaks and hemorrhage of the staple line is also problematic after placement of the running suture.
Staples.com: Focus on Usability.
ERIC Educational Resources Information Center
McCann, Tom; Hynes, Colin
2002-01-01
Describes the Staples.com electronic commerce Web site; discusses its steady growth rate; and details two case studies in which data from a variety of sources were used to identify and resolve site usability issues and which are supported by compelling ROI (return on investment) figures. (Author/LRW)
Mounsey, Anne L; Halladay, Jacqueline; Sadiq, Timothy S
2011-07-15
Most patients with hemorrhoids experience only mild symptoms that can be treated with nonprescription topical preparations. Patients usually seek treatment when symptoms increase. Internal hemorrhoids typically present with prolapse or painless rectal bleeding. External hemorrhoids also bleed and can cause acute pain if thrombosed. Medical therapy should be initiated with stool softeners plus local therapy to relieve swelling and symptoms. If medical therapy is inadequate, surgical intervention is warranted. Rubber band ligation is the treatment of choice for grades 1 and 2 hemorrhoids. Rubber band ligation, excisional hemorrhoidectomy, or stapled hemorrhoidopexy can be performed in patients with grade 3 hemorrhoids. Rubber band ligation causes less postoperative pain and fewer complications than excisional hemorrhoidectomy and stapled hemorrhoidopexy, but has a higher recurrence rate. Excisional hemorrhoidectomy or stapled hemorrhoidopexy is recommended for treatment of grade 4 hemorrhoids. Stapled hemorrhoidopexy has a faster postoperative recovery, but a higher recurrence rate. Postoperative pain from excisional hemorrhoidectomy can be treated with nonsteroidal anti-inflammatory drugs, narcotics, fiber supplements, and topical antispasmodics. Thrombosed external hemorrhoids can be treated conservatively or excised.
The stapled hemorrhoidopexy syndrome: a new clinical entity?
Efthimiadis, Chr; Kosmidis, Chr; Grigoriou, M; Anthimidis, G; Vasiliadou, K; Baka, S; Gerasimidou, D; Basdanis, G
2011-10-01
Haemorrhoidal disease is a rather common disease of unknown cause. A new technique for treating prolapsing haemorrhoids known as the stapled hemorrhoidopexy (SH) or the "Longo procedure" is widely used. Serious adverse events were reported in 2000 and some discussion over the syndrome but nothing since. Two hundred and five patients underwent SH by our surgical team at the Interbalkan European Medical Center. Modified SH was performed. Despite the low incidence of postoperative complications (11/205), 36.58% of patients developed syndrome comprised of urgency to defecate, sensation of anal foreign body and incomplete defecation and mild cramp like anal discomfort, immediately after surgery or in the following 48 h. There is not statistically significant relationship between the presence of the syndrome and the gender, the presence of muscle fibres in the resected "ring" the degree of haemorrhoidal disease, age and ring length. Observations led us to conclude that the stapled hemorrhoidopexy syndrome (SHS) is probably caused by the irritating presence of the titanium staples in the rectal mucosa and by the resection itself.
Long-term prospective evaluation of intestinal anastomosis using stainless steel staples in 14 dogs
Benlloch-Gonzalez, Manuel; Gomes, Eymeric; Bouvy, Bernard; Poncet, Cyrill
2015-01-01
This prospective clinical study evaluated the use, complications, and clinical and ultrasonographic follow-ups of end-to-end intestinal anastomoses with skin staples in naturally occurring diseases in canine small and large intestines. Intestinal anastomoses were performed in 14 dogs and pre-, peri-, and postoperative data were recorded. Postoperative clinical and ultrasound evaluations were performed at regular intervals for 1 year. The mean time taken to construct the anastomosis was 5 min. There were no intraoperative complications. Hemorrhage and colonic stricture were the main postoperative complications. Staple loss occurred in 2 cases. Absence of wall layering and focal wall thickening were observed in all cases at each ultrasonographic follow-up. Hyperechoic fat was observed in all but 1 of the cases at month 1. Nine dogs were alive with normal digestive function at the end of the study. The skin stapler technique enabled rapid construction of consistent anastomoses with inexpensive stapling material. PMID:26130833
Fujimoto, S; Takahashi, M; Endoh, F; Takai, M; Kobayashi, K; Kiuchi, S; Konno, C; Obata, G; Okui, K
1991-09-01
From January 1983 to December 1989, we performed esophagojejunostomy on 379 patients who underwent total gastrectomy for gastric cancer. A mechanical EEA stapler or conventional manual suturing was used. The clinical outcomes of 199 patients in whom stapling was used (stapler group) and 180 patients in whom manual suturing was done (manual group) were compared. Two of the 199 patients in the stapler group and 3 of the 180 patients in the manual group died of causes directly related to the anastomosis. In the stapler group, 16 stapled anastomoses were formed supradiaphragmatically, and manual suturing was done for 6 patients. The highly placed anastomosis was formed without left thoracotomy or with median sternotomy in 8 of the 16 patients in whom the stapling device was used and in 1 of the 6 patients in whom manual suturing was used. The incidence of anastomotic leakage and stenosis did not differ between the groups. Thus, the mechanical stapler facilitated the construction of a rapid, reliable esophagojejunostomic anastomosis.
The double stapling technique for low anterior resection. Results, modifications, and observations.
Griffen, F D; Knight, C D; Whitaker, J M; Knight, C D
1990-01-01
Since the introduction of the end-to-end anastomosis (EEA) stapler for rectal reconstruction, we have used a modification of the conventional technique in which the lower rectal segment is closed with the linear stapler (TA-55) and the anastomosis is performed using the EEA instrument across the linear staple line (double stapling technique). Our experience with this procedure includes stapled colorectal anastomoses in 75 patients and is the basis for the report. This review presents the details and advantages of the technique and the results. Complications include two patients with anastomotic leak (2.7%), and two with stenosis that required treatment (2.7%). Protective colostomy was not done in this series. There were no deaths. Our experience and that of others suggests that this modification of the EEA technique can allow a lower anastomosis in some patients, and that it can be done with greater safety and facility. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:2357137
Sivers and Boer-Mulders observables from lattice QCD.
DOE Office of Scientific and Technical Information (OSTI.GOV)
B.U. Musch, Ph. Hagler, M. Engelhardt, J.W. Negele, A. Schafer
We present a first calculation of transverse momentum dependent nucleon observables in dynamical lattice QCD employing non-local operators with staple-shaped, 'process-dependent' Wilson lines. The use of staple-shaped Wilson lines allows us to link lattice simulations to TMD effects determined from experiment, and in particular to access non-universal, naively time-reversal odd TMD observables. We present and discuss results for the generalized Sivers and Boer-Mulders transverse momentum shifts for the SIDIS and DY cases. The effect of staple-shaped Wilson lines on T-even observables is studied for the generalized tensor charge and a generalized transverse shift related to the worm gear function g{submore » 1}T. We emphasize the dependence of these observables on the staple extent and the Collins-Soper evolution parameter. Our numerical calculations use an n{sub f} = 2+1 mixed action scheme with domain wall valence fermions on an Asqtad sea and pion masses 369 MeV as well as 518 MeV.« less
Watson, Angus J M; Bruhn, Hanne; MacLeod, Kathleen; McDonald, Alison; McPherson, Gladys; Kilonzo, Mary; Norrie, John; Loudon, Malcolm A; McCormack, Kirsty; Buckley, Brian; Brown, Steven; Curran, Finlay; Jayne, David; Rajagopal, Ramesh; Cook, Jonathan A
2014-11-11
Current interventions for haemorrhoidal disease include traditional haemorrhoidectomy (TH) and stapled haemorrhoidopexy (SH) surgery. However, uncertainty remains as to how they compare from a clinical, quality of life (QoL) and economic perspective. The study is therefore designed to determine whether SH is more effective and more cost-effective, compared with TH. eTHoS (either Traditional Haemorrhoidectomy or Stapled Haemorrhoidopexy for Haemorrhoidal Disease) is a pragmatic, multicentre, randomised controlled trial. Currently, 29 secondary care centres are open to recruitment. Patients, aged 18 year or older, with circumferential haemorrhoids grade II to IV, are eligible to take part. The primary clinical and economic outcomes are QoL profile (area under the curve derived from the EuroQol Group's 5 Dimension Health Status Questionnaire (EQ-5D) at all assessment points) and incremental cost per quality adjusted life year (QALY) based on the responses to the EQ-5D at 24 months. The secondary outcomes include a comparison of the SF-36 scores, pain and symptoms sub-domains, disease recurrence, complication rates and direct and indirect costs to the National Health Service (NHS). A sample size of n =338 per group has been calculated to provide 90% power to detect a difference in the mean area under the curve (AUC) of 0.25 standard deviations derived from EQ-5D score measurements, with a two-sided significance level of 5%. Allowing for non-response, 400 participants will be randomised per group. Randomisation will utilise a minimisation algorithm that incorporates centre, grade of haemorrhoidal disease, baseline EQ-5D score and gender. Blinding of participants and outcome assessors is not attempted. This is one of the largest trials of its kind. In the United Kingdom alone, 29,000 operations for haemorrhoidal disease are done annually. The trial is therefore designed to give robust evidence on which clinicians and health service managers can base management decisions and, more importantly, patients can make informed choices. Current Controlled Trials ISRCTN80061723 (assigned 8 March 2010).
Synthesis of all-hydrocarbon stapled α-helical peptides by ring-closing olefin metathesis.
Kim, Young-Woo; Grossmann, Tom N; Verdine, Gregory L
2011-06-01
This protocol provides a detailed procedure for the preparation of stapled α-helical peptides, which have proven their potential as useful molecular probes and as next-generation therapeutics. Two crucial features of this protocol are (i) the construction of peptide substrates containing hindered α-methyl, α-alkenyl amino acids and (ii) the ring-closing olefin metathesis (RCM) of the resulting resin-bound peptide substrates. The stapling systems described in this protocol, namely bridging one or two turns of an α-helix, are highly adaptable to most peptide sequences, resulting in favorable RCM kinetics, helix stabilization and promotion of cellular uptake.
Design of stapled DNA-minor-groove-binding molecules with a mutable atom simulated annealing method
NASA Astrophysics Data System (ADS)
Walker, Wynn L.; Kopka, Mary L.; Dickerson, Richard E.; Goodsell, David S.
1997-11-01
We report the design of optimal linker geometries for the synthesis of stapledDNA-minor-groove-binding molecules. Netropsin, distamycin, and lexitropsinsbind side-by-side to mixed-sequence DNA and offer an opportunity for thedesign of sequence-reading molecules. Stapled molecules, with two moleculescovalently linked side-by-side, provide entropic gains and restrain theposition of one molecule relative to its neighbor. Using a free-atom simulatedannealing technique combined with a discrete mutable atom definition, optimallengths and atomic composition for covalent linkages are determined, and anovel hydrogen bond `zipper' is proposed to phase two molecules accuratelyside-by-side.
Uçvet, Ahmet; Gursoy, Soner; Sirzai, Serdar; Erbaycu, Ahmet E; Ozturk, Ali A; Ceylan, Kenan C; Kaya, Seyda O
2011-04-01
There is debate about which bronchial closure technique is the best to prevent bronchopleural fistulas (BPFs). We aim to assess the effect of bronchial closure procedures and patients' characteristics on BPF occurrence in pulmonary resections. Bronchial closures in 625 consecutive patients were assessed. Stumps were closed by manual suturing in 204 and by mechanical stapling in 421 cases. In the mechanical stapling group, stapling supported by manual suture was performed in 170 cases. BPFs occurred in 3.8%. Of these, stapling was used in 5.0%, whereas manual suturing was used in 1.5% (P=0.04). BPFs were more prevalent among patients who had undergone pneumonectomy (P<0.01), right pneumonectomy (P<0.01), stapler closure (P<0.01), patients with co-factors (P<0.01), and patients who had undergone preoperative neo-adjuvant (P=0.01) or postoperative adjuvant therapy (P=0.03). There was no difference in the frequency of BPF between patients with and without adjuvant support in the stapling group. The optimum bronchial closure method has to be chosen by considering the patient and bronchus based characteristics. This has to be assessed carefully, especially in pneumonectomy and co-factors. The manual closure seems to be the more preferable method in risky patients. An additive support suture on the bronchial stump does not decrease the risk of BPF.
Tomographie par coherence optique pour le guidage de chirurgies minimalement invasives du rachis
NASA Astrophysics Data System (ADS)
Beaudette, Kathy
Adolescent idiopathic scoliosis is a complex 3D deformity of the spine which requires surgical intervention in severe cases of the condition. The existing corrective procedure of scoliosis is very invasive; it involves a long incision and a large instrumentation, in addition to the fusion of a section of the spine. To improve postoperative conditions and to preserve patients' spinal flexibility, novel fusionless surgical approaches involving growth modulation are under investigation. With this objective in mind, a multidisciplinary team from École Polytechnique of Montreal and Sainte-Justine University Hospital Research Center is developing a surgical technique based on the insertion of micro-staples between vertebral growth plates and corresponding intervertebral disks. Each micro-staple passively modulates the vertebral growth on the convex side of the scoliotic curvature. This modulation modifies vertebral geometry which, for scoliotic patients, presents a wedging deformity. The modulation induced by these devices could lead to the correction of the curvature of the spine. This innovative procedure would preserve the flexibility of the spine as well as the health of intervertebral disks, in addition to being compatible with minimally invasive approaches. However, to be efficient, the micro-staples must be placed at the junction between the growth plate and the disk with a sub-millimeter precision. An intraoperative guiding system is therefore required to ensure the success of the intervention. Optical coherence tomography (OCT) is a promising candidate for this application. OCT is based on low-coherence interferometry and provides cross-sectional images with a resolution about 10 μm for a depth of 2 to 3 mm. This technique allows for the real-time acquisition of images and is compatible with endoscopy, thereby showing a potential for the intraoperative guidance of minimally invasive surgeries (MIS) of the spine. The main objective of this master's project is therefore to evaluate the possibility of using OCT to localize as well as identify spinal structures (such as growth plates, osseous tissue, intervertebral disks and connective tissue) and to guide the insertion of micro-staples. To attain this objective, an OCT handheld probe was designed and developed according to the surgical constraints of MIS performed by thoracoscopy (through the thorax). This probe has an external diameter of 17 mm and is 30 cm long. Coupled with a fibered interferometer, the axial and lateral resolutions of the probe are of 16 and 27 μm respectively. The OCT probe was used in vivo during an open surgery on a porcine model. Different tissues within the operative window (lung, muscles, osseous tissues and intervertebral disk) were imaged during the procedure. These preliminary in vivo tests demonstrated that the probe is capable of identifying different types of tissue with a good sensitivity and an adequate penetration depth. These results also showed that a visual inspection of the in vivo OCT images alone is not sufficient to localize the growth plates on the vertebrae. An ex vivo study using porcine vertebrae was therefore performed to identify quantitative markers in order to facilitate the interpretation of in vivo OCT images. OCT images were initially compared to corresponding histological sections. The ensuing results showed that the connective tissue layer presents a band pattern due to the birefringence properties of the collagen-rich tissue. The intervertebral disk was also shown to have a characteristic lamellar structure on OCT images. Lastly, within growth plate and osseous tissue locations, the OCT signal decay is monotonic, but with different attenuation coefficients (different slopes). Relative attenuation coefficients were therefore measured for each tissue (growth plate, osseous tissue, connective tissue and intervertebral disk) on several specimens and were compared. These results showed that growth plates present an average relative attenuation coefficient statistically different from the other tissues. An automatic growth plate segmentation algorithm was then developed and tested. The algorithm was applied to images from an ex vivo specimen of a porcine vertebra and successfully identified most of the growth plate (> 75%) amidst the osseous tissue of the vertebral body and the intervertebral disk. This master's project shows that OCT presents contrast, resolution and penetration depth that are sufficient for the identification of musculoskeletal structures of the spine. It is thus reasonable to believe that, ultimately, OCT could be used for the intraoperative guiding of the insertion of micro-staples during corrective surgeries of scoliosis.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Williams, G.
USDA economists predict the end of surplus farm production in the US within this decade. More and more marginal land will be cropped to provide feed for the growing world population and to produce energy. Much of this potential cropland in Southern Appalachia is poorly suited to annual crops, such as corn. Perennial crops are much better suited to steep, rocky, and wet sites. Research was undertaken on the theoretical potentials of perennial species with high predicted yields of protein, carbohydrates, or oils. Several candidate staple perennial crops for marginal land in Southern Appalachia were identified, and estimates were mademore » of their yields, energy input requirements, and general suitabilities. Cropping systems incorporating honeylocust, persimmon, mulberry, jujube, and beech were compared with corn cropping systems. It appears that these candidate staple perennials show distinct advantages for energy conservation and environmental preservation. Detailed economic analyses must await actual demonstration trials, but preliminary indications for ethanol conversion systems with honeylocust are encouraging. It is suggested that short-term loans to farmers undertaking this new type of agriculture would be appropriate to solve cash-flow problems.« less
Suzanne Fisher Staples: From Journalist to Novelist.
ERIC Educational Resources Information Center
Greever, Ellen A.; Austin, Patricia
1997-01-01
Presents the story of Suzanne Fisher Staples, author of the Newbery Honor Book, "Shabanu: Daughter of the Wind." States that she was first a journalist who experienced different foreign cultures firsthand, which provided the background for the novel. Discusses the difference between writing for newspapers and writing fiction. (PA)
Rural Inservice Education: Staples Teacher Center Style.
ERIC Educational Resources Information Center
Krueger, Rick
In its two-year existence, the federally funded Staples Teacher Center (STC) in Minnesota has had a significant impact on improving classroom instruction and staff development activities in a rural setting, proving that teacher centers are a most effective delivery system for inservice education in sparsely populated areas. Services are rendered…
Genome-wide association mapping of provitamin A carotenoid content in cassava
USDA-ARS?s Scientific Manuscript database
Global efforts are underway to develop staple crops with improved levels of provitamin A carotenoids to help combat dietary vitamin A deficiency, which is widespread among resource-poor farmers in the developing world. As a staple crop for more than 500 million people in sub-Saharan Africa, cassava ...
Extra long staple upland cotton for the production of superior yarn
USDA-ARS?s Scientific Manuscript database
Cotton, Gossypium spp., fibers are produced primarily by two species, G. hirsutum L., upland, and G. barbadense L., pima, which also is referred to as Extra Long Staple (ELS). The Cotton Improvement Laboratory, Texas AgriLife Research, has developed ELS upland lines through intraspecific crosses and...
ERIC Educational Resources Information Center
Lund, Duane R.
1977-01-01
Describes the case of Staples, Minnesota, where the vocational-technical school bought a 300-acre farm and with the help of a strong advisory committee was instrumental in changing the farming practices in an eight-county area. Emphasis is on the role and activities of the advisory committee; eleven specific contributions are listed. (HD)
7 CFR 1427.160 - Applicability.
Code of Federal Regulations, 2010 CFR
2010-01-01
.... (a) This subpart is applicable to the 2008 through 2012 crops of upland and extra long staple seed... for upland cotton and the national average loan rate for extra long staple cotton. (c) A producer must...) Loans shall not be available for seed cotton produced on land owned or otherwise in the possession of...
2013-01-01
Background Despite growing interest in use of lipid nutrient supplements for preventing child malnutrition and morbidity, there is inconclusive evidence on the effectiveness, and no evidence on the cost-effectiveness of this strategy. Methods A cost effectiveness analysis was conducted comparing costs and outcomes of two arms of a cluster randomized controlled trial implemented in eastern Chad during the 2010 hunger gap by Action contre la Faim France and Ghent University. This trial assessed the effect on child malnutrition and morbidity of a 5-month general distribution of staple rations, or staple rations plus a ready-to-use supplementary food (RUSF). RUSF was distributed to households with a child aged 6–36 months who was not acutely malnourished (weight-for-height > = 80% of the NCHS reference median, and absence of bilateral pitting edema), to prevent acute malnutrition in these children. While the addition of RUSF to a staple ration did not result in significant reduction in wasting rates, cost-effectiveness was assessed using successful secondary outcomes of cases of diarrhea and anemia (hemoglobin <110 g/L) averted among children receiving RUSF. Total costs of the program and incremental costs of RUSF and related management and logistics were estimated using accounting records and key informant interviews, and include costs to institutions and communities. An activity-based costing methodology was applied and incremental costs were calculated per episode of diarrhea and case of anemia averted. Results Adding RUSF to a general food distribution increased total costs by 23%, resulting in an additional cost per child of 374 EUR, and an incremental cost per episode of diarrhea averted of 1,083 EUR and per case of anemia averted of 3,627 EUR. Conclusions Adding RUSF to a staple ration was less cost-effective than other standard intervention options for averting diarrhea and anemia. This strategy holds potential to address a broad array of health and nutrition outcomes in emergency settings where infrastructure is weak and other intervention options are infeasible in the short-term. However, further research is needed to establish the contexts in which RUSF is most effective and cost-effective in preventing acute malnutrition and morbidity among vulnerable children, compared to other options. PMID:24210058
Evaluating the synchronicity in yield variations of staple crops at global scale
NASA Astrophysics Data System (ADS)
Yokozawa, M.
2014-12-01
Reflecting the recent globalization trend in world commodity market, several major production countries are producing large amount of staple crops, especially, maize and soybean. Thus, simultaneous crop failure (abrupt reduction in crop yield, lean year) due to extreme weather and/or climate change could lead to unstable food supply. This study try to examine the synchronicity in yield variations of staple crops at global scale. We use a gridded crop yields database, which includes the historical year-to-year changes in staple crop yields with a spatial resolution of 1.125 degree in latitude/longitude during a period of 1982-2006 (Iizumi et al. 2013). It has been constructed based on the agriculture statistics issued by local administrative bureaus in each country. For the regions being lack of data, an interpolation was conducted to obtain the values referring to the NPP estimates from satellite data as well as FAO country yield. For each time series of the target crop yield, we firstly applied a local kernel regression to represent the long-term trend component. Next, the deviations of yearly yield from the long-term trend component were defined as ΔY(i, y) in year y at grid i. Then, the correlation of deviation between grids i and j in year y is defined as Cij(y) = ΔY(i, y) ΔY(j, y). In addition, Pij = <ΔY(i, y) ΔY(j, y)> represents the time-averaged correlation of deviation between grids i and j. Bracket <...> means the time average operation over 25 years (1982-2006). As the results, figures show the time changes in the number of grid pairs, in which both the deviation are negative. It represent the time changes in ratio of the grid pairs where both crop yields synchronically decreased to the total grid pairs. The years denoted by arrows in the figures indicate the case that all the ratios of three country pairs (i.e. China-USA, USA-Brazil and Brazil-China) are relatively larger (>0.6 for soybean and >0.5 for maize). This suggests that the reductions in crop yield occurred synchronically in three countries in these years, which are the simultaneous lean years (as of lower yield compared to that of long-term trend).
Use of disposable stapler in operative cystogastrostomy for pancreatic pseudocyst.
Yunoki, Y; Takeuchi, H; Yasui, Y; Tanakaya, K; Konaga, E; Hamazaki, K
1999-01-01
Surgical stapling techniques are widely used in gastrointestinal surgery. These procedures are excellent in convenience and safety. We describe here a new practical application of the surgical disposable stapler, Auto Suture Premium Plus CEEA 34 circular stapler, for the operative drainage of a large symptomatic pancreatic pseudocyst. A 68 year-old man underwent an operative cystogastrostomy using this instrument. His post-operative recovery was uneventful. He is free from symptoms, and abdominal tomography shows complete disappearance of the cystic cavity. We believe that this is the first clinical paper that reports on the stapled cystogastrostomy. This instrument is very useful for creating a stapled cystogastrostomy, similar to one created in the standard open approach.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-28
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-905] Certain Polyester Staple... Preliminary Results of the 2011-2012 administrative review of the antidumping duty order on certain polyester... dumping margin is listed in the ``Final Results of Review'' section below. \\1\\ See Certain Polyester...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-28
... antidumping duty orders on Certain Polyester Staple Fiber from the People's Republic of China with respect to... Certain Polyester Staple Fiber from the People's Republic of China with respect to two exporters and on... exporter. Period to be reviewed Antidumping Duty Proceedings Japan: Certain Large Diameter Carbon and Alloy...
7 CFR 28.301 - Measurement: humidity; temperature.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 7 Agriculture 2 2014-01-01 2014-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...
7 CFR 28.301 - Measurement: humidity; temperature.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 2 2011-01-01 2011-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...
7 CFR 28.301 - Measurement: humidity; temperature.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 2 2010-01-01 2010-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70° F. ...
7 CFR 28.301 - Measurement: humidity; temperature.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 2 2012-01-01 2012-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...
7 CFR 28.301 - Measurement: humidity; temperature.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 2 2013-01-01 2013-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...
Seo, Su Hyun; Kim, Ki Han; Kim, Min Chan; Choi, Hong Jo; Jung, Ghap Joong
2012-06-01
Mechanical stapler is regarded as a good alternative to the hand sewing technique, when used in gastric reconstruction. The circular stapling method has been widely applied to gastrectomy (open orlaparoscopic), for gastric cancer. We illustrated and compared the hand-sutured method to the circular stapling method, for Billroth-II, in patients who underwent laparoscopy assisted distal gastrectomy for gastric cancer. Between April 2009 and May 2011, 60 patients who underwent laparoscopy assisted distal gastrectomy, with Billroth-II, were enrolled. Hand-sutured Billroth-II was performed in 40 patients (manual group) and circular stapler Billroth-II was performed in 20 patients (stapler group). Clinicopathological features and post-operative outcomes were evaluated and compared between the two groups. Nosignificant differences were observed in clinicopathologic parameters and post-operative outcomes, except in the operation times. Operation times and anastomosis times were significantly shorter in the stapler group (P=0.004 and P<0.001). Compared to the hand-sutured method, the circular stapling method can be applied safely and more efficiently, when performing Billroth-II anastomosis, after laparoscopy assisted distal gastrectomy in patients with gastric cancer.
Improvement in error propagation in the Shack-Hartmann-type zonal wavefront sensors.
Pathak, Biswajit; Boruah, Bosanta R
2017-12-01
Estimation of the wavefront from measured slope values is an essential step in a Shack-Hartmann-type wavefront sensor. Using an appropriate estimation algorithm, these measured slopes are converted into wavefront phase values. Hence, accuracy in wavefront estimation lies in proper interpretation of these measured slope values using the chosen estimation algorithm. There are two important sources of errors associated with the wavefront estimation process, namely, the slope measurement error and the algorithm discretization error. The former type is due to the noise in the slope measurements or to the detector centroiding error, and the latter is a consequence of solving equations of a basic estimation algorithm adopted onto a discrete geometry. These errors deserve particular attention, because they decide the preference of a specific estimation algorithm for wavefront estimation. In this paper, we investigate these two important sources of errors associated with the wavefront estimation algorithms of Shack-Hartmann-type wavefront sensors. We consider the widely used Southwell algorithm and the recently proposed Pathak-Boruah algorithm [J. Opt.16, 055403 (2014)JOOPDB0150-536X10.1088/2040-8978/16/5/055403] and perform a comparative study between the two. We find that the latter algorithm is inherently superior to the Southwell algorithm in terms of the error propagation performance. We also conduct experiments that further establish the correctness of the comparative study between the said two estimation algorithms.
Management of staple line leaks after sleeve gastrectomy in a consecutive series of 378 patients.
Vix, Michel; Diana, Michele; Marx, Ludovic; Callari, Cosimo; Wu, Hurng-Sheng; Perretta, Silvana; Mutter, Didier; Marescaux, Jacques
2015-02-01
Laparoscopic sleeve gastrectomy (LSG) is gaining acceptance as a stand-alone bariatric procedure with proven efficacy on weight loss and obesity-related comorbidities. A specific and potentially severe complication of LSG is the staple line leak (SLL). Our aim was to report the SLL rate and its management in a prospective cohort of 378 LSGs. A total of 378 patients underwent LSG from July 2005 to July 2011. The gastric transection was performed by an initial 60 mm firing of 4.5 mm staples at the antrum and successive 60 mm firings of 3.5 mm staples at the gastric body and fundus toward the left diaphragmatic crus. A 36 Fr bougie was used to calibrate the gastric tube. The staple line was systematically reinforced with a partial-thickness running suture. The overall complications and SLL rate were 20/378 (5.29%) and 9/378 (2.38%), respectively. SLLs were managed by laparoscopic (n=2) or open (n=1) exploration, drainage and endoscopic self-expandable covered stent, computed tomography-guided percutaneous drainage (n=2), or a self-expandable covered stent alone (n=4). Medical support including total parenteral nutrition and adapted antibiotics was started in all patients. The combined treatment modalities were successful in all cases. SLL was the most common complication of LSG accounting for half of the overall complications. Percutaneous drainage and self-covered stents combined with antibiotics and parenteral nutrition are effective for SLL and should be proposed as first-line treatment in stable patients.
[Staple fixation for the treatment of hamate metacarpal joint injury].
Tang, Yang-Hua; Zeng, Lin-Ru; Huang, Zhong-Ming; Yue, Zhen-Shuang; Xin, Da-Wei; Xu, Can-Da
2014-03-01
To investigate the effcacy of the staple fixation for the treatment of hamate metacarpal joint injury. From May 2009 to November 2012,16 patients with hamate metacarpal joint injury were treated with staple fixation including 10 males and 6 females with an average age of 33.6 years old ranging from 21 to 57 years. Among them, 11 cases were on the fourth or fifth metacarpal base dislocation without fractures, 5 cases were the fourth or fifth metacarpal base dislocation with avulsion fractures of the back of hamatum. Regular X-ray review was used to observe the fracture healing, joint replacement and position of staple fixation. The function of carpometacarpal joint and metacarpophalangeal joint were evaluated according to ASIA (TAM) system evaluation method. All incision were healed well with no infection. All patients were followed up from 16 to 24 months with an average of (10.0 +/- 2.7) months. No dislocation recurred, the position of internal fixator was good,no broken nail and screw withdrawal were occurred. Five patients with avulsion fracture of the back of hamatum achieved bone healing. The function of carpometacarpal joint and metacarpophalangeal was excellent in 10 cases,good in 5 cases, moderate in 1 case. The application of the staple for the treatment of hamatometacarpal joint injury has the advantages of simple operation, small trauma, reliable fixation, early postoperative function exercise and other advantages, which is the ideal operation mode for hamatometacarpal joint injury.
Zhang, Zhiying; Goldsmith, Peter D; Winter-Nelson, Alex
2016-05-05
There have been successful interventions fortifying staple foods to mobilize micronutrients as well as agricultural efforts to raise yields of staple foods to increase food availability. Zambia serves as an interesting case study because since 1961 there has been a notable decline in the availability of animal source foods (ASFs) and pulses and a significant increase in the supply of cassava and vegetable oils. The shift in food availability was partly attributed to the agricultural success in high-yielding and drought-resistant varieties that made cassava and oil crops more affordable and readily available. In this research, we explore another policy strategy that involves ASF as a mechanism to help remedy micronutrient inadequacies in a population. A scenario modeling analysis compares the changes in the nutrient profile of the Zambian diet through adding either staple plant source foods (PSFs) or ASFs. The scenarios under study involve the addition of (1) 18 fl oz of whole cow's milk; (2) 60 g of beef, 30 g of chicken, and 5 g of beef liver; (3) milk plus meat; or (4) 83 g of maize flour, 123 g of cassava, and other staple PSF, that is, isocaloric to the "milk + meat" group. The findings alert program planners and policy makers to the value of increasing the availability, accessibility, and utilization of ASF to simultaneously address multiple nutrient deficiencies, as well as the nutrition challenges that remain when expanding the availability of plant-based staples. © The Author(s) 2016.
Curings, P; Vincent, P-L; Viard, R; Gir, P; Comparin, J-P; Voulliaume, D
2017-11-23
Local postoperative care and burn wound management can present with a certain degree of difficulty in the pediatric population. While the use of skin staples as a method of skin graft fixation is a well-known, rapid and simple method, their removal can be painful and may necessitate some sedation or even general anesthesia. We studied in this article the advantages and economic value of using the cyanoacrylate glue as a fixation method for skin grafts. A comparative study was carried out from 2012 to 2016. Hundred and eighteen infants with burns up to 5% of total body surface area were included in the study. Seventy-two infants had split thickness skin grafts fixed with skin staples. Forty-six infants had split thickness skin grafts fixed with cyanoacrylate glue. We compared the quality of graft, the sedation used during the first postoperative dressing, the length of hospital stay, the amount of glue used and the presence of complications. There is a difference between the two groups studied in terms of age and total burn surface area. The rate of graft take was 100% in both groups. The first postoperative dressing was carried out without the use of powerful analgesia in the cyanoacrylate group, while it was necessary to use general anesthesia in 64% of the skin staples group. The average length of stay in hospital after skin grafting was 4.9 days for the cyanoacrylate glue versus 6.5 days in the skin staples group. No complications were noted in the 2 groups. The use of cyanoacrylate glue allows rapid fixation of skin grafts and avoid general anesthesia for postoperative cares. Subsequently the length of hospital stay is reduced within 25%. The medico-economic value of glue protocol is highly significant compared to skin staples, while having similar good results and without significant problems. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
[Does the third staple line of a new endostapler offer an advantage?].
Czymek, R; Keller, R; Hildebrand, P; Bouchard, R; Bader, F G; Jungbluth, T; Mirow, L; Roblick, U J; Bruch, H-P
2009-06-01
In laparoscopic colon surgery, endostaplers generate 2 parallel rows of staples. The aim of this paper is to analyse whether the introduction of a new endostapler generating a third row of staples influences the rate of anastomotic leakage and bleedings. 362 patients of the Department of Surgery, University Clinic of Schleswig-Holstein, Campus Lübeck, were included in this study. All patients underwent colon resection with performance of double-stapling anastomosis. In Group I (n = 148; 7 / 2004 to 12 / 2005), the Endopath TSB 45 endostapler (2 rows of staples) was used, whereas in Group II (n = 214; 7 / 2006 to 12 / 2007), the Echelon60 EC60 stapler (3 rows of staples) was used. All further operational steps were identical for both groups. Target parameters were the postoperative anastomotic leakage and anastomotic bleeding rates. Between July 2004 and December 2005, the number of anastomotic leaks (Stapler Endopath, TSB 45) was n = 4 (2.7 %), for the second period (Stapler Echelon60 EC60), it was n = 9 (3.7 %) (not significant). Using the Endopath TSB 45 stapler, the number of anastomotic bleedings was n = 12 (8.1 %), and for the Echelon60 EC60 stapler, it was n = 8 (3.7 %) (p = 0.074; not significant). Within the 18-month period between July 2006 and December 2007, the number of endoscopic colon operations (n = 214) rose by 44.6 % compared to the 18-month period between July 2004 and December 2005 (n = 148). The application of the advanced Echelon endostapler has no impact on the number of anastomotic leaks, and reduces the number of anastomotic bleedings slightly but not significantly. The increased number of endoscopic procedures in the second period results both from the growing number of indications for the application of endoscopic techniques and the positive findings of recent studies carried out by our own and other working groups.
Keshavarz, Somayye; Ebrahimi, Afshin; Nikaeen, Mahnaz
2015-01-01
Aims: The aims of this study were to determine fluoride concentration in drinking water and staple foods consumed by residents of Dayyer port (Bushehr province, south of Iran) and to assess its health risk via human intake in 2013. Materials and Methods: Health risk assessment due to fluoride exposure via consumption of drinking water, date, vegetables and fish was conducted in spring and summer of 2013 using the US-EPA (United States—Environmental Protection Agency) method, which considers hazard quotient (HQ) as a ratio of the estimated dose of a contaminant to the reference dose. A fluoride ion-selective electrode (ISE) measured the fluoride contents of food samples. The sodium-2-(parasulfophenyl largo)-1,8-dihydroxy-3,6-naphtnalene disulfonate colorimetric method (SPADNS) was used to determine fluoride concentration in water samples. Results: The total estimated oral intake of fluoride for children in summer and spring were 120.6 and 145.6 µg/kg/day, respectively. These values for adults were 99.2 and 112 µg/kg/day. This survey demonstrated that drinking water was the most important contributor of dietary fluoride intake in the study area. Conclusion: HQ values for adults and children were >1 which approves that a potential health risk of fluorosis can exist. The recommendations for the study area are supplying drinking water from alternative sources and defluoridation of drinking water by an adsorption technique and membrane filtration, respectively. Furthermore, people are suggested to have a good nutrition (especially rich of vitamin C) to reduce the risk of fluorosis. PMID:27462614
Keshavarz, Somayye; Ebrahimi, Afshin; Nikaeen, Mahnaz
2015-01-01
The aims of this study were to determine fluoride concentration in drinking water and staple foods consumed by residents of Dayyer port (Bushehr province, south of Iran) and to assess its health risk via human intake in 2013. Health risk assessment due to fluoride exposure via consumption of drinking water, date, vegetables and fish was conducted in spring and summer of 2013 using the US-EPA (United States-Environmental Protection Agency) method, which considers hazard quotient (HQ) as a ratio of the estimated dose of a contaminant to the reference dose. A fluoride ion-selective electrode (ISE) measured the fluoride contents of food samples. The sodium-2-(parasulfophenyl largo)-1,8-dihydroxy-3,6-naphtnalene disulfonate colorimetric method (SPADNS) was used to determine fluoride concentration in water samples. The total estimated oral intake of fluoride for children in summer and spring were 120.6 and 145.6 µg/kg/day, respectively. These values for adults were 99.2 and 112 µg/kg/day. This survey demonstrated that drinking water was the most important contributor of dietary fluoride intake in the study area. HQ values for adults and children were >1 which approves that a potential health risk of fluorosis can exist. The recommendations for the study area are supplying drinking water from alternative sources and defluoridation of drinking water by an adsorption technique and membrane filtration, respectively. Furthermore, people are suggested to have a good nutrition (especially rich of vitamin C) to reduce the risk of fluorosis.
Sutton, Nadia; Schmitz, Niels-Derrek; Johnston, Stephen S
2018-04-01
To compare economic and clinical outcomes between skin staples and 2-octyl cyanoacrylate plus polymer mesh tape, Dermabond Prineo skin closure system, (SCS) among patients undergoing total knee replacement (TKR). Retrospective, observational study using the Premier Healthcare Database, which comprises hospital administrative and billing data for over 700 hospitals in the US. Patients selected for study had an elective hospital admission, with discharge occurring between January 2012 and September 2015, carrying primary ICD-9-CM procedure and diagnosis codes for TKR and osteoarthritis. Patients were classified into two mutually-exclusive groups based on billing records during the index admission: those with billing record(s) for the skin closure system (SCS group); and those with billing record(s) for skin staples (staple group). Primary outcomes were index admission's length of stay (LOS), total hospital costs, and discharge status (skilled nursing facility (SNF)/other versus home/home health-care); exploratory outcomes included operating room time (ORT) during index admission and 30, 60, and 90-day readmissions. The SCS and staple groups were propensity score matched (1:1/nearest neighbour/caliper=0.10) on patient, hospital, and provider characteristics. Multivariable regressions accounting for hospital-level clustering after matching were used to compare outcomes between study groups. Each group comprised 971 patients (1942 total patients; mean age: 65.3 years; female: 63.5%). The groups were generally well-balanced on matching covariates: mean standardised difference calculated across 49 covariates=0.049. Compared with the staple group, the SCS group had statistically significant shorter LOS (2.8 days versus 3.2 days, p=0.002), lower rate of discharge to SNF/other versus home/home health-care (26.4% versus 38.5%, p=0.011), and lower rate of 30, 60, and 90-day readmissions (30-day, 1.8% versus 4.4%, p=0.006; 60-day, 3.0% versus 5.4%, p<0.001; 90-day, 5.4% versus 7.4%, p=0.016). Differences between the groups for other outcomes were not statistically significant. Among patients undergoing TKR, use of the SCS was associated with shorter LOS, less resource intensive discharge status, and lower rates of all-cause readmission as compared with skin staples.
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... DEPARTMENT OF COMMERCE International Trade Administration [A-580-839, A-583-833] Certain Polyester... sunset reviews of the antidumping duty orders on polyester staple fiber (PSF) from the Republic of Korea... polyesters measuring 3.3 decitex (3 denier, inclusive) or more in diameter. This merchandise is cut to...
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... Fiber From the People's Republic of China: Final Results of Antidumping Duty Administrative Review; 2010... staple fiber (``PSF'') from the People's Republic of China (``PRC'').\\1\\ We gave interested parties an opportunity to comment on the Preliminary Results. Based upon our analysis of the comments and information...
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... Fiber From the People's Republic of China: Preliminary Results and Rescission in Part of the 2011-2012... administrative review of the antidumping duty order on certain polyester staple fiber from the People's Republic... Industries (``Far Eastern'') and Huvis Sichuan Chemical Fiber Corp. and Huvis Sichuan Polyester Fiber Ltd...
USDA-ARS?s Scientific Manuscript database
Biofortification of staple crops to increase provitamin A carotenoids is a promising technique to alleviate vitamin A deficiency. ß-Carotene (ßC) and ß-cryptoxanthin (ßCX) are low in typical maize but higher in biofortified varieties. In vitro screening methods evaluate bioaccessibility of carotenoi...
[Local recurrence following anterior rectum resection--manual versus stapler suture].
Metzger, U; Weber, W; Weber, E; Linggi, J; Buchmann, P; Largiadèr, F
1985-04-01
A retrospective study was carried out on 88 hand sewn and 34 stapled anastomoses following anterior resection to evaluate the impact of suture technique on local recurrence rate. The patient groups were comparable with one exception: there were significantly more Dukes C lesions resected and sutured using the stapling gun (35% versus 15%, X2 = 6.33, p less than 0.05). Stage-corrected recurrence rate was similar in both groups, Dukes A: 8%, Dukes B 21%, Dukes C 52%, all recurrences being detected within 24 months following operation. Significantly fewer protective colostomies were needed using the staple gun (15% versus 34%, X2 = 4.50, p less than 0.05). Otherwise, no significant difference or benefit was observed comparing the two suture techniques.
[Stapler and manual bronchial anastomosis--results of a consecutive trial series].
