Comparative study on the welded structure fatigue strength assessment method

NASA Astrophysics Data System (ADS)

Hu, Tao

2018-04-01

Due to the welding structure is widely applied in various industries, especially the pressure container, motorcycle, automobile, aviation, ship industry, such as large crane steel structure, so for welded structure fatigue strength evaluation is particularly important. For welded structure fatigue strength evaluation method mainly has four kinds of, the more from the use of two kinds of welded structure fatigue strength evaluation method, namely the nominal stress method and the hot spot stress evaluation method, comparing from its principle, calculation method for the process analysis and research, compare the similarities and the advantages and disadvantages, the analysis of practical engineering problems to provide the reference for every profession and trade, as well as the future welded structure fatigue strength and life evaluation method put forward outlook.

CARd-3D: Carbon Distribution in 3D Structure Program for Globular Proteins

PubMed Central

Ekambaram, Rajasekaran; Kannaiyan, Akila; Marimuthu, Vijayasarathy; Swaminathan, Vinobha Chinnaiah; Renganathan, Senthil; Perumal, Ananda Gopu

2014-01-01

Spatial arrangement of carbon in protein structure is analyzed here. Particularly, the carbon fractions around individual atoms are compared. It is hoped that it follows the principle of 31.45% carbon around individual atoms. The results reveal that globular protein's atoms follow this principle. A comparative study on monomer versus dimer reveal that carbon is better distributed in dimeric form than in its monomeric form. Similar study on solid versus liquid structures reveals that the liquid (NMR) structure has better carbon distribution over the corresponding solid (X-Ray) structure. The carbon fraction distributions in fiber and toxin protein are compared. Fiber proteins follow the principle of carbon fraction distribution. At the same time it has another broad spectrum of carbon distribution than in globular proteins. The toxin protein follows an abnormal carbon fraction distribution. The carbon fraction distribution plays an important role in deciding the structure and shape of proteins. It is hoped to help in understanding the protein folding and function. PMID:24748753

Comparative Protein Structure Modeling Using MODELLER.

PubMed

Webb, Benjamin; Sali, Andrej

2014-09-08

Functional characterization of a protein sequence is one of the most frequent problems in biology. This task is usually facilitated by accurate three-dimensional (3-D) structure of the studied protein. In the absence of an experimentally determined structure, comparative or homology modeling can sometimes provide a useful 3-D model for a protein that is related to at least one known protein structure. Comparative modeling predicts the 3-D structure of a given protein sequence (target) based primarily on its alignment to one or more proteins of known structure (templates). The prediction process consists of fold assignment, target-template alignment, model building, and model evaluation. This unit describes how to calculate comparative models using the program MODELLER and discusses all four steps of comparative modeling, frequently observed errors, and some applications. Modeling lactate dehydrogenase from Trichomonas vaginalis (TvLDH) is described as an example. The download and installation of the MODELLER software is also described. Copyright © 2014 John Wiley & Sons, Inc.

Comparative effectiveness of exercise, acupuncture, and spinal manipulation for low back pain.

PubMed

Standaert, Christopher J; Friedly, Janna; Erwin, Mark W; Lee, Michael J; Rechtine, Glenn; Henrikson, Nora B; Norvell, Daniel C

2011-10-01

Systematic review. We sought to answer the following clinical questions: (1) Is structured exercise more effective in the treatment of chronic low back pain (LBP) than spinal manipulative therapy (SMT)? (2) Is structured exercise more effective in the treatment of chronic LBP than acupuncture? (3) Is SMT more effective in the treatment of chronic LBP than acupuncture? (4) Do certain subgroups respond more favorably to specific treatments? (5) Are any of these treatments more cost-effective than the others? Exercise, SMT, and acupuncture are widely used interventions in the treatment of chronic LBP. There is evidence that all of these approaches may offer some benefit for patients with chronic LBP when compared with usual care or no treatment. The relative benefits or cost-effectiveness of any one of these treatments when compared with the others are less well-defined, and it is difficult to identify specific subgroups of those with chronic LBP who may preferentially respond to a particular treatment modality. A systematic review of the literature was performed to identify randomized controlled trials comparing a structured exercise program, SMT, or acupuncture with one another in patients with chronic LBP. Two studies were identified comparing the use of structured exercise with SMT that met our inclusion criteria. Although these studies utilized different approaches for the exercise and SMT treatment groups, patients in both groups improved in terms of pain and function in both studies. Using random-effects modeling, there was no difference between the exercise and SMT groups when the data from these studies were pooled. We identified no studies meeting our inclusion criteria that compared acupuncture with either structured exercise or SMT or that addressed the relative cost-effectiveness of these approaches in the treatment of patients with chronic LBP. The studies identified indicate that structured exercise and SMT appear to offer equivalent benefits in terms of pain and functional improvement for those with chronic LBP with clinical benefits evident within 8 weeks of care. However, the level of evidence is low. There is insufficient evidence to comment on the relative benefit of acupuncture compared with either structured exercise or SMT or to address the differential effects of structured exercise, SMT, or acupuncture for specific subgroups of individuals with chronic LBP. There is also insufficient evidence regarding the relative cost-effectiveness of structured exercise, SMT, or acupuncture in the treatment of chronic LBP. Structured exercise and SMT appear to offer equivalent benefits in the management of pain and function for patients with nonspecific chronic LBP. If no clinical benefit is appreciated after using one of these approaches for 8 weeks, then the treatment plan should be reevaluated and consideration should be given to modifying the treatment approach or using alternate forms of care. Strength of recommendation: Weak.There is insufficient evidence regarding the relative benefits of the acupuncture compared with either structured exercise or SMT in the treatment of chronic LBP.There is insufficient evidence to address differential effects of structured exercise, SMT, or acupuncture for specific subgroups of individuals with chronic LBP. There is insufficient evidence regarding the relative cost-effectiveness of structured exercise, SMT, or acupuncture in the treatment of chronic LBP.

Comparative Study of Physics Curriculum in Iran with Several Other Countries

ERIC Educational Resources Information Center

Shekarbaghani, Ashrafoalsadat

2016-01-01

This article is a qualitative study, which was done in 2013-2014. In this study using a comparative study was conducted to compare physics curriculum elements of Iran with the countries studied. Countries studied: Singapore, Turkey, India, England and Australia have diverse educational system. In this study, the structure of the educational…

Rigidified pneumatic composites

NASA Astrophysics Data System (ADS)

van Dessel, Steven

2000-10-01

The overall objective of the research presented in this dissertation was to address global issues of adequate housing for all and the need for more sustainable human settlement. In order to address these, the emerging technology of rigidified pneumatic composites was investigated. Rigidified pneumatic composites (RPC) are defined as thin flexible membrane structures that are pneumatically deployed. After deployment, these structures harden due to chemical or physical change of the membrane. Because of this change, these structures do no longer require pneumatic pressure to maintain their shape. For the first time, a systematic listing of the various means available to develop polymeric materials useful in RPC technology is presented. With the aim to reduce the cost of RPC structures, a new material was proposed, developed, and evaluated. This material involved the formation of a semi-interpenetrating polymer network based on poly vinyl chloride and an acrylate based reactive plasticizer. The economical and environmental performances of RPC structures using this new material were assessed by means of a case study. In this study, the performance of RPC technology was compared with that of a typical wood light frame structure in the application of a small single-family house. The study indicated that the cost of ownership in present day value for the RPC structure was approximately 33% less than the cost of a comparable wood light frame structure. The study also indicated that significant environmental benefits exist with the use of RPC structures. It was found that the RPC structure used significantly less resources compared to the wood light frame structure. About 3.5 times less materials coming from non-renewable fossil resources, about 2.5 times less materials coming from trees, and about 19 times less materials coming from inorganic resources was used in the RPC structure relative to the wood light frame structure. The study concluded with pointing out various means available to further increase the economical and environmental performance of RPC technology. Directions were provided to guide future developments of RPC technology.

Implementation of density functional theory method on object-oriented programming (C++) to calculate energy band structure using the projector augmented wave (PAW)

NASA Astrophysics Data System (ADS)

Alfianto, E.; Rusydi, F.; Aisyah, N. D.; Fadilla, R. N.; Dipojono, H. K.; Martoprawiro, M. A.

2017-05-01

This study implemented DFT method into the C++ programming language with object-oriented programming rules (expressive software). The use of expressive software results in getting a simple programming structure, which is similar to mathematical formula. This will facilitate the scientific community to develop the software. We validate our software by calculating the energy band structure of Silica, Carbon, and Germanium with FCC structure using the Projector Augmented Wave (PAW) method then compare the results to Quantum Espresso calculation’s results. This study shows that the accuracy of the software is 85% compared to Quantum Espresso.

Comparative Study on Cushion Performance Between 3D Printed Kelvin Structure and 3D Printed Lattice Structure

NASA Astrophysics Data System (ADS)

Priyadarshini, Lakshmi

Frequently transported packaging goods are more prone to damage due to impact, jolting or vibration in transit. Fragile goods, for example, glass, ceramics, porcelain are susceptible to mechanical stresses. Hence ancillary materials like cushions play an important role when utilized within package. In this work, an analytical model of a 3D cellular structure is established based on Kelvin model and lattice structure. The research will provide a comparative study between the 3D printed Kelvin unit structure and 3D printed lattice structure. The comparative investigation is based on parameters defining cushion performance such as cushion creep, indentation, and cushion curve analysis. The applications of 3D printing is in rapid prototyping where the study will provide information of which model delivers better form of energy absorption. 3D printed foam will be shown as a cost-effective approach as prototype. The research also investigates about the selection of material for 3D printing process. As cushion development demands flexible material, three-dimensional printing with material having elastomeric properties is required. Further, the concept of cushion design is based on Kelvin model structure and lattice structure. The analytical solution provides the cushion curve analysis with respect to the results observed when load is applied over the cushion. The results are reported on basis of attenuation and amplification curves.

Cortical Thinning and Altered Cortico-Cortical Structural Covariance of the Default Mode Network in Patients with Persistent Insomnia Symptoms.

PubMed

Suh, Sooyeon; Kim, Hosung; Dang-Vu, Thien Thanh; Joo, Eunyeon; Shin, Chol

2016-01-01

Recent studies have suggested that structural abnormalities in insomnia may be linked with alterations in the default-mode network (DMN). This study compared cortical thickness and structural connectivity linked to the DMN in patients with persistent insomnia (PI) and good sleepers (GS). The current study used a clinical subsample from the longitudinal community-based Korean Genome and Epidemiology Study (KoGES). Cortical thickness and structural connectivity linked to the DMN in patients with persistent insomnia symptoms (PIS; n = 57) were compared to good sleepers (GS; n = 40). All participants underwent MRI acquisition. Based on literature review, we selected cortical regions corresponding to the DMN. A seed-based structural covariance analysis measured cortical thickness correlation between each seed region of the DMN and other cortical areas. Association of cortical thickness and covariance with sleep quality and neuropsychological assessments were further assessed. Compared to GS, cortical thinning was found in PIS in the anterior cingulate cortex, precentral cortex, and lateral prefrontal cortex. Decreased structural connectivity between anterior and posterior regions of the DMN was observed in the PIS group. Decreased structural covariance within the DMN was associated with higher PSQI scores. Cortical thinning in the lateral frontal lobe was related to poor performance in executive function in PIS. Disrupted structural covariance network in PIS might reflect malfunctioning of antero-posterior disconnection of the DMN during the wake to sleep transition that is commonly found during normal sleep. The observed structural network alteration may further implicate commonly observed sustained sleep difficulties and cognitive impairment in insomnia. © 2016 Associated Professional Sleep Societies, LLC.

Understanding differences between summer vs. school obesogenic behaviors of children: the structured days hypothesis.

PubMed

Brazendale, Keith; Beets, Michael W; Weaver, R Glenn; Pate, Russell R; Turner-McGrievy, Gabrielle M; Kaczynski, Andrew T; Chandler, Jessica L; Bohnert, Amy; von Hippel, Paul T

2017-07-26

Although the scientific community has acknowledged modest improvements can be made to weight status and obesogenic behaviors (i.e., physical activity, sedentary/screen time, diet, and sleep) during the school year, studies suggests improvements are erased as elementary-age children are released to summer vacation. Emerging evidence shows children return to school after summer vacation displaying accelerated weight gain compared to the weight gained occurring during the school year. Understanding how summer days differ from when children are in school is, therefore, essential. There is limited evidence on the etiology of accelerated weight gain during summer, with few studies comparing obesogenic behaviors on the same children during school and summer. For many children, summer days may be analogous to weekend days throughout the school year. Weekend days are often limited in consistent and formal structure, and thus differ from school days where segmented, pre-planned, restrictive, and compulsory components exist that shape obesogenic behaviors. The authors hypothesize that obesogenic behaviors are beneficially regulated when children are exposed to a structured day (i.e., school weekday) compared to what commonly occurs during summer. This is referred to as the 'Structured Days Hypothesis' (SDH). To illustrate how the SDH operates, this study examines empirical data that compares weekend day (less-structured) versus weekday (structured) obesogenic behaviors in U.S. elementary school-aged children. From 190 studies, 155 (~80%) demonstrate elementary-aged children's obesogenic behaviors are more unfavorable during weekend days compared to weekdays. In light of the SDH, consistent evidence demonstrates the structured environment of weekdays may help to protect children by regulating obesogenic behaviors, most likely through compulsory physical activity opportunities, restricting caloric intake, reducing screen time occasions, and regulating sleep schedules. Summer is emerging as the critical period where childhood obesity prevention efforts need to be focused. The SDH can help researchers understand the drivers of obesogenic behaviors during summer and lead to innovative intervention development.

Impact of Diagnosticity on the Adequacy of Models for Cognitive Diagnosis under a Linear Attribute Structure: A Simulation Study

ERIC Educational Resources Information Center

de La Torre, Jimmy; Karelitz, Tzur M.

2009-01-01

Compared to unidimensional item response models (IRMs), cognitive diagnostic models (CDMs) based on latent classes represent examinees' knowledge and item requirements using discrete structures. This study systematically examines the viability of retrofitting CDMs to IRM-based data with a linear attribute structure. The study utilizes a procedure…

Comparing Assessment Methods in Undergraduate Statistics Courses

ERIC Educational Resources Information Center

Baxter, Sarah E.

2017-01-01

The purpose of this study was to compare undergraduate students' academic performance and attitudes about statistics in the context of two different types of assessment structures for an introductory statistics course. One assessment structure used in-class quizzes that emphasized computation and procedural fluency as well as vocabulary…

Volume changes in unrestrained structural lightweight concrete.

DOT National Transportation Integrated Search

1964-08-01

In this study a comparator-type measuring system was developed to accurately determine volume change characteristics of one structural lightweight concrete. The specific properties studied were the coefficient of linear thermal expansion and unrestra...

Quantitative structure-activity relationship of organosulphur compounds as soybean 15-lipoxygenase inhibitors using CoMFA and CoMSIA.

PubMed

Caballero, Julio; Fernández, Michael; Coll, Deysma

2010-12-01

Three-dimensional quantitative structure-activity relationship studies were carried out on a series of 28 organosulphur compounds as 15-lipoxygenase inhibitors using comparative molecular field analysis and comparative molecular similarity indices analysis. Quantitative information on structure-activity relationships is provided for further rational development and direction of selective synthesis. All models were carried out over a training set including 22 compounds. The best comparative molecular field analysis model only included steric field and had a good Q² = 0.789. Comparative molecular similarity indices analysis overcame the comparative molecular field analysis results: the best comparative molecular similarity indices analysis model also only included steric field and had a Q² = 0.894. In addition, this model predicted adequately the compounds contained in the test set. Furthermore, plots of steric comparative molecular similarity indices analysis field allowed conclusions to be drawn for the choice of suitable inhibitors. In this sense, our model should prove useful in future 15-lipoxygenase inhibitor design studies. © 2010 John Wiley & Sons A/S.

A study on different morphological structures of zinc oxide nanostructures for humidity sensing application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ismail, A. S., E-mail: kyrin-samaxi@yahoo.com; Mamat, M. H., E-mail: mhmamat@salam.uitm.edu.my; Rusop, M., E-mail: rusop@salam.uitm.my

2016-07-06

Effects of different morphological structures of ZnO to the performance of the device in the humidity sensing have been studied. Two different kinds of nanostructures were obtained which are nanords and nanoflakes. From the surface morphology image, the ZnO nanoflakes has lower diameter size of 100 nm compared to ZnO nanorods of 250 nm. The ZnO nanoflakes are not aligned and has low porous structure compared to ZnO nanorods. The humidity sensor performance of ZnO nanorods has superior performance compared to ZnO nanoflakes. The sensitivity of the ZnO nanorods sensor is 3.20 which are almost two times higher than themore » ZnO nanoflakes of 1.65. The structural properties of the samples have been characterized using field emission scanning electron microscopy (FESEM) electrical properties has been characterized using current voltage (I-V) measurement.« less

Structural stability of myoglobin and glycomyoglobin: a comparative molecular dynamics simulation study.

PubMed

Alizadeh-Rahrovi, Joulia; Shayesteh, Alireza; Ebrahim-Habibi, Azadeh

2015-09-01

Glycoproteins are formed as the result of enzymatic glycosylation or chemical glycation in the body, and produced in vitro in industrial processes. The covalently attached carbohydrate molecule(s) confer new properties to the protein, including modified stability. In the present study, the structural stability of a glycoprotein form of myoglobin, bearing a glucose unit in the N-terminus, has been compared with its native form by the use of molecular dynamics simulation. Both structures were subjected to temperatures of 300 and 500 K in an aqueous environment for 10 ns. Changes in secondary structures and RMSD were then assessed. An overall higher stability was detected for glycomyoglobin, for which the most stable segments/residues were highlighted and compared with the native form. The simple addition of a covalently bound glucose is suggested to exert its stabilizing effect via increased contacts with surrounding water molecules, as well as a different pattern of interactions with neighbor residues.

3D-quantitative structure-activity relationship studies on benzothiadiazepine hydroxamates as inhibitors of tumor necrosis factor-alpha converting enzyme.

PubMed

Murumkar, Prashant R; Giridhar, Rajani; Yadav, Mange Ram

2008-04-01

A set of 29 benzothiadiazepine hydroxamates having selective tumor necrosis factor-alpha converting enzyme inhibitory activity were used to compare the quality and predictive power of 3D-quantitative structure-activity relationship, comparative molecular field analysis, and comparative molecular similarity indices models for the atom-based, centroid/atom-based, data-based, and docked conformer-based alignment. Removal of two outliers from the initial training set of molecules improved the predictivity of models. Among the 3D-quantitative structure-activity relationship models developed using the above four alignments, the database alignment provided the optimal predictive comparative molecular field analysis model for the training set with cross-validated r(2) (q(2)) = 0.510, non-cross-validated r(2) = 0.972, standard error of estimates (s) = 0.098, and F = 215.44 and the optimal comparative molecular similarity indices model with cross-validated r(2) (q(2)) = 0.556, non-cross-validated r(2) = 0.946, standard error of estimates (s) = 0.163, and F = 99.785. These models also showed the best test set prediction for six compounds with predictive r(2) values of 0.460 and 0.535, respectively. The contour maps obtained from 3D-quantitative structure-activity relationship studies were appraised for activity trends for the molecules analyzed. The comparative molecular similarity indices models exhibited good external predictivity as compared with that of comparative molecular field analysis models. The data generated from the present study helped us to further design and report some novel and potent tumor necrosis factor-alpha converting enzyme inhibitors.

Comparative study of the pentamodal property of four potential pentamode microstructures

NASA Astrophysics Data System (ADS)

Huang, Yan; Lu, Xuegang; Liang, Gongying; Xu, Zhuo

2017-03-01

In this paper, a numerical comparative study is presented on the pentamodal property of four potential pentamode microstructures (three based on simple cubic and one on body-centered cubic structures) based on phonon band calculations. The finite-element method is employed to calculate the band structures, and the two essential factors of the ratio of bulk modulus B to shear modulus G and the single-mode band gap (SBG) are analyzed to quantitatively evaluate the pentamodal property. The results show that all four structures possess a higher B/G ratio than traditional materials. One of the simple cubic structures exhibits the incomplete SBG, while the three other structures exhibit complete SBG to decouple the compression and shear waves in all propagation directions. Further parametric analyses are presented investigating the effects of geometrical and material parameters on the pentamodal property of these structures. This study provides guidelines for the future design of novel pentamode microstructures possessing a high B/G ratio and a low-frequency broadband SBG.

Reliability-based structural optimization: A proposed analytical-experimental study

NASA Technical Reports Server (NTRS)

Stroud, W. Jefferson; Nikolaidis, Efstratios

1993-01-01

An analytical and experimental study for assessing the potential of reliability-based structural optimization is proposed and described. In the study, competing designs obtained by deterministic and reliability-based optimization are compared. The experimental portion of the study is practical because the structure selected is a modular, actively and passively controlled truss that consists of many identical members, and because the competing designs are compared in terms of their dynamic performance and are not destroyed if failure occurs. The analytical portion of this study is illustrated on a 10-bar truss example. In the illustrative example, it is shown that reliability-based optimization can yield a design that is superior to an alternative design obtained by deterministic optimization. These analytical results provide motivation for the proposed study, which is underway.

Confirming the Factor Structure of the Cognitive Test Anxiety Scale: Comparing the Utility of Three Solutions

ERIC Educational Resources Information Center

Cassady, Jerrell C.; Finch, W. Holmes

2014-01-01

This study validated the factor structure of a popular assessment of learner's cognitive test anxiety. Following recent findings in a study with Argentinean students' use of the Spanish version of the Cognitive Test Anxiety Scale (CTAS), this study tested the factor structure using data from 742 students who completed the original English version…

Permeability study of cancellous bone and its idealised structures.

PubMed

Syahrom, Ardiyansyah; Abdul Kadir, Mohammed Rafiq; Harun, Muhamad Nor; Öchsner, Andreas

2015-01-01

Artificial bone is a suitable alternative to autografts and allografts, however their use is still limited. Though there were numerous reports on their structural properties, permeability studies of artificial bones were comparably scarce. This study focused on the development of idealised, structured models of artificial cancellous bone and compared their permeability values with bone surface area and porosity. Cancellous bones from fresh bovine femur were extracted and cleaned following an established protocol. The samples were scanned using micro-computed tomography (μCT) and three-dimensional models of the cancellous bones were reconstructed for morphology study. Seven idealised and structured cancellous bone models were then developed and fabricated via rapid prototyping technique. A test-rig was developed and permeability tests were performed on the artificial and real cancellous bones. The results showed a linear correlation between the permeability and the porosity as well as the bone surface area. The plate-like idealised structure showed a similar value of permeability to the real cancellous bones. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Atomistic study on the FCC/BCC interface structure with {112}KS orientation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Keonwook; Beyerlein, Irene; Han, Weizhong

2011-09-23

In this study, atomistic simulation is used to explore the atomic interface structure, the intrinsic defect network, and mechanism of twin formation from the {112}KS Cu-Nb interface. The interface structure of different material systems AI-Fe and AI-Nb are also compared with Cu-Nb interface.

[Study on Abnormal Topological Properties of Structural Brain Networks of Patients with Depression Comorbid with Anxiety].

PubMed

Wu, Xiuyong; Wu, Xiaoming; Peng, Hongjun; Ning, Yuping; Wu, Kai

2016-06-01

This paper is aimed to analyze the topological properties of structural brain networks in depressive patients with and without anxiety and to explore the neuropath logical mechanisms of depression comorbid with anxiety.Diffusion tensor imaging and deterministic tractography were applied to map the white matter structural networks.We collected 20 depressive patients with anxiety(DPA),18 depressive patients without anxiety(DP),and 28 normal controls(NC)as comparative groups.The global and nodal properties of the structural brain networks in the three groups were analyzed with graph theoretical methods.The result showed that1 the structural brain networks in three groups showed small-world properties and highly connected global hubs predominately from association cortices;2DP group showed lower local efficiency and global efficiency compared to NC group,whereas DPA group showed higher local efficiency and global efficiency compared to NC group;3significant differences of network properties(clustering coefficient,characteristic path lengths,local efficiency,global efficiency)were found between DPA and DP groups;4DP group showed significant changes of nodal efficiency in the brain areas primarily in the temporal lobe and bilateral frontal gyrus,compared to DPA and NC groups.The analysis indicated that the DP and DPA groups showed nodal properties of the structural brain networks,compared to NC group.Moreover,the two diseased groups indicated an opposite trend in the network properties.The results of this study may provide a new imaging index for clinical diagnosis for depression comorbid with anxiety.

Differentiating between bipolar and unipolar depression in functional and structural MRI studies.

PubMed

Han, Kyu-Man; De Berardis, Domenico; Fornaro, Michele; Kim, Yong-Ku

2018-03-28

Distinguishing depression in bipolar disorder (BD) from unipolar depression (UD) solely based on clinical clues is difficult, which has led to the exploration of promising neural markers in neuroimaging measures for discriminating between BD depression and UD. In this article, we review structural and functional magnetic resonance imaging (MRI) studies that directly compare UD and BD depression based on neuroimaging modalities including functional MRI studies on regional brain activation or functional connectivity, structural MRI on gray or white matter morphology, and pattern classification analyses using a machine learning approach. Numerous studies have reported distinct functional and structural alterations in emotion- or reward-processing neural circuits between BD depression and UD. Different activation patterns in neural networks including the amygdala, anterior cingulate cortex (ACC), prefrontal cortex (PFC), and striatum during emotion-, reward-, or cognition-related tasks have been reported between BD and UD. A stronger functional connectivity pattern in BD was pronounced in default mode and in frontoparietal networks and brain regions including the PFC, ACC, parietal and temporal regions, and thalamus compared to UD. Gray matter volume differences in the ACC, hippocampus, amygdala, and dorsolateral prefrontal cortex (DLPFC) have been reported between BD and UD, along with a thinner DLPFC in BD compared to UD. BD showed reduced integrity in the anterior part of the corpus callosum and posterior cingulum compared to UD. Several studies performed pattern classification analysis using structural and functional MRI data to distinguish between UD and BD depression using a supervised machine learning approach, which yielded a moderate level of accuracy in classification. Copyright © 2018 Elsevier Inc. All rights reserved.

The Use of Carcasses for the Analysis of Cetacean Population Genetic Structure: A Comparative Study in Two Dolphin Species

PubMed Central

Bilgmann, Kerstin; Möller, Luciana M.; Harcourt, Robert G.; Kemper, Catherine M.; Beheregaray, Luciano B.

2011-01-01

Advances in molecular techniques have enabled the study of genetic diversity and population structure in many different contexts. Studies that assess the genetic structure of cetacean populations often use biopsy samples from free-ranging individuals and tissue samples from stranded animals or individuals that became entangled in fishery or aquaculture equipment. This leads to the question of how representative the location of a stranded or entangled animal is with respect to its natural range, and whether similar results would be obtained when comparing carcass samples with samples from free-ranging individuals in studies of population structure. Here we use tissue samples from carcasses of dolphins that stranded or died as a result of bycatch in South Australia to investigate spatial population structure in two species: coastal bottlenose (Tursiops sp.) and short-beaked common dolphins (Delphinus delphis). We compare these results with those previously obtained from biopsy sampled free-ranging dolphins in the same area to test whether carcass samples yield similar patterns of genetic variability and population structure. Data from dolphin carcasses were gathered using seven microsatellite markers and a fragment of the mitochondrial DNA control region. Analyses based on carcass samples alone failed to detect genetic structure in Tursiops sp., a species previously shown to exhibit restricted dispersal and moderate genetic differentiation across a small spatial scale in this region. However, genetic structure was correctly inferred in D. delphis, a species previously shown to have reduced genetic structure over a similar geographic area. We propose that in the absence of corroborating data, and when population structure is assessed over relatively small spatial scales, the sole use of carcasses may lead to an underestimate of genetic differentiation. This can lead to a failure in identifying management units for conservation. Therefore, this risk should be carefully assessed when planning population genetic studies of cetaceans. PMID:21655285

Cortical Thinning and Altered Cortico-Cortical Structural Covariance of the Default Mode Network in Patients with Persistent Insomnia Symptoms

PubMed Central

Suh, Sooyeon; Kim, Hosung; Dang-Vu, Thien Thanh; Joo, Eunyeon; Shin, Chol

2016-01-01

Study Objectives: Recent studies have suggested that structural abnormalities in insomnia may be linked with alterations in the default-mode network (DMN). This study compared cortical thickness and structural connectivity linked to the DMN in patients with persistent insomnia (PI) and good sleepers (GS). Methods: The current study used a clinical subsample from the longitudinal community-based Korean Genome and Epidemiology Study (KoGES). Cortical thickness and structural connectivity linked to the DMN in patients with persistent insomnia symptoms (PIS; n = 57) were compared to good sleepers (GS; n = 40). All participants underwent MRI acquisition. Based on literature review, we selected cortical regions corresponding to the DMN. A seed-based structural covariance analysis measured cortical thickness correlation between each seed region of the DMN and other cortical areas. Association of cortical thickness and covariance with sleep quality and neuropsychological assessments were further assessed. Results: Compared to GS, cortical thinning was found in PIS in the anterior cingulate cortex, precentral cortex, and lateral prefrontal cortex. Decreased structural connectivity between anterior and posterior regions of the DMN was observed in the PIS group. Decreased structural covariance within the DMN was associated with higher PSQI scores. Cortical thinning in the lateral frontal lobe was related to poor performance in executive function in PIS. Conclusion: Disrupted structural covariance network in PIS might reflect malfunctioning of antero-posterior disconnection of the DMN during the wake to sleep transition that is commonly found during normal sleep. The observed structural network alteration may further implicate commonly observed sustained sleep difficulties and cognitive impairment in insomnia. Citation: Suh S, Kim H, Dang-Vu TT, Joo E, Shin C. Cortical thinning and altered cortico-cortical structural covariance of the default mode network in patients with persistent insomnia symptoms. SLEEP 2016;39(1):161–171. PMID:26414892

Structures of School Systems Worldwide: A Comparative Study

ERIC Educational Resources Information Center

Popov, Nikolay

2012-01-01

In the past 20 years I have been examining the structures of school systems worldwide. This ongoing research has been enriched by the findings obtained from the lecture course on Comparative Education I have been delivering to students in the Bachelor and Master's Education Programs at Sofia University, Bulgaria. This paper presents some results…

Non-structural carbohydrates in woody plants compared among laboratories

Treesearch

Audrey G. Quentin; Elizabeth A. Pinkard; Michael G. Ryan; David T. Tissue; L. Scott Baggett; Henry D. Adams; Pascale Maillard; Jacqueline Marchand; Simon M. Landhausser; Andre Lacointe; Yves Gibon; William R. L. Anderegg; Shinichi Asao; Owen K. Atkin; Marc Bonhomme; Caroline Claye; Pak S. Chow; Anne Clement-Vidal; Noel W. Davies; L. Turin Dickman; Rita Dumbur; David S. Ellsworth; Kristen Falk; Lucía Galiano; Jose M. Grunzweig; Henrik Hartmann; Gunter Hoch; Sharon Hood; Joanna E. Jones; Takayoshi Koike; Iris Kuhlmann; Francisco Lloret; Melchor Maestro; Shawn D. Mansfield; Jordi Martinez-Vilalta; Mickael Maucourt; Nathan G. McDowell; Annick Moing; Bertrand Muller; Sergio G. Nebauer; Ulo Niinemets; Sara Palacio; Frida Piper; Eran Raveh; Andreas Richter; Gaelle Rolland; Teresa Rosas; Brigitte Saint Joanis; Anna Sala; Renee A. Smith; Frank Sterck; Joseph R. Stinziano; Mari Tobias; Faride Unda; Makoto Watanabe; Danielle A. Way; Lasantha K. Weerasinghe; Birgit Wild; Erin Wiley; David R. Woodruff

2016-01-01

Non-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also...

Opening the Door: A Comparative Study of Leadership Competencies of Traditional and Nontraditional Superintendents

ERIC Educational Resources Information Center

Usmani, Sarah

2010-01-01

The purpose of this study was to compare the leadership competencies of the two types of superintendents: traditional and nontraditional superintendents in urban school districts. The study examined the essential skills required of all superintendents and compared these skills between the two superintendent categories. Structured interviews were…

Protein comparability assessments and potential applicability of high throughput biophysical methods and data visualization tools to compare physical stability profiles

PubMed Central

Alsenaidy, Mohammad A.; Jain, Nishant K.; Kim, Jae H.; Middaugh, C. Russell; Volkin, David B.

2014-01-01

In this review, some of the challenges and opportunities encountered during protein comparability assessments are summarized with an emphasis on developing new analytical approaches to better monitor higher-order protein structures. Several case studies are presented using high throughput biophysical methods to collect protein physical stability data as function of temperature, agitation, ionic strength and/or solution pH. These large data sets were then used to construct empirical phase diagrams (EPDs), radar charts, and comparative signature diagrams (CSDs) for data visualization and structural comparisons between the different proteins. Protein samples with different sizes, post-translational modifications, and inherent stability are presented: acidic fibroblast growth factor (FGF-1) mutants, different glycoforms of an IgG1 mAb prepared by deglycosylation, as well as comparisons of different formulations of an IgG1 mAb and granulocyte colony stimulating factor (GCSF). Using this approach, differences in structural integrity and conformational stability profiles were detected under stress conditions that could not be resolved by using the same techniques under ambient conditions (i.e., no stress). Thus, an evaluation of conformational stability differences may serve as an effective surrogate to monitor differences in higher-order structure between protein samples. These case studies are discussed in the context of potential utility in protein comparability studies. PMID:24659968

Protein comparability assessments and potential applicability of high throughput biophysical methods and data visualization tools to compare physical stability profiles.

PubMed

Alsenaidy, Mohammad A; Jain, Nishant K; Kim, Jae H; Middaugh, C Russell; Volkin, David B

2014-01-01

In this review, some of the challenges and opportunities encountered during protein comparability assessments are summarized with an emphasis on developing new analytical approaches to better monitor higher-order protein structures. Several case studies are presented using high throughput biophysical methods to collect protein physical stability data as function of temperature, agitation, ionic strength and/or solution pH. These large data sets were then used to construct empirical phase diagrams (EPDs), radar charts, and comparative signature diagrams (CSDs) for data visualization and structural comparisons between the different proteins. Protein samples with different sizes, post-translational modifications, and inherent stability are presented: acidic fibroblast growth factor (FGF-1) mutants, different glycoforms of an IgG1 mAb prepared by deglycosylation, as well as comparisons of different formulations of an IgG1 mAb and granulocyte colony stimulating factor (GCSF). Using this approach, differences in structural integrity and conformational stability profiles were detected under stress conditions that could not be resolved by using the same techniques under ambient conditions (i.e., no stress). Thus, an evaluation of conformational stability differences may serve as an effective surrogate to monitor differences in higher-order structure between protein samples. These case studies are discussed in the context of potential utility in protein comparability studies.

Fantasy Play of Preschoolers as a Function of Toy Structures.

ERIC Educational Resources Information Center

Einsiedler, Wolfgang

Two studies are presented which investigate the influence of various toy structures on the frequency of individual fantasy play forms in 3- to 6-year-old children. In the first study, the effects of high-realistic/high-complexity and low-realistic/low-complexity toy structures were compared. There were significant main effects for the factor toy…

Good Things Come in Threes: Single-Parent Multigenerational Family Structure and Adolescent Adjustment. JCPR Working Paper.

ERIC Educational Resources Information Center

DeLeire, Thomas; Kalil, Ariel

This research used data from the 1998 National Educational Longitudinal Study to investigate the development of outcomes for adolescents living with single mothers in multigenerational families compared with adolescents living in married families (as well as a disaggregated set of other family structures). The study measured family structure when…

Interaction of native and apo-carbonic anhydrase with hydrophobic adsorbents: A comparative structure-function study.

PubMed

Salemi, Zahra; Hosseinkhani, Saman; Ranjbar, Bijan; Nemat-Gorgani, Mohsen

2006-09-30

Our previous studies indicated that native carbonic anhydrase does not interact with hydrophobic adsorbents and that it acquires this ability upon denaturation. In the present study, an apo form of the enzyme was prepared by removal of zinc and a comparative study was performed on some characteristic features of the apo and native forms by far- and near-UV circular dichroism (CD), intrinsic fluorescent spectroscopy, 1-anilino naphthalene-8-sulfonate (ANS) binding, fluorescence quenching by acrylamide, and Tm measurement. Results indicate that protein flexibility is enhanced and the hydrophobic sites become more exposed upon conversion to the apo form. Accordingly, the apo structure showed a greater affinity for interaction with hydrophobic adsorbents as compared with the native structure. As observed for the native enzyme, heat denaturation of the apo form promoted interaction with alkyl residues present on the adsorbents and, by cooling followed by addition of zinc, catalytically-active immobilized preparations were obtained.

Experimental and Computational Study of Sonic and Supersonic Jet Plumes

NASA Technical Reports Server (NTRS)

Venkatapathy, E.; Naughton, J. W.; Fletcher, D. G.; Edwards, Thomas A. (Technical Monitor)

1994-01-01

Study of sonic and supersonic jet plumes are relevant to understanding such phenomenon as jet-noise, plume signatures, and rocket base-heating and radiation. Jet plumes are simple to simulate and yet, have complex flow structures such as Mach disks, triple points, shear-layers, barrel shocks, shock-shear-layer interaction, etc. Experimental and computational simulation of sonic and supersonic jet plumes have been performed for under- and over-expanded, axisymmetric plume conditions. The computational simulation compare very well with the experimental observations of schlieren pictures. Experimental data such as temperature measurements with hot-wire probes are yet to be measured and will be compared with computed values. Extensive analysis of the computational simulations presents a clear picture of how the complex flow structure develops and the conditions under which self-similar flow structures evolve. From the computations, the plume structure can be further classified into many sub-groups. In the proposed paper, detail results from the experimental and computational simulations for single, axisymmetric, under- and over-expanded, sonic and supersonic plumes will be compared and the fluid dynamic aspects of flow structures will be discussed.

Electronic structure of p-type transparent conducting oxide CuAlO2

NASA Astrophysics Data System (ADS)

Mo, Sung-Kwan; Yoon, Joonseok; Liu, Xiaosong; Yang, Wanli; Mun, Bongjin; Ju, Honglyoul

2014-03-01

CuAlO2 is a prototypical p-type transparent conducting oxide. Despite its importance for potential applications and number of studies on its band structure and gap characteristics, experimental study on the momentum-resolved electronic structure has been lacking. We present angle-resolved photoemission data on single crystalline CuAlO2 using synchrotron light source to reveal complete band structure. Complemented by the x-ray absorption and emission spectra, we also study band gap characteristics and compare them with theory.

A structural SVM approach for reference parsing.

PubMed

Zhang, Xiaoli; Zou, Jie; Le, Daniel X; Thoma, George R

2011-06-09

Automated extraction of bibliographic data, such as article titles, author names, abstracts, and references is essential to the affordable creation of large citation databases. References, typically appearing at the end of journal articles, can also provide valuable information for extracting other bibliographic data. Therefore, parsing individual reference to extract author, title, journal, year, etc. is sometimes a necessary preprocessing step in building citation-indexing systems. The regular structure in references enables us to consider reference parsing a sequence learning problem and to study structural Support Vector Machine (structural SVM), a newly developed structured learning algorithm on parsing references. In this study, we implemented structural SVM and used two types of contextual features to compare structural SVM with conventional SVM. Both methods achieve above 98% token classification accuracy and above 95% overall chunk-level accuracy for reference parsing. We also compared SVM and structural SVM to Conditional Random Field (CRF). The experimental results show that structural SVM and CRF achieve similar accuracies at token- and chunk-levels. When only basic observation features are used for each token, structural SVM achieves higher performance compared to SVM since it utilizes the contextual label features. However, when the contextual observation features from neighboring tokens are combined, SVM performance improves greatly, and is close to that of structural SVM after adding the second order contextual observation features. The comparison of these two methods with CRF using the same set of binary features show that both structural SVM and CRF perform better than SVM, indicating their stronger sequence learning ability in reference parsing.

Autonomous versus Merged Marketing Departments: The Impact of Current Department Structure and Previous Restructuring Experience on Faculty Perceptions

ERIC Educational Resources Information Center

Neese, William T.; Batory, Stephen S.

2005-01-01

This study details faculty perceptions concerning administrative structure and its impact on issues such as collegiality or student success. Faculty members in autonomous marketing departments are compared with those in combined units. Then, faculty never involved with departmental change are compared with faculty previously involved splitting…

A Comparative Analysis of the Costs of Administration of an OSCE.

ERIC Educational Resources Information Center

Cusimano, Michael D.; And Others

1994-01-01

A study compared the costs of a six-station structured oral examination and an objective structured clinical examination (OSCE) for a surgery clerkship, assessing both faculty and materials costs. The OSCE was found to be more time consuming and expensive. Cost-cutting measures and guidelines to assist medical schools in selecting test type are…

Comparing Two Cooperative Small Group Formats Used with Physical Therapy and Medical Students

ERIC Educational Resources Information Center

D'Eon, Marcel; Proctor, Peggy; Reeder, Bruce

2007-01-01

This study compared "Structured Controversy" (a semi-formal debate like small group activity) with a traditional open discussion format for medical and physical therapy students. We found that those students who had participated in Structured Controversy changed their personal opinion on the topic more than those who were in the Open Discussion…

Gender Differences in Structured Risk Assessment: Comparing the Accuracy of Five Instruments

ERIC Educational Resources Information Center

Coid, Jeremy; Yang, Min; Ullrich, Simone; Zhang, Tianqiang; Sizmur, Steve; Roberts, Colin; Farrington, David P.; Rogers, Robert D.

2009-01-01

Structured risk assessment should guide clinical risk management, but it is uncertain which instrument has the highest predictive accuracy among men and women. In the present study, the authors compared the Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991, 2003); the Historical, Clinical, Risk Management-20 (HCR-20; C. D. Webster, K. S.…

Preliminary design optimization of joined-wing aircraft

NASA Technical Reports Server (NTRS)

Gallman, John W.; Kroo, Ilan M.; Smith, Stephen C.

1990-01-01

The joined wing is an innovative aircraft configuration that has a its tail connected to the wing forming a diamond shape in both top and plan view. This geometric arrangement utilizes the tail for both pitch control and as a structural support for the wing. Several researchers have studied this configuration and predicted significant reductions in trimmed drag or structural weight when compared with a conventional T-tail configuration. Kroo et al. compared the cruise drag of joined wings with conventional designs of the same lifting-surface area and structural weight. This study showed an 11 percent reduction in cruise drag for the lifting system of a joined wing. Although this reduction in cruise drag is significant, a complete design study is needed before any economic savings can be claimed for a joined-wing transport. Mission constraints, such as runway length, could increase the wing area and eliminate potential drag savings. Since other design codes do not accurately represent the interaction between structures and aerodynamics for joined wings, we developed a new design code for this study. The aerodynamic and structural analyses in this study are significantly more sophisticated than those used in most conventional design codes. This sophistication was needed to predict the aerodynamic interference between the wing and tail and the stresses in the truss-like structure. This paper describes these analysis methods, discusses some problems encountered when applying the numerical optimizer NPSOL, and compares optimum joined wings with conventional aircraft on the basis of cruise drag, lifting surface weight, and direct operating cost (DOC).

Detection of stable community structures within gut microbiota co-occurrence networks from different human populations.

PubMed

Jackson, Matthew A; Bonder, Marc Jan; Kuncheva, Zhana; Zierer, Jonas; Fu, Jingyuan; Kurilshikov, Alexander; Wijmenga, Cisca; Zhernakova, Alexandra; Bell, Jordana T; Spector, Tim D; Steves, Claire J

2018-01-01

Microbes in the gut microbiome form sub-communities based on shared niche specialisations and specific interactions between individual taxa. The inter-microbial relationships that define these communities can be inferred from the co-occurrence of taxa across multiple samples. Here, we present an approach to identify comparable communities within different gut microbiota co-occurrence networks, and demonstrate its use by comparing the gut microbiota community structures of three geographically diverse populations. We combine gut microbiota profiles from 2,764 British, 1,023 Dutch, and 639 Israeli individuals, derive co-occurrence networks between their operational taxonomic units, and detect comparable communities within them. Comparing populations we find that community structure is significantly more similar between datasets than expected by chance. Mapping communities across the datasets, we also show that communities can have similar associations to host phenotypes in different populations. This study shows that the community structure within the gut microbiota is stable across populations, and describes a novel approach that facilitates comparative community-centric microbiome analyses.

A comparative study of the inner ear structures of artiodactyls and early cetaceans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klingshirn, M.A.; Luo, Z.

1994-12-31

It has been suggested that the order Cetacea (whales and porpoises) are closely related to artiodactyls, even-hoofed ungulate mammals such as the pig and cow. Paleontological and molecular data strongly supports this concept of phylogenetic relationships. In a study of DNA sequences of two mitochondrial ribosomal gene segments of cetaceans, the artiodactyls were found to be closest related to Cetaceans. These well accepted studies on the phylogenetic affinities of artiodactyls and cetaceans cause us to conduct a comparative study of the bony structure of the inner ear of these two taxa.

Visualization and manipulating the image of a formal data structure (FDS)-based database

NASA Astrophysics Data System (ADS)

Verdiesen, Franc; de Hoop, Sylvia; Molenaar, Martien

1994-08-01

A vector map is a terrain representation with a vector-structured geometry. Molenaar formulated an object-oriented formal data structure for 3D single valued vector maps. This FDS is implemented in a database (Oracle). In this study we describe a methodology for visualizing a FDS-based database and manipulating the image. A data set retrieved by querying the database is converted into an import file for a drawing application. An objective of this study is that an end-user can alter and add terrain objects in the image. The drawing application creates an export file, that is compared with the import file. Differences between these files result in updating the database which involves checks on consistency. In this study Autocad is used for visualizing and manipulating the image of the data set. A computer program has been written for the data exchange and conversion between Oracle and Autocad. The data structure of the FDS is compared to the data structure of Autocad and the data of the FDS is converted into the structure of Autocad equal to the FDS.

Personality structure in the domestic cat (Felis silvestris catus), Scottish wildcat (Felis silvestris grampia), clouded leopard (Neofelis nebulosa), snow leopard (Panthera uncia), and African lion (Panthera leo): a comparative study.

PubMed

Gartner, Marieke Cassia; Powell, David M; Weiss, Alexander

2014-11-01

Although the study of nonhuman personality has increased in the last decade, there are still few studies on felid species, and the majority focus on domestic cats. We assessed the structure of personality and its reliability in five felids-domestic cats, clouded leopards, snow leopards, African lions, and previous data on Scottish wildcats-and compared the results. In addition to the benefits of understanding more about this taxon, comparative studies of personality structure have the potential to provide information on evolutionary relationships among closely related species. Each of the species studied was found to have three factors of personality. Scottish wildcats' factors were labeled Dominance, Agreeableness, and Self Control; domestic cats' factors were Dominance, Impulsiveness, and Neuroticism; clouded leopards' factors were Dominance/Impulsiveness, Agreeableness/Openness, and Neuroticism; snow leopards' factors were Dominance, Impulsiveness/Openness, and Neuroticism; and African lions' factors were Dominance, Impulsiveness, and Neuroticism. The Neuroticism and Impulsiveness factors were similar, as were two of the Dominance factors. A taxon-level personality structure also showed three similar factors. Age and sex effects are also discussed. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

History, anatomical nomenclature, comparative anatomy and functions of the hippocampal formation.

PubMed

El-Falougy, H; Benuska, J

2006-01-01

The complex structures in the cerebral hemispheres is included under one term, the limbic system. Our conception of this system and its special functions rises from the comparative neuroanatomical and neurophysiological studies. The components of the limbic system are the hippocampus, gyrus parahippocampalis, gyrus dentatus, gyrus cinguli, corpus amygdaloideum, nuclei anteriores thalami, hypothalamus and gyrus paraterminalis Because of its unique macroscopic and microscopic structure, the hippocampus is a conspicuous part of the limbic system. During phylogenetic development, the hippocampus developed from a simple cortical plate in amphibians into complex three-dimensional convoluted structure in mammals. In the last few decades, structures of the limbic system were extensively studied. Attention was directed to the physiological functions and pathological changes of the hippocampus. Experimental studies proved that the hippocampus has a very important role in the process of learning and memory. Another important functions of the hippocampus as a part of the limbic system is its role in regulation of sexual and emotional behaviour. The term "hippocampal formation" is defined as the complex of six structures: gyrus dentatus, hippocampus proprius, subiculum proprium, presubiculum, parasubiculum and area entorhinalis In this work we attempt to present a brief review of knowledge about the hippocampus from the point of view of history, anatomical nomenclature, comparative anatomy and functions (Tab. 1, Fig. 2, Ref. 33).

Structural adaptation of the subunit interface of oligomeric thermophilic and hyperthermophilic enzymes.

PubMed

Maugini, Elisa; Tronelli, Daniele; Bossa, Francesco; Pascarella, Stefano

2009-04-01

Enzymes from thermophilic and, particularly, from hyperthermophilic organisms are surprisingly stable. Understanding of the molecular origin of protein thermostability and thermoactivity attracted the interest of many scientist both for the perspective comprehension of the principles of protein structure and for the possible biotechnological applications through application of protein engineering. Comparative studies at sequence and structure levels were aimed at detecting significant differences of structural parameters related to protein stability between thermophilic and hyperhermophilic structures and their mesophilic homologs. Comparative studies were useful in the identification of a few recurrent themes which the evolution utilized in different combinations in different protein families. These studies were mostly carried out at the monomer level. However, maintenance of a proper quaternary structure is an essential prerequisite for a functional macromolecule. At the environmental temperatures experienced typically by hyper- and thermophiles, the subunit interactions mediated by the interface must be sufficiently stable. Our analysis was therefore aimed at the identification of the molecular strategies adopted by evolution to enhance interface thermostability of oligomeric enzymes. The variation of several structural properties related to protein stability were tested at the subunit interfaces of thermophilic and hyperthermophilic oligomers. The differences of the interface structural features observed between the hyperthermophilic and thermophilic enzymes were compared with the differences of the same properties calculated from pairwise comparisons of oligomeric mesophilic proteins contained in a reference dataset. The significance of the observed differences of structural properties was measured by a t-test. Ion pairs and hydrogen bonds do not vary significantly while hydrophobic contact area increases specially in hyperthermophilic interfaces. Interface compactness also appears to increase in the hyperthermophilic proteins. Variations of amino acid composition at the interfaces reflects the variation of the interface properties.

The use of amphipols for solution NMR studies of membrane proteins: advantages and constraints as compared to other solubilizing media.

PubMed

Planchard, Noelya; Point, Élodie; Dahmane, Tassadite; Giusti, Fabrice; Renault, Marie; Le Bon, Christel; Durand, Grégory; Milon, Alain; Guittet, Éric; Zoonens, Manuela; Popot, Jean-Luc; Catoire, Laurent J

2014-10-01

Solution-state nuclear magnetic resonance studies of membrane proteins are facilitated by the increased stability that trapping with amphipols confers to most of them as compared to detergent solutions. They have yielded information on the state of folding of the proteins, their areas of contact with the polymer, their dynamics, water accessibility, and the structure of protein-bound ligands. They benefit from the diversification of amphipol chemical structures and the availability of deuterated amphipols. The advantages and constraints of working with amphipols are discussed and compared to those associated with other non-conventional environments, such as bicelles and nanodiscs.

Simulation Study on Fit Indexes in CFA Based on Data with Slightly Distorted Simple Structure

ERIC Educational Resources Information Center

Beauducel, Andre; Wittmann, Werner W.

2005-01-01

Fit indexes were compared with respect to a specific type of model misspecification. Simple structure was violated with some secondary loadings that were present in the true models that were not specified in the estimated models. The c2 test, Comparative Fit Index, Goodness-of-Fit Index, Incremental Fit Index, Nonnormed Fit Index, root mean…

Comparing Factor Structures of Adolescent Psychopathology

ERIC Educational Resources Information Center

Verona, Edelyn; Javdani, Shabnam; Sprague, Jenessa

2011-01-01

Research on the structure of adolescent psychopathology can provide information on broad factors that underlie different forms of maladjustment in youths. Multiple studies from the literature on adult populations suggest that 2 factors, Internalizing and Externalizing, meaningfully comprise the factor structure of adult psychopathology (e.g.,…

Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing

NASA Astrophysics Data System (ADS)

Huan, Z.; Fratila-Apachitei, L. E.; Apachitei, I.; Duszczyk, J.

2014-02-01

The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing.

PubMed

Huan, Z; Fratila-Apachitei, L E; Apachitei, I; Duszczyk, J

2014-02-07

The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

Formation of periodic surface structures on dielectrics after irradiation with laser beams of spatially variant polarisation: a comparative study

NASA Astrophysics Data System (ADS)

Papadopoulos, Antonis; Skoulas, Evangelos; Tsibidis, George D.; Stratakis, Emmanuel

2018-02-01

A comparative study is performed to explore the periodic structure formation upon intense femtosecond-pulsed irradiation of dielectrics with radially and azimuthally polarised beams. Laser conditions have been selected appropriately to produce excited carriers with densities below the optical breakdown threshold in order to highlight the role of phase transitions in surface modification mechanisms. The frequency of the laser-induced structures is calculated based on a theoretical model that comprises estimation of electron density excitation, heat transfer, relaxation processes, and hydrodynamics-related mass transport. The influence of the laser wavelength in the periodicity of the structures is also unveiled. The decreased energy absorption for azimuthally polarised beams yields periodic structures with smaller frequencies which are more pronounced as the number of laser pulses applied to the irradiation spot increases. Similar results are obtained for laser pulses of larger photon energy and higher fluences. All induced periodic structures are oriented parallel to the laser beam polarisation.

Experimental Study on the Fire Properties of Nitrocellulose with Different Structures

PubMed Central

Wei, Ruichao; He, Yaping; Liu, Jiahao; He, Yu; Mi, Wenzhong; Yuen, Richard; Wang, Jian

2017-01-01

In order to ensure the safety of inflammable and explosive chemical substance such as nitrocellulose (NC) mixtures in the process of handing, storage, and usage, it is necessary to obtain the fire properties of NC with different exterior structures. In present study, fire properties of two commonly used nitrocelluloses with soft fiber structure and white chip structure were investigated by scanning electron microscope (SEM) and the ISO 5660 cone calorimeter. Experimental findings revealed that the most important fire properties such as ignition time, mass loss rate and ash content exhibited significant differences between the two structures of NC. Compared with the soft fiber NC, chip NC possesses a lower fire hazard, and its heat release rate intensity (HRRI) is mainly affected by the sample mass. In addition, oxygen consumption (OC) calorimetry method was compared with thermal chemistry (TC) method based on stoichiometry for HRRI calculation. HRRI results of NC with two structures obtained by these two methods showed a good consistency. PMID:28772675

Structured reports of videofluoroscopic swallowing studies have the potential to improve overall report quality compared to free text reports.

PubMed

Schoeppe, Franziska; Sommer, Wieland H; Haack, Mareike; Havel, Miriam; Rheinwald, Marika; Wechtenbruch, Juliane; Fischer, Martin R; Meinel, Felix G; Sabel, Bastian O; Sommer, Nora N

2018-01-01

To compare free text (FTR) and structured reports (SR) of videofluoroscopic swallowing studies (VFSS) and evaluate satisfaction of referring otolaryngologists and speech therapists. Both standard FTR and SR of 26 patients with VFSS were acquired. A dedicated template focusing on oropharyngeal phases was created for SR using online software with clickable decision-trees and concomitant generation of semantically structured reports. All reports were evaluated regarding overall quality and content, information extraction and clinical decision support (10-point Likert scale (0 = I completely disagree, 10 = I completely agree)). Two otorhinolaryngologists and two speech therapists evaluated FTR and SR. SR received better ratings than FTR in all items. SR were perceived to contain more details on the swallowing phases (median rating: 10 vs. 5; P < 0.001), penetration and aspiration (10 vs. 5; P < 0.001) and facilitated information extraction compared to FTR (10 vs. 4; P < 0.001). Overall quality was rated significantly higher in SR than FTR (P < 0.001). SR of VFSS provide more detailed information and facilitate information extraction. SR better assist in clinical decision-making, might enhance the quality of the report and, thus, are recommended for the evaluation of VFSS. • Structured reports on videofluoroscopic exams of deglutition lead to improved report quality. • Information extraction is facilitated when using structured reports based on decision trees. • Template-based reports add more value to clinical decision-making than free text reports. • Structured reports receive better ratings by speech therapists and otolaryngologists. • Structured reports on videofluoroscopic exams may improve the comparability between exams.

Function-Oriented Synthesis: How to Design Simplified Analogues of Antibacterial Nucleoside Natural Products?

PubMed

Ichikawa, Satoshi

2016-06-01

It is important to pursue function-oriented synthesis (FOS), a strategy for the design of less structurally complex targets with comparable or superior activity that can be made in a practical manner, because compared to synthetic drugs, many biologically relevant natural products possess large and complex chemical structures that may restrict chemical modifications in a structure-activity relationship study. In this account, we describe recent efforts to simplify complex nucleoside natural products including caprazamycins. Considering the structure-activity relationship study with several truncated analogues, three types of simplified derivatives, namely, oxazolidine, isoxazolidine, and lactam-fused isoxazolidine-containing uridine derivatives, were designed and efficiently synthesized. These simplified derivatives have exhibited promising antibacterial activities. A significant feature of our studies is the rational and drastic simplification of the molecular architecture of caprazamycins. This study provides a novel strategy for the development of a new type of antibacterial agent effective against drug-resistant bacteria. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Important Questions of Comparative Studies in Asian Countries

ERIC Educational Resources Information Center

Pazyura, Natalia

2015-01-01

The issue of the "identity" of comparative education as a field of study or a discipline has been discussed for decades. Yet a kind of systematic structure that provides the basic principles for a coherent exposition of the field remains open. "Comparative education" is no longer conceived as an imaginary field's coherence but,…

Language Ability Predicts Cortical Structure and Covariance in Boys with Autism Spectrum Disorder.

PubMed

Sharda, Megha; Foster, Nicholas E V; Tryfon, Ana; Doyle-Thomas, Krissy A R; Ouimet, Tia; Anagnostou, Evdokia; Evans, Alan C; Zwaigenbaum, Lonnie; Lerch, Jason P; Lewis, John D; Hyde, Krista L

2017-03-01

There is significant clinical heterogeneity in language and communication abilities of individuals with Autism Spectrum Disorders (ASD). However, no consistent pathology regarding the relationship of these abilities to brain structure has emerged. Recent developments in anatomical correlation-based approaches to map structural covariance networks (SCNs), combined with detailed behavioral characterization, offer an alternative for studying these relationships. In this study, such an approach was used to study the integrity of SCNs of cortical thickness and surface area associated with language and communication, in 46 high-functioning, school-age children with ASD compared with 50 matched, typically developing controls (all males) with IQ > 75. Findings showed that there was alteration of cortical structure and disruption of fronto-temporal cortical covariance in ASD compared with controls. Furthermore, in an analysis of a subset of ASD participants, alterations in both cortical structure and covariance were modulated by structural language ability of the participants, but not communicative function. These findings indicate that structural language abilities are related to altered fronto-temporal cortical covariance in ASD, much more than symptom severity or cognitive ability. They also support the importance of better characterizing ASD samples while studying brain structure and for better understanding individual differences in language and communication abilities in ASD. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Epistemological Beliefs across Cultures: Critique and Analysis of Beliefs Structure Studies

ERIC Educational Resources Information Center

Chan, Kwok-wai; Elliott, Robert G.

2004-01-01

The findings of epistemological beliefs studies in North America, Hong Kong and Taiwan were compared and interpreted in terms of the different cultural contexts and methodologies used in the research studies. Based on cross culture analysis a hypothesis for the structure of epistemological beliefs was proposed. Implications were also drawn for…

Structural damping studies at cryogenic temperatures

NASA Technical Reports Server (NTRS)

Young, Clarence P., Jr.; Buehrle, Ralph D.

