296 research outputs found
Reflected Shock Tunnel Noise Measurement by Focused Differential Interferometry
A series of experiments is conducted where a quantitative non-intrusive optical technique is used to investigate disturbances in the free-stream of T5, the free-piston driven reflected shock tunnel at Caltech. The optical technique, focused laser differential interferometry (FLDI), measures fluctuations in density. In the test matrix, reservoir enthalpy is varied while the reservoir pressure is held fixed. The results show the perturbations in density are not a strong function of the reservoir enthalpy. During one experiment, exceptional levels of noise were detected; this unique result is attributed to non-ideal operation of the shock tunnel. The data indicate that rms density fluctuations of less than 0.75% are achievable with attention to tunnel cleanliness. In addition, the spectral content of density fluctuation does not change throughout the test time
A precursor to the relational evaluation procedure: Analyzing stimulus equivalence II
A series of experiments examined the precursor to the
relational evaluation procedure (pREP). The pREP is capable of
facilitating derived relational responding, but it is less effective than
matching-to-sample (MTS) in producing equivalence class
formation. Part 1 of the present study tested possible reasons for
the inferiority of the. pREP relative to MTS. The first two
experiments compared the performances of subjects on two
modified versions of the pREP with their performances on a
simultaneous MTS procedure. The modifications did not improve
performances on the pREP. Experiment 3 compared the pREP
with a delayed MTS procedure but again MTS was more effective
than the pREP in producing equivalence. Part 2 of the study
determined whether pREP equivalence responding could be
facilitated by preexposing subjects to a history of MTS training and
testing. In Experiment 4, subjects were trained and tested on a
MTS procedure until they reliably produced both symmetry and
equivalence, and were then exposed to pREP training and testing
using the same stimuli, and relations among stimuli, as employed
for the MTS procedure. Following this, subjects were exposed to
pREP training and testing using novel stimuli. All subjects reliably
produced both symmetry and equivalence responding on the
pREP with both familiar arid novel stimuli. Experiment 5
determined whether using the same stimulus sets across the two
procedures was necessary. Results showed that if symmetry and
equivalence were shown on a MTS procedure followed
immediately by pREP training and testing using novel stimuli, only
2 out of 4 subjects successfully demonstrated both symmetry and
equivalence using the latter procedure
Проблемы специализированной помощи обожженным в России и пути их решения
На основании изучения динамики ожогового травматизма в России, тяжести травм и летальности среди больных с ожогами отмечено увеличение тяжести термической травмы, частоты раннего ожогового сепсиса и летальности среди взрослого населения, определены организационные и научные пути решения проблемы, повышения эффективности работы ожоговых центров.Basing on the study of the dynamics of burns in Russia, severity of the injury and death rate in the patients with burns the authors emphasize the increase in severity of thermal injury, incidence of early burn sepsis and death rate in adults. Organizational and scientific ways to solve the problem as well as to increase the efficacy of work of burn centers are defined
Deep Learning-Based Regression and Classification for Automatic Landmark Localization in Medical Images
In this study, we propose a fast and accurate method to automatically
localize anatomical landmarks in medical images. We employ a global-to-local
localization approach using fully convolutional neural networks (FCNNs). First,
a global FCNN localizes multiple landmarks through the analysis of image
patches, performing regression and classification simultaneously. In
regression, displacement vectors pointing from the center of image patches
towards landmark locations are determined. In classification, presence of
landmarks of interest in the patch is established. Global landmark locations
are obtained by averaging the predicted displacement vectors, where the
contribution of each displacement vector is weighted by the posterior
classification probability of the patch that it is pointing from. Subsequently,
for each landmark localized with global localization, local analysis is
performed. Specialized FCNNs refine the global landmark locations by analyzing
local sub-images in a similar manner, i.e. by performing regression and
classification simultaneously and combining the results. Evaluation was
performed through localization of 8 anatomical landmarks in CCTA scans, 2
landmarks in olfactory MR scans, and 19 landmarks in cephalometric X-rays. We
demonstrate that the method performs similarly to a second observer and is able
to localize landmarks in a diverse set of medical images, differing in image
modality, image dimensionality, and anatomical coverage.Comment: 12 pages, accepted at IEEE transactions in Medical Imagin
The effect of hunger state on hypothalamic functional connectivity in response to food cues
ACKNOWLEDGMENT The authors thank Lisette Charbonnier for her relentless efforts in setting up the study at all three sites and collecting the Dutch data. Open Access funding enabled and organized by Projekt DEAL. FUNDING INFORMATION This work was financially supported by the European Union Seventh Framework Programme (FP7/2007–2013) for research, technological development, and demonstration under grant agreement 266408 (Full4Health, www.full4health.eu). Furthermore, the study was supported in parts by a grant (01GI0925) from the Federal Ministry of Education and Research (BMBF) to the German Center for Diabetes Research (DZD e.V.).Peer reviewedPublisher PD
Assessing stimulus equivalence with a precursor to the relational evaluation procedure