Junginger, T; Walgenbach, S; Pichlmaier, H
1989-01-01
After lobectomy and pneumonectomy in experimental evaluations stapled bronchial closures showed the lowest incidence of inflammatory reaction and the highest strength determined by leakage pressure compared with other suture material. A total of 233 lung resections-performed at Surgical University Clinic Köln-Lindenthal and the Clinic for General and Abdominal Surgery of the Johannes-Gutenberg-Universität Mainz--were reviewed. Mechanical stapling reduced the rate of bronchopleural fistulas to 2.0% compared with 7.1% after manual suturing. In parallel, mortality related to bronchial stump leakage decreased to 0.7%. Main advantages of bronchial closure with staplers are the simplicity of their use, the speed and the uniformity of the closure. Thereby stapling devices are valuable completions in pulmonary surgery.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wells, J; Zhang, L; Samei, E
Purpose: To develop and validate more robust methods for automated lung, spine, and hardware detection in AP/PA chest images. This work is part of a continuing effort to automatically characterize the perceptual image quality of clinical radiographs. [Y. Lin et al. Med. Phys. 39, 7019–7031 (2012)] Methods: Our previous implementation of lung/spine identification was applicable to only one vendor. A more generalized routine was devised based on three primary components: lung boundary detection, fuzzy c-means (FCM) clustering, and a clinically-derived lung pixel probability map. Boundary detection was used to constrain the lung segmentations. FCM clustering produced grayscale- and neighborhood-based pixelmore » classification probabilities which are weighted by the clinically-derived probability maps to generate a final lung segmentation. Lung centerlines were set along the left-right lung midpoints. Spine centerlines were estimated as a weighted average of body contour, lateral lung contour, and intensity-based centerline estimates. Centerline estimation was tested on 900 clinical AP/PA chest radiographs which included inpatient/outpatient, upright/bedside, men/women, and adult/pediatric images from multiple imaging systems. Our previous implementation further did not account for the presence of medical hardware (pacemakers, wires, implants, staples, stents, etc.) potentially biasing image quality analysis. A hardware detection algorithm was developed using a gradient-based thresholding method. The training and testing paradigm used a set of 48 images from which 1920 51×51 pixel{sup 2} ROIs with and 1920 ROIs without hardware were manually selected. Results: Acceptable lung centerlines were generated in 98.7% of radiographs while spine centerlines were acceptable in 99.1% of radiographs. Following threshold optimization, the hardware detection software yielded average true positive and true negative rates of 92.7% and 96.9%, respectively. Conclusion: Updated segmentation and centerline estimation methods in addition to new gradient-based hardware detection software provide improved data integrity control and error-checking for automated clinical chest image quality characterization across multiple radiography systems.« less
Novel angle estimation for bistatic MIMO radar using an improved MUSIC
NASA Astrophysics Data System (ADS)
Li, Jianfeng; Zhang, Xiaofei; Chen, Han
2014-09-01
In this article, we study the problem of angle estimation for bistatic multiple-input multiple-output (MIMO) radar and propose an improved multiple signal classification (MUSIC) algorithm for joint direction of departure (DOD) and direction of arrival (DOA) estimation. The proposed algorithm obtains initial estimations of angles obtained from the signal subspace and uses the local one-dimensional peak searches to achieve the joint estimations of DOD and DOA. The angle estimation performance of the proposed algorithm is better than that of estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm, and is almost the same as that of two-dimensional MUSIC. Furthermore, the proposed algorithm can be suitable for irregular array geometry, obtain automatically paired DOD and DOA estimations, and avoid two-dimensional peak searching. The simulation results verify the effectiveness and improvement of the algorithm.
Ruiz-Tovar, Jaime; Muñoz, Jose Luis; Gonzalez, Juan; Garcia, Alejandro; Ferrigni, Carlos; Jimenez, Montiel; Duran, Manuel
2017-12-01
The performance of most bariatric procedures within an Enhanced Recovery After Surgery program has resulted in significant advantages, including a reduction in the length of hospital stay to 2-3 days. However, some postoperative complications may appear after the patient has been discharged. The aim of this study was to investigate the efficacy of various acute-phase parameters determined 24 h after a laparoscopic sleeve gastrectomy for predicting staple line leak in the postoperative course. A prospective study of 208 morbidly obese patients undergoing laparoscopic sleeve gastrectomy as bariatric procedure between 2012 and 2015 was performed. Blood analysis was performed 24 h after surgery. Acute-phase parameters (C-reactive protein, procalcitonin, fibrinogen, and White Blood Cell count) were investigated. Staple line leak appeared in eight patients (3.8%). Using receiver operating characteristic analysis at 24 h postoperatively, a cutoff level of CRP at 9 mg/dL achieved 85% sensitivity and 90% specificity for predicting staple line leak, a cutoff level of procalcitonin at 0.85 ng/mL achieved 70% sensitivity and 90% specificity, and a cutoff level of fibrinogen at 600 mg/dL achieved 80% sensitivity and 87.5% specificity. An elevation of CRP > 9 mg/dL, procalcitonin > 0.85 ng/mL and fibrinogen > 600 mg/dL should alert the surgeon the possibility of occurrence of postoperative staple line leak.
Fegelman, Elliott; Knippenberg, Susan; Schwiers, Michael; Stefanidis, Dimitrios; Gersin, Keith S; Scott, John D; Fernandez, Adolfo Z
2017-05-01
Transection of gastric tissue during laparoscopic sleeve gastrectomy (LSG) can be challenging. Reinforcing the staple line may decrease the incidence of issues requiring intervention. The objective of this study was to compare the number of intraoperative surgical interventions for a surgical stapler and reload system with Gripping Surface Technology (GST) to standard reloads in patients who underwent LSG. Patients who underwent elective LSG were enrolled. The study was conducted in two stages. For Stage 1, procedures were performed using a powered stapler and standard reloads. For Stage 2, a reload system with GST was used. The primary endpoint was surgical interventions for bleeding and/or staple line issues during transection of the greater curvature of the stomach. Propensity score matching was applied to create two groups similar in baseline characteristics and risk factors. A total of 111 subjects were enrolled across four centers. Propensity-matched procedures were completed with the standard (n = 38) or GST reloads (n = 38). The mean number of interventions in the standard group was 1.9 (1.29) versus 1.1 (1.45) in the GST group. Nonparametric comparisons were statistically significant, indicating a reduction in the distribution of interventions for GST subjects (P = .0036 for matched pair data). Tissue slippage during transection was low for both groups. Intraoperative leak testing was negative in all procedures, and no procedures were converted to open. Use of the GST stapling system reduces the need for staple line interventions in LSG. Both stapling systems had an acceptable safety profile.
Gagner, Michel; Huang, Rose Y
2016-04-01
Placement of a bougie for sleeve sizing during laparoscopic sleeve gastrectomy (LSG) is recommended. We compared this standard with a suction calibration system (SCS) that performs all functions with one insertion, and measured each step's duration. Primary LSG was performed using a bougie and SCS in alternating order. Number of tube movements to achieve optimal placement, durations of decompression, leak testing, and overall operative time, and remnant linear measurements were obtained. LSG was performed in 26 patients (15 women, 11 men; mean age 36.8 years; mean BMI 45.3 kg/m(2)). The mean number of tube movements was significantly greater for the bougie than for the SCS (8.13 vs. 3.58; p < 0.0001). Percent reductions achieved using the SCS were: time to full decompression of the stomach, 62% (21 vs. 8 s; p < 0.138); tube placement, 51% (101 vs. 49 s; p < 0.0001); leak testing, 78% (119 vs. 26 s; p < 0.0003); and mean operative duration (from tube insertion to end of stapling), 21% (875 vs. 697 s; p < 0.019). Variance of the staple-line distance, measured from the greater curvature to the staple line, was 1.64 and 0.92 for the bougie and SCS, respectively, indicating a reduction in corkscrewing, for a 43.9% straighter sleeve. SCS maintained the gastric wall in place, thereby preventing corkscrewing, and reducing total operating time. Reducing the number of tube insertions may prevent esophageal damage and accidental tube stapling.
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... orders on Certain Polyester Staple Fiber from the People's Republic of China (``PRC'') with respect to... Diameter Carbon and Alloy Seamless, 6/1/09-5/31/10 Standard, Line, and Pressure Pipe, A-588-850.... JFE... Republic of China: Certain Polyester Staple Fiber, \\3\\ A-570-905.... 6/1/09-5/31/10 Far Eastern Industries...
The tissue-selecting technique: segmental stapled hemorrhoidopexy.
Lin, Hong-Cheng; Lian, Lei; Xie, Shang-Kui; Peng, Hui; Tai, Jian-Dong; Ren, Dong-Lin
2013-11-01
We describe a technique for the management of prolapsing hemorrhoids, with the aim to minimize the risk of anal stricture and rectovaginal fistula and to reduce the impact of the stapling technique on rectal compliance. This modified procedure was successfully applied in China, and preliminary data showed promising outcomes (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A117).
Evaluation of the ViSiGiTM Calibration System
2013-12-10
Enhance Delineation of the Stomach Anatomy and the Surgeon's Appreciation of the Extent of Gastric Volume to be Removed;; Increase the Safety Profile of the Patient (i.e., Reduce the Likelihood of Accidental Stapling of the Orogastric Tube or Bougie);; Reduce the Incidence of OR Contamination/Infection Transmission;; Streamline OR Workflow, Resulting in Reduced OR Time; Ensure Consistent and Reproducible Staple Lines.
Levionnois, Olivier L; Bergadano, Alessandra; Schatzmann, Urs
2006-01-01
To describe the use of an endobronchial blocker (EBB) and to perform selective ventilation during pulmonary lobe resection via thoracotomy in a dog and report its accidental stapling in the resection site. Clinical case report. One female dog with a suspected abscess or neoplasia of the right caudal pulmonary lobe. One-lung ventilation was performed using a wire-guided EBB to seal the contaminated parenchyma and facilitate surgical access. The affected lung parenchyma was resected and the resection site was closed with staples. Lobar resection was performed successfully, but the loop of the EBB guide wire was inadvertently entrapped in the staple line of the lobectomy. Staples were removed to release the wire loop, and the resulting air leak caused loss of ventilation control until the parenchyma was re-sealed. We recommend removing the wire guide associate with the EBB after successful lung separation to avoid accidents that could have life-threatening consequences if not recognized. One-lung ventilation is useful to isolate healthy parenchyma from diseased parenchyma during lobectomy. Anesthesiologists and surgeons need to be aware of the potential complications associated with use of EBB.
Seo, Su Hyun; Kim, Min Chan; Choi, Hong Jo; Jung, Ghap Joong
2012-01-01
Purpose Mechanical stapler is regarded as a good alternative to the hand sewing technique, when used in gastric reconstruction. The circular stapling method has been widely applied to gastrectomy (open orlaparoscopic), for gastric cancer. We illustrated and compared the hand-sutured method to the circular stapling method, for Billroth-II, in patients who underwent laparoscopy assisted distal gastrectomy for gastric cancer. Materials and Methods Between April 2009 and May 2011, 60 patients who underwent laparoscopy assisted distal gastrectomy, with Billroth-II, were enrolled. Hand-sutured Billroth-II was performed in 40 patients (manual group) and circular stapler Billroth-II was performed in 20 patients (stapler group). Clinicopathological features and post-operative outcomes were evaluated and compared between the two groups. Results Nosignificant differences were observed in clinicopathologic parameters and post-operative outcomes, except in the operation times. Operation times and anastomosis times were significantly shorter in the stapler group (P=0.004 and P<0.001). Conclusions Compared to the hand-sutured method, the circular stapling method can be applied safely and more efficiently, when performing Billroth-II anastomosis, after laparoscopy assisted distal gastrectomy in patients with gastric cancer. PMID:22792525
Use of the stapler in anterior resection for cancer of the rectosigmoid.
Resnick, S D; Burstein, A E; Viner, Y L
1983-02-01
The circular stapling device was used for anterior resection in 61 of 88 patients who underwent curative surgery for rectosigmoid cancer. Use of the autosuture increased the success rate to 68.5% for this radical sphincter-saving procedure. In three-quarters of the patients the stapling end-to-end inverting colorectal anastomosis was created within 3 to 8 cm from the dentate line, where it is difficult or even impossible to perform anastamoses by the conventional manual technique. Anastomotic leakage (3.3%) and hemorrhage (4.9%), mild anastomotic stenosis (1.6%) and transitory anal incontinence (4.9%) were the main complications. There were no deaths in our series. The great safety of the stapling anastomosis and the low rate of anal incontinence may be explained by the preservation of an adequate blood supply and innervation of the rectal stump and its sphincter apparatus, as the stapling device needs only minimal mobilization of the bowel involved in the anastomosis. Restoring colorectal continuity after Hartmann's resection is a speedy, safe and simple procedure with the EEA (enteroenterostomy) stapler. Hartmann's operation may thus be considered the procedure of choice in emergency surgery for obstructed rectosigmoid cancer.
Staple Food Self-Sufficiency of Farmers Household Level in The Great Solo
NASA Astrophysics Data System (ADS)
Darsono
2017-04-01
Analysis of food security level of household is a novelty of measurement standards which usually includes regional and national levels. With household approach is expected to provide the basis of sharp food policy formulation. The purpose of this study are to identify the condition of self-sufficiency in staple foods, and to find the main factors affecting the dynamics of self-sufficiency in staple foods on farm household level in Great Solo. Using primary data from 50 farmers in the sample and secondary data in Great Solo (Surakarta city, Boyolali, Sukoharjo, Karanganyar, Wonogiri, Sragen and Klaten). Compiled panel data were analyzed with linear probability regression models to produce a good model. The results showed that farm households in Great Solo has a surplus of staple food (rice) with an average consumption rate of 96.8 kg/capita/year. This number is lower than the national rate of 136.7 kg/capita/year. The main factors affecting the level of food self-sufficiency in the farmer household level are: rice production, rice consumption, land tenure, and number of family members. Key recommendations from this study are; improvement scale of the land cultivation for rice farming and non-rice diversification consumption.
A comparison of kinematic algorithms to estimate gait events during overground running.
Smith, Laura; Preece, Stephen; Mason, Duncan; Bramah, Christopher
2015-01-01
The gait cycle is frequently divided into two distinct phases, stance and swing, which can be accurately determined from ground reaction force data. In the absence of such data, kinematic algorithms can be used to estimate footstrike and toe-off. The performance of previously published algorithms is not consistent between studies. Furthermore, previous algorithms have not been tested at higher running speeds nor used to estimate ground contact times. Therefore the purpose of this study was to both develop a new, custom-designed, event detection algorithm and compare its performance with four previously tested algorithms at higher running speeds. Kinematic and force data were collected on twenty runners during overground running at 5.6m/s. The five algorithms were then implemented and estimated times for footstrike, toe-off and contact time were compared to ground reaction force data. There were large differences in the performance of each algorithm. The custom-designed algorithm provided the most accurate estimation of footstrike (True Error 1.2 ± 17.1 ms) and contact time (True Error 3.5 ± 18.2 ms). Compared to the other tested algorithms, the custom-designed algorithm provided an accurate estimation of footstrike and toe-off across different footstrike patterns. The custom-designed algorithm provides a simple but effective method to accurately estimate footstrike, toe-off and contact time from kinematic data. Copyright © 2014 Elsevier B.V. All rights reserved.
Orientation estimation algorithm applied to high-spin projectiles
NASA Astrophysics Data System (ADS)
Long, D. F.; Lin, J.; Zhang, X. M.; Li, J.
2014-06-01
High-spin projectiles are low cost military weapons. Accurate orientation information is critical to the performance of the high-spin projectiles control system. However, orientation estimators have not been well translated from flight vehicles since they are too expensive, lack launch robustness, do not fit within the allotted space, or are too application specific. This paper presents an orientation estimation algorithm specific for these projectiles. The orientation estimator uses an integrated filter to combine feedback from a three-axis magnetometer, two single-axis gyros and a GPS receiver. As a new feature of this algorithm, the magnetometer feedback estimates roll angular rate of projectile. The algorithm also incorporates online sensor error parameter estimation performed simultaneously with the projectile attitude estimation. The second part of the paper deals with the verification of the proposed orientation algorithm through numerical simulation and experimental tests. Simulations and experiments demonstrate that the orientation estimator can effectively estimate the attitude of high-spin projectiles. Moreover, online sensor calibration significantly enhances the estimation performance of the algorithm.
Shumeta, Zekarias; D'Haese, Marijke
2018-06-01
Most coffee in Ethiopia is produced by smallholder farmers who face a daily struggle to get sufficient income but also to feed their families. At the same time, many smallholder coffee producers are members of cooperatives. Yet, literature has paid little attention to the effect of cooperatives on combating food insecurity among cash crop producers including coffee farmers. The objective of the study was to investigate how coffee cooperative membership may affect food security among coffee farm households in Southwest Ethiopia. The study used cross-sectional household data on income, expenditure on food, staple food production (maize and teff), and utilization of improved inputs (fertilizer and improved seed) collected from 256 randomly selected farm households (132 cooperative members and 124 nonmembers) and applied an inverse probability weighting (IPW) estimation to assess the impact of cooperative membership on food security. The result revealed that cooperative membership has a positive and significant effect on staple food production (maize and teff) and facilitated technological transformation via increased utilization of fertilizer and improved seeds. Nonetheless, the effect on food expenditure and income could not be confirmed. Findings suggest a trade-off between coffee marketing and input supply functions of the cooperatives, impairing their true food security impact from the pooled income and production effect.
NASA Astrophysics Data System (ADS)
Alpatov, Boris; Babayan, Pavel; Ershov, Maksim; Strotov, Valery
2016-10-01
This paper describes the implementation of the orientation estimation algorithm in FPGA-based vision system. An approach to estimate an orientation of objects lacking axial symmetry is proposed. Suggested algorithm is intended to estimate orientation of a specific known 3D object based on object 3D model. The proposed orientation estimation algorithm consists of two stages: learning and estimation. Learning stage is devoted to the exploring of studied object. Using 3D model we can gather set of training images by capturing 3D model from viewpoints evenly distributed on a sphere. Sphere points distribution is made by the geosphere principle. Gathered training image set is used for calculating descriptors, which will be used in the estimation stage of the algorithm. The estimation stage is focusing on matching process between an observed image descriptor and the training image descriptors. The experimental research was performed using a set of images of Airbus A380. The proposed orientation estimation algorithm showed good accuracy in all case studies. The real-time performance of the algorithm in FPGA-based vision system was demonstrated.
The business case for transitioning to safer chemicals.
McFadden, Roger D
2011-01-01
Emerging domestic and international chemical regulations and a heightened consumer awareness of chemicals of concern in products is challenging American businesses to reevaluate and reconsider their approaches to supply chain management and product design. Some of these companies recognize business opportunities and are responding proactively with innovative strategies and tactics. This article describes steps that Staples Inc., the world's largest office products provider, is taking to meet demand for products that are safer and more sustainable. In trying to meet the demand for safer products, Staples faces significant barriers, including the complexity of supply chains, data gaps, and confidential business information. New collaborations between companies, government, and advocates, and improved tools and criteria for defining safer products enhance the ability of businesses, like Staples, to meet new consumer demands.
Baldini, Elizabeth H; Bosch, Walter; Kane, John M; Abrams, Ross A; Salerno, Kilian E; Deville, Curtiland; Raut, Chandrajit P; Petersen, Ivy A; Chen, Yen-Lin; Mullen, John T; Millikan, Keith W; Karakousis, Giorgos; Kendrick, Michael L; DeLaney, Thomas F; Wang, Dian
2015-09-01
Curative intent management of retroperitoneal sarcoma (RPS) requires gross total resection. Preoperative radiotherapy (RT) often is used as an adjuvant to surgery, but recurrence rates remain high. To enhance RT efficacy with acceptable tolerance, there is interest in delivering "boost doses" of RT to high-risk areas of gross tumor volume (HR GTV) judged to be at risk for positive resection margins. We sought to evaluate variability in HR GTV boost target volume delineation among collaborating sarcoma radiation and surgical oncologist teams. Radiation planning CT scans for three cases of RPS were distributed to seven paired radiation and surgical oncologist teams at six institutions. Teams contoured HR GTV boost volumes for each case. Analysis of contour agreement was performed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. HRGTV boost volume contour agreement between the seven teams was "substantial" or "moderate" for all cases. Agreement was best on the torso wall posteriorly (abutting posterior chest abdominal wall) and medially (abutting ipsilateral para-vertebral space and great vessels). Contours varied more significantly abutting visceral organs due to differing surgical opinions regarding planned partial organ resection. Agreement of RPS HRGTV boost volumes between sarcoma radiation and surgical oncologist teams was substantial to moderate. Differences were most striking in regions abutting visceral organs, highlighting the importance of collaboration between the radiation and surgical oncologist for "individualized" target delineation on the basis of areas deemed at risk and planned resection.
Schoenberg, Mike R; Lange, Rael T; Saklofske, Donald H
2007-11-01
Establishing a comparison standard in neuropsychological assessment is crucial to determining change in function. There is no available method to estimate premorbid intellectual functioning for the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). The WISC-IV provided normative data for both American and Canadian children aged 6 to 16 years old. This study developed regression algorithms as a proposed method to estimate full-scale intelligence quotient (FSIQ) for the Canadian WISC-IV. Participants were the Canadian WISC-IV standardization sample (n = 1,100). The sample was randomly divided into two groups (development and validation groups). The development group was used to generate regression algorithms; 1 algorithm only included demographics, and 11 combined demographic variables with WISC-IV subtest raw scores. The algorithms accounted for 18% to 70% of the variance in FSIQ (standard error of estimate, SEE = 8.6 to 14.2). Estimated FSIQ significantly correlated with actual FSIQ (r = .30 to .80), and the majority of individual FSIQ estimates were within +/-10 points of actual FSIQ. The demographic-only algorithm was less accurate than algorithms combining demographic variables with subtest raw scores. The current algorithms yielded accurate estimates of current FSIQ for Canadian individuals aged 6-16 years old. The potential application of the algorithms to estimate premorbid FSIQ is reviewed. While promising, clinical validation of the algorithms in a sample of children and/or adolescents with known neurological dysfunction is needed to establish these algorithms as a premorbid estimation procedure.
Coupled Inertial Navigation and Flush Air Data Sensing Algorithm for Atmosphere Estimation
NASA Technical Reports Server (NTRS)
Karlgaard, Christopher D.; Kutty, Prasad; Schoenenberger, Mark
2016-01-01
This paper describes an algorithm for atmospheric state estimation based on a coupling between inertial navigation and flush air data-sensing pressure measurements. The navigation state is used in the atmospheric estimation algorithm along with the pressure measurements and a model of the surface pressure distribution to estimate the atmosphere using a nonlinear weighted least-squares algorithm. The approach uses a high-fidelity model of atmosphere stored in table-lookup form, along with simplified models propagated along the trajectory within the algorithm to aid the solution. Thus, the method is a reduced-order Kalman filter in which the inertial states are taken from the navigation solution and atmospheric states are estimated in the filter. The algorithm is applied to data from the Mars Science Laboratory entry, descent, and landing from August 2012. Reasonable estimates of the atmosphere are produced by the algorithm. The observability of winds along the trajectory are examined using an index based on the observability Gramian and the pressure measurement sensitivity matrix. The results indicate that bank reversals are responsible for adding information content. The algorithm is applied to the design of the pressure measurement system for the Mars 2020 mission. A linear covariance analysis is performed to assess estimator performance. The results indicate that the new estimator produces more precise estimates of atmospheric states than existing algorithms.
Manifold absolute pressure estimation using neural network with hybrid training algorithm
Selamat, Hazlina; Alimin, Ahmad Jais; Haniff, Mohamad Fadzli
2017-01-01
In a modern small gasoline engine fuel injection system, the load of the engine is estimated based on the measurement of the manifold absolute pressure (MAP) sensor, which took place in the intake manifold. This paper present a more economical approach on estimating the MAP by using only the measurements of the throttle position and engine speed, resulting in lower implementation cost. The estimation was done via two-stage multilayer feed-forward neural network by combining Levenberg-Marquardt (LM) algorithm, Bayesian Regularization (BR) algorithm and Particle Swarm Optimization (PSO) algorithm. Based on the results found in 20 runs, the second variant of the hybrid algorithm yields a better network performance than the first variant of hybrid algorithm, LM, LM with BR and PSO by estimating the MAP closely to the simulated MAP values. By using a valid experimental training data, the estimator network that trained with the second variant of the hybrid algorithm showed the best performance among other algorithms when used in an actual retrofit fuel injection system (RFIS). The performance of the estimator was also validated in steady-state and transient condition by showing a closer MAP estimation to the actual value. PMID:29190779
Performance of Pallet Nails and Staples in 22 Southern Hardwoods
E.G. Stern
1976-01-01
The effectiveness of pointless, helically threaded, hardened-steel, 3 by O.120-inch, pallet nails with umbrella heads and 21/2-inch, 15-gauge, 7/16-inch crown, plastic-coated, pallet staples in 22 hardwoods grown on southern pine sites was determined on the basis of tests on 522 joints. Specific average performance values were derived from the test data for the tested...
Arroyo, Antonio; Pérez-Legaz, Juan; Miranda, Elena; Moya, Pedro; Ruiz-Tovar, Jaime; Lacueva, Francisco-Javier; Candela, Fernando; Calpena, Rafael
2011-05-01
The aim of this prospective controlled trial was to evaluate the long-term clinical and manometric results of stapled hemorrhoidopexy performed by expert surgeons in a selected group of patients for the treatment of chronic hemorrhoids. This study took place in the outpatient clinic and at the Day Surgery Unit attached to the University Hospital of Elche. From March 2003 to May 2005, 200 consecutive patients with third-degree hemorrhoids and treated with double-pursestring stapled hemorrhoidopexy with a PPH33-03 stapler were included in the study. Demographic, manometric, and clinical features were analyzed, as well as the variables related to surgery, postoperative course, and follow-up. Manometry was repeated at the 6-month, 1-year, and 5-year follow-up. Median follow-up was 110 months. Four patients (2%) reported daily rectal bleeding. One patient with active rectal bleeding was taken for reoperation within the first 12 postoperative hours. Seventy percent of patients reported pain ≤ 2 on the first postoperative day, 85% on the fourth postoperative day, and 95% on the seventh postoperative day. Pain was measured with a linear analog scale from 0 to 10 (0 = no pain; 10 = unbearable pain). Seventeen patients (8.5%) reported tenesmus during the first week. Eight patients (4%) reported persistent pain: in 5 patients, the pain resolved within the next 6 months; 2 patients presented with anal fissure; and 1 patient required the removal of the staples. Two patients (1%) reported residual soiling at the 5-year revision. Fourteen patients (7%) experienced recurrence with symptomatic prolapse. Six (3%) underwent further surgery: stapled hemorrhoidopexy was indicated again in 2 patients, and 4 patients underwent a Milligan-Morgan open hemorrhoidectomy, because they did not have a uniform prolapse. Six patients required treatment with rubber band ligation. There were no statistically significant differences between preoperative and postoperative manometric values. The new PPH33-03 stapler, the learning process of the modified surgical procedure, and the correct selection of patients will overcome the main objections to stapled hemorrhoidopexy.
Stapled haemorrhoidopexy transiently decreases rectal compliance and sensitivity.
Filho, F L A; Macedo, G M; Dos Santos, A A; Rodrigues, L V; Oliveira, R B; Nobre E Souza, M A
2011-02-01
Stapled haemorrhoidopexy may damage the anorectal musculature and its sensorimotor function. Most studies have not used a barostat for the measurement of compliance. This study aimed to investigate the effect of stapled haemorrhoidopexy on rectal compliance and sensitivity. After Ethical Committee approval, we studied 10 male patients (mean age 33.8 years) with third- or fourth-degree haemorrhoids. Rectal compliance and sensitivity were measured with a 600-ml bag and an electronic barostat. Volunteers were submitted to two consecutive rectal distension protocols, including continuous distension at 2, 4 and 6 months after stapled haemorrhoidopexy. Intraluminal volume and pressure were recorded, including the first rectal sensation, desire to defecate and onset of rectal pain. Another group of 10 male control patients (mean age 24.9 years) with pilonidal sinus and no haemorrhoids was also included in the study. Two months after stapled haemorrhoidopexy, rectal compliance decreased (7.1 ± 0.2 vs 5.3 ± 0.1, 6.4 ± 0.1 vs 5.1 ± 0.1 and 5.6 ± 0.2 vs 4.7 ± 0.1 ml/mmHg for first rectal sensation, desire to defecate and rectal pain, respectively; P < 0.05). The sensitivity threshold volume did not change for the first sensation but decreased significantly for the desier to defecate and pain (p <0.05) (116.8 ± 13.8 vs 148.4 ± 14.61, 251.1 ± 8.9 vs 185.8 ± 8.6 and 293.3 ± 16.6 vs 221.2 ± 6.0 ml for first rectal sensation, desire to defecate and rectal pain, respectively). Four and 6 months after surgery, rectal compliance and sensitivity returned to levels similar to those in the basal period. Muscle tissue was found in only three of the 10 resected doughnuts. Controls remained without any change in rectal compliance and sensitivity. Stapled haemorrhoidopexy transiently decreases rectal compliance and sensitivity threshold in young male patients. © 2010 The Authors. Colorectal Disease © 2010 The Association of Coloproctology of Great Britain and Ireland.
Space shuttle propulsion parameter estimation using optimal estimation techniques
NASA Technical Reports Server (NTRS)
1983-01-01
The first twelve system state variables are presented with the necessary mathematical developments for incorporating them into the filter/smoother algorithm. Other state variables, i.e., aerodynamic coefficients can be easily incorporated into the estimation algorithm, representing uncertain parameters, but for initial checkout purposes are treated as known quantities. An approach for incorporating the NASA propulsion predictive model results into the optimal estimation algorithm was identified. This approach utilizes numerical derivatives and nominal predictions within the algorithm with global iterations of the algorithm. The iterative process is terminated when the quality of the estimates provided no longer significantly improves.
Productivity of Rice Grown on Arsenic Contaminated Soil under a Changing Climate
NASA Astrophysics Data System (ADS)
Wang, T.; Plaganas, M.; Muehe, E. M.; Fendorf, S. E.
2016-12-01
Rice is the staple food for more than 50% of the global population. In South and Southeast Asia, native soil arsenic coupled with arsenic-laden irrigation water result in paddy soils having arsenic levels that decrease the quality and productivity of rice and thus compromise food security worldwide. However, it remains unknown how climate change will affect the accumulation of arsenic in rice plants, specifically grain, grown in arsenic-bearing paddy soils. We hypothesize that the bioavailability of arsenic in the paddy soil will increase with climate change leading to an even sharper decrease of rice productivity and quality than presently estimated. In order to shed light on this question, we performed greenhouse studies to simulate today's climate condition in Asian paddy soils and compare it to the conditions projected for the year 2100. We investigated climate conditions estimated in the 5th assessment report of the IPCC1, indicating up to a 5°C increase in temperature and doubled atmospheric CO2 concentrations. Under these current and future climate conditions, we examined rice physiology including plant height and biomass, leaf chlorophyll content, grain number and weight as well as contents of accumulated arsenic, and its species in the different rice tissues. We further correlate different geochemical parameters of the soil, including arsenic and other relevant metal dynamics in the soil, to plant response. In sum, our analyses will allow us to better predict the productivity of rice and its grain quality in a future climate condition, and may help to take precautions to avoid a global food crisis, particularly for South and Southeast Asia where rice is a daily staple. 1IPCC - Intergovernmental Panel on Climate Change, Climate Change 2013, The Physical Science Basis.
Markar, Sheraz R; Penna, Marta; Venkat-Ramen, Vishal; Karthikesalingam, Alan; Hashemi, Majid
2012-01-01
The aim of the present study was to provide a pooled analysis of individual small trials comparing 21-mm and 25-mm circular stapled laparoscopic gastrojejunal (GJ) anastomosis in morbid obesity surgery. A systematic literature search of MEDLINE, Embase, and Cochrane library databases was performed to identify all relevant studies comparing 21-mm and 25-mm circular stapled laparoscopic GJ anastomosis in morbid obesity surgery. The primary outcomes were GJ stenosis and the interval to GJ stenosis. The secondary outcomes were the estimated weight loss, GJ diameter, and the number of endoscopic dilations. Pooled odds ratios were calculated for categorical outcomes and weighted mean differences for continuous outcomes. Five trials were included, comprising 1217 patients (393 with 21-mm and 824 with 25-mm circular GJ anastomoses). The primary outcome analysis revealed a significantly increased incidence of intraluminal stenosis associated with the 21-mm circular stapler (pooled odds ratio 3.54; P < .0001). The secondary outcome analysis revealed a significantly reduced GJ anastomotic diameter on endoscopy with the 21-mm circular stapler group (weighted mean difference -1.67; P = .002). Statistical analysis revealed no significant difference between the groups for the interval to stenosis, number of endoscopic dilations, and estimated weight loss. The results of the present pooled analysis have demonstrated a significantly increased incidence of symptomatic stenosis associated with the 21-mm circular stapler compared with the 25-mm stapler. This serves as evidence to validate the preferential selection of the 25-mm circular stapler for laparoscopic GJ bypass. Copyright © 2012 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.
DeCamp, Malcolm M; Blackstone, Eugene H; Naunheim, Keith S; Krasna, Mark J; Wood, Douglas E; Meli, Yvonne M; McKenna, Robert J
2006-07-01
Although staple line buttressing is advocated to reduce air leak after lung volume reduction surgery (LVRS), its effectiveness is unknown. We sought to identify risk factors for air leak and its duration and to estimate its medical consequences for selecting optimal perioperative technique(s), such as buttressing technique, to preempt or treat post-LVRS air leak. Detailed air leak data were available for 552 of 580 patients receiving bilateral stapled LVRS in the National Emphysema Treatment Trial. Risk factors for prevalence and duration of air leak were identified by logistic and hazard function analyses. Medical consequences were estimated in propensity-matched pairs with and without air leak. Within 30 days of LVRS, 90% of patients developed air leak (median duration = 7 days). Its occurrence was more common and duration prolonged in patients with lower diffusing capacity (p = 0.06), upper lobe disease (p = 0.04), and important pleural adhesions (p = 0.007). Duration was also protracted in Caucasians (p < 0.0001), patients using inhaled steroids (p = 0.004), and those with lower 1-second forced expiratory volume (p = 0.0003). Surgical approach, buttressing, stapler brand, and intraoperative adjunctive procedures were not associated with fewer or less prolonged air leaks (p >/= 0.2). Postoperative complications occurred more often in matched patients experiencing air leak (57% vs 30%, p = 0.0004), and postoperative stay was longer (11.8 +/- 6.5 days vs 7.6 +/- 4.4 days, p = 0.0005). Air leak accompanies LVRS in 90% of patients, is often prolonged, and is associated with a more complicated and protracted hospital course. Its occurrence and duration are associated with characteristics of patients and their disease, not with a specific surgical technique.
[Results of Longo's stapled hemorrhoidectomy in ambulatory surgery for grade III-IV hemorrhoids].
Zaragozá, Cristóbal; García Fadrique, Alfonso; Castaño, Sergio; Villalba, Raúl; Bruna Esteban, Marcos; Redondo Cano, Carlos
2007-03-01
We prospectively evaluated the results of stapled hemorrhoidectomy for grade III-IV hemorrhoids in the ambulatory setting. Eighty-five consecutive patients with grade III-IV hemorrhoids, treated with the stapled technique with PPH01 in the Ambulatory Surgery Service of the General Hospital of Valencia were studied. Symptomatic, ASA I-II patients who agreed to undergo ambulatory surgery (vehicle, an accompanying adult, address with telephone, elevator, and basic hygiene conditions) were included. Thirty-nine percent were women and 61% were men, with a mean age of 47.6 years. A total of 85.9% had grade IV hemorrhoids and 14.1% had grade III. The average surgical time was 29.81+/- 12 minutes with a mean length of hospital stay of 168.88 +/- 88 minutes. Surgical complications consisted of 16 hemorrhages of the staple line (18.8%) and five hemorrhages due to mucous tear (5.9%). During the first 8 days the most frequent complication was pain (45.9%); only 7.1% of the patients required analgesia with opiates, and one patient required admission for 24 hours for analgesic purposes. Bleeding occurred in 10 patients, five of whom reported slight bleeding on defecation that stopped spontaneously; the remaining five required admission for 24 hours after surgical revision. Nine patients (10.6%) were admitted to the hospital for 24 hours, three due to intraoperative hemorrhage, five due to postoperative hemorrhage and one due to pain. A second intervention was required in 8.2%. Stapled hemorrhoidectomy can be applied in an ambulatory regime. Although technically simple with a short learning curve, this technique is not free of complications. Suitable patient selection and adequate perioperative information are indispensable for the ambulatory management of this disorder.
Multicenter prospective evaluation of a new articulating 5-mm endoscopic linear stapler.
Kuthe, Andreas; Haemmerle, Alexander; Ludwig, Kaja; Falck, Stephan; Hiller, Wolfgang; Mainik, Frederick; Freys, Stephan; Dubovoy, Lev; Jaehne, Joachim; Oldhafer, Karl
2016-05-01
The objective of this study was to evaluate the safety and efficacy of a novel 5-mm laparoscopic linear stapler in clinical gastrointestinal surgical applications. A prospective, single-arm study with an open enrollment of subjects requiring stapling of the gastrointestinal (GI) tract was performed. The study endpoints were the number of complications and technical failures associated with the use of a novel stapler when compared to similar events with conventional staplers as described in the medical literature. Seven centers enrolled 160 subjects, 150 of which were followed up to at least 30 days postoperatively. Intraoperative success: In 423 deployments, there were two staple line leaks and five staple line bleeds, all of which were intraoperatively resolved. In addition, incomplete staple lines were noted as a result of user error (n = 15) or device-related issues (n = 22), all of which were immediately resolved and none of which resulted in a complication or a change of the surgical procedure. Late outcomes: A total of 13 surgical complications in 160 patients were related to a GI transection or anastomosis, 12 of which related to a hand-sewn anastomosis or use of other commercially available staplers. One event (1/153, 0.065 %) on POD 1, involving bleeding of the staple line, was felt to be related to the use of the new stapler. The study confirmed that the new device was user-friendly (9 % incidence of problems firing the device), reliable (3 % device failures) and safe (<1 % complication rate related to the stapler). Based on these results, it would seem that this new 5-mm stapler is a safe and effective alternative to standard 12-mm staplers.
A revolutionary design change to improve stapler safety.
Arteaga-González, Iván J
2013-01-01
Postoperative staple line leaks and bleeding are the most common reasons for complications in surgical procedures that involve organ resection, such as sleeve gastrectomy. Increasing the safety of these operations requires improving the instruments (endostaplers or endocutters) used for stapling and sectioning the tissues. We present a new prototype stapler for marketing in resection surgery, especially designed for the sleeve gastrectomy. We suggest that the medical instrument industry creates devices in which the channel along which the knife blade runs is located asymmetrically. This would allow more staples to be placed on the side of the gastric remnant, thus improving the sealing and hemostasis of the suture line and reducing the number of complications for patients as a result. The application of new concepts in medical surgical devices can improve the safety of the procedures in our patients.
Transverse momentum-dependent parton distribution functions from lattice QCD
DOE Office of Scientific and Technical Information (OSTI.GOV)
Michael Engelhardt, Philipp Haegler, Bernhard Musch, John Negele, Andreas Schaefer
Transverse momentum-dependent parton distributions (TMDs) relevant for semi-inclusive deep inelastic scattering (SIDIS) and the Drell-Yan process can be defined in terms of matrix elements of a quark bilocal operator containing a staple-shaped Wilson connection. Starting from such a definition, a scheme to determine TMDs in lattice QCD is developed and explored. Parametrizing the aforementioned matrix elements in terms of invariant amplitudes permits a simple transformation of the problem to a Lorentz frame suited for the lattice calculation. Results for the Sivers and Boer-Mulders transverse momentum shifts are obtained using ensembles at the pion masses 369MeV and 518MeV, focusing in particularmore » on the dependence of these shifts on the staple extent and a Collins-Soper-type evolution parameter quantifying proximity of the staples to the light cone.« less
NASA Astrophysics Data System (ADS)
Pishravian, Arash; Aghabozorgi Sahaf, Masoud Reza
2012-12-01
In this paper speech-music separation using Blind Source Separation is discussed. The separating algorithm is based on the mutual information minimization where the natural gradient algorithm is used for minimization. In order to do that, score function estimation from observation signals (combination of speech and music) samples is needed. The accuracy and the speed of the mentioned estimation will affect on the quality of the separated signals and the processing time of the algorithm. The score function estimation in the presented algorithm is based on Gaussian mixture based kernel density estimation method. The experimental results of the presented algorithm on the speech-music separation and comparing to the separating algorithm which is based on the Minimum Mean Square Error estimator, indicate that it can cause better performance and less processing time
Tsanas, Athanasios; Zañartu, Matías; Little, Max A.; Fox, Cynthia; Ramig, Lorraine O.; Clifford, Gari D.
2014-01-01
There has been consistent interest among speech signal processing researchers in the accurate estimation of the fundamental frequency (F0) of speech signals. This study examines ten F0 estimation algorithms (some well-established and some proposed more recently) to determine which of these algorithms is, on average, better able to estimate F0 in the sustained vowel /a/. Moreover, a robust method for adaptively weighting the estimates of individual F0 estimation algorithms based on quality and performance measures is proposed, using an adaptive Kalman filter (KF) framework. The accuracy of the algorithms is validated using (a) a database of 117 synthetic realistic phonations obtained using a sophisticated physiological model of speech production and (b) a database of 65 recordings of human phonations where the glottal cycles are calculated from electroglottograph signals. On average, the sawtooth waveform inspired pitch estimator and the nearly defect-free algorithms provided the best individual F0 estimates, and the proposed KF approach resulted in a ∼16% improvement in accuracy over the best single F0 estimation algorithm. These findings may be useful in speech signal processing applications where sustained vowels are used to assess vocal quality, when very accurate F0 estimation is required. PMID:24815269
Gui, Guan; Chen, Zhang-xin; Xu, Li; Wan, Qun; Huang, Jiyan; Adachi, Fumiyuki
2014-01-01
Channel estimation problem is one of the key technical issues in sparse frequency-selective fading multiple-input multiple-output (MIMO) communication systems using orthogonal frequency division multiplexing (OFDM) scheme. To estimate sparse MIMO channels, sparse invariable step-size normalized least mean square (ISS-NLMS) algorithms were applied to adaptive sparse channel estimation (ACSE). It is well known that step-size is a critical parameter which controls three aspects: algorithm stability, estimation performance, and computational cost. However, traditional methods are vulnerable to cause estimation performance loss because ISS cannot balance the three aspects simultaneously. In this paper, we propose two stable sparse variable step-size NLMS (VSS-NLMS) algorithms to improve the accuracy of MIMO channel estimators. First, ASCE is formulated in MIMO-OFDM systems. Second, different sparse penalties are introduced to VSS-NLMS algorithm for ASCE. In addition, difference between sparse ISS-NLMS algorithms and sparse VSS-NLMS ones is explained and their lower bounds are also derived. At last, to verify the effectiveness of the proposed algorithms for ASCE, several selected simulation results are shown to prove that the proposed sparse VSS-NLMS algorithms can achieve better estimation performance than the conventional methods via mean square error (MSE) and bit error rate (BER) metrics.