1994-01-01

Results of an engineering study to measure changes in structural damping properties of two cryogenic wind tunnel model systems and two metallic test specimens at cryogenic temperatures are presented. Data are presented which indicate overall, a trend toward reduced structural damping at cryogenic temperatures (-250 degrees F) when compared with room temperature damping properties. The study was focused on structures and materials used for model systems tested in the National Transonic Facility (NTF). The study suggests that the significant reductions in damping at extremely cold temperatures are most likely associated with changes in mechanical joint compliance damping rather than changes in material (solid) damping.

Comparative study of metallic silicide-germanide orthorhombic MnP systems.

PubMed

Connétable, Damien; Thomas, Olivier

2013-09-04

We present a comparative study of the structural, energetic, electronic and elastic properties of MX type MnP systems (where X=Si or Ge, and M=Pt, Pd or Ni) using first-principles calculations. The optimized ground state properties of these systems are in excellent agreement with the experimental values. A detailed comparative study of the elastic properties of polycrystalline structures is also presented. We analyze the relationship between the composition and the properties of the systems. Finally, we present the properties of NiSi1-xGex alloys. We show that these properties depend linearly on the Ge content of the alloy. This work has important consequences for semiconductor devices in which silicides, germanides and alloys thereof are used as contact materials.

The effects of design details on cost and weight of fuselage structures

NASA Technical Reports Server (NTRS)

Swanson, G. D.; Metschan, S. L.; Morris, M. R.; Kassapoglou, C.

1993-01-01

Crown panel design studies showing the relationship between panel size, cost, weight, and aircraft configuration are compared to aluminum design configurations. The effects of a stiffened sandwich design concept are also discussed. This paper summarizes the effect of a design cost model in assessing the cost and weight relationships for fuselage crown panel designs. Studies were performed using data from existing aircraft to assess the effects of different design variables on the cost and weight of transport fuselage crown panel design. Results show a strong influence of load levels, panel size, and material choices on the cost and weight of specific designs. A design tool being developed under the NASA ACT program is used in the study to assess these issues. The effects of panel configuration comparing postbuckled and buckle resistant stiffened laminated structure is compared to a stiffened sandwich concept. Results suggest some potential economy with stiffened sandwich designs for compression dominated structure with relatively high load levels.

Structural response of Caribbean dry forests to hurricane winds: a case study from Guanica Forest, Puerto Rico.

Treesearch

Skip J. Van Bloem; Ariel E. Lugo; Peter G. Murphy

2006-01-01

Tropical dry forests in the Caribbean have an uniquely short, shrubby structure with a high proportion of multiple-stemmed trees compared to dry forests elsewhere in the Neotropics. Previous studies have shown that this structure can arise without the loss of main stems from cutting, grazing, or other human intervention. The Caribbean has a high frequency of hurricanes...

Structural properties of ultrafine Ba-hexaferrite nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makovec, Darko, E-mail: Darko.Makovec@ijs.si; Primc, Darinka; Sturm, Saso

2012-12-15

Crystal structure of ultrafine Ba-hexaferrite (BaFe{sub 12}O{sub 19}) nanoparticles was studied using X-ray diffractometry (XRD), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDXS), X-ray absorption fine structure (XAFS), and Moessbauer spectroscopy (MS), to be compared to the structure of larger nanoparticles and the bulk. The nanoparticles were synthesized with hydrothermal treatment of an appropriate suspension of Ba and Fe hydroxides in the presence of a large excess of OH{sup -}. The ultrafine nanoparticles were formed in a discoid shape, {approx}10 nm wide and only {approx}3 nm thick, comparable to the size of the hexagonal unit cell in the c-direction.more » The HRTEM image analysis confirmed the hexaferrite structure, whereas EDXS showed the composition matching the BaFe{sub 12}O{sub 19} formula. XAFS and MS analyses showed considerable disorder of the structure, most probably responsible for the low magnetization. - Graphical abstract: Left: HREM image of an ultrafine Ba-hexaferrite nanoparticle (inset: TEM image of the nanoparticles); Right: the experimental HRTEM image is compared with calculated image and corresponding atomic model. Highlights: Black-Right-Pointing-Pointer Crystal structure of ultrafine Ba-hexaferrite (BaFe{sub 12}O{sub 19}) nanoparticles was compared to the structure of the bulk. Black-Right-Pointing-Pointer Thickness the discoid nanoparticles was comparable to the size of the hexagonal unit cell in the c-direction. Black-Right-Pointing-Pointer Considerable disorder of the nanoparticles' structure is most probably responsible for their low magnetization.« less

Electro Optical Properties of Copolymer Blends: Lasing, Electroluminescence and Photophysics

DTIC Science & Technology

2006-04-15

conjugated main chain structures with high photoluminescent and electroluminescent quantum yields. The structures incorporated fluorene containing moieties...The systems studied focused on novel conjugated main chain structures with high photoluminescent and electroluminescent quantum yields. The structures...the quantum efficient fluorine group. The properties of segmented copolymers that incorporate fluorenes were compared to the homo-PPV type systems

Blood flow structure in patients with coronary heart disease

NASA Astrophysics Data System (ADS)

Malinova, Lidia I.; Simonenko, Georgy V.; Denisova, Tatyana P.; Tuchin, Valery V.

2007-05-01

Blood flow structure was studied by PC integrated video camera with following slide by slide analysis. Volumetric blood flow velocity was supporting on constant level (1 ml/h). Silicone tube of diameter comparable with coronary arteries diameter was used as vessel model. Cell-cell interactions were studied under glucose and anticoagulants influence. Increased adhesiveness of blood cells to tube walls was revealed in patient with coronary heart disease (CHD) compare to practically healthy persons (PHP). In patients with stable angina pectoris of high functional class and patients with AMI shear stress resistant erythrocyte aggregates were predominating in blood flow structure up to microclots formation. Clotting and erythrocytes aggregation increase as response to glucose solution injection, sharply defined in patients with CHD. Heparin injection (10 000 ED) increased linear blood flow velocity both in patients with CHD and PHP. After compare our results with other author's data we can consider that method used in our study is sensible enough to investigate blood flow structure violations in patients with CHD and PHP. Several differences of cell-cell interaction in flow under glucose and anticoagulant influence were found out in patients with CHD and PHP.

Analytical characterization of recombinant hCG and comparative studies with reference product.

PubMed

Thennati, Rajamannar; Singh, Sanjay Kumar; Nage, Nitin; Patel, Yena; Bose, Sandip Kumar; Burade, Vinod; Ranbhor, Ranjit Sudhakar

2018-01-01

Regulatory agencies recommend a stepwise approach for demonstrating biosimilarity between a proposed biosimilar and reference biological product emphasizing for functional and structural characterization to trace if there is any difference which may impact safety and efficacy. We studied the comparative structural and biological attributes of recombinant human chorionic gonadotropin (rhCG), SB005, with reference product, Ovidrel ® and Ovitrelle ® . Recombiant hCG was approved in 2000 by the US Food and Drug Administration for the induction of final follicular maturation, early luteinization in infertile women as part of assisted reproductive technology program. It is also indicated for the induction of ovulation and pregnancy in ovulatory infertile patients whose cause of infertility is not due to ovarian failure. Primary structure was studied by intact mass analysis, peptide fingerprinting, peptide mass fingerprinting and sequence coverage analysis. Higher order structure was studied by circular dichroism, ultraviolet-visible spectroscopy, fluorescence spectroscopy, and disulfide bridge analysis. Different isoforms of reference product and SB005 were identified using capillary isoelectric focusing and capillary zone electrophoresis. Glycosylation was studied by N-glycan mapping using LC-ESI-MS, point of glycosylation, released glycan analysis using ultra performance liquid chromatography and sialic acid analysis. Product related impurities such as oligomer content analysis and oxidized impurities were studied using size exclusion chromatography and reverse phase high performance liquid chromatography, respectively. Biological activity in term of potency of reference product and SB005 was studied by in vivo analysis. In this study we have compared analytical similarity of recombinant rhCG (SB005) produced at Sun Pharmaceuticals with the reference product with respect to its primary, higher order structure, isoforms, charge variants, glycosylation, sialyation pattern, pharmacodynamic and in vivo efficacy. Our studies show that the in house produced rhCG has a high degree of structural and functional similarity with the reference product available in the market.

Analytical characterization of recombinant hCG and comparative studies with reference product

PubMed Central

Thennati, Rajamannar; Singh, Sanjay Kumar; Nage, Nitin; Patel, Yena; Bose, Sandip Kumar; Burade, Vinod

2018-01-01

Introduction Regulatory agencies recommend a stepwise approach for demonstrating biosimilarity between a proposed biosimilar and reference biological product emphasizing for functional and structural characterization to trace if there is any difference which may impact safety and efficacy. We studied the comparative structural and biological attributes of recombinant human chorionic gonadotropin (rhCG), SB005, with reference product, Ovidrel® and Ovitrelle®. Recombiant hCG was approved in 2000 by the US Food and Drug Administration for the induction of final follicular maturation, early luteinization in infertile women as part of assisted reproductive technology program. It is also indicated for the induction of ovulation and pregnancy in ovulatory infertile patients whose cause of infertility is not due to ovarian failure. Materials and methods Primary structure was studied by intact mass analysis, peptide fingerprinting, peptide mass fingerprinting and sequence coverage analysis. Higher order structure was studied by circular dichroism, ultraviolet-visible spectroscopy, fluorescence spectroscopy, and disulfide bridge analysis. Different isoforms of reference product and SB005 were identified using capillary isoelectric focusing and capillary zone electrophoresis. Glycosylation was studied by N-glycan mapping using LC-ESI-MS, point of glycosylation, released glycan analysis using ultra performance liquid chromatography and sialic acid analysis. Product related impurities such as oligomer content analysis and oxidized impurities were studied using size exclusion chromatography and reverse phase high performance liquid chromatography, respectively. Biological activity in term of potency of reference product and SB005 was studied by in vivo analysis. Results and Conclusion In this study we have compared analytical similarity of recombinant rhCG (SB005) produced at Sun Pharmaceuticals with the reference product with respect to its primary, higher order structure, isoforms, charge variants, glycosylation, sialyation pattern, pharmacodynamic and in vivo efficacy. Our studies show that the in house produced rhCG has a high degree of structural and functional similarity with the reference product available in the market. PMID:29430170

Restructuring the High School: The Renaissance Program.

ERIC Educational Resources Information Center

Donavel, David F.

Based on the premise that deficiencies in student learning are inherent byproducts of the traditional school structure, this study compares the effects of an experimental curriculum program on student learning with its traditional structural counterpart. The traditional school structure is characterized by a heavy teacher workload, segmented…

COMPARATIVE STUDY OF THREE FUNDAMENTAL ORGANIC COMPOUNDS OF CHAIN STRUCTURE OF THREE RINGS An approach based in the molecular descriptors of the DFT (Density Functional Theory)

NASA Astrophysics Data System (ADS)

Leon, Neira B. Oscar; Fabio, Mejía Elio; Elizabeth, y. Rincón B.

2008-04-01

The organic molecules of a chain structure containing phenyl, oxazole and oxadiazole rings are used in different combinations as active media for tunable lasers. From this viewpoint, we focused in the theoretical study of organic compounds of three rings, which have similar optical properties (fluorescence and laser properties). The main goal of this study is to compare the electronic structure through the analysis of molecular global descriptors defined in the DFT framework of2-[2-X-phenyl]-5-phenyl-1,3-Oxazole, 2-[2-X-phenyl]-5-phenyl-1,3,4-Oxadiazole, and 2-[2-X-phenyl]-5-phenyl-furane with X = H, F and Cl. The basis set used was 6-31G+(d).

Comparison of onboard low-field magnetic resonance imaging versus onboard computed tomography for anatomy visualization in radiotherapy.

PubMed

Noel, Camille E; Parikh, Parag J; Spencer, Christopher R; Green, Olga L; Hu, Yanle; Mutic, Sasa; Olsen, Jeffrey R

2015-01-01

Onboard magnetic resonance imaging (OB-MRI) for daily localization and adaptive radiotherapy has been under development by several groups. However, no clinical studies have evaluated whether OB-MRI improves visualization of the target and organs at risk (OARs) compared to standard onboard computed tomography (OB-CT). This study compared visualization of patient anatomy on images acquired on the MRI-(60)Co ViewRay system to those acquired with OB-CT. Fourteen patients enrolled on a protocol approved by the Institutional Review Board (IRB) and undergoing image-guided radiotherapy for cancer in the thorax (n = 2), pelvis (n = 6), abdomen (n = 3) or head and neck (n = 3) were imaged with OB-MRI and OB-CT. For each of the 14 patients, the OB-MRI and OB-CT datasets were displayed side-by-side and independently reviewed by three radiation oncologists. Each physician was asked to evaluate which dataset offered better visualization of the target and OARs. A quantitative contouring study was performed on two abdominal patients to assess if OB-MRI could offer improved inter-observer segmentation agreement for adaptive planning. In total 221 OARs and 10 targets were compared for visualization on OB-MRI and OB-CT by each of the three physicians. The majority of physicians (two or more) evaluated visualization on MRI as better for 71% of structures, worse for 10% of structures, and equivalent for 14% of structures. 5% of structures were not visible on either. Physicians agreed unanimously for 74% and in majority for > 99% of structures. Targets were better visualized on MRI in 4/10 cases, and never on OB-CT. Low-field MR provides better anatomic visualization of many radiotherapy targets and most OARs as compared to OB-CT. Further studies with OB-MRI should be pursued.

Interpretation of normal anatomic structures on chest radiography: Comparison of Fuji Computed Radiography (FCR) 5501D with FCR 5000 and screen‐film system

PubMed Central

Nakashima, Kazuaki; Ashizawa, Kazuto; Ochi, Makoto; Hashmi, Rashid; Hayashi, Kuniaki; Gotoh, Shinichi; Honda, Sumihisa; Igarashi, Akito; Komaki, Takao

2003-01-01

The purpose of this study was to investigate the usefulness of Fuji Computed Radiography (FCR) 5501D by comparing it with FCR 5000 and a screen‐film system (S/F). Posteroanterior chest radiographs often patients with no abnormality on chest CT scans were obtained with FCR 5501D, FCR 5000, and S/F. Six observers (three radiologists and three radio‐technologists) evaluated the visibility of nine normal anatomic structures (including lungs, soft tissue, and bones) and overall visibility on each image. Observers scored using a five‐point scale on each structure. FCR 5000 showed a significantly higher score in soft tissue and bone structures, and overall visibility compared with S/F, but, there was no significant difference between them in the visibility of all four normal lung structures. Compared with S/F, the score for FCR 5501D was higher in eight of the nine normal structures, including three of the four lung structures (unobscured lung, retrocardiac lung, and subdiaphragmatic lung), and overall visibility. Compared with FCR 5000, the score for FCR 5501D was higher in three normal structures, including two of the four lung structures (unobscured lung and subdiaphragmatic lung), and overall visibility. FCR 5501D was the best among the three techniques to visualize normal anatomic structures, particularly the obscured and unobscured lung. © 2003 American College of Medical Physics. PACS number(s): 87.57.–s, 87.62.+n PMID:12540822

Sparse matrix methods research using the CSM testbed software system

NASA Technical Reports Server (NTRS)

Chu, Eleanor; George, J. Alan

1989-01-01

Research is described on sparse matrix techniques for the Computational Structural Mechanics (CSM) Testbed. The primary objective was to compare the performance of state-of-the-art techniques for solving sparse systems with those that are currently available in the CSM Testbed. Thus, one of the first tasks was to become familiar with the structure of the testbed, and to install some or all of the SPARSPAK package in the testbed. A suite of subroutines to extract from the data base the relevant structural and numerical information about the matrix equations was written, and all the demonstration problems distributed with the testbed were successfully solved. These codes were documented, and performance studies comparing the SPARSPAK technology to the methods currently in the testbed were completed. In addition, some preliminary studies were done comparing some recently developed out-of-core techniques with the performance of the testbed processor INV.

Structural distortions due to missense mutations in human formylglycine-generating enzyme leading to multiple sulfatase deficiency.

PubMed

Meshach Paul, D; Chadah, Tania; Senthilkumar, B; Sethumadhavan, Rao; Rajasekaran, R

2017-11-03

The major candidate for multiple sulfatase deficiency is a defective formylglycine-generating enzyme (FGE). Though adequately produced, mutations in FGE stall the activation of sulfatases and prevent their activity. Missense mutations, viz. E130D, S155P, A177P, W179S, C218Y, R224W, N259I, P266L, A279V, C336R, R345C, A348P, R349Q and R349W associated with multiple sulfatase deficiency are yet to be computationally studied. Aforementioned mutants were initially screened through ws-SNPs&GO 3D program. Mutant R345C acquired the highest score, and hence was studied in detail. Discrete molecular dynamics explored structural distortions due to amino acid substitution. Therein, comparative analyses of wild type and mutant were carried out. Changes in structural contours were observed between wild type and mutant. Mutant had low conformational fluctuation, high atomic mobility and more compactness than wild type. Moreover, free energy landscape showed mutant to vary in terms of its conformational space as compared to wild type. Subsequently, wild type and mutant were subjected to single-model analyses. Mutant had lesser intra molecular interactions than wild type suggesting variations pertaining to its secondary structure. Furthermore, simulated thermal denaturation showed dissimilar pattern of hydrogen bond dilution. Effects of these variations were observed as changes in elements of secondary structure. Docking studies of mutant revealed less favourable binding energy towards its substrate as compared to wild type. Therefore, theoretical explanations for structural distortions of mutant R345C leading to multiple sulfatase deficiency were revealed. The protocol of the study could be useful to examine the effectiveness of pharmacological chaperones prior to experimental studies.

Neural Correlates of Verb Argument Structure Processing

PubMed Central

Thompson, Cynthia K.; Bonakdarpour, Borna; Fix, Stephen C.; Blumenfeld, Henrike K.; Parrish, Todd B.; Gitelman, Darren R.; Mesulam, M.-Marsel

2008-01-01

Neuroimaging and lesion studies suggest that processing of word classes, such as verbs and nouns, is associated with distinct neural mechanisms. Such studies also suggest that subcategories within these broad word class categories are differentially processed in the brain. Within the class of verbs, argument structure provides one linguistic dimension that distinguishes among verb exemplars, with some requiring more complex argument structure entries than others. This study examined the neural instantiation of verbs by argument structure complexity: one-, two-, and three-argument verbs. Stimuli of each type, along with nouns and pseudowords, were presented for lexical decision using an event-related functional magnetic resonance imaging design. Results for 14 young normal participants indicated largely overlapping activation maps for verbs and nouns, with no areas of significant activation for verbs compared to nouns, or vice versa. Pseudowords also engaged neural tissue overlapping with that for both word classes, with more widespread activation noted in visual, motor, and peri-sylvian regions. Examination of verbs by argument structure revealed activation of the supramarginal and angular gyri, limited to the left hemisphere only when verbs with two obligatory arguments were compared to verbs with a single argument. However, bilateral activation was noted when both two- and three-argument verbs were compared to one-argument verbs. These findings suggest that posterior peri-sylvian regions are engaged for processing argument structure information associated with verbs, with increasing neural tissue in the inferior parietal region associated with increasing argument structure complexity. These findings are consistent with processing accounts, which suggest that these regions are crucial for semantic integration. PMID:17958479

The influence of a yoga exercise program for young adults with intellectual disabilities.

PubMed

Hawkins, Brent L; Stegall, Joanna B; Weber, Madalyn F; Ryan, Joseph B

2012-07-01

Individuals with intellectual disabilities (ID) have an increased risk of obesity and are significantly less likely to engage in physical activity compared to their nondisabled peers. A growing body of research supports the physical and mental health benefits of yoga. While the benefits of yoga have been studied across a host of populations with varying ages and physical disabilities, no studies could be identified investigating the benefits of yoga for young adults with ID. This study investigated the impact of participating in yoga classes on the amount of exercise behavior and perception of physical exertion when compared to non-structured exercise sessions between two young adults with ID in a post-secondary education setting. A single subject multiple baseline research design was implemented across two young adults with mild ID to determine the effects of a yoga exercise class on frequency of exercise behavior and perception of physical exertion when compared to non-structured exercise sessions. Partial interval recording, the Eston-Parfitt curvilinear rating of perceived exertion scale, and the physical activity enjoyment scale were implemented to collect data on dependent variables and consumer satisfaction during each non-structured exercise session and each yoga class. indicated that percentage of exercise behavior and perceived exertion levels during yoga group exercise sharply increased with large effect sizes when compared to non-structured exercise sessions.

Gene-Transformation-Induced Changes in Chemical Functional Group Features and Molecular Structure Conformation in Alfalfa Plants Co-Expressing Lc-bHLH and C1-MYB Transcriptive Flavanoid Regulatory Genes: Effects of Single-Gene and Two-Gene Insertion.

PubMed

Heendeniya, Ravindra G; Yu, Peiqiang

2017-03-20

Alfalfa ( Medicago sativa L.) genotypes transformed with Lc-bHLH and Lc transcription genes were developed with the intention of stimulating proanthocyanidin synthesis in the aerial parts of the plant. To our knowledge, there are no studies on the effect of single-gene and two-gene transformation on chemical functional groups and molecular structure changes in these plants. The objective of this study was to use advanced molecular spectroscopy with multivariate chemometrics to determine chemical functional group intensity and molecular structure changes in alfalfa plants when co-expressing Lc-bHLH and C1-MYB transcriptive flavanoid regulatory genes in comparison with non-transgenic (NT) and AC Grazeland (ACGL) genotypes. The results showed that compared to NT genotype, the presence of double genes ( Lc and C1 ) increased ratios of both the area and peak height of protein structural Amide I/II and the height ratio of α-helix to β-sheet. In carbohydrate-related spectral analysis, the double gene-transformed alfalfa genotypes exhibited lower peak heights at 1370, 1240, 1153, and 1020 cm -1 compared to the NT genotype. Furthermore, the effect of double gene transformation on carbohydrate molecular structure was clearly revealed in the principal component analysis of the spectra. In conclusion, single or double transformation of Lc and C1 genes resulted in changing functional groups and molecular structure related to proteins and carbohydrates compared to the NT alfalfa genotype. The current study provided molecular structural information on the transgenic alfalfa plants and provided an insight into the impact of transgenes on protein and carbohydrate properties and their molecular structure's changes.

Nutritional evaluation of structured lipid containing omega 6 fatty acid synthesized from coconut oil in rats.

PubMed

Rao, Reena; Lokesh, Belur R

2003-06-01

Coconut oil is rich in medium chain fatty acids, but deficient in polyunsaturated fatty acids (PUFA). Structured lipids (SL) enriched with omega 6 PUFA were synthesized from coconut oil triglycerides by employing enzymatic acidolysis with free fatty acids obtained from safflower oil. Rats were fed a diet containing coconut oil, coconut oil-safflower oil blend (1:0.7 w/ w) or structured lipid at 10% levels for a period of 60 days. The SL lowered serum cholesterol levels by 10.3 and 10.5% respectively in comparison with those fed coconut oil and blended oil. Similarly the liver cholesterol levels were also decreased by 35.9 and 26.6% respectively in animals fed structured lipids when compared to those fed on coconut oil or the blended oil. Most of the decrease observed in serum cholesterol levels of animals fed structured lipids was found in LDL fraction. The triglyceride levels in serum showed a decrease by 17.5 and 17.4% while in the liver it was reduced by 45.8 and 23.5% in the structured lipids fed animals as compared to those fed coconut oil or blended oil respectively. Differential scanning calorimetric studies indicated that structured lipids had lower melting points and solid fat content when compared to coconut oil or blended oils. These studies indicated that enrichment of coconut oil triglycerides with omega 6 fatty acids lowers its solid fat content. The omega 6 PUFA enriched structured lipids also exhibited hypolipidemic activity.

Crystal structure analysis of Great Cormorant (Phalacrocorax carbo) Hemoglobin.

PubMed

Ganapathy, Jagadeesan; Palayam, Malathy; Pennathur, Gautam; Sanmargam, Aravindhan; Krishnasamy, Gunasekaran

2018-06-20

Hemoglobin (Hb) molecule consists of α2β2 dimers arranged in fashion having pseudo-222 symmetry. The subunits are composed of the specific functional prosthetic group "heme'' and a protein moiety "globin". Bird Hbs are functionally similar to mammalian Hbs and regulated by inositol pentaphosphate (IPP) but they are structurally dissimilar with mammalian Hbs in adaptation to vital environment such as high altitudes, high speed flights and oxygen affinity. The insufficient structural studies on avian Hbs limit us to understand their degree of adaptation to such critical environments. So far, detailed structural studies of bar-headed goose (BHG) and graylag goose (GLG) Hb structures were reported to expose their remarkable difference in molecular level adaptation. The striking contrasts to its close relative the bar headed goose, which lives at high altitude and capable of tolerating severe hypoxic environment is mainly due its structural features. The Great Cormorant (GCT) can fly and swim, the dual characteristic of GCT leads to study the details of adaptation of high oxygen affinity in avian species and to know about the role of amino acid substitutions at α1β1 interface, the crystal structure of Great cormorant is studied. The structure of GCT Hb has been solved at 3.5Å resolution and it is compared with the other high oxygen affinity Hb (graylag goose (GLG), bar headed goose (BHG) and human (HMN) hemoglobin) structures. To determine the crystal structure of Great Cormorant (GCT) Hemoglobin and to compare its three dimensional structure with other high and low oxygen affinity hemoglobin species to understand its characteristic features of high oxygen affinity. The GCT hemoglobin has been purified, crystallized and data sets were processed using iMosflm. The integrated data has been solved using Molecular replacement method using Graylag hemoglobin (1FAW) as the template. The structure refinement has been carried out using Refmac which reduced the Rwork and Rfree to 23% and 27% respectively. The structure has been deposited in Protein Data Bank with PDB code: 3WR1. The Great cormorant hemoglobin consists of 287 amino acids, two heme and one water molecule located in alpha heme site. The structure has been crystallized in a tetragonal system having half a molecule in the assymetric unit. In order to characterize the tertiary and quaternary structural differences, the structure of cormorant hemoglobin is compared with GLG, BHG and human Hb. The larger variation observed between GCT and human Hb indicates that GCT Hb differs remarkably from human. The α1β1 interface of Great cormorant Hb is similar to bar-headed goose Hb with few amino acid substitutions. It has been found that the interaction which is common among avian hemoglobins (α119 Pro- β55Leu) is altered by Ala 119 in GCT. This intra-dimer contact (α119 Pro - β 55 Leu) disruption leads to high oxygen affinity in BGH Hb. In cormorant, GLG and human the proline is unchanged but interestingly, in cormorant Hb, the β55 position was found to be Thr instead of Leu. Similar kind of substitutions (β 55 Leu - Ser) observed in Andean goose Hb structure leads to elevated oxygen affinity between Hb-O2. To our surprise, such type of substitution at β 55 (Thr) in cormorant Hb confirms that it is comparable with Andean goose Hb structure. Thus the sequence, structural differences at alpha, beta heme pocket and interface contacts confirms that GCT adopts high oxygen affinity conformation. The three dimensional structure of Great cormorant hemoglobin has been investigated to understand its unique structural features to adopt during hypoxia condition. The comparative studies of GCT's α, β heme pockets and the subunit interface with other Hbs reveal its similarities with goose Hbs. Also the loss of α119 - β55 contact in GCT and its unique mutation (Leu β55 Thr ) as in goose Hbs may play an important role in oxygen affinity. Thus by comparing the sequence and overall structural similarities with high and low oxygen affinity species, it appears that GCT has more possibilities to subsist with low oxygen demand. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Clinical comparative study with a large-area amorphous silicon flat-panel detector: image quality and visibility of anatomic structures on chest radiography.

PubMed

Fink, Christian; Hallscheidt, Peter J; Noeldge, Gerd; Kampschulte, Annette; Radeleff, Boris; Hosch, Waldemar P; Kauffmann, Günter W; Hansmann, Jochen

2002-02-01

The objective of this study was to compare clinical chest radiographs of a large-area, flat-panel digital radiography system and a conventional film-screen radiography system. The comparison was based on an observer preference study of image quality and visibility of anatomic structures. Routine follow-up chest radiographs were obtained from 100 consecutive oncology patients using a large-area, amorphous silicon flat-panel detector digital radiography system (dose equivalent to a 400-speed film system). Hard-copy images were compared with previous examinations of the same individuals taken on a conventional film-screen system (200-speed). Patients were excluded if changes in the chest anatomy were detected or if the time interval between the examinations exceeded 1 year. Observer preference was evaluated for the image quality and the visibility of 15 anatomic structures using a five-point scale. Dose measurements with a chest phantom showed a dose reduction of approximately 50% with the digital radiography system compared with the film-screen radiography system. The image quality and the visibility of all but one anatomic structure of the images obtained with the digital flat-panel detector system were rated significantly superior (p < or = 0.0003) to those obtained with the conventional film-screen radiography system. The image quality and visibility of anatomic structures on the images obtained by the flat-panel detector system were perceived as equal or superior to the images from conventional film-screen chest radiography. This was true even though the radiation dose was reduced approximately 50% with the digital flat-panel detector system.

The Relative Effects of Alternative Learning Structures on Attitudes and Achievements.

ERIC Educational Resources Information Center

Carifio, James

This study compared two learning structures for an introductory course in tests and measurements in terms of their relative effects on attitudes and achievement. The first structure represented a functionally arranged instructional sequence (FAIS). The second represented a psychologically arranged instructional sequence (PAIS). The instructional…

Measuring Learning in Serious Games: A Case Study with Structural Assessment

ERIC Educational Resources Information Center

Wouters, Pieter; van der Spek, Erik D.; van Oostendorp, Herre

2011-01-01

The effectiveness of serious games is often measured with verbal assessment. As an alternative we propose Pathfinder structural assessment (defined as measuring the learners' knowledge organization and compare this with a referent structure) which comprises three steps: knowledge elicitation, knowledge representation and knowledge evaluation. We…

A Comparative Study of Iranian and Japanese English Teachers' Demotivational Factors

ERIC Educational Resources Information Center

Baniasad-Azad, Somayeh; Ketabi, Saeed

2013-01-01

This study examined demotivational factors among Iranian and Japanese college teachers of English. To achieve the purpose, the study used a 35-item questionnaire and semi-structured interviews. The results were compared with the similar study in Japan by Sugino (2010). The findings of the study revealed that Iranian and Japanese lecturers are much…

2D- and 3D-quantitative structure-activity relationship studies for a series of phenazine N,N'-dioxide as antitumour agents.

PubMed

Cunha, Jonathan Da; Lavaggi, María Laura; Abasolo, María Inés; Cerecetto, Hugo; González, Mercedes

2011-12-01

Hypoxic regions of tumours are associated with increased resistance to radiation and chemotherapy. Nevertheless, hypoxia has been used as a tool for specific activation of some antitumour prodrugs, named bioreductive agents. Phenazine dioxides are an example of such bioreductive prodrugs. Our 2D-quantitative structure activity relationship studies established that phenazine dioxides electronic and lipophilic descriptors are related to survival fraction in oxia or in hypoxia. Additionally, statistically significant models, derived by partial least squares, were obtained between survival fraction in oxia and comparative molecular field analysis standard model (r² = 0.755, q² = 0.505 and F = 26.70) or comparative molecular similarity indices analysis-combined steric and electrostatic fields (r² = 0.757, q² = 0.527 and F = 14.93), and survival fraction in hypoxia and comparative molecular field analysis standard model (r² = 0.736, q² = 0.521 and F = 18.63) or comparative molecular similarity indices analysis-hydrogen bond acceptor field (r² = 0.858, q² = 0.737 and F = 27.19). Categorical classification was used for the biological parameter selective cytotoxicity emerging also good models, derived by soft independent modelling of class analogy, with both comparative molecular field analysis standard model (96% of overall classification accuracy) and comparative molecular similarity indices analysis-steric field (92% of overall classification accuracy). 2D- and 3D-quantitative structure-activity relationships models provided important insights into the chemical and structural basis involved in the molecular recognition process of these phenazines as bioreductive agents and should be useful for the design of new structurally related analogues with improved potency. © 2011 John Wiley & Sons A/S.

The Structure of Cognitive Abilities in Youths with Manic Symptoms: A Factorial Invariance Study

ERIC Educational Resources Information Center

Beaujean, A. Alexander; Freeman, Megan Joseph; Youngstrom, Eric; Carlson, Gabrielle

2012-01-01

This study compared the structure of cognitive ability (specifically, verbal/crystallized ["Gc"] and visual-spatial ability ["Gv"]), as measured in the Wechsler Intelligence Scale for Children, in youth with manic symptoms with a nationally representative group of similarly aged youth. Multigroup confirmatory factor analysis…

Developing a Multiplexed Quantitative Cross-Linking Mass Spectrometry Platform for Comparative Structural Analysis of Protein Complexes.

PubMed

Yu, Clinton; Huszagh, Alexander; Viner, Rosa; Novitsky, Eric J; Rychnovsky, Scott D; Huang, Lan

2016-10-18

Cross-linking mass spectrometry (XL-MS) represents a recently popularized hybrid methodology for defining protein-protein interactions (PPIs) and analyzing structures of large protein assemblies. In particular, XL-MS strategies have been demonstrated to be effective in elucidating molecular details of PPIs at the peptide resolution, providing a complementary set of structural data that can be utilized to refine existing complex structures or direct de novo modeling of unknown protein structures. To study structural and interaction dynamics of protein complexes, quantitative cross-linking mass spectrometry (QXL-MS) strategies based on isotope-labeled cross-linkers have been developed. Although successful, these approaches are mostly limited to pairwise comparisons. In order to establish a robust workflow enabling comparative analysis of multiple cross-linked samples simultaneously, we have developed a multiplexed QXL-MS strategy, namely, QMIX (Quantitation of Multiplexed, Isobaric-labeled cross (X)-linked peptides) by integrating MS-cleavable cross-linkers with isobaric labeling reagents. This study has established a new analytical platform for quantitative analysis of cross-linked peptides, which can be directly applied for multiplexed comparisons of the conformational dynamics of protein complexes and PPIs at the proteome scale in future studies.

A descriptive study of patient satisfaction and the structural factors of Norwegian intensive care nursing.

PubMed

Johannessen, Gudrun; Eikeland, Anne; Stubberud, Dag-Gunnar; Fagerstöm, Lisbeth

2011-10-01

The aim of this study was to describe patient satisfaction with nursing care in three different Norwegian Coronary Intensive Care Units and compare the results with other structural factors such as nursing competence, skill-mix, clinical experience, nurse to patient ratio and number of beds. A descriptive and comparative design was employed and 150 patients at three Coronary Intensive Care Units were included. Patient satisfaction data was collected using the Intensive Nursing Care Quality Instrument (59 items). The data collected was comprised of two parts: a questionnaire and information on the structural factors of the organisational structure. The data was analysed using descriptive statistics. Patients expressed overall satisfaction with the nursing care. No clear association was found between patient satisfaction and nursing competence, skill-mix, clinical experience, nurse to patient ratio and number of beds. When comparing results between units, significant differences were seen for 17 out of 46 questions. The results provide insight into how critical care staffing and skill-mix affect patient satisfaction and guide future nursing research in this subject area. Copyright © 2011. Published by Elsevier Ltd.

Molecular determinants of enzyme cold adaptation: comparative structural and computational studies of cold- and warm-adapted enzymes.

PubMed

Papaleo, Elena; Tiberti, Matteo; Invernizzi, Gaetano; Pasi, Marco; Ranzani, Valeria

2011-11-01

The identification of molecular mechanisms underlying enzyme cold adaptation is a hot-topic both for fundamental research and industrial applications. In the present contribution, we review the last decades of structural computational investigations on cold-adapted enzymes in comparison to their warm-adapted counterparts. Comparative sequence and structural studies allow the definition of a multitude of adaptation strategies. Different enzymes carried out diverse mechanisms to adapt to low temperatures, so that a general theory for enzyme cold adaptation cannot be formulated. However, some common features can be traced in dynamic and flexibility properties of these enzymes, as well as in their intra- and inter-molecular interaction networks. Interestingly, the current data suggest that a family-centered point of view is necessary in the comparative analyses of cold- and warm-adapted enzymes. In fact, enzymes belonging to the same family or superfamily, thus sharing at least the three-dimensional fold and common features of the functional sites, have evolved similar structural and dynamic patterns to overcome the detrimental effects of low temperatures.

Effect of Different Ceramic Crown Preparations on Tooth Structure Loss: An In Vitro Study

NASA Astrophysics Data System (ADS)

Ebrahimpour, Ashkan

Objective: To quantify and compare the amount of tooth-structure reduction following the full-coverage preparations for crown materials of porcelain-fused-to-metal, lithium disilicate glass-ceramic and yttria-stabilized tetragonal zirconia polycrystalline for three tooth morphologies. Methods: Groups of resin teeth of different morphologies were individually weighed to high precision, then prepared following the preparation guidelines. The teeth were re-weighed after preparation and the amount of structural reduction was calculated. Statistical analyses were performed to find out if there was a significant difference among the groups. Results: Amount of tooth reduction for zirconia crown preparations was the lowest and statistically different compared with the other two materials. No statistical significance was found between the amount of reduction for porcelain-fused-to-metal and lithium disilicate glass-ceramic crowns. Conclusion: Within the limitations of this study, more tooth structure can be saved when utilizing zirconia full-coverage restorations compared with lithium disilicate glass-ceramic and porcelain-fused-to-metal crowns in maxillary central incisors, first premolars and first molars.

Measuring the environmental effects of organic farming: A meta-analysis of structural variables in empirical research.

PubMed

Lee, Ki Song; Choe, Young Chan; Park, Sung Hee

2015-10-01

This study examined the structural variables affecting the environmental effects of organic farming compared to those of conventional farming. A meta-analysis based on 107 studies and 360 observations published from 1977 to 2012 compared energy efficiency (EE) and greenhouse gas emissions (GHGE) for organic and conventional farming. The meta-analysis systematically analyzed the results of earlier comparative studies and used logistic regression to identify the structural variables that contributed to differences in the effects of organic and conventional farming on the environment. The statistical evidence identified characteristics that differentiated the environmental effects of organic and conventional farming, which is controversial. The results indicated that data sources, sample size and product type significantly affected EE, whereas product type, cropping pattern and measurement unit significantly affected the GHGE of organic farming compared to conventional farming. Superior effects of organic farming on the environment were more likely to appear for larger samples, primary data rather than secondary data, monocropping rather than multicropping, and crops other than fruits and vegetables. The environmental effects of organic farming were not affected by the study period, geographic location, farm size, cropping pattern, or measurement method. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Changes in the structural and functional characteristics of fisher (Pekania pennanti) rest structures over time

Treesearch

Bill Zielinski; Fredrick V. Schlexer

2015-01-01

Resting habitat used by fishers (Pekania pennanti) has been relatively well studied but information on the persistence of their resting structures over time is unknown. We selected for reexamination 73 of 195 resting structures used by by fishers in northwestern California and compared their condition on the date they were found with their...

Learning and Memory Impairments in Patients with Minimal Hepatic Encephalopathy are Associated with Structural and Functional Connectivity Alterations in Hippocampus.

PubMed

García-García, Raquel; Cruz-Gómez, Álvaro Javier; Urios, Amparo; Mangas-Losada, Alba; Forn, Cristina; Escudero-García, Desamparados; Kosenko, Elena; Torregrosa, Isidro; Tosca, Joan; Giner-Durán, Remedios; Serra, Miguel Angel; Avila, César; Belloch, Vicente; Felipo, Vicente; Montoliu, Carmina

2018-06-25

Patients with minimal hepatic encephalopathy (MHE) show mild cognitive impairment associated with alterations in attentional and executive networks. There are no studies evaluating the relationship between memory in MHE and structural and functional connectivity (FC) changes in the hippocampal system. This study aimed to evaluate verbal learning and long-term memory in cirrhotic patients with (C-MHE) and without MHE (C-NMHE) and healthy controls. We assessed the relationship between alterations in memory and the structural integrity and FC of the hippocampal system. C-MHE patients showed impairments in learning, long-term memory, and recognition, compared to C-NMHE patients and controls. Cirrhotic patients showed reduced fimbria volume compared to controls. Larger volumes in hippocampus subfields were related to better memory performance in C-NMHE patients and controls. C-MHE patients presented lower FC between the L-presubiculum and L-precuneus than C-NMHE patients. Compared to controls, C-MHE patients had reduced FC between L-presubiculum and subiculum seeds and bilateral precuneus, which correlated with cognitive impairment and memory performance. Alterations in the FC of the hippocampal system could contribute to learning and long-term memory impairments in C-MHE patients. This study demonstrates the association between alterations in learning and long-term memory and structural and FC disturbances in hippocampal structures in cirrhotic patients.

Study of advanced composite structural design concepts for an arrow wing supersonic cruise configuration, task 3

NASA Technical Reports Server (NTRS)

1978-01-01

A structural design study was conducted to assess the relative merits of structural concepts using advanced composite materials for an advanced supersonic aircraft cruising at Mach 2.7. The configuration and structural arrangement developed during Task I and II of the study, was used as the baseline configuration. Allowable stresses and strains were established for boron and advanced graphite fibers based on projected fiber properties available in the next decade. Structural concepts were designed and analyzed using graphite polyimide and boron polyimide, applied to stiffened panels and conventional sandwich panels. The conventional sandwich panels were selected as the structural concept to be used on the wing structure. The upper and lower surface panels of the Task I arrow wing were redesigned using high-strength graphite polyimide sandwich panels over the titanium spars and ribs. The ATLAS computer system was used as the basis for stress analysis and resizing the surface panels using the loads from the Task II study, without adjustment for change in aeroelastic deformation. The flutter analysis indicated a decrease in the flutter speed compared to the baseline titanium wing design. The flutter analysis indicated a decrease in the flutter speed compared to the baseline titanium wing design. The flutter speed was increased to that of the titanium wing, with a weight penalty less than that of the metallic airplane.

Plant Defense Inhibitors Affect the Structures of Midgut Cells in Drosophila melanogaster and Callosobruchus maculatus

PubMed Central

Li-Byarlay, Hongmei; Pittendrigh, Barry R.; Murdock, Larry L.

2016-01-01

Plants produce proteins such as protease inhibitors and lectins as defenses against herbivorous insects and pathogens. However, no systematic studies have explored the structural responses in the midguts of insects when challenged with plant defensive proteins and lectins across different species. In this study, we fed two kinds of protease inhibitors and lectins to the fruit fly Drosophila melanogaster and alpha-amylase inhibitors and lectins to the cowpea bruchid Callosobruchus maculatus. We assessed the changes in midgut cell structures by comparing them with such structures in insects receiving normal diets or subjected to food deprivation. Using light and transmission electron microscopy in both species, we observed structural changes in the midgut peritrophic matrix as well as shortened microvilli on the surfaces of midgut epithelial cells in D. melanogaster. Dietary inhibitors and lectins caused similar lesions in the epithelial cells but not much change in the peritrophic matrix in both species. We also noted structural damages in the Drosophila midgut after six hours of starvation and changes were still present after 12 hours. Our study provided the first evidence of key structural changes of midguts using a comparative approach between a dipteran and a coleopteran. Our particular observation and discussion on plant–insect interaction and dietary stress are relevant for future mode of action studies of plant defensive protein in insect physiology. PMID:27594789

Plant Defense Inhibitors Affect the Structures of Midgut Cells in Drosophila melanogaster and Callosobruchus maculatus.

PubMed

Li-Byarlay, Hongmei; Pittendrigh, Barry R; Murdock, Larry L

2016-01-01

Plants produce proteins such as protease inhibitors and lectins as defenses against herbivorous insects and pathogens. However, no systematic studies have explored the structural responses in the midguts of insects when challenged with plant defensive proteins and lectins across different species. In this study, we fed two kinds of protease inhibitors and lectins to the fruit fly Drosophila melanogaster and alpha-amylase inhibitors and lectins to the cowpea bruchid Callosobruchus maculatus. We assessed the changes in midgut cell structures by comparing them with such structures in insects receiving normal diets or subjected to food deprivation. Using light and transmission electron microscopy in both species, we observed structural changes in the midgut peritrophic matrix as well as shortened microvilli on the surfaces of midgut epithelial cells in D. melanogaster. Dietary inhibitors and lectins caused similar lesions in the epithelial cells but not much change in the peritrophic matrix in both species. We also noted structural damages in the Drosophila midgut after six hours of starvation and changes were still present after 12 hours. Our study provided the first evidence of key structural changes of midguts using a comparative approach between a dipteran and a coleopteran. Our particular observation and discussion on plant-insect interaction and dietary stress are relevant for future mode of action studies of plant defensive protein in insect physiology.

Why are some plant-pollinator networks more nested than others?

PubMed

Song, Chuliang; Rohr, Rudolf P; Saavedra, Serguei

2017-10-01

Empirical studies have found that the mutualistic interactions forming the structure of plant-pollinator networks are typically more nested than expected by chance alone. Additionally, theoretical studies have shown a positive association between the nested structure of mutualistic networks and community persistence. Yet, it has been shown that some plant-pollinator networks may be more nested than others, raising the interesting question of which factors are responsible for such enhanced nested structure. It has been argued that ordered network structures may increase the persistence of ecological communities under less predictable environments. This suggests that nested structures of plant-pollinator networks could be more advantageous under highly seasonal environments. While several studies have investigated the link between nestedness and various environmental variables, unfortunately, there has been no unified answer to validate these predictions. Here, we move from the problem of describing network structures to the problem of comparing network structures. We develop comparative statistics, and apply them to investigate the association between the nested structure of 59 plant-pollinator networks and the temperature seasonality present in their locations. We demonstrate that higher levels of nestedness are associated with a higher temperature seasonality. We show that the previous lack of agreement came from an extended practice of using standardized measures of nestedness that cannot be compared across different networks. Importantly, our observations complement theory showing that more nested network structures can increase the range of environmental conditions compatible with species coexistence in mutualistic systems, also known as structural stability. This increase in nestedness should be more advantageous and occur more often in locations subject to random environmental perturbations, which could be driven by highly changing or seasonal environments. This synthesis of theory and observations could prove relevant for a better understanding of the ecological processes driving the assembly and persistence of ecological communities. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Exoskeletons of Bougainvilliidae and other Hydroidolina (Cnidaria, Hydrozoa): structure and composition

PubMed Central

Marian, José Eduardo A.R.; Migotto, Alvaro Esteves; Marques, Antonio Carlos

2017-01-01

The exoskeleton is an important source of characters for the taxonomy of Hydroidolina. It originates as epidermal secretions and, among other functions, protects the coenosarc of the polypoid stage. However, comparative studies on the exoskeletal tissue origin, development, chemical, and structural characteristics, as well as its evolution and homology, are few and fragmented. This study compares the structure and composition of the exoskeleton and underlying coenosarc in members of “Anthoathecata” and some Leptothecata, but does so mainly in bougainvilliid polyps histological analyses. We also studied the development of the exoskeleton under experimental conditions. We identified three types of glandular epidermal cells related to the origin of the exoskeleton and the secretion of its polysaccharides component. The exoskeleton of the species studied is either bilayered (perisarc and exosarc, especially in bougainvilliids) or corneous (perisarc). The exoskeleton varies in chemical composition, structural rigidity, thickness, extension, and coverage in the different regions of the colony. In bilayered exoskeletons, the exosarc is produced first and appears to be a key step in the formation of the rigid exoskeleton. The exoskeleton contains anchoring structures such as desmocytes and “perisarc extensions.” PMID:28224050

Effects of diabetes and hypertension on structure and distensibilty of human small coronary arteries.

PubMed

Lynch, Fiona M; Izzard, Ashley S; Austin, Clare; Prendergast, Brian; Keenan, Daniel; Malik, Rayaz A; Heagerty, Anthony M

2012-02-01

Previous studies have demonstrated that hypertension and diabetes induce significant structural remodelling of resistance arteries from various vascular beds. The hypothesis of this study is that structural alterations of small coronary arteries may occur during hypertension and diabetes. This study is the first to compare human coronary small resistance artery structure from normotensive and hypertensive patients, with and without diabetes undergoing coronary arterial bypass graft surgery. Small arteries were dissected from the atrial appendage removed from nondiabetic normotensive patients, nondiabetic hypertension and diabetic normotensive patients and hypertensive diabetic patients. Arteries were mounted in a pressure myograph and lumen diameter and wall thickness were measured across the pressure range of 3-100 mmHg to assess vessel structure and distensibility. There were no significant differences in the lumen diameter, wall thickness, wall-to-lumen ratio and cross-sectional area of arteries in all groups. Arteries from nondiabetic patients with hypertension demonstrated decreased distensibility compared with nondiabetic normotensive patients. There is no difference in distensibility between vessels from diabetic hypertensive patients and either diabetic or nondiabetic normotensive patients. Neither diabetes nor hypertension appears to have influenced arterial structure which may indicate that successful treatment of hypertension is associated with normal vascular structure in coronary small arteries.

Assembly of Space CFRP Structures with Racing Sailing Boats Technology

NASA Astrophysics Data System (ADS)

Nieto, Jose; Yuste, Laura; Pipo, Alvaro; Santarsiero, Pablo; Bureo, Rafael

2014-06-01

Carbon Fiber Reinforced Plastic (CFRP) is commonly used in space applications to get structures with good mechanical performances and a reduced mass. Most of larger parts of spatial structures are already made of CFRP but the achieved weight saving may be jeopardized by the use of metallic brackets as joining elements. This paper describes the work carried out to study and evaluate ways of reducing weight and costs of the joints between structural elements commonly used in space applications.The main objective of this project is to adapt design solutions coming from the racing sailing boats technology to space applications: the use of out-of autoclave (OoA) cured CFRP joints. In addition to that other CFRP solution common in space business, 3D- RTM Bracket, has been evaluated.This development studies the manufacturing and assembly feasibility making use of these CFRP technologies.This study also compares traditional metallic solutions with innovative CFRP ones in terms of mechanical performances at elementary level. Weight and cost of presented solutions are also compared.

Thermal-structural modeling of polymer Bragg grating waveguides illuminated by a light emitting diode.

PubMed

Joon Kim, Kyoung; Bar-Cohen, Avram; Han, Bongtae

2012-02-20

This study reports both analytical and numerical thermal-structural models of polymer Bragg grating (PBG) waveguides illuminated by a light emitting diode (LED). A polymethyl methacrylate (PMMA) Bragg grating (BG) waveguide is chosen as an analysis vehicle to explore parametric effects of incident optical powers and substrate materials on the thermal-structural behavior of the BG. Analytical models are verified by comparing analytically predicted average excess temperatures, and thermally induced axial strains and stresses with numerical predictions. A parametric study demonstrates that the PMMA substrate induces more adverse effects, such as higher excess temperatures, complex axial temperature profiles, and greater and more complicated thermally induced strains in the BG compared with the Si substrate. © 2012 Optical Society of America

[A structural protein study of the influenza A (H1N1) virus by polyacrylamide gel electrophoresis].

PubMed

Pérez Guevara, M T; Savón Valdés, C; Rivas Arjona, M; Goyenechea Hernández, A

1992-01-01

Influenza is an acute respiratory disease typically appearing as an epidemic. Three immunological types of the influenza virus are known: A, B and C. Continually, antigen changes occur, especially in type A. Therefore, a comparative study was carried out on 4 influenza A(H1N1) virus strains in relation to protein structure (surface antigens), by using polyacrylamide gel electrophoresis by the modified Laemmli method. The objective was to compare the structural proteins of the A/Havana/1292/78 (H1N1) national strain with the proteins of 3 international pattern strains. In all the cases, 6 bands were detected by densitometry. In the 4 strains studied the most abundant protein was M. Great differences between the Cuban strain and the 3 international patterns were not seen.

Precision and accuracy in smFRET based structural studies—A benchmark study of the Fast-Nano-Positioning System

NASA Astrophysics Data System (ADS)

Nagy, Julia; Eilert, Tobias; Michaelis, Jens

2018-03-01

Modern hybrid structural analysis methods have opened new possibilities to analyze and resolve flexible protein complexes where conventional crystallographic methods have reached their limits. Here, the Fast-Nano-Positioning System (Fast-NPS), a Bayesian parameter estimation-based analysis method and software, is an interesting method since it allows for the localization of unknown fluorescent dye molecules attached to macromolecular complexes based on single-molecule Förster resonance energy transfer (smFRET) measurements. However, the precision, accuracy, and reliability of structural models derived from results based on such complex calculation schemes are oftentimes difficult to evaluate. Therefore, we present two proof-of-principle benchmark studies where we use smFRET data to localize supposedly unknown positions on a DNA as well as on a protein-nucleic acid complex. Since we use complexes where structural information is available, we can compare Fast-NPS localization to the existing structural data. In particular, we compare different dye models and discuss how both accuracy and precision can be optimized.

Numerical analysis of light extraction enhancement of GaN-based thin-film flip-chip light-emitting diodes with high-refractive-index buckling nanostructures

NASA Astrophysics Data System (ADS)

Yue, Qing-Yang; Yang, Yang; Cheng, Zhen-Jia; Guo, Cheng-Shan

2018-06-01

In this work, the light extraction efficiency enhancement of GaN-based thin-film flip-chip (TFFC) light-emitting diodes (LEDs) with high-refractive-index (TiO2) buckling nanostructures was studied using the three-dimensional finite difference time domain method. Compared with 2-D photonic crystals, the buckling structures have the advantages of a random directionality and a broad distribution in periodicity, which can effectively extract the guided light propagating in all azimuthal directions over a wide spectrum. Numerical studies revealed that the light extraction efficiency of buckling-structured LEDs reaches 1.1 times that of triangular lattice photonic crystals. The effects of the buckling structure feature sizes and the thickness of the N-GaN layer on the light extraction efficiency for TFFC LEDs were also investigated systematically. With optimized structural parameters, a significant light extraction enhancement of about 2.6 times was achieved for TiO2 buckling-structured TFFC LEDs compared with planar LEDs.

Self-assessment differences between genders in a low-stakes objective structured clinical examination (OSCE).

PubMed

Madrazo, Lorenzo; Lee, Claire B; McConnell, Meghan; Khamisa, Karima

2018-06-15

Physicians and medical students are generally poor-self assessors. Research suggests that this inaccuracy in self-assessment differs by gender among medical students whereby females underestimate their performance compared to their male counterparts. However, whether this gender difference in self-assessment is observable in low-stakes scenarios remains unclear. Our study's objective was to determine whether self-assessment differed between male and female medical students when compared to peer-assessment in a low-stakes objective structured clinical examination. Thirty-three (15 males, 18 females) third-year students participated in a 5-station mock objective structured clinical examination. Trained fourth-year student examiners scored their performance on a 6-point Likert-type global rating scale. Examinees also scored themselves using the same scale. To examine gender differences in medical students' self-assessment abilities, mean self-assessment global rating scores were compared with peer-assessment global rating scores using an independent samples t test. Overall, female students' self-assessment scores were significantly lower compared to peer-assessment (p < 0.001), whereas no significant difference was found between self- and peer-assessment scores for male examinees (p = 0.228). This study provides further evidence that underestimation in self-assessment among females is observable even in a low-stakes formative objective structured clinical examination facilitated by fellow medical students.

A scanning electron microscopy study of the macro-crystalline structure of 2-(2,4-dinitrobenzyl) pyridine

NASA Technical Reports Server (NTRS)

Ware, Jacqueline; Hammond, Ernest C., Jr.

1989-01-01

The compound, 2-(2,4-dinitrobenzyl) pyridine, was synthesized in the laboratory; an introductory level electron microscopy study of the macro-crystalline structure was conducted using the scanning electron microscope (SEM). The structure of these crystals was compared with the macrostructure of the crystal of 2-(2,4-dinitrobenzyl) pyridinium bromide, the hydrobromic salt of the compound which was also synthesized in the laboratory. A scanning electron microscopy crystal study was combined with a study of the principle of the electron microscope.

In silico studies on tryparedoxin peroxidase of Leishmania infantum: structural aspects.

PubMed

Singh, Bishal Kumar; Dubey, Vikash Kumar

2009-09-01

Tryparedoxin peroxidase (TryP) is a key enzyme of the trypanothione-dependent metabolism for removal of oxidative stress in leishmania. These enzymes function as antioxidants through their peroxidase and peroxynitrite reductase activities. Inhibitors of this enzyme are presumed to be antilesihmania drugs and structural studies are prerequisite of rational drug design. We have constructed three dimensional structure of TryP of Leishmania infantum using comparative modeling. Structural analysis reveals several interesting features. Moreover, it shows remarkable structural difference with human host glutathione peroxidase, an enzyme involved in similar function and TryP from Leishmania major.

Comparative Study on the Senior Secondary School Mathematics Curricula Development in Ethiopia and Australia

ERIC Educational Resources Information Center

Meleta, Fufa E.; Zhang, Weizhong

2017-01-01

The main objective of this study is to compare the process of the senior secondary school mathematics curricula development in Ethiopia and Australia. The study was investigated qualitatively with document analysis and semi-structured interview research methods. The documents were collected from Federal Democratic Republic of Ethiopia Ministry of…

Brain structure and executive functions in children with cerebral palsy: a systematic review.

PubMed

Weierink, Lonneke; Vermeulen, R Jeroen; Boyd, Roslyn N

2013-05-01

This systematic review aimed to establish the current knowledge about brain structure and executive function (EF) in children with cerebral palsy (CP). Five databases were searched (up till July 2012). Six articles met the inclusion criteria, all included structural brain imaging though no functional brain imaging. Study quality was assessed using the STROBE checklist. All articles scored between 58.7% and 70.5% for quality (100% is the maximum score). The included studies all reported poorer performance on EF tasks for children with CP compared to children without CP. For the selected EF measures non-significant effect sizes were found for the CP group compared to a semi-control group (children without cognitive deficits but not included in a control group). This could be due to the small sample sizes, group heterogeneity and lack of comparison of the CP group to typically developing children. The included studies did not consider specific brain areas associated with EF performance. To conclude, there is a paucity of brain imaging studies focused on EF in children with CP, especially of studies that include functional brain imaging. Outcomes of the present studies are difficult to compare as each study included different EF measures and cortical abnormality measures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Does Family Structure Matter? Comparing the Life Goals and Aspirations of Learners in Secondary Schools

ERIC Educational Resources Information Center

Davids, Eugene Lee; Roman, Nicolette Vanessa

2013-01-01

The aim of this study was to compare the goals and aspirations of learners from single- and two-parent families. The study used a quantitative methodology with a cross-sectional comparative group design. The sample consisted of 853 Grade 11 learners from secondary schools in the Northern, Southern and Metro Central education districts in the…

Does Compare-Contrast Text Structure Help Students with Autism Spectrum Disorder Comprehend Science Text?

ERIC Educational Resources Information Center

Carnahan, Christina R.; Williamson, Pamela S.

2013-01-01

Using a single-subject reversal design, this study evaluated the use of a compare-contrast strategy on the ability of students with autism spectrum disorder to comprehend science text. Three middle school students with high-functioning autism and their teacher participated in this study. A content analysis comparing the number of meaning units in…

Varieties of Organizational Conflict

ERIC Educational Resources Information Center

Pondy, Louis R.

1969-01-01

The viewpoints and findings of the seven empirical studies of organizational conflict contained in this issue are compared and contrasted. A distinction is made between conflict within a stable organization structure and conflict aimed at changing the organization structure. (Author)

Comparison of Knowledge Structures with the Pathfinder Scaling Algorithm.

ERIC Educational Resources Information Center

McGaghie, William C.

The cognitive structure of 13 concepts in pulmonary physiology was explored among 112 first-year medical students and among 32 faculty members in three different expertise groups in a knowledge representation study. Purposes were to assess the degree of agreement among faculty members, map students' concept structures, and compare the similarity…

The study of features of the structural organization of the au-tomated information processing system of the collective type

NASA Astrophysics Data System (ADS)

Nikolaev, V. N.; Titov, D. V.; Syryamkin, V. I.

2018-05-01

The comparative assessment of the level of channel capacity of different variants of the structural organization of the automated information processing systems is made. The information processing time assessment model depending on the type of standard elements and their structural organization is developed.