Previous research has demonstrated that, after being trained on multiple match-to-sample (MTS) tasks (A-B, B-C), most human adults respond in accordance with symmetry (B-A, C-B) and equivalence (C-A) when measured with MTS tests and with a precursor to the Relational Evaluation Procedure (pREP). The latter procedure involves conditional go/no-go discrimination tasks, requiring subjects to press a bar during a 5s interval after the successive presentation of two same-class stimuli, and not to press after the presentation of two different-class stimuli (e.g. Ci -->Ai -->press, Ci -->Aj -->no press). The present study was an effort to replicate these findings. The study consisted of five experiments. Very few subjects evidenced pREP symmetry and equivalence unless they had (a) already demonstrated symmetry and equivalence in a MTS test before, or (b) received pREP pretraining with unrelated stimulus pairs and symmetry was tested before equivalence. Failures to show symmetry were always associated with pressing at or close to 50% of these trials. Failures to show equivalence were associated with pressing or not pressing on (almost) all trials. Current findings are similar to those obtained in equivalence studies involving MTS probes permitting the subjects not to respond to the designated comparisons
Reflected Shock Tunnel Noise Measurement by Focused Differential Interferometry
A series of experiments is conducted where a quantitative non-intrusive optical technique is used to investigate disturbances in the free-stream of T5, the free-piston driven reflected shock tunnel at Caltech. The optical technique, focused laser differential interferometry (FLDI), measures fluctuations in density. In the test matrix, reservoir enthalpy is varied while the reservoir pressure is held fixed. The results show the perturbations in density are not a strong function of the reservoir enthalpy. During one experiment, exceptional levels of noise were detected; this unique result is attributed to non-ideal operation of the shock tunnel. The data indicate that rms density fluctuations of less than 0.75% are achievable with attention to tunnel cleanliness. In addition, the spectral content of density fluctuation does not change throughout the test time
Good practice in food-related neuroimaging
The use of neuroimaging tools, especially functional magnetic resonance imaging, in nutritional research has increased substantially over the past 2 decades. Neuroimaging is a research tool with great potential impact on the field of nutrition, but to achieve that potential, appropriate use of techniques and interpretation of neuroimaging results is necessary. In this article, we present guidelines for good methodological practice in functional magnetic resonance imaging studies and flag specific limitations in the hope of helping researchers to make the most of neuroimaging tools and avoid potential pitfalls. We highlight specific considerations for food-related studies, such as how to adjust statistically for common confounders, like, for example, hunger state, menstrual phase, and BMI, as well as how to optimally match different types of food stimuli. Finally, we summarize current research needs and future directions, such as the use of prospective designs and more realistic paradigms for studying eating behavior
Relational frame theory and stimulus equivalence: Conceptual and procedural issues
The article begins with a brief outline of the phenomenon of stimulus equivalence and its relationship to human verbal behavior. Relational Frame Theory is then outlined as a behavior-analytic account of both stimulus equivalence and human language. The experimental procedures that have typically been used to examine stimulus equivalence are then considered, before focusing on a series of studies that have developed two alternative procedures for analyzing equivalence class formation: the respondent-type training procedure and the precursor to the relational evaluation procedure. Relational Frame Theory is used to interpret the results that have arisen from these two methodologies. The article concludes that the empirical and theoretical analyses of stimulus equivalence and derived relations, more generally, will be enhanced considerably through the development of a wide range of experimental preparations
Surgical Treatment of Diabetic Foot Ulcers Complicated by Osteomyelitis with Gentamicin-Loaded Calcium Sulphate-Hydroxyapatite Biocomposite
Diabetic foot ulcers, complicated by osteomyelitis, can be treated by surgical resection, dead space filling with gentamicin-loaded calcium sulphate-hydroxyapatite (CaS-HA) biocomposite, and closure of soft tissues and skin. To assess the feasibility of this treatment regimen, we conducted a multicenter retrospective cohort study of patients after failed conventional treatments. From 13 hospitals we included 64 patients with forefoot (n = 41 (64%)), midfoot (n = 14 (22%)), or hindfoot (n = 9 (14%)) ulcers complicated by osteomyelitis. Median follow-up was 43 (interquartile range, 20-61) weeks. We observed wound healing in 54 patients (84%) and treatment success (wound healing without ulcer recurrence) in 42 patients (66%). Treatment failures (no wound healing or ulcer recurrence) led to minor amputations in four patients (6%) and major amputations in seven patients (11%). Factors associated with treatment failures in univariable Cox regression analysis were gentamicin-resistant osteomyelitis (hazard ratio (HR), 3.847; 95%-confidence interval (CI), 1.065-13.899), hindfoot ulcers (HR, 3.624; 95%-CI, 1.187-11.060) and surgical procedures with gentamicin-loaded CaS-HA biocomposite that involved minor amputations (HR, 3.965; 95%-CI, 1.608-9.777). In this study of patients with diabetic foot ulcers, complicated by osteomyelitis, surgical treatment with gentamicin-loaded CaS-HA biocomposite was feasible and successful in 66% of patients. A prospective trial of this treatment regimen, based on a uniform treatment protocol, is required
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