Gui, Guan; Chen, Zhang-xin; Xu, Li; Wan, Qun; Huang, Jiyan; Adachi, Fumiyuki
2014-01-01
Channel estimation problem is one of the key technical issues in sparse frequency-selective fading multiple-input multiple-output (MIMO) communication systems using orthogonal frequency division multiplexing (OFDM) scheme. To estimate sparse MIMO channels, sparse invariable step-size normalized least mean square (ISS-NLMS) algorithms were applied to adaptive sparse channel estimation (ACSE). It is well known that step-size is a critical parameter which controls three aspects: algorithm stability, estimation performance, and computational cost. However, traditional methods are vulnerable to cause estimation performance loss because ISS cannot balance the three aspects simultaneously. In this paper, we propose two stable sparse variable step-size NLMS (VSS-NLMS) algorithms to improve the accuracy of MIMO channel estimators. First, ASCE is formulated in MIMO-OFDM systems. Second, different sparse penalties are introduced to VSS-NLMS algorithm for ASCE. In addition, difference between sparse ISS-NLMS algorithms and sparse VSS-NLMS ones is explained and their lower bounds are also derived. At last, to verify the effectiveness of the proposed algorithms for ASCE, several selected simulation results are shown to prove that the proposed sparse VSS-NLMS algorithms can achieve better estimation performance than the conventional methods via mean square error (MSE) and bit error rate (BER) metrics. PMID:25089286
Stapled peptides as a new technology to investigate protein-protein interactions in human platelets.
Iegre, Jessica; Ahmed, Niaz S; Gaynord, Josephine S; Wu, Yuteng; Herlihy, Kara M; Tan, Yaw Sing; Lopes-Pires, Maria E; Jha, Rupam; Lau, Yu Heng; Sore, Hannah F; Verma, Chandra; O' Donovan, Daniel H; Pugh, Nicholas; Spring, David R
2018-05-28
Platelets are blood cells with numerous crucial pathophysiological roles in hemostasis, cardiovascular thrombotic events and cancer metastasis. Platelet activation requires the engagement of intracellular signalling pathways that involve protein-protein interactions (PPIs). A better understanding of these pathways is therefore crucial for the development of selective anti-platelet drugs. New strategies for studying PPIs in human platelets are required to overcome limitations associated with conventional platelet research methods. For example, small molecule inhibitors can lack selectivity and are often difficult to design and synthesise. Additionally, development of transgenic animal models is costly and time-consuming and conventional recombinant techniques are ineffective due to the lack of a nucleus in platelets. Herein, we describe the generation of a library of novel, functionalised stapled peptides and their first application in the investigation of platelet PPIs. Moreover, the use of platelet-permeable stapled Bim BH3 peptides confirms the part of Bim in phosphatidyl-serine (PS) exposure and reveals a role for the Bim protein in platelet activatory processes. Our work demonstrates that functionalised stapled peptides are a complementary alternative to conventional platelet research methods, and could make a significant contribution to the understanding of platelet signalling pathways and hence to the development of anti-platelet drugs.
Berjano, Pedro; Blanco, Juan Francisco; Rendon, Diego; Villafañe, Jorge Hugo; Pescador, David; Atienza, Carlos Manuel
2015-11-01
To assess, with finite element analysis and an in vitro biomechanical study in cadaver, whether the implementation of an anterior interbody cage made of hedrocel with nitinol shape memory staples in compression increases the stiffness of the stand-alone interbody cage and to compare these constructs' stiffness to other constructs common in clinical practice. A biomechanical study with a finite element analysis and cadaveric testing assessed the stiffness of different fixation modes for the L4-L5 functional spinal unit: intact spine, destabilized spine with discectomy, posterior pedicle-screw fixation, anterior stand-alone interbody cage, anterior interbody cage with bilateral pedicle screws and anterior interbody cage with two shape memory staples in compression. These modalities of vertebral fixation were compared in four loading modes (flexion, extension, lateral bending, and axial rotation). The L4-L5 spinal unit with an anterior interbody cage and two staples was stiffer than the stand-alone cage. The construct stiffness was similar to that of a model of posterior pedicular stabilization. The stiffness was lower than that of the anterior cage plus bilateral pedicle-screw fixation. The use of an anterior interbody implant with shape memory staples in compression may be an alternative to isolated posterior fixation and to anterior isolated implants, with increased stiffness.
Chang, Yong S.; Graves, Bradford; Guerlavais, Vincent; Tovar, Christian; Packman, Kathryn; To, Kwong-Him; Olson, Karen A.; Kesavan, Kamala; Gangurde, Pranoti; Mukherjee, Aditi; Baker, Theresa; Darlak, Krzysztof; Elkin, Carl; Filipovic, Zoran; Qureshi, Farooq Z.; Cai, Hongliang; Berry, Pamela; Feyfant, Eric; Shi, Xiangguo E.; Horstick, James; Annis, D. Allen; Manning, Anthony M.; Fotouhi, Nader; Nash, Huw; Vassilev, Lyubomir T.; Sawyer, Tomi K.
2013-01-01
Stapled α−helical peptides have emerged as a promising new modality for a wide range of therapeutic targets. Here, we report a potent and selective dual inhibitor of MDM2 and MDMX, ATSP-7041, which effectively activates the p53 pathway in tumors in vitro and in vivo. Specifically, ATSP-7041 binds both MDM2 and MDMX with nanomolar affinities, shows submicromolar cellular activities in cancer cell lines in the presence of serum, and demonstrates highly specific, on-target mechanism of action. A high resolution (1.7-Å) X-ray crystal structure reveals its molecular interactions with the target protein MDMX, including multiple contacts with key amino acids as well as a role for the hydrocarbon staple itself in target engagement. Most importantly, ATSP-7041 demonstrates robust p53-dependent tumor growth suppression in MDM2/MDMX-overexpressing xenograft cancer models, with a high correlation to on-target pharmacodynamic activity, and possesses favorable pharmacokinetic and tissue distribution properties. Overall, ATSP-7041 demonstrates in vitro and in vivo proof-of-concept that stapled peptides can be developed as therapeutically relevant inhibitors of protein–protein interaction and may offer a viable modality for cancer therapy. PMID:23946421
Amisaki, Masataka; Kihara, Kyoichi; Endo, Kanenori; Suzuki, Kazunori; Nakamura, Seiichi; Sawata, Takashi; Shimizu, Tetsu
2016-07-01
Laparoscopic total gastrectomy is not widely performed because of the difficulty of esophagojejunal reconstruction. This study analyzed complication rates of two different methods for reconstruction by a circular stapler after totally laparoscopic total gastrectomy (TLTG). Between 2010 and 2014, clinical data of 19 patients who underwent TLTG for gastric adenocarcinoma were collected retrospectively. There were two methods to fix the anvil of a circular stapler into the distal esophagus: In the single-stapling technique (SST) group, Endo-PSI(II) was used for purse-suturing on the distal esophagus for reconstruction, and in the hemi-double-stapling technique (hemi-DST) group, the esophagus was cut by linear stapler with the entry hole of the anvil shaft opened after inserting the anvil tail. In both groups, surgical procedures were the same, except for the reconstruction. All TLTGs were performed securely without mortality. Intracorporeal laparoscopic esophagojejunal anastomosis was performed successfully for all the patients. In the hemi-DST group, four patients experienced anastomotic stenosis, three of whom required endoscopic balloon dilation. In contrast, no stenosis was seen in the SST group (p = 0.033). Anastomosis with SST is preferred to that with hemi-DST to minimize postoperative complications.
Investigation of the best suture pattern to close a stuffed Christmas turkey.
Verwilghen, D; Busoni, V; van Galen, G; Wilke, M
Instructions on how to debone and stuff a turkey are available, but what is the best way to close it up? A randomised trial involving 15 turkeys was performed in order to evaluate skin disruption scores and cosmetic outcomes following the use of different suture patterns. Turkeys were deboned, stuffed and cooked according to guidelines of the US Department of Agriculture Food Safety and Inspection Services. After stuffing, they were randomly assigned to one of five closure groups: simple continuous Lembert; simple continuous Cushing; simple continuous Utrecht; simple continuous; or staples. Turkeys were cooked at 180 °C for two hours ensuring core temperature reached 75 °C. Suture line integrity was evaluated after removal of the sutures and the cosmetic aspect was graded. Before cooking, the Utrecht pattern and skin staples offered the best cosmetic result. After removal of the sutures, the skin remained intact only in the stapled group. All other suture patterns disrupted the skin after removal of the sutures, rendering the turkey less cosmetically appealing for serving. Closure of a stuffed turkey was best performed using skin staples to achieve the best cosmetic results. Using this technique you will be able to impress family and friends at a Christmas dinner, and finally show them your surgical skills.
Fertilizing growth: Agricultural inputs and their effects in economic development.
McArthur, John W; McCord, Gordon C
2017-07-01
This paper estimates the role of agronomic inputs in cereal yield improvements and the consequences for countries' processes of structural change. The results suggest a clear role for fertilizer, modern seeds and water in boosting yields. We then test for respective empirical links between agricultural yields and economic growth, labor share in agriculture and non-agricultural value added per worker. The identification strategy includes a novel instrumental variable that exploits the unique economic geography of fertilizer production and transport costs to countries' agricultural heartlands. We estimate that a half ton increase in staple yields generates a 14 to 19 percent higher GDP per capita and a 4.6 to 5.6 percentage point lower labor share in agriculture five years later. The results suggest a strong role for agricultural productivity as a driver of structural change.
Method for hyperspectral imagery exploitation and pixel spectral unmixing
NASA Technical Reports Server (NTRS)
Lin, Ching-Fang (Inventor)
2003-01-01
An efficiently hybrid approach to exploit hyperspectral imagery and unmix spectral pixels. This hybrid approach uses a genetic algorithm to solve the abundance vector for the first pixel of a hyperspectral image cube. This abundance vector is used as initial state in a robust filter to derive the abundance estimate for the next pixel. By using Kalman filter, the abundance estimate for a pixel can be obtained in one iteration procedure which is much fast than genetic algorithm. The output of the robust filter is fed to genetic algorithm again to derive accurate abundance estimate for the current pixel. The using of robust filter solution as starting point of the genetic algorithm speeds up the evolution of the genetic algorithm. After obtaining the accurate abundance estimate, the procedure goes to next pixel, and uses the output of genetic algorithm as the previous state estimate to derive abundance estimate for this pixel using robust filter. And again use the genetic algorithm to derive accurate abundance estimate efficiently based on the robust filter solution. This iteration continues until pixels in a hyperspectral image cube end.
Algorithms for Brownian first-passage-time estimation
NASA Astrophysics Data System (ADS)
Adib, Artur B.
2009-09-01
A class of algorithms in discrete space and continuous time for Brownian first-passage-time estimation is considered. A simple algorithm is derived that yields exact mean first-passage times (MFPTs) for linear potentials in one dimension, regardless of the lattice spacing. When applied to nonlinear potentials and/or higher spatial dimensions, numerical evidence suggests that this algorithm yields MFPT estimates that either outperform or rival Langevin-based (discrete time and continuous space) estimates.
A fast and accurate frequency estimation algorithm for sinusoidal signal with harmonic components
NASA Astrophysics Data System (ADS)
Hu, Jinghua; Pan, Mengchun; Zeng, Zhidun; Hu, Jiafei; Chen, Dixiang; Tian, Wugang; Zhao, Jianqiang; Du, Qingfa
2016-10-01
Frequency estimation is a fundamental problem in many applications, such as traditional vibration measurement, power system supervision, and microelectromechanical system sensors control. In this paper, a fast and accurate frequency estimation algorithm is proposed to deal with low efficiency problem in traditional methods. The proposed algorithm consists of coarse and fine frequency estimation steps, and we demonstrate that it is more efficient than conventional searching methods to achieve coarse frequency estimation (location peak of FFT amplitude) by applying modified zero-crossing technique. Thus, the proposed estimation algorithm requires less hardware and software sources and can achieve even higher efficiency when the experimental data increase. Experimental results with modulated magnetic signal show that the root mean square error of frequency estimation is below 0.032 Hz with the proposed algorithm, which has lower computational complexity and better global performance than conventional frequency estimation methods.
An Efficient Distributed Compressed Sensing Algorithm for Decentralized Sensor Network.
Liu, Jing; Huang, Kaiyu; Zhang, Guoxian
2017-04-20
We consider the joint sparsity Model 1 (JSM-1) in a decentralized scenario, where a number of sensors are connected through a network and there is no fusion center. A novel algorithm, named distributed compact sensing matrix pursuit (DCSMP), is proposed to exploit the computational and communication capabilities of the sensor nodes. In contrast to the conventional distributed compressed sensing algorithms adopting a random sensing matrix, the proposed algorithm focuses on the deterministic sensing matrices built directly on the real acquisition systems. The proposed DCSMP algorithm can be divided into two independent parts, the common and innovation support set estimation processes. The goal of the common support set estimation process is to obtain an estimated common support set by fusing the candidate support set information from an individual node and its neighboring nodes. In the following innovation support set estimation process, the measurement vector is projected into a subspace that is perpendicular to the subspace spanned by the columns indexed by the estimated common support set, to remove the impact of the estimated common support set. We can then search the innovation support set using an orthogonal matching pursuit (OMP) algorithm based on the projected measurement vector and projected sensing matrix. In the proposed DCSMP algorithm, the process of estimating the common component/support set is decoupled with that of estimating the innovation component/support set. Thus, the inaccurately estimated common support set will have no impact on estimating the innovation support set. It is proven that under the condition the estimated common support set contains the true common support set, the proposed algorithm can find the true innovation set correctly. Moreover, since the innovation support set estimation process is independent of the common support set estimation process, there is no requirement for the cardinality of both sets; thus, the proposed DCSMP algorithm is capable of tackling the unknown sparsity problem successfully.
ERIC Educational Resources Information Center
Martin-Fernandez, Manuel; Revuelta, Javier
2017-01-01
This study compares the performance of two estimation algorithms of new usage, the Metropolis-Hastings Robins-Monro (MHRM) and the Hamiltonian MCMC (HMC), with two consolidated algorithms in the psychometric literature, the marginal likelihood via EM algorithm (MML-EM) and the Markov chain Monte Carlo (MCMC), in the estimation of multidimensional…
A global food demand model for the assessment of complex human-earth systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
EDMONDS, JAMES A.; LINK, ROBERT; WALDHOFF, STEPHANIE T.
Demand for agricultural products is an important problem in climate change economics. Food consumption will shape and shaped by climate change and emissions mitigation policies through interactions with bioenergy and afforestation, two critical issues in meeting international climate goals such as two-degrees. We develop a model of food demand for staple and nonstaple commodities that evolves with changing incomes and prices. The model addresses a long-standing issue in estimating food demands, the evolution of demand relationships across large changes in income and prices. We discuss the model, some of its properties and limitations. We estimate parameter values using pooled cross-sectional-time-seriesmore » observations and the Metropolis Monte Carlo method and cross-validate the model by estimating parameters using a subset of the observations and test its ability to project into the unused observations. Finally, we apply bias correction techniques borrowed from the climate-modeling community and report results.« less
Coupled Inertial Navigation and Flush Air Data Sensing Algorithm for Atmosphere Estimation
NASA Technical Reports Server (NTRS)
Karlgaard, Christopher D.; Kutty, Prasad; Schoenenberger, Mark
2015-01-01
This paper describes an algorithm for atmospheric state estimation that is based on a coupling between inertial navigation and flush air data sensing pressure measurements. In this approach, the full navigation state is used in the atmospheric estimation algorithm along with the pressure measurements and a model of the surface pressure distribution to directly estimate atmospheric winds and density using a nonlinear weighted least-squares algorithm. The approach uses a high fidelity model of atmosphere stored in table-look-up form, along with simplified models of that are propagated along the trajectory within the algorithm to provide prior estimates and covariances to aid the air data state solution. Thus, the method is essentially a reduced-order Kalman filter in which the inertial states are taken from the navigation solution and atmospheric states are estimated in the filter. The algorithm is applied to data from the Mars Science Laboratory entry, descent, and landing from August 2012. Reasonable estimates of the atmosphere and winds are produced by the algorithm. The observability of winds along the trajectory are examined using an index based on the discrete-time observability Gramian and the pressure measurement sensitivity matrix. The results indicate that bank reversals are responsible for adding information content to the system. The algorithm is then applied to the design of the pressure measurement system for the Mars 2020 mission. The pressure port layout is optimized to maximize the observability of atmospheric states along the trajectory. Linear covariance analysis is performed to assess estimator performance for a given pressure measurement uncertainty. The results indicate that the new tightly-coupled estimator can produce enhanced estimates of atmospheric states when compared with existing algorithms.
Direction of Arrival Estimation Using a Reconfigurable Array
2005-05-06
civilian world. Keywords: Direction-of-arrival Estimation MUSIC algorithm Reconfigurable Array Experimental Created by Neevia Personal...14. SUBJECT TERMS: Direction-of-arrival ; Estimation ; MUSIC algorithm ; Reconfigurable ; Array ; Experimental 16. PRICE CODE 17...9 1.5 MuSiC Algorithm
Subcutaneous hemangiosarcoma induced by a foreign body (steel staple) in a cat.
Tan, Rommel Max; Singh, Kuldeep; Sandman, Kristi
2013-04-01
An 8-year-old, female domestic shorthair cat was presented with a ventral abdominal subcutaneous mass. A radiograph showed that the center of the mass contained what appeared to be steel sutures, presumed to be from an ovariohysterectomy performed 7 years earlier. The excised mass was irregular and contained numerous pockets filled with friable necrotic material and hemorrhages that were dissected by fibrous connective tissue bands. Multiple tangled and fragmented pieces of steel staples were deeply embedded within the mass. Histologically, the mass was non-encapsulated, densely cellular, and infiltrative. Neoplastic cells lined caverns and channels and were factor VIII-positive by immunohistochemistry. The neoplastic cells were oval to round with granular cytoplasm and vesicular nucleus and exhibited moderate cellular and nuclear pleomorphism. A diagnosis of subcutaneous hemangiosarcoma was made. To our knowledge, this is the first report of foreign body associated hemangiosarcoma and the first case of steel staple associated neoplasm in domestic animals.
Hydrocarbon-Stapled Peptides: Principles, Practice, and Progress
2015-01-01
Protein structure underlies essential biological processes and provides a blueprint for molecular mimicry that drives drug discovery. Although small molecules represent the lion’s share of agents that target proteins for therapeutic benefit, there remains no substitute for the natural properties of proteins and their peptide subunits in the majority of biological contexts. The peptide α-helix represents a common structural motif that mediates communication between signaling proteins. Because peptides can lose their shape when taken out of context, developing chemical interventions to stabilize their bioactive structure remains an active area of research. The all-hydrocarbon staple has emerged as one such solution, conferring α-helical structure, protease resistance, cellular penetrance, and biological activity upon successful incorporation of a series of design and application principles. Here, we describe our more than decade-long experience in developing stapled peptides as biomedical research tools and prototype therapeutics, highlighting lessons learned, pitfalls to avoid, and keys to success. PMID:24601557
Watanabe, Yui; Aoki, Masaya; Suzuki, Soichi; Umehara, Tadashi; Harada, Aya; Wakida, Kazuhiro; Nagata, Toshiyuki; Kariatsumari, Kota; Nakamura, Yoshihiro; Sato, Masami
2015-11-01
A 68-year-old male with a tracheostoma due to hypopharyngeal cancer was admitted because his chest computed tomography (CT) showed a small nodule in the right middle lobe. Following a partial resection of the right middle lobe, histopathological diagnosis of the resected sample was that of organizing pneumonia. Eleven months later, chest CT showed a mass with pleural indentation and spiculation in the right middle lobe. 18-Fluorodeoxyglucose-positron emission tomography showed significant accumulation in the middle lobe tumor mass shadow. The abnormal chest shadow that had developed around surgical staples suggested inadequate resection and tumor recurrence. As the abnormal radiological shadow was enlarging, middle lobectomy was carried out. Histological examination revealed that the tumor was a lung abscess without malignant features. This is a unique case of lung abscess mimicking lung cancer which developed around staples used during partial resection of the lung.
NASA Astrophysics Data System (ADS)
Yao, Yunjun; Liang, Shunlin; Yu, Jian; Zhao, Shaohua; Lin, Yi; Jia, Kun; Zhang, Xiaotong; Cheng, Jie; Xie, Xianhong; Sun, Liang; Wang, Xuanyu; Zhang, Lilin
2017-04-01
Accurate estimates of terrestrial latent heat of evaporation (LE) for different biomes are essential to assess energy, water and carbon cycles. Different satellite- based Priestley-Taylor (PT) algorithms have been developed to estimate LE in different biomes. However, there are still large uncertainties in LE estimates for different PT algorithms. In this study, we evaluated differences in estimating terrestrial water flux in different biomes from three satellite-based PT algorithms using ground-observed data from eight eddy covariance (EC) flux towers of China. The results reveal that large differences in daily LE estimates exist based on EC measurements using three PT algorithms among eight ecosystem types. At the forest (CBS) site, all algorithms demonstrate high performance with low root mean square error (RMSE) (less than 16 W/m2) and high squared correlation coefficient (R2) (more than 0.9). At the village (HHV) site, the ATI-PT algorithm has the lowest RMSE (13.9 W/m2), with bias of 2.7 W/m2 and R2 of 0.66. At the irrigated crop (HHM) site, almost all models algorithms underestimate LE, indicating these algorithms may not capture wet soil evaporation by parameterization of the soil moisture. In contrast, the SM-PT algorithm shows high values of R2 (comparable to those of ATI-PT and VPD-PT) at most other (grass, wetland, desert and Gobi) biomes. There are no obvious differences in seasonal LE estimation using MODIS NDVI and LAI at most sites. However, all meteorological or satellite-based water-related parameters used in the PT algorithm have uncertainties for optimizing water constraints. This analysis highlights the need to improve PT algorithms with regard to water constraints.
Analysis of estimation algorithms for CDTI and CAS applications
NASA Technical Reports Server (NTRS)
Goka, T.
1985-01-01
Estimation algorithms for Cockpit Display of Traffic Information (CDTI) and Collision Avoidance System (CAS) applications were analyzed and/or developed. The algorithms are based on actual or projected operational and performance characteristics of an Enhanced TCAS II traffic sensor developed by Bendix and the Federal Aviation Administration. Three algorithm areas are examined and discussed. These are horizontal x and y, range and altitude estimation algorithms. Raw estimation errors are quantified using Monte Carlo simulations developed for each application; the raw errors are then used to infer impacts on the CDTI and CAS applications. Applications of smoothing algorithms to CDTI problems are also discussed briefly. Technical conclusions are summarized based on the analysis of simulation results.
Wynant, Willy; Abrahamowicz, Michal
2016-11-01
Standard optimization algorithms for maximizing likelihood may not be applicable to the estimation of those flexible multivariable models that are nonlinear in their parameters. For applications where the model's structure permits separating estimation of mutually exclusive subsets of parameters into distinct steps, we propose the alternating conditional estimation (ACE) algorithm. We validate the algorithm, in simulations, for estimation of two flexible extensions of Cox's proportional hazards model where the standard maximum partial likelihood estimation does not apply, with simultaneous modeling of (1) nonlinear and time-dependent effects of continuous covariates on the hazard, and (2) nonlinear interaction and main effects of the same variable. We also apply the algorithm in real-life analyses to estimate nonlinear and time-dependent effects of prognostic factors for mortality in colon cancer. Analyses of both simulated and real-life data illustrate good statistical properties of the ACE algorithm and its ability to yield new potentially useful insights about the data structure. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Technical Reports Server (NTRS)
Phinney, D. E. (Principal Investigator)
1980-01-01
An algorithm for estimating spectral crop calendar shifts of spring small grains was applied to 1978 spring wheat fields. The algorithm provides estimates of the date of peak spectral response by maximizing the cross correlation between a reference profile and the observed multitemporal pattern of Kauth-Thomas greenness for a field. A methodology was developed for estimation of crop development stage from the date of peak spectral response. Evaluation studies showed that the algorithm provided stable estimates with no geographical bias. Crop development stage estimates had a root mean square error near 10 days. The algorithm was recommended for comparative testing against other models which are candidates for use in AgRISTARS experiments.
Pediatric Brain Extraction Using Learning-based Meta-algorithm
Shi, Feng; Wang, Li; Dai, Yakang; Gilmore, John H.; Lin, Weili; Shen, Dinggang
2012-01-01
Magnetic resonance imaging of pediatric brain provides valuable information for early brain development studies. Automated brain extraction is challenging due to the small brain size and dynamic change of tissue contrast in the developing brains. In this paper, we propose a novel Learning Algorithm for Brain Extraction and Labeling (LABEL) specially for the pediatric MR brain images. The idea is to perform multiple complementary brain extractions on a given testing image by using a meta-algorithm, including BET and BSE, where the parameters of each run of the meta-algorithm are effectively learned from the training data. Also, the representative subjects are selected as exemplars and used to guide brain extraction of new subjects in different age groups. We further develop a level-set based fusion method to combine multiple brain extractions together with a closed smooth surface for obtaining the final extraction. The proposed method has been extensively evaluated in subjects of three representative age groups, such as neonate (less than 2 months), infant (1–2 years), and child (5–18 years). Experimental results show that, with 45 subjects for training (15 neonates, 15 infant, and 15 children), the proposed method can produce more accurate brain extraction results on 246 testing subjects (75 neonates, 126 infants, and 45 children), i.e., at average Jaccard Index of 0.953, compared to those by BET (0.918), BSE (0.902), ROBEX (0.901), GCUT (0.856), and other fusion methods such as Majority Voting (0.919) and STAPLE (0.941). Along with the largely-improved computational efficiency, the proposed method demonstrates its ability of automated brain extraction for pediatric MR images in a large age range. PMID:22634859
Multiatlas segmentation of thoracic and abdominal anatomy with level set-based local search.
Schreibmann, Eduard; Marcus, David M; Fox, Tim
2014-07-08
Segmentation of organs at risk (OARs) remains one of the most time-consuming tasks in radiotherapy treatment planning. Atlas-based segmentation methods using single templates have emerged as a practical approach to automate the process for brain or head and neck anatomy, but pose significant challenges in regions where large interpatient variations are present. We show that significant changes are needed to autosegment thoracic and abdominal datasets by combining multi-atlas deformable registration with a level set-based local search. Segmentation is hierarchical, with a first stage detecting bulk organ location, and a second step adapting the segmentation to fine details present in the patient scan. The first stage is based on warping multiple presegmented templates to the new patient anatomy using a multimodality deformable registration algorithm able to cope with changes in scanning conditions and artifacts. These segmentations are compacted in a probabilistic map of organ shape using the STAPLE algorithm. Final segmentation is obtained by adjusting the probability map for each organ type, using customized combinations of delineation filters exploiting prior knowledge of organ characteristics. Validation is performed by comparing automated and manual segmentation using the Dice coefficient, measured at an average of 0.971 for the aorta, 0.869 for the trachea, 0.958 for the lungs, 0.788 for the heart, 0.912 for the liver, 0.884 for the kidneys, 0.888 for the vertebrae, 0.863 for the spleen, and 0.740 for the spinal cord. Accurate atlas segmentation for abdominal and thoracic regions can be achieved with the usage of a multi-atlas and perstructure refinement strategy. To improve clinical workflow and efficiency, the algorithm was embedded in a software service, applying the algorithm automatically on acquired scans without any user interaction.
Performance in population models for count data, part II: a new SAEM algorithm
Savic, Radojka; Lavielle, Marc
2009-01-01
Analysis of count data from clinical trials using mixed effect analysis has recently become widely used. However, algorithms available for the parameter estimation, including LAPLACE and Gaussian quadrature (GQ), are associated with certain limitations, including bias in parameter estimates and the long analysis runtime. The stochastic approximation expectation maximization (SAEM) algorithm has proven to be a very efficient and powerful tool in the analysis of continuous data. The aim of this study was to implement and investigate the performance of a new SAEM algorithm for application to count data. A new SAEM algorithm was implemented in MATLAB for estimation of both, parameters and the Fisher information matrix. Stochastic Monte Carlo simulations followed by re-estimation were performed according to scenarios used in previous studies (part I) to investigate properties of alternative algorithms (1). A single scenario was used to explore six probability distribution models. For parameter estimation, the relative bias was less than 0.92% and 4.13 % for fixed and random effects, for all models studied including ones accounting for over- or under-dispersion. Empirical and estimated relative standard errors were similar, with distance between them being <1.7 % for all explored scenarios. The longest CPU time was 95s for parameter estimation and 56s for SE estimation. The SAEM algorithm was extended for analysis of count data. It provides accurate estimates of both, parameters and standard errors. The estimation is significantly faster compared to LAPLACE and GQ. The algorithm is implemented in Monolix 3.1, (beta-version available in July 2009). PMID:19680795
Performance analysis of structured gradient algorithm. [for adaptive beamforming linear arrays
NASA Technical Reports Server (NTRS)
Godara, Lal C.
1990-01-01
The structured gradient algorithm uses a structured estimate of the array correlation matrix (ACM) to estimate the gradient required for the constrained least-mean-square (LMS) algorithm. This structure reflects the structure of the exact array correlation matrix for an equispaced linear array and is obtained by spatial averaging of the elements of the noisy correlation matrix. In its standard form the LMS algorithm does not exploit the structure of the array correlation matrix. The gradient is estimated by multiplying the array output with the receiver outputs. An analysis of the two algorithms is presented to show that the covariance of the gradient estimated by the structured method is less sensitive to the look direction signal than that estimated by the standard method. The effect of the number of elements on the signal sensitivity of the two algorithms is studied.
Polyester projects for India, Pakistan
DOE Office of Scientific and Technical Information (OSTI.GOV)
Siddiqi, R.
1993-02-10
India's Indo Rama Synthetics (Bombay) is planning a $186-million integrated polyester fiber and filament complex at Nagpur, Maharashtra. The complex will have annual capacities for 38,000 m.t. of polyester chips by polycondensation, 25,000 m.t. of polyester staple fiber, and 12,000 m.t. of polyester blended yarn. The company is negotiating with the main world suppliers of polycondensation technology. The first stage of the project is slated to begin production by the end of this year and be fully completed by 1994. In Pakistan, National Fibers Ltd. (PNF; Karachi) has signed a deal with Zimmer (Frankfurt) for technology, procurement, construction, and supportmore » work to expand polyester staple fiber capacity from 14,000 m.t./year to 52,000 m.t./year. The technology involves a continuous polymerization process. The project also calls for improvements to PNF's existing batch plant. It is scheduled for completion by the end of 1994. Total cost of the project is estimated at Rs1.745 billion ($70 million), out of which the foreign exchange component is Rs1.05 billion. The Islamic Development Bank (Jeddah; Saudi Arabia) has already approved a $27-million slice of the financing, while the balance of the foreign exchange loan is being arranged through suppliers credit. Local currency loans will be provided by other financial institutions in Pakistan.« less
Grassi, Roberto; Romano, Stefania; Micera, Osvaldo; Fioroni, Claudio; Boller, Brigitta
2005-03-01
Longo's procedure of double stapled trans anal rectal resection (STARR) has been evocated as surgical treatment of the obstructed defecation syndrome (ODS) in patients with rectal mucosal prolapse. The aim of this study was to investigate the post-interventional findings of this technique, to help radiologist in knowledge of the changed morphology of the rectal lumen, also in attempt to recognize some potential related complications.
Findeisen, Felix; Campiglio, Marta; Jo, Hyunil; Abderemane-Ali, Fayal; Rumpf, Christine H; Pope, Lianne; Rossen, Nathan D; Flucher, Bernhard E; DeGrado, William F; Minor, Daniel L
2017-06-21
For many voltage-gated ion channels (VGICs), creation of a properly functioning ion channel requires the formation of specific protein-protein interactions between the transmembrane pore-forming subunits and cystoplasmic accessory subunits. Despite the importance of such protein-protein interactions in VGIC function and assembly, their potential as sites for VGIC modulator development has been largely overlooked. Here, we develop meta-xylyl (m-xylyl) stapled peptides that target a prototypic VGIC high affinity protein-protein interaction, the interaction between the voltage-gated calcium channel (Ca V ) pore-forming subunit α-interaction domain (AID) and cytoplasmic β-subunit (Ca V β). We show using circular dichroism spectroscopy, X-ray crystallography, and isothermal titration calorimetry that the m-xylyl staples enhance AID helix formation are structurally compatible with native-like AID:Ca V β interactions and reduce the entropic penalty associated with AID binding to Ca V β. Importantly, electrophysiological studies reveal that stapled AID peptides act as effective inhibitors of the Ca V α 1 :Ca V β interaction that modulate Ca V function in an Ca V β isoform-selective manner. Together, our studies provide a proof-of-concept demonstration of the use of protein-protein interaction inhibitors to control VGIC function and point to strategies for improved AID-based Ca V modulator design.
Expected increase in staple crop imports in water-scarce countries in 2050
NASA Astrophysics Data System (ADS)
Chouchane, Hatem; Krol, Maarten; Hoekstra, Arjen
2017-04-01
Water scarcity is a major challenge in the coming decades. The increasing population and the changing pattern of water availability that results from global warming reduce the potential of sufficient food production in many countries over the world. Today, two thirds of the global population are already living under conditions of severe water scarcity at least one month of the year. This rises the importance of addressing the present and future relationship between water availability and food import in water-scarce countries. The net import of staple crops (barley, cassava, maize, millet and products, oats, potatoes, rice, rye, sorghum, soybeans, sweet potatoes, wheat and yams) is analysed in relation to water availability per capita for the period 1961-2010, considering five decadal averages. The relation found is used together with the low, medium and high population growth scenarios from the United Nations to project the staple crops import in water-scarce countries for the year 2050. Additionally, we investigate the uncertainties related to the three population scenarios. Results will help countries to better understand the impact of population growth and limited water resources on their future food trade. This study will provide a valuable supporting tool for policy makers towards more sustainable and water-efficient food production as targeted with the Sustainable Development Goals. Keywords: Water Availability, Food Import, Staple Crops, Water Scarcity, Water-Use Efficiency, Sustainable Development Goals.
Checco, James W; Lee, Erinna F; Evangelista, Marco; Sleebs, Nerida J; Rogers, Kelly; Pettikiriarachchi, Anne; Kershaw, Nadia J; Eddinger, Geoffrey A; Belair, David G; Wilson, Julia L; Eller, Chelcie H; Raines, Ronald T; Murphy, William L; Smith, Brian J; Gellman, Samuel H; Fairlie, W Douglas
2015-09-09
Peptides can be developed as effective antagonists of protein-protein interactions, but conventional peptides (i.e., oligomers of l-α-amino acids) suffer from significant limitations in vivo. Short half-lives due to rapid proteolytic degradation and an inability to cross cell membranes often preclude biological applications of peptides. Oligomers that contain both α- and β-amino acid residues ("α/β-peptides") manifest decreased susceptibility to proteolytic degradation, and when properly designed these unnatural oligomers can mimic the protein-recognition properties of analogous "α-peptides". This report documents an extension of the α/β-peptide approach to target intracellular protein-protein interactions. Specifically, we have generated α/β-peptides based on a "stapled" Bim BH3 α-peptide, which contains a hydrocarbon cross-link to enhance α-helix stability. We show that a stapled α/β-peptide can structurally and functionally mimic the parent stapled α-peptide in its ability to enter certain types of cells and block protein-protein interactions associated with apoptotic signaling. However, the α/β-peptide is nearly 100-fold more resistant to proteolysis than is the parent stapled α-peptide. These results show that backbone modification, a strategy that has received relatively little attention in terms of peptide engineering for biomedical applications, can be combined with more commonly deployed peripheral modifications such as side chain cross-linking to produce synergistic benefits.
Yuan, Ya-Qun; Li, Fan; Meng, Pai; You, Jie; Wu, Min; Li, Shu-Guang; Chen, Bo
2016-07-23
Dietary patterns are linked to obesity, but the gender difference in the association between dietary patterns and obesity remains unclear. We explored this gender difference in a middle-aged and elderly populations in Shanghai. Residents (n = 2046; aged ≥45 years; 968 men and 1078 women) who participated in the Shanghai Food Consumption Survey were studied. Factor analysis of data from four periods of 24-h dietary recalls (across 2012-2014) identified dietary patterns. Height, body weight, and waist circumference were measured to calculate the body mass index. A log binominal model examined the association between dietary patterns and obesity, stratified by gender. Four dietary patterns were identified for both genders: rice staple, wheat staple, snacks, and prudent patterns. The rice staple pattern was associated positively with abdominal obesity in men (prevalence ratio (PR) = 1.358; 95% confidence interval (CI) 1.132-1.639; p = 0.001), but was associated negatively with general obesity in women (PR = 0.745; 95% CI: 0.673-0.807; p = 0.031). Men in the highest quartile of the wheat staple pattern had significantly greater risk of central obesity (PR = 1.331; 95% CI: 1.094-1.627; p = 0.005). There may be gender differences in the association between dietary patterns and obesity in middle-aged and elderly populations in Shanghai, China.
2017-01-01
For many voltage-gated ion channels (VGICs), creation of a properly functioning ion channel requires the formation of specific protein–protein interactions between the transmembrane pore-forming subunits and cystoplasmic accessory subunits. Despite the importance of such protein–protein interactions in VGIC function and assembly, their potential as sites for VGIC modulator development has been largely overlooked. Here, we develop meta-xylyl (m-xylyl) stapled peptides that target a prototypic VGIC high affinity protein–protein interaction, the interaction between the voltage-gated calcium channel (CaV) pore-forming subunit α-interaction domain (AID) and cytoplasmic β-subunit (CaVβ). We show using circular dichroism spectroscopy, X-ray crystallography, and isothermal titration calorimetry that the m-xylyl staples enhance AID helix formation are structurally compatible with native-like AID:CaVβ interactions and reduce the entropic penalty associated with AID binding to CaVβ. Importantly, electrophysiological studies reveal that stapled AID peptides act as effective inhibitors of the CaVα1:CaVβ interaction that modulate CaV function in an CaVβ isoform-selective manner. Together, our studies provide a proof-of-concept demonstration of the use of protein–protein interaction inhibitors to control VGIC function and point to strategies for improved AID-based CaV modulator design. PMID:28278376
Yuan, Ya-Qun; Li, Fan; Meng, Pai; You, Jie; Wu, Min; Li, Shu-Guang; Chen, Bo
2016-01-01
Dietary patterns are linked to obesity, but the gender difference in the association between dietary patterns and obesity remains unclear. We explored this gender difference in a middle-aged and elderly populations in Shanghai. Residents (n = 2046; aged ≥45 years; 968 men and 1078 women) who participated in the Shanghai Food Consumption Survey were studied. Factor analysis of data from four periods of 24-h dietary recalls (across 2012–2014) identified dietary patterns. Height, body weight, and waist circumference were measured to calculate the body mass index. A log binominal model examined the association between dietary patterns and obesity, stratified by gender. Four dietary patterns were identified for both genders: rice staple, wheat staple, snacks, and prudent patterns. The rice staple pattern was associated positively with abdominal obesity in men (prevalence ratio (PR) = 1.358; 95% confidence interval (CI) 1.132–1.639; p = 0.001), but was associated negatively with general obesity in women (PR = 0.745; 95% CI: 0.673–0.807; p = 0.031). Men in the highest quartile of the wheat staple pattern had significantly greater risk of central obesity (PR = 1.331; 95% CI: 1.094–1.627; p = 0.005). There may be gender differences in the association between dietary patterns and obesity in middle-aged and elderly populations in Shanghai, China. PMID:27455322
An algorithm for propagating the square-root covariance matrix in triangular form
NASA Technical Reports Server (NTRS)
Tapley, B. D.; Choe, C. Y.
1976-01-01
A method for propagating the square root of the state error covariance matrix in lower triangular form is described. The algorithm can be combined with any triangular square-root measurement update algorithm to obtain a triangular square-root sequential estimation algorithm. The triangular square-root algorithm compares favorably with the conventional sequential estimation algorithm with regard to computation time.
Frequency-domain beamformers using conjugate gradient techniques for speech enhancement.
Zhao, Shengkui; Jones, Douglas L; Khoo, Suiyang; Man, Zhihong
2014-09-01
A multiple-iteration constrained conjugate gradient (MICCG) algorithm and a single-iteration constrained conjugate gradient (SICCG) algorithm are proposed to realize the widely used frequency-domain minimum-variance-distortionless-response (MVDR) beamformers and the resulting algorithms are applied to speech enhancement. The algorithms are derived based on the Lagrange method and the conjugate gradient techniques. The implementations of the algorithms avoid any form of explicit or implicit autocorrelation matrix inversion. Theoretical analysis establishes formal convergence of the algorithms. Specifically, the MICCG algorithm is developed based on a block adaptation approach and it generates a finite sequence of estimates that converge to the MVDR solution. For limited data records, the estimates of the MICCG algorithm are better than the conventional estimators and equivalent to the auxiliary vector algorithms. The SICCG algorithm is developed based on a continuous adaptation approach with a sample-by-sample updating procedure and the estimates asymptotically converge to the MVDR solution. An illustrative example using synthetic data from a uniform linear array is studied and an evaluation on real data recorded by an acoustic vector sensor array is demonstrated. Performance of the MICCG algorithm and the SICCG algorithm are compared with the state-of-the-art approaches.
Ogawa, Takahiro; Haseyama, Miki
2013-03-01
A missing texture reconstruction method based on an error reduction (ER) algorithm, including a novel estimation scheme of Fourier transform magnitudes is presented in this brief. In our method, Fourier transform magnitude is estimated for a target patch including missing areas, and the missing intensities are estimated by retrieving its phase based on the ER algorithm. Specifically, by monitoring errors converged in the ER algorithm, known patches whose Fourier transform magnitudes are similar to that of the target patch are selected from the target image. In the second approach, the Fourier transform magnitude of the target patch is estimated from those of the selected known patches and their corresponding errors. Consequently, by using the ER algorithm, we can estimate both the Fourier transform magnitudes and phases to reconstruct the missing areas.