The Formulation of Argument Structure in SLI: An Eye-Movement Study

ERIC Educational Resources Information Center

Andreu, Llorenc; Sanz-Torrent, Monica; Olmos, Joan Guardia; MacWhinney, Brian

2013-01-01

This study investigated the formulation of verb argument structure in Catalan- and Spanish-speaking children with specific language impairment (SLI) and typically developing age-matched controls. We compared how language production can be guided by conceptual factors, such as the organization of the entities participating in an event and knowledge…

Example-Based Learning: Exploring the Use of Matrices and Problem Variability

ERIC Educational Resources Information Center

Hancock-Niemic, Mary A.; Lin, Lijia; Atkinson, Robert K.; Renkl, Alexander; Wittwer, Joerg

2016-01-01

The purpose of the study was to investigate the efficacy of using faded worked examples presented in matrices with problem structure variability to enhance learners' ability to recognize the underlying structure of the problems. Specifically, this study compared the effects of matrix-format versus linear-format faded worked examples combined with…

A Comparative Study of the Effects of Two Teaching Strategies in an Activity-Centered Science Program on Middle School Students' Need-Affiliation and Teacher Dependency Behaviors.

ERIC Educational Resources Information Center

Vinelli, Jose L.; And Others

1979-01-01

Studies the effects of student-structured (SSLS) and teacher-structured (TSLS) teaching strategies. SSLS students consistently exhibited lower frequencies of teacher dependency behaviors than TSLS students. Need affiliation results varied with the grade level of students. (MA)

Advancing Scientific Reasoning in Upper Elementary Classrooms: Direct Instruction versus Task Structuring

ERIC Educational Resources Information Center

Lazonder, Ard W.; Wiskerke-Drost, Sjanou

2015-01-01

Several studies found that direct instruction and task structuring can effectively promote children's ability to design unconfounded experiments. The present study examined whether the impact of these interventions extends to other scientific reasoning skills by comparing the inquiry activities of 55 fifth-graders randomly assigned to one of…

The Wh-Adverbial & Which-NP Construction Asymmetry within Island Structures in Turkish

ERIC Educational Resources Information Center

Çakir, Sinan

2017-01-01

The present study is a follow-up study of Çakir (2016b) which focused on the wh-adverbial & which NP constructions asymmetry within island structures in Turkish. The characteristics of wh-adverbial nasil "how" is compared with the which-NP constructions "hangisekilde" "in what way" and "hangihalde"…

Comparative study of some commercial samples of naga bhasma.

PubMed

Wadekar, Mrudula; Gogte, Viswas; Khandagale, Prasad; Prabhune, Asmita

2004-04-01

Naga bhasma is one of those reputed ayurvedic bhasmas which are claimed to possess some extraordinary medical properties. However, identification of a genuine sample of naga bhasma is a challenging problem. Because at present naga bhasma is manufactured by different ayurvedic pharmacies, by following different methods, these products are not standardised either from chemical and structural point of view. Therefore, comparative study of these samples using modern analytical techniques is important and necessary to understand their current status. In this communication, such study of naga bhasma from chemical and structural point of view is reported by using XRD, IR and UV spectroscopy and thermogravimetry.

Abnormalities in Structural Covariance of Cortical Gyrification in Parkinson's Disease.

PubMed

Xu, Jinping; Zhang, Jiuquan; Zhang, Jinlei; Wang, Yue; Zhang, Yanling; Wang, Jian; Li, Guanglin; Hu, Qingmao; Zhang, Yuanchao

2017-01-01

Although abnormal cortical morphology and connectivity between brain regions (structural covariance) have been reported in Parkinson's disease (PD), the topological organizations of large-scale structural brain networks are still poorly understood. In this study, we investigated large-scale structural brain networks in a sample of 37 PD patients and 34 healthy controls (HC) by assessing the structural covariance of cortical gyrification with local gyrification index (lGI). We demonstrated prominent small-world properties of the structural brain networks for both groups. Compared with the HC group, PD patients showed significantly increased integrated characteristic path length and integrated clustering coefficient, as well as decreased integrated global efficiency in structural brain networks. Distinct distributions of hub regions were identified between the two groups, showing more hub regions in the frontal cortex in PD patients. Moreover, the modular analyses revealed significantly decreased integrated regional efficiency in lateral Fronto-Insula-Temporal module, and increased integrated regional efficiency in Parieto-Temporal module in the PD group as compared to the HC group. In summary, our study demonstrated altered topological properties of structural networks at a global, regional and modular level in PD patients. These findings suggests that the structural networks of PD patients have a suboptimal topological organization, resulting in less effective integration of information between brain regions.

Empirically evaluating decision-analytic models.

PubMed

Goldhaber-Fiebert, Jeremy D; Stout, Natasha K; Goldie, Sue J

2010-08-01

Model-based cost-effectiveness analyses support decision-making. To augment model credibility, evaluation via comparison to independent, empirical studies is recommended. We developed a structured reporting format for model evaluation and conducted a structured literature review to characterize current model evaluation recommendations and practices. As an illustration, we applied the reporting format to evaluate a microsimulation of human papillomavirus and cervical cancer. The model's outputs and uncertainty ranges were compared with multiple outcomes from a study of long-term progression from high-grade precancer (cervical intraepithelial neoplasia [CIN]) to cancer. Outcomes included 5 to 30-year cumulative cancer risk among women with and without appropriate CIN treatment. Consistency was measured by model ranges overlapping study confidence intervals. The structured reporting format included: matching baseline characteristics and follow-up, reporting model and study uncertainty, and stating metrics of consistency for model and study results. Structured searches yielded 2963 articles with 67 meeting inclusion criteria and found variation in how current model evaluations are reported. Evaluation of the cervical cancer microsimulation, reported using the proposed format, showed a modeled cumulative risk of invasive cancer for inadequately treated women of 39.6% (30.9-49.7) at 30 years, compared with the study: 37.5% (28.4-48.3). For appropriately treated women, modeled risks were 1.0% (0.7-1.3) at 30 years, study: 1.5% (0.4-3.3). To support external and projective validity, cost-effectiveness models should be iteratively evaluated as new studies become available, with reporting standardized to facilitate assessment. Such evaluations are particularly relevant for models used to conduct comparative effectiveness analyses.

The Effects of Different Training Structures in the Establishment of Conditional Discriminations and Subsequent Performance on Tests for Stimulus Equivalence

ERIC Educational Resources Information Center

Arntzen, Erik; Grondahl, Terje; Eilifsen, Christoffer

2010-01-01

Previous studies comparing groups of subjects have indicated differential probabilities of stimulus equivalence outcome as a function of training structures. One-to-Many (OTM) and Many-to-One (MTO) training structures seem to produce positive outcomes on tests for stimulus equivalence more often than a Linear Series (LS) training structure does.…

New Era of Studying RNA Secondary Structure and Its Influence on Gene Regulation in Plants.

PubMed

Yang, Xiaofei; Yang, Minglei; Deng, Hongjing; Ding, Yiliang

2018-01-01

The dynamic structure of RNA plays a central role in post-transcriptional regulation of gene expression such as RNA maturation, degradation, and translation. With the rise of next-generation sequencing, the study of RNA structure has been transformed from in vitro low-throughput RNA structure probing methods to in vivo high-throughput RNA structure profiling. The development of these methods enables incremental studies on the function of RNA structure to be performed, revealing new insights of novel regulatory mechanisms of RNA structure in plants. Genome-wide scale RNA structure profiling allows us to investigate general RNA structural features over 10s of 1000s of mRNAs and to compare RNA structuromes between plant species. Here, we provide a comprehensive and up-to-date overview of: (i) RNA structure probing methods; (ii) the biological functions of RNA structure; (iii) genome-wide RNA structural features corresponding to their regulatory mechanisms; and (iv) RNA structurome evolution in plants.

Chromosomal structures and repetitive sequences divergence in Cucumis species revealed by comparative cytogenetic mapping.

PubMed

Zhang, Yunxia; Cheng, Chunyan; Li, Ji; Yang, Shuqiong; Wang, Yunzhu; Li, Ziang; Chen, Jinfeng; Lou, Qunfeng

2015-09-25

Differentiation and copy number of repetitive sequences affect directly chromosome structure which contributes to reproductive isolation and speciation. Comparative cytogenetic mapping has been verified an efficient tool to elucidate the differentiation and distribution of repetitive sequences in genome. In present study, the distinct chromosomal structures of five Cucumis species were revealed through genomic in situ hybridization (GISH) technique and comparative cytogenetic mapping of major satellite repeats. Chromosome structures of five Cucumis species were investigated using GISH and comparative mapping of specific satellites. Southern hybridization was employed to study the proliferation of satellites, whose structural characteristics were helpful for analyzing chromosome evolution. Preferential distribution of repetitive DNAs at the subtelomeric regions was found in C. sativus, C hystrix and C. metuliferus, while majority was positioned at the pericentromeric heterochromatin regions in C. melo and C. anguria. Further, comparative GISH (cGISH) through using genomic DNA of other species as probes revealed high homology of repeats between C. sativus and C. hystrix. Specific satellites including 45S rDNA, Type I/II, Type III, Type IV, CentM and telomeric repeat were then comparatively mapped in these species. Type I/II and Type IV produced bright signals at the subtelomeric regions of C. sativus and C. hystrix simultaneously, which might explain the significance of their amplification in the divergence of Cucumis subgenus from the ancient ancestor. Unique positioning of Type III and CentM only at the centromeric domains of C. sativus and C. melo, respectively, combining with unique southern bands, revealed rapid evolutionary patterns of centromeric DNA in Cucumis. Obvious interstitial telomeric repeats were observed in chromosomes 1 and 2 of C. sativus, which might provide evidence of the fusion hypothesis of chromosome evolution from x = 12 to x = 7 in Cucumis species. Besides, the significant correlation was found between gene density along chromosome and GISH band intensity in C. sativus and C. melo. In summary, comparative cytogenetic mapping of major satellites and GISH revealed the distinct differentiation of chromosome structure during species formation. The evolution of repetitive sequences was the main force for the divergence of Cucumis species from common ancestor.

Structural imaging of the brain reveals decreased total brain and total gray matter volumes in obese but not in lean women with polycystic ovary syndrome compared to body mass index-matched counterparts.

PubMed

Ozgen Saydam, Basak; Has, Arzu Ceylan; Bozdag, Gurkan; Oguz, Kader Karli; Yildiz, Bulent Okan

2017-07-01

To detect differences in global brain volumes and identify relations between brain volume and appetite-related hormones in women with polycystic ovary syndrome (PCOS) compared to body mass index-matched controls. Forty subjects participated in this study. Cranial magnetic resonance imaging and measurements of fasting ghrelin, leptin and glucagon-like peptide 1 (GLP-1), as well as GLP-1 levels during mixed-meal tolerance test (MTT), were performed. Total brain volume and total gray matter volume (GMV) were decreased in obese PCOS compared to obese controls (p < 0.05 for both) whereas lean PCOS and controls did not show a significant difference. Secondary analyses of regional brain volumes showed decreases in GMV of the caudate nucleus, ventral diencephalon and hippocampus in obese PCOS compared to obese controls (p < 0.05 for all), whereas lean patients with PCOS had lower GMV in the amygdala than lean controls (p < 0.05). No significant relations were detected between structural differences and measured hormone levels at baseline or during MTT. This study, investigating structural brain alterations in PCOS, suggests volumetric reductions in global brain areas in obese women with PCOS. Functional studies with larger sample size are needed to determine physiopathological roles of these changes and potential effects of long-term medical management on brain structure of PCOS.

Evaluation of Ultrasonic Fiber Structure Extraction Technique Using Autopsy Specimens of Liver

NASA Astrophysics Data System (ADS)

Yamaguchi, Tadashi; Hirai, Kazuki; Yamada, Hiroyuki; Ebara, Masaaki; Hachiya, Hiroyuki

2005-06-01

It is very important to diagnose liver cirrhosis noninvasively and correctly. In our previous studies, we proposed a processing technique to detect changes in liver tissue in vivo. In this paper, we propose the evaluation of the relationship between liver disease and echo information using autopsy specimens of a human liver in vitro. It is possible to verify the function of a processing parameter clearly and to compare the processing result and the actual human liver tissue structure by in vitro experiment. In the results of our processing technique, information that did not obey a Rayleigh distribution from the echo signal of the autopsy liver specimens was extracted depending on changes in a particular processing parameter. The fiber tissue structure of the same specimen was extracted from a number of histological images of stained tissue. We constructed 3D structures using the information extracted from the echo signal and the fiber structure of the stained tissue and compared the two. By comparing the 3D structures, it is possible to evaluate the relationship between the information that does not obey a Rayleigh distribution of the echo signal and the fibrosis structure.

Comparative genomics of Eucalyptus and Corymbia reveals low rates of genome structural rearrangement.

PubMed

Butler, J B; Vaillancourt, R E; Potts, B M; Lee, D J; King, G J; Baten, A; Shepherd, M; Freeman, J S

2017-05-22

Previous studies suggest genome structure is largely conserved between Eucalyptus species. However, it is unknown if this conservation extends to more divergent eucalypt taxa. We performed comparative genomics between the eucalypt genera Eucalyptus and Corymbia. Our results will facilitate transfer of genomic information between these important taxa and provide further insights into the rate of structural change in tree genomes. We constructed three high density linkage maps for two Corymbia species (Corymbia citriodora subsp. variegata and Corymbia torelliana) which were used to compare genome structure between both species and Eucalyptus grandis. Genome structure was highly conserved between the Corymbia species. However, the comparison of Corymbia and E. grandis suggests large (from 1-13 MB) intra-chromosomal rearrangements have occurred on seven of the 11 chromosomes. Most rearrangements were supported through comparisons of the three independent Corymbia maps to the E. grandis genome sequence, and to other independently constructed Eucalyptus linkage maps. These are the first large scale chromosomal rearrangements discovered between eucalypts. Nonetheless, in the general context of plants, the genomic structure of the two genera was remarkably conserved; adding to a growing body of evidence that conservation of genome structure is common amongst woody angiosperms.

PIV study of flow through porous structure using refractive index matching

NASA Astrophysics Data System (ADS)

Häfeli, Richard; Altheimer, Marco; Butscher, Denis; Rudolf von Rohr, Philipp

2014-05-01

An aqueous solution of sodium iodide and zinc iodide is proposed as a fluid that matches the refractive index of a solid manufactured by rapid prototyping. This enabled optical measurements in single-phase flow through porous structures. Experiments were also done with an organic index-matching fluid (anisole) in porous structures of different dimensions. To compare experiments with different viscosities and dimensions, we employed Reynolds similarity to deduce the scaling laws. One of the target quantities of our investigation was the dissipation rate of turbulent kinetic energy. Different models for the dissipation rate estimation were evaluated by comparing isotropy ratios. As in many other studies also, our experiments were not capable of resolving the velocity field down to the Kolmogorov length scale, and therefore, the dissipation rate has to be considered as underestimated. This is visible in experiments of different relative resolutions. However, being near the Kolmogorov scale allows estimating a reproducible, yet underestimated spatial distribution of dissipation rate inside the porous structure. Based on these results, the model was used to estimate the turbulent diffusivity. Comparing it to the dispersion coefficient obtained in the same porous structure, we conclude that even at the turbulent diffusivity makes up only a small part of mass transfer in axial direction. The main part is therefore attributed to Taylor dispersion.

Electronic structure and insulating gap in epitaxial VO 2 polymorphs

DOE PAGES

Lee, Shinbuhm; Meyer, Tricia L.; Sohn, Changhee; ...

2015-12-24

Here, determining the origin of the insulating gap in the monoclinic VO 2(M1) is a long-standing issue. The difficulty of this study arises from the simultaneous occurrence of structural and electronic transitions upon thermal cycling. Here, we compare the electronic structure of the M1 phase with that of single crystalline insulating VO 2(A) and VO 2(B) thin films to better understand the insulating phase of VO 2. As these A and B phases do not undergo a structural transition upon thermal cycling, we comparatively study the origin of the gap opening in the insulating VO 2 phases. By x-ray absorptionmore » and optical spectroscopy, we find that the shift of unoccupied t 2g orbitals away from the Fermi level is a common feature, which plays an important role for the insulating behavior in VO 2 polymorphs. The distinct splitting of the half-filled t 2g orbital is observed only in the M1 phase, widening the bandgap up to ~0.6 eV. Our approach of comparing all three insulating VO 2 phases provides insight into a better understanding of the electronic structure and the origin of the insulating gap in VO 2.« less

Lessons from an evolving rRNA: 16S and 23S rRNA structures from a comparative perspective

NASA Technical Reports Server (NTRS)

Gutell, R. R.; Larsen, N.; Woese, C. R.

1994-01-01

The 16S and 23S rRNA higher-order structures inferred from comparative analysis are now quite refined. The models presented here differ from their immediate predecessors only in minor detail. Thus, it is safe to assert that all of the standard secondary-structure elements in (prokaryotic) rRNAs have been identified, with approximately 90% of the individual base pairs in each molecule having independent comparative support, and that at least some of the tertiary interactions have been revealed. It is interesting to compare the rRNAs in this respect with tRNA, whose higher-order structure is known in detail from its crystal structure (36) (Table 2). It can be seen that rRNAs have as great a fraction of their sequence in established secondary-structure elements as does tRNA. However, the fact that the former show a much lower fraction of identified tertiary interactions and a greater fraction of unpaired nucleotides than the latter implies that many of the rRNA tertiary interactions remain to be located. (Alternatively, the ribosome might involve protein-rRNA rather than intramolecular rRNA interactions to stabilize three-dimensional structure.) Experimental studies on rRNA are consistent to a first approximation with the structures proposed here, confirming the basic assumption of comparative analysis, i.e., that bases whose compositions strictly covary are physically interacting. In the exhaustive study of Moazed et al. (45) on protection of the bases in the small-subunit rRNA against chemical modification, the vast majority of bases inferred to pair by covariation are found to be protected from chemical modification, both in isolated small-subunit rRNA and in the 30S subunit. The majority of the tertiary interactions are reflected in the chemical protection data as well (45). On the other hand, many of the bases not shown as paired in Fig. 1 are accessible to chemical attack (45). However, in this case a sizeable fraction of them are also protected against chemical modification (in the isolated rRNA), which suggests that considerable higher-order structure remains to be found (although all of it may not involve base-base interactions and so may not be detectable by comparative analysis). The agreement between the higher-order structure of the small-subunit rRNA and protection against chemical modification is not perfect, however; some bases shown to covary canonically are accessible to chemical modification (45).(ABSTRACT TRUNCATED AT 400 WORDS).

Comparative evaluation of Populus variants total sugar release and structural features following pretreatment and digestion by two distinct biological systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, Vanessa A.; Kothari, Ninad; Bhagia, Samarthya

Populus natural variants have been shown to realize a broad range of sugar yields during saccharification, however, the structural features responsible for higher sugar release from natural variants are not clear. In addition, the sugar release patterns resulting from digestion with two distinct biological systems, fungal enzymes and Clostridium thermocellum, have yet to be evaluated and compared. This study evaluates the effect of structural features of three natural variant Populus lines, which includes the line BESC standard, with respect to the overall process of sugar release for two different biological systems.

Comparative evaluation of Populus variants total sugar release and structural features following pretreatment and digestion by two distinct biological systems

DOE PAGES

Thomas, Vanessa A.; Kothari, Ninad; Bhagia, Samarthya; ...

2017-11-30

Populus natural variants have been shown to realize a broad range of sugar yields during saccharification, however, the structural features responsible for higher sugar release from natural variants are not clear. In addition, the sugar release patterns resulting from digestion with two distinct biological systems, fungal enzymes and Clostridium thermocellum, have yet to be evaluated and compared. This study evaluates the effect of structural features of three natural variant Populus lines, which includes the line BESC standard, with respect to the overall process of sugar release for two different biological systems.

Application of Tryptophan Fluorescence Bandwidth-Maximum Plot in Analysis of Monoclonal Antibody Structure.

PubMed

Huang, Cheng-Yen; Hsieh, Ming-Ching; Zhou, Qinwei

2017-04-01

Monoclonal antibodies have become the fastest growing protein therapeutics in recent years. The stability and heterogeneity pertaining to its physical and chemical structures remain a big challenge. Tryptophan fluorescence has been proven to be a versatile tool to monitor protein tertiary structure. By modeling the tryptophan fluorescence emission envelope with log-normal distribution curves, the quantitative measure can be exercised for the routine characterization of monoclonal antibody overall tertiary structure. Furthermore, the log-normal deconvolution results can be presented as a two-dimensional plot with tryptophan emission bandwidth vs. emission maximum to enhance the resolution when comparing samples or as a function of applied perturbations. We demonstrate this by studying four different monoclonal antibodies, which show the distinction on emission bandwidth-maximum plot despite their similarity in overall amino acid sequences and tertiary structures. This strategy is also used to demonstrate the tertiary structure comparability between different lots manufactured for one of the monoclonal antibodies (mAb2). In addition, in the unfolding transition studies of mAb2 as a function of guanidine hydrochloride concentration, the evolution of the tertiary structure can be clearly traced in the emission bandwidth-maximum plot.

Bond-slip detection of concrete-encased composite structure using electro-mechanical impedance technique

NASA Astrophysics Data System (ADS)

Liang, Yabin; Li, Dongsheng; Parvasi, Seyed Mohammad; Kong, Qingzhao; Lim, Ing; Song, Gangbing

2016-09-01

Concrete-encased composite structure is a type of structure that takes the advantages of both steel and concrete materials, showing improved strength, ductility, and fire resistance compared to traditional reinforced concrete structures. The interface between concrete and steel profiles governs the interaction between these two materials under loading, however, debonding damage between these two materials may lead to severe degradation of the load transferring capacity which will affect the structural performance significantly. In this paper, the electro-mechanical impedance (EMI) technique using piezoceramic transducers was experimentally investigated to detect the bond-slip occurrence of the concrete-encased composite structure. The root-mean-square deviation is used to quantify the variations of the impedance signatures due to the presence of the bond-slip damage. In order to verify the validity of the proposed method, finite element model analysis was performed to simulate the behavior of concrete-steel debonding based on a 3D finite element concrete-steel bond model. The computed impedance signatures from the numerical results are compared with the results obtained from the experimental study, and both the numerical and experimental studies verify the proposed EMI method to detect bond slip of a concrete-encased composite structure.

Optimization of controllability and robustness of complex networks by edge directionality

NASA Astrophysics Data System (ADS)

Liang, Man; Jin, Suoqin; Wang, Dingjie; Zou, Xiufen

2016-09-01

Recently, controllability of complex networks has attracted enormous attention in various fields of science and engineering. How to optimize structural controllability has also become a significant issue. Previous studies have shown that an appropriate directional assignment can improve structural controllability; however, the evolution of the structural controllability of complex networks under attacks and cascading has always been ignored. To address this problem, this study proposes a new edge orientation method (NEOM) based on residual degree that changes the link direction while conserving topology and directionality. By comparing the results with those of previous methods in two random graph models and several realistic networks, our proposed approach is demonstrated to be an effective and competitive method for improving the structural controllability of complex networks. Moreover, numerical simulations show that our method is near-optimal in optimizing structural controllability. Strikingly, compared to the original network, our method maintains the structural controllability of the network under attacks and cascading, indicating that the NEOM can also enhance the robustness of controllability of networks. These results alter the view of the nature of controllability in complex networks, change the understanding of structural controllability and affect the design of network models to control such networks.

Cognitive and brain structural changes in a lung cancer population.

PubMed

Simó, Marta; Root, James C; Vaquero, Lucía; Ripollés, Pablo; Jové, Josep; Ahles, Tim; Navarro, Arturo; Cardenal, Felipe; Bruna, Jordi; Rodríguez-Fornells, Antoni

2015-01-01

No study has examined structural brain changes specifically associated with chemotherapy in a lung cancer population. The aim of this cross-sectional study was to assess differences in brain structure between small-cell lung cancer patients (C+) following chemotherapy, non-small-cell lung cancer patients (C-) before chemotherapy and healthy controls (HC). Twenty-eight small-cell lung cancer patients underwent a neuropsychological assessment and a structural magnetic resonance imaging, including T1-weighted and diffusion tensor imaging to examine gray matter density and white matter (WM) integrity, respectively, 1 month following completion of platinum-based chemotherapy. This group was compared with 20 age and education-matched non-small-cell lung cancer patients before receiving chemotherapy and 20 HC. Both C+ and C- groups exhibited cognitive impairment compared with the HC group. The C+ group performed significantly worse than HC in verbal fluency and visuospatial subtests; C- performed significantly worse than both C+ and HC in verbal memory. Voxel-based morphometry analysis revealed lower gray matter density in the insula and parahippocampal gyrus bilaterally, and left anterior cingulate cortex in C+ compared with HC. Diffusion tensor imaging indices showed focal decreased WM integrity in left cingulum and bilateral inferior longitudinal fasciculus in the C+ group and more widespread decreased integrity in the C- group compared with the HC group. This study demonstrates that lung cancer patients exhibit cognitive impairment before and after chemotherapy. Before the treatment, C- showed verbal memory deficits as well as a widespread WM damage. Following treatment, the C+ group performed exhibited lower visuospatial and verbal fluency abilities, together with structural gray matter and WM differences in bilateral regions integrating the paralimbic system.

A Comparison of Structurally Connected and Multiple Spacecraft Interferometers

NASA Technical Reports Server (NTRS)

Surka, Derek M.; Crawley, Edward F.

1996-01-01

Structurally connected and multiple spacecraft interferometers are compared in an attempt to establish the maximum baseline (referred to as the "cross-over baseline") for which it is preferable to operate a single-structure interferometer in space rather than an interferometer composed of numerous, smaller spacecraft. This comparison is made using the total launched mass of each configuration as the comparison metric. A framework of study within which structurally connected and multiple spacecraft interferometers can be compared is presented in block diagram form. This methodology is then applied to twenty-two different combinations of trade space parameters to investigate the effects of different orbits, orientations, truss materials, propellants, attitude control actuators, onboard disturbance sources, and performance requirements on the cross-over baseline. Rotating interferometers and the potential advantages of adding active structural control to the connected truss of the structurally connected interferometer are also examined. The minimum mass design of the structurally connected interferometer that meets all performance-requirements and satisfies all imposed constraints is determined as a function of baseline. This minimum mass design is then compared to the design of the multiple spacecraft interferometer. It is discovered that the design of the minimum mass structurally connected interferometer that meets all performance requirements and constraints in solar orbit is limited by the minimum allowable aspect ratio, areal density, and gage of the struts. In the formulation of the problem used in this study, there is no advantage to adding active structural control to the truss for interferometers in solar orbit. The cross-over baseline for missions of practical duration (ranging from one week to thirty years) in solar orbit is approximately 400 m for non-rotating interferometers and 650 m for rotating interferometers.

Structure and Composition of Vegetation of Longleaf Pine Plantations Compared to Natural Stands Occurring Along an Environmental Gradient at the Savannah River Site

Treesearch

Gregory P. Smith; Victor B. Shelburne; Joan L. Walker

2002-01-01

Fifty-four plots in 33-43 year old longleaf pine plantations were compared to 30 remnant plots in longleaf stands on the Savannah River Site in South Carolina. Within these stands, the structure and composition of primarily the herb layer relative to a presumed soil moisture or soil texture gradient was studied using the North Carolina Vegetation Survey methodology....

Comparative Toxicity of Selected Aviation Fuels as Measured by Insect Bioassay

DTIC Science & Technology

1982-07-01

structure in termites , ants, and bees can be used to contrast the toxicity of a compound. A comparative study of toxicity can also be made using a...and also serve as sex pheromones , kairomones, and defensive compounds. Cuticular hydrocarbons vary significantly in structure and amount by species...in flour beetles. Flour beetles contain hydrocarbons which function as sex pheromones and also contain a significant amount of 1-pentadecene which

Nanosize Fe x O y @SBA-3: A Comparative Study Between Conventional and Microwave Assisted Synthesis.

PubMed

Barik, Sunita; Badamali, Sushanta K; Sahoo, Sagarika; Behera, Nandakishor; Dapurkar, Sudhir E

2018-01-01

The present study is focussed on development of highly dispersed nanosize iron oxide (FexOy) particles within the uniform mesopore channels of SBA-3. Herein we report a comparative study between conventional incipient wetness and microwave assisted synthesis routes adopted to devise nanoparticles. The developed materials are characterised by following X-ray diffraction, high resolution transmission electron microscopy, proton induced X-ray emission, diffuse reflectance UV-visible spectroscopy, thermogravimetry and Fourier transform infrared spectroscopy. Mesoporous siliceous SBA-3 was prepared at room temperature to obtain samples with good crystallinity and ordered pore structure. Pore channels of SBA-3 were used as nanoreactor for developing iron oxide nanoparticles. Iron oxide nanoparticles developed under microwave activation showed uniform distribution within the SBA-3 structure along with retaining the orderness of the pore architecture. On the contrary, iron oxides developed under incipient wetness method followed by conventional heating resulted in agglomeration of nanoparticles along with significant loss in SBA-3 pore structure. Proton induced X-ray emission studies revealed the extremely high purity of the samples and almost thrice higher amount of iron oxide particles are encapsulated within the host by microwave assisted preparation as compared to incipient/conventional heating method.

A Comparative Study of Adolescent Risk Assessment Instruments: Predictive and Incremental Validity

ERIC Educational Resources Information Center

Welsh, Jennifer L.; Schmidt, Fred; McKinnon, Lauren; Chattha, H. K.; Meyers, Joanna R.

2008-01-01

Promising new adolescent risk assessment tools are being incorporated into clinical practice but currently possess limited evidence of predictive validity regarding their individual and/or combined use in risk assessments. The current study compares three structured adolescent risk instruments, Youth Level of Service/Case Management Inventory…

The SAVRY Improves Prediction of Reoffending: A Naturalistic Longitudinal Comparative Study

ERIC Educational Resources Information Center

Åström, Therese; Gumpert, Clara Hellner; Andershed, Anna-Karin; Forster, Martin

2017-01-01

Purpose: This study investigated the utility of the risk assessment "Structured Assessment of Violence Risk in Youth" (SAVRY) within the social services in Stockholm County, Sweden. Method: SAVRY assessments of 56 adolescents were compared to assessments guided by another instrument (Adolescent Drug Abuse Diagnosis [ADAD]; n = 38) and…

Research Governance and the Role of Evaluation: A Comparative Study

ERIC Educational Resources Information Center

Molas-Gallart, Jordi

2012-01-01

Through a comparative study of the United Kingdom and Spain, this article addresses the effect of different research governance structures on the functioning and uses of research evaluation. It distinguishes three main evaluation uses: distributive, improvement, and controlling. Research evaluation in the United Kingdom plays important…

Rclick: a web server for comparison of RNA 3D structures.

PubMed

Nguyen, Minh N; Verma, Chandra

2015-03-15

RNA molecules play important roles in key biological processes in the cell and are becoming attractive for developing therapeutic applications. Since the function of RNA depends on its structure and dynamics, comparing and classifying the RNA 3D structures is of crucial importance to molecular biology. In this study, we have developed Rclick, a web server that is capable of superimposing RNA 3D structures by using clique matching and 3D least-squares fitting. Our server Rclick has been benchmarked and compared with other popular servers and methods for RNA structural alignments. In most cases, Rclick alignments were better in terms of structure overlap. Our server also recognizes conformational changes between structures. For this purpose, the server produces complementary alignments to maximize the extent of detectable similarity. Various examples showcase the utility of our web server for comparison of RNA, RNA-protein complexes and RNA-ligand structures. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Gaia: automated quality assessment of protein structure models.

PubMed

Kota, Pradeep; Ding, Feng; Ramachandran, Srinivas; Dokholyan, Nikolay V

2011-08-15

Increasing use of structural modeling for understanding structure-function relationships in proteins has led to the need to ensure that the protein models being used are of acceptable quality. Quality of a given protein structure can be assessed by comparing various intrinsic structural properties of the protein to those observed in high-resolution protein structures. In this study, we present tools to compare a given structure to high-resolution crystal structures. We assess packing by calculating the total void volume, the percentage of unsatisfied hydrogen bonds, the number of steric clashes and the scaling of the accessible surface area. We assess covalent geometry by determining bond lengths, angles, dihedrals and rotamers. The statistical parameters for the above measures, obtained from high-resolution crystal structures enable us to provide a quality-score that points to specific areas where a given protein structural model needs improvement. We provide these tools that appraise protein structures in the form of a web server Gaia (http://chiron.dokhlab.org). Gaia evaluates the packing and covalent geometry of a given protein structure and provides quantitative comparison of the given structure to high-resolution crystal structures. dokh@unc.edu Supplementary data are available at Bioinformatics online.

Visualization of RNA structure models within the Integrative Genomics Viewer.

PubMed

Busan, Steven; Weeks, Kevin M

2017-07-01

Analyses of the interrelationships between RNA structure and function are increasingly important components of genomic studies. The SHAPE-MaP strategy enables accurate RNA structure probing and realistic structure modeling of kilobase-length noncoding RNAs and mRNAs. Existing tools for visualizing RNA structure models are not suitable for efficient analysis of long, structurally heterogeneous RNAs. In addition, structure models are often advantageously interpreted in the context of other experimental data and gene annotation information, for which few tools currently exist. We have developed a module within the widely used and well supported open-source Integrative Genomics Viewer (IGV) that allows visualization of SHAPE and other chemical probing data, including raw reactivities, data-driven structural entropies, and data-constrained base-pair secondary structure models, in context with linear genomic data tracks. We illustrate the usefulness of visualizing RNA structure in the IGV by exploring structure models for a large viral RNA genome, comparing bacterial mRNA structure in cells with its structure under cell- and protein-free conditions, and comparing a noncoding RNA structure modeled using SHAPE data with a base-pairing model inferred through sequence covariation analysis. © 2017 Busan and Weeks; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Comments on Method in Comparative Higher Education.

ERIC Educational Resources Information Center

Wasser, Henry

The methodologies employed in comparative higher education and comparative education are briefly summarized and analyzed. Weaknesses of the following approaches used by scholars/researchers in the field are identified: (1) locating decision-making structures and relations in broadly differentiated aggregations of systems; (2) case study; (3)…

The leader peptide of mutacin 1140 has distinct structural components compared to related class I lantibiotics

PubMed Central

Escano, Jerome; Stauffer, Byron; Brennan, Jacob; Bullock, Monica; Smith, Leif

2014-01-01

Lantibiotics are ribosomally synthesized peptide antibiotics composed of an N-terminal leader peptide that promotes the core peptide's interaction with the post translational modification (PTM) enzymes. Following PTMs, mutacin 1140 is transported out of the cell and the leader peptide is cleaved to yield the antibacterial peptide. Mutacin 1140 leader peptide is structurally unique compared to other class I lantibiotic leader peptides. Herein, we further our understanding of the structural differences of mutacin 1140 leader peptide with regard to other class I leader peptides. We have determined that the length of the leader peptide is important for the biosynthesis of mutacin 1140. We have also determined that mutacin 1140 leader peptide contains a novel four amino acid motif compared to related lantibiotics. PTM enzyme recognition of the leader peptide appears to be evolutionarily distinct from related class I lantibiotics. Our study on mutacin 1140 leader peptide provides a basis for future studies aimed at understanding its interaction with the PTM enzymes. PMID:25400246

Comparative study of wet and dry torrefaction of corn stalk and the effect on biomass pyrolysis polygeneration.

PubMed

Wang, Xianhua; Wu, Jing; Chen, Yingquan; Pattiya, Adisak; Yang, Haiping; Chen, Hanping

2018-06-01

Wet torrefaction (WT) possesses some advantages over dry torrefaction (DT). In this study, a comparative analysis of torrefied corn stalk from WT and DT was conducted along with an investigation of their pyrolysis properties under optimal conditions for biomass pyrolysis polygeneration. Compared with DT, WT removed 98% of the ash and retained twice the amount of hydrogen. The impacts of DT and WT on the biomass macromolecular structure was also found to be different using two-dimensional perturbation correlation infrared spectroscopy (2D-PCIS). WT preserved the active hydroxyl groups and rearranged the macromolecule structure to allow cellulose to be more ordered, while DT removed these active hydroxyl groups and formed inter-crosslinking structures in macromolecules. Correspondingly, the bio-char yield after WT was lower than DT but the bio-char quality was upgraded due to high ash removal. Furthermore, higher bio-oil yield, higher sugar content, and higher H 2 generation, were obtained after WT. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Screened Hybrid DFT Study of Actinide Oxides, Nitrides, and Carbides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wen, Xiaodong; Martin, Richard L.; Scuseria, Gustavo E.

2013-06-27

A systematic study of the structural, electronic, and magnetic properties of actinide oxides, nitrides, and carbides (AnX1–2 with X = C, N, O) is performed using the Heyd–Scuseria–Ernzerhof (HSE) hybrid functional. Our computed results show that the screened hybrid HSE functional gives a good description of the electronic and structural properties of actinide dioxides (strongly correlated insulators) when compared with available experimental data. However, there are still some problems reproducing the electronic properties of actinide nitrides and carbides (strongly correlated metals). In addition, in order to compare with the results by HSE, the structures, electronic, and magnetic properties of thesemore » actinide compounds are also investigated in the PBE and PBE+U approximation. Interestingly, the density of states of UN obtained with PBE compares well with the experimental photoemission spectra, in contrast to the hybrid approximation. This is presumably related to the need of additional screening in the Hartree–Fock exchange term of the metallic phases.« less

Three-dimensional fluid-structure interaction case study on cubical fluid cavity with flexible bottom

NASA Astrophysics Data System (ADS)

Ghelardi, Stefano; Rizzo, Cesare; Villa, Diego

2017-12-01

In this paper, we report our study on a numerical fluid-structure interaction problem originally presented by Mok et al. (2001) in two dimensions and later studied in three dimensions by Valdés Vazquez (2007), Lombardi (2012), and Trimarchi (2012). We focus on a 3D test case in which we evaluated the sensitivity of several input parameters on the fluid and structural results. In particular, this analysis provides a starting point from which we can look deeper into specific aspects of these simulations and analyze more realistic cases, e.g., in sails design. In this study, using the commercial software ADINA™, we addressed a well-known unsteadiness problem comprising a square box representing the fluid domain with a flexible bottom modeled with structural shell elements. We compared data from previously published work whose authors used the same numerical approach, i.e., a partitioned approach coupling a finite volume solver (for the fluid domain) and a finite element solver (for the solid domain). Specifically, we established several benchmarks and made comparisons with respect to fluid and solid meshes, structural element types, and structural damping, as well as solution algorithms. Moreover, we compared our method with a monolithic finite element solution method. Our comparisons of new and old results provide an outline of best practices for such simulations.

Structural Concepts Study of Non-circular Fuselage Configurations

NASA Technical Reports Server (NTRS)

Mukhopadhyay, Vivel

1996-01-01

A preliminary study of structural concepts for noncircular fuselage configurations is presented. For an unconventional flying-wing type aircraft, in which the fuselage is inside the wing, multiple fuselage bays with non-circular sections need to be considered. In a conventional circular fuselage section, internal pressure is carried efficiently by a thin skin via hoop tension. If the section is non-circular, internal pressure loads also induce large bending stresses. The structure must also withstand additional bending and compression loads from aerodynamic and gravitational forces. Flat and vaulted shell structural configurations for such an unconventional, non-circular pressurized fuselage of a large flying-wing were studied. A deep honeycomb sandwich-shell and a ribbed double-wall shell construction were considered. Combinations of these structural concepts were analyzed using both analytical and simple finite element models of isolated sections for a comparative conceptual study. Weight, stress, and deflection results were compared to identify a suitable configuration for detailed analyses. The flat sandwich-shell concept was found preferable to the vaulted shell concept due to its superior buckling stiffness. Vaulted double-skin ribbed shell configurations were found to be superior due to their weight savings, load diffusion, and fail-safe features. The vaulted double-skin ribbed shell structure concept was also analyzed for an integrated wing-fuselage finite element model. Additional problem areas such as wing-fuselage junction and pressure-bearing spar were identified.

Differentiate responses of soil structure to natural vegetation and artificial plantation in landslide hazard region of the West Qinling Mountains, China

NASA Astrophysics Data System (ADS)

Wang, X.; Huang, Z.; Zhao, Y.; Hong, M.

2017-12-01

Natural vegetation and artificial plantation are the most important measures for ecological restoration in soil erosion and landslide hazard-prone regions of China. Previous studies have demonstrated that both measures can significantly change the soil structure and decrease soil and water erosion. Few reports have compared the effects of the two contrasting measures on mechanical and hydrological properties and further tested the differentiate responses of soil structure. In the study areas, two vegetation restoration measures-natural vegetation restoration (NVR) and artificial plantation restoration (APR) compared with control site, with similar topographical and geological backgrounds were selected to investigate the different effects on soil structure based on eight-year ecological restoration projects. The results showed that the surface vegetation played an important role in releasing soil erosion and enhance soil structure stability through change the soil aggregates (SA) and total soil porosity (TSP). The SA<0.25mm content in NVR (36.13%) was higher than that in APR (32.14%). The study indicated that SA and TSP were the principal components (PCs) related to soil structure variation. Soil organic carbon, soil water retention, clay and vegetation biomass were more strongly correlated with the PCs in NVR than those in APR. The study indicated that NVR was more beneficial for soil structure stability than APR. These findings will provide a theoretical basis for the decisions around reasonable land use for ecological restoration and conservation in geological hazard-prone regions.

Comparative study on diagonal equivalent methods of masonry infill panel

NASA Astrophysics Data System (ADS)

Amalia, Aniendhita Rizki; Iranata, Data

2017-06-01

Infrastructure construction in earthquake prone area needs good design process, including modeling a structure in a correct way to reduce damages caused by an earthquake. Earthquakes cause many damages e.g. collapsed buildings that are dangerous. An incorrect modeling in design process certainly affects the structure's ability in responding to load, i.e. an earthquake load, and it needs to be paid attention to in order to reduce damages and fatalities. A correct modeling considers every aspect that affects the strength of a building, including stiffness of resisting lateral loads caused by an earthquake. Most of structural analyses still use open frame method that does not consider the effect of stiffness of masonry panel to the stiffness and strength of the whole structure. Effect of masonry panel is usually not included in design process, but the presence of this panel greatly affects behavior of the building in responding to an earthquake. In worst case scenario, it can even cause the building to collapse as what has been reported after great earthquakes worldwide. Modeling a structure with masonry panel as consideration can be performed by designing the panel as compression brace or shell element. In designing masonry panel as a compression brace, there are fourteen methods popular to be used by structure designers formulated by Saneinejad-Hobbs, Holmes, Stafford-Smith, Mainstones, Mainstones-Weeks, Bazan-Meli, Liauw Kwan, Paulay and Priestley, FEMA 356, Durani Luo, Hendry, Al-Chaar, Papia and Chen-Iranata. Every method has its own equation and parameters to use, therefore the model of every method was compared to results of experimental test to see which one gives closer values. Moreover, those methods also need to be compared to the open frame to see if they can result values within limits. Experimental test that was used in comparing all methods was taken from Mehrabi's research (Fig. 1), which was a prototype of a frame in a structure with 0.5 scale and the ratio of height to width of 1 to 1.5. Load used in the experiment was based on Uniform Building Code (UBC) 1991. Every method compared was calculated first to get equivalent diagonal strut width. The second step was modelling method using structure analysis software as a frame with a diagonal in a linear mode. The linear mode was chosen based on structure analysis commonly used by structure designers. The frame was loaded and for every model, its load and deformation values were identified. The values of load - deformation of every method were compared to those of experimental test specimen by Mehrabi and open frame. From comparative study performed, Holmes' and Bazan-Meli's equations gave results the closest to the experimental test specimen by Mehrabi. Other equations that gave close values within the limit (by comparing it to the open frame) are Saneinejad-Hobbs, Stafford-Smith, Bazan-Meli, Liauw Kwan, Paulay and Priestley, FEMA 356, Durani Luo, Hendry, Papia and Chen-Iranata.

Effect of Verb Argument Structure on Picture Naming in Children with and without Specific Language Impairment (SLI)

ERIC Educational Resources Information Center

Andreu, Llorenc; Sanz-Torrent, Monica; Legaz, Lucia Buil; MacWhinney, Brian

2012-01-01

Background: This study investigated verb argument structure effects in children with specific language impairment (SLI). Aims: A picture-naming paradigm was used to compare the response times and naming accuracy for nouns and verbs with differing argument structure between Spanish-speaking children with and without language impairment. Methods…

The Effects of Competitive vs. Cooperative Structures on Subsequent Productivity in Boys with Psychosocial Disorders.

ERIC Educational Resources Information Center

Nelson, David L.; Peterson, Cindee Q.

1991-01-01

A study compared three subject groups structured for competition to three subject groups structured for cooperation. Thirty-six 8- to 17-year-old males residing in a treatment center for nonpsychotic psychosocial disorders participated in competitive and cooperative dice games. Results did not support the hypothesis that a cooperative experience…

Canopy structure on forest lands in western Oregon: differences among forest types and stand ages

Treesearch

Anne C.S. McIntosh; Andrew N. Gray; Steven L. Garman

2009-01-01

Canopy structure is an important attribute affecting economic and ecological values of forests in the Pacific Northwest. However, canopy cover and vertical layering are rarely measured directly; they are usually inferred from other forest measurements. In this study, we quantified and compared vertical and horizontal patterns of tree canopy structure and understory...

Comparative Effectiveness of Alternative Administrative Structures. Final Report on a Pilot Investigation. Programme on Institutional Management in Higher Education.

ERIC Educational Resources Information Center

Rivett, B. H. P.; And Others

Initial objectives of this pilot study were to: define the effectiveness and structure of administration in institutions of higher education; explore and identify measures of administrative effectiveness and structure; test the practicability of such definitions and measures against on-going processes at Sussex University; direct, coordinate, and…

A comparison of canopy structure measures for predicting height growth of underplanted seedlings

Treesearch

John M. Lhotka; Edward F. Loewenstein

2013-01-01

The study compares the relationship between 15 measures of canopy structure and height growth of underplanted yellow-poplar (Liriodendron tulipifera L.) seedlings. Investigators used 4 midstory removal intensities to create a structural gradient across fifty 0.05-ha experimental plots; removals resulted in a range of canopy cover between 51 to 96...

Testing for Measurement and Structural Equivalence in Large-Scale Cross-Cultural Studies: Addressing the Issue of Nonequivalence

ERIC Educational Resources Information Center

Byrne, Barbara M.; van de Vijver, Fons J. R.

2010-01-01

A critical assumption in cross-cultural comparative research is that the instrument measures the same construct(s) in exactly the same way across all groups (i.e., the instrument is measurement and structurally equivalent). Structural equation modeling (SEM) procedures are commonly used in testing these assumptions of multigroup equivalence.…

The Role of Structured Cooperative Learning Groups for Enhancing Chinese Primary Students' Reading Comprehension

ERIC Educational Resources Information Center

Law, Yin-Kum

2014-01-01

The present study aimed to compare the effectiveness of two types of cooperative learning groups used in reciprocal teaching (RT) classes (i.e. high-structured vs. low-structured groups) for enhancing students' reading comprehension. The participants were 235 Hong Kong Chinese Grade 6 students in nine classes. Reading comprehension tests and…

Redesigning of a Canard Control Surface of an Advanced Fighter Aircraft: Effect on Buckling and Aerodynamic Behavior

NASA Astrophysics Data System (ADS)

Shrivastava, Sachin; Mohite, P. M.

2015-01-01

A redesign of canard control-surface of an advanced all-metallic fighter aircraft was carried out by using carbon fibre composite (CFC) for ribs and panels. In this study ply-orientations of CFC structure are optimized using a Genetic-Algorithm (GA) with an objective function to have minimum failure index (FI) according to Tsai-Wu failure criterion. The redesigned CFC structure was sufficiently strong to withstand aerodynamic loads from stress and deflection points of view. Now, in the present work CFC canard structure has been studied for its buckling strength in comparison to existing metallic design. In this study, the existing metallic design was found to be weak in buckling. Upon a detailed investigation, it was revealed that there are reported failures in the vicinity of zones where initial buckling modes are excited as predicted by the finite element based buckling analysis. In view of buckling failures, the redesigned CFC structure is sufficiently reinforced with stringers at specific locations. After providing reinforcements against buckling, the twist and the camber variations of the airfoil are checked and compared with existing structure data. Finally, the modal analysis has been carried out to compare the variation in excitation frequency due to material change. The CFC structure thus redesigned is safe from buckling and aerodynamic aspects as well.

[Evaluation of the performance of the logistics management system of malaria control resources in the Littoral Department, Benin, in 2017].

PubMed

Ouro-Koura, Abdou-Rahim; Sopoh, Emmanuel Ghislain; Sossa, Jerôme Charles; Glèlè-Ahanhanzo, Yolaine; Agueh, Victoire; Ouendo, Edgard-Marius; Ouedraogo, Laurent

2018-01-01

This study aimed to evaluate the performance of the logistics management system (LMS) of malaria control (MC) resources in the Littoral Department, Benin, in 2017. In June 2017, we conducted a cross-sectional evaluative study focusing on the structures for the storage and the disposal of MC resources as well as on staff involved in their management. The performance of the the logistics management system was evaluated on the basis of the observed compliance of the components and sub-components of the "Structure", the "Process" and the "Results" with the norms and standards defined by the Ministry of Health. A total of 36 structures were investigated and secondary target was surveyed. It followed that 52,78% of the structures for the storage and the disposal of MC resources met the requirements for resources storage while only 33.33% of MC resources management staff were trained in logistics management. The performance of the logistics management system of MC resources was inadequate (compliance 59,13 % compared to the expected score). The structure, as well as the process were non-compliant with the standards ( 60,20% and 73.22% compared to the expected score respectively), leading to negative results (41.53% compared to the expected score). The most inadequate sub-component was the logistics management information system (LMIS). This study highlights the role of LMS for better performance of MC resources management. Particular attention should be given to this component.

The Latent Structures of the Learning and Study Strategies Inventory (LASSI): A Comparative Analysis.

ERIC Educational Resources Information Center

Obiekwe, Jerry C.

The first purpose of this study was to analyze the results of the confirmatory factor analyses, via EQS, with regard to the latent structures of the Learning and Study Strategies Inventory (LASSI) (C. Weinstein, D. Palmer, and A. Schulte, 1987) as proposed by S. Olejnik and S. Nist (1992), A. Olivarez and M. Tallent-Runnels (1994), B. Olaussen and…

Assessing analytical comparability of biosimilars: GCSF as a case study.

PubMed

Nupur, Neh; Singh, Sumit Kumar; Narula, Gunjan; Rathore, Anurag S

2016-10-01

The biosimilar industry is witnessing an unprecedented growth with the newer therapeutics increasing in complexity over time. A key step towards development of a biosimilar is to establish analytical comparability with the innovator product, which would otherwise affect the safety/efficacy profile of the product. Choosing appropriate analytical tools that can fulfil this objective by qualitatively and/or quantitatively assessing the critical quality attributes (CQAs) of the product is highly critical for establishing equivalence. These CQAs cover the primary and higher order structures of the product, product related variants and impurities, as well as process related impurities, and host cell related impurities. In the present work, we use such an analytical platform for assessing comparability of five approved Granulocyte Colony Stimulating Factor (GCSF) biosimilars (Emgrast, Lupifil, Colstim, Neukine and Grafeel) to the innovator product, Neupogen(®). The comparability studies involve assessing structural homogeneity, identity, secondary structure, and product related modifications. Physicochemical analytical tools include peptide mapping with mass determination, circular dichroism (CD) spectroscopy, reverse phase chromatography (RPC) and size exclusion chromatography (SEC) have been used in this exercise. Bioactivity assessment include comparison of relative potency through in vitro cell proliferation assays. The results from extensive analytical examination offer robust evidence of structural and biological similarity of the products under consideration with the pertinent innovator product. For the most part, the biosimilar drugs were found to be comparable to the innovator drug anomaly that was identified was that three of the biosimilars had a typical variant which was reported as an oxidized species in the literature. But, upon further investigation using RPC-FLD and ESI-MS we found that this is likely a conformational variant of the biotherapeutic been studied. Copyright © 2016 Elsevier B.V. All rights reserved.

Unintentional fall-related mortality in the elderly: comparing patterns in two countries with different demographic structure

PubMed Central

Majdan, Marek; Mauritz, Walter

2015-01-01

Objectives Falls are among the major external causes of unintentional injury and injury-related mortality in the elderly. The aim of this study was to compare the patterns of unintentional fall-related mortalities in two countries with different demographic structure: Slovakia and Austria in 2003–2010. Methods A study was conducted using death certificate data, trends of fall-related mortality in the elderly (over 65 years) in Austria and Slovakia were compared. Crude and age-standardised mortality rates were calculated. Rate ratios were used to quantify differences based on age, sex and country. The role of demographic structure and population ageing was considered. Results The annual average crude mortality for Slovakia was 28.82, for Austria 54.19 per 100 000 person-years. Increasing rates were observed towards higher age in both countries. Males had higher mortality than females (1.18 times higher in Austria, 2.4 higher in Slovakia). In ages over 75 years rates were significantly higher in Austria, compared to Slovakia. Injuries to head (in males) and hip (in females) were most commonly the underlying cause of death. The proportion of populations over 65 and over 80 and rate of their increase were higher in Austria than in Slovakia. Conclusions We conclude that higher proportions of the elderly population of Austria could have contributed to the higher fall-related mortality rates compared to Slovakia, especially in females over 80 years. Our study quantified the differences between two countries with different structure of the elderly population and these findings could be used in planning future needs of health and social services and to plan prevention in countries where a rapid increase in age of the population can be foreseen. PMID:26270950

Chain end distribution of block copolymer in two-dimensional microphase-separated structure studied by scanning near-field optical microscopy.

PubMed

Sekine, Ryojun; Aoki, Hiroyuki; Ito, Shinzaburo

2009-10-01

The chain end distribution of a block copolymer in a two-dimensional microphase-separated structure was studied by scanning near-field optical microscopy (SNOM). In the monolayer of poly(octadecyl methacrylate)-block-poly(isobutyl methacrylate) (PODMA-b-PiBMA), the free end of the PiBMA subchain was directly observed by SNOM, and the spatial distributions of the whole block and the chain end are examined and compared with the convolution of the point spread function of the microscope and distribution function of the model structures. It was found that the chain end distribution of the block copolymer confined in two dimensions has a peak near the domain center, being concentrated in the narrower region, as compared with three-dimensional systems.

Persistent post-traumatic headache vs. migraine: an MRI study demonstrating differences in brain structure.

PubMed

Schwedt, Todd J; Chong, Catherine D; Peplinski, Jacob; Ross, Katherine; Berisha, Visar

2017-08-22

The majority of individuals with post-traumatic headache have symptoms that are indistinguishable from migraine. The overlap in symptoms amongst these individuals raises the question as to whether post-traumatic headache has a unique pathophysiology or if head trauma triggers migraine. The objective of this study was to compare brain structure in individuals with persistent post-traumatic headache (i.e. headache lasting at least 3 months following a traumatic brain injury) attributed to mild traumatic brain injury to that of individuals with migraine. Twenty-eight individuals with persistent post-traumatic headache attributed to mild traumatic brain injury and 28 individuals with migraine underwent brain magnetic resonance imaging on a 3 T scanner. Regional volumes, cortical thickness, surface area and curvature measurements were calculated from T1-weighted sequences and compared between subject groups using ANCOVA. MRI data from 28 healthy control subjects were used to interpret the differences in brain structure between migraine and persistent post-traumatic headache. Differences in regional volumes, cortical thickness, surface area and brain curvature were identified when comparing the group of individuals with persistent post-traumatic headache to the group with migraine. Structure was different between groups for regions within the right lateral orbitofrontal lobe, left caudal middle frontal lobe, left superior frontal lobe, left precuneus and right supramarginal gyrus (p < .05). Considering these regions only, there were differences between individuals with persistent post-traumatic headache and healthy controls within the right lateral orbitofrontal lobe, right supramarginal gyrus, and left superior frontal lobe and no differences when comparing the migraine cohort to healthy controls. In conclusion, persistent post-traumatic headache and migraine are associated with differences in brain structure, perhaps suggesting differences in their underlying pathophysiology. Additional studies are needed to further delineate similarities and differences in brain structure and function that are associated with post-traumatic headache and migraine and to determine their specificity for each of the headache types.

Leisure activities are linked to mental health benefits by providing time structure: comparing employed, unemployed and homemakers

PubMed Central

Goodman, William K; Geiger, Ashley M; Wolf, Jutta M

2017-01-01

Background Unemployment has consistently been linked to negative mental health outcomes, emphasising the need to characterise the underlying mechanisms. The current study aimed at testing whether compared with other employment groups, fewer leisure activities observed in unemployment may contribute to elevated risk for negative mental health via loss of time structure. Methods Depressive symptoms (Center for Epidemiologic Studies Depression), leisure activities (exercise, self-focused, social), and time structure (Time Structure Questionnaire (TSQ)) were assessed cross-sectionally in 406 participants (unemployed=155, employed=140, homemakers=111) recruited through Amazon Mechanical Turk. Results Controlling for gender and age, structural equation modelling revealed time structure partially (employed, homemakers) and fully (unemployed) mediated the relationship between leisure activities and depressive symptoms. With the exception of differential effects for structured routines, all other TSQ factors (sense of purpose, present orientation, effective organisation and persistence) contributed significantly to all models. Conclusions These findings support the idea that especially for the unemployed, leisure activities impose their mental health benefits through increasing individuals’ perception of spending their time effectively. Social leisure activities that provide a sense of daily structure may thereby be a particularly promising low-cost intervention to improve mental health in this population. PMID:27298424

Beyond the Flipped Classroom: A Highly Interactive Cloud-Classroom (HIC) Embedded into Basic Materials Science Courses

ERIC Educational Resources Information Center

Liou, Wei-Kai; Bhagat, Kaushal Kumar; Chang, Chun-Yen

2016-01-01

The present study compares the highly interactive cloud-classroom (HIC) system with traditional methods of teaching materials science that utilize crystal structure picture or real crystal structure model, in order to examine its learning effectiveness across three dimensions: knowledge, comprehension and application. The aim of this study was to…

A Novice-Expert Study of Modeling Skills and Knowledge Structures about Air Quality

ERIC Educational Resources Information Center

Hsu, Ying-Shao; Lin, Li-Fen; Wu, Hsin-Kai; Lee, Dai-Ying; Hwang, Fu-Kwun

2012-01-01

This study compared modeling skills and knowledge structures of four groups as seen in their understanding of air quality. The four groups were: experts (atmospheric scientists), intermediates (upper-level graduate students in a different field), advanced novices (talented 11th and 12th graders), and novices (10th graders). It was found that when…

Quantifying the relationship between sequence and three-dimensional structure conservation in RNA

PubMed Central

2010-01-01

Background In recent years, the number of available RNA structures has rapidly grown reflecting the increased interest on RNA biology. Similarly to the studies carried out two decades ago for proteins, which gave the fundamental grounds for developing comparative protein structure prediction methods, we are now able to quantify the relationship between sequence and structure conservation in RNA. Results Here we introduce an all-against-all sequence- and three-dimensional (3D) structure-based comparison of a representative set of RNA structures, which have allowed us to quantitatively confirm that: (i) there is a measurable relationship between sequence and structure conservation that weakens for alignments resulting in below 60% sequence identity, (ii) evolution tends to conserve more RNA structure than sequence, and (iii) there is a twilight zone for RNA homology detection. Discussion The computational analysis here presented quantitatively describes the relationship between sequence and structure for RNA molecules and defines a twilight zone region for detecting RNA homology. Our work could represent the theoretical basis and limitations for future developments in comparative RNA 3D structure prediction. PMID:20550657

A classification of ecological boundaries

USGS Publications Warehouse

Strayer, D.L.; Power, M.E.; Fagan, W.F.; Pickett, S.T.A.; Belnap, J.