Pilot-based parametric channel estimation algorithm for DCO-OFDM-based visual light communications
NASA Astrophysics Data System (ADS)
Qian, Xuewen; Deng, Honggui; He, Hailang
2017-10-01
Due to wide modulation bandwidth in optical communication, multipath channels may be non-sparse and deteriorate communication performance heavily. Traditional compressive sensing-based channel estimation algorithm cannot be employed in this kind of situation. In this paper, we propose a practical parametric channel estimation algorithm for orthogonal frequency division multiplexing (OFDM)-based visual light communication (VLC) systems based on modified zero correlation code (ZCC) pair that has the impulse-like correlation property. Simulation results show that the proposed algorithm achieves better performances than existing least squares (LS)-based algorithm in both bit error ratio (BER) and frequency response estimation.
Development of advanced techniques for rotorcraft state estimation and parameter identification
NASA Technical Reports Server (NTRS)
Hall, W. E., Jr.; Bohn, J. G.; Vincent, J. H.
1980-01-01
An integrated methodology for rotorcraft system identification consists of rotorcraft mathematical modeling, three distinct data processing steps, and a technique for designing inputs to improve the identifiability of the data. These elements are as follows: (1) a Kalman filter smoother algorithm which estimates states and sensor errors from error corrupted data. Gust time histories and statistics may also be estimated; (2) a model structure estimation algorithm for isolating a model which adequately explains the data; (3) a maximum likelihood algorithm for estimating the parameters and estimates for the variance of these estimates; and (4) an input design algorithm, based on a maximum likelihood approach, which provides inputs to improve the accuracy of parameter estimates. Each step is discussed with examples to both flight and simulated data cases.
Detecting Anomalies in Process Control Networks
NASA Astrophysics Data System (ADS)
Rrushi, Julian; Kang, Kyoung-Don
This paper presents the estimation-inspection algorithm, a statistical algorithm for anomaly detection in process control networks. The algorithm determines if the payload of a network packet that is about to be processed by a control system is normal or abnormal based on the effect that the packet will have on a variable stored in control system memory. The estimation part of the algorithm uses logistic regression integrated with maximum likelihood estimation in an inductive machine learning process to estimate a series of statistical parameters; these parameters are used in conjunction with logistic regression formulas to form a probability mass function for each variable stored in control system memory. The inspection part of the algorithm uses the probability mass functions to estimate the normalcy probability of a specific value that a network packet writes to a variable. Experimental results demonstrate that the algorithm is very effective at detecting anomalies in process control networks.
Robust image modeling techniques with an image restoration application
NASA Astrophysics Data System (ADS)
Kashyap, Rangasami L.; Eom, Kie-Bum
1988-08-01
A robust parameter-estimation algorithm for a nonsymmetric half-plane (NSHP) autoregressive model, where the driving noise is a mixture of a Gaussian and an outlier process, is presented. The convergence of the estimation algorithm is proved. An algorithm to estimate parameters and original image intensity simultaneously from the impulse-noise-corrupted image, where the model governing the image is not available, is also presented. The robustness of the parameter estimates is demonstrated by simulation. Finally, an algorithm to restore realistic images is presented. The entire image generally does not obey a simple image model, but a small portion (e.g., 8 x 8) of the image is assumed to obey an NSHP model. The original image is divided into windows and the robust estimation algorithm is applied for each window. The restoration algorithm is tested by comparing it to traditional methods on several different images.
ERIC Educational Resources Information Center
Yang, Ji Seung; Cai, Li
2014-01-01
The main purpose of this study is to improve estimation efficiency in obtaining maximum marginal likelihood estimates of contextual effects in the framework of nonlinear multilevel latent variable model by adopting the Metropolis-Hastings Robbins-Monro algorithm (MH-RM). Results indicate that the MH-RM algorithm can produce estimates and standard…
NASA Technical Reports Server (NTRS)
Yang, Song; Olson, William S.; Wang, Jian-Jian; Bell, Thomas L.; Smith, Eric A.; Kummerow, Christian D.
2006-01-01
Rainfall rate estimates from spaceborne microwave radiometers are generally accepted as reliable by a majority of the atmospheric science community. One of the Tropical Rainfall Measuring Mission (TRMM) facility rain-rate algorithms is based upon passive microwave observations from the TRMM Microwave Imager (TMI). In Part I of this series, improvements of the TMI algorithm that are required to introduce latent heating as an additional algorithm product are described. Here, estimates of surface rain rate, convective proportion, and latent heating are evaluated using independent ground-based estimates and satellite products. Instantaneous, 0.5 deg. -resolution estimates of surface rain rate over ocean from the improved TMI algorithm are well correlated with independent radar estimates (r approx. 0.88 over the Tropics), but bias reduction is the most significant improvement over earlier algorithms. The bias reduction is attributed to the greater breadth of cloud-resolving model simulations that support the improved algorithm and the more consistent and specific convective/stratiform rain separation method utilized. The bias of monthly 2.5 -resolution estimates is similarly reduced, with comparable correlations to radar estimates. Although the amount of independent latent heating data is limited, TMI-estimated latent heating profiles compare favorably with instantaneous estimates based upon dual-Doppler radar observations, and time series of surface rain-rate and heating profiles are generally consistent with those derived from rawinsonde analyses. Still, some biases in profile shape are evident, and these may be resolved with (a) additional contextual information brought to the estimation problem and/or (b) physically consistent and representative databases supporting the algorithm. A model of the random error in instantaneous 0.5 deg. -resolution rain-rate estimates appears to be consistent with the levels of error determined from TMI comparisons with collocated radar. Error model modifications for nonraining situations will be required, however. Sampling error represents only a portion of the total error in monthly 2.5 -resolution TMI estimates; the remaining error is attributed to random and systematic algorithm errors arising from the physical inconsistency and/or nonrepresentativeness of cloud-resolving-model-simulated profiles that support the algorithm.
Behboo, R; Zanella, S; Ruffolo, C; Vafai, M; Marino, F; Scarpa, M
2011-06-01
This study quantified prospectively the amount of rectal wall removed during stapled haemorrhoidopexy and assessed its effect on ano-rectal function and health-related quality of life. Thirty-three consecutive patients who underwent stapled haemorrhoidopexy for second- or third- degree haemorrhoids, or for failed medical treatment, in the Department of Surgery and Gastroenterological Sciences at the University of Padova were included. All patients were assessed preoperatively and postoperatively using a structured questionnaire to determine the number of defecations per week, incomplete defecations, time taken to defecate any difficulty in defecating, soiling, the use of drugs and continence. All patients were reassessed at 1 and 2 weeks and at 30 days after the procedure using the Cleveland Global Quality of Life (CGQL) questionnaire. All patients underwent preoperative and postoperative ano-rectal manometry at least 30 days after stapled haemorrhoidopexy. The median surface area of the resected rectal wall was 10.5 (range, 9-15) mm(2) and the median thickness was 3 (range, 2-4) mm. Muscle tissue was included in all specimens. The median thickness of the resected rectal wall correlated inversely with the rectal volume when the recto-anal inhibitory reflex (RAIR) was initiated during postoperative manometry (ρ = -0.50, P = 0.07). A significant, direct correlation was found between the surface area of the resected rectal wall and the rectal volume during postoperative manometry (ρ = 0.53, P = 0.08) and the use of analgesic drugs after 2 weeks (ρ = 0.63, P = 0.04). Significant correlations were found between being female and postoperative resting pressure (ρ = -0.74, P < 0.01), squeeze pressure (ρ = -0.64, P = 0.01) and maximum tolerated volume (ρ = -0.78, P < 0.01). Stapled haemorrhoidopexy is safe and effective. The thicker the resected rectal wall, the lower the volume of initiation of the RAIR. © 2011 The Authors. Colorectal Disease © 2011 The Association of Coloproctology of Great Britain and Ireland.
Cruz, José Vinicius; Regadas, Francisco Sergio P; Murad-Regadas, Sthela Maria; Rodrigues, Lusmar Veras; Benicio, Fernando; Leal, Rogério; Carvalho, César G; Fernandes, Margarete; Roche, Lucimar M C; Miranda, Antônio Carlos; Câmara, Lucia; Pereira, Joaquim Costa; Parra, Antonio Mallén; Leal, Vilmar Moura
2011-01-01
Since anorectocele is usually associated with mucosa prolapse and/or rectal intussusceptions, it was developed a stapled surgical technique using one circular stapler. To report the results of Transanal Repair of Rectocele and Rectal Mucosectomy with one Circular Stapler (TRREMS procedure) in the treatment of anorectocele with mucosa prolapse in a prospective multicenter trial. It was conducted by 14 surgeons and included 75 female patients, mean aged 49.6 years, with symptoms of obstructed defecation due to grade 2 (26.7%) and grade 3 (73.3%) anorectocele associated with mucosa prolapse and/or rectal intussusception (52.0%) and an average validated Wexner constipation score of 16. All patients were evaluated by a proctological examination, cinedefecography, anal manometry and colonic transit time. The TRREMS procedure consists of the manual removal of the rectocele wall with circumferential rectal mucosectomy performed with a circular stapler. The mean follow-up time was 21 months. All patients presented obstructed defecation and they persisted with symptoms despite conservative treatment. The mean operative time was 42 minutes. In 13 (17.3%) patients, bleeding from the stapled line required hemostatic suture. Stapling was incomplete in 2 (2.6%). Forty-nine patients (65.3%) required 1 hospitalization day, the remainder (34.7%) 2 days. Postoperatively, 3 (4.0%) patients complained of persistent rectal pain and 7 (9.3%) developed stricture on the stapled suture subsequently treated by stricturectomy under anesthesia (n = 1), endoscopic stricturectomy with hot biopsy forceps (n = 3) and digital dilatation (n = 3). Postoperative cinedefecography showed residual grade I anorectoceles in 8 (10.6%). The mean Wexner constipation score decreased significantly from 16 to 4 (0-4: n = 68) (6: n = 6) (7: n = 1) (P<0.0001). Current trial results suggest that TRREMS procedure is a safe and effective technique for the treatment of anorectocele associated with mucosa prolapse. The stapling technique is low-cost as requires the use of a single circular stapler.
Real-time optical flow estimation on a GPU for a skied-steered mobile robot
NASA Astrophysics Data System (ADS)
Kniaz, V. V.
2016-04-01
Accurate egomotion estimation is required for mobile robot navigation. Often the egomotion is estimated using optical flow algorithms. For an accurate estimation of optical flow most of modern algorithms require high memory resources and processor speed. However simple single-board computers that control the motion of the robot usually do not provide such resources. On the other hand, most of modern single-board computers are equipped with an embedded GPU that could be used in parallel with a CPU to improve the performance of the optical flow estimation algorithm. This paper presents a new Z-flow algorithm for efficient computation of an optical flow using an embedded GPU. The algorithm is based on the phase correlation optical flow estimation and provide a real-time performance on a low cost embedded GPU. The layered optical flow model is used. Layer segmentation is performed using graph-cut algorithm with a time derivative based energy function. Such approach makes the algorithm both fast and robust in low light and low texture conditions. The algorithm implementation for a Raspberry Pi Model B computer is discussed. For evaluation of the algorithm the computer was mounted on a Hercules mobile skied-steered robot equipped with a monocular camera. The evaluation was performed using a hardware-in-the-loop simulation and experiments with Hercules mobile robot. Also the algorithm was evaluated using KITTY Optical Flow 2015 dataset. The resulting endpoint error of the optical flow calculated with the developed algorithm was low enough for navigation of the robot along the desired trajectory.
Efficient algorithms for single-axis attitude estimation
NASA Technical Reports Server (NTRS)
Shuster, M. D.
1981-01-01
The computationally efficient algorithms determine attitude from the measurement of art lengths and dihedral angles. The dependence of these algorithms on the solution of trigonometric equations was reduced. Both single time and batch estimators are presented along with the covariance analysis of each algorithm.
Brain tissue segmentation based on DTI data
Liu, Tianming; Li, Hai; Wong, Kelvin; Tarokh, Ashley; Guo, Lei; Wong, Stephen T.C.
2008-01-01
We present a method for automated brain tissue segmentation based on the multi-channel fusion of diffusion tensor imaging (DTI) data. The method is motivated by the evidence that independent tissue segmentation based on DTI parametric images provides complementary information of tissue contrast to the tissue segmentation based on structural MRI data. This has important applications in defining accurate tissue maps when fusing structural data with diffusion data. In the absence of structural data, tissue segmentation based on DTI data provides an alternative means to obtain brain tissue segmentation. Our approach to the tissue segmentation based on DTI data is to classify the brain into two compartments by utilizing the tissue contrast existing in a single channel. Specifically, because the apparent diffusion coefficient (ADC) values in the cerebrospinal fluid (CSF) are more than twice that of gray matter (GM) and white matter (WM), we use ADC images to distinguish CSF and non-CSF tissues. Additionally, fractional anisotropy (FA) images are used to separate WM from non-WM tissues, as highly directional white matter structures have much larger fractional anisotropy values. Moreover, other channels to separate tissue are explored, such as eigenvalues of the tensor, relative anisotropy (RA), and volume ratio (VR). We developed an approach based on the Simultaneous Truth and Performance Level Estimation (STAPLE) algorithm that combines these two-class maps to obtain a complete tissue segmentation map of CSF, GM, and WM. Evaluations are provided to demonstrate the performance of our approach. Experimental results of applying this approach to brain tissue segmentation and deformable registration of DTI data and spoiled gradient-echo (SPGR) data are also provided. PMID:17804258
Contour-based object orientation estimation
NASA Astrophysics Data System (ADS)
Alpatov, Boris; Babayan, Pavel
2016-04-01
Real-time object orientation estimation is an actual problem of computer vision nowadays. In this paper we propose an approach to estimate an orientation of objects lacking axial symmetry. Proposed algorithm is intended to estimate orientation of a specific known 3D object, so 3D model is required for learning. The proposed orientation estimation algorithm consists of 2 stages: learning and estimation. Learning stage is devoted to the exploring of studied object. Using 3D model we can gather set of training images by capturing 3D model from viewpoints evenly distributed on a sphere. Sphere points distribution is made by the geosphere principle. It minimizes the training image set. Gathered training image set is used for calculating descriptors, which will be used in the estimation stage of the algorithm. The estimation stage is focusing on matching process between an observed image descriptor and the training image descriptors. The experimental research was performed using a set of images of Airbus A380. The proposed orientation estimation algorithm showed good accuracy (mean error value less than 6°) in all case studies. The real-time performance of the algorithm was also demonstrated.
Photoreactive Stapled BH3 Peptides to Dissect the BCL-2 Family Interactome
Braun, Craig R.; Mintseris, Julian; Gavathiotis, Evripidis; Bird, Gregory H.; Gygi, Steven P.; Walensky, Loren D.
2010-01-01
SUMMARY Defining protein interactions forms the basis for discovery of biological pathways, disease mechanisms, and opportunities for therapeutic intervention. To harness the robust binding affinity and selectivity of structured peptides for interactome discovery, we engineered photoreactive stapled BH3 peptide helices that covalently capture their physiologic BCL-2 family targets. The crosslinking α-helices covalently trap both static and dynamic protein interactors, and enable rapid identification of interaction sites, providing a critical link between interactome discovery and targeted drug design. PMID:21168768
Recent evidence has established a role for the small GTPase RAB25, as well as related effector proteins, in enacting both pro-oncogenic and anti-oncogenic phenotypes in specific cellular contexts. Here we report the development of all-hydrocarbon stabilized peptides derived from the RAB-binding FIP-family of proteins to target RAB25. Relative to unmodified peptides, optimized stapled peptides exhibit increased structural stability, binding affinity, cell permeability, and inhibition of RAB25:FIP complex formation.
Noise Hazard Evaluation Sound Level Data on Noise Sources
1975-01-01
Saw, Root Woodworking 43-20-J 102 16. Construction Saw, DeWalt Industrial 2185A 96 17. Cross-Cut Sw, Automatic 1-H 94 18, Cross-Cut Saw, DeWalt 3561...Saw, GM Diehr 750 92 53. Rip Saw, Wabach Industrial 750 97 59. Rip Saw, Yates American B. 102 60. Router: Black & Decker 118 61. Ruuter, Rockwell 150B...13. Sander, Disk, National-Detroit Dual Action 100 14. Stapler , Senco Mll 94* 15. Stapling Gun, Bostich II 105* 16. Stapling Gun, Bostich III 104* 17
The Boer-Mulders Transverse Momentum Distribution in the Pion and its Evolution in Lattice QCD
NASA Astrophysics Data System (ADS)
Engelhardt, M.; Musch, B.; Hägler, P.; Schäfer, A.; Negele, J.
2015-02-01
Starting from a definition of transverse momentum-dependent parton distributions (TMDs) in terms of hadronic matrix elements of a quark bilocal operator containing a staple-shaped gauge link, selected TMD observables can be evaluated within Lattice QCD. A TMD ratio describing the Boer-Mulders effect in the pion is investigated, with a particular emphasis on its evolution as a function of a Collins-Soper-type parameter which quantifies the proximity of the staple-shaped gauge links to the light cone.
Lee, Jung Keun; Park, Edward J.; Robinovitch, Stephen N.
2012-01-01
This paper proposes a Kalman filter-based attitude (i.e., roll and pitch) estimation algorithm using an inertial sensor composed of a triaxial accelerometer and a triaxial gyroscope. In particular, the proposed algorithm has been developed for accurate attitude estimation during dynamic conditions, in which external acceleration is present. Although external acceleration is the main source of the attitude estimation error and despite the need for its accurate estimation in many applications, this problem that can be critical for the attitude estimation has not been addressed explicitly in the literature. Accordingly, this paper addresses the combined estimation problem of the attitude and external acceleration. Experimental tests were conducted to verify the performance of the proposed algorithm in various dynamic condition settings and to provide further insight into the variations in the estimation accuracy. Furthermore, two different approaches for dealing with the estimation problem during dynamic conditions were compared, i.e., threshold-based switching approach versus acceleration model-based approach. Based on an external acceleration model, the proposed algorithm was capable of estimating accurate attitudes and external accelerations for short accelerated periods, showing its high effectiveness during short-term fast dynamic conditions. Contrariwise, when the testing condition involved prolonged high external accelerations, the proposed algorithm exhibited gradually increasing errors. However, as soon as the condition returned to static or quasi-static conditions, the algorithm was able to stabilize the estimation error, regaining its high estimation accuracy. PMID:22977288
Krska, Z; Kvasnièka, J; Faltýn, J; Schmidt, D; Sváb, J; Kormanová, K; Hubík, J
2003-11-01
To compare by prospective randomised trial the postoperative tissue reaction of stapled vs. conventional haemorrhoidectomy. Fifty patients with stage III haemorrhoids underwent surgery for haemorrhoids. Group 1 (n = 25) had the Milligan-Morgan procedure; Group 2 (n = 25) had a stapled haemorrhoidectomy. All patients underwent measurements of endothelial dysfunction markers including E-selectin, P-selectin and intercellular adhesion molecule (ICAM). Acute-phase proteins including C-reactive protein, orosomucoid and fibrinogen were also measured. Estimations were made prior to surgery, immediately afterward surgery and on the first and fifth postoperative days. Assessment of clinical outcome was made one month after the surgery. There was a postoperative increase of acute-phase reactants in both groups. The patterns of the cures of the monitored parameters appeared similar in both groups. Lower values were found in Group 1, but the difference was not statistically significant except the level of fibrinogen on day 5, which was significantly higher in Group 2. E-selectin, P-selectin and ICAM showed similar time curves. Statistical analysis found the differences to be significant only when individual days were compared and not for the types of surgery. Raised ICAM and P-selectin on the fifth postoperative day was found in both groups. In Group 1, pain assessment by patients remained in the lower part of the pain rating scale, while in Group 2 it did not start declining until one week after surgery and became normal in the third to fourth weeks. In Group 1, the duration of hospitalization and the duration of incapacity for work were 50% of the values in Group 2. Patients having stapled haemorrhoidectomy have less pain and experience more rapid recovery when compared to classical haemorroidectomy. This was mirrored by the acute-phase protein CRP and fibrinogen levels postoperatively. There was no significant difference in other acute-phase reactants monitored, nor was there any difference in parameters of endothelial dysfunction. The techniques differ in extent of pain and duration of hospital stay and incapacity for work.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kagie, Matthew J.; Lanterman, Aaron D.
2017-12-01
This paper addresses parameter estimation for an optical transient signal when the received data has been right-censored. We develop an expectation-maximization (EM) algorithm to estimate the amplitude of a Poisson intensity with a known shape in the presence of additive background counts, where the measurements are subject to saturation effects. We compare the results of our algorithm with those of an EM algorithm that is unaware of the censoring.
Liu, Hong; Wang, Jie; Xu, Xiangyang; Song, Enmin; Wang, Qian; Jin, Renchao; Hung, Chih-Cheng; Fei, Baowei
2014-11-01
A robust and accurate center-frequency (CF) estimation (RACE) algorithm for improving the performance of the local sine-wave modeling (SinMod) method, which is a good motion estimation method for tagged cardiac magnetic resonance (MR) images, is proposed in this study. The RACE algorithm can automatically, effectively and efficiently produce a very appropriate CF estimate for the SinMod method, under the circumstance that the specified tagging parameters are unknown, on account of the following two key techniques: (1) the well-known mean-shift algorithm, which can provide accurate and rapid CF estimation; and (2) an original two-direction-combination strategy, which can further enhance the accuracy and robustness of CF estimation. Some other available CF estimation algorithms are brought out for comparison. Several validation approaches that can work on the real data without ground truths are specially designed. Experimental results on human body in vivo cardiac data demonstrate the significance of accurate CF estimation for SinMod, and validate the effectiveness of RACE in facilitating the motion estimation performance of SinMod. Copyright © 2014 Elsevier Inc. All rights reserved.
Creel, Scott; Creel, Michael
2009-11-01
1. Sampling error in annual estimates of population size creates two widely recognized problems for the analysis of population growth. First, if sampling error is mistakenly treated as process error, one obtains inflated estimates of the variation in true population trajectories (Staples, Taper & Dennis 2004). Second, treating sampling error as process error is thought to overestimate the importance of density dependence in population growth (Viljugrein et al. 2005; Dennis et al. 2006). 2. In ecology, state-space models are used to account for sampling error when estimating the effects of density and other variables on population growth (Staples et al. 2004; Dennis et al. 2006). In econometrics, regression with instrumental variables is a well-established method that addresses the problem of correlation between regressors and the error term, but requires fewer assumptions than state-space models (Davidson & MacKinnon 1993; Cameron & Trivedi 2005). 3. We used instrumental variables to account for sampling error and fit a generalized linear model to 472 annual observations of population size for 35 Elk Management Units in Montana, from 1928 to 2004. We compared this model with state-space models fit with the likelihood function of Dennis et al. (2006). We discuss the general advantages and disadvantages of each method. Briefly, regression with instrumental variables is valid with fewer distributional assumptions, but state-space models are more efficient when their distributional assumptions are met. 4. Both methods found that population growth was negatively related to population density and winter snow accumulation. Summer rainfall and wolf (Canis lupus) presence had much weaker effects on elk (Cervus elaphus) dynamics [though limitation by wolves is strong in some elk populations with well-established wolf populations (Creel et al. 2007; Creel & Christianson 2008)]. 5. Coupled with predictions for Montana from global and regional climate models, our results predict a substantial reduction in the limiting effect of snow accumulation on Montana elk populations in the coming decades. If other limiting factors do not operate with greater force, population growth rates would increase substantially.
NASA Astrophysics Data System (ADS)
Polack, J. K.; Flaska, M.; Enqvist, A.; Sosa, C. S.; Lawrence, C. C.; Pozzi, S. A.
2015-09-01
Organic scintillators are frequently used for measurements that require sensitivity to both photons and fast neutrons because of their pulse shape discrimination capabilities. In these measurement scenarios, particle identification is commonly handled using the charge-integration pulse shape discrimination method. This method works particularly well for high-energy depositions, but is prone to misclassification for relatively low-energy depositions. A novel algorithm has been developed for automatically performing charge-integration pulse shape discrimination in a consistent and repeatable manner. The algorithm is able to estimate the photon and neutron misclassification corresponding to the calculated discrimination parameters, and is capable of doing so using only the information measured by a single organic scintillator. This paper describes the algorithm and assesses its performance by comparing algorithm-estimated misclassification to values computed via a more traditional time-of-flight estimation. A single data set was processed using four different low-energy thresholds: 40, 60, 90, and 120 keVee. Overall, the results compared well between the two methods; in most cases, the algorithm-estimated values fell within the uncertainties of the TOF-estimated values.
The Gut Microbiota, Food Science, and Human Nutrition: A Timely Marriage.
Barratt, Michael J; Lebrilla, Carlito; Shapiro, Howard-Yana; Gordon, Jeffrey I
2017-08-09
Analytic advances are enabling more precise definitions of the molecular composition of key food staples incorporated into contemporary diets and how the nutrient landscapes of these staples vary as a function of cultivar and food processing methods. This knowledge, combined with insights about the interrelationship between consumer microbiota configurations and biotransformation of food ingredients, should have a number of effects on agriculture, food production, and strategies for improving the nutritional value of foods and health status. These effects include decision-making about which cultivars of current or future food staples to incorporate into existing and future food systems, and which components of waste streams from current or future food manufacturing processes have nutritional value that is worth capturing. They can also guide which technologies should be applied, or need to be developed, to produce foods that support efficient microbial biotransformation of their ingredients into metabolic products that sustain health. Copyright © 2017 Elsevier Inc. All rights reserved.
Anesthetic management of the SRS™ Endoscopic Stapling System for gastro-esophageal reflux disease.
Topuz, Ufuk; Umutoglu, Tarik; Bakan, Mefkur; Ozturk, Erdogan
2013-01-14
The SRS(TM) Endoscopic Stapling System (Medigus, Tel Aviv, Israel) is a new tool capable of creating a totally endoscopic fundoplication, combined with an endoscope, endoscopic ultrasound and a surgical stapler. SRS(TM) endoscopic stapling for gastro-esophageal reflux disease is a minimally invasive, outpatient procedure, which requires general anesthesia with positive-pressure ventilation. Keeping the patient on positive end-expiratory pressure (PEEP) may minimize the pressure gradient between the esophagus and the mediastinum, as well as help to prevent air from leaking around the screws and causing pneumomediastinum. In addition, in patients with hiatal hernia, higher PEEP levels may be required to increase intra-thoracic pressure and to force the stomach to slide into the abdomen for ease of endoscopy. We advise smoother emergence from anesthesia, taking precautions for retching, postoperative nausea and vomiting (PONV), while coughing and gagging during extubation and PONV may affect the success of the procedure. Total intravenous anesthesia with propofol and remifentanil seems to be a good choice for these reasons.
Circular stapler introducer: a novel device to facilitate stapled colorectal anastomosis.
Guweidhi, Ahmed; Steffen, Rudolf; Metzger, Alejandro; Teuscher, Jürg; Flückiger, Petra; Z'graggen, Kaspar
2009-04-01
A circular stapler introducer was developed to protect the head of the circular stapler and enable atraumatic introduction and advancement of the circular stapler without interfering with the application and safety of an anastomosis. In a Phase I prospective study, we tested the feasibility and safety of the novel circular stapler introducer device in 60 consecutive patients undergoing left-sided colorectal resections. The median distance of the anastomoses from the anal verge was 12 cm (7-20, n = 60). Total morbidity was 15 percent. No mortality was observed. Handling of the circular stapler introducer was considered nonproblematic by all surgeons who participated in the study. No interference of the circular stapler introducer with the circular stapling devices used was encountered. The advancement of the stapler into the end of the colorectal stump was always possible with the aid of the circular stapler introducer. Use of the circular stapler introducer facilitates the double-stapling technique of colorectal anastomosis. The circular stapler introducer has great potential and should be tested in larger studies.
Oscillometric Blood Pressure Estimation: Past, Present, and Future.
Forouzanfar, Mohamad; Dajani, Hilmi R; Groza, Voicu Z; Bolic, Miodrag; Rajan, Sreeraman; Batkin, Izmail
2015-01-01
The use of automated blood pressure (BP) monitoring is growing as it does not require much expertise and can be performed by patients several times a day at home. Oscillometry is one of the most common measurement methods used in automated BP monitors. A review of the literature shows that a large variety of oscillometric algorithms have been developed for accurate estimation of BP but these algorithms are scattered in many different publications or patents. Moreover, considering that oscillometric devices dominate the home BP monitoring market, little effort has been made to survey the underlying algorithms that are used to estimate BP. In this review, a comprehensive survey of the existing oscillometric BP estimation algorithms is presented. The survey covers a broad spectrum of algorithms including the conventional maximum amplitude and derivative oscillometry as well as the recently proposed learning algorithms, model-based algorithms, and algorithms that are based on analysis of pulse morphology and pulse transit time. The aim is to classify the diverse underlying algorithms, describe each algorithm briefly, and discuss their advantages and disadvantages. This paper will also review the artifact removal techniques in oscillometry and the current standards for the automated BP monitors.
NASA Astrophysics Data System (ADS)
Chang, Yaping; Qin, Dahe; Ding, Yongjian; Zhao, Qiudong; Zhang, Shiqiang
2018-06-01
The long-term change of evapotranspiration (ET) is crucial for managing water resources in areas with extreme climates, such as the Tibetan Plateau (TP). This study proposed a modified algorithm for estimating ET based on the MOD16 algorithm on a global scale over alpine meadow on the TP in China. Wind speed and vegetation height were integrated to estimate aerodynamic resistance, while the temperature and moisture constraints for stomatal conductance were revised based on the technique proposed by Fisher et al. (2008). Moreover, Fisher's method for soil evaporation was adopted to reduce the uncertainty in soil evaporation estimation. Five representative alpine meadow sites on the TP were selected to investigate the performance of the modified algorithm. Comparisons were made between the ET observed using the Eddy Covariance (EC) and estimated using both the original and modified algorithms. The results revealed that the modified algorithm performed better than the original MOD16 algorithm with the coefficient of determination (R2) increasing from 0.26 to 0.68, and root mean square error (RMSE) decreasing from 1.56 to 0.78 mm d-1. The modified algorithm performed slightly better with a higher R2 (0.70) and lower RMSE (0.61 mm d-1) for after-precipitation days than for non-precipitation days at Suli site. Contrarily, better results were obtained for non-precipitation days than for after-precipitation days at Arou, Tanggula, and Hulugou sites, indicating that the modified algorithm may be more suitable for estimating ET for non-precipitation days with higher accuracy than for after-precipitation days, which had large observation errors. The comparisons between the modified algorithm and two mainstream methods suggested that the modified algorithm could produce high accuracy ET over the alpine meadow sites on the TP.
SDR input power estimation algorithms
NASA Astrophysics Data System (ADS)
Briones, J. C.; Nappier, J. M.
The General Dynamics (GD) S-Band software defined radio (SDR) in the Space Communications and Navigation (SCAN) Testbed on the International Space Station (ISS) provides experimenters an opportunity to develop and demonstrate experimental waveforms in space. The SDR has an analog and a digital automatic gain control (AGC) and the response of the AGCs to changes in SDR input power and temperature was characterized prior to the launch and installation of the SCAN Testbed on the ISS. The AGCs were used to estimate the SDR input power and SNR of the received signal and the characterization results showed a nonlinear response to SDR input power and temperature. In order to estimate the SDR input from the AGCs, three algorithms were developed and implemented on the ground software of the SCAN Testbed. The algorithms include a linear straight line estimator, which used the digital AGC and the temperature to estimate the SDR input power over a narrower section of the SDR input power range. There is a linear adaptive filter algorithm that uses both AGCs and the temperature to estimate the SDR input power over a wide input power range. Finally, an algorithm that uses neural networks was designed to estimate the input power over a wide range. This paper describes the algorithms in detail and their associated performance in estimating the SDR input power.
SDR Input Power Estimation Algorithms
NASA Technical Reports Server (NTRS)
Nappier, Jennifer M.; Briones, Janette C.
2013-01-01
The General Dynamics (GD) S-Band software defined radio (SDR) in the Space Communications and Navigation (SCAN) Testbed on the International Space Station (ISS) provides experimenters an opportunity to develop and demonstrate experimental waveforms in space. The SDR has an analog and a digital automatic gain control (AGC) and the response of the AGCs to changes in SDR input power and temperature was characterized prior to the launch and installation of the SCAN Testbed on the ISS. The AGCs were used to estimate the SDR input power and SNR of the received signal and the characterization results showed a nonlinear response to SDR input power and temperature. In order to estimate the SDR input from the AGCs, three algorithms were developed and implemented on the ground software of the SCAN Testbed. The algorithms include a linear straight line estimator, which used the digital AGC and the temperature to estimate the SDR input power over a narrower section of the SDR input power range. There is a linear adaptive filter algorithm that uses both AGCs and the temperature to estimate the SDR input power over a wide input power range. Finally, an algorithm that uses neural networks was designed to estimate the input power over a wide range. This paper describes the algorithms in detail and their associated performance in estimating the SDR input power.
Charlton, Peter H; Bonnici, Timothy; Tarassenko, Lionel; Clifton, David A; Beale, Richard; Watkinson, Peter J
2016-04-01
Over 100 algorithms have been proposed to estimate respiratory rate (RR) from the electrocardiogram (ECG) and photoplethysmogram (PPG). As they have never been compared systematically it is unclear which algorithm performs the best. Our primary aim was to determine how closely algorithms agreed with a gold standard RR measure when operating under ideal conditions. Secondary aims were: (i) to compare algorithm performance with IP, the clinical standard for continuous respiratory rate measurement in spontaneously breathing patients; (ii) to compare algorithm performance when using ECG and PPG; and (iii) to provide a toolbox of algorithms and data to allow future researchers to conduct reproducible comparisons of algorithms. Algorithms were divided into three stages: extraction of respiratory signals, estimation of RR, and fusion of estimates. Several interchangeable techniques were implemented for each stage. Algorithms were assembled using all possible combinations of techniques, many of which were novel. After verification on simulated data, algorithms were tested on data from healthy participants. RRs derived from ECG, PPG and IP were compared to reference RRs obtained using a nasal-oral pressure sensor using the limits of agreement (LOA) technique. 314 algorithms were assessed. Of these, 270 could operate on either ECG or PPG, and 44 on only ECG. The best algorithm had 95% LOAs of -4.7 to 4.7 bpm and a bias of 0.0 bpm when using the ECG, and -5.1 to 7.2 bpm and 1.0 bpm when using PPG. IP had 95% LOAs of -5.6 to 5.2 bpm and a bias of -0.2 bpm. Four algorithms operating on ECG performed better than IP. All high-performing algorithms consisted of novel combinations of time domain RR estimation and modulation fusion techniques. Algorithms performed better when using ECG than PPG. The toolbox of algorithms and data used in this study are publicly available.
Charlton, Peter H; Bonnici, Timothy; Tarassenko, Lionel; Clifton, David A; Beale, Richard; Watkinson, Peter J
2016-01-01
Abstract Over 100 algorithms have been proposed to estimate respiratory rate (RR) from the electrocardiogram (ECG) and photoplethysmogram (PPG). As they have never been compared systematically it is unclear which algorithm performs the best. Our primary aim was to determine how closely algorithms agreed with a gold standard RR measure when operating under ideal conditions. Secondary aims were: (i) to compare algorithm performance with IP, the clinical standard for continuous respiratory rate measurement in spontaneously breathing patients; (ii) to compare algorithm performance when using ECG and PPG; and (iii) to provide a toolbox of algorithms and data to allow future researchers to conduct reproducible comparisons of algorithms. Algorithms were divided into three stages: extraction of respiratory signals, estimation of RR, and fusion of estimates. Several interchangeable techniques were implemented for each stage. Algorithms were assembled using all possible combinations of techniques, many of which were novel. After verification on simulated data, algorithms were tested on data from healthy participants. RRs derived from ECG, PPG and IP were compared to reference RRs obtained using a nasal-oral pressure sensor using the limits of agreement (LOA) technique. 314 algorithms were assessed. Of these, 270 could operate on either ECG or PPG, and 44 on only ECG. The best algorithm had 95% LOAs of −4.7 to 4.7 bpm and a bias of 0.0 bpm when using the ECG, and −5.1 to 7.2 bpm and 1.0 bpm when using PPG. IP had 95% LOAs of −5.6 to 5.2 bpm and a bias of −0.2 bpm. Four algorithms operating on ECG performed better than IP. All high-performing algorithms consisted of novel combinations of time domain RR estimation and modulation fusion techniques. Algorithms performed better when using ECG than PPG. The toolbox of algorithms and data used in this study are publicly available. PMID:27027672
Evaluation and Application of Satellite-Based Latent Heating Profile Estimation Methods
NASA Technical Reports Server (NTRS)
Olson, William S.; Grecu, Mircea; Yang, Song; Tao, Wei-Kuo
2004-01-01
In recent years, methods for estimating atmospheric latent heating vertical structure from both passive and active microwave remote sensing have matured to the point where quantitative evaluation of these methods is the next logical step. Two approaches for heating algorithm evaluation are proposed: First, application of heating algorithms to synthetic data, based upon cloud-resolving model simulations, can be used to test the internal consistency of heating estimates in the absence of systematic errors in physical assumptions. Second, comparisons of satellite-retrieved vertical heating structures to independent ground-based estimates, such as rawinsonde-derived analyses of heating, provide an additional test. The two approaches are complementary, since systematic errors in heating indicated by the second approach may be confirmed by the first. A passive microwave and combined passive/active microwave heating retrieval algorithm are evaluated using the described approaches. In general, the passive microwave algorithm heating profile estimates are subject to biases due to the limited vertical heating structure information contained in the passive microwave observations. These biases may be partly overcome by including more environment-specific a priori information into the algorithm s database of candidate solution profiles. The combined passive/active microwave algorithm utilizes the much higher-resolution vertical structure information provided by spaceborne radar data to produce less biased estimates; however, the global spatio-temporal sampling by spaceborne radar is limited. In the present study, the passive/active microwave algorithm is used to construct a more physically-consistent and environment-specific set of candidate solution profiles for the passive microwave algorithm and to help evaluate errors in the passive algorithm s heating estimates. Although satellite estimates of latent heating are based upon instantaneous, footprint- scale data, suppression of random errors requires averaging to at least half-degree resolution. Analysis of mesoscale and larger space-time scale phenomena based upon passive and passive/active microwave heating estimates from TRMM, SSMI, and AMSR data will be presented at the conference.
NASA Astrophysics Data System (ADS)
Mehdinejadiani, Behrouz
2017-08-01
This study represents the first attempt to estimate the solute transport parameters of the spatial fractional advection-dispersion equation using Bees Algorithm. The numerical studies as well as the experimental studies were performed to certify the integrity of Bees Algorithm. The experimental ones were conducted in a sandbox for homogeneous and heterogeneous soils. A detailed comparative study was carried out between the results obtained from Bees Algorithm and those from Genetic Algorithm and LSQNONLIN routines in FracFit toolbox. The results indicated that, in general, the Bees Algorithm much more accurately appraised the sFADE parameters in comparison with Genetic Algorithm and LSQNONLIN, especially in the heterogeneous soil and for α values near to 1 in the numerical study. Also, the results obtained from Bees Algorithm were more reliable than those from Genetic Algorithm. The Bees Algorithm showed the relative similar performances for all cases, while the Genetic Algorithm and the LSQNONLIN yielded different performances for various cases. The performance of LSQNONLIN strongly depends on the initial guess values so that, compared to the Genetic Algorithm, it can more accurately estimate the sFADE parameters by taking into consideration the suitable initial guess values. To sum up, the Bees Algorithm was found to be very simple, robust and accurate approach to estimate the transport parameters of the spatial fractional advection-dispersion equation.
Mehdinejadiani, Behrouz
2017-08-01
This study represents the first attempt to estimate the solute transport parameters of the spatial fractional advection-dispersion equation using Bees Algorithm. The numerical studies as well as the experimental studies were performed to certify the integrity of Bees Algorithm. The experimental ones were conducted in a sandbox for homogeneous and heterogeneous soils. A detailed comparative study was carried out between the results obtained from Bees Algorithm and those from Genetic Algorithm and LSQNONLIN routines in FracFit toolbox. The results indicated that, in general, the Bees Algorithm much more accurately appraised the sFADE parameters in comparison with Genetic Algorithm and LSQNONLIN, especially in the heterogeneous soil and for α values near to 1 in the numerical study. Also, the results obtained from Bees Algorithm were more reliable than those from Genetic Algorithm. The Bees Algorithm showed the relative similar performances for all cases, while the Genetic Algorithm and the LSQNONLIN yielded different performances for various cases. The performance of LSQNONLIN strongly depends on the initial guess values so that, compared to the Genetic Algorithm, it can more accurately estimate the sFADE parameters by taking into consideration the suitable initial guess values. To sum up, the Bees Algorithm was found to be very simple, robust and accurate approach to estimate the transport parameters of the spatial fractional advection-dispersion equation. Copyright © 2017 Elsevier B.V. All rights reserved.
Novel cooperative neural fusion algorithms for image restoration and image fusion.
Xia, Youshen; Kamel, Mohamed S
2007-02-01
To deal with the problem of restoring degraded images with non-Gaussian noise, this paper proposes a novel cooperative neural fusion regularization (CNFR) algorithm for image restoration. Compared with conventional regularization algorithms for image restoration, the proposed CNFR algorithm can relax need of the optimal regularization parameter to be estimated. Furthermore, to enhance the quality of restored images, this paper presents a cooperative neural fusion (CNF) algorithm for image fusion. Compared with existing signal-level image fusion algorithms, the proposed CNF algorithm can greatly reduce the loss of contrast information under blind Gaussian noise environments. The performance analysis shows that the proposed two neural fusion algorithms can converge globally to the robust and optimal image estimate. Simulation results confirm that in different noise environments, the proposed two neural fusion algorithms can obtain a better image estimate than several well known image restoration and image fusion methods.
Analysis of the Command and Control Segment (CCS) attitude estimation algorithm
NASA Technical Reports Server (NTRS)
Stockwell, Catherine
1993-01-01
This paper categorizes the qualitative behavior of the Command and Control Segment (CCS) differential correction algorithm as applied to attitude estimation using simultaneous spin axis sun angle and Earth cord length measurements. The categories of interest are the domains of convergence, divergence, and their boundaries. Three series of plots are discussed that show the dependence of the estimation algorithm on the vehicle radius, the sun/Earth angle, and the spacecraft attitude. Common qualitative dynamics to all three series are tabulated and discussed. Out-of-limits conditions for the estimation algorithm are identified and discussed.