2003-01-01

Ecologists use the term boundary to refer to a wide range of real and conceptual structures. Because imprecise terminology may impede the search for general patterns and theories about ecological boundaries, we present a classification of the attributes of ecological boundaries to aid in communication and theory development. Ecological boundaries may differ in their origin and maintenance, their spatial structure, their function, and their temporal dynamics. A classification system based on these attributes should help ecologists determine whether boundaries are truly comparable. This system can be applied when comparing empirical studies, comparing theories, and testing theoretical predictions against empirical results.

Coherent structures shed by multiscale cut-in trailing edge serrations on lifting wings

NASA Astrophysics Data System (ADS)

Prigent, S. L.; Buxton, O. R. H.; Bruce, P. J. K.

2017-07-01

This experimental study presents the effect of multiscale cut-in trailing edge serrations on the coherent structures shed into the wake of a lifting wing. Two-probe span-wise hot-wire traverses are performed to study spectra, coherence, and phase shift. In addition, planar particle image velocimetry is used to study the spatio-temporal structure of the vortices shed by the airfoils. Compared with a single tone sinusoidal serration, the multiscale ones reduce the vortex shedding energy as well as the span-wise coherence. Results indicate that the vortex shedding is locked into an arch-shaped cell structure. This structure is weakened by the multiscale patterns, which explains the reduction in both shedding energy and coherence.

The study on molecular structure and microbiological activity of alkali metal 3-hydroxyphenylycetates

NASA Astrophysics Data System (ADS)

Samsonowicz, M.; Regulska, E.; Kowczyk-Sadowy, M.; Butarewicz, A.; Lewandowski, W.

2017-10-01

The biological activity of chemical compounds depends on their molecular structure. In this paper molecular structure of 3-hydroxyphenylacetates in comparison to 3-hydroxyphenylacetic acid was studied. FT-IR, FT-Raman and NMR spectroscopy and density functional theory (DFT) calculations was used. The B3LYP/6-311++G(d,p) hybrid functional method was used to calculate optimized geometrical structures of studied compounds. The Mulliken, APT, MK, ChelpG and NBO atomic charges as well as dipole moment and energy values were calculated. Theoretical chemical shifts in NMR spectra and the wavenumbers and intensities of the bands in vibrational spectra were analyzed. Calculated parameters were compared to experimental characteristic of studied compounds. Microbiological analysis of studied compounds was performed relative to: Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Klebsiella oxytoca. The relationship between spectroscopic and structure parameters of studied compounds in regard to their activity was analyzed.

Exploration of freely available web-interfaces for comparative homology modelling of microbial proteins.

PubMed

Nema, Vijay; Pal, Sudhir Kumar

2013-01-01

This study was conducted to find the best suited freely available software for modelling of proteins by taking a few sample proteins. The proteins used were small to big in size with available crystal structures for the purpose of benchmarking. Key players like Phyre2, Swiss-Model, CPHmodels-3.0, Homer, (PS)2, (PS)(2)-V(2), Modweb were used for the comparison and model generation. Benchmarking process was done for four proteins, Icl, InhA, and KatG of Mycobacterium tuberculosis and RpoB of Thermus Thermophilus to get the most suited software. Parameters compared during analysis gave relatively better values for Phyre2 and Swiss-Model. This comparative study gave the information that Phyre2 and Swiss-Model make good models of small and large proteins as compared to other screened software. Other software was also good but is often not very efficient in providing full-length and properly folded structure.

Comparative structure-function characterization of the saposin-like domains from potato, barley, cardoon and Arabidopsis aspartic proteases.

PubMed

Bryksa, Brian C; Grahame, Douglas A; Yada, Rickey Y

2017-05-01

The present study characterized the aspartic protease saposin-like domains of four plant species, Solanum tuberosum (potato), Hordeum vulgare L. (barley), Cynara cardunculus L. (cardoon; artichoke thistle) and Arabidopsis thaliana, in terms of bilayer disruption and fusion, and structure pH-dependence. Comparison of the recombinant saposin-like domains revealed that each induced leakage of bilayer vesicles composed of a simple phospholipid mixture with relative rates Arabidopsis>barley>cardoon>potato. When compared for leakage of bilayer composed of a vacuole-like phospholipid mixture, leakage was approximately five times higher for potato saposin-like domain compared to the others. In terms of fusogenic activity, distinctions between particle size profiles were noted among the four proteins, particularly for potato saposin-like domain. Bilayer fusion assays in reducing conditions resulted in altered fusion profiles except in the case of cardoon saposin-like domain which was virtually unchanged. Secondary structure profiles were similar across all four proteins under different pH conditions, although cardoon saposin-like domain appeared to have higher overall helix structure. Furthermore, increases in Trp emission upon protein-bilayer interactions suggested that protein structure rearrangements equilibrated with half-times ranging from 52 to 120s, with cardoon saposin-like domain significantly slower than the other three species. Overall, the present findings serve as a foundation for future studies seeking to delineate protein structural features and motifs in protein-bilayer interactions based upon variability in plant aspartic protease saposin-like domain structures. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative analyses of putative toxin gene homologs from an Old World viper, Daboia russelii

PubMed Central

Krishnan, Neeraja M.

2017-01-01

Availability of snake genome sequences has opened up exciting areas of research on comparative genomics and gene diversity. One of the challenges in studying snake genomes is the acquisition of biological material from live animals, especially from the venomous ones, making the process cumbersome and time-consuming. Here, we report comparative sequence analyses of putative toxin gene homologs from Russell’s viper (Daboia russelii) using whole-genome sequencing data obtained from shed skin. When compared with the major venom proteins in Russell’s viper studied previously, we found 45–100% sequence similarity between the venom proteins and their putative homologs in the skin. Additionally, comparative analyses of 20 putative toxin gene family homologs provided evidence of unique sequence motifs in nerve growth factor (NGF), platelet derived growth factor (PDGF), Kunitz/Bovine pancreatic trypsin inhibitor (Kunitz BPTI), cysteine-rich secretory proteins, antigen 5, andpathogenesis-related1 proteins (CAP) and cysteine-rich secretory protein (CRISP). In those derived proteins, we identified V11 and T35 in the NGF domain; F23 and A29 in the PDGF domain; N69, K2 and A5 in the CAP domain; and Q17 in the CRISP domain to be responsible for differences in the largest pockets across the protein domain structures in crotalines, viperines and elapids from the in silico structure-based analysis. Similarly, residues F10, Y11 and E20 appear to play an important role in the protein structures across the kunitz protein domain of viperids and elapids. Our study highlights the usefulness of shed skin in obtaining good quality high-molecular weight DNA for comparative genomic studies, and provides evidence towards the unique features and evolution of putative venom gene homologs in vipers. PMID:29230357

Numerical investigation of the aerodynamic and structural characteristics of a corrugated wing

NASA Astrophysics Data System (ADS)

Hord, Kyle

Previous experimental studies on static, bio-inspired corrugated wings have shown that they produce favorable aerodynamic properties such as delayed stall compared to streamlined wings and flat plates at high Reynolds numbers (Re ≥ 4x104). The majority of studies have been carried out with scaled models of dragonfly forewings from the Aeshna Cyanea in either wind tunnels or water channels. In this thesis, the aerodynamics of a corrugated airfoil was studied using computational fluid dynamics methods at a low Reynolds number of 1000. Structural analysis was also performed using the commercial software SolidWorks 2009. The flow field is described by solving the incompressible Navier-Stokes equations on an overlapping grid using the pressure-Poisson method. The equations are discretized in space with second-order accurate central differences. Time integration is achieved through the second-order Crank-Nicolson implicit method. The complex vortex structures that form in the corrugated airfoil valleys and around the corrugated airfoil are studied in detail. Comparisons are made with experimental measurements from corrugated wings and also with simulations of a flat plate. Contrary to the studies at high Reynolds numbers, our study shows that at low Reynolds numbers the wing corrugation does not provide any aerodynamic benefit compared to a smoothed flat plate. Instead, the corrugated profile generates more pressure drag which is only partially offset by the reduction of friction drag, leading to more total drag than the flat plate. Structural analysis shows that the wing corrugation can increase the resistance to bending moments on the wing structure. A smoothed structure has to be three times thicker to provide the same stiffness. It was concluded the corrugated wing has the structural benefit to provide the same resistance to bending moments with a much reduced weight.

Revisiting Robustness and Evolvability: Evolution in Weighted Genotype Spaces

PubMed Central

Partha, Raghavendran; Raman, Karthik

2014-01-01

Robustness and evolvability are highly intertwined properties of biological systems. The relationship between these properties determines how biological systems are able to withstand mutations and show variation in response to them. Computational studies have explored the relationship between these two properties using neutral networks of RNA sequences (genotype) and their secondary structures (phenotype) as a model system. However, these studies have assumed every mutation to a sequence to be equally likely; the differences in the likelihood of the occurrence of various mutations, and the consequence of probabilistic nature of the mutations in such a system have previously been ignored. Associating probabilities to mutations essentially results in the weighting of genotype space. We here perform a comparative analysis of weighted and unweighted neutral networks of RNA sequences, and subsequently explore the relationship between robustness and evolvability. We show that assuming an equal likelihood for all mutations (as in an unweighted network), underestimates robustness and overestimates evolvability of a system. In spite of discarding this assumption, we observe that a negative correlation between sequence (genotype) robustness and sequence evolvability persists, and also that structure (phenotype) robustness promotes structure evolvability, as observed in earlier studies using unweighted networks. We also study the effects of base composition bias on robustness and evolvability. Particularly, we explore the association between robustness and evolvability in a sequence space that is AU-rich – sequences with an AU content of 80% or higher, compared to a normal (unbiased) sequence space. We find that evolvability of both sequences and structures in an AU-rich space is lesser compared to the normal space, and robustness higher. We also observe that AU-rich populations evolving on neutral networks of phenotypes, can access less phenotypic variation compared to normal populations evolving on neutral networks. PMID:25390641

Patients' assessment of quality of care in public tertiary hospitals with and without accreditation: comparative cross-sectional study.

PubMed

Aboshaiqah, Ahmad E; Alonazi, Wadi B; Patalagsa, Joel Gonzales

2016-11-01

To compare patients' assessment of quality of care provided by public tertiary hospitals grouped according to accreditation status. Healthcare institutions worldwide are increasingly adopting accreditation as continuing initiative aimed at improving structures, processes and outcomes associated with quality of care. Patients being recipients of health care need to participate in assessing the quality of care they experienced while confined for therapeutic management. Comparative, cross-sectional. Data were collected from patients confined in public tertiary hospitals (n = 517 in four with accreditation and n = 542 in four without accreditation) in Riyadh, Saudi Arabia between February 2011-June 2011. Patients rated key performance indicators grouped under the dimensions of structure, process and outcome. Mann-Whitney U-test, Spearman Correlation Coefficient and coefficient of determination were used in analysing data. Patients in accredited public tertiary hospitals perceived structure, outcome and overall quality of care statistically higher than patients in non-accredited hospitals. No statistical differences were found in process (access and communication) indicators. Accreditation status is marginally associated with structure; outcome; and overall quality of care. The proportion of variance in the ranks of accreditation status explained the proportion of variance in the ranks of structure; outcome; and overall quality of care. The results apparently showed better structure, outcome and overall quality of care in accredited hospitals. Accreditation's association in the overall quality of care apparently remained unclear. Further studies are needed to appreciate the contribution of accreditation. © 2016 John Wiley & Sons Ltd.

Analytical and experimental study of structurally efficient composite hat-stiffened panels loaded in axial compression

NASA Technical Reports Server (NTRS)

Williams, J. G.; Mikulus, M. M., Jr.

1976-01-01

Structural efficiency studies were made to determine the weight saving potential of graphite/epoxy composite structures for compression panel applications. Minimum weight hat-stiffened and open corrugation configurations were synthesized using a nonlinear mathematical programming technique. Selected configurations were built and tested to study local and Euler buckling characteristics. Test results for 23 panels critical in local buckling and six panels critical in Euler buckling are compared with analytical results obtained using the BUCLASP-2 branched plate buckling program. A weight efficiency comparison is made between composite and aluminum compression panels using metal test data generated by the NACA. Theoretical studies indicate that potential weight savings of up to 50% are possible for composite hat-stiffened panels when compared with similar aluminum designs. Weight savings of 32% to 42% were experimentally achieved. Experience suggests that most of the theoretical weight saving potential is available if design deficiencies are eliminated and strict fabrication control is exercised.

An approach to comparative anatomy of the acetabulum from amphibians to primates.

PubMed

Canillas, F; Delgado-Martos, M J; Touza, A; Escario, A; Martos-Rodriguez, A; Delgado-Baeza, E

2011-12-01

The objective of this study was to investigate the anatomy, both macroscopic and microscopic, of the soft tissue internal structures of the hip joint in animal species and in three human hips (an adult and two fetuses). We dissected the hip joints of 16 species and compared the anatomical features of the soft tissue from the respective acetabula. In addition, a histological study was made of the specimens studied. In amphibians, we found a meniscus in the acetabulum, which was not observed in any of the other species studied. The isolated round ligament is observed from birds onwards. In the group of mammals analysed, including the human specimens, we found a meniscoid structure in the acetabular hip joint. Furthermore, we found that the meniscoid structure forms an anatomo-functional unit with the round ligament and the transverse ligament of the coxofemoral joint. These discoveries suggest the participation of the soft tissue anatomy in adaptative changes of species. © 2011 Blackwell Verlag GmbH.

Three-dimensional water impact at normal incidence to a blunt structure

PubMed Central

Cooker, M. J.; Korobkin, A. A.

2016-01-01

The three-dimensional water impact onto a blunt structure with a spreading rectangular contact region is studied. The structure is mounted on a flat rigid plane with the impermeable curved surface of the structure perpendicular to the plane. Before impact, the water region is a rectangular domain of finite thickness bounded from below by the rigid plane and above by the flat free surface. The front free surface of the water region is vertical, representing the front of an advancing steep wave. The water region is initially advancing towards the structure at a constant uniform speed. We are concerned with the slamming loads acting on the surface of the structure during the initial stage of water impact. Air, gravity and surface tension are neglected. The problem is analysed by using some ideas of pressure-impulse theory, but including the time-dependence of the wetted area of the structure. The flow caused by the impact is three-dimensional and incompressible. The distribution of the pressure-impulse (the time-integral of pressure) over the surface of the structure is analysed and compared with the distributions provided by strip theories. The total impulse exerted on the structure during the impact stage is evaluated and compared with numerical and experimental predictions. An example calculation is presented of water impact onto a vertical rigid cylinder. Three-dimensional effects on the slamming loads are the main concern in this study. PMID:27616912

3-D Upper-Mantle Shear Velocity Model Beneath the Contiguous United States Based on Broadband Surface Wave from Ambient Seismic Noise

NASA Astrophysics Data System (ADS)

Xie, Jun; Chu, Risheng; Yang, Yingjie

2018-05-01

Ambient noise seismic tomography has been widely used to study crustal and upper-mantle shear velocity structures. Most studies, however, concentrate on short period (< 50 s) surface wave from ambient noise, while studies using long period surface wave from ambient noise are limited. In this paper, we demonstrate the feasibility of using long-period surface wave from ambient noise to study the lithospheric structure on a continental scale. We use broadband Rayleigh wave phase velocities to obtain a 3-D V S structures beneath the contiguous United States at period band of 10-150 s. During the inversion, 1-D shear wave velocity profile is parameterized using B-spline at each grid point and is inverted with nonlinear Markov Chain Monte Carlo method. Then, a 3-D shear velocity model is constructed by assembling all the 1-D shear velocity profiles. Our model is overall consistent with existing models which are based on multiple datasets or data from earthquakes. Our model along with the other post-USArray models reveal lithosphere structures in the upper mantle, which are consistent with the geological tectonic background (e.g., the craton root and regional upwelling provinces). The model has comparable resolution on lithosphere structures compared with many published results and can be used for future detailed regional or continental studies and analysis.

Cellulose Nanocrystals vs. Cellulose Nanofibrils: A Comparative study on Their Microstructures and Effects as Polymer Reinforcing Agents

Treesearch

Xuezhu Xu; Fei Liu; Long Jiang; J.Y. Zhu; Darrin Haagenson; Dennis P. Wiesenborn

2013-01-01

Both cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) are nanoscale cellulose fibers that have shown reinforcing effects in polymer nanocomposites. CNCs and CNFs are different in shape, size and composition. This study systematically compared their morphologies, crystalline structure, dispersion properties in polyethylene oxide (PEO) matrix, interactions...

First-principles study of the structural properties of Ge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, K.J.; Cohen, M.L.

1986-12-15

With the use of an ab initio pseudopotential method, the structural properties of Ge are investigated at normal and high pressures. The pressure-induced structural phase transitions from cubic diamond to ..beta..-Sn, to simple hexagonal (sh), and to double hexagonal close packed (dhcp) are examined. With the possible exception of the dhcp structure, the calculated transition pressures, transition volumes, and axial ratios are in good agreement with experimental results. We find that sh Ge has characteristics similar to those of sh Si; the bonds between hexagonal layers are stronger than intralayer bonds and the transverse phonon modes become soft near themore » transitions from the sh to ..beta..-Sn and the sh to hcp structures. At normal pressures, we compare the crystal energies for the cubic diamond, hexagonal 2H, and hexagonal 4H structures. Because of the similar sp/sup 3/ bonds in these structures, the structural energy differences are less than about 14 meV, and the 2H and 4H phases are metastable with respect to the cubic diamond structure. The equation of state is also presented and compared with experiment.« less

Heat transfer, thermal stress analysis and the dynamic behaviour of high power RF structures. [MARC and SUPERFISH codes

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKeown, J.; Labrie, J.P.

1983-08-01

A general purpose finite element computer code called MARC is used to calculate the temperature distribution and dimensional changes in linear accelerator rf structures. Both steady state and transient behaviour are examined with the computer model. Combining results from MARC with the cavity evaluation computer code SUPERFISH, the static and dynamic behaviour of a structure under power is investigated. Structure cooling is studied to minimize loss in shunt impedance and frequency shifts during high power operation. Results are compared with an experimental test carried out on a cw 805 MHz on-axis coupled structure at an energy gradient of 1.8 MeV/m.more » The model has also been used to compare the performance of on-axis and coaxial structures and has guided the mechanical design of structures suitable for average gradients in excess of 2.0 MeV/m at 2.45 GHz.« less

Development and comparison of advanced reduced-basis methods for the transient structural analysis of unconstrained structures

NASA Technical Reports Server (NTRS)

Mcgowan, David M.; Bostic, Susan W.; Camarda, Charles J.

1993-01-01

The development of two advanced reduced-basis methods, the force derivative method and the Lanczos method, and two widely used modal methods, the mode displacement method and the mode acceleration method, for transient structural analysis of unconstrained structures is presented. Two example structural problems are studied: an undamped, unconstrained beam subject to a uniformly distributed load which varies as a sinusoidal function of time and an undamped high-speed civil transport aircraft subject to a normal wing tip load which varies as a sinusoidal function of time. These example problems are used to verify the methods and to compare the relative effectiveness of each of the four reduced-basis methods for performing transient structural analyses on unconstrained structures. The methods are verified with a solution obtained by integrating directly the full system of equations of motion, and they are compared using the number of basis vectors required to obtain a desired level of accuracy and the associated computational times as comparison criteria.

Investing the effectiveness of retention performance in a non-volatile floating gate memory device with a core-shell structure of CdSe nanoparticles

NASA Astrophysics Data System (ADS)

Lee, Dong-Hoon; Kim, Jung-Min; Lim, Ki-Tae; Cho, Hyeong Jun; Bang, Jin Ho; Kim, Yong-Sang

2016-03-01

In this paper, we empirically investigate the retention performance of organic non-volatile floating gate memory devices with CdSe nanoparticles (NPs) as charge trapping elements. Core-structured CdSe NPs or core-shell-structured ZnS/CdSe NPs were mixed in PMMA and their performance in pentacene based device was compared. The NPs and self-organized thin tunneling PMMA inside the devices exhibited hysteresis by trapping hole during capacitance-voltage characterization. Despite of core-structured NPs showing a larger memory window, the retention time was too short to be adopted by an industry. By contrast core-shell structured NPs showed an improved retention time of >10000 seconds than core-structure NCs. Based on these results and the energy band structure, we propose the retention mechanism of each NPs. This investigation of retention performance provides a comparative and systematic study of the charging/discharging behaviors of NPs based memory devices. [Figure not available: see fulltext.

Structured triglycerides were well tolerated and induced increased whole body fat oxidation compared with long-chain triglycerides in postoperative patients.

PubMed

Sandström, R; Hyltander, A; Körner, U; Lundholm, K

1995-01-01

It has been proposed, on the basis of animal experiments, that medium-chain triglycerides (MCT) may exert more favorable effects on whole body metabolism of injured animals than long-chain triglycerides (LCT). Therefore, the present study was designed to evaluate whether structured triglycerides are associated with increased whole body fat oxidation without promotion of ketogenesis in postoperative patients. A structured lipid emulsion (73403 Pharmacia, Sweden) containing medium- and long-chain fatty acids, esterified randomly to glycerol in a triglyceride structure, was used. Whole body fat oxidation was determined by indirect calorimetry in the postoperative period. Patients were randomized to receive structured lipids 1 day followed by LCT (Intralipid, Pharmacia) the next day or vice versa during 6 postoperative days. In part 1 of the study patients received fat at 1.0 g/kg per day in the presence of 80% of the basal requirement of nonprotein calories. In part 2 patients received fat at 1.5 g/kg per day in the presence of 120% of the nonprotein caloric requirement. Amino acids were always provided at 0.15 g N/kg per day. Structured lipids were not associated with any side effects, were rapidly cleared from the plasma compartment, and were rapidly oxidized without any significant hyperlipidemia or ketosis. Provision of structured lipids in the presence of excess of nonprotein calories (part 2) caused a significantly higher whole body fat oxidation (2.4 +/- 0.05 g/kg per day) compared with LCT provision (1.9 +/- 0.06 g/kg per day) (p < .0001) examined in the same patients. The results demonstrated for the first time in man that provision of structured triglycerides were associated with increased whole body fat oxidation in stressed postoperative patients, which is in line with the original metabolic and biochemical concept for structured triglycerides. The study provided evidence to support that structured lipids may represent a next generation of IV fat emulsions that may be clinically advantageous compared with conventional LCT emulsions in certain clinical conditions.

Structural efficiency studies of corrugated compression panels with curved caps and beaded webs

NASA Technical Reports Server (NTRS)

Davis, R. C.; Mills, C. T.; Prabhakaran, R.; Jackson, L. R.

1984-01-01

Curved cross-sectional elements are employed in structural concepts for minimum-mass compression panels. Corrugated panel concepts with curved caps and beaded webs are optimized by using a nonlinear mathematical programming procedure and a rigorous buckling analysis. These panel geometries are shown to have superior structural efficiencies compared with known concepts published in the literature. Fabrication of these efficient corrugation concepts became possible by advances made in the art of superplastically forming of metals. Results of the mass optimization studies of the concepts are presented as structural efficiency charts for axial compression.

Dance and music share gray matter structural correlates.

PubMed

Karpati, Falisha J; Giacosa, Chiara; Foster, Nicholas E V; Penhune, Virginia B; Hyde, Krista L

2017-02-15

Intensive practise of sensorimotor skills, such as music and dance, is associated with brain structural plasticity. While the neural correlates of music have been well-investigated, less is known about the neural correlates of dance. Additionally, the gray matter structural correlates of dance versus music training have not yet been directly compared. The objectives of the present study were to compare gray matter structure as measured by surface- and voxel-based morphometry between expert dancers, expert musicians and untrained controls, as well as to correlate gray matter structure with performance on dance- and music-related tasks. Dancers and musicians were found to have increased cortical thickness compared to controls in superior temporal regions. Gray matter structure in the superior temporal gyrus was also correlated with performance on dance imitation, rhythm synchronization and melody discrimination tasks. These results suggest that superior temporal regions are important in both dance- and music-related skills and may be affected similarly by both types of long-term intensive training. This work advances knowledge of the neural correlates of dance and music, as well as training-associated brain plasticity in general. Copyright © 2016 Elsevier B.V. All rights reserved.

Composition, structure and functional properties of protein concentrates and isolates produced from walnut (Juglans regia L.).

PubMed

Mao, Xiaoying; Hua, Yufei

2012-01-01

In this study, composition, structure and the functional properties of protein concentrate (WPC) and protein isolate (WPI) produced from defatted walnut flour (DFWF) were investigated. The results showed that the composition and structure of walnut protein concentrate (WPC) and walnut protein isolate (WPI) were significantly different. The molecular weight distribution of WPI was uniform and the protein composition of DFWF and WPC was complex with the protein aggregation. H(0) of WPC was significantly higher (p < 0.05) than those of DFWF and WPI, whilst WPI had a higher H(0) compared to DFWF. The secondary structure of WPI was similar to WPC. WPI showed big flaky plate like structures; whereas WPC appeared as a small flaky and more compact structure. The most functional properties of WPI were better than WPC. In comparing most functional properties of WPI and WPC with soybean protein concentrate and isolate, WPI and WPC showed higher fat absorption capacity (FAC). Emulsifying properties and foam properties of WPC and WPI in alkaline pH were comparable with that of soybean protein concentrate and isolate. Walnut protein concentrates and isolates can be considered as potential functional food ingredients.

@TOME-2: a new pipeline for comparative modeling of protein-ligand complexes.

PubMed

Pons, Jean-Luc; Labesse, Gilles

2009-07-01

@TOME 2.0 is new web pipeline dedicated to protein structure modeling and small ligand docking based on comparative analyses. @TOME 2.0 allows fold recognition, template selection, structural alignment editing, structure comparisons, 3D-model building and evaluation. These tasks are routinely used in sequence analyses for structure prediction. In our pipeline the necessary software is efficiently interconnected in an original manner to accelerate all the processes. Furthermore, we have also connected comparative docking of small ligands that is performed using protein-protein superposition. The input is a simple protein sequence in one-letter code with no comment. The resulting 3D model, protein-ligand complexes and structural alignments can be visualized through dedicated Web interfaces or can be downloaded for further studies. These original features will aid in the functional annotation of proteins and the selection of templates for molecular modeling and virtual screening. Several examples are described to highlight some of the new functionalities provided by this pipeline. The server and its documentation are freely available at http://abcis.cbs.cnrs.fr/AT2/

@TOME-2: a new pipeline for comparative modeling of protein–ligand complexes

PubMed Central

Pons, Jean-Luc; Labesse, Gilles

2009-01-01

@TOME 2.0 is new web pipeline dedicated to protein structure modeling and small ligand docking based on comparative analyses. @TOME 2.0 allows fold recognition, template selection, structural alignment editing, structure comparisons, 3D-model building and evaluation. These tasks are routinely used in sequence analyses for structure prediction. In our pipeline the necessary software is efficiently interconnected in an original manner to accelerate all the processes. Furthermore, we have also connected comparative docking of small ligands that is performed using protein–protein superposition. The input is a simple protein sequence in one-letter code with no comment. The resulting 3D model, protein–ligand complexes and structural alignments can be visualized through dedicated Web interfaces or can be downloaded for further studies. These original features will aid in the functional annotation of proteins and the selection of templates for molecular modeling and virtual screening. Several examples are described to highlight some of the new functionalities provided by this pipeline. The server and its documentation are freely available at http://abcis.cbs.cnrs.fr/AT2/ PMID:19443448

Sonic and Supersonic Jet Plumes

NASA Technical Reports Server (NTRS)

Venkatapathy, E.; Naughton, J. W.; Flethcher, D. G.; Edwards, Thomas A. (Technical Monitor)

1994-01-01

Study of sonic and supersonic jet plumes are relevant to understanding such phenomenon as jet-noise, plume signatures, and rocket base-heating and radiation. Jet plumes are simple to simulate and yet, have complex flow structures such as Mach disks, triple points, shear-layers, barrel shocks, shock- shear- layer interaction, etc. Experimental and computational simulation of sonic and supersonic jet plumes have been performed for under- and over-expanded, axisymmetric plume conditions. The computational simulation compare very well with the experimental observations of schlieren pictures. Experimental data such as temperature measurements with hot-wire probes are yet to be measured and will be compared with computed values. Extensive analysis of the computational simulations presents a clear picture of how the complex flow structure develops and the conditions under which self-similar flow structures evolve. From the computations, the plume structure can be further classified into many sub-groups. In the proposed paper, detail results from the experimental and computational simulations for single, axisymmetric, under- and over-expanded, sonic and supersonic plumes will be compared and the fluid dynamic aspects of flow structures will be discussed.

Structural dynamics of lipid bilayers using ultrafast electron crystallography

NASA Astrophysics Data System (ADS)

Chen, Songye; Seidel, Marco; Zewail, Ahmed

2007-03-01

The structures and dynamics of bilayers of crystalline fatty acids and phospholipids were studied using ultrafast electron crystallography (UEC). The systems investigated are arachidic (eicosanoic) acid and dimyristoyl phosphatidic acid (DMPA), deposited on a substrate by the Langmuir-Blodgett technique. The atomic structures under different preparation conditions were determined. The structural dynamics following a temperature jump induced by femtosecond laser on the substrates were obtained and compared to the equilibrium temperature dependence.

Electronic structure, elasticity, bonding features and mechanical behaviour of zinc intermetallics: A DFT study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fatima, Bushra, E-mail: bushrafatima25@gmail.com; Acharya, Nikita; Sanyal, Sankar P.

2016-05-06

The structural stability, electronic structure, elastic and mechanical properties of TiZn and ZrZn intermetallics have been studied using ab-initio full potential linearized augmented plane wave (FP-LAPW) method within generalized gradient approximation for exchange and correlation potentials. The various structural parameters, such as lattice constant (a{sub 0}), bulk modulus (B), and its pressure derivative (B’) are analysed and compared. The investigation of elastic constants affirm that both TiZn and ZrZn are elastically stable in CsCl (B{sub 2} phase) structure. The electronic structures have been analysed quantitatively from the band structure which reveals the metallic nature of these compounds. To better illustratemore » the nature of bonding and charge transfer, we have also studied the Fermi surfaces. The three well known criterion of ductility namely Pugh’s rule, Cauchy’s pressure and Frantsevich rule elucidate the ductile nature of these compounds.« less

Study of the bending vibration characteristic of phononic crystals beam-foundation structures by Timoshenko beam theory

NASA Astrophysics Data System (ADS)

Zhang, Yan; Ni, Zhi-Qiang; Jiang, Lin-Hua; Han, Lin; Kang, Xue-Wei

2015-07-01

Vibration problems wildly exist in beam-foundation structures. In this paper, finite periodic composites inspired by the concept of ideal phononic crystals (PCs), as well as Timoshenko beam theory (TBT), are proposed to the beam anchored on Winkler foundation. The bending vibration band structure of the PCs Timoshenko beam-foundation structure is derived from the modified transfer matrix method (MTMM) and Bloch's theorem. Then, the frequency response of the finite periodic composite Timoshenko beam-foundation structure by the finite element method (FEM) is performed to verify the above theoretical deduction. Study shows that the Timoshenko beam-foundation structure with periodic composites has wider attenuation zones compared with homogeneous ones. It is concluded that TBT is more available than Euler beam theory (EBT) in the study of the bending vibration characteristic of PCs beam-foundation structures with different length-to-height ratios.

A Comparison of Hyporheic Transport at a Cross-Vane Structure and Natural Riffle.

PubMed

Smidt, Samuel J; Cullin, Joseph A; Ward, Adam S; Robinson, Jesse; Zimmer, Margaret A; Lautz, Laura K; Endreny, Theodore A

2015-01-01

While restoring hyporheic flowpaths has been cited as a benefit to stream restoration structures, little documentation exists confirming that constructed restoration structures induce comparable hyporheic exchange to natural stream features. This study compares a stream restoration structure (cross-vane) to a natural feature (riffle) concurrently in the same stream reach using time-lapsed electrical resistivity (ER) tomography. Using this hydrogeophysical approach, we were able to quantify hyporheic extent and transport beneath the cross-vane structure and the riffle. We interpret from the geophysical data that the cross-vane and the natural riffle induced spatially and temporally unique hyporheic extent and transport, and the cross-vane created both spatially larger and temporally longer hyporheic flowpaths than the natural riffle. Tracer from the 4.67-h injection was detected along flowpaths for 4.6 h at the cross-vane and 4.2 h at the riffle. The spatial extent of the hyporheic zone at the cross-vane was 12% larger than that at the riffle. We compare ER results of this study to vertical fluxes calculated from temperature profiles and conclude significant differences in the interpretation of hyporheic transport from these different field techniques. Results of this study demonstrate a high degree of heterogeneity in transport metrics at both the cross-vane and the riffle and differences between the hyporheic flowpath networks at the two different features. Our results suggest that restoration structures may be capable of creating sufficient exchange flux and timescales of transport to achieve the same ecological functions as natural features, but engineering of the physical and biogeochemical environment may be necessary to realize these benefits. © 2014, National Ground Water Association.

A comparative study on managers', staffs' and clients' viewpoints about organizational and structural obstacles in family planning counseling in health-care centers in Isfahan in 2012.

PubMed

Taheri, Safoura; Ehsanpour, Soheila; Kohan, Shahnaz

2014-03-01

Organizational and structural obstacles are a group of major obstacles in achievement of appropriate family planning counseling. Detection of these obstacles from the viewpoint of managers, staffs and clients who are key members in health services providing system is a major step toward appropriate planning to modify or delete this group of obstacles. The present study was conducted with the goal of comparing managers', staffs' and clients' viewpoints about organizational and structural obstacles in family planning counseling in health-care centers in Isfahan in 2012. This is a cross-sectional one-step three-group comparative descriptive study conducted on 295 subjects including 59 managers, 110 staffs and 126 clients in medical health-care centers in Isfahan in 2012. Managers and the staffs were selected by census sampling and the clients were recruited through convenient random sampling. The date collection tool was a researcher made questionnaire, which was designed in two sections of fertility and personal characteristics and viewpoint measurement. Descriptive and inferential statistical test were used to analyze the data. The obtained results showed no significant difference between mean scores of viewpoints in three groups of managers, staffs and clients concerning organizational and structural obstacles in family planning counseling (P = 0.677). In addition, most of the managers, staffs and clients reported organizational and structural obstacles as the obstacles in the process of family planning in moderate level. The results showed the necessity of health services managers' planning to modify or delete organizational and structural obstacles especially the agreed obstacles from the viewpoint of managers, staffs and clients.

Structural approaches to knowledge exchange: comparing practices across five centres of excellence in public health.

PubMed

Van der Graaf, P; Francis, O; Doe, E; Barrett, E; O'Rorke, M; Docherty, G

2018-03-01

In 2008, five UKCRC Public Health Research Centres of Excellence were created to develop a coordinated approach to policy and practice engagement and knowledge exchange. The five Centres have developed their own models and practices for achieving these aims, which have not been compared in detail to date. We applied an extended version of Saner's model for the interface between science and policy to compare five case studies of knowledge exchanges, one from each centre. We compared these practices on three dimensions within our model (focus, function and type/scale) to identify barriers and facilitators for knowledge exchange. The case studies shared commonalities in their range of activities (type) but illustrated different ways of linking these activities (function). The Centres' approaches ranged from structural to more organic, and varied in the extent that they engaged internal audiences (focus). Each centre addressed policymakers at different geographical levels and scale. This article emphasizes the importance of linking a range of activities that engage policymakers at different levels, intensities and points in their decision-making processes to build relationships. Developing a structural approach to knowledge exchange activities in different contexts presents challenges of resource, implementation and evaluation.

Brain structure differences between Chinese and Caucasian cohorts: A comprehensive morphometry study.

PubMed

Tang, Yuchun; Zhao, Lu; Lou, Yunxia; Shi, Yonggang; Fang, Rui; Lin, Xiangtao; Liu, Shuwei; Toga, Arthur

2018-05-01

Numerous behavioral observations and brain function studies have demonstrated that neurological differences exist between East Asians and Westerners. However, the extent to which these factors relate to differences in brain structure is still not clear. As the basis of brain functions, the anatomical differences in brain structure play a primary and critical role in the origination of functional and behavior differences. To investigate the underlying differences in brain structure between the two cultural/ethnic groups, we conducted a comparative study on education-matched right-handed young male adults (age = 22-29 years) from two cohorts, Han Chinese (n = 45) and Caucasians (n = 45), using high-dimensional structural magnetic resonance imaging (MRI) data. Using two well-validated imaging analysis techniques, surface-based morphometry (SBM) and voxel-based morphometry (VBM), we performed a comprehensive vertex-wise morphometric analysis of the brain structures between Chinese and Caucasian cohorts. We identified consistent significant between-group differences in cortical thickness, volume, and surface area in the frontal, temporal, parietal, occipital, and insular lobes as well as the cingulate cortices. The SBM analyses revealed that compared with Caucasians, the Chinese population showed larger cortical structures in the temporal and cingulate regions, and smaller structural measures in the frontal and parietal cortices. The VBM data of the same sample was well-aligned with the SBM findings. Our findings systematically revealed comprehensive brain structural differences between young male Chinese and Caucasians, and provided new neuroanatomical insights to the behavioral and functional distinctions in the two cultural/ethnic populations. © 2018 Wiley Periodicals, Inc.

Power, Identity, and Organizational Structure as Reflected in Schools for Minority Groups: A Case Study of Jewish Schools in Paris, Brussels, and Geneva

ERIC Educational Resources Information Center

Gross, Zehavit

2006-01-01

This article compares the linkages between organizational structure, power relations, and group identities within the private schools operated by the francophone Jewish communities of Brussels, Paris, and Geneva. A school's organizational structure and balance of power reflect its identity and its conceptual world. That is, its organizational…

LaF3 insulators for MIS structures

NASA Technical Reports Server (NTRS)

Sher, A.; Tsuo, Y. H.; Moriarty, J. A.; Miller, W. E.; Crouch, R. K.; Seiber, B. A.

1979-01-01

Thin films of LaF3 deposited on Si or GaAs substrates have been observed to form blocking contacts with very high capacitances. This results in comparatively hysteresis-free and sharp C-V (capacitance-voltage) characteristics for MIS structures. Such structures have been used to study the interface states of GaAs with increased resolution and to construct improved photocapacitive infrared detectors.

Fathers' Involvement with Their Preschool-Age Children: How Fathers Spend Time with Their Children in Different Family Structures

ERIC Educational Resources Information Center

Halme, Nina; Astedt-Kurki, Paivi; Tarkka, Marja-Terttu

2009-01-01

The purpose of this study was to describe how fathers (n = 263) spent time with their preschool-age children and to compare it in different family structures. Data were gathered by structured questionnaires. The instrument included five categories of variables for the time spent: the quantity of time, physical activities, fathers' attitude towards…

Nuclear spectroscopy of doubly-even130,132Ba

NASA Astrophysics Data System (ADS)

Gupta, Anuradha; Gupta, Surbhi; Singh, Suram; Bharti, Arun

2018-05-01

A comparative study of some high-spin characteristic nuclear structure properties of doubly-even 130,132Ba nuclei has been made using two microscopic frameworks - CHFB and PSM. The yrast spectra, intrinsic quadrupole moment and deformation systematics of these nuclei have been successfully calculated. Further, the calculated data from both the frameworks is also compared with the available experimental data and a good agreement has been obtained. The present CHFB calculations describes very well the low spin structure of even-even 130,132Ba nuclei whereas PSM calculations provide a qualitative description of the high-spin band structure of doubly-even 130,132Ba nuclei.

Study on evaluation methods for Rayleigh wave dispersion characteristic

USGS Publications Warehouse

Shi, L.; Tao, X.; Kayen, R.; Shi, H.; Yan, S.

2005-01-01

The evaluation of Rayleigh wave dispersion characteristic is the key step for detecting S-wave velocity structure. By comparing the dispersion curves directly with the spectra analysis of surface waves (SASW) method, rather than comparing the S-wave velocity structure, the validity and precision of microtremor-array method (MAM) can be evaluated more objectively. The results from the China - US joint surface wave investigation in 26 sites in Tangshan, China, show that the MAM has the same precision with SASW method in 83% of the 26 sites. The MAM is valid for Rayleigh wave dispersion characteristic testing and has great application potentiality for site S-wave velocity structure detection.

Structural, spectroscopic and DFT study of 4-methoxybenzohydrazide Schiff bases. A new series of polyfunctional ligands.

PubMed

Ferraresi-Curotto, Verónica; Echeverría, Gustavo A; Piro, Oscar E; Pis-Diez, Reinaldo; González-Baró, Ana C

2015-02-25

Five Schiff bases obtained from condensation of 4-methoxybenzohydrazide with related aldehydes, namely o-vanillin, vanillin, 5-bromovanillin, 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde were prepared. A detailed structural and spectroscopic study is reported. The crystal structures of four members of the family were determined and compared with one another. The hydrazones obtained from 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde resulted to be isomorphic to each other. The solid-state structures are stabilized by intra-molecular O-H⋯N interactions in salicylaldehyde derivatives between the O-H moiety from the aldehyde and the hydrazone nitrogen atom. All crystals are further stabilized by inter-molecular H-bonds mediated by the crystallization water molecule. A comparative analysis between experimental and theoretical results is presented. The conformational space was searched and geometries were optimized both in gas phase and including solvent effects. The structure is predicted for the compound for which the crystal structure was not determined. Infrared and electronic spectra were measured and assigned with the help of data obtained from computational methods based on the Density Functional Theory. Copyright © 2014 Elsevier B.V. All rights reserved.

Structure change of β-hairpin induced by turn optimization: an enhanced sampling molecular dynamics simulation study.

PubMed

Shao, Qiang; Yang, Lijiang; Gao, Yi Qin

2011-12-21

Our previous study showed that for the tested polypeptides which have similar β-hairpin structures but different sequences, their folding free energy pathways are dominantly determined by the turn conformational propensity. In this study, we study how the turn conformational propensity affects the structure of hairpins. The folding of two mutants of GB1p peptide (GB1m2 and GB1m3), which have the optimized turn sequence ((6)DDATK(11)T → (6)NPATG(11)K) with native structures unsolved, were simulated using integrated tempering sampling molecular dynamics simulations and the predicted stable structures were compared to wild-type GB1p. It was observed that the turn optimization of GB1p generates a more favored 5-residue type I(') turn in addition to the 6-residue type I turn in wild-type GB1p. As a result two distinctly different hairpin structures are formed corresponding to the "misfolded" (M) and the "folded" (F) states. M state is a one-residue-shifted asymmetric β-hairpin structure whereas F state has the similar symmetric hairpin structure as wild-type GB1p. The formation of the favored type I(') turn has a small free energy barrier and leads to the shifted β-hairpin structure, following the modified "zipping" model. The presence of disfavored type I turn structure makes the folding of a β-hairpin consistent with the "hydrophobic-core-centric" model. On the other hand, the folding simulations on other two GB1p mutants (GB1r1 and GBr2), which have the position of the hydrophobic core cluster further away from the turn compared to wild-type GB1p, showed that moving the hydrophobic core cluster away from the turn region destabilizes but does not change the hairpin structure. Therefore, the present study showed that the turn conformational propensity is a key factor in affecting not only the folding pathways but also the stable structure of β-hairpins, and the turn conformational change induced by the turn optimization leads to significant changes of β-hairpin structure.

RNACompress: Grammar-based compression and informational complexity measurement of RNA secondary structure.

PubMed

Liu, Qi; Yang, Yu; Chen, Chun; Bu, Jiajun; Zhang, Yin; Ye, Xiuzi

2008-03-31

With the rapid emergence of RNA databases and newly identified non-coding RNAs, an efficient compression algorithm for RNA sequence and structural information is needed for the storage and analysis of such data. Although several algorithms for compressing DNA sequences have been proposed, none of them are suitable for the compression of RNA sequences with their secondary structures simultaneously. This kind of compression not only facilitates the maintenance of RNA data, but also supplies a novel way to measure the informational complexity of RNA structural data, raising the possibility of studying the relationship between the functional activities of RNA structures and their complexities, as well as various structural properties of RNA based on compression. RNACompress employs an efficient grammar-based model to compress RNA sequences and their secondary structures. The main goals of this algorithm are two fold: (1) present a robust and effective way for RNA structural data compression; (2) design a suitable model to represent RNA secondary structure as well as derive the informational complexity of the structural data based on compression. Our extensive tests have shown that RNACompress achieves a universally better compression ratio compared with other sequence-specific or common text-specific compression algorithms, such as Gencompress, winrar and gzip. Moreover, a test of the activities of distinct GTP-binding RNAs (aptamers) compared with their structural complexity shows that our defined informational complexity can be used to describe how complexity varies with activity. These results lead to an objective means of comparing the functional properties of heteropolymers from the information perspective. A universal algorithm for the compression of RNA secondary structure as well as the evaluation of its informational complexity is discussed in this paper. We have developed RNACompress, as a useful tool for academic users. Extensive tests have shown that RNACompress is a universally efficient algorithm for the compression of RNA sequences with their secondary structures. RNACompress also serves as a good measurement of the informational complexity of RNA secondary structure, which can be used to study the functional activities of RNA molecules.

RNACompress: Grammar-based compression and informational complexity measurement of RNA secondary structure

PubMed Central

Liu, Qi; Yang, Yu; Chen, Chun; Bu, Jiajun; Zhang, Yin; Ye, Xiuzi

2008-01-01

Background With the rapid emergence of RNA databases and newly identified non-coding RNAs, an efficient compression algorithm for RNA sequence and structural information is needed for the storage and analysis of such data. Although several algorithms for compressing DNA sequences have been proposed, none of them are suitable for the compression of RNA sequences with their secondary structures simultaneously. This kind of compression not only facilitates the maintenance of RNA data, but also supplies a novel way to measure the informational complexity of RNA structural data, raising the possibility of studying the relationship between the functional activities of RNA structures and their complexities, as well as various structural properties of RNA based on compression. Results RNACompress employs an efficient grammar-based model to compress RNA sequences and their secondary structures. The main goals of this algorithm are two fold: (1) present a robust and effective way for RNA structural data compression; (2) design a suitable model to represent RNA secondary structure as well as derive the informational complexity of the structural data based on compression. Our extensive tests have shown that RNACompress achieves a universally better compression ratio compared with other sequence-specific or common text-specific compression algorithms, such as Gencompress, winrar and gzip. Moreover, a test of the activities of distinct GTP-binding RNAs (aptamers) compared with their structural complexity shows that our defined informational complexity can be used to describe how complexity varies with activity. These results lead to an objective means of comparing the functional properties of heteropolymers from the information perspective. Conclusion A universal algorithm for the compression of RNA secondary structure as well as the evaluation of its informational complexity is discussed in this paper. We have developed RNACompress, as a useful tool for academic users. Extensive tests have shown that RNACompress is a universally efficient algorithm for the compression of RNA sequences with their secondary structures. RNACompress also serves as a good measurement of the informational complexity of RNA secondary structure, which can be used to study the functional activities of RNA molecules. PMID:18373878

Analysis and sizing of Mars aerobrake structure

NASA Technical Reports Server (NTRS)

Raju, I. S.; Craft, W. J.

1993-01-01

A cone-sphere aeroshell structure for aerobraking into Martian atmosphere is studied. Using this structural configuration, a space frame load-bearing structure is proposed. To generate this structure efficiently and to perform a variety of studies of several configurations, a mesh generator that utilizes only a few configurational parameters is developed. A finite element analysis program that analyzes space frame structures was developed. A sizing algorithm that arrives at a minimum mass configuration was developed and integrated into the finite element analysis program. A typical 135-ft-diam aerobrake configuration was analyzed and sized. The minimum mass obtained in this study using high modulus graphite/epoxy composite material members is compared with the masses obtained from two other aerobrake structures using lightweight erectable tetrahedral truss and part-spherical truss configurations. Excellent agreement for the minimum mass was obtained with the three different aerobrake structures. Also, the minimum mass using the present structure was obtained when the supports were not at the base but at about 75 percent of the base diameter.

Structural and conformational analysis of pentostatin (2'-deoxycoformycin), a potent inhibitor of adenosine deaminase.

PubMed

Cox, M B; Arjunan, P; Arora, S K

1990-08-01

X-ray, NMR and molecular mechanics studies on pentostatin (C11H16N4O4), a potent inhibitor of the enzyme adenosine deaminase, have been carried out to study the structure and conformation. The crystals belong to the monoclinic space group P21 with the cell dimensions of a = 4.960(1), b = 10.746(3), c = 11.279(4)A, beta = 101.18(2) degrees and Z = 2. The structure was solved by direct methods and difference Fourier methods and refined to an R value of 0.047 for 997 reflections. The trihydrodiazepine ring is nonplanar and adopts a distorted sofa conformation with C(7) deviated from the mean plane by 0.66A. The deoxyribose ring adopts a C3'-endo conformation, different from coformycin where the sugar has a C2'-endo conformation. The observed glycosidic torsion angle (chi = -119.5 degrees) is in the anti range. The conformation about the C(4')-C(5') bond is gauche+. The conformation of the molecule is compared with that of coformycin and 2-azacoformycin. 1 and 2D NMR studies have been carried out and the dihedral angles obtained from coupling constants have been compared with those obtained from the crystal structure. The conformation of deoxyribose in solution is approximately 70% S and 30% N. Molecular mechanics studies were performed to obtain the energy minimized conformation, which is compared with X-ray and NMR results.

How Much Structuring Is Beneficial with Regard to Examination Scores? A Prospective Study of Three Forms of Active Learning

ERIC Educational Resources Information Center

Reinhardt, Claus H.; Rosen, Evelyne N.

2012-01-01

Many studies have demonstrated a superiority of active learning forms compared with traditional lecture. However, there is still debate as to what degree structuring is necessary with regard to high exam outcomes. Seventy-five students from a premedical school were randomly attributed to an active lecture group, a cooperative group, or a…

Analysis and trade-off studies of large lightweight mirror structures. [large space telescope

NASA Technical Reports Server (NTRS)

Soosaar, K.; Grin, R.; Ayer, F.

1975-01-01

A candidate mirror, hexagonally lightweighted, is analyzed under various loadings using as complete a procedure as possible. Successive simplifications are introduced and compared to an original analysis. A model which is a reasonable compromise between accuracy and cost is found and is used for making trade-off studies of the various structural parameters of the lightweighted mirror.

A Study of the Effects of Competitive Team-Based Learning and Structured Academic Controversy on the Language Proficiency of Iranian EFL College Seniors

ERIC Educational Resources Information Center

Hosseini, Seyed Mohammad Hassan

2012-01-01

This paper presents reports on an experimental study which intended to look into and compare the possible effects of this researcher's instructional innovation, Competitive Team-Based Learning (CTBL), with Structured Academic Controversy (SAC) -- the most popular method of Cooperative Learning (CL) -- on language proficiency of Iranian EFL college…

Comparing Multiple Solutions in the Structured Problem Solving: Deconstructing Japanese Lessons from Learner's Perspective

ERIC Educational Resources Information Center

Hino, Keiko

2015-01-01

The purpose of this study is to enhance our understanding of how students listen and attend to multiple solutions proposed by their classmates during the activity of comparison. This study examines ten consecutive lessons in each of the two eighth-grade classrooms in Tokyo that are organized in the style of "structured problem solving".…

Special Study: Inadequate Structural Assembly of Schoolbus Bodies. The Accidents at Decatur and Huntsville, Alabama.

ERIC Educational Resources Information Center

National Transportation Safety Board (DOT), Washington, DC. Bureau of Surface Transportation Safety.

This study reviews some examples of injuries received in two school bus accidents; explains how the design of joints and fastenings in the buses was involved in the injuries and in the structural strength of schoolbuses; and compares schoolbus construction with construction of other types of buses that employ more efficient and complete…

Discovery of riblets in a bird beak (Rynchops) for low fluid drag

PubMed Central

2016-01-01

Riblet structures found on fast-swimming shark scales, such as those found on a mako shark, have been shown to reduce fluid drag. In previous experimental and modelling studies, riblets have been shown to provide drag reduction by lifting vortices formed in turbulent flow, decreasing overall shear stresses. Skimmer birds (Rynchops) are the only birds to catch fish in flight by flying just above the water surface with a submerged beak to fish for food. Because they need to quickly catch prey, reducing drag on their beak is advantageous. For the first time, riblet structures found on the beak of the skimmer bird have been studied experimentally and computationally for low fluid drag properties. In this study, skimmer replicas were studied for drag reduction through pressure drop in closed-channel, turbulent water flow. Pressure drop measurements are compared for black and yellow skimmer beaks in two configurations, and mako shark skin. In addition, two configurations of skimmer beak were modelled to compare drag properties and vortex structures. Results are discussed, and a conceptual model is presented to explain a possible drag reduction mechanism in skimmers. This article is part of the themed issue ‘Bioinspired hierarchically structured surfaces for green science’. PMID:27354734

The distribution of cigarette prices under different tax structures: findings from the International Tobacco Control Policy Evaluation (ITC) Project

PubMed Central

Shang, Ce; Chaloupka, Frank J; Zahra, Nahleen; Fong, Geoffrey T

2013-01-01

Background The distribution of cigarette prices has rarely been studied and compared under different tax structures. Descriptive evidence on price distributions by countries can shed light on opportunities for tax avoidance and brand switching under different tobacco tax structures, which could impact the effectiveness of increased taxation in reducing smoking. Objective This paper aims to describe the distribution of cigarette prices by countries and to compare these distributions based on the tobacco tax structure in these countries. Methods We employed data for 16 countries taken from the International Tobacco Control Policy Evaluation Project to construct survey-derived cigarette prices for each country. Self-reported prices were weighted by cigarette consumption and described using a comprehensive set of statistics. We then compared these statistics for cigarette prices under different tax structures. In particular, countries of similar income levels and countries that impose similar total excise taxes using different tax structures were paired and compared in mean and variance using a two-sample comparison test. Findings Our investigation illustrates that, compared with specific uniform taxation, other tax structures, such as ad valorem uniform taxation, mixed (a tax system using ad valorem and specific taxes) uniform taxation, and tiered tax structures of specific, ad valorem and mixed taxation tend to have price distributions with greater variability. Countries that rely heavily on ad valorem and tiered taxes also tend to have greater price variability around the median. Among mixed taxation systems, countries that rely more heavily on the ad valorem component tend to have greater price variability than countries that rely more heavily on the specific component. In countries with tiered tax systems, cigarette prices are skewed more towards lower prices than are prices under uniform tax systems. The analyses presented here demonstrate that more opportunities exist for tax avoidance and brand switching when the tax structure departs from a uniform specific tax. PMID:23792324

The distribution of cigarette prices under different tax structures: findings from the International Tobacco Control Policy Evaluation (ITC) Project.

PubMed

Shang, Ce; Chaloupka, Frank J; Zahra, Nahleen; Fong, Geoffrey T

2014-03-01

The distribution of cigarette prices has rarely been studied and compared under different tax structures. Descriptive evidence on price distributions by countries can shed light on opportunities for tax avoidance and brand switching under different tobacco tax structures, which could impact the effectiveness of increased taxation in reducing smoking. This paper aims to describe the distribution of cigarette prices by countries and to compare these distributions based on the tobacco tax structure in these countries. We employed data for 16 countries taken from the International Tobacco Control Policy Evaluation Project to construct survey-derived cigarette prices for each country. Self-reported prices were weighted by cigarette consumption and described using a comprehensive set of statistics. We then compared these statistics for cigarette prices under different tax structures. In particular, countries of similar income levels and countries that impose similar total excise taxes using different tax structures were paired and compared in mean and variance using a two-sample comparison test. Our investigation illustrates that, compared with specific uniform taxation, other tax structures, such as ad valorem uniform taxation, mixed (a tax system using ad valorem and specific taxes) uniform taxation, and tiered tax structures of specific, ad valorem and mixed taxation tend to have price distributions with greater variability. Countries that rely heavily on ad valorem and tiered taxes also tend to have greater price variability around the median. Among mixed taxation systems, countries that rely more heavily on the ad valorem component tend to have greater price variability than countries that rely more heavily on the specific component. In countries with tiered tax systems, cigarette prices are skewed more towards lower prices than are prices under uniform tax systems. The analyses presented here demonstrate that more opportunities exist for tax avoidance and brand switching when the tax structure departs from a uniform specific tax.

Three-dimensional volume rendering of the ankle based on magnetic resonance images enables the generation of images comparable to real anatomy.

PubMed

Anastasi, Giuseppe; Cutroneo, Giuseppina; Bruschetta, Daniele; Trimarchi, Fabio; Ielitro, Giuseppe; Cammaroto, Simona; Duca, Antonio; Bramanti, Placido; Favaloro, Angelo; Vaccarino, Gianluigi; Milardi, Demetrio

2009-11-01

We have applied high-quality medical imaging techniques to study the structure of the human ankle. Direct volume rendering, using specific algorithms, transforms conventional two-dimensional (2D) magnetic resonance image (MRI) series into 3D volume datasets. This tool allows high-definition visualization of single or multiple structures for diagnostic, research, and teaching purposes. No other image reformatting technique so accurately highlights each anatomic relationship and preserves soft tissue definition. Here, we used this method to study the structure of the human ankle to analyze tendon-bone-muscle relationships. We compared ankle MRI and computerized tomography (CT) images from 17 healthy volunteers, aged 18-30 years (mean 23 years). An additional subject had a partial rupture of the Achilles tendon. The MRI images demonstrated superiority in overall quality of detail compared to the CT images. The MRI series accurately rendered soft tissue and bone in simultaneous image acquisition, whereas CT required several window-reformatting algorithms, with loss of image data quality. We obtained high-quality digital images of the human ankle that were sufficiently accurate for surgical and clinical intervention planning, as well as for teaching human anatomy. Our approach demonstrates that complex anatomical structures such as the ankle, which is rich in articular facets and ligaments, can be easily studied non-invasively using MRI data.

Three-dimensional volume rendering of the ankle based on magnetic resonance images enables the generation of images comparable to real anatomy

PubMed Central

Anastasi, Giuseppe; Cutroneo, Giuseppina; Bruschetta, Daniele; Trimarchi, Fabio; Ielitro, Giuseppe; Cammaroto, Simona; Duca, Antonio; Bramanti, Placido; Favaloro, Angelo; Vaccarino, Gianluigi; Milardi, Demetrio

2009-01-01

We have applied high-quality medical imaging techniques to study the structure of the human ankle. Direct volume rendering, using specific algorithms, transforms conventional two-dimensional (2D) magnetic resonance image (MRI) series into 3D volume datasets. This tool allows high-definition visualization of single or multiple structures for diagnostic, research, and teaching purposes. No other image reformatting technique so accurately highlights each anatomic relationship and preserves soft tissue definition. Here, we used this method to study the structure of the human ankle to analyze tendon–bone–muscle relationships. We compared ankle MRI and computerized tomography (CT) images from 17 healthy volunteers, aged 18–30 years (mean 23 years). An additional subject had a partial rupture of the Achilles tendon. The MRI images demonstrated superiority in overall quality of detail compared to the CT images. The MRI series accurately rendered soft tissue and bone in simultaneous image acquisition, whereas CT required several window-reformatting algorithms, with loss of image data quality. We obtained high-quality digital images of the human ankle that were sufficiently accurate for surgical and clinical intervention planning, as well as for teaching human anatomy. Our approach demonstrates that complex anatomical structures such as the ankle, which is rich in articular facets and ligaments, can be easily studied non-invasively using MRI data. PMID:19678857

Childhood Music Training Induces Change in Micro and Macroscopic Brain Structure: Results from a Longitudinal Study.

PubMed

Habibi, Assal; Damasio, Antonio; Ilari, Beatriz; Veiga, Ryan; Joshi, Anand A; Leahy, Richard M; Haldar, Justin P; Varadarajan, Divya; Bhushan, Chitresh; Damasio, Hanna

2017-11-08

Several studies comparing adult musicians and nonmusicians have shown that music training is associated with structural brain differences. It is not been established, however, whether such differences result from pre-existing biological traits, lengthy musical training, or an interaction of the two factors, or if comparable changes can be found in children undergoing music training. As part of an ongoing longitudinal study, we investigated the effects of music training on the developmental trajectory of children's brain structure, over two years, beginning at age 6. We compared these children with children of the same socio-economic background but either involved in sports training or not involved in any systematic after school training. We established at the onset that there were no pre-existing structural differences among the groups. Two years later we observed that children in the music group showed (1) a different rate of cortical thickness maturation between the right and left posterior superior temporal gyrus, and (2) higher fractional anisotropy in the corpus callosum, specifically in the crossing pathways connecting superior frontal, sensory, and motor segments. We conclude that music training induces macro and microstructural brain changes in school-age children, and that those changes are not attributable to pre-existing biological traits. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Structural covariance and cortical reorganisation in schizophrenia: a MRI-based morphometric study.

PubMed

Palaniyappan, Lena; Hodgson, Olha; Balain, Vijender; Iwabuchi, Sarina; Gowland, Penny; Liddle, Peter

2018-05-06

In patients with schizophrenia, distributed abnormalities are observed in grey matter volume. A recent hypothesis posits that these distributed changes are indicative of a plastic reorganisation process occurring in response to a functional defect in neuronal information transmission. We investigated the structural covariance across various brain regions in early-stage schizophrenia to determine if indeed the observed patterns of volumetric loss conform to a coordinated pattern of structural reorganisation. Structural magnetic resonance imaging scans were obtained from 40 healthy adults and 41 age, gender and parental socioeconomic status matched patients with schizophrenia. Volumes of grey matter tissue were estimated at the regional level across 90 atlas-based parcellations. Group-level structural covariance was studied using a graph theoretical framework. Patients had distributed reduction in grey matter volume, with high degree of localised covariance (clustering) compared with controls. Patients with schizophrenia had reduced centrality of anterior cingulate and insula but increased centrality of the fusiform cortex, compared with controls. Simulating targeted removal of highly central nodes resulted in significant loss of the overall covariance patterns in patients compared with controls. Regional volumetric deficits in schizophrenia are not a result of random, mutually independent processes. Our observations support the occurrence of a spatially interconnected reorganisation with the systematic de-escalation of conventional 'hub' regions. This raises the question of whether the morphological architecture in schizophrenia is primed for compensatory functions, albeit with a high risk of inefficiency.

Comparison of the Diagnostic Image Quality of the Canine Maxillary Dentoalveolar Structures Obtained by Cone Beam Computed Tomography and 64-Multidetector Row Computed Tomography.

PubMed

Soukup, Jason W; Drees, Randi; Koenig, Lisa J; Snyder, Christopher J; Hetzel, Scott; Miles, Chanda R; Schwarz, Tobias

2015-01-01

The objective of this blinded study was to validate the use of cone beam computed tomography (C) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methylmethacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxillary segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT.

Comparison of the Diagnostic Image Quality of the Canine Maxillary Dentoalveolar Structures Obtained by Cone Beam Computed Tomography and 64-Multidetector Row Computed Tomography

PubMed Central

Soukup, Jason W.; Drees, Randi; Koenig, Lisa J.; Snyder, Christopher J.; Hetzel, Scott; Miles, Chanda R.; Schwarz, Tobias

2016-01-01

Summary The objective of this blinded study was to validate the use of cone beam computed tomography (CT) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT. Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methyl methacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxilla segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored. In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting, cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT. PMID:26415384

A systematic review of structured versus non-structured breastfeeding programmes to support the initiation and duration of exclusive breastfeeding in acute and primary healthcare settings.

PubMed

Beake, Sarah; Pellowe, Carol; Dykes, Fiona; Schmied, Virginia; Bick, Debra

2011-01-01

Background: Breastfeeding has many important health benefits for the woman and her baby. Despite evidence of benefit from a large number of well conducted studies, breastfeeding uptake and the duration of exclusive breastfeeding remain low in many countries. In order to improve breastfeeding rates, policy and guidelines at global, individual country level and in local healthcare settings have recommended that structured programmes to support breastfeeding should be introduced. The objective of this review was to consider the evidence of outcomes of structured compared with non-structured breastfeeding programmes in acute maternity care settings to support initiation and duration of exclusive breastfeeding. The definition of structured programme used included a multi-faceted or single intervention approach to support breastfeeding; definition of non-structured included support offered within standard care. The review considered quantitative and qualitative studies which addressed outcomes following the introduction of a structured programme in acute healthcare settings to support breastfeeding compared with no programme. The primary outcomes of interest were uptake of breastfeeding and duration of exclusive breastfeeding (only breast milk, including milk expressed). Studies which only considered community based interventions were not included. A search of the literature published between 1992 and 2010 was conducted, which followed a four step process. After a limited search of MEDLINE and CINAHL to identify key words contained in the title or abstract and index terms to describe relevant interventions, a second extensive search was undertaken using identified key words and index terms. The third step included a search of reference lists and bibliographies of relevant articles and the fourth step included a search of grey and unpublished literature and national databasesMethodological quality: Methodological quality was assessed using checklists developed by the Joanna Briggs Institute. Two independent reviewers conducted critical appraisal and data extraction. Twenty-six articles were included; one randomised controlled trial, two non randomised trials, one cross-sectional study, five systematic reviews, 15 cohort studies and two descriptive studies. Due to the poor quality of evidence presented and clinical and methodological heterogeneity of study designs, including definitions of breastfeeding and duration of follow-up, it was not possible to combine studies or individual outcomes in meta-analyses, therefore findings are presented in a narrative form.In most studies the structured programme of interest reflected some or all of the Baby Friendly Hospital Initiative 'Ten Steps'. Most studies found a statistically significant improvement in initiation of breastfeeding following introduction of a structured breastfeeding programme, although effect sizes varied widely.The impact of introducing a structured programme on the duration of exclusive breastfeeding and duration of any breastfeeding was also evident, although not all studies found statistically significant differences. At hospital discharge or within the first week post-birth, implementation of a structured programme appeared to increase duration of exclusive breastfeeding and the duration of any breastfeeding compared with usual care. After hospital discharge and up to six months post-birth, use of structured programmes also appeared to support continued duration of exclusive and any breastfeeding although differences in outcomes were not reported across all included studies. At six months, three of five studies which included data on longer-term outcomes showed women were statistically significantly more likely to be exclusively breastfeeding. Only one of these studies compared outcomes following implementation of BFHI. Despite the poor overall quality of studies, structured programmes, regardless of content, compared with standard care appear to influence the uptake and duration of exclusive breastfeeding and any breastfeeding. In healthcare settings with low breastfeeding uptake and duration rates, structured programmes may have a greater benefit. In countries where breastfeeding uptake is already high, the benefit is less apparent. The extent to which structured programmes in different maternity acute care settings have a significant effect on the duration of exclusive breastfeeding at six months is less clear. Most of the recommendations of this review were based on observational studies and retrospective data collection. Few studies controlled for any potential confounding factors and the impact of bias has to be considered. Acute maternity care settings should implement structured programmes to support breastfeeding as part of routine maternity care. Programmes can replicate an existing programme, such as the BFHI, in full or in part, or be specifically developed to support implementation of evidence to reflect the needs and demands of the local healthcare organisation. In healthcare settings which have a high uptake of breastfeeding, resources may be better directed at improving support for duration of exclusive breastfeeding in the community. Further high quality RCTs are needed which address the impact of introduction of structured programmes on women's experiences of infant feeding, on the role of the relevant healthcare professionals and on short and longer-term health outcomes. Prospective data capture to inform economic analyses should also be undertaken. Trial interventions need to be well defined and implementation processes described to inform reproducibility across different locations and different country settings. Research is also needed to address the issue of which elements of a structured programme are likely to lead to the most clinical and cost effective use of healthcare resources and to address how sustainable these interventions are in health systems facing increased economic pressures.

Larger Gray Matter Volume in the Basal Ganglia of Heavy Cannabis Users Detected by Voxel-Based Morphometry and Subcortical Volumetric Analysis.

PubMed

Moreno-Alcázar, Ana; Gonzalvo, Begoña; Canales-Rodríguez, Erick J; Blanco, Laura; Bachiller, Diana; Romaguera, Anna; Monté-Rubio, Gemma C; Roncero, Carlos; McKenna, Peter J; Pomarol-Clotet, Edith

2018-01-01

Background: Structural imaging studies of cannabis users have found evidence of both cortical and subcortical volume reductions, especially in cannabinoid receptor-rich regions such as the hippocampus and amygdala. However, the findings have not been consistent. In the present study, we examined a sample of adult heavy cannabis users without other substance abuse to determine whether long-term use is associated with brain structural changes, especially in the subcortical regions. Method: We compared the gray matter volume of 14 long-term, heavy cannabis users with non-using controls. To provide robust findings, we conducted two separate studies using two different MRI techniques. Each study used the same sample of cannabis users and a different control group, respectively. Both control groups were independent of each other. First, whole-brain voxel-based morphometry (VBM) was used to compare the cannabis users against 28 matched controls (HC1 group). Second, a volumetric analysis of subcortical regions was performed to assess differences between the cannabis users and a sample of 100 matched controls (HC2 group) obtained from a local database of healthy volunteers. Results: The VBM study revealed that, compared to the control group HC1, the cannabis users did not show cortical differences nor smaller volume in any subcortical structure but showed a cluster ( p < 0.001) of larger GM volume in the basal ganglia, involving the caudate, putamen, pallidum, and nucleus accumbens, bilaterally. The subcortical volumetric analysis revealed that, compared to the control group HC2, the cannabis users showed significantly larger volumes in the putamen ( p = 0.001) and pallidum ( p = 0.0015). Subtle trends, only significant at the uncorrected level, were also found in the caudate ( p = 0.05) and nucleus accumbens ( p = 0.047). Conclusions: This study does not support previous findings of hippocampal and/or amygdala structural changes in long-term, heavy cannabis users. It does, however, provide evidence of basal ganglia volume increases.

Impact of variational assimilation using multivariate background error covariances on the simulation of monsoon depressions over India

NASA Astrophysics Data System (ADS)

Dhanya, M.; Chandrasekar, A.

2016-02-01

The background error covariance structure influences a variational data assimilation system immensely. The simulation of a weather phenomenon like monsoon depression can hence be influenced by the background correlation information used in the analysis formulation. The Weather Research and Forecasting Model Data assimilation (WRFDA) system includes an option for formulating multivariate background correlations for its three-dimensional variational (3DVar) system (cv6 option). The impact of using such a formulation in the simulation of three monsoon depressions over India is investigated in this study. Analysis and forecast fields generated using this option are compared with those obtained using the default formulation for regional background error correlations (cv5) in WRFDA and with a base run without any assimilation. The model rainfall forecasts are compared with rainfall observations from the Tropical Rainfall Measurement Mission (TRMM) and the other model forecast fields are compared with a high-resolution analysis as well as with European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim reanalysis. The results of the study indicate that inclusion of additional correlation information in background error statistics has a moderate impact on the vertical profiles of relative humidity, moisture convergence, horizontal divergence and the temperature structure at the depression centre at the analysis time of the cv5/cv6 sensitivity experiments. Moderate improvements are seen in two of the three depressions investigated in this study. An improved thermodynamic and moisture structure at the initial time is expected to provide for improved rainfall simulation. The results of the study indicate that the skill scores of accumulated rainfall are somewhat better for the cv6 option as compared to the cv5 option for at least two of the three depression cases studied, especially at the higher threshold levels. Considering the importance of utilising improved flow-dependent correlation structures for efficient data assimilation, the need for more studies on the impact of background error covariances is obvious.

Investigating the performance of catalyst layer micro-structures with different platinum loadings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khakaz-Baboli, Moben; Harvey, David; Pharoah, Jon

In this study a four-phase micro-structure of a PEFC catalyst layer was reconstructed by randomly placing overlapping spheres for each solid catalyst phase. The micro-structure was mirrored to make a micro-structure. A body-fit computational mesh was produced for the reconstructed micro-structure in OpenFOAM. Associated conservation equations were solved within all the phases with electrochemical reaction as the boundary condition at the interface between ionomer and platinum phases. The study is focused on the platinum loading of CL. The polarization curves of the micro-structure performance have been compared for different platinum loadings. This paper gives increased insight into the relatively greatermore » losses at decreased platinum loadings.« less

Composite Structure Optimization with Genetic Algorithm

NASA Astrophysics Data System (ADS)

Deslandes, Olivier

2014-06-01

In the frame of optimization studies in CNES launcher directorate structure, thermic and material department, the need of an optimization tool based on metaheuristic and finite element models for composite structural dimensioning was underlined.Indeed, composite structures need complex optimization methodologies in order to be really compared to metallic structures with regard to mass, static strength and stiffness constraints (metallic structures using optimization methods better known).After some bibliography research, the use of a genetic algorithm coupled with design of experiment to generate the initial population was chosen. Academic functions were used to validate the optimization process and then it was applied to an industrial study aiming to optimize an interstage skirt with regard to its mass, stiffness and stability (global buckling).

Analytical investigation of a three-dimensional FRP-retrofitted reinforced concrete structure's behaviour under earthquake load effect in ANSYS program

NASA Astrophysics Data System (ADS)

Altun, F.; Birdal, F.

2012-12-01

In this study, a 1:3 scaled, three-storey, FRP (Fiber Reinforced Polymer) retrofitted reinforced concrete model structure whose behaviour and crack development were identified experimentally in the laboratory was investigated analytically. Determination of structural behaviour under earthquake load is only possible in a laboratory environment with a specific scale, as carrying out structural experiments is difficult due to the evaluation of increased parameter numbers and because it requires an expensive laboratory setup. In an analytical study, structure was modelled using ANSYS Finite Element Package Program (2007), and its behaviour and crack development were revealed. When experimental difficulties are taken into consideration, analytical investigation of structure behaviour is more economic and much faster. At the end of the study, experimental results of structural behaviour and crack development were compared with analytical data. It was concluded that in a model structure retrofitted with FRP, the behaviour and cracking model can be determined without testing by determining the reasons for the points where analytical results are not converged with experimental data. Better understanding of structural behaviour is analytically enabled with the study.

Enhancement of Performance and Mechanism Studies of All-Solution Processed Small-Molecule based Solar Cells with an Inverted Structure.

PubMed

Long, Guankui; Wu, Bo; Yang, Xuan; Kan, Bin; Zhou, Ye-Cheng; Chen, Li-Chuan; Wan, Xiangjian; Zhang, Hao-Li; Sum, Tze Chien; Chen, Yongsheng

2015-09-30

Both solution-processed polymers and small molecule based solar cells have achieved PCEs over 9% with the conventional device structure. However, for the practical applications of photovoltaic technology, further enhancement of both device performance and stability are urgently required, particularly for the inverted structure devices, since this architecture will probably be most promising for the possible coming commercialization. In this work, we have fabricated both conventional and inverted structure devices using the same small molecular donor/acceptor materials and compared the performance of both device structures, and found that the inverted structure based device gave significantly improved performance, the highest PCE so far for inverted structure based device using small molecules as the donor. Furthermore, the inverted device shows a remarkable stability with almost no obvious degradation after three months. Systematic device physics and charge generation dynamics studies, including optical simulation, light-intensity-dependent current-voltage experiments, photocurrent density-effective voltage analyses, transient absorption measurements, and electrical simulations, indicate that the significantly enhanced performance using inverted device is ascribed to the increasing of Jsc compared to the conventional device, which in turn is mainly attributed to the increased absorption of photons in the active layers, rather than the reduced nongeminate recombination.

Mechanically durable carbon nanotube-composite hierarchical structures with superhydrophobicity, self-cleaning, and low-drag.

PubMed

Jung, Yong Chae; Bhushan, Bharat

2009-12-22

Superhydrophobic surfaces with high contact angle and low contact angle hysteresis exhibit a self-cleaning effect and low drag for fluid flow. The lotus (Nelumbo nucifera) leaf is one of the examples found in nature for superhydrophobic surfaces. For the development of superhydrophobic surfaces, which is important for various applications such as glass windows, solar panels, and microchannels, materials and fabrication methods need to be explored to provide mechanically durable surfaces. It is necessary to perform durability studies on these surfaces. Carbon nanotube (CNT), composite structures which would lead to superhydrophobicity, self-cleaning, and low-drag, were prepared using a spray method. As a benchmark, structured surfaces with lotus wax were also prepared to compare with the durability of CNT composite structures. To compare the durability of the various fabricated surfaces, waterfall/jet tests were conducted to determine the loss of superhydrophobicity by changing the flow time and pressure conditions. Wear and friction studies were also performed using an atomic force microscope (AFM) and a ball-on-flat tribometer. The changes in the morphology of the structured surfaces were examined by AFM and optical imaging. We find that superhydrophobic CNT composite structures showed good mechanical durability, superior to the structured surfaces with lotus wax, and may be suitable for real world applications.

Reduced variance in monozygous twins for multiple MR parameters: implications for disease studies and the genetic basis of brain structure.

PubMed

Pell, Gaby S; Briellmann, Regula S; Lawrence, Kate M; Glencross, Deborah; Wellard, R Mark; Berkovic, Samuel F; Jackson, Graeme D

2010-01-15

Twin studies offer the opportunity to determine the relative contribution of genes versus environment in traits of interest. Here, we investigate the extent to which variance in brain structure is reduced in monozygous twins with identical genetic make-up. We investigate whether using twins as compared to a control population reduces variability in a number of common magnetic resonance (MR) structural measures, and we investigate the location of areas under major genetic influences. This is fundamental to understanding the benefit of using twins in studies where structure is the phenotype of interest. Twenty-three pairs of healthy MZ twins were compared to matched control pairs. Volume, T2 and diffusion MR imaging were performed as well as spectroscopy (MRS). Images were compared using (i) global measures of standard deviation and effect size, (ii) voxel-based analysis of similarity and (iii) intra-pair correlation. Global measures indicated a consistent increase in structural similarity in twins. The voxel-based and correlation analyses indicated a widespread pattern of increased similarity in twin pairs, particularly in frontal and temporal regions. The areas of increased similarity were most widespread for the diffusion trace and least widespread for T2. MRS showed consistent reduction in metabolite variation that was significant in the temporal lobe N-acetylaspartate (NAA). This study has shown the distribution and magnitude of reduced variability in brain volume, diffusion, T2 and metabolites in twins. The data suggest that evaluation of twins discordant for disease is indeed a valid way to attribute genetic or environmental influences to observed abnormalities in patients since evidence is provided for the underlying assumption of decreased variability in twins.

Anomalous subcortical morphology in boys, but not girls, with ADHD compared to typically developing controls and correlates with emotion dysregulation

PubMed Central

Crocetti, Deana; Mostofsky, Stewart H.; Miller, Michael I.; Rosch, Keri S.

2017-01-01

There has been limited investigation of volume and shape difference in subcortical structures in children with ADHD and a paucity of examination of the influence of sex on these findings. The objective of this study was to examine morphology (volume and shape) of subcortical structures and their association with emotion dysregulation (ED) in girls and boys with ADHD as compared to their typically-developing (TD) counterparts. Participants included 218 children ages 8-12 years old with and without DSM-IV ADHD. Structural magnetic resonance images were obtained, and shape analyses were conducted using large deformation diffeomorphic metric mapping (LDDMM). Compared to TD boys, boys with ADHD showed reduced volumes in the bilateral globus pallidus and amygdala. There were no volumetric differences in any structure between ADHD and TD girls. Shape analysis revealed localized compressions within the globus pallidus, putamen and amygdala in ADHD boys relative to TD boys, as well as significant correlations between increased ED and unique subregion expansion in right globus pallidus, putamen, and right amygdala. Our findings suggest a sexually dimorphic pattern of differences in subcortical structures in children with ADHD compared to TD children, and a possible neurobiological mechanism by which boys with ADHD demonstrate increased difficulties with ED. PMID:28104573

Structural and vibrational spectroscopic analysis of anticancer drug mitotane using DFT method; a comparative study of its parent structure

NASA Astrophysics Data System (ADS)

Mariappan, G.; Sundaraganesan, N.

2015-04-01

A comprehensive screening of the density functional theoretical approach to structural analysis is presented in this section. DFT calculations using B3LYP/6-311++G(d,p) level of theory were found to yield results that are very comparable to experimental IR and Raman spectra. Computed geometrical parameters and harmonic vibrational wavenumbers of the fundamentals were found in satisfactory agreement with the experimental data and also its parent structure. The vibrational assignments of the normal modes were performed on the basis of the potential energy distribution (PED) calculations. It can be proven from the comparative results of mitotane and its parent structure Dichlorodiphenyldichloroethane (DDD), the intramolecular nonbonding interaction between (C1sbnd H19⋯Cl18) in the ortho position which is calculated 2.583 Å and the position of the substitution takeover the vibrational wavenumber to redshift of 47 cm-1. In addition, natural bond orbital (NBO) analysis has been performed for analyzing charge delocalization throughout the molecule. Stability of the molecule arising from hyperconjugative interactions leading to its bioactivity and charge delocalization has been analyzed. 13C and 1H nuclear magnetic resonance chemical shifts of the molecule have been calculated using the gauge independent atomic orbital (GIAO) method and compared with published results.

Bone structure studies with holographic interferometric nondestructive testing and x-ray methods

NASA Astrophysics Data System (ADS)

Silvennoinen, Raimo; Nygren, Kaarlo; Rouvinen, Juha; Petrova, Valentina V.

1994-02-01

Changes in the biomechanics and in the molecular texture and structure of isolated radioulnar bones of subadult European moose (Alces alces L.) collected in various environmentally polluted areas of Finland were investigated by means of holographic interferometric non- destructive testing (HNDT), radiological, morphometrical, and x-ray diffraction methods. By means of small caudal-cranial bending forces, the surface movements of the lower end (distal epiphysis) of the radial bone were recorded with the HNDT method. To study bone molecular texture and structure changes under external compressing forces, the samples for x-ray diffraction analysis were taken from the upper end of the ulnar bone (olecranon tip). Results showed that the bones obtained from the Harjavalta area and those of North Karelian moose showing malnutrition and healing femoral fractures produced different HNDT pictures compared with the four normally developed North Karelian moose. In the x-ray diffraction, the Harjavalta samples showed changes in molecular texture and structure compared with the samples from the apparently normal North Karelian animals.

Relationships between structure and function: System structure matters whether you are in a wetland or a college classroom

NASA Astrophysics Data System (ADS)

Andrews, Sarah Elizabeth

Part I of this dissertation describes two research projects I undertook to understand how structure influences function in freshwater wetlands. In the first study I tested the hypothesis that wetland structure (created versus natural) would influence function (methane cycling). Created wetlands had reduced rates of potential methane production and potential methane oxidation compared to natural wetlands; this was most likely explained by differences in edaphic factors that characterized each wetland, particularly soil moisture and soil organic matter. In the second study (Andrews et al. 2013), I tested the hypothesis that plant community structure (functional group composition, richness, presence/absence) would influence function (methane and iron cycling) in wetland mesocosms. Plant functional group richness was less important than the type of vegetation present: the presence of perennial vegetation (reeds or tussocks) led to increased rates of potential iron reduction compared to when only annual vegetation was present. Part II of this dissertation describes research I undertook to understand how structure influences function in an undergraduate soil science course. In the first study I tested the hypothesis that course structure (traditional versus studio) would influence function (student performance) in the course. Students in the studio course outperformed students in the traditional course; there was also a decrease in the fail rate. In the second study I looked at students' perspectives on their learning and experiences (function) in the studio course and asked whether students' epistemological development influenced this function. Interviews with students revealed that active learning, the integrated nature of the course, community, and variety of learning and assessment methods helped student learning. Students' epistemological development (interpreted from the Measure of Epistemological Reflection) permeated much of what they spoke about during the interviews. There was also evidence that the studio structure may help promote epistemological growth via "sneaky learning" and an expanded role of peers. The studies in Part I show that differences in structure affect function in freshwater wetland systems and the studies in Part II show that structure affects function in an undergraduate introductory soil science course. Thus, system structure matters whether you are in a wetland or a college classroom.

[Comparative analysis of Andean and Caribbean region health systems].

PubMed

Gómez-Camelo, Diana

2005-01-01

Carrying out a comparative analysis of Andean and Caribbean health systems contributing towards the general panorama of Andean and Caribbean region health care system experience. This study was aimed at carrying out a comparative analysis of health systems in Bolivia, Colombia, Ecuador, Peru, Venezuela, the Dominican Republic and Cuba between 1990 and 2004. Documentary information from secondary sources was used. Reform and changes during the aforementioned period were compared, as well as the systems' current configurations. Described typologies were used for studying the health systems. Different organisational designs were found for the systems: a national health system (NHS), segmented systems and systems based on mandatory insurance. The trend of reforms introduced in the 1990s and current proposals in almost all systems are directed towards adopting mandatory insurance via a basic packet of services and strengthening competition in providing services through a public and private mix. The organisation and structure of most systems studied have introduced and continue to introduce changes in line with international guidelines. The generality of these structures means that efforts must still be made to adopt designs strengthening them as instruments improving populations' quality of life. Comparative analysis is a tool leading to studying health systems and producing information which can nourish debate regarding current sector reform. This work took shape during the first approach to a comparative study of Andean region and Caribbean health systems.

How quantitative measures unravel design principles in multi-stage phosphorylation cascades.

PubMed

Frey, Simone; Millat, Thomas; Hohmann, Stefan; Wolkenhauer, Olaf

2008-09-07

We investigate design principles of linear multi-stage phosphorylation cascades by using quantitative measures for signaling time, signal duration and signal amplitude. We compare alternative pathway structures by varying the number of phosphorylations and the length of the cascade. We show that a model for a weakly activated pathway does not reflect the biological context well, unless it is restricted to certain parameter combinations. Focusing therefore on a more general model, we compare alternative structures with respect to a multivariate optimization criterion. We test the hypothesis that the structure of a linear multi-stage phosphorylation cascade is the result of an optimization process aiming for a fast response, defined by the minimum of the product of signaling time and signal duration. It is then shown that certain pathway structures minimize this criterion. Several popular models of MAPK cascades form the basis of our study. These models represent different levels of approximation, which we compare and discuss with respect to the quantitative measures.

Inflight Characterization of the Cassini Spacecraft Propellant Slosh and Structural Frequencies

NASA Technical Reports Server (NTRS)

Lee, Allan Y.; Stupik, Joan

2015-01-01

While there has been extensive theoretical and analytical research regarding the characterization of spacecraft propellant slosh and structural frequencies, there have been limited studies to compare the analytical predictions with measured flight data. This paper uses flight telemetry from the Cassini spacecraft to get estimates of high-g propellant slosh frequencies and the magnetometer boom frequency characteristics, and compares these values with those predicted by theoretical works. Most Cassini attitude control data are available at a telemetry frequency of 0.5 Hz. Moreover, liquid sloshing is attenuated by propellant management device and attitude controllers. Identification of slosh and structural frequency are made on a best-effort basis. This paper reviews the analytical approaches that were used to predict the Cassini propellant slosh frequencies. The predicted frequencies are then compared with those estimated using telemetry from selected Cassini burns where propellant sloshing was observed (such as the Saturn Orbit Insertion burn). Determination of the magnetometer boom structural frequency is also discussed.

Effects of Transfer to Real-World Subject Area Materials from Training in Graphic Organizers and Summarizing on Developmental College Readers' Comprehension of the Compare/Contrast Text Structure in Science Expository Text.

ERIC Educational Resources Information Center

Balajthy, Ernest; Weisberg, Renee

To determine whether less able readers could use the strategies they had been taught, a study investigated the transfer effects of training in the use of graphic organizers and summary writing on readers' recognition of the compare/contrast text structure. Subjects, 70 freshmen at a western New York state college of liberal arts and sciences in a…

Structure-activity relationships of pyrethroid insecticides. Part 2. The use of molecular dynamics for conformation searching and average parameter calculation

NASA Astrophysics Data System (ADS)

Hudson, Brian D.; George, Ashley R.; Ford, Martyn G.; Livingstone, David J.

1992-04-01

Molecular dynamics simulations have been performed on a number of conformationally flexible pyrethroid insecticides. The results indicate that molecular dynamics is a suitable tool for conformational searching of small molecules given suitable simulation parameters. The structures derived from the simulations are compared with the static conformation used in a previous study. Various physicochemical parameters have been calculated for a set of conformations selected from the simulations using multivariate analysis. The averaged values of the parameters over the selected set (and the factors derived from them) are compared with the single conformation values used in the previous study.

Experimental Studies on Wave Interactions of Partially Perforated Wall under Obliquely Incident Waves

PubMed Central

Lee, Jong-In; Kim, Young-Taek; Shin, Sungwon

2014-01-01

This study presents wave height distribution in terms of stem wave evolution phenomena on partially perforated wall structures through three-dimensional laboratory experiments. The plain and partially perforated walls were tested to understand their effects on the stem wave evolution under the monochromatic and random wave cases with the various wave conditions, incident angle (from 10 to 40 degrees), and configurations of front and side walls. The partially perforated wall reduced the relative wave heights more effectively compared to the plain wall structure. Partially perforated walls with side walls showed a better performance in terms of wave height reduction compared to the structure without the side wall. Moreover, the relative wave heights along the wall were relatively small when the relative chamber width is large, within the range of the chamber width in this study. The wave spectra showed a frequency dependency of the wave energy dissipation. In most cases, the existence of side wall is a more important factor than the porosity of the front wall in terms of the wave height reduction even if the partially perforated wall was still effective compared to the plain wall. PMID:25254260

Structural, quantum chemical, vibrational and thermal studies of a hydrogen bonded zwitterionic co-crystal (nicotinic acid: pyrogallol)

NASA Astrophysics Data System (ADS)

Prabha, E. Arockia Jeya Yasmi; Kumar, S. Suresh; Athimoolam, S.; Sridhar, B.

2017-02-01

In the present work, a new co-crystal of nicotinic acid with pyrogallol (NICPY) has been grown in the zwitterionic form and the corresponding structural, vibrational, thermal, solubility and anti-cancer characteristics have been reported. The single crystal X-ray diffraction analysis confirms that the structural molecular packing of the crystal stabilized through N-H⋯O and O-H⋯O hydrogen bond. The stabilization energy of the hydrogen bond motifs were calculated in the solid state. Vibrational spectral studies such as Fourier transform-infrared (FT-IR) and FT-Raman were adopted to understand the zwitterionic co-crystalline nature of the compound, which has been compared with theoretically calculated vibrational frequencies. The thermal stability of the grown co-crystal was analyzed by TG/DTA study. The solubility of the NICPY co-crystal was investigated in water at different temperature and compared with that of the nicotinic acid, which is the parent compound of NICPY co-crystal. The grown crystals were treated with human cervical cancer cell line (HeLa) to analyze the cytotoxicity of NICPY crystals and compared with the parent compound, which shows that NICPY has moderate activity against human cervical cancer cell line.

Experimental studies on wave interactions of partially perforated wall under obliquely incident waves.

PubMed

Lee, Jong-In; Kim, Young-Taek; Shin, Sungwon

2014-01-01

This study presents wave height distribution in terms of stem wave evolution phenomena on partially perforated wall structures through three-dimensional laboratory experiments. The plain and partially perforated walls were tested to understand their effects on the stem wave evolution under the monochromatic and random wave cases with the various wave conditions, incident angle (from 10 to 40 degrees), and configurations of front and side walls. The partially perforated wall reduced the relative wave heights more effectively compared to the plain wall structure. Partially perforated walls with side walls showed a better performance in terms of wave height reduction compared to the structure without the side wall. Moreover, the relative wave heights along the wall were relatively small when the relative chamber width is large, within the range of the chamber width in this study. The wave spectra showed a frequency dependency of the wave energy dissipation. In most cases, the existence of side wall is a more important factor than the porosity of the front wall in terms of the wave height reduction even if the partially perforated wall was still effective compared to the plain wall.

Comparative study on stiffness properties of WOODCAST and conventional casting materials.

PubMed

Pirhonen, Eija; Pärssinen, Antti; Pelto, Mika

2013-08-01

Plaster-of-Paris and synthetic materials (e.g. fibreglass) have been in clinical use as casting materials for decades. An innovative casting material, WOODCAST, brings interesting alternatives to the traditional materials. The aim of this study was to compare the stiffness properties of the WOODCAST material to traditional casting materials. In immobilization by casting, materials with variable stiffness properties are required. Ring stiffness of cylindrical samples correlates well with cast rigidity. For load-bearing structures, the use of the WOODCAST Splint is recommended as equally high stiffness was obtained with the WOODCAST Splint as was with fibreglass. The WOODCAST 2 mm product is optimal for structures where some elasticity is required, and WOODCAST Ribbon can be used in any WOODCAST structure where further reinforcement is needed. The results show that WOODCAST material can be used in replacing traditional casting materials used in extremity immobilization. The mechanical properties of casting material play an important role in safe and effective fracture immobilization. Stiffness properties of the WOODCAST casting material and conventional materials - fibreglass and plaster-of-Paris - were analysed in this study. The WOODCAST Splint appears to compare favorably with traditional materials such as Scotchcast.

Comparative dynamics in a health investment model.

PubMed

Eisenring, C

1999-10-01

The method of comparative dynamics fully exploits the inter-temporal structure of optimal control models. I derive comparative dynamic results in a simplified demand for health model. The effect of a change in the depreciation rate on the optimal paths for health capital and investment in health is studied by use of a phase diagram.

Asymmetric bias in user guided segmentations of brain structures

NASA Astrophysics Data System (ADS)

Styner, Martin; Smith, Rachel G.; Graves, Michael M.; Mosconi, Matthew W.; Peterson, Sarah; White, Scott; Blocher, Joe; El-Sayed, Mohammed; Hazlett, Heather C.

2007-03-01

Brain morphometric studies often incorporate comparative asymmetry analyses of left and right hemispheric brain structures. In this work we show evidence that common methods of user guided structural segmentation exhibit strong left-right asymmetric biases and thus fundamentally influence any left-right asymmetry analyses. We studied several structural segmentation methods with varying degree of user interaction from pure manual outlining to nearly fully automatic procedures. The methods were applied to MR images and their corresponding left-right mirrored images from an adult and a pediatric study. Several expert raters performed the segmentations of all structures. The asymmetric segmentation bias is assessed by comparing the left-right volumetric asymmetry in the original and mirrored datasets, as well as by testing each sides volumetric differences to a zero mean standard t-tests. The structural segmentations of caudate, putamen, globus pallidus, amygdala and hippocampus showed a highly significant asymmetric bias using methods with considerable manual outlining or landmark placement. Only the lateral ventricle segmentation revealed no asymmetric bias due to the high degree of automation and a high intensity contrast on its boundary. Our segmentation methods have been adapted in that they are applied to only one of the hemispheres in an image and its left-right mirrored image. Our work suggests that existing studies of hemispheric asymmetry without similar precautions should be interpreted in a new, skeptical light. Evidence of an asymmetric segmentation bias is novel and unknown to the imaging community. This result seems less surprising to the visual perception community and its likely cause is differences in perception of oppositely curved 3D structures.

Ab Initio Study of Interfacial Structure Transformation of Amorphous Carbon Catalyzed by Ti, Cr, and W Transition Layers.

PubMed

Li, Xiaowei; Li, Lei; Zhang, Dong; Wang, Aiying

2017-11-29

Amorphous carbon (a-C) films composited with transition layers exhibit the desirable improvement of adhesion strength between films and substrate, but the further understanding on the interfacial structure transformation of a-C structure induced by transition layers is still lacked. In this paper, using ab initio calculations, we comparatively studied the interfacial structure between Ti, Cr, or W transition layers and a-C film from the atomic scale, and demonstrated that the addition of Ti, Cr, or W catalyzed the graphitic transformation of a-C structure at different levels, which provided the theoretical guidance for designing a multilayer nanocomposite film for renewed application.

POD/MAC-Based Modal Basis Selection for a Reduced Order Nonlinear Response Analysis

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Przekop, Adam

2007-01-01

A feasibility study was conducted to explore the applicability of a POD/MAC basis selection technique to a nonlinear structural response analysis. For the case studied the application of the POD/MAC technique resulted in a substantial improvement of the reduced order simulation when compared to a classic approach utilizing only low frequency modes present in the excitation bandwidth. Further studies are aimed to expand application of the presented technique to more complex structures including non-planar and two-dimensional configurations. For non-planar structures the separation of different displacement components may not be necessary or desirable.

Molecular dynamics simulation of the thermosensitivity of the human connexin 26 hemichannel

NASA Astrophysics Data System (ADS)

Alizadeh, Hadi; Davoodi, Jamal; Zeilinger, Carsten; Rafii-Tabar, Hashem

2018-01-01

Connexin hemichannels mediate cytoplasm and extracellular milieu communication by exchanging a variety of cytoplasmic molecules and ions. These hemichannels can be regulated by external stimuli such as mechanical stress, applied voltage, pH and temperature changes. Although there are many studies on structures and functions of connexin 26 in contexts of pH, ion concentration and voltage, employing computational methods, no such study has been performed so far involving temperature changes. In this study, using molecular dynamics simulation, we investigate thermosensitivity of the human Connexin 26 hemichannel. Our results show that the channel approaches a structurally closed state at lower temperature compared to higher temperature. This is in fair agreement with experimental results that indicate channel closure at lower temperature. Furthermore, our MD simulation results show that some regions of connexin 26 hemichannel are more sensitive to temperature compared to other regions. Whereas the intercellular half of the channel does not show any considerable response to temperature during the simulation time accessible in this study, the cytoplasmic half approaches a closed structural state at lower temperature compared to the higher temperature. Specifically, our results suggest that the cytoplasmic loop, the cytoplasmic half of the second transmembrane helix, and the N-terminus helix play a dominant role in temperature gating.

A comparative study on book shelf structure based on different domain modal analysis

NASA Astrophysics Data System (ADS)

Sabamehr, Ardalan; Roy, Timir Baran; Bagchi, Ashutosh

2017-04-01

Structural Health Monitoring (SHM) based on the vibration of structures has been very attractive topic for researchers in different fields such as: civil, aeronautical and mechanical engineering. The aim of this paper is to compare three most common modal identification techniques such as Frequency Domain Decomposition (FDD), Stochastic Subspace Identification (SSI) and Continuous Wavelet Transform (CWT) to find modal properties (such as natural frequency, mode shape and damping ratio) of three story book shelf steel structure which was built in Concordia University Lab. The modified Complex Morlet wavelet have been selected for wavelet in order to use asymptotic signal rather than real one with variable bandwidth and wavelet central frequency. So, CWT is able to detect instantaneous modulus and phase by use of local maxima ridge detection.

The crustal tectonics and history of Europa: A structural, morphological, and comparative analysis. M.S. Thesis

NASA Technical Reports Server (NTRS)

Schenk, P. M.

1984-01-01

An evaluation of surface features and structures on the Galilean moon Europa is made using the available high resolution Voyager imagery, low resolution support imaging, and what understanding of ice structure and mechanical behavior science has that is applicable to the problem. A general discussion of the history of Europa studies and the fundamental global morphology is undertaken. The visible lineament and terrain patterns are described, and possible origins discussed. Observations of faulting and block rotation previously described are amplified. A comparison of Europa's structures to terrestrial sea ice and lava lake crust features is also included. Finally, an attempt is made at synthesizing a unified model for the evolution of Europa's crust is presented which is compared with models developed by others.

Postbuckling behavior of graphite-epoxy panels

NASA Technical Reports Server (NTRS)

Starnes, J. H., Jr.; Dickson, J. N.; Rouse, M.

1984-01-01

Structurally efficient fuselage panels are often designed to allow buckling to occur at applied loads below ultimate. Interest in applying graphite-epoxy materials to fuselage primary structure led to several studies of the post-buckling behavior of graphite-epoxy structural components. Studies of the postbuckling behavior of flat and curved, unstiffened and stiffened graphite-epoxy panels loaded in compression and shear were summarized. The response and failure characteristics of specimens studied experimentally were described, and analytical and experimental results were compared. The specimens tested in the studies described were fabricated from commercially available 0.005-inch-thick unidirectional graphite-fiber tapes preimpregnated with 350 F cure thermosetting epoxy resins.

Leisure activities are linked to mental health benefits by providing time structure: comparing employed, unemployed and homemakers.

PubMed

Goodman, William K; Geiger, Ashley M; Wolf, Jutta M

2017-01-01

Unemployment has consistently been linked to negative mental health outcomes, emphasising the need to characterise the underlying mechanisms. The current study aimed at testing whether compared with other employment groups, fewer leisure activities observed in unemployment may contribute to elevated risk for negative mental health via loss of time structure. Depressive symptoms (Center for Epidemiologic Studies Depression), leisure activities (exercise, self-focused, social), and time structure (Time Structure Questionnaire (TSQ)) were assessed cross-sectionally in 406 participants (unemployed=155, employed=140, homemakers=111) recruited through Amazon Mechanical Turk. Controlling for gender and age, structural equation modelling revealed time structure partially (employed, homemakers) and fully (unemployed) mediated the relationship between leisure activities and depressive symptoms. With the exception of differential effects for structured routines, all other TSQ factors (sense of purpose, present orientation, effective organisation and persistence) contributed significantly to all models. These findings support the idea that especially for the unemployed, leisure activities impose their mental health benefits through increasing individuals' perception of spending their time effectively. Social leisure activities that provide a sense of daily structure may thereby be a particularly promising low-cost intervention to improve mental health in this population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Impact of Structured Movement Time on Preschoolers' Physical Activity Engagement

ERIC Educational Resources Information Center

Palmer, Kara K.; Matsuyama, Abigail L.; Robinson, Leah E.

2017-01-01

Preschool-aged children are not meeting national physical activity recommendations. This study compares preschoolers' physical activity engagement during two different physical activity opportunities: outdoor free play or a structured movement session. Eighty-seven children served as participants: 40 children participated in outdoor free play and…

Resting habitat selection by fishers in California

Treesearch

William J. Zielinski; Richard L. Truex; Gregory A. Schmidt; Fredrick V. Schlexer; Kristin N. Schmidt; Reginald H. Barrett

2004-01-01

We studied the resting habitat ecology of fishers (Martes pennanti) in 2 disjunct populations in California, USA: the northwestern coastal mountains (hereafter, Coastal) and the southern Sierra Nevada (hereafter, Sierra). We described resting structures and compared features surrounding resting structures (the resting site) with those at randomly...

A study of tantalum pentoxide Ta 2O 5 structures up to 28 GPa

DOE PAGES

Stavrou, Elissaios; Zaug, Joseph M.; Bastea, Sorin; ...

2017-05-02

In this study, tantalum pentoxide Ta 2O 5 with the orthorhombic L-Ta 2O 5 structure has been experimentally studied up to 28.3 GPa (at ambient temperature) using synchrotron angle-dispersive powder X-ray diffraction (XRD). The ambient pressure phase remains stable up to 25 GPa where with increased pressure a crystalline to amorphous phase transition occurs. A detailed equation of state (EOS), including pressure dependent lattice parameters, is reported. The results of this study were compared with a previous high-pressure XRD study by Li et al. A clear discrepancy between the ambient-pressure crystal structures and, consequently, the reported EOSs between the twomore » studies was revealed. Finally, he origin of this discrepancy is attributed to two different crystal structures used to index the XRD patterns.« less

Structured nursing follow-up: does it help in diabetes care?

PubMed Central

2014-01-01

Background In 1995 Clalit Health Services introduced a structured follow-up schedule, by primary care nurses, of diabetic patients. This was supplementary care, given in addition to the family physician’s follow-up care. This article aims to describe the performance of diabetes follow-up and diabetes control in patients with additional structured nursing follow-up care, compared to those patients followed only by their family physician. Methods We randomly selected 2,024 type 2 diabetic subjects aged 40–76 years. For each calendar year, from 2005–2007, patients who were “under physician follow-up only” were compared to those who received additional structured nursing follow-up care. Main outcomes Complete diabetes follow-up parameters including: HbA1c, LDL cholesterol, microalbumin, blood pressure measurements and fundus examination. Results The average age of study participants was 60.7 years, 52% were females and 38% were from low socioeconomic status (SES). In 2005, 39.5% of the diabetic patients received structured nursing follow-up, and the comparable figures for 2006 and 2007 were 42.1% 49.6%, respectively. The intervention subjects tended to be older, from lower SES, suffered from more chronic diseases and visited their family physician more frequently than the control patients. Patients in the study group were more likely to perform a complete diabetes follow-up plan: 52.8% vs. 21.5% (2005; p < 0.001) 55.5% vs. 30.3% (2006; p < 0.001), 52.3% vs. 35.7% (2007; p < 0.001). LDL cholesterol levels were lower in the study group only in 2005: 103.7 vs. 110.0 p < 0.001. Conclusion Subjects with supplementary structured nursing follow-up care were more likely to perform complete diabetes follow-up protocol. Our results reinforce the importance of teamwork in diabetic care. Further study is required to identify strategies for channeling the use of the limited resources to the patients who stand to benefit the most. PMID:25180073

Performance of optimum detector structures for noisy intersymbol interference channels

NASA Technical Reports Server (NTRS)

Womer, J. D.; Fritchman, B. D.; Kanal, L. N.

1971-01-01

The errors which arise in transmitting digital information by radio or wireline systems because of additive noise from successively transmitted signals interfering with one another are described. The probability of error and the performance of optimum detector structures are examined. A comparative study of the performance of certain detector structures and approximations to them, and the performance of a transversal equalizer are included.

Tree microhabitat structures as indicators of biodiversity in Douglas-fir forests of different stand ages and management histories in the Pacific Northwest, U.S.A.

Treesearch

Alexa K. Michel; Susanne Winter

2009-01-01

In this study, microhabitat structures in Douglas-fir (Pseudotsuga menziesii) forests were defined and their frequency and abundance in natural stands and stands of varying active management histories and stand ages was compared. Indicator microhabitat structures for natural forests were determined and the relationship of the abundance of...

Optimization of MLS receivers for multipath environments

NASA Technical Reports Server (NTRS)

Mcalpine, G. A.; Irwin, S. H.; NELSON; Roleyni, G.

1977-01-01

Optimal design studies of MLS angle-receivers and a theoretical design-study of MLS DME-receivers are reported. The angle-receiver results include an integration of the scan data processor and tracking filter components of the optimal receiver into a unified structure. An extensive simulation study comparing the performance of the optimal and threshold receivers in a wide variety of representative dynamical interference environments was made. The optimal receiver was generally superior. A simulation of the performance of the threshold and delay-and-compare receivers in various signal environments was performed. An analysis of combined errors due to lateral reflections from vertical structures with small differential path delays, specular ground reflections with neglible differential path delays, and thermal noise in the receivers is provided.

Structure-activity relationship of the ionic cocrystal: 5-amino-2-naphthalene sulfonate·ammonium ions for pharmaceutical applications

NASA Astrophysics Data System (ADS)

Sangeetha, M.; Mathammal, R.

2018-02-01

The ionic cocrystals of 5-amino-2-naphthalene sulfonate · ammonium ions (ANSA-ṡNH4+) were grown under slow evaporation method and examined in detail for pharmaceutical applications. The crystal structure and intermolecular interactions were studied from the single X-ray diffraction analysis and the Hirshfeld surfaces. The 2D fingerprint plots displayed the inter-contacts possible in the ionic crystal. Computational DFT method was established to determine the structural, physical and chemical properties. The molecular geometries obtained from the X-ray studies were compared with the optimized geometrical parameters calculated using DFT/6-31 + G(d,p) method. The band gap energy calculated from the UV-Visible spectral analysis and the HOMO-LUMO energy gap are compared. The theoretical UV-Visible calculations helped in determining the type of electronic transition taking place in the title molecule. The maximum absorption bands and transitions involved in the molecule represented the drug reaction possible. Non-linear optical properties were characterized from SHG efficiency measurements experimentally and the NLO parameters are also calculated from the optimized structure. The reactive sites within the molecule are detailed from the MEP surface maps. The molecular docking studies evident the structure-activity of the ionic cocrystal for anti-cancer drug property.

New and Improved? A Comparison of the Original and Revised Versions of the Structured Interview of Reported Symptoms

ERIC Educational Resources Information Center

Green, Debbie; Rosenfeld, Barry; Belfi, Brian

2013-01-01

The current study evaluated the accuracy of the Structured Interview of Reported Symptoms, Second Edition (SIRS-2) in a criterion-group study using a sample of forensic psychiatric patients and a community simulation sample, comparing it to the original SIRS and to results published in the SIRS-2 manual. The SIRS-2 yielded an impressive…

Anterolateral ligament anatomy: a comparative anatomical study.

PubMed

Ingham, Sheila Jean McNeill; de Carvalho, Rogerio Teixeira; Martins, Cesar A Q; Lertwanich, Pisit; Abdalla, Rene Jorge; Smolinski, Patrick; Lovejoy, C Owen; Fu, Freddie H

2017-04-01

Some anatomical studies have indicated that the anterolateral ligament (ALL) of the knee is distinct ligamentous structure in humans. The purpose of this study is to compare the lateral anatomy of the knee among human and various animal specimens. Fifty-eight fresh-frozen knee specimens, from 24 different animal species, were used for this anatomical study. The same researchers dissected all the specimens in this study, and dissections were performed in a careful and standardized manner. An ALL was not found in any of the 58 knees dissected. Another interesting finding in this study is that some primate species (the prosimians: the red and black and white lemurs) have two LCLs. The clinical relevance of this study is the lack of isolation of the ALL as a unique structure in animal species. Therefore, precaution is recommended before assessing the need for surgery to reconstruct the ALL as a singular ligament.

Design and preliminary structure-activity relationship of redox-silent semisynthetic tocotrienol analogues as inhibitors for breast cancer proliferation and invasion.

PubMed

Elnagar, Ahmed Y; Wali, Vikram B; Sylvester, Paul W; El Sayed, Khalid A

2010-01-15

Vitamin E (VE) is a generic term that represents a family of compounds composed of various tocopherol and tocotrienol isoforms. Tocotrienols display potent anti-angiogenic and antiproliferative activities. Redox-silent tocotrienol analogues also display potent anticancer activity. The ultimate objective of this study was to develop semisynthetically C-6-modified redox-silent tocotrienol analogues with enhanced antiproliferative and anti-invasive activities as compared to their parent compound. Examples of these are carbamate and ether analogues of alpha-, gamma-, and delta-tocotrienols (1-3). Various aliphatic, olefinic, and aromatic substituents were used. Steric limitation, electrostatic, hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) properties were varied at this position and the biological activities of these derivatives were tested. Three-dimensional quantitative structure-activity relationship (3D QSAR) studies were performed using Comparative Molecular Field (CoMFA) and Comparative Molecular Similarity Indices Analyses (CoMSIA) to better understand the structural basis for biological activity and guide the future design of more potent VE analogues. Copyright 2009 Elsevier Ltd. All rights reserved.

Methods in the study of discrete upper hybrid waves

NASA Astrophysics Data System (ADS)

Yoon, P. H.; Ye, S.; Labelle, J.; Weatherwax, A. T.; Menietti, J. D.

2007-11-01

Naturally occurring plasma waves characterized by fine frequency structure or discrete spectrum, detected by satellite, rocket-borne instruments, or ground-based receivers, can be interpreted as eigenmodes excited and trapped in field-aligned density structures. This paper overviews various theoretical methods to study such phenomena for a one-dimensional (1-D) density structure. Among the various methods are parabolic approximation, eikonal matching, eigenfunction matching, and full numerical solution based upon shooting method. Various approaches are compared against the full numerical solution. Among the analytic methods it is found that the eigenfunction matching technique best approximates the actual numerical solution. The analysis is further extended to 2-D geometry. A detailed comparative analysis between the eigenfunction matching and fully numerical methods is carried out for the 2-D case. Although in general the two methods compare favorably, significant differences are also found such that for application to actual observations it is prudent to employ the fully numerical method. Application of the methods developed in the present paper to actual geophysical problems will be given in a companion paper.

Seeing tobacco mosaic virus through direct electron detectors

PubMed Central

Fromm, Simon A.; Bharat, Tanmay A.M.; Jakobi, Arjen J.; Hagen, Wim J.H.; Sachse, Carsten

2015-01-01

With the introduction of direct electron detectors (DED) to the field of electron cryo-microscopy, a wave of atomic-resolution structures has become available. As the new detectors still require comparative characterization, we have used tobacco mosaic virus (TMV) as a test specimen to study the quality of 3D image reconstructions from data recorded on the two direct electron detector cameras, K2 Summit and Falcon II. Using DED movie frames, we explored related image-processing aspects and compared the performance of micrograph-based and segment-based motion correction approaches. In addition, we investigated the effect of dose deposition on the atomic-resolution structure of TMV and show that radiation damage affects negative carboxyl chains first in a side-chain specific manner. Finally, using 450,000 asymmetric units and limiting the effects of radiation damage, we determined a high-resolution cryo-EM map at 3.35 Å resolution. Here, we provide a comparative case study of highly ordered TMV recorded on different direct electron detectors to establish recording and processing conditions that enable structure determination up to 3.2 Å in resolution using cryo-EM. PMID:25528571

The leader peptide of mutacin 1140 has distinct structural components compared to related class I lantibiotics.

PubMed

Escano, Jerome; Stauffer, Byron; Brennan, Jacob; Bullock, Monica; Smith, Leif

2014-12-01

Lantibiotics are ribosomally synthesized peptide antibiotics composed of an N-terminal leader peptide that promotes the core peptide's interaction with the post translational modification (PTM) enzymes. Following PTMs, mutacin 1140 is transported out of the cell and the leader peptide is cleaved to yield the antibacterial peptide. Mutacin 1140 leader peptide is structurally unique compared to other class I lantibiotic leader peptides. Herein, we further our understanding of the structural differences of mutacin 1140 leader peptide with regard to other class I leader peptides. We have determined that the length of the leader peptide is important for the biosynthesis of mutacin 1140. We have also determined that mutacin 1140 leader peptide contains a novel four amino acid motif compared to related lantibiotics. PTM enzyme recognition of the leader peptide appears to be evolutionarily distinct from related class I lantibiotics. Our study on mutacin 1140 leader peptide provides a basis for future studies aimed at understanding its interaction with the PTM enzymes. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

RNA-SSPT: RNA Secondary Structure Prediction Tools.

PubMed

Ahmad, Freed; Mahboob, Shahid; Gulzar, Tahsin; Din, Salah U; Hanif, Tanzeela; Ahmad, Hifza; Afzal, Muhammad

2013-01-01

The prediction of RNA structure is useful for understanding evolution for both in silico and in vitro studies. Physical methods like NMR studies to predict RNA secondary structure are expensive and difficult. Computational RNA secondary structure prediction is easier. Comparative sequence analysis provides the best solution. But secondary structure prediction of a single RNA sequence is challenging. RNA-SSPT is a tool that computationally predicts secondary structure of a single RNA sequence. Most of the RNA secondary structure prediction tools do not allow pseudoknots in the structure or are unable to locate them. Nussinov dynamic programming algorithm has been implemented in RNA-SSPT. The current studies shows only energetically most favorable secondary structure is required and the algorithm modification is also available that produces base pairs to lower the total free energy of the secondary structure. For visualization of RNA secondary structure, NAVIEW in C language is used and modified in C# for tool requirement. RNA-SSPT is built in C# using Dot Net 2.0 in Microsoft Visual Studio 2005 Professional edition. The accuracy of RNA-SSPT is tested in terms of Sensitivity and Positive Predicted Value. It is a tool which serves both secondary structure prediction and secondary structure visualization purposes.

RNA-SSPT: RNA Secondary Structure Prediction Tools

PubMed Central

Ahmad, Freed; Mahboob, Shahid; Gulzar, Tahsin; din, Salah U; Hanif, Tanzeela; Ahmad, Hifza; Afzal, Muhammad

2013-01-01

The prediction of RNA structure is useful for understanding evolution for both in silico and in vitro studies. Physical methods like NMR studies to predict RNA secondary structure are expensive and difficult. Computational RNA secondary structure prediction is easier. Comparative sequence analysis provides the best solution. But secondary structure prediction of a single RNA sequence is challenging. RNA-SSPT is a tool that computationally predicts secondary structure of a single RNA sequence. Most of the RNA secondary structure prediction tools do not allow pseudoknots in the structure or are unable to locate them. Nussinov dynamic programming algorithm has been implemented in RNA-SSPT. The current studies shows only energetically most favorable secondary structure is required and the algorithm modification is also available that produces base pairs to lower the total free energy of the secondary structure. For visualization of RNA secondary structure, NAVIEW in C language is used and modified in C# for tool requirement. RNA-SSPT is built in C# using Dot Net 2.0 in Microsoft Visual Studio 2005 Professional edition. The accuracy of RNA-SSPT is tested in terms of Sensitivity and Positive Predicted Value. It is a tool which serves both secondary structure prediction and secondary structure visualization purposes. PMID:24250115

The function and evolution of male and female genitalia in Phyllophaga Harris scarab beetles (Coleoptera: Scarabaeidae).

PubMed

Richmond, M P; Park, J; Henry, C S

2016-11-01

Genitalia diversity in insects continues to fuel investigation of the function and evolution of these dynamic structures. Whereas most studies have focused on variation in male genitalia, an increasing number of studies on female genitalia have uncovered comparable diversity among females, but often at a much finer morphological scale. In this study, we analysed the function and evolution of male and female genitalia in Phyllophaga scarab beetles, a group in which both sexes exhibit genitalic diversity. To document the interaction between male and female structures during mating, we dissected flash-frozen mating pairs from three Phyllophaga species and investigated fine-scale morphology using SEM. We then reconstructed ancestral character states using a species tree inferred from mitochondrial and nuclear loci to elucidate and compare the evolutionary history of male and female genitalia. Our dissections revealed an interlocking mechanism of the female pubic process and male parameres that appears to improve the mechanical fit of the copulatory position. The comparative analyses, however, did not support coevolution of male and female structures and showed more erratic evolution of the female genitalia relative to males. By studying a group that exhibits obvious female genitalic diversity, we were able to demonstrate the relevance of female reproductive morphology in studies of male genital diversity. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Improving the Factor Structure of Psychological Scales

PubMed Central

Zhang, Xijuan; Savalei, Victoria

2015-01-01

Many psychological scales written in the Likert format include reverse worded (RW) items in order to control acquiescence bias. However, studies have shown that RW items often contaminate the factor structure of the scale by creating one or more method factors. The present study examines an alternative scale format, called the Expanded format, which replaces each response option in the Likert scale with a full sentence. We hypothesized that this format would result in a cleaner factor structure as compared with the Likert format. We tested this hypothesis on three popular psychological scales: the Rosenberg Self-Esteem scale, the Conscientiousness subscale of the Big Five Inventory, and the Beck Depression Inventory II. Scales in both formats showed comparable reliabilities. However, scales in the Expanded format had better (i.e., lower and more theoretically defensible) dimensionalities than scales in the Likert format, as assessed by both exploratory factor analyses and confirmatory factor analyses. We encourage further study and wider use of the Expanded format, particularly when a scale’s dimensionality is of theoretical interest. PMID:27182074

Comparative Study of the academic performance between different curricula in Agricultural Engineering

NASA Astrophysics Data System (ADS)

Vazquez, J. L.; Serrano, A.; Caniego, J.

2012-04-01

Due to the introduction of new degrees on the College of Agricultural Engineering of the Technical University of Madrid adapted to the European Space for Higher Education (Bologna), we have made a comparative study of academic achievement obtained by the students during their first year at the Centre according to different curricula. We used data from 2 curricula leading to the degree in Agricultural Engineering, Curriculumn 74 (6 years and annual structure) and Curriculum 96 modified in 2006 (5 years with quarterly structure) and the new curriculum in grades (4 years semi-structured). It has been used as a data source, the qualifications of new students during the last three years prior to the extinction of the curriculum.The study shows that current rates of academic success or failure and dropout during the first year of college are very similar to those happening 12 years ago, when it was assumed that the preparation of students from high school was much higher than today. Keywords: Academic performance, curricula, Bologna.

The Influence of Interactions and Minor Mergers on the Structure of Galactic Disks

NASA Astrophysics Data System (ADS)

Schwarzkopf, U.