He, Y; Chen, D; Zheng, W
2015-11-12
Specific protein-protein interactions (PPIs) constitute a key underlying mechanism for the presence of a multitude of intracellular signaling pathways, which are essential for the survival of normal and cancer cells. Specific molecular blockers for a crucial PPI would therefore be invaluable tools for an enhanced functional interrogation of the signaling pathway harboring this particular PPI. On the other hand, if a particular PPI is essential for the survival of cancer cells but is absent in or dispensable for the survival of normal cells, its specific molecular blockers could potentially be developed into effective anticancer therapeutics. Due to the flat and extended PPI interface, it would be conceivably difficult for small molecules to achieve an effective blockade, a problem which could be potentially circumvented with peptides or proteins. However, the well-documented proteolytic instability and cellular impermeability of peptides and proteins in general would make their developing into effective intracellular PPI blockers quite a challenge. With the advent of the peptide 'stapling' technology which was demonstrated to be able to stabilize the α-helical conformation of a peptide via bridging two neighboring amino-acid side chains with a 'molecular staple', a linear parent peptide could be transformed into a stronger PPI blocker with enhanced proteolytic stability and cellular permeability. This review will furnish an account on the peptide 'stapling' technology and its exploitation in efforts to achieve an enhanced functional interrogation or manipulation of intracellular signaling pathways especially those that are cancer relevant.
Unexpected involvement of staple leads to redesign of selective bicyclic peptide inhibitor of Grb7
NASA Astrophysics Data System (ADS)
Gunzburg, Menachem J.; Kulkarni, Ketav; Watson, Gabrielle M.; Ambaye, Nigus D.; Del Borgo, Mark P.; Brandt, Rebecca; Pero, Stephanie C.; Perlmutter, Patrick; Wilce, Matthew C. J.; Wilce, Jacqueline A.
2016-06-01
The design of potent and specific peptide inhibitors to therapeutic targets is of enormous utility for both proof-of-concept studies and for the development of potential new therapeutics. Grb7 is a key signaling molecule in the progression of HER2 positive and triple negative breast cancers. Here we report the crystal structure of a stapled bicyclic peptide inhibitor G7-B1 in complex with the Grb7-SH2 domain. This revealed an unexpected binding mode of the peptide, in which the staple forms an alternative contact with the surface of the target protein. Based on this structural information, we designed a new series of bicyclic G7 peptides that progressively constrain the starting peptide, to arrive at the G7-B4 peptide that binds with an approximately 2-fold enhanced affinity to the Grb7-SH2 domain (KD = 0.83 μM) compared to G7-B1 and shows low affinity binding to Grb2-, Grb10- and Grb14-SH2 domains (KD > 100 μM). Furthermore, we determined the structure of the G7-B4 bicyclic peptide in complex with the Grb7-SH2 domain, both before and after ring closing metathesis to show that the closed staple is essential to the target interaction. The G7-B4 peptide represents an advance in the development of Grb7 inhibitors and is a classical example of structure aided inhibitor development.
Technique-associated outcomes in horses following large colon resection.
Pezzanite, Lynn M; Hackett, Eileen S
2017-11-01
To compare survival and complications in horses undergoing large colon resection with either sutured end-to-end or stapled functional end-to-end anastomoses. Retrospective cohort study. Twenty-six client-owned horses with gastrointestinal disease. Retrospective data were retrieved from the medical records of 26 horses undergoing colectomy, including 14 horses with sutured end-to-end and 12 horses with stapled functional end-to-end anastomoses, between 2003 and 2016. Records were evaluated for signalment, medical and surgical treatments, and survival to hospital discharge. Long-term follow-up was obtained through owner contact. Continuous variables were compared with Mann-Whitney tests. Fisher's exact testing was used to compare survival to hospital discharge. Survival time was compared by constructing Kaplan-Meier survival curves and performing log-rank curve comparison testing. Mean age of horses undergoing colectomy was 13 years. Reason for colectomy was prophylaxis (12) or salvage (14). Mean surgical time was 169 minutes. Mean hospitalization time was 9 days, which did not differ with anastomosis type (P = .62). Nine of 12 horses undergoing stapled functional end-to-end anastomosis and 12 of 14 horses undergoing sutured end-to-end anastomosis survived to hospital discharge (P = .63). Survival time did not differ with anastomosis technique (P = .35). Short- and long-term survival outcomes are not different between sutured end-to-end or stapled functional end-to-end anastomoses in horses undergoing colectomy. © 2017 The American College of Veterinary Surgeons.
Effect of public symphysiodesis on pelvic development in the skeletally immature greyhound.
Swainson, S W; Conzemius, M G; Riedesel, E A; Smith, G K; Riley, C B
2000-01-01
To evaluate the effect of pubic symphysiodesis (PS) on pelvic development in skeletally immature dogs. Prospective randomized clinical trial. Eight 4 month-old, sexually intact female Greyhounds. Initial PS was performed at 4 months of age using a powered stapling device. Because of failure of the initial surgery, a second PS was performed 1 month later by resecting the pubic symphysis with a rongeur followed by placement of handmade bone staples in four dogs. Sham PS was performed in four control dogs at 4 months of age. Pubic growth rate and pelvic development were evaluated using standard plane radiography and computed tomography. Specific measurements included acetabular ventroversion, Norberg angle, lateral center-edge angle, and pelvic inlet dimensions. Hip distraction indices were determined as well. PS at 4 months of age using a stapling device failed. Pubic symphysiodesis using hand made staples was successful at 5 months of age and did not result in any clinically significant intraoperative or postoperative complications. Pubic symphysiodesis markedly decreased pubic symphysis growth in the treatment group. Hip distraction indices and pelvic inlet circumference, area, and width significantly decreased in treated dogs compared to those in the control group. Acetabular ventroversion was significantly increased in treated dogs compared to those in the control group. PS decreases pelvic canal size, increases acetabular ventroversion, and does not appear to have any clinically significant complications. PS performed in skeletally immature dogs with hip dysplasia may provide an effect similar to a triple pelvic osteotomy and warrants further investigation.
Is hand sewing comparable with stapling for anastomotic leakage after esophagectomy? A meta-analysis
Liu, Quan-Xing; Min, Jia-Xin; Deng, Xu-Feng; Dai, Ji-Gang
2014-01-01
AIM: To compare the outcome of hand sewing and stapling for anastomotic leakage after esophagectomy. METHODS: A rigorous study protocol was established according to the recommendations of the Cochrane Collaboration. An electronic database search, hand search, and reference search were used to retrieve all randomized controlled trials that compared hand-sewn and mechanical esophagogastric anastomoses. RESULTS: This study included 15 randomized controlled trials with a total of 2337 patients. The results revealed that there was no significant difference in the incidence of anastomotic leakage between the methods [relative risk (RR) = 0.77, 95% confidence interval (CI): 0.57-1.04; P = 0.09], but a subgroup analysis yielded a significant difference for the sutured layer and year of publication (Ps < 0.05). There was also no significant difference in the incidence of postoperative mortality (RR = 1.52, 95%CI: 0.97-2.40; P = 0.07). However, the anastomotic strictures rate was increased in the stapler group compared with the hand-sewn group (RR = 1.45, 95%CI: 1.11-1.91; P < 0.01) in the end-to-side subgroup, while the incidence of anastomotic strictures was decreased (RR = 0.34, 95%CI: 0.16-0.76; P < 0.01) in the side-to-side subgroup. CONCLUSION: The stapler reduces the anastomotic leakage rate compared with hand sewing. End-to-side stapling increases the risk of anastomotic strictures, but side-to-side stapling decreases the risk. PMID:25493038
Jeong, Hyeonseok; Ryu, Kil O; Lim, Jiyong; Kim, Hyun Tae; Yu, Hye Mi; Yoon, Jihoon; Lee, Ju-Young; Kim, Hyoung Rae; Choi, Young Gil
2017-01-01
Purpose Circular stapled hemorrhoidopexy (CSH) is widely used to treat patients with grades III–IV hemorrhoids because of less pain and short hospital stay. However, this procedure is associated with some complications, such as urge to defecate, anal stenosis, staple line dehiscence, abscess and sepsis. To avoid these complications, surgeons perform a partial stapled hemorrhoidopexy (PSH). The aim of this study is to present our early experience with the PSH. Methods We retrospectively reviewed the medical records of 58 patients with hemorrhoids who were treated with a PSH at Busan Hang-Un Hospital from January 2016 to June 2016. A specially designed tri-window anoscope was used, and a purse string suture was made at the mucosae of the protruding hemorrhoids through the window of the anoscope. The hemorrhoidopexy was done by using a circular stapler. Results Of the 58 patients included in this study, 34 were male and 24 were female patients (mean age, 50.4 years). The mean operation time was 12.4 minutes, and the mean postoperative hospital stay was 3.8 days. Three patients experienced bleeding (5.1%) 5 urinary retention (8.6%) and 5 skin tags (8.6%). Urge to defecate, tenesmus, abscess, rectovaginal fistula, anal stricture, incontinence, and recurrence did not occur. Conclusion PSH is a minimally invasive, feasible, and safe technique for treating patients with grades III–IV hemorrhoids. A PSH, instead of a CSH, can be used to treat certain patients with hemorrhoids. PMID:28289661
Stroh, Christine; Köckerling, Ferdinand; Volker, Lange; Frank, Benedix; Stefanie, Wolff; Christian, Knoll; Christiane, Bruns; Thomas, Manger
2016-05-01
Laparoscopic sleeve gastrectomy (SG) is an upcoming procedure in bariatric surgery and is currently performed worldwide. Staple line leakage, as the most frequent and most feared complication, is still a major concern. Since 2005 data from patients undergoing bariatric procedures in Germany have been prospectively registered in an online database and analyzed. All patients who had undergone primary SG within a 7-year period were considered for analysis. Using the German Bariatric Surgery Registry, data from more than 11,800 SGs were collected between January 1, 2005, and December 31, 2013. Staple line leak rate decreased from 6.5% to 1.4%. Male sex, higher body mass index, concomitant sleep apnea, conversion to laparotomy, longer operation time, a combination of buttresses and oversewing, and the occurrence of intraoperative complications were associated with a significantly higher leakage rate compared with when using either buttresses or oversewing alone. On multivariable analysis, operation time and year of procedure only had a significant impact on staple line leakage rate. Owing to the growing experience a constant decrease in the leakage rate after SG has been observed. Staple line disruption may still lead to sepsis, multiorgan dysfunction, and increased mortality. The results of the current study demonstrated that there are factors that increase the risk of leakage and which would enable surgeons to define risk groups, select patients more carefully, and offer closer follow-up during the postoperative course with early recognition and adequate treatment.
NASA Technical Reports Server (NTRS)
Yang, Song; Olson, William S.; Wang, Jian-Jian; Bell, Thomas L.; Smith, Eric A.; Kummerow, Christian D.
2004-01-01
Rainfall rate estimates from space-borne k&ents are generally accepted as reliable by a majority of the atmospheric science commu&y. One-of the Tropical Rainfall Measuring Mission (TRh4M) facility rain rate algorithms is based upon passive microwave observations fiom the TRMM Microwave Imager (TMI). Part I of this study describes improvements in the TMI algorithm that are required to introduce cloud latent heating and drying as additional algorithm products. Here, estimates of surface rain rate, convective proportion, and latent heating are evaluated using independent ground-based estimates and satellite products. Instantaneous, OP5resolution estimates of surface rain rate over ocean fiom the improved TMI algorithm are well correlated with independent radar estimates (r approx. 0.88 over the Tropics), but bias reduction is the most significant improvement over forerunning algorithms. The bias reduction is attributed to the greater breadth of cloud-resolving model simulations that support the improved algorithm, and the more consistent and specific convective/stratiform rain separation method utilized. The bias of monthly, 2.5 deg. -resolution estimates is similarly reduced, with comparable correlations to radar estimates. Although the amount of independent latent heating data are limited, TMI estimated latent heating profiles compare favorably with instantaneous estimates based upon dual-Doppler radar observations, and time series of surface rain rate and heating profiles are generally consistent with those derived from rawinsonde analyses. Still, some biases in profile shape are evident, and these may be resolved with: (a) additional contextual information brought to the estimation problem, and/or; (b) physically-consistent and representative databases supporting the algorithm. A model of the random error in instantaneous, 0.5 deg-resolution rain rate estimates appears to be consistent with the levels of error determined from TMI comparisons to collocated radar. Error model modifications for non-raining situations will be required, however. Sampling error appears to represent only a fraction of the total error in monthly, 2S0-resolution TMI estimates; the remaining error is attributed to physical inconsistency or non-representativeness of cloud-resolving model simulated profiles supporting the algorithm.
Sugerman, H J; Newsome, H H; Decosta, G; Zfass, A M
1991-01-01
Between March 1989 and August 1990, we performed 21 stapled J pouch ileonal procedures (20 ulcerative colitis [UC], 1 familial polyposis [FP]) without an ileostomy in 19, of whom 13 were taking prednisone and eight underwent semi-emergent surgery for uncontrollable bleeding. During the same time, an additional four patients required a standard ileonal procedure. The results of anal manometry and clinical function were compared to 25 patients who had previously undergone mucosal stripping and a sutured J pouch ileoanal anastomoses with a temporary diverting ileostomy between October 1982 and August 1990. During this same time period, an additional 19 patients underwent an anti-peristaltic reversed J pouch and 18 an S pouch, for a total of 83 ileoanal procedures. The reversed J pouch had a lower stool frequency than a standard J pouch but had an unacceptable incidence of complications and problems with pouch emptying. The S pouch had a stool frequency similar to the standard J pouch but provided greater length in patients with a short mesentery. Stapled J pouch ileoanal patients had a better (p less than 0.02) maximum and sphincter resting pressure (46 +/- 11 versus 34 +/- 12 mmHg), fewer (p less than 0.05) night-time accidents (22% versus 68%), daytime (17% versus 55%) or night-time (28 versus 61%) spotting, or use of a protective pad at night (11% versus 42%) than nonstapled J pouch ileoanal patients. Stool frequency was similar in the two groups. All but one UC patient had residual disease at the anastomosis. Anal mucosa between the dentate line and stapled anastomosis was 1.8 +/- 1.3 cm (range, 0 to 3.5 cm). Complications in the nonstapled J pouch group included 4 pouches excised (2 for complications, 2 for excessive stool frequency), 1 pelvic abscess, 2 stenosis requiring dilation under anesthesia, 1 enterocutaneous fistula after ileostomy closure, 1 ileostomy site hernia, and 2 small bowel obstructions. Of the 65 patients who underwent ileostomy closure in the entire series, 8 (12%) developed a complication requiring surgical intervention. Complications in the stapled group included 1 anastomotic leak, 1 pouch leak, and 1 pelvic abscess. Patients were managed successfully with drainage (all 3) and diverting ileostomy (1). One patient developed stenosis requiring dilation under anesthesia. The stapled J pouch ileoanal anastomosis is a simpler, safer procedure with less tension than a standard handsewn J pouch but leaves a very small cuff of residual disease. It provides significantly better stool control and may obviate the need for an ileostomy with its complications. PMID:2039292
Parameter expansion for estimation of reduced rank covariance matrices (Open Access publication)
Meyer, Karin
2008-01-01
Parameter expanded and standard expectation maximisation algorithms are described for reduced rank estimation of covariance matrices by restricted maximum likelihood, fitting the leading principal components only. Convergence behaviour of these algorithms is examined for several examples and contrasted to that of the average information algorithm, and implications for practical analyses are discussed. It is shown that expectation maximisation type algorithms are readily adapted to reduced rank estimation and converge reliably. However, as is well known for the full rank case, the convergence is linear and thus slow. Hence, these algorithms are most useful in combination with the quadratically convergent average information algorithm, in particular in the initial stages of an iterative solution scheme. PMID:18096112
Schmidt, Taly Gilat; Wang, Adam S; Coradi, Thomas; Haas, Benjamin; Star-Lack, Josh
2016-10-01
The overall goal of this work is to develop a rapid, accurate, and automated software tool to estimate patient-specific organ doses from computed tomography (CT) scans using simulations to generate dose maps combined with automated segmentation algorithms. This work quantified the accuracy of organ dose estimates obtained by an automated segmentation algorithm. We hypothesized that the autosegmentation algorithm is sufficiently accurate to provide organ dose estimates, since small errors delineating organ boundaries will have minimal effect when computing mean organ dose. A leave-one-out validation study of the automated algorithm was performed with 20 head-neck CT scans expertly segmented into nine regions. Mean organ doses of the automatically and expertly segmented regions were computed from Monte Carlo-generated dose maps and compared. The automated segmentation algorithm estimated the mean organ dose to be within 10% of the expert segmentation for regions other than the spinal canal, with the median error for each organ region below 2%. In the spinal canal region, the median error was [Formula: see text], with a maximum absolute error of 28% for the single-atlas approach and 11% for the multiatlas approach. The results demonstrate that the automated segmentation algorithm can provide accurate organ dose estimates despite some segmentation errors.
Schmidt, Taly Gilat; Wang, Adam S.; Coradi, Thomas; Haas, Benjamin; Star-Lack, Josh
2016-01-01
Abstract. The overall goal of this work is to develop a rapid, accurate, and automated software tool to estimate patient-specific organ doses from computed tomography (CT) scans using simulations to generate dose maps combined with automated segmentation algorithms. This work quantified the accuracy of organ dose estimates obtained by an automated segmentation algorithm. We hypothesized that the autosegmentation algorithm is sufficiently accurate to provide organ dose estimates, since small errors delineating organ boundaries will have minimal effect when computing mean organ dose. A leave-one-out validation study of the automated algorithm was performed with 20 head-neck CT scans expertly segmented into nine regions. Mean organ doses of the automatically and expertly segmented regions were computed from Monte Carlo-generated dose maps and compared. The automated segmentation algorithm estimated the mean organ dose to be within 10% of the expert segmentation for regions other than the spinal canal, with the median error for each organ region below 2%. In the spinal canal region, the median error was −7%, with a maximum absolute error of 28% for the single-atlas approach and 11% for the multiatlas approach. The results demonstrate that the automated segmentation algorithm can provide accurate organ dose estimates despite some segmentation errors. PMID:27921070
Error Estimation for the Linearized Auto-Localization Algorithm
Guevara, Jorge; Jiménez, Antonio R.; Prieto, Jose Carlos; Seco, Fernando
2012-01-01
The Linearized Auto-Localization (LAL) algorithm estimates the position of beacon nodes in Local Positioning Systems (LPSs), using only the distance measurements to a mobile node whose position is also unknown. The LAL algorithm calculates the inter-beacon distances, used for the estimation of the beacons’ positions, from the linearized trilateration equations. In this paper we propose a method to estimate the propagation of the errors of the inter-beacon distances obtained with the LAL algorithm, based on a first order Taylor approximation of the equations. Since the method depends on such approximation, a confidence parameter τ is defined to measure the reliability of the estimated error. Field evaluations showed that by applying this information to an improved weighted-based auto-localization algorithm (WLAL), the standard deviation of the inter-beacon distances can be improved by more than 30% on average with respect to the original LAL method. PMID:22736965
Maneuver Algorithm for Bearings-Only Target Tracking with Acceleration and Field of View Constraints
NASA Astrophysics Data System (ADS)
Roh, Heekun; Shim, Sang-Wook; Tahk, Min-Jea
2018-05-01
This paper proposes a maneuver algorithm for the agent performing target tracking with bearing angle information only. The goal of the agent is to estimate the target position and velocity based only on the bearing angle data. The methods of bearings-only target state estimation are outlined. The nature of bearings-only target tracking problem is then addressed. Based on the insight from above-mentioned properties, the maneuver algorithm for the agent is suggested. The proposed algorithm is composed of a nonlinear, hysteresis guidance law and the estimation accuracy assessment criteria based on the theory of Cramer-Rao bound. The proposed guidance law generates lateral acceleration command based on current field of view angle. The accuracy criteria supply the expected estimation variance, which acts as a terminal criterion for the proposed algorithm. The aforementioned algorithm is verified with a two-dimensional simulation.
Estimating Position of Mobile Robots From Omnidirectional Vision Using an Adaptive Algorithm.
Li, Luyang; Liu, Yun-Hui; Wang, Kai; Fang, Mu
2015-08-01
This paper presents a novel and simple adaptive algorithm for estimating the position of a mobile robot with high accuracy in an unknown and unstructured environment by fusing images of an omnidirectional vision system with measurements of odometry and inertial sensors. Based on a new derivation where the omnidirectional projection can be linearly parameterized by the positions of the robot and natural feature points, we propose a novel adaptive algorithm, which is similar to the Slotine-Li algorithm in model-based adaptive control, to estimate the robot's position by using the tracked feature points in image sequence, the robot's velocity, and orientation angles measured by odometry and inertial sensors. It is proved that the adaptive algorithm leads to global exponential convergence of the position estimation errors to zero. Simulations and real-world experiments are performed to demonstrate the performance of the proposed algorithm.
On the estimation algorithm used in adaptive performance optimization of turbofan engines
NASA Technical Reports Server (NTRS)
Espana, Martin D.; Gilyard, Glenn B.
1993-01-01
The performance seeking control algorithm is designed to continuously optimize the performance of propulsion systems. The performance seeking control algorithm uses a nominal model of the propulsion system and estimates, in flight, the engine deviation parameters characterizing the engine deviations with respect to nominal conditions. In practice, because of measurement biases and/or model uncertainties, the estimated engine deviation parameters may not reflect the engine's actual off-nominal condition. This factor has a necessary impact on the overall performance seeking control scheme exacerbated by the open-loop character of the algorithm. The effects produced by unknown measurement biases over the estimation algorithm are evaluated. This evaluation allows for identification of the most critical measurements for application of the performance seeking control algorithm to an F100 engine. An equivalence relation between the biases and engine deviation parameters stems from an observability study; therefore, it is undecided whether the estimated engine deviation parameters represent the actual engine deviation or whether they simply reflect the measurement biases. A new algorithm, based on the engine's (steady-state) optimization model, is proposed and tested with flight data. When compared with previous Kalman filter schemes, based on local engine dynamic models, the new algorithm is easier to design and tune and it reduces the computational burden of the onboard computer.
Estimating the chance of success in IVF treatment using a ranking algorithm.
Güvenir, H Altay; Misirli, Gizem; Dilbaz, Serdar; Ozdegirmenci, Ozlem; Demir, Berfu; Dilbaz, Berna
2015-09-01
In medicine, estimating the chance of success for treatment is important in deciding whether to begin the treatment or not. This paper focuses on the domain of in vitro fertilization (IVF), where estimating the outcome of a treatment is very crucial in the decision to proceed with treatment for both the clinicians and the infertile couples. IVF treatment is a stressful and costly process. It is very stressful for couples who want to have a baby. If an initial evaluation indicates a low pregnancy rate, decision of the couple may change not to start the IVF treatment. The aim of this study is twofold, firstly, to develop a technique that can be used to estimate the chance of success for a couple who wants to have a baby and secondly, to determine the attributes and their particular values affecting the outcome in IVF treatment. We propose a new technique, called success estimation using a ranking algorithm (SERA), for estimating the success of a treatment using a ranking-based algorithm. The particular ranking algorithm used here is RIMARC. The performance of the new algorithm is compared with two well-known algorithms that assign class probabilities to query instances. The algorithms used in the comparison are Naïve Bayes Classifier and Random Forest. The comparison is done in terms of area under the ROC curve, accuracy and execution time, using tenfold stratified cross-validation. The results indicate that the proposed SERA algorithm has a potential to be used successfully to estimate the probability of success in medical treatment.
Quantum algorithms for Gibbs sampling and hitting-time estimation
Chowdhury, Anirban Narayan; Somma, Rolando D.
2017-02-01
In this paper, we present quantum algorithms for solving two problems regarding stochastic processes. The first algorithm prepares the thermal Gibbs state of a quantum system and runs in time almost linear in √Nβ/Ζ and polynomial in log(1/ϵ), where N is the Hilbert space dimension, β is the inverse temperature, Ζ is the partition function, and ϵ is the desired precision of the output state. Our quantum algorithm exponentially improves the dependence on 1/ϵ and quadratically improves the dependence on β of known quantum algorithms for this problem. The second algorithm estimates the hitting time of a Markov chain. Formore » a sparse stochastic matrix Ρ, it runs in time almost linear in 1/(ϵΔ 3/2), where ϵ is the absolute precision in the estimation and Δ is a parameter determined by Ρ, and whose inverse is an upper bound of the hitting time. Our quantum algorithm quadratically improves the dependence on 1/ϵ and 1/Δ of the analog classical algorithm for hitting-time estimation. Finally, both algorithms use tools recently developed in the context of Hamiltonian simulation, spectral gap amplification, and solving linear systems of equations.« less
Diagnosis and treatment of haemorrhoids.
Buntzen, Steen; Christensen, Peter; Khalid, Ali; Ljungmann, Ken; Lindholt, Jan; Lundby, Lilli; Walker, Line Rossell; Raahave, Dennis; Qvist, Niels
2013-12-01
These guidelines provide a review of diagnosis, conservative and surgical treatment of haemorrhoids with primary focus on the surgical treatment. In symptomatic hemorrhoids it is recommended, that conservative treatment is used as basic treatment regardless of grading. The vast majority of grade II haemorrhoids are treated conservatively, but surgery may be considered in a few cases with pronounced symptoms. In these cases chirurgia minor, Doppler guided dearterilization procedures or stapled haemorrhoidopexy are recommended. In grade III and IV Doppler guided dearterilization procedures, stapled haemorrhoidopexy (Grade III) or conventional Milligan Morgan haemorrhoidectomy are recommended.
Bi, Sheng; Zeng, Xiao; Tang, Xin; Qin, Shujia; Lai, King Wai Chiu
2016-01-01
Compressive sensing (CS) theory has opened up new paths for the development of signal processing applications. Based on this theory, a novel single pixel camera architecture has been introduced to overcome the current limitations and challenges of traditional focal plane arrays. However, video quality based on this method is limited by existing acquisition and recovery methods, and the method also suffers from being time-consuming. In this paper, a multi-frame motion estimation algorithm is proposed in CS video to enhance the video quality. The proposed algorithm uses multiple frames to implement motion estimation. Experimental results show that using multi-frame motion estimation can improve the quality of recovered videos. To further reduce the motion estimation time, a block match algorithm is used to process motion estimation. Experiments demonstrate that using the block match algorithm can reduce motion estimation time by 30%. PMID:26950127
An Attitude Filtering and Magnetometer Calibration Approach for Nanosatellites
NASA Astrophysics Data System (ADS)
Söken, Halil Ersin
2018-04-01
We propose an attitude filtering and magnetometer calibration approach for nanosatellites. Measurements from magnetometers, Sun sensor and gyros are used in the filtering algorithm to estimate the attitude of the satellite together with the bias terms for the gyros and magnetometers. In the traditional approach for the attitude filtering, the attitude sensor measurements are used in the filter with a nonlinear vector measurement model. In the proposed algorithm, the TRIAD algorithm is used in conjunction with the unscented Kalman filter (UKF) to form the nontraditional attitude filter. First the vector measurements from the magnetometer and Sun sensor are processed with the TRIAD algorithm to obtain a coarse attitude estimate for the spacecraft. In the second phase the estimated coarse attitude is used as quaternion measurements for the UKF. The UKF estimates the fine attitude, and the gyro and magnetometer biases. We evaluate the algorithm for a hypothetical nanosatellite by numerical simulations. The results show that the attitude of the satellite can be estimated with an accuracy better than 0.5{°} and the computational load decreases more than 25% compared to a traditional UKF algorithm. We discuss the algorithm's performance in case of a time-variance in the magnetometer errors.
Multiuser TOA Estimation Algorithm in DS-CDMA Sparse Channel for Radiolocation
NASA Astrophysics Data System (ADS)
Kim, Sunwoo
This letter considers multiuser time delay estimation in a sparse channel environment for radiolocation. The generalized successive interference cancellation (GSIC) algorithm is used to eliminate the multiple access interference (MAI). To adapt GSIC to sparse channels the alternating maximization (AM) algorithm is considered, and the continuous time delay of each path is estimated without requiring a priori known data sequences.
Parameter estimation for chaotic systems using improved bird swarm algorithm
NASA Astrophysics Data System (ADS)
Xu, Chuangbiao; Yang, Renhuan
2017-12-01
Parameter estimation of chaotic systems is an important problem in nonlinear science and has aroused increasing interest of many research fields, which can be basically reduced to a multidimensional optimization problem. In this paper, an improved boundary bird swarm algorithm is used to estimate the parameters of chaotic systems. This algorithm can combine the good global convergence and robustness of the bird swarm algorithm and the exploitation capability of improved boundary learning strategy. Experiments are conducted on the Lorenz system and the coupling motor system. Numerical simulation results reveal the effectiveness and with desirable performance of IBBSA for parameter estimation of chaotic systems.
A Space-Time Signal Decomposition Algorithm for Downlink MIMO DS-CDMA Receivers
NASA Astrophysics Data System (ADS)
Wang, Yung-Yi; Fang, Wen-Hsien; Chen, Jiunn-Tsair
We propose a dimension reduction algorithm for the receiver of the downlink of direct-sequence code-division multiple access (DS-CDMA) systems in which both the transmitters and the receivers employ antenna arrays of multiple elements. To estimate the high order channel parameters, we develop a layered architecture using dimension-reduced parameter estimation algorithms to estimate the frequency-selective multipath channels. In the proposed architecture, to exploit the space-time geometric characteristics of multipath channels, spatial beamformers and constrained (or unconstrained) temporal filters are adopted for clustered-multipath grouping and path isolation. In conjunction with the multiple access interference (MAI) suppression techniques, the proposed architecture jointly estimates the direction of arrivals, propagation delays, and fading amplitudes of the downlink fading multipaths. With the outputs of the proposed architecture, the signals of interest can then be naturally detected by using path-wise maximum ratio combining. Compared to the traditional techniques, such as the Joint-Angle-and-Delay-Estimation (JADE) algorithm for DOA-delay joint estimation and the space-time minimum mean square error (ST-MMSE) algorithm for signal detection, computer simulations show that the proposed algorithm substantially mitigate the computational complexity at the expense of only slight performance degradation.
Jiang, Lijun; Feng, Zhaozhong; Dai, Lulu; Shang, Bo; Paoletti, Elena
2018-02-01
The sensitivity of Chinese soybean cultivars to ambient ozone (O 3 ) in the field is unknown, although soybean is a major staple food in China. Using ethylenediurea (EDU) as an O 3 protectant, we tested the gas exchange, pigments, antioxidants and biomass of 19 cultivars exposed to 28ppm·hr AOT40 (accumulated O 3 over an hourly concentration threshold of 40ppb) over the growing season at a field site in China. By comparing the average biomass with and without EDU, we estimated the cultivar-specific sensitivity to O 3 and ranked the cultivars from very tolerant (<10% change) to highly sensitive (>45% change), which helps in choosing the best-suited cultivars for local cultivation. Higher lipid peroxidation and activity of the ascorbate peroxidase enzyme were major responses to O 3 damage, which eventually translated into lower biomass production. The constitutional level of total ascorbate in the leaves was the most important parameter explaining O 3 sensitivity among these cultivars. Surprisingly, the role of stomatal conductance was insignificant. These results will guide future breeding efforts towards more O 3 -tolerant cultivars in China, while strategies for implementing control measures of regional O 3 pollution are being implemented. Overall, these results suggest that present ambient O 3 pollution is a serious concern for soybean in China, which highlights the urgent need for policy-making actions to protect this critical staple food. Copyright © 2017. Published by Elsevier B.V.
USDA-ARS?s Scientific Manuscript database
Bio-optical algorithms have been applied to monitor water quality in surface water systems. Empirical algorithms, such as Ritchie (2008), Gons (2008), and Gilerson (2010), have been applied to estimate the chlorophyll-a (chl-a) concentrations. However, the performance of each algorithm severely degr...
A Parametric k-Means Algorithm
Tarpey, Thaddeus
2007-01-01
Summary The k points that optimally represent a distribution (usually in terms of a squared error loss) are called the k principal points. This paper presents a computationally intensive method that automatically determines the principal points of a parametric distribution. Cluster means from the k-means algorithm are nonparametric estimators of principal points. A parametric k-means approach is introduced for estimating principal points by running the k-means algorithm on a very large simulated data set from a distribution whose parameters are estimated using maximum likelihood. Theoretical and simulation results are presented comparing the parametric k-means algorithm to the usual k-means algorithm and an example on determining sizes of gas masks is used to illustrate the parametric k-means algorithm. PMID:17917692
Predicting Loss-of-Control Boundaries Toward a Piloting Aid
NASA Technical Reports Server (NTRS)
Barlow, Jonathan; Stepanyan, Vahram; Krishnakumar, Kalmanje
2012-01-01
This work presents an approach to predicting loss-of-control with the goal of providing the pilot a decision aid focused on maintaining the pilot's control action within predicted loss-of-control boundaries. The predictive architecture combines quantitative loss-of-control boundaries, a data-based predictive control boundary estimation algorithm and an adaptive prediction method to estimate Markov model parameters in real-time. The data-based loss-of-control boundary estimation algorithm estimates the boundary of a safe set of control inputs that will keep the aircraft within the loss-of-control boundaries for a specified time horizon. The adaptive prediction model generates estimates of the system Markov Parameters, which are used by the data-based loss-of-control boundary estimation algorithm. The combined algorithm is applied to a nonlinear generic transport aircraft to illustrate the features of the architecture.
Pitch-Learning Algorithm For Speech Encoders
NASA Technical Reports Server (NTRS)
Bhaskar, B. R. Udaya
1988-01-01
Adaptive algorithm detects and corrects errors in sequence of estimates of pitch period of speech. Algorithm operates in conjunction with techniques used to estimate pitch period. Used in such parametric and hybrid speech coders as linear predictive coders and adaptive predictive coders.
A New Adaptive H-Infinity Filtering Algorithm for the GPS/INS Integrated Navigation
Jiang, Chen; Zhang, Shu-Bi; Zhang, Qiu-Zhao
2016-01-01
The Kalman filter is an optimal estimator with numerous applications in technology, especially in systems with Gaussian distributed noise. Moreover, the adaptive Kalman filtering algorithms, based on the Kalman filter, can control the influence of dynamic model errors. In contrast to the adaptive Kalman filtering algorithms, the H-infinity filter is able to address the interference of the stochastic model by minimization of the worst-case estimation error. In this paper, a novel adaptive H-infinity filtering algorithm, which integrates the adaptive Kalman filter and the H-infinity filter in order to perform a comprehensive filtering algorithm, is presented. In the proposed algorithm, a robust estimation method is employed to control the influence of outliers. In order to verify the proposed algorithm, experiments with real data of the Global Positioning System (GPS) and Inertial Navigation System (INS) integrated navigation, were conducted. The experimental results have shown that the proposed algorithm has multiple advantages compared to the other filtering algorithms. PMID:27999361
A New Adaptive H-Infinity Filtering Algorithm for the GPS/INS Integrated Navigation.
Jiang, Chen; Zhang, Shu-Bi; Zhang, Qiu-Zhao
2016-12-19
The Kalman filter is an optimal estimator with numerous applications in technology, especially in systems with Gaussian distributed noise. Moreover, the adaptive Kalman filtering algorithms, based on the Kalman filter, can control the influence of dynamic model errors. In contrast to the adaptive Kalman filtering algorithms, the H-infinity filter is able to address the interference of the stochastic model by minimization of the worst-case estimation error. In this paper, a novel adaptive H-infinity filtering algorithm, which integrates the adaptive Kalman filter and the H-infinity filter in order to perform a comprehensive filtering algorithm, is presented. In the proposed algorithm, a robust estimation method is employed to control the influence of outliers. In order to verify the proposed algorithm, experiments with real data of the Global Positioning System (GPS) and Inertial Navigation System (INS) integrated navigation, were conducted. The experimental results have shown that the proposed algorithm has multiple advantages compared to the other filtering algorithms.
Birkegård, Anna Camilla; Andersen, Vibe Dalhoff; Halasa, Tariq; Jensen, Vibeke Frøkjær; Toft, Nils; Vigre, Håkan
2017-10-01
Accurate and detailed data on antimicrobial exposure in pig production are essential when studying the association between antimicrobial exposure and antimicrobial resistance. Due to difficulties in obtaining primary data on antimicrobial exposure in a large number of farms, there is a need for a robust and valid method to estimate the exposure using register data. An approach that estimates the antimicrobial exposure in every rearing period during the lifetime of a pig using register data was developed into a computational algorithm. In this approach data from national registers on antimicrobial purchases, movements of pigs and farm demographics registered at farm level are used. The algorithm traces batches of pigs retrospectively from slaughter to the farm(s) that housed the pigs during their finisher, weaner, and piglet period. Subsequently, the algorithm estimates the antimicrobial exposure as the number of Animal Defined Daily Doses for treatment of one kg pig in each of the rearing periods. Thus, the antimicrobial purchase data at farm level are translated into antimicrobial exposure estimates at batch level. A batch of pigs is defined here as pigs sent to slaughter at the same day from the same farm. In this study we present, validate, and optimise a computational algorithm that calculate the lifetime exposure of antimicrobials for slaughter pigs. The algorithm was evaluated by comparing the computed estimates to data on antimicrobial usage from farm records in 15 farm units. We found a good positive correlation between the two estimates. The algorithm was run for Danish slaughter pigs sent to slaughter in January to March 2015 from farms with more than 200 finishers to estimate the proportion of farms that it was applicable for. In the final process, the algorithm was successfully run for batches of pigs originating from 3026 farms with finisher units (77% of the initial population). This number can be increased if more accurate register data can be obtained. The algorithm provides a systematic and repeatable approach to estimating the antimicrobial exposure throughout the rearing period, independent of rearing site for finisher batches, as a lifetime exposure measurement. Copyright © 2017 Elsevier B.V. All rights reserved.
An adaptive displacement estimation algorithm for improved reconstruction of thermal strain.
Ding, Xuan; Dutta, Debaditya; Mahmoud, Ahmed M; Tillman, Bryan; Leers, Steven A; Kim, Kang
2015-01-01
Thermal strain imaging (TSI) can be used to differentiate between lipid and water-based tissues in atherosclerotic arteries. However, detecting small lipid pools in vivo requires accurate and robust displacement estimation over a wide range of displacement magnitudes. Phase-shift estimators such as Loupas' estimator and time-shift estimators such as normalized cross-correlation (NXcorr) are commonly used to track tissue displacements. However, Loupas' estimator is limited by phase-wrapping and NXcorr performs poorly when the SNR is low. In this paper, we present an adaptive displacement estimation algorithm that combines both Loupas' estimator and NXcorr. We evaluated this algorithm using computer simulations and an ex vivo human tissue sample. Using 1-D simulation studies, we showed that when the displacement magnitude induced by thermal strain was >λ/8 and the electronic system SNR was >25.5 dB, the NXcorr displacement estimate was less biased than the estimate found using Loupas' estimator. On the other hand, when the displacement magnitude was ≤λ/4 and the electronic system SNR was ≤25.5 dB, Loupas' estimator had less variance than NXcorr. We used these findings to design an adaptive displacement estimation algorithm. Computer simulations of TSI showed that the adaptive displacement estimator was less biased than either Loupas' estimator or NXcorr. Strain reconstructed from the adaptive displacement estimates improved the strain SNR by 43.7 to 350% and the spatial accuracy by 1.2 to 23.0% (P < 0.001). An ex vivo human tissue study provided results that were comparable to computer simulations. The results of this study showed that a novel displacement estimation algorithm, which combines two different displacement estimators, yielded improved displacement estimation and resulted in improved strain reconstruction.
An Adaptive Displacement Estimation Algorithm for Improved Reconstruction of Thermal Strain
Ding, Xuan; Dutta, Debaditya; Mahmoud, Ahmed M.; Tillman, Bryan; Leers, Steven A.; Kim, Kang
2014-01-01
Thermal strain imaging (TSI) can be used to differentiate between lipid and water-based tissues in atherosclerotic arteries. However, detecting small lipid pools in vivo requires accurate and robust displacement estimation over a wide range of displacement magnitudes. Phase-shift estimators such as Loupas’ estimator and time-shift estimators like normalized cross-correlation (NXcorr) are commonly used to track tissue displacements. However, Loupas’ estimator is limited by phase-wrapping and NXcorr performs poorly when the signal-to-noise ratio (SNR) is low. In this paper, we present an adaptive displacement estimation algorithm that combines both Loupas’ estimator and NXcorr. We evaluated this algorithm using computer simulations and an ex-vivo human tissue sample. Using 1-D simulation studies, we showed that when the displacement magnitude induced by thermal strain was >λ/8 and the electronic system SNR was >25.5 dB, the NXcorr displacement estimate was less biased than the estimate found using Loupas’ estimator. On the other hand, when the displacement magnitude was ≤λ/4 and the electronic system SNR was ≤25.5 dB, Loupas’ estimator had less variance than NXcorr. We used these findings to design an adaptive displacement estimation algorithm. Computer simulations of TSI using Field II showed that the adaptive displacement estimator was less biased than either Loupas’ estimator or NXcorr. Strain reconstructed from the adaptive displacement estimates improved the strain SNR by 43.7–350% and the spatial accuracy by 1.2–23.0% (p < 0.001). An ex-vivo human tissue study provided results that were comparable to computer simulations. The results of this study showed that a novel displacement estimation algorithm, which combines two different displacement estimators, yielded improved displacement estimation and results in improved strain reconstruction. PMID:25585398
Zanella, Simone; Spirch, Saverio; Scarpa, Marco; Ricci, Francesco; Lumachi, Franco
2014-01-01
Circular stapled transanal hemorrhoidopexy (STH) was first introduced by A. Longo for the correction of internal mucosal prolapse and obstructed defecation and in 1998, was proposed as alternative to conventional excisional hemorrhoidectomy. More recently, stapled transanal rectal resection (STARR) has gradually gained popularity, as the Longo procedure, in the treatment of hemorrhoids. The aim of our study was to evaluate the usefulness of STARR as alternative to STH in patients with grade III (n=218, 68.1%) and IV (n=102, 31.9%) hemorrhoids. A group of 320 consecutive patients (median age=51 years; range=16-85) underwent STH (n=281) or STARR (n=39) procedure. The rate of postoperative bleeding (53.8% vs. 74.4%, p<0.01) was significantly reduced in patients who underwent STARR procedure, which required a longer (45 ± 22 vs. 26 ± 11 min, p<0.01) operative time. There were no differences between groups with regard to use of painkillers, postoperative pain intensity, short- (three months) and long-term (one and three years) residual pain, soiling, incontinence and urgency. Patients treated with the STARR procedure had lower recurrence rate of hemorrhoids and a lower incidence of prolapse, both at one year (none vs. 1.4%, p=0.593 and 2.6% vs. 5.3%, p=0.396, respectively) and at two years (none vs. 6.8%, p=0.078 and none vs. 13.2%, p=0.012, respectively). The one-year (9.0 ± 1.8 vs. 9.4 ± 0.7, p=0.171) and two-year (9.6 ± 0.8 vs. 9.1 ± 1.7, p=0.072) general satisfaction was similar but higher in STARR patients than in the STH group. In conclusion, according to our preliminary results, the STARR procedure leads to a lower incidence of complications and recurrences and should be considered for patients with grade III or IV hemorrhoids previously selected for stapled hemorrhoidectomy, as a promising alternative to STH. Copyright © 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.