1999-07-01

A detailed statistical study is presented focused on the effects of minor mergers and tidal interactions on the radial and vertical structure of galactic disks. The fundamental disk parameters of 112 highly-inclined/edge-on galaxies are studied in optical and in near-infrared passbands. This sample consists of two subsamples of 65 non-interacting and 47 interacting/merging galaxies. Additionally, 41 of these galaxies were observed in the near-infrared. A 3-dimensional disk modelling and -fitting procedure was applied in order to analyze and to compare characteristic disk parameters of all sample galaxies. Furthermore, n-body simulations were performed in order to study the influence of minor mergers in the mass range Msat/Mdisk 0.1 on the vertical structure of disks in spiral galaxies. In particular, the dependence of vertical, tidally-triggered disk thickening on initial disk parameters is investigated. The quantitative results of both simulation and observation are compared in order to find similarities in the distribution of characteristic disk parameters.

Quantifiable Assessment of SWNT Dispersion in Polymer Composites

NASA Technical Reports Server (NTRS)

Park, Cheol; Kim, Jae-Woo; Wise, Kristopher E.; Working, Dennis; Siochi, Mia; Harrison, Joycelyn; Gibbons, Luke; Siochi, Emilie J.; Lillehei, Peter T.; Cantrell, Sean;

Synthesis and crystal structure analysis of uranyl triple acetates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klepov, Vladislav V., E-mail: vladislavklepov@gmail.com; Department of Chemistry, Samara National Research University, 443086 Samara; Serezhkina, Larisa B.

2016-12-15

Single crystals of triple acetates NaR[UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 3}·6H{sub 2}O (R=Mg, Co, Ni, Zn), well-known for their use as reagents for sodium determination, were grown from aqueous solutions and their structural and spectroscopic properties were studied. Crystal structures of the mentioned phases are based upon (Na[UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 3}){sup 2–} clusters and [R(H{sub 2}O){sub 6}]{sup 2+} aqua-complexes. The cooling of a single crystal of NaMg[UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 3}·6H{sub 2}O from 300 to 100 K leads to a phase transition from trigonal to monoclinic crystal system. Intermolecular interactions between the structural units and their mutual packing were studiedmore » and compared from the point of view of the stereoatomic model of crystal structures based on Voronoi-Dirichlet tessellation. Using this method we compared the crystal structures of the triple acetates with Na[UO{sub 2}(CH{sub 3}COO){sub 3}] and [R(H{sub 2}O){sub 6}][UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 2} and proposed reasons of triple acetates stability. Infrared and Raman spectra were collected and their bands were assigned. - Graphical abstract: Single crystals of uranium based triple acetates, analytical reagents for sodium determination, were synthesized and structurally, spectroscopically and topologically characterized. The structures were compared with the structures of compounds from preceding families [M(H{sub 2}O){sub 6})][UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 2} (M = Mg, Co, Ni, Zn) and Na[UO{sub 2}(CH{sub 3}COO){sub 3}]. Analysis was performed with the method of molecular Voronoi-Dirichlet polyhedra to reveal a large contribution of the hydrogen bonds into intermolecular interactions which can be a reason of low solubility of studied complexes.« less

The Effect of Lesson Structures on Predication and Inference.

ERIC Educational Resources Information Center

Li, Tiancheng; Jonassen, David H.

Theories of situated learning attempt to overcome the ill-structured nature of some domains of learning, and to use students' tendencies to construct knowledge representation on context and prior experience. Success comes when students apply abstract principles to real life. This study compares the effectiveness of two different lesson structures…

Brief Report: CANTAB Performance and Brain Structure in Pediatric Patients with Asperger Syndrome

ERIC Educational Resources Information Center

Kaufmann, Liane; Zotter, Sibylle; Pixner, Silvia; Starke, Marc; Haberlandt, Edda; Steinmayr-Gensluckner, Maria; Egger, Karl; Schocke, Michael; Weiss, Elisabeth M.; Marksteiner, Josef

2013-01-01

By merging neuropsychological (CANTAB/Cambridge Neuropsychological Test Automated Battery) and structural brain imaging data (voxel-based-morphometry) the present study sought to identify the neurocognitive correlates of executive functions in individuals with Asperger syndrome (AS) compared to healthy controls. Results disclosed subtle group…

Developmental Trajectories of Structural and Pragmatic Language Skills in School-Aged Children with Williams Syndrome

ERIC Educational Resources Information Center

Van Den Heuvel, E.; Manders, E.; Swillen, A.; Zink, I.

2016-01-01

Background: This study aimed to compare developmental courses of structural and pragmatic language skills in school-aged children with Williams syndrome (WS) and children with idiopathic intellectual disability (IID). Comparison of these language trajectories could highlight syndrome-specific developmental features. Method: Twelve monolingual…

Going off Script: Structure and Agency in Individualized Education Program Meetings

ERIC Educational Resources Information Center

Bray, Laura E.; Russell, Jennifer Lin

2016-01-01

In this comparative case study, we draw from neoinstitutional and structuration theory to examine the individualized education program (IEP) meetings for five high school students identified with specific learning disabilities. Specifically, we examine how participants interacted during the IEP meetings and how learning, instruction, and…

The Alignment of Technology and Structure through Roles and Networks.

ERIC Educational Resources Information Center

Barley, Stephen R.

1990-01-01

Building on Nagel's theory of social structure, this paper argues that the microsocial dynamics occasioned by new technologies systematically reverberate up levels of analysis. This theory is illustrated by ethnographic and sociometric data drawn from a study comparing usage of traditional and computerized imaging devices in two radiology…

Decoupling capabilities of split-loop resonator structure for 7 Tesla MRI surface array coils

NASA Astrophysics Data System (ADS)

Hurshkainen, A.; Kurdjumov, S.; Simovski, C.; Glybovski, S.; Melchakova, I.; van den Berg, C. A. T.; Raaijmakers, A.; Belov, P.

2017-09-01

In this work we studied electromagnetic properties of one-dimentional periodic structures composed of split-loop res-onators (SLRs) and investigated their capabilities in decoupling of two dipole antennas for full-body magnetic resonance imaging (MRI). Two different finite structures comprising a single-SLR and a double-SLR constitutive elements were studied. Numerical simulations of the structures were performed to evaluate their decoupling capabilities. As it was demonstrated two dipole antennas equipped with either a single or a double-SLR structure exhibit high isolation even for an electrically short distance between the dipoles. Double-SLR structure while dramatically improving isolation of the dipoles keeps the field created by each of the decoupled dipoles comparable with one of a single dipole inside the target area.

Residue-level global and local ensemble-ensemble comparisons of protein domains.

PubMed

Clark, Sarah A; Tronrud, Dale E; Karplus, P Andrew

2015-09-01

Many methods of protein structure generation such as NMR-based solution structure determination and template-based modeling do not produce a single model, but an ensemble of models consistent with the available information. Current strategies for comparing ensembles lose information because they use only a single representative structure. Here, we describe the ENSEMBLATOR and its novel strategy to directly compare two ensembles containing the same atoms to identify significant global and local backbone differences between them on per-atom and per-residue levels, respectively. The ENSEMBLATOR has four components: eePREP (ee for ensemble-ensemble), which selects atoms common to all models; eeCORE, which identifies atoms belonging to a cutoff-distance dependent common core; eeGLOBAL, which globally superimposes all models using the defined core atoms and calculates for each atom the two intraensemble variations, the interensemble variation, and the closest approach of members of the two ensembles; and eeLOCAL, which performs a local overlay of each dipeptide and, using a novel measure of local backbone similarity, reports the same four variations as eeGLOBAL. The combination of eeGLOBAL and eeLOCAL analyses identifies the most significant differences between ensembles. We illustrate the ENSEMBLATOR's capabilities by showing how using it to analyze NMR ensembles and to compare NMR ensembles with crystal structures provides novel insights compared to published studies. One of these studies leads us to suggest that a "consistency check" of NMR-derived ensembles may be a useful analysis step for NMR-based structure determinations in general. The ENSEMBLATOR 1.0 is available as a first generation tool to carry out ensemble-ensemble comparisons. © 2015 The Protein Society.

Residue-level global and local ensemble-ensemble comparisons of protein domains

PubMed Central

Clark, Sarah A; Tronrud, Dale E; Andrew Karplus, P

2015-01-01

Many methods of protein structure generation such as NMR-based solution structure determination and template-based modeling do not produce a single model, but an ensemble of models consistent with the available information. Current strategies for comparing ensembles lose information because they use only a single representative structure. Here, we describe the ENSEMBLATOR and its novel strategy to directly compare two ensembles containing the same atoms to identify significant global and local backbone differences between them on per-atom and per-residue levels, respectively. The ENSEMBLATOR has four components: eePREP (ee for ensemble-ensemble), which selects atoms common to all models; eeCORE, which identifies atoms belonging to a cutoff-distance dependent common core; eeGLOBAL, which globally superimposes all models using the defined core atoms and calculates for each atom the two intraensemble variations, the interensemble variation, and the closest approach of members of the two ensembles; and eeLOCAL, which performs a local overlay of each dipeptide and, using a novel measure of local backbone similarity, reports the same four variations as eeGLOBAL. The combination of eeGLOBAL and eeLOCAL analyses identifies the most significant differences between ensembles. We illustrate the ENSEMBLATOR's capabilities by showing how using it to analyze NMR ensembles and to compare NMR ensembles with crystal structures provides novel insights compared to published studies. One of these studies leads us to suggest that a “consistency check” of NMR-derived ensembles may be a useful analysis step for NMR-based structure determinations in general. The ENSEMBLATOR 1.0 is available as a first generation tool to carry out ensemble-ensemble comparisons. PMID:26032515

Chapter C. The Loma Prieta, California, Earthquake of October 17, 1989 - Building Structures

USGS Publications Warehouse

Çelebi, Mehmet

1998-01-01

Several approaches are used to assess the performance of the built environment following an earthquake -- preliminary damage surveys conducted by professionals, detailed studies of individual structures, and statistical analyses of groups of structures. Reports of damage that are issued by many organizations immediately following an earthquake play a key role in directing subsequent detailed investigations. Detailed studies of individual structures and statistical analyses of groups of structures may be motivated by particularly good or bad performance during an earthquake. Beyond this, practicing engineers typically perform stress analyses to assess the performance of a particular structure to vibrational levels experienced during an earthquake. The levels may be determined from recorded or estimated ground motions; actual levels usually differ from design levels. If a structure has seismic instrumentation to record response data, the estimated and recorded response and behavior of the structure can be compared.

Structural Analysis of Chemokine Receptor–Ligand Interactions

PubMed Central

2017-01-01

This review focuses on the construction and application of structural chemokine receptor models for the elucidation of molecular determinants of chemokine receptor modulation and the structure-based discovery and design of chemokine receptor ligands. A comparative analysis of ligand binding pockets in chemokine receptors is presented, including a detailed description of the CXCR4, CCR2, CCR5, CCR9, and US28 X-ray structures, and their implication for modeling molecular interactions of chemokine receptors with small-molecule ligands, peptide ligands, and large antibodies and chemokines. These studies demonstrate how the integration of new structural information on chemokine receptors with extensive structure–activity relationship and site-directed mutagenesis data facilitates the prediction of the structure of chemokine receptor–ligand complexes that have not been crystallized. Finally, a review of structure-based ligand discovery and design studies based on chemokine receptor crystal structures and homology models illustrates the possibilities and challenges to find novel ligands for chemokine receptors. PMID:28165741

Multistep modeling (MSM) of biomolecular structure application to the A-G mispair in the B-DNA environment

NASA Technical Reports Server (NTRS)

Srinivasan, S.; Raghunathan, G.; Shibata, M.; Rein, R.

1986-01-01

A multistep modeling procedure has been evolved to study the structural changes introduced by lesions in DNA. We report here the change in the structure of regular B-DNA geometry due to the incorporation of Ganti-Aanti mispair in place of a regular G-C pair, preserving the helix continuity. The energetics of the structure so obtained is compared with the Ganti-Asyn configuration under similar constrained conditions. We present the methodology adopted and discuss the results.

A Comparative Study of Multi-material Data Structures for Computational Physics Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garimella, Rao Veerabhadra; Robey, Robert W.

The data structures used to represent the multi-material state of a computational physics application can have a drastic impact on the performance of the application. We look at efficient data structures for sparse applications where there may be many materials, but only one or few in most computational cells. We develop simple performance models for use in selecting possible data structures and programming patterns. We verify the analytic models of performance through a small test program of the representative cases.

Comparative studies of efficiency droop in polar and non-polar InGaN quantum wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davies, M. J.; Dawson, P.; Hammersley, S.

We report on a comparative study of efficiency droop in polar and non-polar InGaN quantum well structures at T = 10 K. To ensure that the experiments were carried out with identical carrier densities for any particular excitation power density, we used laser pulses of duration ∼100 fs at a repetition rate of 400 kHz. For both types of structures, efficiency droop was observed to occur for carrier densities of above 7 × 10{sup 11 }cm{sup −2 }pulse{sup −1} per quantum well; also both structures exhibited similar spectral broadening in the droop regime. These results show that efficiency droop is intrinsic in InGaN quantum wells, whether polar or non-polar,more » and is a function, specifically, of carrier density.« less

Comparative study on structural and optical properties of CdS films fabricated by three different low-cost techniques

NASA Astrophysics Data System (ADS)

Ravichandran, K.; Philominathan, P.

2009-03-01

Highly crystalline and transparent cadmium sulphide films were fabricated at relatively low temperature by employing an inexpensive, simplified spray technique using perfume atomizer (generally used for cosmetics). The structural, surface morphological and optical properties of the films were studied and compared with that prepared by conventional spray pyrolysis using air as carrier gas and chemical bath deposition. The films deposited by the simplified spray have preferred orientation along (1 0 1) plane. The lattice parameters were calculated as a = 4.138 Å and c = 6.718 Å which are well agreed with that obtained from the other two techniques and also with the standard data. The optical transmittance in the visible range and the optical band gap were found as 85% and 2.43 eV, respectively. The structural and optical properties of the films fabricated by the simplified spray are found to be desirable for opto-electronic applications.

Comparative structural analysis of cytidine, ethenocytidine and their protonated salts III. 1H, 13C and 15N NMR studies at natural isotope abundance.

PubMed Central

Kozerski, L; Sierzputowska-Gracz, H; Krzyzosiak, W; Bratek-Wiewiórowska, M; Jaskólski, M; Wiewiórowski, M

1984-01-01

The 1H, 13C, 15N NMR spectra of cytidine /Cyd/, ethenocytidine /epsilon Cyd/ and their hydrochlorides /Cyd X HC1/ and /epsilon Cyd X HC1/ have been analysed to compare structural differences observed in solution with those existing in the crystalline state. The effects of ethenobridging and protonation of the hertero-aromatic base on the intramolecular stereochemistry, intermolecular interactions and electronic structure of the whole molecule are discussed on the basis of the NMR studies in DMSO solutions. Particular interest is devoted to the discussion of the conformation of the ribose ring, the presence of the intramolecular C-5'-0...H-6-C hydrogen bond, unambiguous assignment of the site of protonation, the mechanism of the 5C-H deuterium exchange in Cyd X HC1, and the intermolecular interactions in solution. PMID:6701098

Assessing the Universal Structure of Personality in Early Adolescence: The NEO-PI-R and NEO-PI-3 in 24 Cultures

PubMed Central

De Fruyt, Filip; De Bolle, Marleen; McCrae, Robert R.; Terracciano, Antonio; Costa, Paul T.

2010-01-01

The structure and psychometric characteristics of the NEO-PI-3, a more readable version of the NEO-PI-R, are examined and compared with NEO-PI-R characteristics using data from college student observer ratings of 5,109 adolescents aged 12 to 17 from 24 cultures. Replacement items in the PI-3 showed on average stronger item/total correlations and slightly improved facet reliabilities compared with the NEO-PI-R in both English- and non-English-speaking samples. NEO-PI-3 replacement items did not substantially affect scale means compared with the original scales. Analyses across and within cultures confirmed the intended factor structure of both versions when used to describe young adolescents. We discuss implications of these cross-cultural findings for the advancement of studies in adolescence and personality development across the lifespan. PMID:19419953

Inflight Characterization of the Cassini Spacecraft Propellant Slosh and Structural Frequencies

NASA Technical Reports Server (NTRS)

Lee, Allan Y.; Stupik, Joan

2015-01-01

While there has been extensive theoretical and analytical research regarding the characterization of spacecraft propellant slosh and structural frequencies, there have been limited studies to compare the analytical predictions with measured flight data. This paper uses flight telemetry from the Cassini spacecraft to get estimates of high-g propellant slosh frequencies and the magnetometer boom frequency characteristics, and compares these values with those predicted by theoretical works. Most Cassini attitude control data are available at a telemetry frequency of 0.5 Hz. Moreover, liquid sloshing is attenuated by propellant management device and attitude controllers. Identification of slosh and structural frequency are made on a best-effort basis. This paper reviews the analytical approaches that were used to predict the Cassini propellant slosh frequencies. The predicted frequencies are then compared with those estimated using telemetry from selected Cassini burns where propellant sloshing was observed (such as the Saturn Orbit Insertion burn).

Assessing the universal structure of personality in early adolescence: The NEO-PI-R and NEO-PI-3 in 24 cultures.

PubMed

De Fruyt, Filip; De Bolle, Marleen; McCrae, Robert R; Terracciano, Antonio; Costa, Paul T

2009-09-01

The structure and psychometric characteristics of the NEO Personality Inventory-3 (NEO-PI-3), a more readable version of the Revised NEO Personality Inventory (NEO-PI-R), are examined and compared with NEO-PI-R characteristics using data from college student observer ratings of 5,109 adolescents aged 12 to 17 years from 24 cultures. Replacement items in the PI-3 showed on average stronger item-total correlations and slightly improved facet reliabilities compared with the NEO-PI-R in both English- and non-English-speaking samples. NEO-PI-3 replacement items did not substantially affect scale means compared with the original scales. Analyses across and within cultures confirmed the intended factor structure of both versions when used to describe young adolescents. The authors discuss implications of these cross-cultural findings for the advancement of studies in adolescence and personality development across the lifespan.

Comorbidity and ventricular and vascular structure and function in heart failure with preserved ejection fraction: a community-based study.

PubMed

Mohammed, Selma F; Borlaug, Barry A; Roger, Véronique L; Mirzoyev, Sultan A; Rodeheffer, Richard J; Chirinos, Julio A; Redfield, Margaret M

2012-11-01

Patients with heart failure and preserved ejection fraction (HFpEF) display increased adiposity and multiple comorbidities, factors that in themselves may influence cardiovascular structure and function. This has sparked debate as to whether HFpEF represents a distinct disease or an amalgamation of comorbidities. We hypothesized that fundamental cardiovascular structural and functional alterations are characteristic of HFpEF, even after accounting for body size and comorbidities. Comorbidity-adjusted cardiovascular structural and functional parameters scaled to independently generated and age-appropriate allometric powers were compared in community-based cohorts of HFpEF patients (n=386) and age/sex-matched healthy n=193 and hypertensive, n=386 controls. Within HFpEF patients, body size and concomitant comorbidity-adjusted cardiovascular structural and functional parameters and survival were compared in those with and without individual comorbidities. Among HFpEF patients, comorbidities (obesity, anemia, diabetes mellitus, and renal dysfunction) were each associated with unique clinical, structural, functional, and prognostic profiles. However, after accounting for age, sex, body size, and comorbidities, greater concentric hypertrophy, atrial enlargement and systolic, diastolic, and vascular dysfunction were consistently observed in HFpEF compared with age/sex-matched normotensive and hypertensive. Comorbidities influence ventricular-vascular properties and outcomes in HFpEF, yet fundamental disease-specific changes in cardiovascular structure and function underlie this disorder. These data support the search for mechanistically targeted therapies in this disease.

THE LANGUAGE OF ELEMENTARY SCHOOL CHILDREN--ITS RELATIONSHIP TO THE LANGUAGE OF READING TEXTBOOKS AND THE QUALITY OF READING OF SELECTED CHILDREN.

ERIC Educational Resources Information Center

STRICKLAND, RUTH G.

THIS STUDY WAS DESIGNED TO (1) ANALYZE THE ORAL LANGUAGE STRUCTURE OF FIRST- THROUGH SIXTH-GRADE CHILDREN, (2) COMPARE THAT STRUCTURE WITH THE LANGUAGE STRUCTURE IN BOOKS BY WHICH CHILDREN ARE TAUGHT TO READ, AND (3) ASCERTAIN, AT THE SECOND-GRADE LEVEL, THE INFLUENCE OF ANY DETERMINED DIFFERENCES ON THE QUALITY OF READING, READING INTERPRETATION,…

When structure affects function--the need for partial volume effect correction in functional and resting state magnetic resonance imaging studies.

PubMed

Dukart, Juergen; Bertolino, Alessandro

2014-01-01

Both functional and also more recently resting state magnetic resonance imaging have become established tools to investigate functional brain networks. Most studies use these tools to compare different populations without controlling for potential differences in underlying brain structure which might affect the functional measurements of interest. Here, we adapt a simulation approach combined with evaluation of real resting state magnetic resonance imaging data to investigate the potential impact of partial volume effects on established functional and resting state magnetic resonance imaging analyses. We demonstrate that differences in the underlying structure lead to a significant increase in detected functional differences in both types of analyses. Largest increases in functional differences are observed for highest signal-to-noise ratios and when signal with the lowest amount of partial volume effects is compared to any other partial volume effect constellation. In real data, structural information explains about 25% of within-subject variance observed in degree centrality--an established resting state connectivity measurement. Controlling this measurement for structural information can substantially alter correlational maps obtained in group analyses. Our results question current approaches of evaluating these measurements in diseased population with known structural changes without controlling for potential differences in these measurements.

Comparative study of particle structure evolution during water sorption: skim and whole milk powders.

PubMed

Murrieta-Pazos, I; Gaiani, C; Galet, L; Cuq, B; Desobry, S; Scher, J

2011-10-01

Surface composition of dairy powders influences significantly a quantity of functional properties such as rehydration, caking, agglomeration. Nevertheless, the kinetic of water uptake by the powders was never directly related to the structure and the composition of the surface. In this work, the effect of relative humidity on the structural reorganization of two types of dairy powder was studied. The water-powder interaction for industrial whole milk powder, and skim milk powder was studied using dynamic vapor sorption. The water sorption isotherms were fitted with a Brunner-Emmet-Teller model and each stage of the sorption curve was analyzed with a Fickian diffusion. The water content in the monolayer predicted for each powder and the moisture diffusivity calculated were discussed and compared. Concurrently, powders microstructure and powders surface under variable relative humidity were assessed by X-ray photoelectron spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray and atomic force microscopy. A correlation between the data obtained from the sorption isotherms and the modifications of structure allowed us to conclude that powder microstructure and chemical state of the components could play an important role in determining the water diffusivity. Copyright © 2011 Elsevier B.V. All rights reserved.

Characterization of Gastric Microbiota in Twins.

PubMed

Dong, Quanjiang; Xin, Yongning; Wang, Lili; Meng, Xinying; Yu, Xinjuan; Lu, Linlin; Xuan, Shiying

2017-02-01

Contribution of host genetic backgrounds in the development of gastric microbiota has not been clearly defined. This study was aimed to characterize the biodiversity, structure and composition of gastric microbiota among twins. A total of four pairs of twins and eight unrelated individuals were enrolled in the study. Antral biopsies were obtained during endoscopy. The bacterial 16S rRNA gene was amplified and pyrosequenced. Sequences were analyzed for the composition, structure, and α and β diversities of gastric microbiota. Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, and Fusobacteria were the most predominant phyla of gastric microbiota. Each individual, twins as well as unrelated individuals, harbored a microbiota of distinct composition. There was no evidence of additional similarity in the richness and evenness of gastric microbiota among co-twins as compared to unrelated individuals. Calculations of θ YC and PCoA demonstrated that the structure similarity of gastric microbial community between co-twins did not increase compared to unrelated individuals. In contrast, the structure of microbiota was altered enormously by Helicobacter pylori infection. These results suggest that host genetic backgrounds had little effect in shaping the gastric microbiota. This property of gastric microbiota could facilitate the studies discerning the role of microbiota from genetic grounds in the pathogenesis.

Effect of two imidazolium derivatives of ionic liquids on the structure and activity of adenosine deaminase.

PubMed

Ajloo, Davood; Sangian, Masoomeh; Ghadamgahi, Maryam; Evini, Mina; Saboury, Ali Akbar

2013-04-01

The effect of two ionic liquids, 1-allyl 3-methyl-imidazolium (IL1) and 1-octhyl 3-methyl-imidozolium chlorides (IL2), on the structure and activity of adenosine deaminase (ADA) were described by UV-vis and fluorescence spectrophotometry in phosphate buffer and results were compared with docking and molecular dynamics (MD) simulation studies. All results showed that inhibition of activity and reduction of enzyme tertiary structure are more for octhyl than allyl derivative due to the more hydrophobic property of it. Finally structure parameters obtained from MD simulation showed that ionic liquid reduces intermolecular hydrogen bond and unfold enzyme structure. Calculation results are in good agreement with spectrophotometric studies. Copyright © 2013 Elsevier B.V. All rights reserved.

Structure factor and radial distribution function of some liquid lanthanides using charged hard sphere

NASA Astrophysics Data System (ADS)

Patel, H. P.; Sonvane, Y. A.; Thakor, P. B.

2017-05-01

The structure factor S(q) and radial distribution function g(r) play vital role to study the various structural properties like electronic, dynamic, magnetic etc. The present paper deals with the structural studies of foresaid properties using our newly constructed parameter free model potential with the Charged Hard Sphere (CHS) approximation. The local field correction due to Sarkar et al. is used to incorporate exchange and correlation among the conduction electrons in dielectric screening. Here we report the S(q) and g(r) for some liquid lanthanides viz: La, Ce, Pr, Nd and Eu. Present computed results are compared with the available experimental data. Lastly we found that our parameter free model potential successfully explains the structural propertiesof4fliquidlanthanides.

Replication Research in Comparative Genre Analysis in English for Academic Purposes

ERIC Educational Resources Information Center

Basturkmen, Helen

2014-01-01

In recent years a number of comparative studies based on an established approach to genre analysis have been published in the English for Academic Purposes (EAP) literature. Studies in this emerging strand of research typically aim to identify how the rhetorical structure of a particular genre (a text type) or part of a genre may vary across…

Neither Orthodoxy nor Randomness: Differing Logics of Conducting Comparative and International Studies in Education

ERIC Educational Resources Information Center

Schriewer, Jürgen

2014-01-01

The issue of the presumed "identity" of Comparative Education as a field of study or a discipline has been discussed for decades. Yet what remains open to question is a kind of systematic structure that provides the basic principles for a coherent exposition of the field. After conceptualising and rejecting almost a dozen possible…

Selective Laser Melting: a regular unit cell approach for the manufacture of porous, titanium, bone in-growth constructs, suitable for orthopedic applications.

PubMed

Mullen, Lewis; Stamp, Robin C; Brooks, Wesley K; Jones, Eric; Sutcliffe, Christopher J

2009-05-01

In this study, a novel porous titanium structure for the purpose of bone in-growth has been designed, manufactured and evaluated. The structure was produced by Selective Laser Melting (SLM); a rapid manufacturing process capable of producing highly intricate, functionally graded parts. The technique described utilizes an approach based on a defined regular unit cell to design and produce structures with a large range of both physical and mechanical properties. These properties can be tailored to suit specific requirements; in particular, functionally graded structures with bone in-growth surfaces exhibiting properties comparable to those of human bone have been manufactured. The structures were manufactured and characterized by unit cell size, strand diameter, porosity, and compression strength. They exhibited a porosity (10-95%) dependant compression strength (0.5-350 Mpa) comparable to the typical naturally occurring range. It is also demonstrated that optimized structures have been produced that possesses ideal qualities for bone in-growth applications and that these structures can be applied in the production of orthopedic devices. (c) 2008 Wiley Periodicals, Inc.

Neurostructural correlates of two subtypes of specific phobia: a voxel-based morphometry study.

PubMed

Hilbert, Kevin; Evens, Ricarda; Maslowski, Nina Isabel; Wittchen, Hans-Ulrich; Lueken, Ulrike

2015-02-28

The animal and blood-injection-injury (BII) subtypes of specific phobia are both characterized by subjective fear but distinct autonomic reactions to threat. Previous functional neuroimaging studies have related these characteristic responses to shared and non-shared neural underpinnings. However, no comparative structural data are available. This study aims to fill this gap by comparing the two subtypes and also comparing them with a non-phobic control group. Gray and white matter data of 33 snake phobia subjects (SP), 26 dental phobia subjects (DP), and 37 healthy control (HC) subjects were analyzed with voxel-based morphometry. Especially DP differed from HC and SP by showing significantly increased grey matter volumes in widespread areas including the right subgenual anterior cingulate gyrus, left insula, left orbitofrontal and left prefrontal (PFC) cortices. In addition, white matter volume was significantly increased in the left PFC in DP compared with SP. These results are in line with functional changes observed in dental phobia and point toward those brain circuits associated with emotional processing and regulation. Future studies should aim to further delineate functional and structural connectivity alterations in specific phobia. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

A preliminary study of extended magnetic field structures in the ionosphere

NASA Technical Reports Server (NTRS)

Sullivan, James D.; Lane, Barton G.; Post, Richard S.

1987-01-01

Several plasma phenomena which are to be expected around a magnet in LEO were identified and analyzed qualitatively. The ASTROMAG cusp magnet will create an extended field whose strength drops to the ambient level over a scale length of approx. 15 m; the combined field has a complex topology with ring nulls and open and closed field lines. The entire configuration is moving through the partially ionized F-layer of the ionosphere at a speed slow compared to the local Alfven speed but fast compared to the ion sound speed. The ambient plasma crosses the extended field structure in a time short compared to the ion Larmor period yet long relative to the electron Larmor period. Thus, electrons behave as a magnetized fluid while ions move ballistically until reflected from higher fields near the cusp. Since the Debye length is short compared to the field scale length, an electrostatic shock-like structure forms to equilibrate the flows and achieve quasi-neutrality. The ambient plasma will be excluded from a cavity near the magnet. The size and nature of the strong interaction region in which the magnet significantly perturbs the ambient flow were determined by studying ion orbits numerically. Lecture viewgraphs summarizing these results are presented.

Comparative analyses of structural features and scaffold diversity for purchasable compound libraries.

PubMed

Shang, Jun; Sun, Huiyong; Liu, Hui; Chen, Fu; Tian, Sheng; Pan, Peichen; Li, Dan; Kong, Dexin; Hou, Tingjun

2017-04-21

Large purchasable screening libraries of small molecules afforded by commercial vendors are indispensable sources for virtual screening (VS). Selecting an optimal screening library for a specific VS campaign is quite important to improve the success rates and avoid wasting resources in later experimental phases. Analysis of the structural features and molecular diversity for different screening libraries can provide valuable information to the decision making process when selecting screening libraries for VS. In this study, the structural features and scaffold diversity of eleven purchasable screening libraries and Traditional Chinese Medicine Compound Database (TCMCD) were analyzed and compared. Their scaffold diversity represented by the Murcko frameworks and Level 1 scaffolds was characterized by the scaffold counts and cumulative scaffold frequency plots, and visualized by Tree Maps and SAR Maps. The analysis demonstrates that, based on the standardized subsets with similar molecular weight distributions, Chembridge, ChemicalBlock, Mucle, TCMCD and VitasM are more structurally diverse than the others. Compared with all purchasable screening libraries, TCMCD has the highest structural complexity indeed but more conservative molecular scaffolds. Moreover, we found that some representative scaffolds were important components of drug candidates against different drug targets, such as kinases and guanosine-binding protein coupled receptors, and therefore the molecules containing pharmacologically important scaffolds found in screening libraries might be potential inhibitors against the relevant targets. This study may provide valuable perspective on which purchasable compound libraries are better for you to screen. Graphical abstract Selecting diverse compound libraries with scaffold analyses.

A comparative experimental and quantum chemical study on monomeric and dimeric structures of 3,5-dibromoanthranilic acid.

PubMed

Karabacak, Mehmet; Cinar, Mehmet

2012-10-01

This study presents the structural and spectroscopic characterization of 3,5-dibromoanthranilic acid with help of experimental techniques (FT-IR, FT-Raman, UV, NMR) and quantum chemical calculations. The vibrational spectra of title compound were recorded in solid state with FT-IR and FT-Raman in the range of 4000-400 and 4000-50 cm(-1), respectively. The vibrational frequencies were also computed using B3LYP method of DFT with 6-311++G(d,p) basis set. The fundamental assignments were done on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. The (1)H, (13)C and DEPT NMR spectra were recorded in DMSO solution and calculated by gauge-invariant atomic orbitals (GIAO) method. The UV absorption spectra of the compound were recorded in the range of 200-400 nm in ethanol, water and DMSO solutions. Solvent effects were calculated using time-dependent density functional theory and CIS method. The ground state geometrical structure of compound was predicted by B3LYP method and compared with the crystallographic structure of similar compounds. All calculations were made for monomeric and dimeric structure of compound. Moreover, molecular electrostatic potential (MEP) and thermodynamic properties were performed. Mulliken atomic charges of neutral and anionic form of the molecule were computed and compared with anthranilic acid. Copyright © 2012 Elsevier B.V. All rights reserved.

Integrated passive/active vibration absorber for multi-story buildings

NASA Technical Reports Server (NTRS)

Lee-Glauser, Gina J.; Ahmadi, Goodarz; Horta, Lucas G.

1995-01-01

Passive isolator, active vibration absorber, and an integrated passive/active (hybrid) control are studied for their effectiveness in reducing structural vibration under seismic excitations. For the passive isolator, a laminated rubber bearing base isolator which has been studied and used extensively by researchers and seismic designers is considered. An active vibration absorber concept, which can provide guaranteed closed-loop stability with minimum knowledge of the controlled system, is used to reduce the passive isolator displacement and to suppress the top floor vibration. A three-story building model is used for the numerical simulation. The performance of an active vibration absorber and a hybrid vibration controller in reducing peak structural responses is compared with the passively isolated structural response and with absence of vibration control systems under the N00W component of El Centro 1940 and N90W component of the Mexico City earthquake excitation records. The results show that the integrated passive/active vibration control system is most effective in suppressing the peak structural acceleration for the El Centro 1940 earthquake when compared with the passive or active vibration absorber alone. The active vibration absorber, however, is the only system that suppresses the peak acceleration of the structure for the Mexico City 1985 earthquake.

Origin of structural analogies and differences between the atomic structures of GeSe4 and GeS4 glasses: A first principles study.

PubMed

Bouzid, Assil; Le Roux, Sébastien; Ori, Guido; Boero, Mauro; Massobrio, Carlo

2015-07-21

First-principles molecular dynamics simulations based on density functional theory are employed for a comparative study of structural and bonding properties of two stoichiometrically identical chalcogenide glasses, GeSe4 and GeS4. Two periodic cells of 120 and 480 atoms are adopted. Both glasses feature a coexistence of Ge-centered tetrahedra and Se(S) homopolar connections. Results obtained for N = 480 indicate substantial differences at the level of the Se(S) environment, since Ge-Se-Se connections are more frequent than the corresponding Ge-S-S ones. The presence of a more prominent first sharp diffraction peak in the total neutron structure factor of glassy GeS4 is rationalized in terms of a higher number of large size rings, accounting for extended Ge-Se correlations. Both the electronic density of states and appropriate electronic localization tools provide evidence of a higher ionic character of Ge-S bonds when compared to Ge-Se bonds. An interesting byproduct of these investigations is the occurrence of discernible size effects that affect structural motifs involving next nearest neighbor distances, when 120 or 480 atoms are used.

Hierarchical structural health monitoring system combining a fiber optic spinal cord network and distributed nerve cell devices

NASA Astrophysics Data System (ADS)

Minakuchi, Shu; Tsukamoto, Haruka; Takeda, Nobuo

2009-03-01

This study proposes novel hierarchical sensing concept for detecting damages in composite structures. In the hierarchical system, numerous three-dimensionally structured sensor devices are distributed throughout the whole structural area and connected with the optical fiber network through transducing mechanisms. The distributed "sensory nerve cell" devices detect the damage, and the fiber optic "spinal cord" network gathers damage signals and transmits the information to a measuring instrument. This study began by discussing the basic concept of the hierarchical sensing system thorough comparison with existing fiber optic based systems and nerve systems in the animal kingdom. Then, in order to validate the proposed sensing concept, impact damage detection system for the composite structure was proposed. The sensor devices were developed based on Comparative Vacuum Monitoring (CVM) system and the Brillouin based distributed strain sensing was utilized to gather the damage signals from the distributed devices. Finally a verification test was conducted using prototype devices. Occurrence of barely visible impact damage was successfully detected and it was clearly indicated that the hierarchical system has better repairability, higher robustness, and wider monitorable area compared to existing systems utilizing embedded optical fiber sensors.

SoMIR framework for designing high-NDBP photonic crystal waveguides.

PubMed

Mirjalili, Seyed Mohammad

2014-06-20

This work proposes a modularized framework for designing the structure of photonic crystal waveguides (PCWs) and reducing human involvement during the design process. The proposed framework consists of three main modules: parameters module, constraints module, and optimizer module. The first module is responsible for defining the structural parameters of a given PCW. The second module defines various limitations in order to achieve desirable optimum designs. The third module is the optimizer, in which a numerical optimization method is employed to perform optimization. As case studies, two new structures called Ellipse PCW (EPCW) and Hypoellipse PCW (HPCW) with different shape of holes in each row are proposed and optimized by the framework. The calculation results show that the proposed framework is able to successfully optimize the structures of the new EPCW and HPCW. In addition, the results demonstrate the applicability of the proposed framework for optimizing different PCWs. The results of the comparative study show that the optimized EPCW and HPCW provide 18% and 9% significant improvements in normalized delay-bandwidth product (NDBP), respectively, compared to the ring-shape-hole PCW, which has the highest NDBP in the literature. Finally, the simulations of pulse propagation confirm the manufacturing feasibility of both optimized structures.

REMOVAL AND CONTAINMENT OF LEAD-BASED PAINT VIA NEEDLE SCALERS

EPA Science Inventory

This report describes a comparative technical and economic evaluation of using a dustless needlegun system versus a conventional abrasive grit blasting system in the removal of lead-based paint from steel structures. The objective of the study was to comparatively analyze the ope...

Comparing Faculty Perceptions of Sustainability Teaching at Two US Universities

ERIC Educational Resources Information Center

Tziganuk, Ashlee; Gliedt, Travis

2017-01-01

Purpose: This study aims to examine and compare faculty perceptions of the process of institutionalizing sustainability, developing sustainability pedagogy and activating key sustainability competencies between the University of Oklahoma (OU) and Arizona State University (ASU). Design/methodology/approach: Semi-structured interviews were conducted…

Conformational structures of a decapeptide validated by first principles calculations and cold ion spectroscopy.

PubMed

Roy, Tapta Kanchan; Kopysov, Vladimir; Nagornova, Natalia S; Rizzo, Thomas R; Boyarkin, Oleg V; Gerber, R Benny

2015-05-18

Calculated structures of the two most stable conformers of a protonated decapeptide gramicidin S in the gas phase have been validated by comparing the vibrational spectra, calculated from first- principles and measured in a wide spectral range using infrared (IR)-UV double resonance cold ion spectroscopy. All the 522 vibrational modes of each conformer were calculated quantum mechanically and compared with the experiment without any recourse to an empirical scaling. The study demonstrates that first-principles calculations, when accounting for vibrational anharmonicity, can reproduce high-resolution experimental spectra well enough for validating structures of molecules as large as of 200 atoms. The validated accurate structures of the peptide may serve as templates for in silico drug design and absolute calibration of ion mobility measurements. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effects of lithium and anticonvulsants on brain structure in bipolar disorder.

PubMed

Germaná, C; Kempton, M J; Sarnicola, A; Christodoulou, T; Haldane, M; Hadjulis, M; Girardi, P; Tatarelli, R; Frangou, S

2010-12-01

To investigate the effect of lithium, anticonvulsants and antipsychotics on brain structure in bipolar disorder (BD). A cross-sectional structural brain magnetic resonance imaging study of 74 remitted patients with BD, aged 18-65, who were receiving long-term prophylactic treatment with lithium or anticonvulsants or antipsychotics. Global and regional grey matter, white matter, and cerebrospinal fluid volumes were compared between treatment groups. Grey matter in the subgenual anterior cingulate gyrus on the right (extending into the hypothalamus) and in the postcentral gyrus, the hippocampus/amygdale complex and the insula on the left was greater in BD patients on lithium treatment compared to all other treatment groups. Lithium treatment in BD has a significant effect on brain structure particularly in limbic/paralimbic regions associated with emotional processing. © 2010 John Wiley & Sons A/S.

Fe Oxides on Ag Surfaces: Structure and Reactivity

DOE PAGES

Shipilin, M.; Lundgren, E.; Gustafson, J.; ...

2016-09-09

One layer thick iron oxide films are attractive from both applied and fundamental science perspectives. The structural and chemical properties of these systems can be tuned by changing the substrate, making them promising materials for heterogeneous catalysis. In the present work, we investigate the structure of FeO(111) monolayer films grown on Ag(100) and Ag(111) substrates by means of microscopy and diffraction techniques and compare it with the structure of FeO(111) grown on other substrates reported in literature. We also study the NO adsorption properties of FeO(111)/Ag(100) and FeO(111)/Ag(111) systems utilizing different spectroscopic techniques. Finally, we discuss similarities and differences inmore » the data obtained from adsorption experiments and compare it with previous results for FeO(111)/Pt(111).« less

Fe Oxides on Ag Surfaces: Structure and Reactivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shipilin, M.; Lundgren, E.; Gustafson, J.

One layer thick iron oxide films are attractive from both applied and fundamental science perspectives. The structural and chemical properties of these systems can be tuned by changing the substrate, making them promising materials for heterogeneous catalysis. In the present work, we investigate the structure of FeO(111) monolayer films grown on Ag(100) and Ag(111) substrates by means of microscopy and diffraction techniques and compare it with the structure of FeO(111) grown on other substrates reported in literature. We also study the NO adsorption properties of FeO(111)/Ag(100) and FeO(111)/Ag(111) systems utilizing different spectroscopic techniques. Finally, we discuss similarities and differences inmore » the data obtained from adsorption experiments and compare it with previous results for FeO(111)/Pt(111).« less

Association between brain structure and phenotypic characteristics in pedophilia.

PubMed

Poeppl, Timm B; Nitschke, Joachim; Santtila, Pekka; Schecklmann, Martin; Langguth, Berthold; Greenlee, Mark W; Osterheider, Michael; Mokros, Andreas

2013-05-01

Studies applying structural neuroimaging to pedophiles are scarce and have shown conflicting results. Although first findings suggested reduced volume of the amygdala, pronounced gray matter decreases in frontal regions were observed in another group of pedophilic offenders. When compared to non-sexual offenders instead of community controls, pedophiles revealed deficiencies in white matter only. The present study sought to test the hypotheses of structurally compromised prefrontal and limbic networks and whether structural brain abnormalities are related to phenotypic characteristics in pedophiles. We compared gray matter volume of male pedophilic offenders and non-sexual offenders from high-security forensic hospitals using voxel-based morphometry in cross-sectional and correlational whole-brain analyses. The significance threshold was set to p < .05, corrected for multiple comparisons. Compared to controls, pedophiles exhibited a volume reduction of the right amygdala (small volume corrected). Within the pedophilic group, pedosexual interest and sexual recidivism were correlated with gray matter decrease in the left dorsolateral prefrontal cortex (r = -.64) and insular cortex (r = -.45). Lower age of victims was strongly associated with gray matter reductions in the orbitofrontal cortex (r = .98) and angular gyri bilaterally (r = .70 and r = .93). Our findings of specifically impaired neural networks being related to certain phenotypic characteristics might account for the heterogeneous results in previous neuroimaging studies of pedophilia. The neuroanatomical abnormalities in pedophilia seem to be of a dimensional rather than a categorical nature, supporting the notion of a multifaceted disorder. Copyright © 2013 Elsevier Ltd. All rights reserved.

Theoretical calculations of structural, electronic, and elastic properties of CdSe1-x Te x : A first principles study

NASA Astrophysics Data System (ADS)

M, Shakil; Muhammad, Zafar; Shabbir, Ahmed; Muhammad Raza-ur-rehman, Hashmi; M, A. Choudhary; T, Iqbal

2016-07-01

The plane wave pseudo-potential method was used to investigate the structural, electronic, and elastic properties of CdSe1-x Te x in the zinc blende phase. It is observed that the electronic properties are improved considerably by using LDA+U as compared to the LDA approach. The calculated lattice constants and bulk moduli are also comparable to the experimental results. The cohesive energies for pure CdSe and CdTe binary and their mixed alloys are calculated. The second-order elastic constants are also calculated by the Lagrangian theory of elasticity. The elastic properties show that the studied material has a ductile nature.

Exploration of freely available web-interfaces for comparative homology modelling of microbial proteins

PubMed Central

Nema, Vijay; Pal, Sudhir Kumar

2013-01-01

Aim: This study was conducted to find the best suited freely available software for modelling of proteins by taking a few sample proteins. The proteins used were small to big in size with available crystal structures for the purpose of benchmarking. Key players like Phyre2, Swiss-Model, CPHmodels-3.0, Homer, (PS)2, (PS)2-V2, Modweb were used for the comparison and model generation. Results: Benchmarking process was done for four proteins, Icl, InhA, and KatG of Mycobacterium tuberculosis and RpoB of Thermus Thermophilus to get the most suited software. Parameters compared during analysis gave relatively better values for Phyre2 and Swiss-Model. Conclusion: This comparative study gave the information that Phyre2 and Swiss-Model make good models of small and large proteins as compared to other screened software. Other software was also good but is often not very efficient in providing full-length and properly folded structure. PMID:24023424

Numerical study of the effects of rotating forced downdraft in reproducing tornado-like vortices

NASA Astrophysics Data System (ADS)

Zhu, Jinwei; Cao, Shuyang; Tamura, Tetsuro; Tokyo Institute of Technology Collaboration; Tongji Univ Collaboration

2016-11-01

Appropriate physical modeling of a tornado-like vortex is a prerequisite to studying near-surface tornado structure and tornado-induced wind loads on structures. Ward-type tornado simulator modeled tornado-like flow by mounting guide vanes around the test area to provide angular momentum to converging flow. Iowa State University, USA modified the Ward-type simulator by locating guide vanes at a high position to allow vertical circulation of flow that creates a rotating forced downdraft in the process of generating a tornado. However, the characteristics of the generated vortices have not been sufficiently investigated till now. In this study, large-eddy simulations were conducted to compare the dynamic vortex structure generated with/without the effect of rotating forced downdraft. The results were also compared with other CFD and experimental results. Particular attention was devoted to the behavior of vortex wander of generated tornado-like vortices. The present study shows that the vortex center wanders more significantly when the rotating forced downdraft is introduced into the flow. The rotating forced downdraft is advantageous for modeling the rear flank downdraft phenomenon of a real tornado.

Family structure and child food insecurity.

PubMed

Miller, Daniel P; Nepomnyaschy, Lenna; Ibarra, Gabriel Lara; Garasky, Steven

2014-07-01

We examined whether food insecurity was different for children in cohabiting or repartnered families versus those in single-mother or married-parent (biological) families. We compared probabilities of child food insecurity (CFI) across different family structures in 4 national data sets: the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), the Fragile Families and Child Wellbeing Study (FFCWS), the Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K), and the Panel Study of Income Dynamics-Child Development Supplement (PSID-CDS). Unadjusted probabilities of CFI in cohabiting or repartnered families were generally higher than in married-biological-parent families and often statistically indistinguishable from those of single-mother families. However, after adjustment for sociodemographic factors, most differences between family types were attenuated and most were no longer statistically significant. Although children whose biological parents are cohabiting or whose biological mothers have repartnered have risks for food insecurity comparable to those in single-mother families, the probability of CFI does not differ by family structure when household income, family size, and maternal race, ethnicity, education, and age were held at mean levels.

Biosorption of six basic and acidic dyes on brown alga Sargassum ilicifolium: optimization, kinetic and isotherm studies.

PubMed

Tabaraki, Reza; Sadeghinejad, Negar

2017-06-01

Biosorption of Methyl Blue (MB), Fuchsin Acid (FA), Rhodamine B (RB), Methylene Blue (MEB), Bromocresol purple (BC) and Methyl Orange (MO) onto Sargassum ilicifolium was studied in a batch system. Effect of dye structure on biosorption by Sargassum ilicifolium was studied to define the correlation between chemical structure and biosorption capacity. Different dye groups such as triarylmethane (MB, FA and BC), monoazo (MO), thiazine (MEB) and xanthene (RB) were studied. At optimum experimental conditions for each dye, biosorption capacity was determined and compared. The results indicate that the chemical structure (triarylmethane, monoazo, thiazine, xanthene), number of sulfonic groups, basicity (element of chromophore group: S, N, O) and molecular weight of dye molecules influence their biosorption capacity. Experimental parameters such as biosorbent dose, pH, contact time, and initial dye concentration were optimized for each dye. The biosorption kinetic data were successfully described by the pseudo second-order model. The biosorption results were also analyzed by the Langmuir and Freundlich isotherms. Finally, biosorption capacities obtained using Sargassum ilicifolium were compared with the ones presented in the literature.

Density functional theory study of structural, electronic, and thermal properties of Pt, Pd, Rh, Ir, Os and PtPd X (X = Ir, Os, and Rh) alloys

NASA Astrophysics Data System (ADS)

Shabbir, Ahmed; Muhammad, Zafar; M, Shakil; M, A. Choudhary

2016-03-01

The structural, electronic, mechanical, and thermal properties of Pt, Pd, Rh, Ir, Os metals and their alloys PtPdX (X = Ir, Os and Rh) are studied systematically using ab initio density functional theory. The groundstate properties such as lattice constant and bulk modulus are calculated to find the equilibrium atomic position for stable alloys. The electronic band structure and density of states are calculated to study the electronic behavior of metals on making their alloys. The electronic properties substantiate the metallic behavior for all studied materials. The firstprinciples density functional perturbation theory as implemented in quasi-harmonic approximation is used for the calculations of thermal properties. We have calculated the thermal properties such as the Debye temperature, vibrational energy, entropy and constant-volume specific heat. The calculated properties are compared with the previously reported experimental and theoretical data for metals and are found to be in good agreement. Calculated results for alloys could not be compared because there is no data available in the literature with such alloy composition.

Habitat Complexity in Aquatic Microcosms Affects Processes Driven by Detritivores

PubMed Central

Flores, Lorea; Bailey, R. A.; Elosegi, Arturo; Larrañaga, Aitor; Reiss, Julia

2016-01-01

Habitat complexity can influence predation rates (e.g. by providing refuge) but other ecosystem processes and species interactions might also be modulated by the properties of habitat structure. Here, we focussed on how complexity of artificial habitat (plastic plants), in microcosms, influenced short-term processes driven by three aquatic detritivores. The effects of habitat complexity on leaf decomposition, production of fine organic matter and pH levels were explored by measuring complexity in three ways: 1. as the presence vs. absence of habitat structure; 2. as the amount of structure (3 or 4.5 g of plastic plants); and 3. as the spatial configuration of structures (measured as fractal dimension). The experiment also addressed potential interactions among the consumers by running all possible species combinations. In the experimental microcosms, habitat complexity influenced how species performed, especially when comparing structure present vs. structure absent. Treatments with structure showed higher fine particulate matter production and lower pH compared to treatments without structures and this was probably due to higher digestion and respiration when structures were present. When we explored the effects of the different complexity levels, we found that the amount of structure added explained more than the fractal dimension of the structures. We give a detailed overview of the experimental design, statistical models and R codes, because our statistical analysis can be applied to other study systems (and disciplines such as restoration ecology). We further make suggestions of how to optimise statistical power when artificially assembling, and analysing, ‘habitat complexity’ by not confounding complexity with the amount of structure added. In summary, this study highlights the importance of habitat complexity for energy flow and the maintenance of ecosystem processes in aquatic ecosystems. PMID:27802267

Structural studies of fungal cell-wall polysaccharides from two strains of Talaromyces flavus.

PubMed

Parra, E; Jiménez-Barbero, J; Bernabé, M; Leal, J A; Prieto, A; Gómez-Miranda, B

1994-01-03

The water-soluble cell-wall polysaccharides isolated from strains CBS 352.72 and 310.38 of Talaromyces flavus have been investigated by chemical analyses and NMR studies. Two different skeletons coexist, having the structures: [formula:see text]. The small differences between the polysaccharides isolated from both strains are probably due to slight diminution of branching in strain 352.72, as compared with strain 310.38.

Diagnosing the Quality of High School Students' and Pre-Service Chemistry Teachers' Cognitive Structures in Organic Chemistry by Using Students' Generated Systemic Synthesis Questions

ERIC Educational Resources Information Center

Hrin, Tamara; Milenkovic, Dušica; Segedinac, Mirjana

2018-01-01

The importance of well elaborated cognitive structures in a science knowledge domain has been noted in many studies. Therefore, the main aim of this particular study was to employ a new diagrammatic assessment approach, students' generated systemic synthesis questions (SSynQs), to evaluate and compare the quality of high school students' and…

Laboratory spectra of C60 and related molecular structures

NASA Technical Reports Server (NTRS)

Janca, J.; Solc, M.; Vetesnik, M.

1994-01-01

The electronic spectra of fullerene structures in high frequency discharge are studied in the plasma chemistry laboratory of the Faculty of Science of Masaryk University in Brno. The ultraviolet and visual spectra are investigated in order to be compared with the diffuse interstellar bands and interpreted within the theory of quantum mechanics. The preliminary results of the study are presented here in the form of a poster.

Discovery of riblets in a bird beak (Rynchops) for low fluid drag.

PubMed

Martin, Samuel; Bhushan, Bharat

2016-08-06

Riblet structures found on fast-swimming shark scales, such as those found on a mako shark, have been shown to reduce fluid drag. In previous experimental and modelling studies, riblets have been shown to provide drag reduction by lifting vortices formed in turbulent flow, decreasing overall shear stresses. Skimmer birds (Rynchops) are the only birds to catch fish in flight by flying just above the water surface with a submerged beak to fish for food. Because they need to quickly catch prey, reducing drag on their beak is advantageous. For the first time, riblet structures found on the beak of the skimmer bird have been studied experimentally and computationally for low fluid drag properties. In this study, skimmer replicas were studied for drag reduction through pressure drop in closed-channel, turbulent water flow. Pressure drop measurements are compared for black and yellow skimmer beaks in two configurations, and mako shark skin. In addition, two configurations of skimmer beak were modelled to compare drag properties and vortex structures. Results are discussed, and a conceptual model is presented to explain a possible drag reduction mechanism in skimmers.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

First-principles study of high-pressure structural phase transitions of magnesium

NASA Astrophysics Data System (ADS)

Liu, Qiuxiang; Fan, Changzeng; Zhang, Ruijun

2009-06-01

The structural phase transitions for the hcp, bcc, dhcp, and fcc of magnesium at hydrostatic pressures larger than about 200 GPa at zero temperature are studied by first-principles total energy calculations. The plane-wave basis pseudopotential method has been adopted, in which the generalized gradient approximation implanted in the CASTEP code is employed. By comparing the enthalpy differences of the hcp structure with other three structures under different pressures, it can be seen that when the pressure becomes higher than about 65, 130, and 190 GPa, the bcc, dhcp, and fcc structures become more stable relative to the hcp structure, respectively. Due to the lowest enthalpy value of the bcc structure above 65 GPa, it can be deduced that magnesium may transform to the bcc structure from the ground state hcp structure around 65 GPa, but no further phase transitions occur without additionally applying high temperature. In addition, the equation of state of magnesium is calculated, indicating that bcc structure is the softest phase.

Slat Noise Predictions Using Higher-Order Finite-Difference Methods on Overset Grids

NASA Technical Reports Server (NTRS)

Housman, Jeffrey A.; Kiris, Cetin

2016-01-01

Computational aeroacoustic simulations using the structured overset grid approach and higher-order finite difference methods within the Launch Ascent and Vehicle Aerodynamics (LAVA) solver framework are presented for slat noise predictions. The simulations are part of a collaborative study comparing noise generation mechanisms between a conventional slat and a Krueger leading edge flap. Simulation results are compared with experimental data acquired during an aeroacoustic test in the NASA Langley Quiet Flow Facility. Details of the structured overset grid, numerical discretization, and turbulence model are provided.

Comparative analysis of breakdown mechanism in thin SiO2 oxide films in metal-oxide-semiconductor structures under the action of heavy charged particles and a pulsed voltage

NASA Astrophysics Data System (ADS)

Zinchenko, V. F.; Lavrent'ev, K. V.; Emel'yanov, V. V.; Vatuev, A. S.

2016-02-01

Regularities in the breakdown of thin SiO2 oxide films in metal-oxide-semiconductors structures of power field-effect transistors under the action of single heavy charged particles and a pulsed voltage are studied experimentally. Using a phenomenological approach, we carry out comparative analysis of physical mechanisms and energy criteria of the SiO2 breakdown in extreme conditions of excitation of the electron subsystem in the subpicosecond time range.

Structural characterization of the Man5 glycoform of human IgG3 Fc

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, Ishan S.; Lovell, Scott; Mehzabeen, Nurjahan

Immunoglobulin G (IgG) consists of four subclasses in humans: IgG1, IgG2, IgG3 and IgG4, which are highly conserved but have unique differences that result in subclass-specific effector functions. Though IgG1 is the most extensively studied IgG subclass, study of other subclasses is important to understand overall immune function and for development of new therapeutics. When compared to IgG1, IgG3 exhibits a similar binding profile to Fcγ receptors and stronger activation of complement. All IgG subclasses are glycosylated at N297, which is required for Fcγ receptor and C1q complement binding as well as maintaining optimal Fc conformation. We have determined themore » crystal structure of homogenously glycosylated human IgG3 Fc with a GlcNAc2Man5 (Man5) high mannose glycoform at 1.8 Å resolution and compared its structural features with published structures from the other IgG subclasses. Although the overall structure of IgG3 Fc is similar to that of other subclasses, some structural perturbations based on sequence differences were revealed. For instance, the presence of R435 in IgG3 (and H435 in the other IgG subclasses) has been implicated to result in IgG3-specific properties related to binding to protein A, protein G and the neonatal Fc receptor (FcRn). The IgG3 Fc structure helps to explain some of these differences. Additionally, protein-glycan contacts observed in the crystal structure appear to correlate with IgG3 affinity for Fcγ receptors as shown by binding studies with IgG3 Fc glycoforms. Finally, this IgG3 Fc structure provides a template for further studies aimed at engineering the Fc for specific gain of function.« less

Advanced grid-stiffened composite shells for applications in heavy-lift helicopter rotor blade spars

NASA Astrophysics Data System (ADS)

Narayanan Nampy, Sreenivas

Modern rotor blades are constructed using composite materials to exploit their superior structural performance compared to metals. Helicopter rotor blade spars are conventionally designed as monocoque structures. Blades of the proposed Heavy Lift Helicopter are envisioned to be as heavy as 800 lbs when designed using the monocoque spar design. A new and innovative design is proposed to replace the conventional spar designs with light weight grid-stiffened composite shell. Composite stiffened shells have been known to provide excellent strength to weight ratio and damage tolerance with an excellent potential to reduce weight. Conventional stringer--rib stiffened construction is not suitable for rotor blade spars since they are limited in generating high torsion stiffness that is required for aeroelastic stability of the rotor. As a result, off-axis (helical) stiffeners must be provided. This is a new design space where innovative modeling techniques are needed. The structural behavior of grid-stiffened structures under axial, bending, and torsion loads, typically experienced by rotor blades need to be accurately predicted. The overall objective of the present research is to develop and integrate the necessary design analysis tools to conduct a feasibility study in employing grid-stiffened shells for heavy-lift rotor blade spars. Upon evaluating the limitations in state-of-the-art analytical models in predicting the axial, bending, and torsion stiffness coefficients of grid and grid-stiffened structures, a new analytical model was developed. The new analytical model based on the smeared stiffness approach was developed employing the stiffness matrices of the constituent members of the grid structure such as an arch, helical, or straight beam representing circumferential, helical, and longitudinal stiffeners. This analysis has the capability to model various stiffening configurations such as angle-grid, ortho-grid, and general-grid. Analyses were performed using an existing state-of-the-art and newly developed model to predict the torsion, bending, and axial stiffness of grid and grid-stiffened structures with various stiffening configurations. These predictions were compared to results generated using finite element analysis (FEA) to observe excellent correlation (within 6%) for a range of parameters for grid and grid-stiffened structures such as grid density, stiffener angle, and aspect ratio of the stiffener cross-section. Experimental results from cylindrical grid specimen testing were compared with analytical prediction using the new analysis. The new analysis predicted stiffness coefficients with nearly 7% error compared to FEA results. From the parametric studies conducted, it was observed that the previous state-of-the-art analysis on the other hand exhibited errors of the order of 39% for certain designs. Stability evaluations were also conducted by integrating the new analysis with established stability formulations. A design study was conducted to evaluate the potential weight savings of a simple grid-stiffened rotor blade spar structure compared to a baseline monocoque design. Various design constraints such as stiffness, strength, and stability were imposed. A manual search was conducted for design parameters such as stiffener density, stiffener angle, shell laminate, and stiffener aspect ratio that provide lightweight grid-stiffened designs compared to the baseline. It was found that a weight saving of 9.1% compared to the baseline is possible without violating any of the design constraints.