Patton, Mary Lou; Mullins, Robert Fred; Smith, David; Korentager, Richard
2013-01-01
An open, prospective, randomized, pilot investigation was implemented to evaluate the pain, cost-effectiveness, ease of use, tolerance, efficacy, and safety of a soft silicone wound contact layer (Mepitel One) vs Bridal Veil and staples used on split thickness skin grafts in the treatment of deep partial or full-thickness thermal burns. Individuals aged between 18 and 70 years with deep partial or full-thickness thermal burns (1-25% TBSA) were randomized into two groups and treated for 14 days or until greater than 95% graft take was achieved, whichever occurred first. Data were obtained and analyzed on pain experienced before, during, and after dressing removal. Secondary considerations included the overall cost (direct), graft take and healing, the ease of product use, overall experience of the dressing, and adverse events. A total of 43 subjects were recruited. There were no significant differences in burn area profiles within the groups. The pain level during dressing removal was significant between the groups (P = .0118) with the removal of Mepitel One being less painful. The staff costs were lower in the group of patients treated with Mepitel One (P = .0064) as reflected in the shorter time required for dressing removal (P = .0005), with Mepitel One taking on average less than a quarter of the time to remove. There was no significant difference in healing between the two groups, with 99.0% of the Mepitel One group and 93.1% of the Bridal Veil and staples group showing greater than 95% graft take at post-op day 7 (+/-1) (P = .2373). Clinicians reported that the soft silicone dressing was easier to use, more conformable, and demonstrated better ability to stay in place, compared with the Bridal Veil and staples regime. Both treatments were well tolerated, with no serious adverse events in either treatment group. Mepitel One was at least as effective in the treatment of patients as the standard care (Bridal Veil and staples). In addition, the group of patients treated with the soft silicone dressing demonstrated decreased pain and lower costs associated with treatment.
Thoracoscopic Lobectomy in Infants and Children Utilizing a 5 mm Stapling Device.
Rothenberg, Steven
2016-12-01
Thoracoscopic lobectomy for congenital cystic lung disease has become an accepted and in many institutions the preferred technique. However, the technical challenges are many. Previous endoscopic staplers (12 mm) used commonly in adults are too large for use in infants This study evaluates the safety and efficacy of using a 5 mm stapling device to seal and divide major pulmonary structures. From July 2014 to March 2016, 26 patients of age 6 weeks to 13 months underwent thoracoscopic lobectomy for CPAM or sequestration. Weights ranged from 3.2 to 11.4 kg. There were 7 upper lobectomies, 2 middle, and 17 lower lobectomies. In each case, the 5 mm stapler (Justright Surgical; Louisville, Colorado) was the primary device for vessel and bronchial sealing and division. It is 4.8 mm in diameter with an anvil length of 25 mm and lays down four rows of staples and divides between them. A 3 mm sealing device was used for dissection and to take smaller segmental vessels as necessary. Stump lines were evaluated for bleeding or air leak in all cases. All procedures were accomplished successfully thoracoscopically. The stapler was used on the main lobar artery cases and vein in 24 cases, a large systemic sequestration vessel in 5 cases, and the bronchus in all 26. The stapler was also used to complete the minor fissure in 1 case and the major fissure in 1 case. A total of 96 staple loads were fired. Operative times ranged from 35 to 135 minutes. There was no significant bleeding of any vascular stump. In 1 case, the edge of the bronchial stump had to be reinforced, this was thought to be secondary to too much tissue being enclosed in the jaws. There were no postoperative complications. The use of a 5 mm stapling device appears to be safe and effective in thoracoscopic lobectomy in infants. It allows for safe management of major pulmonary vessels and bronchi in the confined chest of an infant through a single 5 mm port.
Chen, Chuang-Wei; Kang, Jung-Cheng; Wu, Chang-Chieh; Hsiao, Cheng-Wen; Jao, Shu-Wen
2008-03-01
Residual prolapsed piles is a problem after the stapled hemorrhoidopexy, especially in large third- or fourth-degree hemorrhoids. We have developed a method using additional traction sutures along with modified Longo's procedure to manage this problem. From January 2005 to October 2005, 30 consecutive patients with symptomatic third- or fourth-degree hemorrhoids who underwent the modified Longo's stapled hemorrhoidopexy with additional traction sutures in a single institution were collected. The demographics, postoperative pain score, surgical features, outcomes, and early and late complications were recorded. All patients were followed for a mean duration of 8.8 (range, 4-15) months. Thirty patients (17 males) with a mean age of 45 (range, 27-63) years were identified. The mean postoperative pain score on the morning of the first postoperative day was 2.8 (range, 1-4). The mean duration of operation was 30.7 (range, 25-37) min. The mean duration of hospital stay was 2 (range, 1-3) days. The mean days for patients to resume normal work was 6.7 (range, 4-9) days. No other procedure-related complications occurred in all patients. There was no early complication except for fecal urgency found in one patient during the first postoperative days. Regarding the late complications, no residual prolapsed piles, persistent anal pain, incontinence, anal stenosis, or recurrent symptoms were found. Our preliminary experiences indicated that this modified procedures truly contributed to reduce the residual internal hemorrhoids and maintained the benefits of stapled hemorrhoidopexy. Randomized trial and long-term follow-up warrant to determine possible surgical and functional outcome.
Raza, Qaisar; Nicolaou, Mary; Snijder, Marieke B; Stronks, Karien; Seidell, Jacob C
2017-08-01
To test Koctürk's model of dietary change among South-Asian Surinamese in the Netherlands. The model categorizes foods into staple, complementary and accessory foods and postulates that dietary change after migration begins with accessory foods while foods associated with ethnic identity (staple foods) change at a slower rate. Cross-sectional data from the HELIUS study. Dietary intake was assessed with an FFQ. Acculturation was based on social contacts and sense of belonging and was translated into four strategies of acculturation: assimilation, integration, separation and marginalization. Other indicators of acculturation included residence duration, age at migration and migration generation status. Amsterdam, the Netherlands. Participants of Dutch (n 1456) and South-Asian Surinamese origin (n 968). Across all acculturation strategies, South-Asian Surinamese participants reported significantly higher intakes of rice (staple food) and chicken (complementary food) and significantly lower intakes of red meat and vegetables (complementary foods) and cookies and sweets (accessory food) than Dutch participants. Men, second-generation and assimilated South-Asian Surinamese were inclined towards Dutch foods such as potato, pasta and red meat. Accessory foods like fruits showed variation across acculturation strategies. Consistent with the Koctürk model, the intake of staple foods was stable among South-Asian Surinamese irrespective of acculturation strategy while the intake of accessory foods like fruit varied. Contrary to expectations, South-Asian Surinamese showed consistently high intakes of complementary foods like chicken and fish irrespective of acculturation strategy. Public health practitioners should take into consideration the complex and dynamic nature of dietary acculturation.
Moon, Jeong-Ho; Yamamoto, Kazuyoshi; Yanagimoto, Yoshitomo; Sugimura, Keijirou; Miyata, Hiroshi; Yano, Masahiko; Sakon, Masato
2017-01-01
Intracorporeal esophagojejunostomy after laparoscopic total gastrectomy is technically difficult because this procedure should be performed in a narrow surgical field in the upper abdomen even when completely laparoscopic approaches are used. The placement of the anvil of a circular stapling device into the esophagus and connection the instrument to the anvil are extremely difficult steps in this surgery. Therefore, we developed a simple technique for intracorporeal esophagojejunostomy using hemi-double stapling technique; we named this technique the efficient purse-string stapling technique (EST). More recently, we have developed a modified EST (mEST) that utilizes a new stainless steel anvil rod instead of a plastic rod. Relative to the plastic rod, the steel rod is reusable and shorter; thus, it was easier to perform anvil placement into the esophagus with the steel rod. Anvil preparation for mEST: a stainless steel rod is attached to the shaft of the anvil, and the needle and thread are sutured to the tip of the rod. After complete insertion of the anvil into the esophageal cavity, the needle and thread are used to penetrate the anterior esophageal wall, and the esophagus is then clamped using a linear stapler just distal to the site penetrated by the thread. The linear stapler is fired, and anvil placement in the esophagus is simultaneously accomplished. After the rod is removed from the anvil, the instrument is intracorporeally connected to the anvil and then fired to complete the gastrojejunostomy. This technique is simple and facilitates intracorporeal reconstruction procedures in laparoscopic total gastrectomy. PMID:28815221
2014-01-01
Background Free jejunal interposition is a useful technique for reconstruction of the cervical esophagus. However, the distal anastomosis between the graft and the remaining thoracic esophagus or a gastric conduit can be technically challenging when located very low in the thoracic aperture. We here describe a modified technique for retrograde stapling of a jejunal graft to a failed gastric conduit using a circular stapler on a delivery system. Case presentation A 56 year-old patient had been referred for esophageal squamous cell carcinoma at 20 cm from the incisors. On day 8 after thoracoabdominal esophagectomy with gastric pull-up, an anastomotic leakage was diagnosed. A proximal-release stent was successfully placed by gastroscopy and the patient was discharged. Two weeks later, an esophagotracheal fistula occurred proximal to the esophageal stent. Cervical esophagostomy was performed with cranial closure of the gastric conduit, which was left in situ within the right hemithorax. Three months later, reconstruction was performed using a free jejunal interposition. The anvil of a circular stapler (Orvil®, Covidien) was placed transabdominally through an endoscopic rendez-vous procedure into the gastric conduit. A free jejunal graft was retrogradely stapled to the proximal end of the conduit. Microvascular anastomoses were performed subsequently. The proximal anastomosis of the conduit was completed manually after reperfusion. Conclusions This modified technique allows stapling of a jejunal interposition graft located deep in the thoracic aperture and is therefore a useful method that may help to avoid reconstruction by colonic pull-up and thoracotomy. PMID:25319372
Benedix, Frank; Benedix, Diana D; Knoll, Christian; Weiner, Rudolf; Bruns, Christiane; Manger, Thomas; Stroh, Christine
2014-10-01
Laparoscopic sleeve gastrectomy (LSG) is currently being performed with increasing frequency worldwide. It offers an excellent weight loss and resolution of comorbidities in the short term with a very low incidence of complications. However, the ever present risk of a staple line leak is still a major concern. Since 2005, data from obese patients that undergo bariatric procedures in Germany are prospectively registered in an online database and analyzed at the Institute of Quality Assurance in Surgical Medicine. For the current analysis, all patients that had undergone primary sleeve gastrectomy for morbid obesity within a 7-year period were considered. Using the GBSR, data from 5.400 LSGs were considered for analysis. Staple line leak rate decreased during the study period from 6.5 to 1.4 %. Male gender, higher BMI, concomitant sleep apnea, conversion to laparotomy, longer operation time, use of both buttresses and oversewing, and the occurrence of intraoperative complications were associated with a significantly higher leakage rate. On multivariate analysis, operation time and year of procedure only had a significant impact on staple line leak rate. The results of the current study demonstrated that there are factors that increase the risk of a leakage which would enable surgeons to define risk groups, to more carefully select patients, and to offer a closer follow-up during the postoperative course with early recognition and adequate treatment. All future efforts should be focused on a further reduction of serious complications to make the LSG a widely accepted and safer procedure.
"How I do it"--radical right colectomy with side-to-side stapled ileo-colonic anastomosis.
Hübner, M; Larson, D W; Wolff, B G
2012-08-01
Standardization of surgical technique helps to reproduce excellent clinical outcomes, especially in teaching institutions. We aim to describe in detail our established approach for oncological right colectomy. The right colon is mobilized in a five-step latero-inferior approach starting off with the terminal ileum, visualizing the duodenum and the head of pancreas. The ascending colon is dissected from the retroperitoneum, and takedown of the hepatic flexure is completed coming retrograde from the transverse colon. Transection of the remaining retroperitoneal attachments completes exposure of the duodenum and mobilization of the right colon. Ileocolic vessels are dissected out and divided close to their origin, and the mesocolon is divided. We then establish intestinal continuity by use of a side-to-side stapled technique. The arms of a linear cutting stapler are inserted via transverse incisions at the anti-mesenteric sides of the terminal ileum and the transverse colon (tenia) and fired. The enterotomy site is closed by removal of the specimen using a second transverse firing of the linear cutting stapler. An important final step is the reinforcement of the anastomotic ends and the crossing of the staple lines; an omental patch and closure of the mesenteric window are optional. The suggested standardized five-step lateral-to-medial dissection of the right colon and the three-step side-to-side stapled technique for ileo-colonic anastomosis are easy to learn and to reproduce. Careful adherence to pivotal technical details will help to obtain an optimal oncological outcome and a consistently low leak rate around 2%.
Breakfast staple types affect brain gray matter volume and cognitive function in healthy children.
Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Asano, Michiko; Asano, Kohei; Kawashima, Ryuta
2010-12-08
Childhood diet is important for brain development. Furthermore, the quality of breakfast is thought to affect the cognitive functioning of well-nourished children. To analyze the relationship among breakfast staple type, gray matter volume, and intelligence quotient (IQ) in 290 healthy children, we used magnetic resonance images and applied voxel-based morphometry. We divided subjects into rice, bread, and both groups according to their breakfast staple. We showed that the rice group had a significantly larger gray matter ratio (gray matter volume percentage divided by intracranial volume) and significantly larger regional gray matter volumes of several regions, including the left superior temporal gyrus. The bread group had significantly larger regional gray and white matter volumes of several regions, including the right frontoparietal region. The perceptual organization index (POI; IQ subcomponent) of the rice group was significantly higher than that of the bread group. All analyses were adjusted for age, gender, intracranial volume, socioeconomic status, average weekly frequency of having breakfast, and number of side dishes eaten for breakfast. Although several factors may have affected the results, one possible mechanism underlying the difference between the bread and the rice groups may be the difference in the glycemic index (GI) of these two substances; foods with a low GI are associated with less blood-glucose fluctuation than are those with a high GI. Our study suggests that breakfast staple type affects brain gray and white matter volumes and cognitive function in healthy children; therefore, a diet of optimal nutrition is important for brain maturation during childhood and adolescence.
Klop, Cornelis; Deden, Laura N; Aarts, Edo O; Janssen, Ignace M C; Pijl, Milan E J; van den Ende, Anneline; Witteman, Bart P L; de Jong, Gabie M; Aufenacker, Theo J; Slump, Cornelis H; Berends, Frits J
2018-02-05
The purposes of the study are to outline the complexity of diagnosing internal herniation after Roux-en-Y gastric bypass (RYGB) surgery and to investigate the added value of computed tomography angiography (CTA) for diagnosing internal herniation. A cadaver study was performed to investigate the manifestations of internal hernias and mesenteric vascularization. Furthermore, a prospective, ethics approved study with retrospective interpretation was conducted. Ten patients, clinically suspected for internal herniation, were prospectively included. After informed consent was obtained, these subjects underwent abdominal CT examination, including additional arterial phase CTA. All subjects underwent diagnostic laparoscopy for suspected internal herniation. The CTA was used to create a 3D reconstruction of the mesenteric arteries and surgical staples (3D CTA). The 3D CTA was interpreted, taking into account the presence and type of internal hernia that was found upon laparoscopy. Cadaveric analysis demonstrated the complexity of internal herniation. It also confirmed the expected changes in vascular structure and surgical staple arrangement in the presence of internal herniation. 3D CTA studies of the subjects with active internal hernias demonstrated remarkable differences when compared to control 3D CTA studies. The blood supply of herniated intestinal limbs in particular showed abnormal trajectories. Additionally, enteroenterostomy staple lines had migrated or altered orientation. 3D CTA is a promising technique for diagnosing active internal hernias. Our findings suggest that for diagnosing internal hernias, focus should probably shift from routine abdominal CT examination towards the 3D assessment of the mesenteric vasculature and surgical staples.
Two-pass imputation algorithm for missing value estimation in gene expression time series.
Tsiporkova, Elena; Boeva, Veselka
2007-10-01
Gene expression microarray experiments frequently generate datasets with multiple values missing. However, most of the analysis, mining, and classification methods for gene expression data require a complete matrix of gene array values. Therefore, the accurate estimation of missing values in such datasets has been recognized as an important issue, and several imputation algorithms have already been proposed to the biological community. Most of these approaches, however, are not particularly suitable for time series expression profiles. In view of this, we propose a novel imputation algorithm, which is specially suited for the estimation of missing values in gene expression time series data. The algorithm utilizes Dynamic Time Warping (DTW) distance in order to measure the similarity between time expression profiles, and subsequently selects for each gene expression profile with missing values a dedicated set of candidate profiles for estimation. Three different DTW-based imputation (DTWimpute) algorithms have been considered: position-wise, neighborhood-wise, and two-pass imputation. These have initially been prototyped in Perl, and their accuracy has been evaluated on yeast expression time series data using several different parameter settings. The experiments have shown that the two-pass algorithm consistently outperforms, in particular for datasets with a higher level of missing entries, the neighborhood-wise and the position-wise algorithms. The performance of the two-pass DTWimpute algorithm has further been benchmarked against the weighted K-Nearest Neighbors algorithm, which is widely used in the biological community; the former algorithm has appeared superior to the latter one. Motivated by these findings, indicating clearly the added value of the DTW techniques for missing value estimation in time series data, we have built an optimized C++ implementation of the two-pass DTWimpute algorithm. The software also provides for a choice between three different initial rough imputation methods.
A rate-constrained fast full-search algorithm based on block sum pyramid.
Song, Byung Cheol; Chun, Kang-Wook; Ra, Jong Beom
2005-03-01
This paper presents a fast full-search algorithm (FSA) for rate-constrained motion estimation. The proposed algorithm, which is based on the block sum pyramid frame structure, successively eliminates unnecessary search positions according to rate-constrained criterion. This algorithm provides the identical estimation performance to a conventional FSA having rate constraint, while achieving considerable reduction in computation.
Optimal Doppler centroid estimation for SAR data from a quasi-homogeneous source
NASA Technical Reports Server (NTRS)
Jin, M. Y.
1986-01-01
This correspondence briefly describes two Doppler centroid estimation (DCE) algorithms, provides a performance summary for these algorithms, and presents the experimental results. These algorithms include that of Li et al. (1985) and a newly developed one that is optimized for quasi-homogeneous sources. The performance enhancement achieved by the optimal DCE algorithm is clearly demonstrated by the experimental results.
Fat water decomposition using globally optimal surface estimation (GOOSE) algorithm.
Cui, Chen; Wu, Xiaodong; Newell, John D; Jacob, Mathews
2015-03-01
This article focuses on developing a novel noniterative fat water decomposition algorithm more robust to fat water swaps and related ambiguities. Field map estimation is reformulated as a constrained surface estimation problem to exploit the spatial smoothness of the field, thus minimizing the ambiguities in the recovery. Specifically, the differences in the field map-induced frequency shift between adjacent voxels are constrained to be in a finite range. The discretization of the above problem yields a graph optimization scheme, where each node of the graph is only connected with few other nodes. Thanks to the low graph connectivity, the problem is solved efficiently using a noniterative graph cut algorithm. The global minimum of the constrained optimization problem is guaranteed. The performance of the algorithm is compared with that of state-of-the-art schemes. Quantitative comparisons are also made against reference data. The proposed algorithm is observed to yield more robust fat water estimates with fewer fat water swaps and better quantitative results than other state-of-the-art algorithms in a range of challenging applications. The proposed algorithm is capable of considerably reducing the swaps in challenging fat water decomposition problems. The experiments demonstrate the benefit of using explicit smoothness constraints in field map estimation and solving the problem using a globally convergent graph-cut optimization algorithm. © 2014 Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Park, Sang-Gon; Jeong, Dong-Seok
2000-12-01
In this paper, we propose a fast adaptive diamond search algorithm (FADS) for block matching motion estimation. Many fast motion estimation algorithms reduce the computational complexity by the UESA (Unimodal Error Surface Assumption) where the matching error monotonically increases as the search moves away from the global minimum point. Recently, many fast BMAs (Block Matching Algorithms) make use of the fact that global minimum points in real world video sequences are centered at the position of zero motion. But these BMAs, especially in large motion, are easily trapped into the local minima and result in poor matching accuracy. So, we propose a new motion estimation algorithm using the spatial correlation among the neighboring blocks. We move the search origin according to the motion vectors of the spatially neighboring blocks and their MAEs (Mean Absolute Errors). The computer simulation shows that the proposed algorithm has almost the same computational complexity with DS (Diamond Search), but enhances PSNR. Moreover, the proposed algorithm gives almost the same PSNR as that of FS (Full Search), even for the large motion with half the computational load.
NASA Astrophysics Data System (ADS)
Rashid, Ahmar; Khambampati, Anil Kumar; Kim, Bong Seok; Liu, Dong; Kim, Sin; Kim, Kyung Youn
EIT image reconstruction is an ill-posed problem, the spatial resolution of the estimated conductivity distribution is usually poor and the external voltage measurements are subject to variable noise. Therefore, EIT conductivity estimation cannot be used in the raw form to correctly estimate the shape and size of complex shaped regional anomalies. An efficient algorithm employing a shape based estimation scheme is needed. The performance of traditional inverse algorithms, such as the Newton Raphson method, used for this purpose is below par and depends upon the initial guess and the gradient of the cost functional. This paper presents the application of differential evolution (DE) algorithm to estimate complex shaped region boundaries, expressed as coefficients of truncated Fourier series, using EIT. DE is a simple yet powerful population-based, heuristic algorithm with the desired features to solve global optimization problems under realistic conditions. The performance of the algorithm has been tested through numerical simulations, comparing its results with that of the traditional modified Newton Raphson (mNR) method.
Inertial sensor-based smoother for gait analysis.
Suh, Young Soo
2014-12-17
An off-line smoother algorithm is proposed to estimate foot motion using an inertial sensor unit (three-axis gyroscopes and accelerometers) attached to a shoe. The smoother gives more accurate foot motion estimation than filter-based algorithms by using all of the sensor data instead of using the current sensor data. The algorithm consists of two parts. In the first part, a Kalman filter is used to obtain initial foot motion estimation. In the second part, the error in the initial estimation is compensated using a smoother, where the problem is formulated in the quadratic optimization problem. An efficient solution of the quadratic optimization problem is given using the sparse structure. Through experiments, it is shown that the proposed algorithm can estimate foot motion more accurately than a filter-based algorithm with reasonable computation time. In particular, there is significant improvement in the foot motion estimation when the foot is moving off the floor: the z-axis position error squared sum (total time: 3.47 s) when the foot is in the air is 0.0807 m2 (Kalman filter) and 0.0020 m2 (the proposed smoother).
An Improved Aerial Target Localization Method with a Single Vector Sensor
Zhao, Anbang; Bi, Xuejie; Hui, Juan; Zeng, Caigao; Ma, Lin
2017-01-01
This paper focuses on the problems encountered in the actual data processing with the use of the existing aerial target localization methods, analyzes the causes of the problems, and proposes an improved algorithm. Through the processing of the sea experiment data, it is found that the existing algorithms have higher requirements for the accuracy of the angle estimation. The improved algorithm reduces the requirements of the angle estimation accuracy and obtains the robust estimation results. The closest distance matching estimation algorithm and the horizontal distance estimation compensation algorithm are proposed. The smoothing effect of the data after being post-processed by using the forward and backward two-direction double-filtering method has been improved, thus the initial stage data can be filtered, so that the filtering results retain more useful information. In this paper, the aerial target height measurement methods are studied, the estimation results of the aerial target are given, so as to realize the three-dimensional localization of the aerial target and increase the understanding of the underwater platform to the aerial target, so that the underwater platform has better mobility and concealment. PMID:29135956
DOA estimation of noncircular signals for coprime linear array via locally reduced-dimensional Capon
NASA Astrophysics Data System (ADS)
Zhai, Hui; Zhang, Xiaofei; Zheng, Wang
2018-05-01
We investigate the issue of direction of arrival (DOA) estimation of noncircular signals for coprime linear array (CLA). The noncircular property enhances the degree of freedom and improves angle estimation performance, but it leads to a more complex angle ambiguity problem. To eliminate ambiguity, we theoretically prove that the actual DOAs of noncircular signals can be uniquely estimated by finding the coincide results from the two decomposed subarrays based on the coprimeness. We propose a locally reduced-dimensional (RD) Capon algorithm for DOA estimation of noncircular signals for CLA. The RD processing is used in the proposed algorithm to avoid two dimensional (2D) spectral peak search, and coprimeness is employed to avoid the global spectral peak search. The proposed algorithm requires one-dimensional locally spectral peak search, and it has very low computational complexity. Furthermore, the proposed algorithm needs no prior knowledge of the number of sources. We also derive the Crámer-Rao bound of DOA estimation of noncircular signals in CLA. Numerical simulation results demonstrate the effectiveness and superiority of the algorithm.
Genetic algorithm-based improved DOA estimation using fourth-order cumulants
NASA Astrophysics Data System (ADS)
Ahmed, Ammar; Tufail, Muhammad
2017-05-01
Genetic algorithm (GA)-based direction of arrival (DOA) estimation is proposed using fourth-order cumulants (FOC) and ESPRIT principle which results in Multiple Invariance Cumulant ESPRIT algorithm. In the existing FOC ESPRIT formulations, only one invariance is utilised to estimate DOAs. The unused multiple invariances (MIs) must be exploited simultaneously in order to improve the estimation accuracy. In this paper, a fitness function based on a carefully designed cumulant matrix is developed which incorporates MIs present in the sensor array. Better DOA estimation can be achieved by minimising this fitness function. Moreover, the effectiveness of Newton's method as well as GA for this optimisation problem has been illustrated. Simulation results show that the proposed algorithm provides improved estimation accuracy compared to existing algorithms, especially in the case of low SNR, less number of snapshots, closely spaced sources and high signal and noise correlation. Moreover, it is observed that the optimisation using Newton's method is more likely to converge to false local optima resulting in erroneous results. However, GA-based optimisation has been found attractive due to its global optimisation capability.
Stapled haemorrhoidectomy in the operative treatment of grade III and IV haemorrhoids.
Shrestha, S; Pradhan, G B N; Shrestha, R; Poudel, P; Bhattachan, C L
2014-09-01
Stapled haemorrhoidectomy (SH) is a minimally invasive intervention that uses a stapling device which avoids the need for wounds in the sensitive anal area and reduces the pain after surgery. This study was undertaken in Nepal Medical College Teaching Hospital from January 2010 to December 2012 to evaluate the efficacy of this modality of treatment among patients (32) who presented in the Surgery OPD with grade III and grade IV haemorrhoids. The results of SH were evaluated by the relief of symptoms, severity of post operative pain, and complications of SH. Twenty five (78.1%) patients had grade III and 7 (21.9%) presented with grade IV hemorrhoids. The most frequent presentation reported in our study was bleeding per rectum with perianal prolapse. Mean operating time was 40-60 minutes whereas mean hospital stay was 1.9 days. Urinary retention was the most common complication found in 12 (37.5%) patients in the immediate post operative period. SH is a safe, rapid, and convenient surgical remedy for grade III and grade IV hemorrhoids with low rate of complications, minimal postoperative pain, and shorter hospital stay.
Abhary, Mohammad; Siritunga, Dimuth; Stevens, Gene; Taylor, Nigel J.; Fauquet, Claude M.
2011-01-01
Although calorie dense, the starchy, tuberous roots of cassava provide the lowest sources of dietary protein within the major staple food crops (Manihot esculenta Crantz). (Montagnac JA, Davis CR, Tanumihardjo SA. (2009) Compr Rev Food Sci Food Saf 8:181–194). Cassava was genetically modified to express zeolin, a nutritionally balanced storage protein under control of the patatin promoter. Transgenic plants accumulated zeolin within de novo protein bodies localized within the root storage tissues, resulting in total protein levels of 12.5% dry weight within this tissue, a fourfold increase compared to non-transgenic controls. No significant differences were seen for morphological or agronomic characteristics of transgenic and wild type plants in the greenhouse and field trials, but relative to controls, levels of cyanogenic compounds were reduced by up to 55% in both leaf and root tissues of transgenic plants. Data described here represent a proof of concept towards the potential transformation of cassava from a starchy staple, devoid of storage protein, to one capable of supplying inexpensive, plant-based proteins for food, feed and industrial applications. PMID:21283593
Abhary, Mohammad; Siritunga, Dimuth; Stevens, Gene; Taylor, Nigel J; Fauquet, Claude M
2011-01-25
Although calorie dense, the starchy, tuberous roots of cassava provide the lowest sources of dietary protein within the major staple food crops (Manihot esculenta Crantz). (Montagnac JA, Davis CR, Tanumihardjo SA. (2009) Compr Rev Food Sci Food Saf 8:181-194). Cassava was genetically modified to express zeolin, a nutritionally balanced storage protein under control of the patatin promoter. Transgenic plants accumulated zeolin within de novo protein bodies localized within the root storage tissues, resulting in total protein levels of 12.5% dry weight within this tissue, a fourfold increase compared to non-transgenic controls. No significant differences were seen for morphological or agronomic characteristics of transgenic and wild type plants in the greenhouse and field trials, but relative to controls, levels of cyanogenic compounds were reduced by up to 55% in both leaf and root tissues of transgenic plants. Data described here represent a proof of concept towards the potential transformation of cassava from a starchy staple, devoid of storage protein, to one capable of supplying inexpensive, plant-based proteins for food, feed and industrial applications.
Rosser, Julie; Brounts, Sabrina; Slone, Don; Lynch, Tim; Livesey, Michael; Hughes, Faith; Clark, Carol
2012-01-01
Our objective was to compare survival and complication rates of horses undergoing pelvic flexure enterotomy closure with a TA-90 stapler to those with hand-sewn closure. Medical records of horses undergoing pelvic flexure enterotomy between 2001 and 2008 were reviewed. History, clinical signs, surgical findings, surgical techniques, and post-operative complications were recorded. Long-term outcome was established by telephone questionnaire. Of 84 pelvic flexure enterotomies performed, 70 were stapled and 14 were hand-sewn. Seventy-seven horses survived to discharge (91.7%). There were no significant associations between survival and closure technique (P = 0.69). Follow-up was available for 54 horses; 50 survived long-term (93.0%). No statistical significance was identified between long-term survival and closure method (P = 0.39). Forty horses went on to athletic performance (80.0%). TA-90 stapled closure of pelvic flexure enterotomies is a safe technique resulting in survival and complication rates equivalent to those of hand-sewn closure. PMID:23204584
Howell, G. P.; Ryan, J. M.; Morgans, B. T.; Cooper, G. J.
1991-01-01
Laparotomy and anastomosis of the small bowel after penetrating injury to the abdomen is a lengthy procedure. This paper describes the use of skin staplers for bowel anastomosis and presents the results of a short series of experiments upon dead pigs to compare the staple technique with conventional handsewn anastomosis. The time taken to perform each small bowel anastomosis, the integrity of the anastomosis and the skill required were assessed. The staple technique was considerably faster (mean construction time: 5.4 min, range 4-6 min) than the handsewn technique (mean construction time: 12 min, range 10-14 min), at least halving the anastomosis time (Kolmogorov two-sample test P = 0.05). In addition, the stapled anastomosis had a higher intraluminal failure pressure (mean failure pressure: 65 cmH2O, 6.37 kPa, range 30-70 cmH2O) than the handsewn anastomosis (mean failure pressure: 38.6 cmH2O, 3.78 kPa, range 10-70 cmH2O). Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:2018326
Fleetwood, V A; Gross, K N; Alex, G C; Cortina, C S; Smolevitz, J B; Sarvepalli, S; Bakhsh, S R; Poirier, J; Myers, J A; Singer, M A; Orkin, B A
2017-03-01
Anastomotic leak (AL) increases costs and cancer recurrence. Studies show decreased AL with side-to-side stapled anastomosis (SSA), but none identify risk factors within SSAs. We hypothesized that stapler characteristics and closure technique of the common enterotomy affect AL rates. Retrospective review of bowel SSAs was performed. Data included stapler brand, staple line oversewing, and closure method (handsewn, HC; linear stapler [Barcelona technique], BT; transverse stapler, TX). Primary endpoint was AL. Statistical analysis included Fisher's test and logistic regression. 463 patients were identified, 58.5% BT, 21.2% HC, and 20.3% TX. Covidien staplers comprised 74.9%, Ethicon 18.1%. There were no differences between stapler types (Covidien 5.8%, Ethicon 6.0%). However, AL rates varied by common side closure (BT 3.7% vs. TX 10.6%, p = 0.017), remaining significant on multivariate analysis. Closure method of the common side impacts AL rates. Barcelona technique has fewer leaks than transverse stapled closure. Further prospective evaluation is recommended. Copyright © 2017. Published by Elsevier Inc.
Tang, Shou-Jiang; Rivas, Homero; Tang, Linda; Lara, Luis F; Sreenarasimhaiah, Jayaprakash; Rockey, Don C
2007-09-01
Roux-en-Y gastric bypass (RYGBP) is the most commonly performed bariatric operation in the USA. In the early postoperative stage, gastrointestinal (GI) bleeding is an infrequent but potentially serious complication that usually results from bleeding at the gastrojejunostomy staple-line. Observant management with transfusion for stable patients and surgical exploration for unstable patients is typically recommended for early GI bleeding. We hypothesized that use of endoclips, which do not cause thermal injury to the surrounding tissues (or anastomosis), may be preferable to thermal approaches which could cause tissue injury. We report 2 cases of early GI bleeding after RYGBP that were successfully managed with endoclip application to bleeding lesions. Emergent endoscopy was performed, and major stigmata such as active spurting vessel and adherent clot were noted at the gastrojejunostomy staple-lines. Endoscopic hemostasis using endoclips was readily applied to bleeding lesions at staple-lines. Primary hemostasis was achieved, and there was no recurrent bleeding or complication. We conclude that therapeutic endoscopy can be performed safely for early bleeding after RYGBP. In patients with early bleeding after RYGBP, use of endoclips is mechanistically preferable to other options.
A simplified technique for continent urinary diversion: an all-stapled colonic reservoir.
Parra, R O
1991-12-01
A simple continent colonic reservoir was constructed in its entirety with the aid of surgical stapling techniques in 17 men and 10 women. In 5 men an orthotopic pouch was created and in the rest a continent stoma was designed. Detubularization of the entire colonic segment assures a low pressure system with disruption of directional peristaltic activity. The ureters are implanted by simply burying them in a mucosal furrow. Operative time required for the creation of the reservoir (excluding time for cystectomy) has ranged between 70 and 140 minutes (mean 95.4 minutes). With a followup of 9 to 60 months (mean 22.8 months) continence has been achieved in all but 1 patient with no ureteral reflux or obstruction. Urodynamically the pouch has achieved a large capacity (mean 750 cc) with low filling pressures (8.1 cm. water) because of technical ease of construction together with a shortened operative time due to the stapling techniques. This form of bladder replacement offers an option for select patients in whom continent urinary diversion is contemplated.
Forsido, Sirawdink Fikreyesus; Rupasinghe, H P Vasantha; Astatkie, Tess
2013-12-01
The total antioxidant capacity, total phenolics content (TPC) and nutritional content of five types of enset (Enset ventricosum) flour in comparison with four staples (teff [Eragrostis tef], wheat, corn and tapioca) were evaluated. Teff, corn and "amicho" (corm of enset) had the highest ferric reducing antioxidant power (FRAP). The FRAP and TPC of teff (1.8 mmol Trolox equivalence/100 g dry matter (DM) and 123.6 mg gallic acid equivalent/100 g DM, respectively) were over 4-fold larger than the lowest obtained from "bulla" (dehydrated juice of pseudostem of enset). Corn had the lowest IC(50) value of 1,1-diphenyl-2-picrylhydrazyl radical scavenging (10.27 mg DM mL(-1)). Teff had the highest crude fat content (3.71%) and some mineral profile (P, Mg, Mn and Cu). Enset products had higher fiber, Ca, K, Mg and Mn content as compared to wheat and corn. Ethiopian staple teff has a potential for developing value-added food products with nutritional and health benefits.
Mongardini, M; Custureri, F; Schillaci, F; Cola, A; Maturo, A; Fanello, G; Corelli, S; Pappalardo, G
2005-04-01
Intra- and early (first week) post-operative haemorrhages are the most common complications in stapled hemorrhoidectomy PPH (Procedure for Prolapse and Hemorrhoids) and in circumferential resection of the rectal prolapse STARR (Stapled Trans Anal Rectal Resection). Performing PPH and STARR we employed a gelatin based haemostatic sealant with thrombin component (FloSeal) to control intra-operative bleeding and to reduce post-operative bleeding avoiding haemostatic stitches on suture line. We report the preliminary results on 197 PPH and 64 STARR; 44 PPH (22.4%) and 27 STARR (42.2%) were treated by FloSeal. No major post-operative bleeding was observed in all patients treated by FloSeal, compared to 1.3% and 2.7% of hemorrhage respectively in PPH and STARR patients treated without sealant. Post-operative pain was less severe in patients treated by FloSeal, without a difference statistically significant. The data are preliminary and must be confirmed in prospective randomized trials in larger series.
Closed-Form 3-D Localization for Single Source in Uniform Circular Array with a Center Sensor
NASA Astrophysics Data System (ADS)
Bae, Eun-Hyon; Lee, Kyun-Kyung
A novel closed-form algorithm is presented for estimating the 3-D location (azimuth angle, elevation angle, and range) of a single source in a uniform circular array (UCA) with a center sensor. Based on the centrosymmetry of the UCA and noncircularity of the source, the proposed algorithm decouples and estimates the 2-D direction of arrival (DOA), i.e. azimuth and elevation angles, and then estimates the range of the source. Notwithstanding a low computational complexity, the proposed algorithm provides an estimation performance close to that of the benchmark estimator 3-D MUSIC.
NASA Astrophysics Data System (ADS)
Khambampati, A. K.; Rashid, A.; Kim, B. S.; Liu, Dong; Kim, S.; Kim, K. Y.
2010-04-01
EIT has been used for the dynamic estimation of organ boundaries. One specific application in this context is the estimation of lung boundaries during pulmonary circulation. This would help track the size and shape of lungs of the patients suffering from diseases like pulmonary edema and acute respiratory failure (ARF). The dynamic boundary estimation of the lungs can also be utilized to set and control the air volume and pressure delivered to the patients during artificial ventilation. In this paper, the expectation-maximization (EM) algorithm is used as an inverse algorithm to estimate the non-stationary lung boundary. The uncertainties caused in Kalman-type filters due to inaccurate selection of model parameters are overcome using EM algorithm. Numerical experiments using chest shaped geometry are carried out with proposed method and the performance is compared with extended Kalman filter (EKF). Results show superior performance of EM in estimation of the lung boundary.
Quantum speedup of Monte Carlo methods.
Montanaro, Ashley
2015-09-08
Monte Carlo methods use random sampling to estimate numerical quantities which are hard to compute deterministically. One important example is the use in statistical physics of rapidly mixing Markov chains to approximately compute partition functions. In this work, we describe a quantum algorithm which can accelerate Monte Carlo methods in a very general setting. The algorithm estimates the expected output value of an arbitrary randomized or quantum subroutine with bounded variance, achieving a near-quadratic speedup over the best possible classical algorithm. Combining the algorithm with the use of quantum walks gives a quantum speedup of the fastest known classical algorithms with rigorous performance bounds for computing partition functions, which use multiple-stage Markov chain Monte Carlo techniques. The quantum algorithm can also be used to estimate the total variation distance between probability distributions efficiently.
Quantum speedup of Monte Carlo methods
Montanaro, Ashley
2015-01-01
Monte Carlo methods use random sampling to estimate numerical quantities which are hard to compute deterministically. One important example is the use in statistical physics of rapidly mixing Markov chains to approximately compute partition functions. In this work, we describe a quantum algorithm which can accelerate Monte Carlo methods in a very general setting. The algorithm estimates the expected output value of an arbitrary randomized or quantum subroutine with bounded variance, achieving a near-quadratic speedup over the best possible classical algorithm. Combining the algorithm with the use of quantum walks gives a quantum speedup of the fastest known classical algorithms with rigorous performance bounds for computing partition functions, which use multiple-stage Markov chain Monte Carlo techniques. The quantum algorithm can also be used to estimate the total variation distance between probability distributions efficiently. PMID:26528079
Clinical validation of the General Ability Index--Estimate (GAI-E): estimating premorbid GAI.
Schoenberg, Mike R; Lange, Rael T; Iverson, Grant L; Chelune, Gordon J; Scott, James G; Adams, Russell L
2006-09-01
The clinical utility of the General Ability Index--Estimate (GAI-E; Lange, Schoenberg, Chelune, Scott, & Adams, 2005) for estimating premorbid GAI scores was investigated using the WAIS-III standardization clinical trials sample (The Psychological Corporation, 1997). The GAI-E algorithms combine Vocabulary, Information, Matrix Reasoning, and Picture Completion subtest raw scores with demographic variables to predict GAI. Ten GAI-E algorithms were developed combining demographic variables with single subtest scaled scores and with two subtests. Estimated GAI are presented for participants diagnosed with dementia (n = 50), traumatic brain injury (n = 20), Huntington's disease (n = 15), Korsakoff's disease (n = 12), chronic alcohol abuse (n = 32), temporal lobectomy (n = 17), and schizophrenia (n = 44). In addition, a small sample of participants without dementia and diagnosed with depression (n = 32) was used as a clinical comparison group. The GAI-E algorithms provided estimates of GAI that closely approximated scores expected for a healthy adult population. The greatest differences between estimated GAI and obtained GAI were observed for the single subtest GAI-E algorithms using the Vocabulary, Information, and Matrix Reasoning subtests. Based on these data, recommendations for the use of the GAI-E algorithms are presented.