A Comparative Study of Airflow and Odorant Deposition in the Mammalian Nasal Cavity

NASA Astrophysics Data System (ADS)

Richter, Joseph; Rumple, Christopher; Ranslow, Allison; Quigley, Andrew; Pang, Benison; Neuberger, Thomas; Krane, Michael; van Valkenburgh, Blaire; Craven, Brent

2013-11-01

The complex structure of the mammalian nasal cavity provides a tortuous airflow path and a large surface area for respiratory air conditioning, filtering of inspired contaminants, and olfaction. Due to the small and contorted structure of the nasal turbinals, nasal anatomy and function remains poorly understood in most mammals. Here, we utilize high-resolution MRI scans to reconstruct anatomically-accurate models of the mammalian nasal cavity. These data are used to compare the form and function of the mammalian nose. High-fidelity computational fluid dynamics (CFD) simulations of nasal airflow and odorant deposition are presented and used to compare olfactory function across species (primate, rodent, canine, feline, ungulate).

The impact of domain knowledge on structured data collection and templated note design.

PubMed

Windle, T; McClay, J C; Windle, J R

2013-01-01

The objective of this case report is to evaluate the importance of specialized domain knowledge when designing and using structured templated notes in a clinical environment. To analyze the impact of specialization on structured note generation we compared notes generated for three scenarios: 1) We compared the templated history of present illness (HPI) for patients presenting with a dermatology concern to the dermatologist versus the emergency department. 2) We compared the evaluation of chest pain by ED physicians versus cardiologists. 3) Finally, we compared the data elements asked for in the evaluation of the gastrointestinal system between cardiologists and the liver transplant service (LTS). We used the SNOMED CT representation via BioPortal to evaluate specificity and grouping between data elements and specialized physician groups. We found few similarities in structured data elements designed by and for the specific physician groups. The distinctness represented both differences in granularity as well as fundamental differences in data elements requested. When compared to ED physicians, dermatologists had different and more granular elements while cardiologists requested much more granular data. Comparing cardiologists and LTS, there were differences in the data elements requested. This case study supports the importance of domain knowledge in EHR design and implementation. That different specialities should want and use different information is well supported by cognitive science literature. Despite this, it is rare for domain knowledge to be considered in EHR implementation. Physicians with correct domain knowledge should be involved in the design process of templated notes.

The Effectiveness of Dance Interventions on Physical Health Outcomes Compared to Other Forms of Physical Activity: A Systematic Review and Meta-Analysis.

PubMed

Fong Yan, Alycia; Cobley, Stephen; Chan, Cliffton; Pappas, Evangelos; Nicholson, Leslie L; Ward, Rachel E; Murdoch, Roslyn E; Gu, Yu; Trevor, Bronwyn L; Vassallo, Amy Jo; Wewege, Michael A; Hiller, Claire E

2018-04-01

Physical inactivity is one of the key global health challenges as it is associated with adverse effects related to ageing, weight control, physical function, longevity, and quality of life. Dancing is a form of physical activity associated with health benefits across the lifespan, even at amateur levels of participation. However, it is unclear whether dance interventions are equally as effective as other forms of physical activity. The aim was to systematically review the literature on the effectiveness of structured dance interventions, in comparison to structured exercise programmes, on physical health outcome measures. Seven databases were searched from earliest records to 4 August 2017. Studies investigating dance interventions lasting > 4 weeks that included physical health outcomes and had a structured exercise comparison group were included in the study. Screening and data extraction were performed by two reviewers, with all disagreements resolved by the primary author. Where appropriate, meta-analysis was performed or an effect size estimate generated. Of 11,434 studies identified, 28 (total sample size 1276 participants) met the inclusion criteria. A variety of dance genres and structured exercise interventions were compared. Meta-analyses showed dance interventions significantly improved body composition, blood biomarkers, and musculoskeletal function. The effect of either intervention on cardiovascular function and self-perceived mobility was equivalent. Undertaking structured dance of any genre is equally and occasionally more effective than other types of structured exercise for improving a range of health outcome measures. Health practitioners can recommend structured dance as a safe and effective exercise alternative.

Host and parasite life history interplay to yield divergent population genetic structures in two ectoparasites living on the same bat species.

PubMed

van Schaik, J; Dekeukeleire, D; Kerth, G

2015-05-01

Host-parasite interactions are ubiquitous in nature. However, how parasite population genetic structure is shaped by the interaction between host and parasite life history remains understudied. Studies comparing multiple parasites infecting a single host can be used to investigate how different parasite life history traits interplay with host behaviour and life history. In this study, we used 10 newly developed microsatellite loci to investigate the genetic structure of a parasitic bat fly (Basilia nana). Its host, the Bechstein's bat (Myotis bechsteinii), has a social system and roosting behaviour that restrict opportunities for parasite transmission. We compared fly genetic structure to that of the host and another parasite, the wing-mite, Spinturnix bechsteini. We found little spatial or temporal genetic structure in B. nana, suggesting a large, stable population with frequent genetic exchange between fly populations from different bat colonies. This contrasts sharply with the genetic structure of the wing-mite, which is highly substructured between the same bat colonies as well as temporally unstable. Our results suggest that although host and parasite life history interact to yield similar transmission patterns in both parasite species, the level of gene flow and eventual spatiotemporal genetic stability is differentially affected. This can be explained by the differences in generation time and winter survival between the flies and wing-mites. Our study thus exemplifies that the population genetic structure of parasites on a single host can vary strongly as a result of how their individual life history characteristics interact with host behaviour and life history traits. © 2015 John Wiley & Sons Ltd.

A proposed model for economic evaluations of major depressive disorder.

PubMed

Haji Ali Afzali, Hossein; Karnon, Jonathan; Gray, Jodi

2012-08-01

In countries like UK and Australia, the comparability of model-based analyses is an essential aspect of reimbursement decisions for new pharmaceuticals, medical services and technologies. Within disease areas, the use of models with alternative structures, type of modelling techniques and/or data sources for common parameters reduces the comparability of evaluations of alternative technologies for the same condition. The aim of this paper is to propose a decision analytic model to evaluate long-term costs and benefits of alternative management options in patients with depression. The structure of the proposed model is based on the natural history of depression and includes clinical events that are important from both clinical and economic perspectives. Considering its greater flexibility with respect to handling time, discrete event simulation (DES) is an appropriate simulation platform for modelling studies of depression. We argue that the proposed model can be used as a reference model in model-based studies of depression improving the quality and comparability of studies.

Comparative DFT study of structure, reactivity and IR spectra of phosphorus-containing dendrons with Pdbnd Nsbnd Pdbnd S linkages, vinyl and azide functional groups

NASA Astrophysics Data System (ADS)

Furer, V. L.; Vandyukov, A. E.; Majoral, J. P.; Caminade, A. M.; Gottis, S.; Laurent, R.; Kovalenko, V. I.

2015-07-01

Fourier transform IR spectra of the first generation dendrons built from thiophosphoryl core with terminal Psbnd Cl groups, vinyl (G1) and azide (G2) functional group at the level of the core have been recorded. The optimized geometries of low energy isomers of G1 and G2 have been calculated by density functional (DFT) method at the PBE/TZ2P level of theory. DFT is used for analyzing the properties of each structural part (core, branches, surface). It was found that the repeated branching units of G1 and G2 contain planar sbnd Osbnd C6H4sbnd CHdbnd Nsbnd N(CH3)sbnd Prbond2 fragments. DFT results for the structure of G1 and G2 are in good agreement with X-ray diffraction measurements. A complete vibrational assignment is proposed for different parts of G1 and G2. The global and local reactivity descriptors have been used to characterize the reactivity pattern of the core functional and terminal groups. Natural bond orbital (NBO) analysis has been applied to comparative study of charge delocalization. Our study reveals why azide group linked to phosphorus has a different reactivity when compared to organic azides.

Sexual selection and the evolution of genital shape and complexity in water striders.

PubMed

Rowe, Locke; Arnqvist, Göran

2012-01-01

Animal genitalia show two striking but incompletely understood evolutionary trends: a great evolutionary divergence in the shape of genitalic structures, and characteristic structural complexity. Both features are thought to result from sexual selection, but explicit comparative tests are hampered by the fact that it is difficult to quantify both morphological complexity and divergence in shape. We undertake a comparative study of multiple nongenitalic and male genital traits in a clade of 15 water strider species to quantify complexity and shape divergence. We show that genital structures are more complex and their shape more divergent among species than nongenital traits. Further, intromittent genital traits are more complex and have evolved more divergently than nonintromittent genital traits. More importantly, shape and complexity of nonintromittent genital traits show correlated evolution with indices of premating sexual selection and intromittent genital traits with postmating sexual selection, suggesting that the evolution of different components of genital morphology are shaped independently by distinct forms of sexual selection. Our quantitative results provide direct comparative support for the hypothesis that sexual selection is associated with morphological complexity in genitalic traits and highlight the importance of quantifying morphological shape and complexity, rather than size in studies of genital evolution. © 2011 The Author(s). Evolution © 2011 The Society for the Study of Evolution.

Exploring the Changes in Students' Understanding of the Scientific Method Using Word Associations

ERIC Educational Resources Information Center

Gulacar, Ozcan; Sinan, Olcay; Bowman, Charles R.; Yildirim, Yetkin

2015-01-01

A study is presented that explores how students' knowledge structures, as related to the scientific method, compare at different student ages. A word association test comprised of ten total stimulus words, among them "experiment," "science fair," and "hypothesis," is used to probe the students' knowledge structures.…

Shared Teaching Culture in Different Forms: A Comparison of Expert and Novice Teachers' Practices

ERIC Educational Resources Information Center

Arani, Mohammad Reza Sarkar

2017-01-01

This study aims to reveal the teaching script and structure of lesson practice of two seventh-grade Japanese mathematics teachers--a "novice" and "expert"--through comparative analysis of mathematics lessons. Specifically, it aims to clarify how the teachers' views of teaching as tacit knowledge determine lesson structure and…

Morphological Processing of Chinese Compounds from a Grammatical View

ERIC Educational Resources Information Center

Liu, Phil D.; McBride-Chang, Catherine

2010-01-01

In the present study, morphological structure processing of Chinese compounds was explored using a visual priming lexical decision task among 21 Hong Kong college students. Two compounding structures were compared. The first type was the subordinate, in which one morpheme modifies the other (e.g., [image omitted] ["laam4 kau4",…

Legislative Provisions Underlying Trade Unions' Right to Define Their Organizational Structure

ERIC Educational Resources Information Center

Korobchenko, Victoria V.; Penov, Yury V.; Safonov, Valery A.

2016-01-01

The article contains a comparative analysis of constitutional and other legislative provisions that ensure a trade union's right to define its own administrative structure in European states. The aim of the study is to reveal the management's problems of European trade unions, declarative and empirical mass-character legislative provisions, which…

The Structure of Temperament among Japanese and American Young Adults.

ERIC Educational Resources Information Center

Iwawaki, Saburo; And Others

1985-01-01

Assesses the generalizability of structure of temperament across culture. Responses of 304 Japanese college students (59.5 male) to the Dimensions of Temperament Survey (DOTS) were compared to those of the American sample studied by Lerner, Palermo, Spiro and Nesselroade (1982) through the use of confirmatory factor analytic procedures. (Author/BE)

Structuring Cooperative Learning for Motivation and Conceptual Change in the Concepts of Mixtures

ERIC Educational Resources Information Center

Belge Can, Hatice; Boz, Yezdan

2016-01-01

This study investigates the effect of structuring cooperative learning based on conceptual change approach on grade 9 students' understanding the concepts of mixtures and their motivation, compared with traditional instruction. Among six classes of a high school, two of them were randomly assigned to cooperative learning group where students were…

The Impact of Structured and Nonstructured Work Experiences on College Students' Attitudes, Values, and Academic Performance.

ERIC Educational Resources Information Center

Heller, Barbara R.; Heinemann, Harry N.

1987-01-01

A study of 353 college students compared effects of structured and nonstructured forms of work on career and school goals, attitudes toward work, and work-related values. Results indicate that working during college seems to relate to attitudes toward work, education, and student life. (CH)

Reduced Amygdalar Gray Matter Volume in Familial Pediatric Bipolar Disorder

ERIC Educational Resources Information Center

Chang, Kiki; Karchemskiy, Asya; Barnea-Goraly, Naama; Garrett, Amy; Simeonova, Diana Iorgova; Reiss, Allan

2005-01-01

Objective: Subcortical limbic structures have been proposed to be involved in the pathophysiology of adult and pediatric bipolar disorder (BD). We sought to study morphometric characteristics of these structures in pediatric subjects with familial BD compared with healthy controls. Method: Twenty children and adolescents with BD I (mean age = 14.6…

78 FR 76995 - Endangered and Threatened Wildlife and Plants; Threatened Status for Eriogonum codium (Umtanum...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-20

... bladderpod. The Bureau of Reclamation has installed a system of surface and buried drains designed to... characterize genetic diversity and compare tuplashensis and douglasii under the study design. We find the peer... irrigated private lands or manmade structures (such as buildings, pavement, or other structures) and the...

Effect of structured physical activity on prevention of serious fall injuries in adults aged 70-89: randomized clinical trial (LIFE Study)

USDA-ARS?s Scientific Manuscript database

OBJECTIVE: To test whether a long term, structured physical activity program compared with a health education program reduces the risk of serious fall injuries among sedentary older people with functional limitations. DESIGN: Multicenter, single blinded randomized trial (Lifestyle Interventions and ...

Reactance, Restoration, and Cognitive Structure: Comparative Statics

ERIC Educational Resources Information Center

Bessarabova, Elena; Fink, Edward L.; Turner, Monique

2013-01-01

This study (N = 143) examined the effects of freedom threat on cognitive structures, using recycling as its topic. The results of a 2(Freedom Threat: low vs. high) x 2(Postscript: restoration vs. filler) plus 1(Control) experiment indicated that, relative to the control condition, high freedom threat created a boomerang effect for the targeted…

Cocited Author Mapping as a Valid Representation of Intellectual Structure.

ERIC Educational Resources Information Center

McCain, Katherine W.

1986-01-01

To test validity of cocitation studies as representations of intellectual structure, five-six years of aggregate cocitation data for 41 authors in macroeconomics and 49 authors in genetics of fruit flies were compared with independent judgments of interauthor similarity collected from 14 macroeconomists and 15 geneticists via a card-sorting…

Parent Participation in School Governance: A Legal Analysis of Experiences in South Africa and Kentucky

ERIC Educational Resources Information Center

Bathon, Justin; Beckmann, Johan; Bjork, Lars G.

2011-01-01

This comparative study on the educational governance systems of South Africa and the Commonwealth of Kentucky examines legal evidence from judicial decisions and administrative law to understand similarities in how school-based governance structures have been developed. We found that although school-level governance structures may provide greater…

A Comparative Study of the Grammatical Structures of Crucian Creole and West African Languages

ERIC Educational Resources Information Center

Vergne Vargas, Aida M.

2017-01-01

This thesis examines the role of the African substrate languages in the emergence of Atlantic Creole grammatical structures. Alleyne (1980) and Faraclas (1990) have convincingly demonstrated that a survey of the grammatical features that typify the Colonial Era English-Lexifier Creoles of the Atlantic reveals remarkable similarities with those…

The Effect Structured Participation Experiences Have on Pre-Service Teachers' Preparedness to Teach Reading

ERIC Educational Resources Information Center

Brannon, Diana; Fiene, Judy

2013-01-01

Many pre-service teachers express a lack of confidence and preparedness to face the challenges of teaching reading in today's classrooms. The current study looks at whether Structured Participation Experiences (SPE) in reading increase pre-service teachers' preparedness to teach reading compared to more traditional unstructured field experiences.…

[Extraction and antioxidant activity of collagen from elephant skin, pig skin and fish scales].

PubMed

Li, Chunnan; Sun, Jiaming; Zhang, Hui

2011-08-01

To study collagen structure of the traditional Chinese medicine elephant skin and the proposed alternatives such as pig skin, fish scale, and antioxidant activity. Orthogonal experimental design method was employed to determine the optimal extraction condition of collagen from the elephant skin, and the structure and content of collagen of proposed alternatives were compared, their scavenging ability were determined by salicylic acid. Collagen extracted from elephant skin with the optimal conditions was the structural integrity and good quality first time, and collagen structure of the elephant skin was similar to the proposed alternatives. Free radical scavenging capacity of collagen, values of IC50, were 0.51 g x L(-1) of elephant skin, 0.60 g x L(-1) of pig skin and 0.42 g x L(-1) of fish scale. By comparing and identification of proteins that the collagen of elephant skin is type I collagen, with a strong antioxidant capacity, is the active ingredients of elephant skin. It provides a further study of alternatives as an important reference.

Adjustable microscopic measurement of nanogap waveguide and plasmonic structures.

PubMed

Shen, Mengqi; Learkthanakhachon, Supannee; Pechprasarn, Suejit; Zhang, Yaping; Somekh, Michael G

2018-05-01

We investigate the performance of surface plasmon and Fabry-Perot modes formed between two closely spaced layers. The motivation for this study is twofold: first, to look for modes that may be excited at lower incident angles compared to the usual Kretschmann configuration with similar or superior refractive index responsivity and, second, to develop a simple and applicable method to study these structures over a wide range of separations without recourse to the construction of ad hoc structures. Using back focal plane observation and appropriate signal processing, we show results for the Otto configuration at visible wavelengths at a range of separations not reported hitherto. Moreover, we investigate a hybrid structure we call the Kretschmann-Otto configuration that gives modes that change continuously from a hybridized surface plasmon mode to a zero-order Fabry-Perot mode. The ability to change the separation to small gap distances enables us to examine the Fabry-Perot modes where we show that it has superior refractive index responsivity, by more than an order of magnitude, compared to the Kretschmann configuration.

Investigation of advancing front method for generating unstructured grid

NASA Technical Reports Server (NTRS)

Thomas, A. M.; Tiwari, S. N.

1992-01-01

The advancing front technique is used to generate an unstructured grid about simple aerodynamic geometries. Unstructured grids are generated using VGRID2D and VGRID3D software. Specific problems considered are a NACA 0012 airfoil, a bi-plane consisting of two NACA 0012 airfoil, a four element airfoil in its landing configuration, and an ONERA M6 wing. Inviscid time dependent solutions are computed on these geometries using USM3D and the results are compared with standard test results obtained by other investigators. A grid convergence study is conducted for the NACA 0012 airfoil and compared with a structured grid. A structured grid is generated using GRIDGEN software and inviscid solutions computed using CFL3D flow solver. The results obtained by unstructured grid for NACA 0012 airfoil showed an asymmetric distribution of flow quantities, and a fine distribution of grid was required to remove this asymmetry. On the other hand, the structured grid predicted a very symmetric distribution, but when the total number of points were compared to obtain the same results it was seen that structured grid required more grid points.

Comparing HE Policies in Europe

ERIC Educational Resources Information Center

Bleiklie, Ivar; Michelsen, Svein

2013-01-01

The purpose of this paper is to develop a conceptual framework for a comparative analysis of Higher Education policies that enables us to investigate the explanatory power of structural characteristics of politico-administrative systems. The policies that are studied aim at improving the efficiency and quality of institutional performance. The…

Inmate Movements and Prison Uprisings: A Comparative Study.

ERIC Educational Resources Information Center

Pederson, William D.

1978-01-01

Fifteen "criminal" and political uprisings from inmate movements in American, Soviet, and German prisons are compared. Conditions of deprivation related to prison violence are linked with attitudinal, structural, and temporal factors. Findings are that inmate movements are a rare phenomenon in comparison with isolated prison uprisings. (KC)

A comparative study on the function and structure of medical development education office in world's top universities

PubMed Central

Ahmady, Soleiman; Yazdani, Shahram; Hosseini, Fakhrolsadat; Forouzanfar, Mohammad Mehdi; Tabibi, Ali; Ahmadinia, Fatemeh; Tehran, Hoda Ahmari; Kohan, Noushin; Mohammadi, Heidar

2018-01-01

PURPOSE: It is essential to adjust the responsibilities and function of medical education offices (MEOs) in regard to the current societal requirements. Therefore, it is a good idea to learn lessons from the experiences about the establishment and function of these offices around the world. The aim of the present study was to carry out a comparative study to investigate the function and structure of MEOs at some of the medical universities from America, Europe, and Asia. SUBJECTS AND METHODS: This is a comparative, descriptive study that was conducted in 2015. Eleven offices around the world (in America, Europe, and Asia) were selected for the study. Expert group discussion and literature review were used in order to select research sample. The data were gathered using self-constructed checklists. Content and face validity of the checklist was assessed by gathering feedback from experts. The Kappa coefficient was used to determine the inter-rater reliability. RESULTS: All the 11 offices in our study (100%) dealt with the issues of faculty development and research and scholarship activities. Only one out of the 11 offices (27%) dealt with the issues of society and patient education. Five out of the 11 offices (36%) dealt with the continuing medical education and continuing professional development. Consultation services are provided at seven of the 11 offices (64%). CONCLUSIONS: This study revealed both commonalities and differences in the function and structure of MEO among the 11 offices we examined. Based on this study, effective goals and strategies for MEO can be recommended. PMID:29922696

A comparative study on the function and structure of medical development education office in world's top universities.

PubMed

Ahmady, Soleiman; Yazdani, Shahram; Hosseini, Fakhrolsadat; Forouzanfar, Mohammad Mehdi; Tabibi, Ali; Ahmadinia, Fatemeh; Tehran, Hoda Ahmari; Kohan, Noushin; Mohammadi, Heidar

2018-01-01

It is essential to adjust the responsibilities and function of medical education offices (MEOs) in regard to the current societal requirements. Therefore, it is a good idea to learn lessons from the experiences about the establishment and function of these offices around the world. The aim of the present study was to carry out a comparative study to investigate the function and structure of MEOs at some of the medical universities from America, Europe, and Asia. This is a comparative, descriptive study that was conducted in 2015. Eleven offices around the world (in America, Europe, and Asia) were selected for the study. Expert group discussion and literature review were used in order to select research sample. The data were gathered using self-constructed checklists. Content and face validity of the checklist was assessed by gathering feedback from experts. The Kappa coefficient was used to determine the inter-rater reliability. All the 11 offices in our study (100%) dealt with the issues of faculty development and research and scholarship activities. Only one out of the 11 offices (27%) dealt with the issues of society and patient education. Five out of the 11 offices (36%) dealt with the continuing medical education and continuing professional development. Consultation services are provided at seven of the 11 offices (64%). This study revealed both commonalities and differences in the function and structure of MEO among the 11 offices we examined. Based on this study, effective goals and strategies for MEO can be recommended.

Single versus double-row repair of the rotator cuff: does double-row repair with improved anatomical and biomechanical characteristics lead to better clinical outcome?

PubMed

Pauly, Stephan; Gerhardt, Christian; Chen, Jianhai; Scheibel, Markus

2010-12-01

Several techniques for arthroscopic repair of rotator cuff defects have been introduced over the past years. Besides established techniques such as single-row repairs, new techniques such as double-row reconstructions have gained increasing interest. The present article therefore provides an overview of the currently available literature on both repair techniques with respect to several anatomical, biomechanical, clinical and structural endpoints. Systematic literature review of biomechanical, clinical and radiographic studies investigating or comparing single- and double-row techniques. These results were evaluated and compared to provide an overview on benefits and drawbacks of the respective repair type. Reconstructions of the tendon-to-bone unit for full-thickness tears in either single- or double-row technique differ with respect to several endpoints. Double-row repair techniques provide more anatomical reconstructions of the footprint and superior initial biomechanical characteristics when compared to single-row repair. With regard to clinical results, no significant differences were found while radiological data suggest a better structural tendon integrity following double-row fixation. Presently published clinical studies cannot emphasize a clearly superior technique at this time. Available biomechanical studies are in favour of double-row repair. Radiographic studies suggest a beneficial effect of double-row reconstruction on structural integrity of the reattached tendon or reduced recurrent defect rates, respectively.

Summary of Meta-Analyses Dealing with Single-Row versus Double-Row Repair Techniques for Rotator Cuff Tears

PubMed Central

Spiegl, U.J.; Euler, S.A.; Millett, P.J.; Hepp, P.

2016-01-01

Background: Several meta-analyses of randomized clinical trials have been performed to analyze whether double-row (DR) rotator cuff repair (RCR) provides superior clinical outcomes and structural healing compared to single-row (SR) repair. The purpose of this study was to sum up the results of meta-analysis comparing SR and DR repair with respect on clinical outcomes and re-tear rates. Methods: A literature search was undertaken to identify all meta-analyses dealing with randomized controlled trials comparing clinical und structural outcomes after SR versus DR RCR. Results: Eight meta-analyses met the eligibility criteria: two including Level I studies only, five including both Level I and Level II studies, and one including additional Level III studies. Four meta-analyses found no differences between SR and DR RCR for patient outcomes, whereas four favored DR RCR for tears greater than 3 cm. Two meta-analyses found no structural healing differences between SR and DR RCR, whereas six found DR repair to be superior for tears greater than 3 cm tears. Conclusion: No clinical differences are seen between single-row and double-row repair for small and medium rotator cuff tears after a short-term follow-up period with a higher re-tear rate following single-row repairs. There seems to be a trend to superior results with double-row repair in large to massive tear sizes. PMID:27708735

Comparative study on predicting Young's modulus of graphene sheets using nano-scale continuum mechanics approach

NASA Astrophysics Data System (ADS)

Rafiee, Roham; Eskandariyun, Amirali

2017-06-01

In this research, nano-scale continuum modeling is employed to predict Young's modulus of graphene sheet. The lattice nano-structure of a graphene sheet is replaced with a discrete space-frame structure simulating carbon-carbon bonds with either beam or spring elements. A comparative study is carried out to check the influence of employed elements on estimated Young's moduli of graphene sheets in both horizontal and vertical directions. A detailed analysis is also conducted to investigate the influence of graphene sheet sizes on its Young's modulus and corresponding aspect ratios that unwelcomed end effects disappear on the results are extracted. At the final stage, defected graphene sheets suffering from vacancy defects are investigated through a stochastic analysis taking into account both number of defects and their locations as random parameters. The reduction level in the Young's moduli of defected graphene sheets compared with non-defected ones is analyzed and reported.

An x-ray diffraction study of some mesoionic 2,3-diphenyltetrazoles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luboradzki, R.; Kozminski, W.; Stefaniak, L.

1993-02-01

An X-my diffraction study is reported for four molecules of mesoionic 2,3-diphenyltetrazoles. The results confirm a dipolar [open quotes]mesoionic[close quotes] structure, aromatic character of the tetrazole ring and no conjugation between the phenyl and tetrazole rings. The geometry of the exocyclic group is discussed in detail. The molecular parameters of the compounds investigated are correlated with [sup 13]C and [sup 15]N nmr data. The results obtained are compared with similar structures which have already been studied.

Factor Analysis of the Mystical Experience Questionnaire: A Study of Experiences Occasioned by the Hallucinogen Psilocybin

PubMed Central

Maclean, Katherine A.; Leoutsakos, Jeannie-Marie S.; Johnson, Matthew W.; Griffiths, Roland R.

2012-01-01

A large body of historical evidence describes the use of hallucinogenic compounds, such as psilocybin mushrooms, for religious purposes. But few scientific studies have attempted to measure or characterize hallucinogen-occasioned spiritual experiences. The present study examined the factor structure of the Mystical Experience Questionnaire (MEQ), a self-report measure that has been used to assess the effects of hallucinogens in laboratory studies. Participants (N=1602) completed the 43-item MEQ in reference to a mystical or profound experience they had had after ingesting psilocybin. Exploratory factor analysis of the MEQ retained 30 items and revealed a 4-factor structure covering the dimensions of classic mystical experience: unity, noetic quality, sacredness (F1); positive mood (F2); transcendence of time/space (F3); and ineffability (F4). MEQ factor scores showed good internal reliability and correlated with the Hood Mysticism Scale, indicating convergent validity. Participants who endorsed having had a mystical experience on psilocybin, compared to those who did not, had significantly higher factor scores, indicating construct validity. The 4-factor structure was confirmed in a second sample (N=440) and demonstrated superior fit compared to alternative models. The results provide initial evidence of the validity, reliability, and factor structure of a 30-item scale for measuring single, hallucinogen-occasioned mystical experiences, which may be a useful tool in the scientific study of mysticism. PMID:23316089

Structural models of inorganic fullerene-like structures

NASA Astrophysics Data System (ADS)

Ascencio, J. A.; Perez-Alvarez, M.; Molina, L. M.; Santiago, P.; José-Yacaman, M.

2003-03-01

In the study of fullerene-like structures, some of the more interesting systems are the inorganic cages, made of MoS 2 (usually named inorganic fullerenes), which have many important potential applications as lubricant and catalysts. In the present work, we report calculations for structural models of closed cage of inorganic fullerene-like structures for MoS 2 system. Three cage shapes were found to be the most stable: triangular pyramid, octahedron and dodecahedron. High resolution TEM images of MoS 2 cages structures were calculated to be compared with experimental data. Some examples of triangular pyramid and polyhedron in experimental MoS 2 samples are presented.

First-principles study of structural and electronic properties of Be0.25Zn0.75S mixed compound

NASA Astrophysics Data System (ADS)

Paliwal, U.; Joshi, K. B.

2018-05-01

In this work the first-principles study of structural and electronic properties of Be0.25Zn0.75S mixed compound is presented. The calculations are performed applying the QUANTUM ESPRESSO code utilizing the Perdew, Becke, Ernzerhof generalized gradient approximation in the framework of density functional theory. Adopting standard optimization strategy, the ground state equilibrium lattice constant and bulk modulus are calculated. After settling the structure the electronic band structure, bandgap and static dielectric constant are evaluated. In absence of any experimental work on this system our findings are compared with the available theoretical calculations which are found to follow well anticipated general trends.

Effects of nitrogenous substituent groups on the benzene dication

NASA Astrophysics Data System (ADS)

Forgy, C. C.; Schlimgen, A. W.; Mazziotti, D. A.

2018-05-01

The benzene dication possesses a pentagonal-pyramidal structure with a hexacoordinated carbon. In contrast, halogenated benzene dications retain a similar structure to their parent molecules. In this work, we report on theoretical studies of the structures of the dications of benzene with nitrogenous substituents. We find that the nitrobenzene dication favours a near ideal pentagonal-pyramidal structure, while the aniline dication favours a flat, hexagonal structure. Reduced-density-matrices methods give predictions in agreement with available ab initio calculations and experiment. These results are also compared with those from the Hartree-Fock method and density functional theory.

Effect of Isothermal Bainitic Quenching on Rail Steel Impact Strength and Wear Resistance

NASA Astrophysics Data System (ADS)

Çakir, Fatih Hayati; Çelik, Osman Nuri

2017-09-01

The effect of heat treatment regimes on hardness, impact strength, and wear resistance of rail steel for high-speed tracks (rail quality category R350HT) is studied. Analysis of steel properties with a different structure is compared: pearlitic, and upper and lower bainite. It is shown that the steel with bainitic structure has the best impact strength, but wear resistance is better for steel with a lower bainite structure.

CATH-Gene3D: Generation of the Resource and Its Use in Obtaining Structural and Functional Annotations for Protein Sequences.

PubMed

Dawson, Natalie L; Sillitoe, Ian; Lees, Jonathan G; Lam, Su Datt; Orengo, Christine A

2017-01-01

This chapter describes the generation of the data in the CATH-Gene3D online resource and how it can be used to study protein domains and their evolutionary relationships. Methods will be presented for: comparing protein structures, recognizing homologs, predicting domain structures within protein sequences, and subclassifying superfamilies into functionally pure families, together with a guide on using the webpages.

The evolution of structured illumination microscopy in studies of HIV.

PubMed

Marno, Kelly; Al'Zoubi, Lara; Pearson, Matthew; Posch, Markus; McKnight, Áine; Wheeler, Ann P

2015-10-15

The resolution limit of conventional light microscopy has proven to be limiting for many biological structures such as viruses including Human immunodeficiency virus (HIV). Individual HIV virions are impossible to study using confocal microscopy as they are well below the 200 nm resolution limit of conventional light microscopes. Structured illumination microscopy (SIM) allows a twofold enhancement in image resolution compared to standard widefield illumination and so provides an excellent tool for study of HIV. Viral capsids (CAs) vary between 110 and 146 nm so this study challenges the performance of SIM microscopes. SIM microscopy was first developed in 2000, commercialised in 2007 and rapidly developed. Here we present the changes in capabilities of the SIM microscopes for study of HIV localisation as the instrumentation for structured illumination microscopy has evolved over the past 8 years. Copyright © 2015. Published by Elsevier Inc.

DMS-MaPseq for genome-wide or targeted RNA structure probing in vivo.

PubMed

Zubradt, Meghan; Gupta, Paromita; Persad, Sitara; Lambowitz, Alan M; Weissman, Jonathan S; Rouskin, Silvi

2017-01-01

Coupling of structure-specific in vivo chemical modification to next-generation sequencing is transforming RNA secondary structure studies in living cells. The dominant strategy for detecting in vivo chemical modifications uses reverse transcriptase truncation products, which introduce biases and necessitate population-average assessments of RNA structure. Here we present dimethyl sulfate (DMS) mutational profiling with sequencing (DMS-MaPseq), which encodes DMS modifications as mismatches using a thermostable group II intron reverse transcriptase. DMS-MaPseq yields a high signal-to-noise ratio, can report multiple structural features per molecule, and allows both genome-wide studies and focused in vivo investigations of even low-abundance RNAs. We apply DMS-MaPseq for the first analysis of RNA structure within an animal tissue and to identify a functional structure involved in noncanonical translation initiation. Additionally, we use DMS-MaPseq to compare the in vivo structure of pre-mRNAs with their mature isoforms. These applications illustrate DMS-MaPseq's capacity to dramatically expand in vivo analysis of RNA structure.

Self-propagating high-temperature synthesis and luminescent properties of ytterbium doped rare earth (Y, Sc, Lu) oxides nanopowders

NASA Astrophysics Data System (ADS)

Permin, D. A.; Novikova, A. V.; Balabanov, S. S.; Gavrishchuk, E. M.; Kurashkin, S. V.; Savikin, A. P.

2018-04-01

This paper describes a comparative study of structural and luminescent properties of 5%Yb-doped yttrium, scandium, and lutetium oxides (Yb:RE2O3) powders and ceramics fabricated by self-propagating high-temperature synthesis. According to X-ray diffractometry and electron microscopy the chosen method ensures preparation of low-agglomerated cubic Ctype crystal structured powders at one step. No crucial differences in luminescence spectra were found the Yb:RE2O3 powders and ceramics. It was shown that the emission lifetimes of the Yb:RE2O3 powders are lowered by crystal structure defects, while its values for ceramics samples are compared to that of monocrystals and more influenced by rare earth impurities.

Effect of Si, Mg, and Mg Zn doping on structural properties of a GaN layer grown by metalorganic chemical vapor deposition

NASA Astrophysics Data System (ADS)

Cho, H. K.; Lee, J. Y.; Kim, K. S.; Yang, G. M.

2001-12-01

We have studied the structural properties of undoped, Si-doped, Mg-doped, and Mg-Zn codoped GaN using high-resolution X-ray diffraction (HRXRD) and transmission electron microscopy. When compared with undoped GaN, the dislocation density at the surface of the GaN layer decreases with Si doping and increases with Mg doping. In addition, we observed a reduction of dislocation density by codoping with Zn atoms in the Mg-doped GaN layer. The full width at half maximum of HRXRD shows that Si doping and Mg-Zn codoping improve the structural quality of the GaN layer as compared with undoped and Mg-doped GaN, respectively.

Acoustic band gaps of the woodpile sonic crystal with the simple cubic lattice

NASA Astrophysics Data System (ADS)

Wu, Liang-Yu; Chen, Lien-Wen

2011-02-01

This study theoretically and experimentally investigates the acoustic band gap of a three-dimensional woodpile sonic crystal. Such crystals are built by blocks or rods that are orthogonally stacked together. The adjacent layers are perpendicular to each other. The woodpile structure is embedded in air background. Their band structures and transmission spectra are calculated using the finite element method with a periodic boundary condition. The dependence of the band gap on the width of the stacked rods is discussed. The deaf bands in the band structure are observed by comparing with the calculated transmission spectra. The experimental transmission spectra for the Γ-X and Γ-X' directions are also presented. The calculated results are compared with the experimental results.

Comparing High-latitude Ionospheric and Thermospheric Lagrangian Coherent Structures

NASA Astrophysics Data System (ADS)

Wang, N.; Ramirez, U.; Flores, F.; Okic, D.; Datta-Barua, S.

2015-12-01

Lagrangian Coherent Structures (LCSs) are invisible boundaries in time varying flow fields that may be subject to mixing and turbulence. The LCS is defined by the local maxima of the finite time Lyapunov exponent (FTLE), a scalar field quantifying the degree of stretching of fluid elements over the flow domain. Although the thermosphere is dominated by neutral wind processes and the ionosphere is governed by plasma electrodynamics, we can compare the LCS in the two modeled flow fields to yield insight into transport and interaction processes in the high-latitude IT system. For obtaining thermospheric LCS, we use the Horizontal Wind Model 2014 (HWM14) [1] at a single altitude to generate the two-dimensional velocity field. The FTLE computation is applied to study the flow field of the neutral wind, and to visualize the forward-time Lagrangian Coherent Structures in the flow domain. The time-varying structures indicate a possible thermospheric LCS ridge in the auroral oval area. The results of a two-day run during a geomagnetically quiet period show that the structures are diurnally quasi-periodic, thus that solar radiation influences the neutral wind flow field. To find the LCS in the high-latitude ionospheric drifts, the Weimer 2001 [2] polar electric potential model and the International Geomagnetic Reference Field 11 [3] are used to compute the ExB drift flow field in ionosphere. As with the neutral winds, the Lagrangian Coherent Structures are obtained by applying the FTLE computation. The relationship between the thermospheric and ionospheric LCS is analyzed by comparing overlapping FTLE maps. Both a publicly available FTLE solver [4] and a custom-built FTLE computation are used and compared for validation [5]. Comparing the modeled IT LCSs on a quiet day with the modeled IT LCSs on a storm day indicates important factors on the structure and time evolution of the LCS.

The structural requirements of organophosphorus insecticides (OPI) for reducing chicken embryo NAD(+) content in OPI-induced teratogenesis in chickens.

PubMed

Seifert, Josef

2016-05-01

The objective of this study was to determine the structural requirements of organophosphorus insecticides (OPI) for reducing chicken embryo nicotinamide adenine dinucleotide (NAD(+)) content in OPI-induced teratogenesis and compare them with those needed for OPI inhibition of yolk sac membrane kynurenine formamidase (KFase), the proposed primary target for OPI teratogens in chicken embryos. The comparative molecular field analysis (COMFA) of three-dimensional quantitative structure-activity relationship (3D QSAR) revealed the electrostatic and steric fields as good predictors of OPI structural requirements to reduce NAD(+) content in chicken embryos. The dominant electrostatic interactions were localized at nitrogen-1, nitrogen-3, nitrogen of 2-amino substituent of the pyrimidinyl of pyrimidinyl phosphorothioates, and at the oxygen of crotonamide carbonyl in crotonamide phosphates. Bulkiness of the substituents at carbon-6 of the pyrimidinyls and/or N-substituents of crotonamides was the steric structural component that contributed to superiority of those OPI for reducing embryonic NAD(+) levels. Both electrostatic and steric requirements are similar to those defined in our previous study for OPI inhibition of chicken embryo yolk sac membrane KFase. The findings of this study provide another piece of evidence for the cause-and-effect relationship between yolk sac membrane KFase inhibition and reduced embryo NAD(+) content in NAD-associated OPI-induced teratogenesis in chickens. Copyright © 2015 Elsevier Inc. All rights reserved.

Ensemble modelling and structured decision-making to support Emergency Disease Management.

PubMed

Webb, Colleen T; Ferrari, Matthew; Lindström, Tom; Carpenter, Tim; Dürr, Salome; Garner, Graeme; Jewell, Chris; Stevenson, Mark; Ward, Michael P; Werkman, Marleen; Backer, Jantien; Tildesley, Michael

2017-03-01

Epidemiological models in animal health are commonly used as decision-support tools to understand the impact of various control actions on infection spread in susceptible populations. Different models contain different assumptions and parameterizations, and policy decisions might be improved by considering outputs from multiple models. However, a transparent decision-support framework to integrate outputs from multiple models is nascent in epidemiology. Ensemble modelling and structured decision-making integrate the outputs of multiple models, compare policy actions and support policy decision-making. We briefly review the epidemiological application of ensemble modelling and structured decision-making and illustrate the potential of these methods using foot and mouth disease (FMD) models. In case study one, we apply structured decision-making to compare five possible control actions across three FMD models and show which control actions and outbreak costs are robustly supported and which are impacted by model uncertainty. In case study two, we develop a methodology for weighting the outputs of different models and show how different weighting schemes may impact the choice of control action. Using these case studies, we broadly illustrate the potential of ensemble modelling and structured decision-making in epidemiology to provide better information for decision-making and outline necessary development of these methods for their further application. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia.

PubMed

Langen, Carolyn D; White, Tonya; Ikram, M Arfan; Vernooij, Meike W; Niessen, Wiro J

2015-01-01

Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationship between structure and function. Differences between brain lobes are visualized using "worm plots". Group differences in connections are examined with an existing visualization, the "connectogram". These visualizations were evaluated in two proof-of-concept studies: (1) middle-aged versus elderly subjects; and (2) patients with schizophrenia versus controls. Each included two measures derived from diffusion weighted images and two from functional magnetic resonance images. The structural measures were minimum cost path between two anatomical regions according to the "Statistical Analysis of Minimum cost path based Structural Connectivity" method and the average fractional anisotropy along the fiber. The functional measures were Pearson's correlation and partial correlation of mean regional time series. The relationship between structure and function was similar in both studies. Uni-modal group differences varied greatly between connectivity types. Group differences were identified in both studies globally, within brain lobes and between regions. In the aging study, minimum cost path was highly effective in identifying group differences on all levels; fractional anisotropy and mean correlation showed smaller differences on the brain lobe and regional levels. In the schizophrenia study, minimum cost path and fractional anisotropy showed differences on the global level and within brain lobes; mean correlation showed small differences on the lobe level. Only fractional anisotropy and mean correlation showed regional differences. The presented visualizations were helpful in comparing and evaluating connectivity measures on multiple levels in both studies.

The posttraumatic stress disorder project in Brazil: neuropsychological, structural and molecular neuroimaging studies in victims of urban violence.

PubMed

Bressan, Rodrigo A; Quarantini, Lucas C; Andreoli, Sérgio B; Araújo, Celia; Breen, Gerome; Guindalini, Camila; Hoexter, Marcelo; Jackowski, Andrea P; Jorge, Miguel R; Lacerda, Acioly L T; Lara, Diogo R; Malta, Stella; Moriyama, Tais S; Quintana, Maria I; Ribeiro, Wagner S; Ruiz, Juliana; Schoedl, Aline F; Shih, Ming C; Figueira, Ivan; Koenen, Karestan C; Mello, Marcelo F; Mari, Jair J

2009-06-01

Life trauma is highly prevalent in the general population and posttraumatic stress disorder is among the most prevalent psychiatric consequences of trauma exposure. Brazil has a unique environment to conduct translational research about psychological trauma and posttraumatic stress disorder, since urban violence became a Brazilian phenomenon, being particularly related to the rapid population growth of its cities. This research involves three case-control studies: a neuropsychological, a structural neuroimaging and a molecular neuroimaging study, each focusing on different objectives but providing complementary information. First, it aims to examine cognitive functioning of PTSD subjects and its relationships with symptomatology. The second objective is to evaluate neurostructural integrity of orbitofrontal cortex and hippocampus in PTSD subjects. The third aim is to evaluate if patients with PTSD have decreased dopamine transporter density in the basal ganglia as compared to resilient controls subjects. This paper shows the research rationale and design for these three case-control studies. Cases and controls will be identified through an epidemiologic survey conducted in the city of São Paulo. Subjects exposed to traumatic life experiences resulting in posttraumatic stress disorder (cases) will be compared to resilient victims of traumatic life experiences without PTSD (controls) aiming to identify biological variables that might protect or predispose to PTSD. In the neuropsychological case-control study, 100 patients with PTSD, will be compared with 100 victims of trauma without posttraumatic stress disorder, age- and sex-matched controls. Similarly, 50 cases and 50 controls will be enrolled for the structural study and 25 cases and 25 controls in the functional neuroimaging study. All individuals from the three studies will complete psychometrics and a structured clinical interview (the Structured Clinical Interview for DSM-IV and the Clinician-Administered PTSD Scale, Beck Anxiety Inventory, Beck Depression Inventory, Global Assessment of Function, The Social Adjustment Scale, Medical Outcomes Study 36-Item Short-Form Health Survey, Early Trauma Inventory, Clinical global Impressions, and Peritraumatic Dissociative Experiences Questionnaire). A broad neuropsychological battery will be administered for all participants of the neuropsychological study. Magnetic resonance scans will be performed to acquire structural neuroimaging data. Single photon emission computerized tomography with [(99m)Tc]-TRODAT-1 brain scans will be performed to evaluate dopamine transporters. This study protocol will be informative for researchers and clinicians interested in considering, designing and/or conducting translational research in the field of trauma and posttraumatic stress disorder.

Comparative structural modeling of six old yellow enzymes (OYEs) from the necrotrophic fungus Ascochyta rabiei: insight into novel OYE classes with differences in cofactor binding, organization of active site residues and stereopreferences.

PubMed

Nizam, Shadab; Gazara, Rajesh Kumar; Verma, Sandhya; Singh, Kunal; Verma, Praveen Kumar

2014-01-01

Old Yellow Enzyme (OYE1) was the first flavin-dependent enzyme identified and characterized in detail by the entire range of physical techniques. Irrespective of this scrutiny, true physiological role of the enzyme remains a mystery. In a recent study, we systematically identified OYE proteins from various fungi and classified them into three classes viz. Class I, II and III. However, there is no information about the structural organization of Class III OYEs, eukaryotic Class II OYEs and Class I OYEs of filamentous fungi. Ascochyta rabiei, a filamentous phytopathogen which causes Ascochyta blight (AB) in chickpea possesses six OYEs (ArOYE1-6) belonging to the three OYE classes. Here we carried out comparative homology modeling of six ArOYEs representing all the three classes to get an in depth idea of structural and functional aspects of fungal OYEs. The predicted 3D structures of A. rabiei OYEs were refined and evaluated using various validation tools for their structural integrity. Analysis of FMN binding environment of Class III OYE revealed novel residues involved in interaction. The ligand para-hydroxybenzaldehyde (PHB) was docked into the active site of the enzymes and interacting residues were analyzed. We observed a unique active site organization of Class III OYE in comparison to Class I and II OYEs. Subsequently, analysis of stereopreference through structural features of ArOYEs was carried out, suggesting differences in R/S selectivity of these proteins. Therefore, our comparative modeling study provides insights into the FMN binding, active site organization and stereopreference of different classes of ArOYEs and indicates towards functional differences of these enzymes. This study provides the basis for future investigations towards the biochemical and functional characterization of these enigmatic enzymes.

A novel use of 3D printing model demonstrates the effects of deteriorated trabecular bone structure on bone stiffness and strength.

PubMed

Barak, Meir Max; Black, Margaret Arielle

2018-02-01

Trabecular bone structure is crucial to normal mechanical behavior of bones. Studies have shown that osteoporosis negatively affects trabecular bone structure, mainly by reducing bone volume fraction (BV/TV) and thus increasing fracture risk. One major limitation in assessing and quantifying the effect of this structural deterioration is that no two trabecular structures are identical. Thus, when we compare a group of healthy bones against a different group of bones that experienced resorption (i.e. decreased BV/TV) we only discover an "average" mechanical effect. It is impossible to quantify the mechanical effect of individual structural deterioration for each sample, simply because we never have the same sample in both states (intact and deteriorated structure). 3D printing is a new technology that can assist in overcoming this issue. Here we report a preliminary study that compares a healthy 3D printed trabecular bone model with the same model after bone resorption was simulated. Since the deteriorated structural bone model is derived from the healthy one, it is possible to directly estimate (percentage wise) the decrease of tissue stiffness and strength as a result of bone resorption for this specific structure. Our results demonstrate that a relatively small decrease in BV/TV (about 8%) leads to a dramatic decrease in structural strength (24%) and structural stiffness (17%), (P < 0.01). Structural strength decreased from an average of 9.14 ± 2.85MPa to 6.97 ± 2.44MPa, while structural stiffness decreased from an average of 282.5 ± 63.4N/mm to 233.8 ± 51.2N/mm. This study demonstrates that 3D printing is a novel and valuable tool for quantifying the effect of structural deterioration on the mechanical properties of trabecular bone. In the future, this approach may help us attain better personal fracture risk assessments by CT scanning, 3D printing and mechanically testing individual bone replicas from patients suffering excessive bone resorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

Disruptive Effects of Colorful vs. Non-colorful Play Area on Structured Play-A Pilot Study with Preschoolers.

PubMed

Stern-Ellran, Keren; Zilcha-Mano, Sigal; Sebba, Rachel; Levit Binnun, Nava

2016-01-01

To contribute to young children's development, sensory enrichment is often provided via colorful play areas. However, little is known about the effects of colorful environments on children while they engage in age-appropriate tasks and games. Studies in adults suggest that aspects of color can distract attention and impair performance, and children are known to have less developed attentional and executive abilities than adults. Preliminary studies conducted in children aged 5-8 suggest that the colorfulness of both distal (e.g., wall decorations) and proximal (e.g., the surface of the desktop) environments can have a disruptive effect on children's performance. The present research seeks to extend the previous studies to an even younger age group and focus on proximal colorfulness. With a sample of 15 pre-schoolers (3-4 years old) we examined whether a colorful play surface compared to a non-colorful (white) play surface would affect engagement in developmentally appropriate structured play. Our pilot findings suggest that a colorful play surface interfered with preschoolers' structured play, inducing more behaviors indicating disruption in task execution compared with a non-colorful play surface. The implications of the current study for practice and further research are discussed.

Influence of sputtering power on structural and magnetic properties of as-deposited, annealed and ERTA Co2FeSi films: A comparative study

NASA Astrophysics Data System (ADS)

Saravanan, L.; Raja, M. Manivel; Prabhu, D.; Therese, H. A.

2018-02-01

We report the effect of sputtering power (200 W - 350 W) on the structural, topographical and magnetic properties of Co2FeSi (CFS) films deposited at ambient temperatures as compared to the films which were either annealed at 300 °C or were subjected to Electron beam Rapid Thermal Annealed (ERTA) treatment. The structural and morphological analyses reveal changes in their crystalline phases and particle sizes. All the as-deposited and annealed CFS films showed A2 phase crystal structure. Whereas the CFS film sputtered at 350 W followed by ERTA displayed the fully ordered L21 structure. The particles are spherical in shape and their sizes increased gradually with increase in the sputtering power of the as-deposited and annealed CFS films. However, ERTA CFS films had spherical as well as columnar (elongated) shaped grains and their grain sizes increased nonlinearly with sputtering power. M-H studies on as-deposited, annealed and ERTA CFS films show ferromagnetic responses. The comparatively stronger ferromagnetic response was observed for the ERTA samples with low saturation field which depends on the enrichment of fine crystallites in these films. This indicates that, apart from higher sputtering powers used for deposition of CFS films, ERTA process plays a significant role in the enhancement of their magnetic responses. 350 W ERTA film has the considerable saturation magnetization (∼816 emu/cc), coercivity (∼527 Oe) and a good squareness values at 100 K than at 300 K, which could originate from the spin wave excitation effect. Further, the optimized parameters to achieve a CFS film with good structural and magnetic properties are discussed from the perspective of spintronics.

Surface and electronic structure of Bi-Ca-Sr-Cu-O superconductors studied by LEED, UPS and XPS

NASA Astrophysics Data System (ADS)

Shen, Z.-X.; Lindberg, P. A. P.; Wells, B. O.; Lindau, I.; Spicer, W. E.; Mitzi, D. B.; Eom, C. B.; Kapitulnik, A.; Geballe, T. H.; Soukiassian, P.

1989-02-01

Single crystal and polycrystalline samples of Bi2CaSr2Cu2O8 have been studied by various surface sensitive techniques, including low energy electron diffraction (LEED), ultraviolet photoemission spectroscopy (UPS) and x-ray photoemission spectroscopy (XPS). The surface structure of the single crystals was characterized by LEED to be consistent with that of the bulk structure. Our data suggest that Bi2CaSr2Cu2O8 single crystals are very stable in the ultrahigh vacuu. No change of XPS spectra with temperature was observed. We have also studied the electronic structure of Bi2Sr2CuO6, which has a lower superconducting transition temperature Tc. Comparing the electronic structure of the two Bi-Ca-Sr-Cu-O superconductors, an important difference in the density of states near EF was observed which seems to be related to the difference in Tc.

Market Structure, Financial Dependence and Industrial Growth: Evidence from the Banking Industry in Emerging Asian Economies.

PubMed

Khan, Habib Hussain; Ahmad, Rubi Binit; Gee, Chan Sok

2016-01-01

In this study, we examine the role of market structure for growth in financially dependent industries from 10 emerging Asian economies over the period of 1995-2011. Our approach departs from existing studies in that we apply four alternative measures of market structure based on structural and non-structural approaches and compare their outcomes. Results indicate that higher bank concentration may slow down the growth of financially dependent industries. Bank competition on the other hand, allows financially dependent industries to grow faster. These findings are consistent across a number of sensitivity checks such as alternative measures of financial dependence, institutional factors (including property rights, quality of accounting standards and bank ownership), and endogeneity consideration. In sum, our study suggests that financially dependent industries grow more in more competitive/less concentrated banking systems. Therefore, regulatory authorities need to be careful while pursuing a consolidation policy for banking sector in emerging Asian economies.

Theoretical Study of the Structure, Stability and Oxygen Reduction Activity of Ultrathin Platinum Nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matanovic, Ivana; Kent, Paul; Garzon, Fernando

2012-10-10

We use density functional theory to study the difference in the structure, stability and catalytic reactivity between ultrathin, 0.5- 1.0 nm diameter, platinum nanotubes and nanowires. Model nanowires were formed by inserting an inner chain of platinum atoms in small diameter nanotubes. In this way more stable, nonhollow structures were formed. The difference in the electronic structure of platinum nanotubes and nanowires was examined by inspecting the density of surface states and band structure. Furthermore, reactivity towards the oxygen reduction reaction of platinum nanowires was addressed by studying the change in the chemisorption energies of oxygen and hydroxyl groups, inducedmore » by inserting the inner chain of platinum atoms into the hollow nanotubes. Both ultrathin platinum nanotubes and nanowires show distinct properties compared to bulk platinum. Nanotubes with diameters larger than 1 nm show promise for use as oxygen reduction catalysts.« less

Density Functional Study of the Structure, Stability and Oxygen Reduction Activity of Ultrathin Platinum Nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matanovic, Ivana; Kent, Paul; Garzon, Fernando

2013-03-14

We used density functional theory to study the difference in the structure, stability and catalytic reactivity between ultrathin, 0.5–1.0 nm diameter, platinum nanotubes and nanowires. Model nanowires were formed by inserting an inner chain of platinum atoms in small diameter nanotubes. In this way more stable, non-hollow structures were formed. The difference in the electronic structure of platinum nanotubes and nanowires was examined by inspecting the density of surface states and band structure. Furthermore, reactivity toward the oxygen reduction reaction of platinum nanowires was assessed by studying the change in the chemisorption energies of oxygen, hydroxyl, and hydroperoxyl groups, inducedmore » by converting the nanotube models to nanowires. Both ultrathin platinum nanotubes and nanowires show distinct properties compared to bulk platinum. Single-wall nanotubes and platinum nanowires with diameters larger than 1 nm show promise for use as oxygen reduction catalysts.« less

A study of reusable electromechanical impedance methods for structural health monitoring of civil structures

NASA Astrophysics Data System (ADS)

Tawie, R.; Na, S.; Lee, H. K.

2013-04-01

Up to date, various studies have been conducted using electro-mechanical impedance (EMI) method on concrete, including monitoring the strength development or to find damage in the structure. Since EMI method utilizes a single piezoelectric material to be used as an actuator and a sensor simultaneously, the method has major advantages compared to other non-destructive testing methods. However the method requires a piezoelectric material to be permanently attached or embedded into a structure. Thus when monitoring multiple structures, the method may become quite expensive. In this study, two re-usable EMI methods conducted by researchers Na et al and Tawie et al are overviewed. The idea of re-usable EMI method is still relatively new, resulting in the reduction of monitoring costs since the same piezoelectric material is used as many times as possible, while ensuring better repeatability and reliability in measurements.

Automatic target validation based on neuroscientific literature mining for tractography

PubMed Central

Vasques, Xavier; Richardet, Renaud; Hill, Sean L.; Slater, David; Chappelier, Jean-Cedric; Pralong, Etienne; Bloch, Jocelyne; Draganski, Bogdan; Cif, Laura

2015-01-01

Target identification for tractography studies requires solid anatomical knowledge validated by an extensive literature review across species for each seed structure to be studied. Manual literature review to identify targets for a given seed region is tedious and potentially subjective. Therefore, complementary approaches would be useful. We propose to use text-mining models to automatically suggest potential targets from the neuroscientific literature, full-text articles and abstracts, so that they can be used for anatomical connection studies and more specifically for tractography. We applied text-mining models to three structures: two well-studied structures, since validated deep brain stimulation targets, the internal globus pallidus and the subthalamic nucleus and, the nucleus accumbens, an exploratory target for treating psychiatric disorders. We performed a systematic review of the literature to document the projections of the three selected structures and compared it with the targets proposed by text-mining models, both in rat and primate (including human). We ran probabilistic tractography on the nucleus accumbens and compared the output with the results of the text-mining models and literature review. Overall, text-mining the literature could find three times as many targets as two man-weeks of curation could. The overall efficiency of the text-mining against literature review in our study was 98% recall (at 36% precision), meaning that over all the targets for the three selected seeds, only one target has been missed by text-mining. We demonstrate that connectivity for a structure of interest can be extracted from a very large amount of publications and abstracts. We believe this tool will be useful in helping the neuroscience community to facilitate connectivity studies of particular brain regions. The text mining tools used for the study are part of the HBP Neuroinformatics Platform, publicly available at http://connectivity-brainer.rhcloud.com/. PMID:26074781

Psycholinguistics: a cross-language perspective.

PubMed

Bates, E; Devescovi, A; Wulfeck, B

2001-01-01

Cross-linguistic studies are essential to the identification of universal processes in language development, language use, and language breakdown. Comparative studies in all three areas are reviewed, demonstrating powerful differences across languages in the order in which specific structures are acquired by children, the sparing and impairment of those structures in aphasic patients, and the structures that normal adults rely upon most heavily in real-time word and sentence processing. It is proposed that these differences reflect a cost-benefit trade-off among universal mechanisms for learning and processing (perception, attention, motor planning, memory) that are critical for language, but are not unique to language.