The MAP Spacecraft Angular State Estimation After Sensor Failure
NASA Technical Reports Server (NTRS)
Bar-Itzhack, Itzhack Y.; Harman, Richard R.
2003-01-01
This work describes two algorithms for computing the angular rate and attitude in case of a gyro and a Star Tracker failure in the Microwave Anisotropy Probe (MAP) satellite, which was placed in the L2 parking point from where it collects data to determine the origin of the universe. The nature of the problem is described, two algorithms are suggested, an observability study is carried out and real MAP data are used to determine the merit of the algorithms. It is shown that one of the algorithms yields a good estimate of the rates but not of the attitude whereas the other algorithm yields a good estimate of the rate as well as two of the three attitude angles. The estimation of the third angle depends on the initial state estimate. There is a contradiction between this result and the outcome of the observability analysis. An explanation of this contradiction is given in the paper. Although this work treats a particular spacecraft, the conclusions have a far reaching consequence.
The Effect of Sensor Failure on the Attitude and Rate Estimation of MAP Spacecraft
NASA Technical Reports Server (NTRS)
Bar-Itzhack, Itzhack Y.; Harman, Richard R.
2003-01-01
This work describes two algorithms for computing the angular rate and attitude in case of a gyro and a Star Tracker failure in the Microwave Anisotropy Probe (MAP) satellite, which was placed in the L2 parking point from where it collects data to determine the origin of the universe. The nature of the problem is described, two algorithms are suggested, an observability study is carried out and real MAP data are used to determine the merit of the algorithms. It is shown that one of the algorithms yields a good estimate of the rates but not of the attitude whereas the other algorithm yields a good estimate of the rate as well as two of the three attitude angles. The estimation of the third angle depends on the initial state estimate. There is a contradiction between this result and the outcome of the observability analysis. An explanation of this contradiction is given in the paper. Although this work treats a particular spacecraft, its conclusions are more general.
Linearized motion estimation for articulated planes.
Datta, Ankur; Sheikh, Yaser; Kanade, Takeo
2011-04-01
In this paper, we describe the explicit application of articulation constraints for estimating the motion of a system of articulated planes. We relate articulations to the relative homography between planes and show that these articulations translate into linearized equality constraints on a linear least-squares system, which can be solved efficiently using a Karush-Kuhn-Tucker system. The articulation constraints can be applied for both gradient-based and feature-based motion estimation algorithms and to illustrate this, we describe a gradient-based motion estimation algorithm for an affine camera and a feature-based motion estimation algorithm for a projective camera that explicitly enforces articulation constraints. We show that explicit application of articulation constraints leads to numerically stable estimates of motion. The simultaneous computation of motion estimates for all of the articulated planes in a scene allows us to handle scene areas where there is limited texture information and areas that leave the field of view. Our results demonstrate the wide applicability of the algorithm in a variety of challenging real-world cases such as human body tracking, motion estimation of rigid, piecewise planar scenes, and motion estimation of triangulated meshes.
Sensor failure detection for jet engines
NASA Technical Reports Server (NTRS)
Beattie, E. C.; Laprad, R. F.; Akhter, M. M.; Rock, S. M.
1983-01-01
Revisions to the advanced sensor failure detection, isolation, and accommodation (DIA) algorithm, developed under the sensor failure detection system program were studied to eliminate the steady state errors due to estimation filter biases. Three algorithm revisions were formulated and one revision for detailed evaluation was chosen. The selected version modifies the DIA algorithm to feedback the actual sensor outputs to the integral portion of the control for the nofailure case. In case of a failure, the estimates of the failed sensor output is fed back to the integral portion. The estimator outputs are fed back to the linear regulator portion of the control all the time. The revised algorithm is evaluated and compared to the baseline algorithm developed previously.
NASA Astrophysics Data System (ADS)
MOHAMMED, M. A. SI; BOUSSADIA, H.; BELLAR, A.; ADNANE, A.
2017-01-01
This paper presents a brief synthesis and useful performance analysis of different attitude filtering algorithms (attitude determination algorithms, attitude estimation algorithms, and nonlinear observers) applied to Low Earth Orbit Satellite in terms of accuracy, convergence time, amount of memory, and computation time. This latter is calculated in two ways, using a personal computer and also using On-board computer 750 (OBC 750) that is being used in many SSTL Earth observation missions. The use of this comparative study could be an aided design tool to the designer to choose from an attitude determination or attitude estimation or attitude observer algorithms. The simulation results clearly indicate that the nonlinear Observer is the more logical choice.
Zhang, Zhihua; Sheng, Zheng; Shi, Hanqing; Fan, Zhiqiang
2016-01-01
Using the RFC technique to estimate refractivity parameters is a complex nonlinear optimization problem. In this paper, an improved cuckoo search (CS) algorithm is proposed to deal with this problem. To enhance the performance of the CS algorithm, a parameter dynamic adaptive operation and crossover operation were integrated into the standard CS (DACS-CO). Rechenberg's 1/5 criteria combined with learning factor were used to control the parameter dynamic adaptive adjusting process. The crossover operation of genetic algorithm was utilized to guarantee the population diversity. The new hybrid algorithm has better local search ability and contributes to superior performance. To verify the ability of the DACS-CO algorithm to estimate atmospheric refractivity parameters, the simulation data and real radar clutter data are both implemented. The numerical experiments demonstrate that the DACS-CO algorithm can provide an effective method for near-real-time estimation of the atmospheric refractivity profile from radar clutter. PMID:27212938
NASA Astrophysics Data System (ADS)
Gilat-Schmidt, Taly; Wang, Adam; Coradi, Thomas; Haas, Benjamin; Star-Lack, Josh
2016-03-01
The overall goal of this work is to develop a rapid, accurate and fully automated software tool to estimate patient-specific organ doses from computed tomography (CT) scans using a deterministic Boltzmann Transport Equation solver and automated CT segmentation algorithms. This work quantified the accuracy of organ dose estimates obtained by an automated segmentation algorithm. The investigated algorithm uses a combination of feature-based and atlas-based methods. A multiatlas approach was also investigated. We hypothesize that the auto-segmentation algorithm is sufficiently accurate to provide organ dose estimates since random errors at the organ boundaries will average out when computing the total organ dose. To test this hypothesis, twenty head-neck CT scans were expertly segmented into nine regions. A leave-one-out validation study was performed, where every case was automatically segmented with each of the remaining cases used as the expert atlas, resulting in nineteen automated segmentations for each of the twenty datasets. The segmented regions were applied to gold-standard Monte Carlo dose maps to estimate mean and peak organ doses. The results demonstrated that the fully automated segmentation algorithm estimated the mean organ dose to within 10% of the expert segmentation for regions other than the spinal canal, with median error for each organ region below 2%. In the spinal canal region, the median error was 7% across all data sets and atlases, with a maximum error of 20%. The error in peak organ dose was below 10% for all regions, with a median error below 4% for all organ regions. The multiple-case atlas reduced the variation in the dose estimates and additional improvements may be possible with more robust multi-atlas approaches. Overall, the results support potential feasibility of an automated segmentation algorithm to provide accurate organ dose estimates.
NASA Technical Reports Server (NTRS)
Olson, William S.; Kummerow, Christian D.; Yang, Song; Petty, Grant W.; Tao, Wei-Kuo; Bell, Thomas L.; Braun, Scott A.; Wang, Yansen; Lang, Stephen E.; Johnson, Daniel E.
2004-01-01
A revised Bayesian algorithm for estimating surface rain rate, convective rain proportion, and latent heating/drying profiles from satellite-borne passive microwave radiometer observations over ocean backgrounds is described. The algorithm searches a large database of cloud-radiative model simulations to find cloud profiles that are radiatively consistent with a given set of microwave radiance measurements. The properties of these radiatively consistent profiles are then composited to obtain best estimates of the observed properties. The revised algorithm is supported by an expanded and more physically consistent database of cloud-radiative model simulations. The algorithm also features a better quantification of the convective and non-convective contributions to total rainfall, a new geographic database, and an improved representation of background radiances in rain-free regions. Bias and random error estimates are derived from applications of the algorithm to synthetic radiance data, based upon a subset of cloud resolving model simulations, and from the Bayesian formulation itself. Synthetic rain rate and latent heating estimates exhibit a trend of high (low) bias for low (high) retrieved values. The Bayesian estimates of random error are propagated to represent errors at coarser time and space resolutions, based upon applications of the algorithm to TRMM Microwave Imager (TMI) data. Errors in instantaneous rain rate estimates at 0.5 deg resolution range from approximately 50% at 1 mm/h to 20% at 14 mm/h. These errors represent about 70-90% of the mean random deviation between collocated passive microwave and spaceborne radar rain rate estimates. The cumulative algorithm error in TMI estimates at monthly, 2.5 deg resolution is relatively small (less than 6% at 5 mm/day) compared to the random error due to infrequent satellite temporal sampling (8-35% at the same rain rate).
Blood Pressure Monitoring for the Anesthesiologist: A Practical Review.
Bartels, Karsten; Esper, Stephen A; Thiele, Robert H
2016-06-01
Periodic, quantitative measurement of blood pressure (BP) in humans, predating the era of evidence-based medicine by over a century, is a component of the American Society of Anesthesiologists standards for basic anesthetic monitoring and is a staple of anesthetic management worldwide. Adherence to traditional BP parameters complicates the ability of investigators to determine whether particular BP ranges confer any clinical benefits. The BP waveform is a complex amalgamation of both antegrade and retrograde (reflected) pressure waves and is affected by vascular compliance, distance from the left ventricle, and the 3D structure of the vascular tree. Although oscillometry is the standard method of measuring BP semicontinuously in anesthetized patients and is the primary form of measurement in >80% of general anesthetics, major shortcomings of oscillometry are its poor performance at the extremes and its lack of information concerning BP waveform. Although arterial catheterization remains the gold standard for accurate BP measurement, 2 classes of devices have been developed to noninvasively measure the BP waveform continuously, including tonometric and volume clamp devices. Described in terms of a feedback loop, control of BP requires measurement, an algorithm (usually human), and an intervention. This narrative review article discusses the details of BP measurement and the advantages and disadvantages of both noninvasive and invasive monitoring, as well as the principles and algorithms associated with each technique.
Development of Parallel Architectures for Sensor Array Processing. Volume 1
1993-08-01
required for the DOA estimation [ 1-7]. The Multiple Signal Classification ( MUSIC ) [ 1] and the Estimation of Signal Parameters by Rotational...manifold and the estimated subspace. Although MUSIC is a high resolution algorithm, it has several drawbacks including the fact that complete knowledge of...thoroughly, MUSIC algorithm was selected to develop special purpose hardware for real time computation. Summary of the MUSIC algorithm is as follows
Extended reactance domain algorithms for DoA estimation onto an ESPAR antennas
NASA Astrophysics Data System (ADS)
Harabi, F.; Akkar, S.; Gharsallah, A.
2016-07-01
Based on an extended reactance domain (RD) covariance matrix, this article proposes new alternatives for directions of arrival (DoAs) estimation of narrowband sources through an electronically steerable parasitic array radiator (ESPAR) antennas. Because of the centro symmetry of the classic ESPAR antennas, an unitary transformation is applied to the collected data that allow an important reduction in both computational cost and processing time and, also, an enhancement of the resolution capabilities of the proposed algorithms. Moreover, this article proposes a new approach for eigenvalues estimation through only some linear operations. The developed DoAs estimation algorithms based on this new approach has illustrated a good behaviour with less calculation cost and processing time as compared to other schemes based on the classic eigenvalues approach. The conducted simulations demonstrate that high-precision and high-resolution DoAs estimation can be reached especially in very closely sources situation and low sources power as compared to the RD-MUSIC algorithm and the RD-PM algorithm. The asymptotic behaviours of the proposed DoAs estimators are analysed in various scenarios and compared with the Cramer-Rao bound (CRB). The conducted simulations testify the high-resolution of the developed algorithms and prove the efficiently of the proposed approach.
Gao, Yu-Fei; Gui, Guan; Xie, Wei; Zou, Yan-Bin; Yang, Yue; Wan, Qun
2017-01-01
This paper investigates a two-dimensional angle of arrival (2D AOA) estimation algorithm for the electromagnetic vector sensor (EMVS) array based on Type-2 block component decomposition (BCD) tensor modeling. Such a tensor decomposition method can take full advantage of the multidimensional structural information of electromagnetic signals to accomplish blind estimation for array parameters with higher resolution. However, existing tensor decomposition methods encounter many restrictions in applications of the EMVS array, such as the strict requirement for uniqueness conditions of decomposition, the inability to handle partially-polarized signals, etc. To solve these problems, this paper investigates tensor modeling for partially-polarized signals of an L-shaped EMVS array. The 2D AOA estimation algorithm based on rank-(L1,L2,·) BCD is developed, and the uniqueness condition of decomposition is analyzed. By means of the estimated steering matrix, the proposed algorithm can automatically achieve angle pair-matching. Numerical experiments demonstrate that the present algorithm has the advantages of both accuracy and robustness of parameter estimation. Even under the conditions of lower SNR, small angular separation and limited snapshots, the proposed algorithm still possesses better performance than subspace methods and the canonical polyadic decomposition (CPD) method. PMID:28448431
An open source framework for tracking and state estimation ('Stone Soup')
NASA Astrophysics Data System (ADS)
Thomas, Paul A.; Barr, Jordi; Balaji, Bhashyam; White, Kruger
2017-05-01
The ability to detect and unambiguously follow all moving entities in a state-space is important in multiple domains both in defence (e.g. air surveillance, maritime situational awareness, ground moving target indication) and the civil sphere (e.g. astronomy, biology, epidemiology, dispersion modelling). However, tracking and state estimation researchers and practitioners have difficulties recreating state-of-the-art algorithms in order to benchmark their own work. Furthermore, system developers need to assess which algorithms meet operational requirements objectively and exhaustively rather than intuitively or driven by personal favourites. We have therefore commenced the development of a collaborative initiative to create an open source framework for production, demonstration and evaluation of Tracking and State Estimation algorithms. The initiative will develop a (MIT-licensed) software platform for researchers and practitioners to test, verify and benchmark a variety of multi-sensor and multi-object state estimation algorithms. The initiative is supported by four defence laboratories, who will contribute to the development effort for the framework. The tracking and state estimation community will derive significant benefits from this work, including: access to repositories of verified and validated tracking and state estimation algorithms, a framework for the evaluation of multiple algorithms, standardisation of interfaces and access to challenging data sets. Keywords: Tracking,
Gao, Yu-Fei; Gui, Guan; Xie, Wei; Zou, Yan-Bin; Yang, Yue; Wan, Qun
2017-04-27
This paper investigates a two-dimensional angle of arrival (2D AOA) estimation algorithm for the electromagnetic vector sensor (EMVS) array based on Type-2 block component decomposition (BCD) tensor modeling. Such a tensor decomposition method can take full advantage of the multidimensional structural information of electromagnetic signals to accomplish blind estimation for array parameters with higher resolution. However, existing tensor decomposition methods encounter many restrictions in applications of the EMVS array, such as the strict requirement for uniqueness conditions of decomposition, the inability to handle partially-polarized signals, etc. To solve these problems, this paper investigates tensor modeling for partially-polarized signals of an L-shaped EMVS array. The 2D AOA estimation algorithm based on rank- ( L 1 , L 2 , · ) BCD is developed, and the uniqueness condition of decomposition is analyzed. By means of the estimated steering matrix, the proposed algorithm can automatically achieve angle pair-matching. Numerical experiments demonstrate that the present algorithm has the advantages of both accuracy and robustness of parameter estimation. Even under the conditions of lower SNR, small angular separation and limited snapshots, the proposed algorithm still possesses better performance than subspace methods and the canonical polyadic decomposition (CPD) method.
NASA Astrophysics Data System (ADS)
Yuan, Chunhua; Wang, Jiang; Yi, Guosheng
2017-03-01
Estimation of ion channel parameters is crucial to spike initiation of neurons. The biophysical neuron models have numerous ion channel parameters, but only a few of them play key roles in the firing patterns of the models. So we choose three parameters featuring the adaptation in the Ermentrout neuron model to be estimated. However, the traditional particle swarm optimization (PSO) algorithm is still easy to fall into local optimum and has the premature convergence phenomenon in the study of some problems. In this paper, we propose an improved method that uses a concave function and dynamic logistic chaotic mapping mixed to adjust the inertia weights of the fitness value, effectively improve the global convergence ability of the algorithm. The perfect predicting firing trajectories of the rebuilt model using the estimated parameters prove that only estimating a few important ion channel parameters can establish the model well and the proposed algorithm is effective. Estimations using two classic PSO algorithms are also compared to the improved PSO to verify that the algorithm proposed in this paper can avoid local optimum and quickly converge to the optimal value. The results provide important theoretical foundations for building biologically realistic neuron models.
Koay, Cheng Guan; Chang, Lin-Ching; Carew, John D; Pierpaoli, Carlo; Basser, Peter J
2006-09-01
A unifying theoretical and algorithmic framework for diffusion tensor estimation is presented. Theoretical connections among the least squares (LS) methods, (linear least squares (LLS), weighted linear least squares (WLLS), nonlinear least squares (NLS) and their constrained counterparts), are established through their respective objective functions, and higher order derivatives of these objective functions, i.e., Hessian matrices. These theoretical connections provide new insights in designing efficient algorithms for NLS and constrained NLS (CNLS) estimation. Here, we propose novel algorithms of full Newton-type for the NLS and CNLS estimations, which are evaluated with Monte Carlo simulations and compared with the commonly used Levenberg-Marquardt method. The proposed methods have a lower percent of relative error in estimating the trace and lower reduced chi2 value than those of the Levenberg-Marquardt method. These results also demonstrate that the accuracy of an estimate, particularly in a nonlinear estimation problem, is greatly affected by the Hessian matrix. In other words, the accuracy of a nonlinear estimation is algorithm-dependent. Further, this study shows that the noise variance in diffusion weighted signals is orientation dependent when signal-to-noise ratio (SNR) is low (
NASA Astrophysics Data System (ADS)
Li, Xinya; Deng, Zhiqun Daniel; Rauchenstein, Lynn T.; Carlson, Thomas J.
2016-04-01
Locating the position of fixed or mobile sources (i.e., transmitters) based on measurements obtained from sensors (i.e., receivers) is an important research area that is attracting much interest. In this paper, we review several representative localization algorithms that use time of arrivals (TOAs) and time difference of arrivals (TDOAs) to achieve high signal source position estimation accuracy when a transmitter is in the line-of-sight of a receiver. Circular (TOA) and hyperbolic (TDOA) position estimation approaches both use nonlinear equations that relate the known locations of receivers and unknown locations of transmitters. Estimation of the location of transmitters using the standard nonlinear equations may not be very accurate because of receiver location errors, receiver measurement errors, and computational efficiency challenges that result in high computational burdens. Least squares and maximum likelihood based algorithms have become the most popular computational approaches to transmitter location estimation. In this paper, we summarize the computational characteristics and position estimation accuracies of various positioning algorithms. By improving methods for estimating the time-of-arrival of transmissions at receivers and transmitter location estimation algorithms, transmitter location estimation may be applied across a range of applications and technologies such as radar, sonar, the Global Positioning System, wireless sensor networks, underwater animal tracking, mobile communications, and multimedia.
Fast frequency acquisition via adaptive least squares algorithm
NASA Technical Reports Server (NTRS)
Kumar, R.
1986-01-01
A new least squares algorithm is proposed and investigated for fast frequency and phase acquisition of sinusoids in the presence of noise. This algorithm is a special case of more general, adaptive parameter-estimation techniques. The advantages of the algorithms are their conceptual simplicity, flexibility and applicability to general situations. For example, the frequency to be acquired can be time varying, and the noise can be nonGaussian, nonstationary and colored. As the proposed algorithm can be made recursive in the number of observations, it is not necessary to have a priori knowledge of the received signal-to-noise ratio or to specify the measurement time. This would be required for batch processing techniques, such as the fast Fourier transform (FFT). The proposed algorithm improves the frequency estimate on a recursive basis as more and more observations are obtained. When the algorithm is applied in real time, it has the extra advantage that the observations need not be stored. The algorithm also yields a real time confidence measure as to the accuracy of the estimator.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baldini, Elizabeth H., E-mail: ebaldini@partners.org; Abrams, Ross A.; Bosch, Walter
Purpose: The purpose of this study was to evaluate the variability in target volume and organ at risk (OAR) contour delineation for retroperitoneal sarcoma (RPS) among 12 sarcoma radiation oncologists. Methods and Materials: Radiation planning computed tomography (CT) scans for 2 cases of RPS were distributed among 12 sarcoma radiation oncologists with instructions for contouring gross tumor volume (GTV), clinical target volume (CTV), high-risk CTV (HR CTV: area judged to be at high risk of resulting in positive margins after resection), and OARs: bowel bag, small bowel, colon, stomach, and duodenum. Analysis of contour agreement was performed using the simultaneousmore » truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results: Ten radiation oncologists contoured both RPS cases, 1 contoured only RPS1, and 1 contoured only RPS2 such that each case was contoured by 11 radiation oncologists. The first case (RPS 1) was a patient with a de-differentiated (DD) liposarcoma (LPS) with a predominant well-differentiated (WD) component, and the second case (RPS 2) was a patient with DD LPS made up almost entirely of a DD component. Contouring agreement for GTV and CTV contours was high. However, the agreement for HR CTVs was only moderate. For OARs, agreement for stomach, bowel bag, small bowel, and colon was high, but agreement for duodenum (distorted by tumor in one of these cases) was fair to moderate. Conclusions: For preoperative treatment of RPS, sarcoma radiation oncologists contoured GTV, CTV, and most OARs with a high level of agreement. HR CTV contours were more variable. Further clarification of this volume with the help of sarcoma surgical oncologists is necessary to reach consensus. More attention to delineation of the duodenum is also needed.« less
Baldini, Elizabeth H.; Abrams, Ross A.; Bosch, Walter; Roberge, David; Haas, Rick L.M.; Catton, Charles N.; Indelicato, Daniel J.; Olsen, Jeffrey R.; Deville, Curtiland; Chen, Yen-Lin; Finkelstein, Steven E.; DeLaney, Thomas F.; Wang, Dian
2015-01-01
Purpose The purpose of this study was to evaluate the variability in target volume and organ at risk (OAR) contour delineation for retroperitoneal sarcoma (RPS) among 12 sarcoma radiation oncologists. Methods and Materials Radiation planning computed tomography (CT) scans for 2 cases of RPS were distributed among 12 sarcoma radiation oncologists with instructions for contouring gross tumor volume (GTV), clinical target volume (CTV), high-risk CTV (HR CTV: area judged to be at high risk of resulting in positive margins after resection), and OARs: bowel bag, small bowel, colon, stomach, and duodenum. Analysis of contour agreement was performed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results Ten radiation oncologists contoured both RPS cases, 1 contoured only RPS1, and 1 contoured only RPS2 such that each case was contoured by 11 radiation oncologists. The first case (RPS 1) was a patient with a de-differentiated (DD) liposarcoma (LPS) with a predominant well-differentiated (WD) component, and the second case (RPS 2) was a patient with DD LPS made up almost entirely of a DD component. Contouring agreement for GTV and CTV contours was high. However, the agreement for HR CTVs was only moderate. For OARs, agreement for stomach, bowel bag, small bowel, and colon was high, but agreement for duodenum (distorted by tumor in one of these cases) was fair to moderate. Conclusions For preoperative treatment of RPS, sarcoma radiation oncologists contoured GTV, CTV, and most OARs with a high level of agreement. HR CTV contours were more variable. Further clarification of this volume with the help of sarcoma surgical oncologists is necessary to reach consensus. More attention to delineation of the duodenum is also needed. PMID:26194680
Blind-Side, High-Temperature Fastener Lock
NASA Technical Reports Server (NTRS)
Matza, E. C.; While, D. M.
1985-01-01
Formed-in-place staple provides positive mechanical lock. Post-supported, advanced carbon/carbon standoff panels, currently under consideration as alternate thermal protection system for Shuttle orbiter, locking feature applicable to temperatures of 1,600 degrees F (870 degrees C) and higher and employable after panel installed, resulting in blind application. Blind-side locking technique employs wire staple inserted into grooves in post, formed in place by ramped portion of post grooves. This splays out wire ends that move into castellated end of grommet, mechanically locking post and grommet against relative rotation. Splayed ends provide mechanical lock to prevent wire from falling out.
Laser-assisted skin closure at 1.32 microns: the use of a software-driven medical laser system
NASA Astrophysics Data System (ADS)
Dew, Douglas K.; Hsu, Tung M.; Hsu, Long S.; Halpern, Steven J.; Michaels, Charles E.
1991-06-01
This study investigated the use of a computerized 1 .3 micron Nd:YAG laser to seal approximated wound edges in pig skin. The medical laser system used was the DLS Type 1 , 1 .32 micron Nd:YAG laser (Laser Surgery Software, Inc.). The purpose of this study was to evaluate the effectiveness of laser assisted skin closure using the DLS YAG laser in a large animal model. Effectiveness was judged on the basis of wound dehiscence, infection, unusual healing result and consistency of results. Comparative cosmetic result was also evaluated. In this study, the DLS YAG laser was used to close scalpel-induced, full-thickness wounds. The pig model was chosen for its many integumentary similarities to man. Controls included scalpel-induced wounds closed using suture, staple and some with norepair. After adequate anesthesia was achieved, the dorsum of Yucutan pigs (approximately 75- 100 pounds) each was clipped with animal hair clippers from the shoulder area to the hind legs. The area was then shaved with a razor blade, avoiding any inadvertent cuts or abrasions of the skin. The dorsum was divided into four rows of four parallel incisions made by a #15 scalpel blade. Full-thickness incisions, 9 cm long, were placed over the dorsum of the pigs and then closed either with one loosely approximating Prolene" suture (the "no repair' group), multiple interrupted 6-0 nylon sutures, staples or laser. The experimental tissue sealing group consisted of 1 69 laser assisted closures on 1 3 pigs. Sutured control wounds were closed with 6-0 nylon, full thickness, simple, interrupted sutures. Eight sutures were placed 1 cm apart along the 9 cm incision. Stapled control wounds were approximated using two evenly spaced 3-0 VicryP' sub-dermal sutures and the dermis closed using Proximate' skin staples. Eight staples were placed 1 cm apart along the 9 cm incision. The no-repair incisions were grossly approximated using a single 2-0 Prolene full thickness, simple, interrupted suture located at the center of the 9 cm incision. Experimental wounds were approximated using two evenly spaced subdermal 3.0 Vicryl' sutures and the dermis closed by laser sealing using the DLS YAG laser. Wounds were examined daily for the first seven days and followed for up to 20 months postoperatively. To facilitate wound edge approximation, surgical tape that is relatively transparent to 1.3 micron irradiation was used to hold the wound edges approximated while laser application occurred. Surgical tape was also applied to the "no-repair" suture and staple closures at the end of each procedure.
Power Control and Optimization of Photovoltaic and Wind Energy Conversion Systems
NASA Astrophysics Data System (ADS)
Ghaffari, Azad
Power map and Maximum Power Point (MPP) of Photovoltaic (PV) and Wind Energy Conversion Systems (WECS) highly depend on system dynamics and environmental parameters, e.g., solar irradiance, temperature, and wind speed. Power optimization algorithms for PV systems and WECS are collectively known as Maximum Power Point Tracking (MPPT) algorithm. Gradient-based Extremum Seeking (ES), as a non-model-based MPPT algorithm, governs the system to its peak point on the steepest descent curve regardless of changes of the system dynamics and variations of the environmental parameters. Since the power map shape defines the gradient vector, then a close estimate of the power map shape is needed to create user assignable transients in the MPPT algorithm. The Hessian gives a precise estimate of the power map in a neighborhood around the MPP. The estimate of the inverse of the Hessian in combination with the estimate of the gradient vector are the key parts to implement the Newton-based ES algorithm. Hence, we generate an estimate of the Hessian using our proposed perturbation matrix. Also, we introduce a dynamic estimator to calculate the inverse of the Hessian which is an essential part of our algorithm. We present various simulations and experiments on the micro-converter PV systems to verify the validity of our proposed algorithm. The ES scheme can also be used in combination with other control algorithms to achieve desired closed-loop performance. The WECS dynamics is slow which causes even slower response time for the MPPT based on the ES. Hence, we present a control scheme, extended from Field-Oriented Control (FOC), in combination with feedback linearization to reduce the convergence time of the closed-loop system. Furthermore, the nonlinear control prevents magnetic saturation of the stator of the Induction Generator (IG). The proposed control algorithm in combination with the ES guarantees the closed-loop system robustness with respect to high level parameter uncertainty in the IG dynamics. The simulation results verify the effectiveness of the proposed algorithm.
Load flow and state estimation algorithms for three-phase unbalanced power distribution systems
NASA Astrophysics Data System (ADS)
Madvesh, Chiranjeevi
Distribution load flow and state estimation are two important functions in distribution energy management systems (DEMS) and advanced distribution automation (ADA) systems. Distribution load flow analysis is a tool which helps to analyze the status of a power distribution system under steady-state operating conditions. In this research, an effective and comprehensive load flow algorithm is developed to extensively incorporate the distribution system components. Distribution system state estimation is a mathematical procedure which aims to estimate the operating states of a power distribution system by utilizing the information collected from available measurement devices in real-time. An efficient and computationally effective state estimation algorithm adapting the weighted-least-squares (WLS) method has been developed in this research. Both the developed algorithms are tested on different IEEE test-feeders and the results obtained are justified.
NASA Astrophysics Data System (ADS)
Xu, Shaoping; Zeng, Xiaoxia; Jiang, Yinnan; Tang, Yiling
2018-01-01
We proposed a noniterative principal component analysis (PCA)-based noise level estimation (NLE) algorithm that addresses the problem of estimating the noise level with a two-step scheme. First, we randomly extracted a number of raw patches from a given noisy image and took the smallest eigenvalue of the covariance matrix of the raw patches as the preliminary estimation of the noise level. Next, the final estimation was directly obtained with a nonlinear mapping (rectification) function that was trained on some representative noisy images corrupted with different known noise levels. Compared with the state-of-art NLE algorithms, the experiment results show that the proposed NLE algorithm can reliably infer the noise level and has robust performance over a wide range of image contents and noise levels, showing a good compromise between speed and accuracy in general.
Algorithm Estimates Microwave Water-Vapor Delay
NASA Technical Reports Server (NTRS)
Robinson, Steven E.
1989-01-01
Accuracy equals or exceeds conventional linear algorithms. "Profile" algorithm improved algorithm using water-vapor-radiometer data to produce estimates of microwave delays caused by water vapor in troposphere. Does not require site-specific and weather-dependent empirical parameters other than standard meteorological data, latitude, and altitude for use in conjunction with published standard atmospheric data. Basic premise of profile algorithm, wet-path delay approximated closely by solution to simplified version of nonlinear delay problem and generated numerically from each radiometer observation and simultaneous meteorological data.
Kalman Filters for Time Delay of Arrival-Based Source Localization
NASA Astrophysics Data System (ADS)
Klee, Ulrich; Gehrig, Tobias; McDonough, John
2006-12-01
In this work, we propose an algorithm for acoustic source localization based on time delay of arrival (TDOA) estimation. In earlier work by other authors, an initial closed-form approximation was first used to estimate the true position of the speaker followed by a Kalman filtering stage to smooth the time series of estimates. In the proposed algorithm, this closed-form approximation is eliminated by employing a Kalman filter to directly update the speaker's position estimate based on the observed TDOAs. In particular, the TDOAs comprise the observation associated with an extended Kalman filter whose state corresponds to the speaker's position. We tested our algorithm on a data set consisting of seminars held by actual speakers. Our experiments revealed that the proposed algorithm provides source localization accuracy superior to the standard spherical and linear intersection techniques. Moreover, the proposed algorithm, although relying on an iterative optimization scheme, proved efficient enough for real-time operation.
Motion Estimation Using the Firefly Algorithm in Ultrasonic Image Sequence of Soft Tissue
Chao, Chih-Feng; Horng, Ming-Huwi; Chen, Yu-Chan
2015-01-01
Ultrasonic image sequence of the soft tissue is widely used in disease diagnosis; however, the speckle noises usually influenced the image quality. These images usually have a low signal-to-noise ratio presentation. The phenomenon gives rise to traditional motion estimation algorithms that are not suitable to measure the motion vectors. In this paper, a new motion estimation algorithm is developed for assessing the velocity field of soft tissue in a sequence of ultrasonic B-mode images. The proposed iterative firefly algorithm (IFA) searches for few candidate points to obtain the optimal motion vector, and then compares it to the traditional iterative full search algorithm (IFSA) via a series of experiments of in vivo ultrasonic image sequences. The experimental results show that the IFA can assess the vector with better efficiency and almost equal estimation quality compared to the traditional IFSA method. PMID:25873987
Motion estimation using the firefly algorithm in ultrasonic image sequence of soft tissue.
Chao, Chih-Feng; Horng, Ming-Huwi; Chen, Yu-Chan
2015-01-01
Ultrasonic image sequence of the soft tissue is widely used in disease diagnosis; however, the speckle noises usually influenced the image quality. These images usually have a low signal-to-noise ratio presentation. The phenomenon gives rise to traditional motion estimation algorithms that are not suitable to measure the motion vectors. In this paper, a new motion estimation algorithm is developed for assessing the velocity field of soft tissue in a sequence of ultrasonic B-mode images. The proposed iterative firefly algorithm (IFA) searches for few candidate points to obtain the optimal motion vector, and then compares it to the traditional iterative full search algorithm (IFSA) via a series of experiments of in vivo ultrasonic image sequences. The experimental results show that the IFA can assess the vector with better efficiency and almost equal estimation quality compared to the traditional IFSA method.
Ultrasound Algorithm Derivation for Soil Moisture Content Estimation
NASA Technical Reports Server (NTRS)
Belisle, W.R.; Metzl, R.; Choi, J.; Aggarwal, M. D.; Coleman, T.
1997-01-01
Soil moisture content can be estimated by evaluating the velocity at which sound waves travel through a known volume of solid material. This research involved the development of three soil algorithms relating the moisture content to the velocity at which sound waves moved through dry and moist media. Pressure and shear wave propagation equations were used in conjunction with soil property descriptions to derive algorithms appropriate for describing the effects of moisture content variation on the velocity of sound waves in soils with and without complete soil pore water volumes, An elementary algorithm was used to estimate soil moisture contents ranging from 0.08 g/g to 0.5 g/g from sound wave velocities ranging from 526 m/s to 664 m/s. Secondary algorithms were also used to estimate soil moisture content from sound wave velocities through soils with pores that were filled predominantly with air or water.
Automatic Regionalization Algorithm for Distributed State Estimation in Power Systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Dexin; Yang, Liuqing; Florita, Anthony
The deregulation of the power system and the incorporation of generation from renewable energy sources recessitates faster state estimation in the smart grid. Distributed state estimation (DSE) has become a promising and scalable solution to this urgent demand. In this paper, we investigate the regionalization algorithms for the power system, a necessary step before distributed state estimation can be performed. To the best of the authors' knowledge, this is the first investigation on automatic regionalization (AR). We propose three spectral clustering based AR algorithms. Simulations show that our proposed algorithms outperform the two investigated manual regionalization cases. With the helpmore » of AR algorithms, we also show how the number of regions impacts the accuracy and convergence speed of the DSE and conclude that the number of regions needs to be chosen carefully to improve the convergence speed of DSEs.« less
Automatic Regionalization Algorithm for Distributed State Estimation in Power Systems: Preprint
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Dexin; Yang, Liuqing; Florita, Anthony
The deregulation of the power system and the incorporation of generation from renewable energy sources recessitates faster state estimation in the smart grid. Distributed state estimation (DSE) has become a promising and scalable solution to this urgent demand. In this paper, we investigate the regionalization algorithms for the power system, a necessary step before distributed state estimation can be performed. To the best of the authors' knowledge, this is the first investigation on automatic regionalization (AR). We propose three spectral clustering based AR algorithms. Simulations show that our proposed algorithms outperform the two investigated manual regionalization cases. With the helpmore » of AR algorithms, we also show how the number of regions impacts the accuracy and convergence speed of the DSE and conclude that the number of regions needs to be chosen carefully to improve the convergence speed of DSEs.« less
Joint Smoothed l₀-Norm DOA Estimation Algorithm for Multiple Measurement Vectors in MIMO Radar.
Liu, Jing; Zhou, Weidong; Juwono, Filbert H
2017-05-08
Direction-of-arrival (DOA) estimation is usually confronted with a multiple measurement vector (MMV) case. In this paper, a novel fast sparse DOA estimation algorithm, named the joint smoothed l 0 -norm algorithm, is proposed for multiple measurement vectors in multiple-input multiple-output (MIMO) radar. To eliminate the white or colored Gaussian noises, the new method first obtains a low-complexity high-order cumulants based data matrix. Then, the proposed algorithm designs a joint smoothed function tailored for the MMV case, based on which joint smoothed l 0 -norm sparse representation framework is constructed. Finally, for the MMV-based joint smoothed function, the corresponding gradient-based sparse signal reconstruction is designed, thus the DOA estimation can be achieved. The proposed method is a fast sparse representation algorithm, which can solve the MMV problem and perform well for both white and colored Gaussian noises. The proposed joint algorithm is about two orders of magnitude faster than the l 1 -norm minimization based methods, such as l 1 -SVD (singular value decomposition), RV (real-valued) l 1 -SVD and RV l 1 -SRACV (sparse representation array covariance vectors), and achieves better DOA estimation performance.
Wang, Jun; Zhou, Bihua; Zhou, Shudao
2016-01-01
This paper proposes an improved cuckoo search (ICS) algorithm to establish the parameters of chaotic systems. In order to improve the optimization capability of the basic cuckoo search (CS) algorithm, the orthogonal design and simulated annealing operation are incorporated in the CS algorithm to enhance the exploitation search ability. Then the proposed algorithm is used to establish parameters of the Lorenz chaotic system and Chen chaotic system under the noiseless and noise condition, respectively. The numerical results demonstrate that the algorithm can estimate parameters with high accuracy and reliability. Finally, the results are compared with the CS algorithm, genetic algorithm, and particle swarm optimization algorithm, and the compared results demonstrate the method is energy-efficient and superior. PMID:26880874
Metabolic flux estimation using particle swarm optimization with penalty function.
Long, Hai-Xia; Xu, Wen-Bo; Sun, Jun
2009-01-01
Metabolic flux estimation through 13C trace experiment is crucial for quantifying the intracellular metabolic fluxes. In fact, it corresponds to a constrained optimization problem that minimizes a weighted distance between measured and simulated results. In this paper, we propose particle swarm optimization (PSO) with penalty function to solve 13C-based metabolic flux estimation problem. The stoichiometric constraints are transformed to an unconstrained one, by penalizing the constraints and building a single objective function, which in turn is minimized using PSO algorithm for flux quantification. The proposed algorithm is applied to estimate the central metabolic fluxes of Corynebacterium glutamicum. From simulation results, it is shown that the proposed algorithm has superior performance and fast convergence ability when compared to other existing algorithms.
Parallel, stochastic measurement of molecular surface area.
Juba, Derek; Varshney, Amitabh
2008-08-01
Biochemists often wish to compute surface areas of proteins. A variety of algorithms have been developed for this task, but they are designed for traditional single-processor architectures. The current trend in computer hardware is towards increasingly parallel architectures for which these algorithms are not well suited. We describe a parallel, stochastic algorithm for molecular surface area computation that maps well to the emerging multi-core architectures. Our algorithm is also progressive, providing a rough estimate of surface area immediately and refining this estimate as time goes on. Furthermore, the algorithm generates points on the molecular surface which can be used for point-based rendering. We demonstrate a GPU implementation of our algorithm and show that it compares favorably with several existing molecular surface computation programs, giving fast estimates of the molecular surface area with good accuracy.
Channel estimation based on quantized MMP for FDD massive MIMO downlink
NASA Astrophysics Data System (ADS)
Guo, Yao-ting; Wang, Bing-he; Qu, Yi; Cai, Hua-jie
2016-10-01
In this paper, we consider channel estimation for Massive MIMO systems operating in frequency division duplexing mode. By exploiting the sparsity of propagation paths in Massive MIMO channel, we develop a compressed sensing(CS) based channel estimator which can reduce the pilot overhead. As compared with the conventional least squares (LS) and linear minimum mean square error(LMMSE) estimation, the proposed algorithm is based on the quantized multipath matching pursuit - MMP - reduced the pilot overhead and performs better than other CS algorithms. The simulation results demonstrate the advantage of the proposed algorithm over various existing methods including the LS, LMMSE, CoSaMP and conventional MMP estimators.
NASA Astrophysics Data System (ADS)
Cua, G.; Fischer, M.; Heaton, T.; Wiemer, S.
2009-04-01
The Virtual Seismologist (VS) algorithm is a Bayesian approach to regional, network-based earthquake early warning (EEW). Bayes' theorem as applied in the VS algorithm states that the most probable source estimates at any given time is a combination of contributions from relatively static prior information that does not change over the timescale of earthquake rupture and a likelihood function that evolves with time to take into account incoming pick and amplitude observations from the on-going earthquake. Potentially useful types of prior information include network topology or station health status, regional hazard maps, earthquake forecasts, and the Gutenberg-Richter magnitude-frequency relationship. The VS codes provide magnitude and location estimates once picks are available at 4 stations; these source estimates are subsequently updated each second. The algorithm predicts the geographical distribution of peak ground acceleration and velocity using the estimated magnitude and location and appropriate ground motion prediction equations; the peak ground motion estimates are also updated each second. Implementation of the VS algorithm in California and Switzerland is funded by the Seismic Early Warning for Europe (SAFER) project. The VS method is one of three EEW algorithms whose real-time performance is being evaluated and tested by the California Integrated Seismic Network (CISN) EEW project. A crucial component of operational EEW algorithms is the ability to distinguish between noise and earthquake-related signals in real-time. We discuss various empirical approaches that allow the VS algorithm to operate in the presence of noise. Real-time operation of the VS codes at the Southern California Seismic Network (SCSN) began in July 2008. On average, the VS algorithm provides initial magnitude, location, origin time, and ground motion distribution estimates within 17 seconds of the earthquake origin time. These initial estimate times are dominated by the time for 4 acceptable picks to be available, and thus are heavily influenced by the station density in a given region; these initial estimate times also include the effects of telemetry delay, which ranges between 6 and 15 seconds at the SCSN, and processing time (~1 second). Other relevant performance statistics include: 95% of initial real-time location estimates are within 20 km of the actual epicenter, 97% of initial real-time magnitude estimates are within one magnitude unit of the network magnitude. Extension of real-time VS operations to networks in Northern California is an on-going effort. In Switzerland, the VS codes have been run on offline waveform data from over 125 earthquakes recorded by the Swiss Digital Seismic Network (SDSN) and the Swiss Strong Motion Network (SSMS). We discuss the performance of the VS algorithm on these datasets in terms of magnitude, location, and ground motion estimation.
Thompson, Frances E; Midthune, Douglas; Kahle, Lisa; Dodd, Kevin W
2017-06-01
Background: Methods for improving the utility of short dietary assessment instruments are needed. Objective: We sought to describe the development of the NHANES Dietary Screener Questionnaire (DSQ) and its scoring algorithms and performance. Methods: The 19-item DSQ assesses intakes of fruits and vegetables, whole grains, added sugars, dairy, fiber, and calcium. Two nonconsecutive 24-h dietary recalls and the DSQ were administered in NHANES 2009-2010 to respondents aged 2-69 y ( n = 7588). The DSQ frequency responses, coupled with sex- and age-specific portion size information, were regressed on intake from 24-h recalls by using the National Cancer Institute usual intake method to obtain scoring algorithms to estimate mean and prevalences of reaching 2 a priori threshold levels. The resulting scoring algorithms were applied to the DSQ and compared with intakes estimated with the 24-h recall data only. The stability of the derived scoring algorithms was evaluated in repeated sampling. Finally, scoring algorithms were applied to screener data, and these estimates were compared with those from multiple 24-h recalls in 3 external studies. Results: The DSQ and its scoring algorithms produced estimates of mean intake and prevalence that agreed closely with those from multiple 24-h recalls. The scoring algorithms were stable in repeated sampling. Differences in the means were <2%; differences in prevalence were <16%. In other studies, agreement between screener and 24-h recall estimates in fruit and vegetable intake varied. For example, among men in 2 studies, estimates from the screener were significantly lower than the 24-h recall estimates (3.2 compared with 3.8 and 3.2 compared with 4.1). In the third study, agreement between the screener and 24-h recall estimates were close among both men (3.2 compared with 3.1) and women (2.6 compared with 2.5). Conclusions: This approach to developing scoring algorithms is an advance in the use of screeners. However, because these algorithms may not be generalizable to all studies, a pilot study in the proposed study population is advisable. Although more precise instruments such as 24-h dietary recalls are recommended in most research, the NHANES DSQ provides a less burdensome alternative when time and resources are constrained and interest is in a limited set of dietary factors. © 2017 American Society for Nutrition.
Jung, Jaehoon; Yoon, Inhye; Paik, Joonki
2016-01-01
This paper presents an object occlusion detection algorithm using object depth information that is estimated by automatic camera calibration. The object occlusion problem is a major factor to degrade the performance of object tracking and recognition. To detect an object occlusion, the proposed algorithm consists of three steps: (i) automatic camera calibration using both moving objects and a background structure; (ii) object depth estimation; and (iii) detection of occluded regions. The proposed algorithm estimates the depth of the object without extra sensors but with a generic red, green and blue (RGB) camera. As a result, the proposed algorithm can be applied to improve the performance of object tracking and object recognition algorithms for video surveillance systems. PMID:27347978
A hardware-oriented concurrent TZ search algorithm for High-Efficiency Video Coding
NASA Astrophysics Data System (ADS)
Doan, Nghia; Kim, Tae Sung; Rhee, Chae Eun; Lee, Hyuk-Jae
2017-12-01
High-Efficiency Video Coding (HEVC) is the latest video coding standard, in which the compression performance is double that of its predecessor, the H.264/AVC standard, while the video quality remains unchanged. In HEVC, the test zone (TZ) search algorithm is widely used for integer motion estimation because it effectively searches the good-quality motion vector with a relatively small amount of computation. However, the complex computation structure of the TZ search algorithm makes it difficult to implement it in the hardware. This paper proposes a new integer motion estimation algorithm which is designed for hardware execution by modifying the conventional TZ search to allow parallel motion estimations of all prediction unit (PU) partitions. The algorithm consists of the three phases of zonal, raster, and refinement searches. At the beginning of each phase, the algorithm obtains the search points required by the original TZ search for all PU partitions in a coding unit (CU). Then, all redundant search points are removed prior to the estimation of the motion costs, and the best search points are then selected for all PUs. Compared to the conventional TZ search algorithm, experimental results show that the proposed algorithm significantly decreases the Bjøntegaard Delta bitrate (BD-BR) by 0.84%, and it also reduces the computational complexity by 54.54%.
An algorithmic approach to crustal deformation analysis
NASA Technical Reports Server (NTRS)
Iz, Huseyin Baki
1987-01-01
In recent years the analysis of crustal deformation measurements has become important as a result of current improvements in geodetic methods and an increasing amount of theoretical and observational data provided by several earth sciences. A first-generation data analysis algorithm which combines a priori information with current geodetic measurements was proposed. Relevant methods which can be used in the algorithm were discussed. Prior information is the unifying feature of this algorithm. Some of the problems which may arise through the use of a priori information in the analysis were indicated and preventive measures were demonstrated. The first step in the algorithm is the optimal design of deformation networks. The second step in the algorithm identifies the descriptive model of the deformation field. The final step in the algorithm is the improved estimation of deformation parameters. Although deformation parameters are estimated in the process of model discrimination, they can further be improved by the use of a priori information about them. According to the proposed algorithm this information must first be tested against the estimates calculated using the sample data only. Null-hypothesis testing procedures were developed for this purpose. Six different estimators which employ a priori information were examined. Emphasis was put on the case when the prior information is wrong and analytical expressions for possible improvements under incompatible prior information were derived.
Jha, Abhinav K.; Kupinski, Matthew A.; Rodríguez, Jeffrey J.; Stephen, Renu M.; Stopeck, Alison T.
2012-01-01
In many studies, the estimation of the apparent diffusion coefficient (ADC) of lesions in visceral organs in diffusion-weighted (DW) magnetic resonance images requires an accurate lesion-segmentation algorithm. To evaluate these lesion-segmentation algorithms, region-overlap measures are used currently. However, the end task from the DW images is accurate ADC estimation, and the region-overlap measures do not evaluate the segmentation algorithms on this task. Moreover, these measures rely on the existence of gold-standard segmentation of the lesion, which is typically unavailable. In this paper, we study the problem of task-based evaluation of segmentation algorithms in DW imaging in the absence of a gold standard. We first show that using manual segmentations instead of gold-standard segmentations for this task-based evaluation is unreliable. We then propose a method to compare the segmentation algorithms that does not require gold-standard or manual segmentation results. The no-gold-standard method estimates the bias and the variance of the error between the true ADC values and the ADC values estimated using the automated segmentation algorithm. The method can be used to rank the segmentation algorithms on the basis of both accuracy and precision. We also propose consistency checks for this evaluation technique. PMID:22713231
Sensitivity of NTCP parameter values against a change of dose calculation algorithm.
Brink, Carsten; Berg, Martin; Nielsen, Morten
2007-09-01
Optimization of radiation treatment planning requires estimations of the normal tissue complication probability (NTCP). A number of models exist that estimate NTCP from a calculated dose distribution. Since different dose calculation algorithms use different approximations the dose distributions predicted for a given treatment will in general depend on the algorithm. The purpose of this work is to test whether the optimal NTCP parameter values change significantly when the dose calculation algorithm is changed. The treatment plans for 17 breast cancer patients have retrospectively been recalculated with a collapsed cone algorithm (CC) to compare the NTCP estimates for radiation pneumonitis with those obtained from the clinically used pencil beam algorithm (PB). For the PB calculations the NTCP parameters were taken from previously published values for three different models. For the CC calculations the parameters were fitted to give the same NTCP as for the PB calculations. This paper demonstrates that significant shifts of the NTCP parameter values are observed for three models, comparable in magnitude to the uncertainties of the published parameter values. Thus, it is important to quote the applied dose calculation algorithm when reporting estimates of NTCP parameters in order to ensure correct use of the models.
Sensitivity of NTCP parameter values against a change of dose calculation algorithm
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brink, Carsten; Berg, Martin; Nielsen, Morten
2007-09-15
Optimization of radiation treatment planning requires estimations of the normal tissue complication probability (NTCP). A number of models exist that estimate NTCP from a calculated dose distribution. Since different dose calculation algorithms use different approximations the dose distributions predicted for a given treatment will in general depend on the algorithm. The purpose of this work is to test whether the optimal NTCP parameter values change significantly when the dose calculation algorithm is changed. The treatment plans for 17 breast cancer patients have retrospectively been recalculated with a collapsed cone algorithm (CC) to compare the NTCP estimates for radiation pneumonitis withmore » those obtained from the clinically used pencil beam algorithm (PB). For the PB calculations the NTCP parameters were taken from previously published values for three different models. For the CC calculations the parameters were fitted to give the same NTCP as for the PB calculations. This paper demonstrates that significant shifts of the NTCP parameter values are observed for three models, comparable in magnitude to the uncertainties of the published parameter values. Thus, it is important to quote the applied dose calculation algorithm when reporting estimates of NTCP parameters in order to ensure correct use of the models.« less
Chekan, Edward; Whelan, Richard L
2014-01-01
The introduction of both new surgical devices and reengineered existing devices leads to modifications in the way traditional tasks are carried out and allows for the development of new surgical techniques. Each new device has benefits and limitations in regards to tissue interactions that, if known, allow for optimal use. However, most surgeons are unaware of these attributes and, therefore, new device introduction creates a "knowledge gap" that is potentially dangerous. The goal of this review is to present a framework for the study of device- tissue interactions and to initiate the process of "filling in" the knowledge gap via the available literature. Surgical staplers, which are continually being developed, are the focus of this piece. The integrity of the staple line, which depends on adequate tissue compression, is the primary factor in creating a stable anastomosis. This review focuses on published studies that evaluated the creation of stable anastomoses in bariatric, thoracic, and colorectal procedures. Understanding how staplers interact with target tissues is key to improving patient outcomes. It is clear from this review that each tissue type presents unique challenges. The thickness of each tissue varies as do the intrinsic biomechanical properties that determine the ideal compressive force and prefiring compression time for each tissue type. The correct staple height will vary depending on these tissue-specific properties and the tissue pathology. These studies reinforce the universal theme that compression, staple height, tissue thickness, tissue compressibility, and tissue type must all be considered by the surgeon prior to choosing a stapler and cartridge. The surgeon's experience, therefore, is a critical factor. Educational programs need to be established to inform and update surgeons on the characteristics of each stapler. It is hoped that the framework presented in this review will facilitate this process.
Lin, H-C; Ren, D-L; He, Q-L; Peng, H; Xie, S-K; Su, D; Wang, X-X
2012-10-01
Circular stapled hemorrhoidopexy (CSH) is an effective technique for treating prolapsing hemorrhoids; but urgency and anal stenosis are common postoperative complications. The aim of this study was to assess the efficacy and postoperative outcomes of partial stapled hemorrhoidopexy (PSH), compared with CSH. Seventy-two consecutive patients with grade III and IV hemorrhoids who met the inclusion/exclusion criteria were divided in a non-randomized manner to undergo either PSH (n = 34) or CSH (n = 38). Intraoperative and postoperative parameters in both groups were collected and compared. The postoperative visual analog score for pain at first defecation was significantly lower in the PSH group than that in the CSH group (P = 0.001). Fewer patients in the PSH group experienced postoperative urgency, compared with those in the CSH group at 12 h, 1 day, and 7 days after surgery (P = 0.025, P = 0.019, and P = 0.043, respectively). Gas incontinence occurred in 3 patients (7.9%) in the CSH group, but in none of patients in the PSH group (P = 0.242). Postoperative anal stenosis developed in one patient (2.6%) in the CSH group, but in none of the patients in the PSH group (P = 1.0). The 2-year recurrence rate was 2.9 and 5.3%, respectively, in the PSH and CSH groups (P = 1.0). The 2-year recurrence rate is similar in patients with grade III-IV hemorrhoids treated with PSH or CSH. However, PSH is associated with less postoperative pain, fewer episodes of urgency, and no anal incontinence or anal stenosis.
Gill, Amreeta; Shellock, Frank G
2012-01-09
Metallic skin closure staples and vessel ligation clips should be tested at 3-Tesla to characterize MRI issues in order to ensure patient safety. Therefore, metallic surgical implants were assessed at 3-Tesla for magnetic field interactions, MRI-related heating, and artifacts. A skin closure staple (Visistat Skin Stapler, staple, Polytetrafluoroethylene, PTFE, coated 316L/316LVM stainless steel; Teleflex Medical, Durham, NC) and a vessel ligation clip (Hemoclip Traditional, stainless steel; Teleflex Medical, Durham, NC) that represented the largest metallic sizes made from materials with the highest magnetic susceptibilities (i.e., based on material information) among 61 other surgical implants (52 metallic implants, 9 nonmetallic implants) underwent evaluation for magnetic field interactions, MRI-related heating, and artifacts using standardized techniques. MRI-related heating was assessed by placing each implant in a gelled-saline-filled phantom with MRI performed using a transmit/receive RF body coil at an MR system reported, whole body averaged SAR of 2.9-W/kg for 15-min. Artifacts were characterized using T1-weighted, SE and GRE pulse sequences. Each surgical implant showed minor magnetic field interactions (20- and 27-degrees, which is acceptable from a safety consideration). Heating was not substantial (highest temperature change, ≤ 1.6°C). Artifacts may create issues if the area of interest is in the same area or close to the respective surgical implant. The results demonstrated that it would be acceptable for patients with these metallic surgical implants to undergo MRI at 3-Tesla or less. Because of the materials and dimensions of the surgical implants that underwent testing, these findings pertain to 61 additional similar implants.
Spector, David; Perry, Zvi; Konobeck, Tracy; Mooradian, Daniel; Shikora, Scott
2011-04-01
The use of staplers in gastrointestinal surgery is widespread, especially in advanced laparoscopic procedures. Staple line reinforcement with a buttress reduces bleeding and associated complications through a combination of factors. The intrinsic hemostatic properties of buttress materials have not been examined. This study examined the intrinsic hemostatic properties of two different types of material used in buttressing in an accepted hemostasis model that does not involve stapling or its effects by compression. An acellular collagen buttress (Veritas) and a synthetic polymer buttress (Duet) were compared to two commonly used hemostatic agents, Syvek and Surgicel, with gauze as control. In a swine capsular stripping hemostasis model, a 1 × 1 cm section of spleen capsule was removed and used as a source of bleeding, with one patch of material tested per bleeding site. A total of 51 wounds were created in five pigs (each patch n = 10, control n = 11). Hemostatic efficacy was assessed by quantitating the number of applications and total time needed for bleeding to stop. The mean time needed for hemostasis for Syvek and Veritas patches was significantly less than gauze, Duet and Surgicel (4.02, 4.51 vs. 8.97, 9.22, and 10.30 min respectively; p < 0.05). The Syvek and Veritas patches required significantly fewer applications than gauze, Duet™ and Surgicel (1.7, 2.2 vs. 4.1, 4.6, and 4.9 respectively; p < 0.01). The intrinsic hemostatic properties of different buttressing materials vary widely. In this study, a collagen buttress was significantly better at promoting hemostasis than the synthetic buttress material in a nonstapling model. This could be another factor to consider when choosing a buttress for staple line reinforcement.
Kim, Hye Jin; Choi, Gyu-Seog; Park, Jun Seok; Park, Soo Yeun
2013-01-01
Recently, a single-stapled technique (SST) was performed instead of the conventional double-stapled technique (DST) in laparoscopic low anterior resection for anastomosis, by placement of intracorporeal purse-string sutures on the distal rectum with transanal specimen extraction. This study aimed to compare the short-term outcomes between the two anastomotic techniques. Between July 2007 and April 2010, 60 patients underwent SST by laparoscopic or robotic procedure. These patients were matched 1:2 by age, gender, date of surgery, and tumor stage with 120 patients who underwent conventional DST in laparoscopic low anterior resection. The robotic-assisted operative approach was used more frequently in the SST group than in the DST group (61.7 % vs. 3.3 %, p < 0.001). The mean operative time was 203.9 (range, 120-400) min for the SST group and 167.6 (range, 90-300) min for the DST group (p < 0.001). For specimen removal, the transanal approach was used in the SST group, while the transabdominal approach was used for the DST group. The pain score (visual analogue scale) of the SST group was lower (4.5 vs. 5.6, p < 0.001), although postoperative recovery was similar. Pathological examination revealed that the distal resection margin was significantly longer in the SST group (3.1 vs. 2.5 cm, p = 0.018). Postoperative morbidity including anastomotic leakage was similar in both groups. SST yielded equivalent short-term outcomes when compared to conventional DST and provided the advantages of minimal access and a longer distal resection margin. Therefore, SST in lower anterior resection may be a useful alternative to conventional DST.
2012-01-01
Purpose Metallic skin closure staples and vessel ligation clips should be tested at 3-Tesla to characterize MRI issues in order to ensure patient safety. Therefore, metallic surgical implants were assessed at 3-Tesla for magnetic field interactions, MRI-related heating, and artifacts. Methods A skin closure staple (Visistat Skin Stapler, staple, Polytetrafluoroethylene, PTFE, coated 316L/316LVM stainless steel; Teleflex Medical, Durham, NC) and a vessel ligation clip (Hemoclip Traditional, stainless steel; Teleflex Medical, Durham, NC) that represented the largest metallic sizes made from materials with the highest magnetic susceptibilities (i.e., based on material information) among 61 other surgical implants (52 metallic implants, 9 nonmetallic implants) underwent evaluation for magnetic field interactions, MRI-related heating, and artifacts using standardized techniques. MRI-related heating was assessed by placing each implant in a gelled-saline-filled phantom with MRI performed using a transmit/receive RF body coil at an MR system reported, whole body averaged SAR of 2.9-W/kg for 15-min. Artifacts were characterized using T1-weighted, SE and GRE pulse sequences. Results Each surgical implant showed minor magnetic field interactions (20- and 27-degrees, which is acceptable from a safety consideration). Heating was not substantial (highest temperature change, ≤ 1.6°C). Artifacts may create issues if the area of interest is in the same area or close to the respective surgical implant. Conclusions The results demonstrated that it would be acceptable for patients with these metallic surgical implants to undergo MRI at 3-Tesla or less. Because of the materials and dimensions of the surgical implants that underwent testing, these findings pertain to 61 additional similar implants. PMID:22230200
García-Granero, Eduardo; Navarro, Francisco; Cerdán Santacruz, Carlos; Frasson, Matteo; García-Granero, Alvaro; Marinello, Franco; Flor-Lorente, Blas; Espí, Alejandro
2017-11-01
Our aim was to assess whether the individual surgeon is an independent risk factor for anastomotic leak in double-stapled colorectal anastomosis after left colon and rectal cancer resection. This retrospective analysis of a prospectively collected database consists of a consecutive series of 800 patients who underwent an elective left colon and rectal resection with a colorectal, double-stapled anastomosis between 1993 and 2009 in a specialized colorectal unit of a tertiary hospital with 7 participating surgeons. The main outcome variable was anastomotic leak, defined as leak of luminal contents from a colorectal anastomosis between 2 hollow viscera diagnosed radiologically, clinically, endoscopically, or intraoperatively. Pelvic abscesses were also considered to be an anastomotic leak. Radiologic examination was performed when there was clinical suspicion of leak. Anastomotic leak occurred in 6.1% of patients, of which 33 (67%) were treated operatively, 6 (12%) with radiologic drains, and 10 (21%) by medical treatment. Postoperative mortality rate was 2.9% for the whole group of 800 patients. In patients with anastomotic leak, mortality rate increased up to 16% vs 2.0% in patients without anastomotic leak (P < .0001). At multivariate analysis, rectal location of tumor, male sex, bowel obstruction preoperatively, tobacco use, diabetes, perioperative transfusion, and the individual surgeon were independent risk factors for anastomotic leak. The surgeon was the most important factor (mean odds ratio 4.9; range 1.0 to 13.5). The variance of anastomotic leak between the different surgeons was 0.56 in the logit scale. The individual surgeon is an independent risk factor for leakage in double-stapled, colorectal, end-to-end anastomosis after oncologic left-sided colorectal resection. Copyright © 2017 Elsevier Inc. All rights reserved.
Kravchick, Sergey; Lobik, Leonid; Paz, Adrian; Stepnov, Eugeny; Ben-Dor, David; Cytron, Shmuel
2013-01-01
We retrospectively assessed our experience with the W-shaped orthotopic ileal pouch, which was constructed with non-absorbable titanium staples. For these purpose, we discuss the results of bladder capacity, urinary continence and early and long-term postoperative complications. We included in the study 17 patients who underwent radical cystoprostatectomy followed by construction of an orthotopic W-shaped ileal pouch between October 2000 and November 2009. A 65-70 cm segment of ileum was isolated and prearranged into a W-configuration, leaving two 10 cm intact segments on both sides of the ileal fragment. In our technique we entirely anatomized all adjacent limbs in order to create a sphere-shaped pouch. The ureters were directly anastomized to both intact segments of the ileal division. All our patients underwent pouchscopy 6 months after operation and annually. Mean operative time for neobladder reconstruction and ureteral anastomoses was 87 ± 7.67 minutes. In one patient a leak from the ileo-ileal anastomosis was confirmed on the 3rd day after operation. In 2 cases unilateral stricture of the ureteral-neobladder anastomosis was documented. Staple lines were mostly covered with ileal mucosa after 6 months. The mean functional bladder capacity was 340 ± 27.6 mL and 375 ± 43.4 mL at 6 and 12 months, respectively. First-year daytime and nighttime continence was good and acceptable in 90% and 78% of patients, while it increased to 95% during the 2nd year. The long term follow-up shows that non-absorbable titanium staples can be safely used for creation of an orthotopic ileal neobladder. However, these data should be further validated in a larger series of patients.
A Randomized Trial Comparing Stapled Rectal Mucosectomy Versus Open and Semiclosed Hemorrhoidectomy.
Ripetti, Valter; La Vaccara, Vincenzo; Greco, Santi; Arullani, Augusto
2015-11-01
Different results have been reported concerning the postoperative outcomes of different surgical approaches for hemorrhoids. We aimed to determine the postoperative outcome following 3 main surgical techniques. A prospective, randomized trial was designed with 180 patients in 3 arms of 60 patients each. The study was conducted from April 1999 to January 2007 at the University Hospital "Campus Bio-Medico di Roma." All of the patients who were referred for hemorrhoid surgery were enrolled according to inclusion and exclusion criteria (ISRCTN12040297). Treatments according to the open, semiclosed, and stapled techniques were compared. Sample size was calculated to determine a difference in terms of the intensity of postoperative pain at the first week and the days required for return to work activity. After 1 week, patients who underwent semiclosed hemorrhoidectomy reported significantly less pain (p < 0.01) and a significant decrease in analgesic intake from the third postoperative day (p < 0.01) than after the other 2 techniques. The patients resumed work ≈11 days after semiclosed and stapled techniques (11.8 and 11.6 days), which was earlier compared with 21.3 days in the open group (p < 0.05). The high number of patients excluded might be considered a limitation of the study, but our selection criteria including patients living within 50 km of the hospital allowed for a low rate (9.4%) of patients lost to follow-up. This study found an earlier resumption of work and less pain in patients who underwent the stapled and semiclosed procedures rather than open, which was associated with more complications, particularly because of a higher rate of stenosis (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A196).
NASA Astrophysics Data System (ADS)
Asgari, Shadnaz; Ali, Andreas M.; Collier, Travis C.; Yao, Yuan; Hudson, Ralph E.; Yao, Kung; Taylor, Charles E.
2007-09-01
The focus of most direction-of-arrival (DOA) estimation problems has been based mainly on a two-dimensional (2D) scenario where we only need to estimate the azimuth angle. But in various practical situations we have to deal with a three-dimensional scenario. The importance of being able to estimate both azimuth and elevation angles with high accuracy and low complexity is of interest. We present the theoretical and the practical issues of DOA estimation using the Approximate-Maximum-Likelihood (AML) algorithm in a 3D scenario. We show that the performance of the proposed 3D AML algorithm converges to the Cramer-Rao Bound. We use the concept of an isotropic array to reduce the complexity of the proposed algorithm by advocating a decoupled 3D version. We also explore a modified version of the decoupled 3D AML algorithm which can be used for DOA estimation with non-isotropic arrays. Various numerical results are presented. We use two acoustic arrays each consisting of 8 microphones to do some field measurements. The processing of the measured data from the acoustic arrays for different azimuth and elevation angles confirms the effectiveness of the proposed methods.
IEEE 802.15.4 ZigBee-Based Time-of-Arrival Estimation for Wireless Sensor Networks.
Cheon, Jeonghyeon; Hwang, Hyunsu; Kim, Dongsun; Jung, Yunho
2016-02-05
Precise time-of-arrival (TOA) estimation is one of the most important techniques in RF-based positioning systems that use wireless sensor networks (WSNs). Because the accuracy of TOA estimation is proportional to the RF signal bandwidth, using broad bandwidth is the most fundamental approach for achieving higher accuracy. Hence, ultra-wide-band (UWB) systems with a bandwidth of 500 MHz are commonly used. However, wireless systems with broad bandwidth suffer from the disadvantages of high complexity and high power consumption. Therefore, it is difficult to employ such systems in various WSN applications. In this paper, we present a precise time-of-arrival (TOA) estimation algorithm using an IEEE 802.15.4 ZigBee system with a narrow bandwidth of 2 MHz. In order to overcome the lack of bandwidth, the proposed algorithm estimates the fractional TOA within the sampling interval. Simulation results show that the proposed TOA estimation algorithm provides an accuracy of 0.5 m at a signal-to-noise ratio (SNR) of 8 dB and achieves an SNR gain of 5 dB as compared with the existing algorithm. In addition, experimental results indicate that the proposed algorithm provides accurate TOA estimation in a real indoor environment.
Schoenberg, Mike R; Lange, Rael T; Saklofske, Donald H; Suarez, Mariann; Brickell, Tracey A
2008-12-01
Determination of neuropsychological impairment involves contrasting obtained performances with a comparison standard, which is often an estimate of premorbid IQ. M. R. Schoenberg, R. T. Lange, T. A. Brickell, and D. H. Saklofske (2007) proposed the Child Premorbid Intelligence Estimate (CPIE) to predict premorbid Full Scale IQ (FSIQ) using the Wechsler Intelligence Scale for Children-4th Edition (WISC-IV; Wechsler, 2003). The CPIE includes 12 algorithms to predict FSIQ, 1 using demographic variables and 11 algorithms combining WISC-IV subtest raw scores with demographic variables. The CPIE was applied to a sample of children with acquired traumatic brain injury (TBI sample; n = 40) and a healthy demographically matched sample (n = 40). Paired-samples t tests found estimated premorbid FSIQ differed from obtained FSIQ when applied to the TBI sample (ps
Experimental verification of an interpolation algorithm for improved estimates of animal position
NASA Astrophysics Data System (ADS)
Schell, Chad; Jaffe, Jules S.
2004-07-01
This article presents experimental verification of an interpolation algorithm that was previously proposed in Jaffe [J. Acoust. Soc. Am. 105, 3168-3175 (1999)]. The goal of the algorithm is to improve estimates of both target position and target strength by minimizing a least-squares residual between noise-corrupted target measurement data and the output of a model of the sonar's amplitude response to a target at a set of known locations. Although this positional estimator was shown to be a maximum likelihood estimator, in principle, experimental verification was desired because of interest in understanding its true performance. Here, the accuracy of the algorithm is investigated by analyzing the correspondence between a target's true position and the algorithm's estimate. True target position was measured by precise translation of a small test target (bead) or from the analysis of images of fish from a coregistered optical imaging system. Results with the stationary spherical test bead in a high signal-to-noise environment indicate that a large increase in resolution is possible, while results with commercial aquarium fish indicate a smaller increase is obtainable. However, in both experiments the algorithm provides improved estimates of target position over those obtained by simply accepting the angular positions of the sonar beam with maximum output as target position. In addition, increased accuracy in target strength estimation is possible by considering the effects of the sonar beam patterns relative to the interpolated position. A benefit of the algorithm is that it can be applied ``ex post facto'' to existing data sets from commercial multibeam sonar systems when only the beam intensities have been stored after suitable calibration.
Chen, Jie; Li, Jiahong; Yang, Shuanghua; Deng, Fang
2017-11-01
The identification of the nonlinearity and coupling is crucial in nonlinear target tracking problem in collaborative sensor networks. According to the adaptive Kalman filtering (KF) method, the nonlinearity and coupling can be regarded as the model noise covariance, and estimated by minimizing the innovation or residual errors of the states. However, the method requires large time window of data to achieve reliable covariance measurement, making it impractical for nonlinear systems which are rapidly changing. To deal with the problem, a weighted optimization-based distributed KF algorithm (WODKF) is proposed in this paper. The algorithm enlarges the data size of each sensor by the received measurements and state estimates from its connected sensors instead of the time window. A new cost function is set as the weighted sum of the bias and oscillation of the state to estimate the "best" estimate of the model noise covariance. The bias and oscillation of the state of each sensor are estimated by polynomial fitting a time window of state estimates and measurements of the sensor and its neighbors weighted by the measurement noise covariance. The best estimate of the model noise covariance is computed by minimizing the weighted cost function using the exhaustive method. The sensor selection method is in addition to the algorithm to decrease the computation load of the filter and increase the scalability of the sensor network. The existence, suboptimality and stability analysis of the algorithm are given. The local probability data association method is used in the proposed algorithm for the multitarget tracking case. The algorithm is demonstrated in simulations on tracking examples for a random signal, one nonlinear target, and four nonlinear targets. Results show the feasibility and superiority of WODKF against other filtering algorithms for a large class of systems.
Wearable Sensor Localization Considering Mixed Distributed Sources in Health Monitoring Systems
Wan, Liangtian; Han, Guangjie; Wang, Hao; Shu, Lei; Feng, Nanxing; Peng, Bao
2016-01-01
In health monitoring systems, the base station (BS) and the wearable sensors communicate with each other to construct a virtual multiple input and multiple output (VMIMO) system. In real applications, the signal that the BS received is a distributed source because of the scattering, reflection, diffraction and refraction in the propagation path. In this paper, a 2D direction-of-arrival (DOA) estimation algorithm for incoherently-distributed (ID) and coherently-distributed (CD) sources is proposed based on multiple VMIMO systems. ID and CD sources are separated through the second-order blind identification (SOBI) algorithm. The traditional estimating signal parameters via the rotational invariance technique (ESPRIT)-based algorithm is valid only for one-dimensional (1D) DOA estimation for the ID source. By constructing the signal subspace, two rotational invariant relationships are constructed. Then, we extend the ESPRIT to estimate 2D DOAs for ID sources. For DOA estimation of CD sources, two rational invariance relationships are constructed based on the application of generalized steering vectors (GSVs). Then, the ESPRIT-based algorithm is used for estimating the eigenvalues of two rational invariance matrices, which contain the angular parameters. The expressions of azimuth and elevation for ID and CD sources have closed forms, which means that the spectrum peak searching is avoided. Therefore, compared to the traditional 2D DOA estimation algorithms, the proposed algorithm imposes significantly low computational complexity. The intersecting point of two rays, which come from two different directions measured by two uniform rectangle arrays (URA), can be regarded as the location of the biosensor (wearable sensor). Three BSs adopting the smart antenna (SA) technique cooperate with each other to locate the wearable sensors using the angulation positioning method. Simulation results demonstrate the effectiveness of the proposed algorithm. PMID:26985896
Wearable Sensor Localization Considering Mixed Distributed Sources in Health Monitoring Systems.
Wan, Liangtian; Han, Guangjie; Wang, Hao; Shu, Lei; Feng, Nanxing; Peng, Bao
2016-03-12
In health monitoring systems, the base station (BS) and the wearable sensors communicate with each other to construct a virtual multiple input and multiple output (VMIMO) system. In real applications, the signal that the BS received is a distributed source because of the scattering, reflection, diffraction and refraction in the propagation path. In this paper, a 2D direction-of-arrival (DOA) estimation algorithm for incoherently-distributed (ID) and coherently-distributed (CD) sources is proposed based on multiple VMIMO systems. ID and CD sources are separated through the second-order blind identification (SOBI) algorithm. The traditional estimating signal parameters via the rotational invariance technique (ESPRIT)-based algorithm is valid only for one-dimensional (1D) DOA estimation for the ID source. By constructing the signal subspace, two rotational invariant relationships are constructed. Then, we extend the ESPRIT to estimate 2D DOAs for ID sources. For DOA estimation of CD sources, two rational invariance relationships are constructed based on the application of generalized steering vectors (GSVs). Then, the ESPRIT-based algorithm is used for estimating the eigenvalues of two rational invariance matrices, which contain the angular parameters. The expressions of azimuth and elevation for ID and CD sources have closed forms, which means that the spectrum peak searching is avoided. Therefore, compared to the traditional 2D DOA estimation algorithms, the proposed algorithm imposes significantly low computational complexity. The intersecting point of two rays, which come from two different directions measured by two uniform rectangle arrays (URA), can be regarded as the location of the biosensor (wearable sensor). Three BSs adopting the smart antenna (SA) technique cooperate with each other to locate the wearable sensors using the angulation positioning method. Simulation results demonstrate the effectiveness of the proposed algorithm.
Fast instantaneous center of rotation estimation algorithm for a skied-steered robot
NASA Astrophysics Data System (ADS)
Kniaz, V. V.
2015-05-01
Skid-steered robots are widely used as mobile platforms for machine vision systems. However it is hard to achieve a stable motion of such robots along desired trajectory due to an unpredictable wheel slip. It is possible to compensate the unpredictable wheel slip and stabilize the motion of the robot using visual odometry. This paper presents a fast optical flow based algorithm for estimation of instantaneous center of rotation, angular and longitudinal speed of the robot. The proposed algorithm is based on Horn-Schunck variational optical flow estimation method. The instantaneous center of rotation and motion of the robot is estimated by back projection of optical flow field to the ground surface. The developed algorithm was tested using skid-steered mobile robot. The robot is based on a mobile platform that includes two pairs of differential driven motors and a motor controller. Monocular visual odometry system consisting of a singleboard computer and a low cost webcam is mounted on the mobile platform. A state-space model of the robot was derived using standard black-box system identification. The input (commands) and the output (motion) were recorded using a dedicated external motion capture system. The obtained model was used to control the robot without visual odometry data. The paper is concluded with the algorithm quality estimation by comparison of the trajectories estimated by the algorithm with the data from motion capture system.
NASA Astrophysics Data System (ADS)
Arabzadeh, Vida; Niaki, S. T. A.; Arabzadeh, Vahid
2017-10-01
One of the most important processes in the early stages of construction projects is to estimate the cost involved. This process involves a wide range of uncertainties, which make it a challenging task. Because of unknown issues, using the experience of the experts or looking for similar cases are the conventional methods to deal with cost estimation. The current study presents data-driven methods for cost estimation based on the application of artificial neural network (ANN) and regression models. The learning algorithms of the ANN are the Levenberg-Marquardt and the Bayesian regulated. Moreover, regression models are hybridized with a genetic algorithm to obtain better estimates of the coefficients. The methods are applied in a real case, where the input parameters of the models are assigned based on the key issues involved in a spherical tank construction. The results reveal that while a high correlation between the estimated cost and the real cost exists; both ANNs could perform better than the hybridized regression models. In addition, the ANN with the Levenberg-Marquardt learning algorithm (LMNN) obtains a better estimation than the ANN with the Bayesian-regulated learning algorithm (BRNN). The correlation between real data and estimated values is over 90%, while the mean square error is achieved around 0.4. The proposed LMNN model can be effective to reduce uncertainty and complexity in the early stages of the construction project.
A seismic coherency method using spectral amplitudes
NASA Astrophysics Data System (ADS)
Sui, Jing-Kun; Zheng, Xiao-Dong; Li, Yan-Dong
2015-09-01
Seismic coherence is used to detect discontinuities in underground media. However, strata with steeply dipping structures often produce false low coherence estimates and thus incorrect discontinuity characterization results. It is important to eliminate or reduce the effect of dipping on coherence estimates. To solve this problem, time-domain dip scanning is typically used to improve estimation of coherence in areas with steeply dipping structures. However, the accuracy of the time-domain estimation of dip is limited by the sampling interval. In contrast, the spectrum amplitude is not affected by the time delays in adjacent seismic traces caused by dipping structures. We propose a coherency algorithm that uses the spectral amplitudes of seismic traces within a predefined analysis window to construct the covariance matrix. The coherency estimates with the proposed algorithm is defined as the ratio between the dominant eigenvalue and the sum of all eigenvalues of the constructed covariance matrix. Thus, we eliminate the effect of dipping structures on coherency estimates. In addition, because different frequency bands of spectral amplitudes are used to estimate coherency, the proposed algorithm has multiscale features. Low frequencies are effective for characterizing large-scale faults, whereas high frequencies are better in characterizing small-scale faults. Application to synthetic and real seismic data show that the proposed algorithm can eliminate the effect of dip and produce better coherence estimates than conventional coherency algorithms in areas with steeply dipping structures.
Revised motion estimation algorithm for PROPELLER MRI.
Pipe, James G; Gibbs, Wende N; Li, Zhiqiang; Karis, John P; Schar, Michael; Zwart, Nicholas R
2014-08-01
To introduce a new algorithm for estimating data shifts (used for both rotation and translation estimates) for motion-corrected PROPELLER MRI. The method estimates shifts for all blades jointly, emphasizing blade-pair correlations that are both strong and more robust to noise. The heads of three volunteers were scanned using a PROPELLER acquisition while they exhibited various amounts of motion. All data were reconstructed twice, using motion estimates from the original and new algorithm. Two radiologists independently and blindly compared 216 image pairs from these scans, ranking the left image as substantially better or worse than, slightly better or worse than, or equivalent to the right image. In the aggregate of 432 scores, the new method was judged substantially better than the old method 11 times, and was never judged substantially worse. The new algorithm compared favorably with the old in its ability to estimate bulk motion in a limited study of volunteer motion. A larger study of patients is planned for future work. Copyright © 2013 Wiley Periodicals, Inc.
Distributed weighted least-squares estimation with fast convergence for large-scale systems.
Marelli, Damián Edgardo; Fu, Minyue
2015-01-01
In this paper we study a distributed weighted least-squares estimation problem for a large-scale system consisting of a network of interconnected sub-systems. Each sub-system is concerned with a subset of the unknown parameters and has a measurement linear in the unknown parameters with additive noise. The distributed estimation task is for each sub-system to compute the globally optimal estimate of its own parameters using its own measurement and information shared with the network through neighborhood communication. We first provide a fully distributed iterative algorithm to asymptotically compute the global optimal estimate. The convergence rate of the algorithm will be maximized using a scaling parameter and a preconditioning method. This algorithm works for a general network. For a network without loops, we also provide a different iterative algorithm to compute the global optimal estimate which converges in a finite number of steps. We include numerical experiments to illustrate the performances of the proposed methods.
Distributed weighted least-squares estimation with fast convergence for large-scale systems☆
Marelli, Damián Edgardo; Fu, Minyue
2015-01-01
In this paper we study a distributed weighted least-squares estimation problem for a large-scale system consisting of a network of interconnected sub-systems. Each sub-system is concerned with a subset of the unknown parameters and has a measurement linear in the unknown parameters with additive noise. The distributed estimation task is for each sub-system to compute the globally optimal estimate of its own parameters using its own measurement and information shared with the network through neighborhood communication. We first provide a fully distributed iterative algorithm to asymptotically compute the global optimal estimate. The convergence rate of the algorithm will be maximized using a scaling parameter and a preconditioning method. This algorithm works for a general network. For a network without loops, we also provide a different iterative algorithm to compute the global optimal estimate which converges in a finite number of steps. We include numerical experiments to illustrate the performances of the proposed methods. PMID:25641976
Sparse array angle estimation using reduced-dimension ESPRIT-MUSIC in MIMO radar.
Zhang, Chaozhu; Pang, Yucai
2013-01-01
Sparse linear arrays provide better performance than the filled linear arrays in terms of angle estimation and resolution with reduced size and low cost. However, they are subject to manifold ambiguity. In this paper, both the transmit array and receive array are sparse linear arrays in the bistatic MIMO radar. Firstly, we present an ESPRIT-MUSIC method in which ESPRIT algorithm is used to obtain ambiguous angle estimates. The disambiguation algorithm uses MUSIC-based procedure to identify the true direction cosine estimate from a set of ambiguous candidate estimates. The paired transmit angle and receive angle can be estimated and the manifold ambiguity can be solved. However, the proposed algorithm has high computational complexity due to the requirement of two-dimension search. Further, the Reduced-Dimension ESPRIT-MUSIC (RD-ESPRIT-MUSIC) is proposed to reduce the complexity of the algorithm. And the RD-ESPRIT-MUSIC only demands one-dimension search. Simulation results demonstrate the effectiveness of the method.
USDA-ARS?s Scientific Manuscript database
Several bio-optical algorithms were developed to estimate the chlorophyll-a (Chl-a) and phycocyanin (PC) concentrations in inland waters. This study aimed at identifying the influence of the algorithm parameters and wavelength bands on output variables and searching optimal parameter values. The opt...
A Direction of Arrival Estimation Algorithm Based on Orthogonal Matching Pursuit
NASA Astrophysics Data System (ADS)
Tang, Junyao; Cao, Fei; Liu, Lipeng
2018-02-01
The results show that the modified DSM is able to predict local buckling capacity of hot-rolled RHS and SHS accurately. In order to solve the problem of the weak ability of anti-radiation missile against active decoy in modern electronic warfare, a direction of arrival estimation algorithm based on orthogonal matching pursuit is proposed in this paper. The algorithm adopts the compression sensing technology. This paper uses array antennas to receive signals, gets the sparse representation of signals, and then designs the corresponding perception matrix. The signal is reconstructed by orthogonal matching pursuit algorithm to estimate the optimal solution. At the same time, the error of the whole measurement system is analyzed and simulated, and the validity of this algorithm is verified. The algorithm greatly reduces the measurement time, the quantity of equipment and the total amount of the calculation, and accurately estimates the angle and strength of the incoming signal. This technology can effectively improve the angle resolution of the missile, which is of reference significance to the research of anti-active decoy.