Cytological studies of lunar treated tissue cultures

NASA Technical Reports Server (NTRS)

Halliwell, R. S.

1972-01-01

An electron microscopic study was made of botanical materials, particularly pine tissues, treated with lunar materials collected by Apollo 12 quarantine mission. Results show unusual structural changes within several of the treated tissues. The bodies, as yet unidentified, resemble virus particles observed within infected plant cells. Although the size and shape of the structures are comparable to rod shaped virus particles such as Tobacco mosaic, the numerical distribution, affinity for stains, and intercellular location are different.

Effect of visual experience on structural organization of the human brain: a voxel based morphometric study using DARTEL.

PubMed

Modi, Shilpi; Bhattacharya, Manisha; Singh, Namita; Tripathi, Rajendra Prasad; Khushu, Subash

2012-10-01

To investigate structural reorganization in the brain with differential visual experience using Voxel-Based Morphometry with Diffeomorphic Anatomic Registration Through Exponentiated Lie algebra algorithm (DARTEL) approach. High resolution structural MR images were taken in fifteen normal sighted healthy controls, thirteen totally blind subjects and six partial blind subjects. The analysis was carried out using SPM8 software on MATLAB 7.6.0 platform. VBM study revealed gray matter volume atrophy in the cerebellum and left inferior parietal cortex in total blind subjects and in left inferior parietal cortex, right caudate nucleus, and left primary visual cortex in partial blind subjects as compared to controls. White matter volume loss was found in calcarine gyrus in total blind subjects and Thlamus-somatosensory region in partially blind subjects as compared to controls. Besides, an increase in Gray Matter volume was also found in left middle occipital and middle frontal gyrus and right entorhinal cortex, and an increase in White Matter volume was found in superior frontal gyrus, left middle temporal gyrus and right Heschl's gyrus in totally blind subjects as compared to controls. Comparison between total and partial blind subjects revealed a greater Gray Matter volume in left cerebellum of partial blinds and left Brodmann area 18 of total blind subjects. Results suggest that, loss of vision at an early age can induce significant structural reorganization on account of the loss of visual input. These plastic changes are different in early onset of total blindness as compared to partial blindness. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Nanocrystal grain growth and device architectures for high-efficiency CdTe ink-based photovoltaics.

PubMed

Crisp, Ryan W; Panthani, Matthew G; Rance, William L; Duenow, Joel N; Parilla, Philip A; Callahan, Rebecca; Dabney, Matthew S; Berry, Joseph J; Talapin, Dmitri V; Luther, Joseph M

2014-09-23

We study the use of cadmium telluride (CdTe) nanocrystal colloids as a solution-processable "ink" for large-grain CdTe absorber layers in solar cells. The resulting grain structure and solar cell performance depend on the initial nanocrystal size, shape, and crystal structure. We find that inks of predominantly wurtzite tetrapod-shaped nanocrystals with arms ∼5.6 nm in diameter exhibit better device performance compared to inks composed of smaller tetrapods, irregular faceted nanocrystals, or spherical zincblende nanocrystals despite the fact that the final sintered film has a zincblende crystal structure. Five different working device architectures were investigated. The indium tin oxide (ITO)/CdTe/zinc oxide structure leads to our best performing device architecture (with efficiency >11%) compared to others including two structures with a cadmium sulfide (CdS) n-type layer typically used in high efficiency sublimation-grown CdTe solar cells. Moreover, devices without CdS have improved response at short wavelengths.

Investigation on the structural effect of lignin during the hydrogenolysis process.

PubMed

Shu, Riyang; Long, Jinxing; Xu, Ying; Ma, Longlong; Zhang, Qi; Wang, Tiejun; Wang, Chenguang; Yuan, Zhengqiu; Wu, Qingyun

2016-01-01

Structure has a significant effect on the lignin degradation, so the investigation of structural effect on the lignin depolymerization is important and imperative. In this study, hydrogenolysis of three typical lignins with different structures, dealkaline lignin, sodium lignosulfonate and organosolv lignin, was intensively compared over the synergistic catalyst of CrCl3 and Pd/C. The effects of reaction temperature, time, hydrogen pressure and catalyst dosage on the catalytic performance of lignin species were investigated. The structure evolution of lignins during the hydrogenolysis process was also compared. The results showed that organosolv lignin was more sensitive for hydrogenolysis than others due to its high unsaturation degree and low molecular weight. Further analysis indicated that the hydrogenolysis, hydrodeoxygenation and repolymerization reactions took place and competed intensely. Wherein, the depolymerization products with unsaturated carbonyl groups were prone to repolymerize. And the methylation was helpful to stabilize the depolymerization products and suppress the further repolymerization. Copyright © 2015 Elsevier Ltd. All rights reserved.

Clarifying the interplate main tectonic elements of Western Anatolia, Turkey by using GNSS velocities and Bouguer gravity anomalies

NASA Astrophysics Data System (ADS)

Çırmık, Ayça; Pamukçu, Oya

2017-10-01

In this study, the GNSS and gravity data were processed and compared together for examining the continental structures of the Western Anatolia region which has very complicated tectonism. The GNSS data of three national projects were processed and GNSS velocities were found as approximately 25 mm per year towards southwest with respect to the Eurasia fixed frame. In order to investigate the interplate motions of the region, the Anatolian and Aegean block solutions were calculated and the differences in directions and amplitudes of velocities were observed particularly in the Anatolian block solution. Due to the Anatolian block solutions, the study area was grouped into three regions and compared with the tectonic structures as the first time for Western Anatolia by this study. Additionally, W-E and N-S relative GNSS solutions were obtained for observing the possible tectonic borders of the study area. Besides, 2nd order horizontal derivative and low-pass filter methods were applied to Bouguer gravity anomalies and the results of the gravity applications and the changes on crustal-mantle interface were compared with the GNSS horizontal velocities.

Lumbar muscle structure and function in chronic versus recurrent low back pain: a cross-sectional study.

PubMed

Goubert, Dorien; De Pauw, Robby; Meeus, Mira; Willems, Tine; Cagnie, Barbara; Schouppe, Stijn; Van Oosterwijck, Jessica; Dhondt, Evy; Danneels, Lieven

2017-09-01

Heterogeneity exists within the low back pain (LBP) population. Some patients recover after every pain episode, whereas others suffer daily from LBP complaints. Until now, studies rarely make a distinction between recurrent low back pain (RLBP) and chronic low back pain (CLBP), although both are characterized by a different clinical picture. Clinical experiences also indicate that heterogeneity exists within the CLBP population. Muscle degeneration, like atrophy, fat infiltration, alterations in muscle fiber type, and altered muscle activity, compromises proper biomechanics and motion of the spinal units in LBP patients. The amount of alterations in muscle structure and muscle function of the paraspinal muscles might be related to the recurrence or chronicity of LBP. The aim of this experimental study is to evaluate differences in muscle structure (cross-sectional area and lean muscle fat index) and muscle activity of the multifidus (MF) and erector spinae (ES) during trunk extension, in patients with RLBP, non-continuous CLBP, and continuous CLBP. This cross-sectional study took place in the university hospital of Ghent, Belgium. Muscle structure characteristics and muscle activity were assessed by magnetic resonance imaging (MRI). Fifty-five adults with non-specific LBP (24 RLBP in remission, 15 non-continuous CLBP, 16 continuous CLBP) participated in this study. Total cross-sectional area, muscle cross-sectional area, fat cross-sectional area, lean muscle fat index, T2-rest and T2-shift were assessed. A T1-weighted Dixon MRI scan was used to evaluate spinal muscle cross-sectional area and fat infiltration in the lumbar MF and ES. Muscle functional MRI was used to evaluate the muscle activity of the lumbar MF and ES during a lumbar extension exercise. Before and after the exercise, a pain assessment was performed. This study was supported by grants from the Special Research Fund of Ghent University (DEF12/AOP/022) without potential conflict of interest-associated biases in the text of the paper. Fat cross-sectional area and lean muscle fat index were significantly higher in MF and ES in continuous CLBP compared with non-continuous CLBP and RLBP (p<.05). No differencesbetween groups were found for total cross-sectional area and muscle cross-sectional area in MF or ES (p>.05). Also, no significant differences between groups for T2-rest were established. T2-shift, however, was significantly lower in MF and ES in RLBP compared with, respectively, non-continuous CLBP and continuous CLBP (p<.05). These results indicate a higher amount of fat infiltration in the lumbar muscles, in the absence of clear atrophy, in continuous CLBP compared with RLBP. A lower metabolic activity of the lumbar muscles was seen in RLBP replicating a relative lower intensity in contractions performed by the lumbar muscles in RLBP compared with non-continuous and continuous CLBP. In conclusion, RLBP differs from continuous CLBP for both muscle structure and muscle function, whereas non-continuous CLBP seems comparable with RLBP for lumbar muscle structure and with continuous CLBP for lumbar muscle function. These results underline the differences in muscle structure and muscle function between different LBP populations. Copyright © 2017 Elsevier Inc. All rights reserved.

Direct voxel-based comparisons between grey matter shrinkage and glucose hypometabolism in chronic alcoholism.

PubMed

Ritz, Ludivine; Segobin, Shailendra; Lannuzel, Coralie; Boudehent, Céline; Vabret, François; Eustache, Francis; Beaunieux, Hélène; Pitel, Anne L

2016-09-01

Alcoholism is associated with widespread brain structural abnormalities affecting mainly the frontocerebellar and the Papez's circuits. Brain glucose metabolism has received limited attention, and few studies used regions of interest approach and showed reduced global brain metabolism predominantly in the frontal and parietal lobes. Even though these studies have examined the relationship between grey matter shrinkage and hypometabolism, none has performed a direct voxel-by-voxel comparison between the degrees of structural and metabolic abnormalities. Seventeen alcoholic patients and 16 control subjects underwent both structural magnetic resonance imaging and (18)F-2-fluoro-deoxy-glucose-positron emission tomography examinations. Structural abnormalities and hypometabolism were examined in alcoholic patients compared with control subjects using two-sample t-tests. Then, these two patterns of brain damage were directly compared with a paired t-test. Compared to controls, alcoholic patients had grey matter shrinkage and hypometabolism in the fronto-cerebellar circuit and several nodes of Papez's circuit. The direct comparison revealed greater shrinkage than hypometabolism in the cerebellum, cingulate cortex, thalamus and hippocampus and parahippocampal gyrus. Conversely, hypometabolism was more severe than shrinkage in the dorsolateral, premotor and parietal cortices. The distinct profiles of abnormalities found within the Papez's circuit, the fronto-cerebellar circuit and the parietal gyrus in chronic alcoholism suggest the involvement of different pathological mechanisms. © The Author(s) 2015.

Direct voxel-based comparisons between grey matter shrinkage and glucose hypometabolism in chronic alcoholism

PubMed Central

Ritz, Ludivine; Segobin, Shailendra; Lannuzel, Coralie; Boudehent, Céline; Vabret, François; Eustache, Francis; Beaunieux, Hélène

2015-01-01

Alcoholism is associated with widespread brain structural abnormalities affecting mainly the frontocerebellar and the Papez’s circuits. Brain glucose metabolism has received limited attention, and few studies used regions of interest approach and showed reduced global brain metabolism predominantly in the frontal and parietal lobes. Even though these studies have examined the relationship between grey matter shrinkage and hypometabolism, none has performed a direct voxel-by-voxel comparison between the degrees of structural and metabolic abnormalities. Seventeen alcoholic patients and 16 control subjects underwent both structural magnetic resonance imaging and 18F-2-fluoro-deoxy-glucose-positron emission tomography examinations. Structural abnormalities and hypometabolism were examined in alcoholic patients compared with control subjects using two-sample t-tests. Then, these two patterns of brain damage were directly compared with a paired t-test. Compared to controls, alcoholic patients had grey matter shrinkage and hypometabolism in the fronto-cerebellar circuit and several nodes of Papez’s circuit. The direct comparison revealed greater shrinkage than hypometabolism in the cerebellum, cingulate cortex, thalamus and hippocampus and parahippocampal gyrus. Conversely, hypometabolism was more severe than shrinkage in the dorsolateral, premotor and parietal cortices. The distinct profiles of abnormalities found within the Papez’s circuit, the fronto-cerebellar circuit and the parietal gyrus in chronic alcoholism suggest the involvement of different pathological mechanisms. PMID:26661206

Structural characterization of Brachypodium genome and its syntenic relationship with rice and wheat

USDA-ARS?s Scientific Manuscript database

Brachypodium distachyon (Brachypodium) has been recently recognized as an emerging model system for both comparative and functional genomics in grass species. In this study, 55,221 repeat masked Brachypodium BAC end sequences (BES) were used for comparative analysis against the 12 rice pseudomolecul...

Amplified emission and modified spectral features in an opal hetero-structure mediated by passive defect mode localization

NASA Astrophysics Data System (ADS)

Rout, Dipak; Kumar, Govind; Vijaya, R.

2018-01-01

A photonic crystal hetero-structure consisting of a passive planar defect of SiO2 thin film sandwiched between two identical opals grown by inward growing self-assembly method using Rhodamine-B dye-doped polystyrene microspheres is studied for the characteristics of dye emission. The optical properties and the defect mode characteristics of the hetero-structure are studied from the reflection and transmission measurements. Laser-induced fluorescence from the hetero-structure showed amplified and spectrally narrowed emission compared to the photonic crystal emphasizing the role of the defect mode and distributed feedback. The enhanced emission is also complemented by the reduction in fluorescence decay time in the case of the hetero-structure in comparison to the 3D photonic crystals.

Mode structure symmetry breaking of energetic particle driven beta-induced Alfvén eigenmode

NASA Astrophysics Data System (ADS)

Lu, Z. X.; Wang, X.; Lauber, Ph.; Zonca, F.

2018-01-01

The mode structure symmetry breaking of energetic particle driven Beta-induced Alfvén Eigenmode (BAE) is studied based on global theory and simulation. The weak coupling formula gives a reasonable estimate of the local eigenvalue compared with global hybrid simulation using XHMGC. The non-perturbative effect of energetic particles on global mode structure symmetry breaking in radial and parallel (along B) directions is demonstrated. With the contribution from energetic particles, two dimensional (radial and poloidal) BAE mode structures with symmetric/asymmetric tails are produced using an analytical model. It is demonstrated that the symmetry breaking in radial and parallel directions is intimately connected. The effects of mode structure symmetry breaking on nonlinear physics, energetic particle transport, and the possible insight for experimental studies are discussed.

Oximes: Inhibitors of Human Recombinant Acetylcholinesterase. A Structure-Activity Relationship (SAR) Study

PubMed Central

Sepsova, Vendula; Karasova, Jana Zdarova; Korabecny, Jan; Dolezal, Rafael; Zemek, Filip; Bennion, Brian J.; Kuca, Kamil

2013-01-01

Acetylcholinesterase (AChE) reactivators were developed for the treatment of organophosphate intoxication. Standard care involves the use of anticonvulsants (e.g., diazepam), parasympatolytics (e.g., atropine) and oximes that restore AChE activity. However, oximes also bind to the active site of AChE, simultaneously acting as reversible inhibitors. The goal of the present study is to determine how oxime structure influences the inhibition of human recombinant AChE (hrAChE). Therefore, 24 structurally different oximes were tested and the results compared to the previous eel AChE (EeAChE) experiments. Structural factors that were tested included the number of pyridinium rings, the length and structural features of the linker, and the number and position of the oxime group on the pyridinium ring. PMID:23959117

Assessing effects of structural zeros on models of canine cancer incidence: a case study of the Swiss Canine Cancer Registry.

PubMed

Boo, Gianluca; Leyk, Stefan; Fabrikant, Sara Irina; Pospischil, Andreas; Graf, Ramona

2017-05-11

Epidemiological research of canine cancers could inform comparative studies of environmental determinants for a number of human cancers. However, such an approach is currently limited because canine cancer data sources are still few in number and often incomplete. Incompleteness is typically due to under-ascertainment of canine cancers. A main reason for this is because dog owners commonly do not seek veterinary care for this diagnosis. Deeper knowledge on under-ascertainment is critical for modelling canine cancer incidence, as an indication of zero incidence might originate from the sole absence of diagnostic examinations within a given sample unit. In the present case study, we investigated effects of such structural zeros on models of canine cancer incidence. In doing so, we contrasted two scenarios for modelling incidence data retrieved from the Swiss Canine Cancer Registry. The first scenario was based on the complete enumeration of incidence data for all Swiss municipal units. The second scenario was based on a filtered sample that systematically discarded structural zeros in those municipal units where no diagnostic examination had been performed. By means of cross-validation, we assessed and contrasted statistical performance and predictive power of the two modelling scenarios. This analytical step allowed us to demonstrate that structural zeros impact on the generalisability of the model of canine cancer incidence, thus challenging future comparative studies of canine and human cancers. The results of this case study show that increased awareness about the effects of structural zeros is critical to epidemiological research.

Characterization and evaluation of femtosecond laser-induced sub-micron periodic structures generated on titanium to improve osseointegration of implants

NASA Astrophysics Data System (ADS)

Lee, Bryan E. J.; Exir, Hourieh; Weck, Arnaud; Grandfield, Kathryn

2018-05-01

Reproducible and controllable methods of modifying titanium surfaces for dental and orthopaedic applications are of interest to prevent poor implant outcomes by improving osseointegration. This study made use of a femtosecond laser to generate laser-induced periodic surface structures with periodicities of 300, 620 and 760 nm on titanium substrates. The reproducible rippled patterns showed consistent submicron scale roughness and relatively hydrophobic surfaces as measured by atomic force microscopy and contact angle, respectively. Transmission electron microscopy and Auger electron spectroscopy identified a thicker oxide layer on ablated surfaces compared to controls. In vitro testing was conducted using osteosarcoma Saos-2 cells. Cell metabolism on the laser-ablated surfaces was comparable to controls and alkaline phosphatase activity was notably increased at late time points for the 620 and 760 nm surfaces compared to controls. Cells showed a more elongated shape on laser-ablated surfaces compared to controls and showed perpendicular alignment to the periodic structures. This work has demonstrated the feasibility of generating submicron features on an implant material with the ability to influence cell response and improve implant outcomes.

A Model Comparison for Characterizing Protein Motions from Structure

NASA Astrophysics Data System (ADS)

David, Charles; Jacobs, Donald

2011-10-01

A comparative study is made using three computational models that characterize native state dynamics starting from known protein structures taken from four distinct SCOP classifications. A geometrical simulation is performed, and the results are compared to the elastic network model and molecular dynamics. The essential dynamics is quantified by a direct analysis of a mode subspace constructed from ANM and a principal component analysis on both the FRODA and MD trajectories using root mean square inner product and principal angles. Relative subspace sizes and overlaps are visualized using the projection of displacement vectors on the model modes. Additionally, a mode subspace is constructed from PCA on an exemplar set of X-ray crystal structures in order to determine similarly with respect to the generated ensembles. Quantitative analysis reveals there is significant overlap across the three model subspaces and the model independent subspace. These results indicate that structure is the key determinant for native state dynamics.

Design, Fabrication and Test of Composite Curved Frames for Helicopter Fuselage Structure

NASA Technical Reports Server (NTRS)

Lowry, D. W.; Krebs, N. E.; Dobyns, A. L.

1984-01-01

Aspects of curved beam effects and their importance in designing composite frame structures are discussed. The curved beam effect induces radial flange loadings which in turn causes flange curling. This curling increases the axial flange stresses and induces transverse bending. These effects are more important in composite structures due to their general inability to redistribute stresses by general yielding, such as in metal structures. A detailed finite element analysis was conducted and used in the design of composite curved frame specimens. Five specimens were statically tested and compared with predicted and test strains. The curved frame effects must be accurately accounted for to avoid premature fracture; finite element methods can accurately predict most of the stresses and no elastic relief from curved beam effects occurred in the composite frames tested. Finite element studies are presented for comparative curved beam effects on composite and metal frames.

Effects of hydrogen bond on the melting point of azole explosives

NASA Astrophysics Data System (ADS)

Wang, Jian-Hua; Shen, Chen; Liu, Yu-Cun; Luo, Jin; Duan, Yingjie

2018-07-01

Melting point is an important index to determine whether an explosive can be a melt cast carrier. In this study, the relationship among the molecular structure, crystal structure, and melting point of explosives was investigated by using nitroazole compounds. Hydrogen bonds influence crystal packing modes in chemically understandable ways. Hydrogen bonds also affect the changes in entropy and enthalpy in balancing melting process. Hence, different types of hydrogen bonds in explosive crystal structures were compared when the relationship between the molecular structure and the melting point of nitroazole explosives were analyzed. The effects of methyl and amino groups on intermolecular hydrogen bonds were also compared. Results revealed that the methyl and amino groups connected on the N(1) of the heterocyclic compound can reduce the melting point of azole explosive. This finding is possible because methyl and amino groups destroy the intermolecular hydrogen bond of the heterocyclic compound.

Quantum-chemical investigation of the structures and electronic spectra of the nucleic acid bases at the coupled cluster CC2 level.

PubMed

Fleig, Timo; Knecht, Stefan; Hättig, Christof

2007-06-28

We study the ground-state structures and singlet- and triplet-excited states of the nucleic acid bases by applying the coupled cluster model CC2 in combination with a resolution-of-the-identity approximation for electron interaction integrals. Both basis set effects and the influence of dynamic electron correlation on the molecular structures are elucidated; the latter by comparing CC2 with Hartree-Fock and Møller-Plesset perturbation theory to second order. Furthermore, we investigate basis set and electron correlation effects on the vertical excitation energies and compare our highest-level results with experiment and other theoretical approaches. It is shown that small basis sets are insufficient for obtaining accurate results for excited states of these molecules and that the CC2 approach to dynamic electron correlation is a reliable and efficient tool for electronic structure calculations on medium-sized molecules.

Advancing X-ray scattering metrology using inverse genetic algorithms.

PubMed

Hannon, Adam F; Sunday, Daniel F; Windover, Donald; Kline, R Joseph

2016-01-01

We compare the speed and effectiveness of two genetic optimization algorithms to the results of statistical sampling via a Markov chain Monte Carlo algorithm to find which is the most robust method for determining real space structure in periodic gratings measured using critical dimension small angle X-ray scattering. Both a covariance matrix adaptation evolutionary strategy and differential evolution algorithm are implemented and compared using various objective functions. The algorithms and objective functions are used to minimize differences between diffraction simulations and measured diffraction data. These simulations are parameterized with an electron density model known to roughly correspond to the real space structure of our nanogratings. The study shows that for X-ray scattering data, the covariance matrix adaptation coupled with a mean-absolute error log objective function is the most efficient combination of algorithm and goodness of fit criterion for finding structures with little foreknowledge about the underlying fine scale structure features of the nanograting.

Medicinal plants used by the Tamang community in the Makawanpur district of central Nepal

PubMed Central

2014-01-01

Background We can conserve cultural heritage and gain extensive knowledge of plant species with pharmacological potential to cure simple to life-threatening diseases by studying the use of plants in indigenous communities. Therefore, it is important to conduct ethnobotanical studies in indigenous communities and to validate the reported uses of plants by comparing ethnobotanical studies with phytochemical and pharmacological studies. Materials and methods This study was conducted in a Tamang community dwelling in the Makawanpur district of central Nepal. We used semi-structured and structured questionnaires during interviews to collect information. We compared use reports with available phytochemical and pharmacological studies for validation. Results A total of 161 plant species belonging to 86 families and 144 genera to cure 89 human ailments were documented. Although 68 plant species were cited as medicinal in previous studies, 55 different uses described by the Tamang people were not found in any of the compared studies. Traditional uses for 60 plant species were consistent with pharmacological and phytochemical studies. Conclusions The Tamang people in Makawanpur are rich in ethnopharmacological understanding. The present study highlights important medicinal plant species by validating their traditional uses. Different plant species can improve local economies through proper harvesting, adequate management and development of modern techniques to maximize their use. PMID:24410808

Ferroelectric tunnel junctions with multi-quantum well structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Zhijun; Zhang, Tianjin, E-mail: zhangtj@hubu.edu.cn; Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062

Ferroelectric tunnel junctions (FTJs) with multi-quantum well structures are proposed and the tunneling electroresistance (TER) effect is investigated theoretically. Compared with conventional FTJs with monolayer ferroelectric barriers, FTJs with single-well structures provide TER ratio improvements of one order of magnitude, while FTJs with optimized multi-well structures can enhance this improvement by another order of magnitude. It is believed that the increased resonant tunneling strength combined with appropriate asymmetry in these FTJs contributes to the improvement. These studies may help to fabricate FTJs with large TER ratio experimentally and put them into practice.

Effect of UV light on different structural and transport parameters of cellophane membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benavente, J.; Vazquez, M.I.; De Abajo, J.

1996-01-01

A comparative study of UV light influence on structural and transport parameters of cellophane membranes was made. Changes in the chemical structure and electrical behavior of cellophane membranes were considered by determining the hydraulic permeability, salt diffusion coefficient, and resistance values, as well as some geometrical parameters, for an untreated membrane and two differently UV-treated cellophane membranes. Differences in the characteristic parameters for the three samples showed that radiation mainly affected the membrane structure, while only small changes in membrane electrical behavior were determined.

Knowledge-based model building of proteins: concepts and examples.

PubMed Central

Bajorath, J.; Stenkamp, R.; Aruffo, A.

1993-01-01

We describe how to build protein models from structural templates. Methods to identify structural similarities between proteins in cases of significant, moderate to low, or virtually absent sequence similarity are discussed. The detection and evaluation of structural relationships is emphasized as a central aspect of protein modeling, distinct from the more technical aspects of model building. Computational techniques to generate and complement comparative protein models are also reviewed. Two examples, P-selectin and gp39, are presented to illustrate the derivation of protein model structures and their use in experimental studies. PMID:7505680

Hemodynamic adaptation to suboptimal fetal growth in patients with single ventricle physiology.

PubMed

Alsaied, Tarek; Tseng, Stephanie; King, Eileen; Hahn, Eunice; Divanovic, Allison; Habli, Mounira; Cnota, James

2018-06-10

In fetuses with structurally normal heart and suboptimal fetal growth (SFG), umbilical artery vascular resistance increases as measured by umbilical artery pulsatility index (UA-PI). The objective of this study is to compare hemodynamic responses to SFG in fetuses with single ventricle (SV) and controls with structurally normal heart. Fetal echocardiograms around 30 weeks of gestation were reviewed. UA-PI and middle cerebral artery pulsatility index (MCA-PI) were calculated. SFG was defined as a birth weight below 25th percentile for gestational age. Studies from 92 fetuses were reviewed-SV (n = 50) and controls (n = 42). The prevalence of SFG was higher in SV compared to controls (46% vs 21%, P = .02). In patients with normal heart and SFG, UAPI was significantly higher than normal controls (P = .003) suggesting increased placental vascular resistance. In SV with SFG there was no difference in UAPI compared to SV without SFG. There was no difference in MCA-PI between the groups. The hemodynamic response to SFG in SV varies from fetuses with structurally normal heart. The mechanism of SFG and the placental pathology may be distinct in SV. © 2018 Wiley Periodicals, Inc.

Development of fire-resistant wood structural panels

NASA Technical Reports Server (NTRS)

Vaughan, T. W.; Etzold, R.

1977-01-01

Structural panels made with Xylok 210 resin as the binder had a burn-through resistance at least equal to the structural panels made with Kerimid 500. Therefore, because of its comparative ease of handling, Xylok 210 was selected as the resin binder to provide the baseline panel for the study of a means of improving the flame-spread resistance of the structural panels. The final resin-filler system consisted of Xylok 210 binder with the addition of ammonium oxalate and ammonium phosphate to the strands of the surface layers, using 24% of each salt based upon the air-dry weight of the strands. This system resulted in a panel with a flame-spread code of about 60, a Class 2 classification. A standard phenolic based structural panel had a flame-spread greater than 200 for laboratory prepared panels. The burn-through tests indicated an average burn-through time of 588 seconds for the specimens made with the final system. This compares to an average burn-through time of 287 seconds for the standard phenolic base structural specimen. One full-size panel was made with the final system.

A comparative study between experimental results and numerical predictions of multi-wall structural response to hypervelocity impact

NASA Technical Reports Server (NTRS)

Schonberg, William P.; Peck, Jeffrey A.

1992-01-01

Over the last three decades, multiwall structures have been analyzed extensively, primarily through experiment, as a means of increasing the protection afforded to spacecraft structure. However, as structural configurations become more varied, the number of tests required to characterize their response increases dramatically. As an alternative, numerical modeling of high-speed impact phenomena is often being used to predict the response of a variety of structural systems under impact loading conditions. This paper presents the results of a preliminary numerical/experimental investigation of the hypervelocity impact response of multiwall structures. The results of experimental high-speed impact tests are compared against the predictions of the HULL hydrodynamic computer code. It is shown that the hypervelocity impact response characteristics of a specific system cannot be accurately predicted from a limited number of HULL code impact simulations. However, if a wide range of impact loadings conditions are considered, then the ballistic limit curve of the system based on the entire series of numerical simulations can be used as a relatively accurate indication of actual system response.

Structured pathology reporting improves the macroscopic assessment of rectal tumour resection specimens.

PubMed

King, Simon; Dimech, Margaret; Johnstone, Susan

2016-06-01

We examined whether introduction of a structured macroscopic reporting template for rectal tumour resection specimens improved the completeness and efficiency in collecting key macroscopic data elements. Fifty free text (narrative) macroscopic reports retrieved from 2012 to 2014 were compared with 50 structured macroscopic reports from 2013 to 2015, all of which were generated at John Hunter Hospital, Newcastle, NSW. The six standard macroscopic data elements examined in this study were reported in all 50 anatomical pathology reports using a structured macroscopic reporting dictation template. Free text reports demonstrated significantly impaired data collection when recording intactness of mesorectum (p<0.001), relationship to anterior peritoneal reflection (p=0.028) and distance of tumour to the non-peritonealised circumferential margin (p<0.001). The number of words used was also significantly (p<0.001) reduced using pre-formatted structured reports compared to free text reports. The introduction of a structured reporting dictation template improves data collection and may reduce the subsequent administrative burden when macroscopically evaluating rectal resections. Copyright © 2016 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.

Fractal Loop Heat Pipe Performance Comparisons of a Soda Lime Glass and Compressed Carbon Foam Wick

NASA Technical Reports Server (NTRS)

Myre, David; Silk, Eric A.

2014-01-01

This study compares heat flux performance of a Loop Heat Pipe (LHP) wick structure fabricated from compressed carbon foam with that of a wick structure fabricated from sintered soda lime glass. Each wick was used in an LHP containing a fractal based evaporator. The Fractal Loop Heat Pipe (FLHP) was designed and manufactured by Mikros Manufacturing Inc. The compressed carbon foam wick structure was manufactured by ERG Aerospace Inc., and machined to specifications comparable to that of the initial soda lime glass wick structure. Machining of the compressed foam as well as performance testing was conducted at the United States Naval Academy. Performance testing with the sintered soda lime glass wick structures was conducted at NASA Goddard Space Flight Center. Heat input for both wick structures was supplied via cartridge heaters mounted in a copper block. The copper heater block was placed in contact with the FLHP evaporator which had a circular cross-sectional area of 0.88 cm(sup 2). Twice distilled, deionized water was used as the working fluid in both sets of experiments. Thermal performance data was obtained for three different Condenser/Subcooler temperatures under degassed conditions. Both wicks demonstrated comparable heat flux performance with a maximum of 75 W/cm observed for the soda lime glass wick and 70 W /cm(sup 2) for the compressed carbon foam wick.

Development of a rocking R/C shear wall system implementing repairable structural fuses

NASA Astrophysics Data System (ADS)

Parsafar, Saeed; Moghadam, Abdolreza S.

2017-09-01

In the last decades, the concept of earthquake resilient structural systems is becoming popular in which the rocking structure is considered as a viable option for buildings in regions of high seismicity. To this end, a novel wall-base connection based on the " repairable structure" approach is proposed and evaluated. The proposed system is made of several steel plates and high strength bolts act as a friction connection. To achieve the desired rocking motion in the proposed system, short-slotted holes are used in vertical directions for connecting the steel plates to the shear wall (SW). The experimental and numerical studies were performed using a series of displacement control quasi-static cyclic tests on a reference model and four different configurations of the proposed connection installed at the wall corners. The seismic response of the proposed system is compared to the conventional SW in terms of energy dissipation and damage accumulation. In terms of energy dissipation, the proposed system depicted better performance with 95% more energy dissipation capability compared to conventional SW. In terms of damage accumulation, the proposed SW system is nearly undamaged compared to the conventional wall system, which was severely damaged at the wall-base region. Overall, the introduced concept presents a feasible solution for R/C structures when a low-damage design is targeted, which can improve the seismic performance of the structural system significantly.

Using a structural competency framework to teach structural racism in pre-health education.

PubMed

Metzl, Jonathan M; Petty, JuLeigh; Olowojoba, Oluwatunmise V

2018-02-01

The inclusion of structural competency training in pre-health undergraduate programs may offer significant benefits to future healthcare professionals. This paper presents the results of a comparative study of an interdisciplinary pre-health curriculum based in structural competency with a traditional premedical curriculum. The authors describe the interdisciplinary pre-health curriculum, titled Medicine, Health, and Society (MHS) at Vanderbilt University. The authors then use a new survey tool, the Structural Foundations of Health Survey, to evaluate structural skills and sensibilities. The analysis compares MHS majors (n = 185) with premed science majors (n = 63) and first-semester freshmen (n = 91), with particular attention to understanding how structural factors shape health. Research was conducted from August 2015 to December 2016. Results suggest that MHS majors identified and analyzed relationships between structural factors and health outcomes at higher rates and in deeper ways than did premed science majors and freshmen, and also demonstrated higher understanding of structural and implicit racism and health disparities. The skills that MHS students exhibited represent proficiencies increasingly stressed by the MCAT, the AAMC, and other educational bodies that emphasize how contextual factors shape expressions of health and illness. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Experimental Study on Welded Headed Studs Used In Steel Plate-Concrete Composite Structures Compared with Contactless Method of Measuring Displacement

NASA Astrophysics Data System (ADS)

Kisała, Dawid; Tekieli, Marcin

2017-10-01

Steel plate-concrete composite structures are a new innovative design concept in which a thin steel plate is attached to the reinforced concrete beam by means of welded headed studs. The comparison between experimental studies and theoretical analysis of this type of structures shows that their behaviour is dependent on the load-slip relationship of the shear connectors used to ensure sufficient bond between the concrete and steel parts of the structure. The aim of this paper is to describe an experimental study on headed studs used in steel plate-concrete composite structures. Push-out tests were carried out to investigate the behaviour of shear connectors. The test specimens were prepared according to standard push-out tests, however, instead of I-beam, a steel plate 16 mm thick was used to better reflect the conditions in the real structure. The test specimens were produced in two batches using concrete with significantly different compressive strength. The experimental study was carried out on twelve specimens. Besides the traditional measurements based on LVDT sensors, optical measurements based on the digital image correlation method (DIC) and pattern tracking methods were used. DIC is a full-field contactless optical method for measuring displacements in experimental testing, based on the correlation of the digital images taken during test execution. With respect to conventional methods, optical measurements offer a wider scope of results and can give more information about the material or construction behaviour during the test. The ultimate load capacity and load-slip curves obtained from the experiments were compared with the values calculated based on Eurocodes, American and Chinese design specifications. It was observed that the use of the relationships developed for the traditional steel-concrete composite structures is justified in the case of ultimate load capacity of shear connectors in steel plate-concrete composite structures.

Adolescent depressive symptoms in India, Australia and USA: Exploratory Structural Equation Modelling of cross-national invariance and predictions by gender and age.

PubMed

Lewis, Andrew J; Rowland, Bosco; Tran, Aiden; Solomon, Renatti F; Patton, George C; Catalano, Richard F; Toumbourou, John W

2017-04-01

The present study compares depressive symptoms in adolescents from three countries: Mumbai, India; Seattle, United States; and Melbourne, Australia measured using the Short Moods and Feelings Questionnaire (SMFQ). The study cross nationally compares SMFQ depressive symptom responses by age and gender. Data from a cross-nationally matched survey were used to compare factorial and measurement characteristics from samples of students from Grade 7 and 9 in Mumbai, India (n=3268) with the equivalent cohorts in the Washington State, USA (n=1907) and Victoria, Australia (n=1900). Exploratory Structural Equation Modelling (ESEM) was used to cross-nationally examine factor structure and measurement invariance. A number of reports suggesting that SMFQ is uni-dimensional were not supported in findings from any country. A model with two factors was a better fit and suggested a first factor clustering symptoms that were affective and physiologically based symptoms and a second factor of self-critical, cognitive symptoms. The two-factor model showed convincing cross national configural invariance and acceptable measurement invariance. The present findings revealed that adolescents in Mumbai, India, reported substantially higher depressive symptoms in both factors, but particularly for the self-critical dimension, as compared to their peers in Australia and the USA and that males in Mumbai report high levels of depressive symptoms than females in Mumbai. the cross sectional study collected data for adolescents in Melbourne and Seattle in 2002 and the data for adolescents in Mumbai was obtained in 2010-2011 CONCLUSIONS: These findings suggest that previous findings in developed nations of higher depressive symptoms amongst females compared to males may have an important cultural component and cannot be generalised as a universal feature of adolescent development. Copyright © 2017 Elsevier B.V. All rights reserved.

Cognitive Style Index: Further Investigation of the Factor Structure with an American Student Sample

ERIC Educational Resources Information Center

Backhaus, Kristin; Liff, Joshua P.

2007-01-01

The present study investigates the factor structure of the Cognitive Style Index (CSI), comparing the unitary, bipolar continuum of intuition-analysis, the theory upon which the CSI is predicated, with the two-factor theory of cognitive style. We conducted both confirmatory and exploratory factor analyses on data from a sample of 222 American…

Implementing New Career Structures for Teachers: A Study of the Advanced Skills Teacher in Australia.

ERIC Educational Resources Information Center

Ingvarson, Lawrence; And Others

The absence of a professional career structure for teachers is not a new problem. In 1989, Australian unions, employers, and governments negotiated the Advanced Skills Teacher (AST) classification. Three levels of AST status involving salary increases were proposed to offer teachers a professional career path in teaching comparable in status to…

Pilot study to examine use of transverse vibration nondestructive evaluation for assessing floor systems

Treesearch

Zhiyong Cai; Robert J. Ross; Michael O. Hunt; Lawrence A. Soltis

2002-01-01

Evaluation of existing timber structures requires procedures to evaluate in situ structural members and components. This report evaluates the transverse vibration response of laboratory-built floor systems with new and salvaged joists. The objectives were to 1) compare floor system response to individual member response; 2) examine response sensitivity to location of...

Structural and functional characteristics of natural and constructed channels draining a reclaimed mountaintop removal and valley fill coal mine

EPA Science Inventory

Mountaintop removal and valley fill (MTR/VF) coal mining has altered the landscape of the Central Appalachian region in the United States. The goals of this study were to 1) compare the structure and function of natural and constructed stream channels in forested and MTR/VF catch...

Structural Studies on Intact Clostridium botulinum Neurotoxins Complexed with Inhibitors Leading to Drug Design

DTIC Science & Technology

2009-02-01

compounds via virtual screening. These compounds include small molecules – transition state analogues and benzimidazoles . Since there is a commonality in...Crystal structure of BoNT/E has been determined helping us to understand the faster action of BoNT/E compared to BoNT/A. • A subset of benzimidazole

Thematicity in Applied Linguistics Textbooks: A Comparative Study of Foreword, Introduction and Preface

ERIC Educational Resources Information Center

Jalilifar, Alireza; Montazeri, Ebtesam Abbasi

2017-01-01

While identifying the generic structure of academic introductions has been the focus of extensive research over the last few decades, investigating some, if not all, of the available linguistic resources that realize the identified generic structures seems to have been largely under-focused. In order to shed light on the way that the communicative…

Factor Structure of the Counselor Burnout Inventory in a Sample of Sexual Offender and Sexual Abuse Therapists

ERIC Educational Resources Information Center

Lee, Jayoung; Wallace, Sam; Puig, Ana; Choi, Bo Young; Nam, Suk Kyung; Lee, Sang Min

2010-01-01

This study empirically tested and compared three different models of factor structure with a sample of therapists working with sexual offenders, survivors of sexual abuse, or both. Results indicated that a modified five-factor model was the most appropriate. Practical implications for sexual offender/abuse survivor therapists are discussed.…

Practicing versus Inventing with Contrasting Cases: The Effects of Telling First on Learning and Transfer

ERIC Educational Resources Information Center

Schwartz, Daniel L.; Chase, Catherine C.; Oppezzo, Marily A.; Chin, Doris B.

2011-01-01

Being told procedures and concepts before problem solving can inadvertently undermine the learning of deep structures in physics. If students do not learn the underlying structure of physical phenomena, they will exhibit poor transfer. Two studies on teaching physics to adolescents compared the effects of "telling" students before and after…

Universal and Language-Specific Patterns in the Acquisition of Verb Argument Structures in German

ERIC Educational Resources Information Center

Leischner, Franziska N.; Weissenborn, Jürgen; Naigles, Letitia R.

2016-01-01

The study investigated the influence of universal and language-specific morpho-syntactic properties (i.e., flexible word order, case) on the acquisition of verb argument structures in German compared with English. To this end, 65 three- to nine-year-old German learning children and adults were asked to act out grammatical ("The sheep…

Two Models of Raters in a Structured Oral Examination: Does It Make a Difference?

ERIC Educational Resources Information Center

Touchie, Claire; Humphrey-Murto, Susan; Ainslie, Martha; Myers, Kathryn; Wood, Timothy J.

2010-01-01

Oral examinations have become more standardized over recent years. Traditionally a small number of raters were used for this type of examination. Past studies suggested that more raters should improve reliability. We compared the results of a multi-station structured oral examination using two different rater models, those based in a station,…

In Few Words: Linguistic Gap but Adequate Narrative Structure in Preschool Bilingual Children

ERIC Educational Resources Information Center

Bonifacci, Paola; Barbieri, Margherita; Tomassini, Marta; Roch, Maja

2018-01-01

The aim of this study was to compare linguistic and narrative skills of monolingual and bilingual preschoolers and to estimate linguistic predictors of the macro-structural level of narratives. A battery of linguistic measures in Italian was administered to sixty-four Monolinguals and sixty-four Early Bilinguals; it included Vocabulary,…

Life Satisfaction among Children in Different Family Structures: A Comparative Study of 36 Western Societies

ERIC Educational Resources Information Center

Bjarnason, Thoroddur; Bendtsen, Pernille; Arnarsson, Arsaell M.; Borup, Ina; Iannotti, Ronald J.; Lofstedt, Petra; Haapasalo, Ilona; Niclasen, Birgit

2012-01-01

This paper examines differences in life satisfaction among children in different family structures in 36 western, industrialised countries (n = 184 496). Children living with both biological parents reported higher levels of life satisfaction than children living with a single parent or parent-step-parent. Children in joint physical custody…

The Decline of Industrial Unionism in the Meatpacking Industry: Event-Structure Analyses of Labor Unrest, 1946-1987.

ERIC Educational Resources Information Center

Brueggemann, John; Brown, Cliff

2003-01-01

A study of the United Packinghouse Workers of America compared the postwar years and the Reagan era. Using event-structure analysis, the development of new corporate strategies (new technologies, production reorganization, cheap nonunion labor) fundamentally transformed the capital-labor relationship and led to the collapse of industrial unionism…

Cross-Sectional and Longitudinal Abnormalities in Brain Structure in Children with Severe Mood Dysregulation or Bipolar Disorder

ERIC Educational Resources Information Center

Adleman, Nancy E.; Fromm, Stephen J.; Razdan, Varun; Kayser, Reilly; Dickstein, Daniel P.; Brotman, Melissa A.; Pine, Daniel S.; Leibenluft, Ellen

2012-01-01

Background: There is debate as to whether chronic irritability (operationalized as severe mood dysregulation, SMD) is a developmental form of bipolar disorder (BD). Although structural brain abnormalities in BD have been demonstrated, no study compares neuroanatomy among SMD, BD, and healthy volunteers (HV) either cross-sectionally or over time.…

A two-generation analysis of pollen pool genetic structure in flowering dogwood Cornus florida (Cornaceae), in the Missouri Ozarks

Treesearch

Victoria L. Sork; Peter E. Smouse; Victoria J. Apsit; Rodney J. Dyer; Robert D. Westfall

2005-01-01

Anthropogenic landscape change can disrupt gene flow. As part of the Missouri Ozark Forest Ecosystem Project, this study examined whether silvicultural practices influence pollen-mediated gene movement in the insect-pollinated species, Cornus florida L., by comparing pollen pool structure (ΦST) among clear-cutting,...

The Effect of the Multiple-Choice Item Format on the Measurement of Knowledge of Language Structure

ERIC Educational Resources Information Center

Currie, Michael; Chiramanee, Thanyapa

2010-01-01

Noting the widespread use of multiple-choice items in tests in English language education in Thailand, this study compared their effect against that of constructed-response items. One hundred and fifty-two university undergraduates took a test of English structure first in constructed-response format, and later in three, stem-equivalent…

Constructivist-Visual Mind Map Teaching Approach and the Quality of Students' Cognitive Structures

ERIC Educational Resources Information Center

Dhindsa, Harkirat S.; Makarimi-Kasim; Anderson, O. Roger

2011-01-01

This study compared the effects of a constructivist-visual mind map teaching approach (CMA) and of a traditional teaching approach (TTA) on (a) the quality and richness of students' knowledge structures and (b) TTA and CMA students' perceptions of the extent that a constructivist learning environment (CLE) was created in their classes. The sample…

NASTRAN Analysis Comparison to Shock Tube Tests Used to Simulate Nuclear Overpressures

NASA Technical Reports Server (NTRS)

Wheless, T. K.

1985-01-01

This report presents a study of the effectiveness of the NASTRAN computer code for predicting structural response to nuclear blast overpressures. NASTRAN's effectiveness is determined by comparing results against shock tube tests used to simulate nuclear overpressures. Seven panels of various configurations are compared in this study. Panel deflections are the criteria used to measure NASTRAN's effectiveness. This study is a result of needed improvements in the survivability/vulnerability analyses subjected to nuclear blast.

[Molecular genetic study of the beluga (Delphinapterus leucas: Cetacea, Monodontidae) summering in the southern Sea of Okhotsk as compared to North American populations].

PubMed

Meshcherskiĭ, I G; Kholodova, M V; Zvychaĭnaia, E Iu

2008-09-01

The structure of the left part of the mtDNA control region has been studied in Delphinapterus leucas captured in summer in the southern Sea of Okhotsk. The data have been compared with published results of similar studies on D. leucas at different sites along the American coast. A high specificity of maternal lineages of D. leucas from the southern Sea of Ok.

Structured-light 3D scanner in use to assess the human body posture in physical therapy - a pilot study.

PubMed

Kurzydło, Wojciech; Stach, Beata; Bober, Aleksandra; Wodzińska, Mariola; Długosz, Mirosława M

2014-01-01

The main goal of this study was to asses the possibility of using mass production structured-light 3d scanner to asses human body posture. The study was conducted on a healthy 23 year old volunteer and a lay-figure. The experiment consisted of 28 3D scans, divided into three separate tests. The largest deviation observed in the first two trials was 24.42 mm. While the largest deviation observed in the third trial was 49.91 mm. Data obtained with the mass production structured-light 3d scanner may have comparable or better performance than commercially available systems for the assessment of BP.

Theoretical studies of Pt-Ti nanoparticles for potential use as PEMFC electrocatalysts.

PubMed

Jennings, Paul C; Pollet, Bruno G; Johnston, Roy L

2012-03-07

A theoretical investigation is presented of alloying platinum with titanium to form binary Pt-Ti nanoalloys as an alternative to the expensive pure platinum catalysts commonly used for Proton Exchange Membrane Fuel Cell cathode electrocatalysts. Density Functional Theory calculations are performed to investigate compositional effects on structural properties as well as Oxygen Reduction Reaction kinetics and poisoning effects. High symmetry A(32)-B(6) clusters are studied to investigate structural properties. From these structures binding energies of hydroxyl and carbon monoxide are studied on a range of sites on the surface of the clusters. Promising results are obtained suggesting that the bimetallic Pt-Ti nanoalloys may exhibit enhanced properties compared to pure platinum catalysts.

Conceptual Design Study on Bolts for Self-Loosing Preventable Threaded Fasteners

NASA Astrophysics Data System (ADS)

Noma, Atsushi; He, Jianmei

2017-11-01

Threaded fasteners using bolts is widely applied in industrial field as well as various fields. However, threaded fasteners using bolts have loosing problems and cause many accidents. In this study, the purpose is to obtain self-loosing preventable threaded fasteners by applying spring characteristic effects on bolt structures. Helical-cutting applied bolt structures is introduced through three dimensional (3D) CAD modeling tools. Analytical approaches for evaluations on the spring characteristic effects helical-cutting applied bolt structures and self-loosing preventable performance of threaded fasteners were performed using finite element method and results are reported. Comparing slackness test results with analytical results and more details on evaluating mechanical properties will be executed in future study.

Image quality of mixed convolution kernel in thoracic computed tomography.

PubMed

Neubauer, Jakob; Spira, Eva Maria; Strube, Juliane; Langer, Mathias; Voss, Christian; Kotter, Elmar

2016-11-01

The mixed convolution kernel alters his properties geographically according to the depicted organ structure, especially for the lung. Therefore, we compared the image quality of the mixed convolution kernel to standard soft and hard kernel reconstructions for different organ structures in thoracic computed tomography (CT) images.Our Ethics Committee approved this prospective study. In total, 31 patients who underwent contrast-enhanced thoracic CT studies were included after informed consent. Axial reconstructions were performed with hard, soft, and mixed convolution kernel. Three independent and blinded observers rated the image quality according to the European Guidelines for Quality Criteria of Thoracic CT for 13 organ structures. The observers rated the depiction of the structures in all reconstructions on a 5-point Likert scale. Statistical analysis was performed with the Friedman Test and post hoc analysis with the Wilcoxon rank-sum test.Compared to the soft convolution kernel, the mixed convolution kernel was rated with a higher image quality for lung parenchyma, segmental bronchi, and the border between the pleura and the thoracic wall (P < 0.03). Compared to the hard convolution kernel, the mixed convolution kernel was rated with a higher image quality for aorta, anterior mediastinal structures, paratracheal soft tissue, hilar lymph nodes, esophagus, pleuromediastinal border, large and medium sized pulmonary vessels and abdomen (P < 0.004) but a lower image quality for trachea, segmental bronchi, lung parenchyma, and skeleton (P < 0.001).The mixed convolution kernel cannot fully substitute the standard CT reconstructions. Hard and soft convolution kernel reconstructions still seem to be mandatory for thoracic CT.

Structure formation of 5083 alloy during friction stir welding

NASA Astrophysics Data System (ADS)

Zaikina, A. A.; Kolubaev, A. V.; Sizova, O. V.; Ivanov, K. V.; Filippov, A. V.; Kolubaev, E. A.

2017-12-01

This paper provides a comparative study of structures obtained by friction stir welding and sliding friction of 5083 Al alloy. Optical and electron microscopy reveals identical fine-grained structures with a grain size of ˜5 µm both in the weld nugget zone and subsurface layer in friction independently of the initial grain size of the alloy. It has been suggested that the grain boundary sliding is responsible for the specific material flow pattern in both techniques considered.

Comparison and Analysis of Steel Frame Based on High Strength Column and Normal Strength Column

NASA Astrophysics Data System (ADS)

Liu, Taiyu; An, Yuwei

2018-01-01

The anti-seismic performance of high strength steel has restricted its industrialization in civil buildings. In order to study the influence of high strength steel column on frame structure, three models are designed through MIDAS/GEN finite element software. By comparing the seismic performance and economic performance of the three models, the three different structures are comprehensively evaluated to provide some references for the development of high strength steel in steel structure.

The 2.1Å Crystal Structure of an Acyl-CoA Synthetase from Methanosarcina acetivorans reveals an alternate acyl binding pocket for small branched acyl substrates†,‡

PubMed Central

Shah, Manish B.; Ingram-Smith, Cheryl; Cooper, Leroy L.; Qu, Jun; Meng, Yu; Smith, Kerry S.; Gulick, Andrew M.

2009-01-01

The acyl-AMP forming family of adenylating enzymes catalyze two-step reactions to activate a carboxylate with the chemical energy derived from ATP hydrolysis. X-ray crystal structures have been determined for multiple members of this family and, together with biochemical studies, provide insights into the active site and catalytic mechanisms used by these enzymes. These studies have shown that the enzymes use a domain rotation of 140° to reconfigure a single active site to catalyze the two partial reactions. We present here the crystal structure of a new medium chain acyl-CoA synthetase from Methanosarcina acetivorans. The binding pocket for the three substrates is analyzed, with many conserved residues present in the AMP binding pocket. The CoA binding pocket is compared to the pockets of both acetyl-CoA synthetase and 4-chlorobenzoate:CoA ligase. Most interestingly, the acyl binding pocket of the new structure is compared with other acyl- and aryl-CoA synthetases. A comparison of the acyl-binding pocket of the acyl-CoA synthetase from M. acetivorans with other structures identifies a shallow pocket that is used to bind the medium chain carboxylates. These insights emphasize the high sequence and structural diversity among this family in the area of the acyl binding pocket. PMID:19544569

Composite Structure Modeling and Analysis of Advanced Aircraft Fuselage Concepts

NASA Technical Reports Server (NTRS)

Mukhopadhyay, Vivek; Sorokach, Michael R.

2015-01-01

NASA Environmentally Responsible Aviation (ERA) project and the Boeing Company are collabrating to advance the unitized damage arresting composite airframe technology with application to the Hybrid-Wing-Body (HWB) aircraft. The testing of a HWB fuselage section with Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) construction is presently being conducted at NASA Langley. Based on lessons learned from previous HWB structural design studies, improved finite-element models (FEM) of the HWB multi-bay and bulkhead assembly are developed to evaluate the performance of the PRSEUS construction. In order to assess the comparative weight reduction benefits of the PRSEUS technology, conventional cylindrical skin-stringer-frame models of a cylindrical and a double-bubble section fuselage concepts are developed. Stress analysis with design cabin-pressure load and scenario based case studies are conducted for design improvement in each case. Alternate analysis with stitched composite hat-stringers and C-frames are also presented, in addition to the foam-core sandwich frame and pultruded rod-stringer construction. The FEM structural stress, strain and weights are computed and compared for relative weight/strength benefit assessment. The structural analysis and specific weight comparison of these stitched composite advanced aircraft fuselage concepts demonstrated that the pressurized HWB fuselage section assembly can be structurally as efficient as the conventional cylindrical fuselage section with composite stringer-frame and PRSEUS construction, and significantly better than the conventional aluminum construction and the double-bubble section concept.

Ab Initio -Based Bond Order Potential to Investigate Low Thermal Conductivity of Stanene Nanostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cherukara, Mathew J.; Narayanan, Badri; Kinaci, Alper

2016-08-28

We introduce a bond order potential (BOP) for stanene based on an ab initio derived training data set. The potential is optimized to accurately describe the energetics, as well as thermal and mechanical properties of a free-standing sheet, and used to study diverse nanostructures of stanene, including tubes and ribbons. As a representative case study, using the potential, we perform molecular dynamics simulations to study stanene’s structure and temperature-dependent thermal conductivity. We find that the structure of stanene is highly rippled, far in excess of other 2-D materials (e.g., graphene), owing to its low in-plane stiffness (stanene: ~ 25 N/m;more » graphene: ~ 480 N/ m). The extent of stanene’s rippling also shows stronger temperature dependence compared to that in graphene. Furthermore, we find that stanene based nanostructures have significantly lower thermal conductivity compared to graphene based structures owing to their softness (i.e., low phonon group velocities) and high anharmonic response. Our newly developed BOP will facilitate the exploration of stanene based low dimensional heterostructures for thermoelectric and thermal management applications.« less

In vivo imaging of human burn injuries with polarization-sensitive optical coherence tomography

NASA Astrophysics Data System (ADS)

Kim, Ki Hean; Pierce, Mark C.; Maguluri, Gopi; Park, B. Hyle; Yoon, Sang June; Lydon, Martha; Sheridan, Robert; de Boer, Johannes F.

2012-06-01

The accurate determination of burn depth is critical in the clinical management of burn wounds. Polarization-sensitive optical coherence tomography (PS-OCT) has been proposed as a potentially non-invasive method for determining burn depth by measuring thermally induced changes in the structure and birefringence of skin, and has been investigated in pre-clinical burn studies with animal models and ex vivo human skin. In this study, we applied PS-OCT to the in-vivo imaging of two pediatric burn patients. Deep and superficial burned skins along with contralateral controls were imaged in 3D. The imaging size was 8 mm×6 mm×2 mm in width, length, and depth in the air respectively, and the imaging time was approximately 6 s per volume. Superficially burned skins exhibited the same layered structure as the contralateral controls, but more visible vasculature and reduced birefringence compared to the contralateral controls. In contrast, a deeply burned skin showed loss of the layered structure, almost absent vasculature, and smaller birefringence compared to superficial burns. This study suggested the vasculature and birefringence as parameters for characterizing burn wounds.

Comparative genetic structure between Sedum ussuriense and S. kamtschaticum (Crassulaceae), two stonecrops co-occurring on rocky cliffs.

PubMed

Chung, Mi Yoon; López-Pujol, Jordi; Chung, Myong Gi

2014-06-01

• Premise of the study: Geographic isolation due to discontinuities of suitable habitat may have significant effects on the genetic structure of plant populations. Even within a few kilometers, physical barriers to gene flow may lead to considerable genetic differentiation among populations.• Methods: Sedum ussuriense is a boreal species that in Korea occurs only in four valleys separated by mountain ranges in Juwangsan National Park and its vicinity (a range of ∼15 km). Its congener S. kamtschaticum, by contrast, co-occurs in the four valleys but also on the intervening mountains. Using 12 allozyme loci, we comparatively assessed genetic variability and structure in 12 population pairs of the two stonecrops.• Key results: While we found high and comparable levels of within-population genetic variation for the two species, among-population divergence was significantly higher in S. ussuriense (F ST = 0.261 vs. F ST = 0.165). Sedum ussuriense also showed a much higher percentage of among-valley variation (19%) than S. kamtschaticum (4%).• Conclusions: High levels of genetic diversity in the two Sedum species are consistent with the previous hypothesis that mountains of the Korean Peninsula served as glacial refugia for many boreal species. Given that the two congeners have similar life-history traits, the lower among-population differentiation in S. kamtschaticum is attributable to its higher abundance and more continuous distribution in the study area. This study confirms the central role of geographic isolation in the genetic structure of plant species even at very small scales. © 2014 Botanical Society of America, Inc.

With medium-chain triglycerides, higher and faster oxygen radical production by stimulated polymorphonuclear leukocytes occurs.

PubMed

Kruimel, J W; Naber, A H; Curfs, J H; Wenker, M A; Jansen, J B

2000-01-01

Parenteral lipid emulsions are suspected of suppressing the immune function. However, study results are contradictory and mainly concern the conventional long-chain triglyceride emulsions. Polymorphonuclear leukocytes were preincubated with parenteral lipid emulsions. The influence of the lipid emulsions on the production of oxygen radicals by these stimulated leukocytes was studied by measuring chemiluminescence. Three different parenteral lipid emulsions were tested: long-chain triglycerides, a physical mixture of medium- and long-chain triglycerides, and structured triglycerides. Structured triglycerides consist of triglycerides where the medium- and long-chain fatty acids are attached to the same glycerol molecule. Stimulated polymorphonuclear leukocytes preincubated with the physical mixture of medium- and long-chain triglycerides showed higher levels of oxygen radicals (p < .005) and faster production of oxygen radicals (p < .005) compared with polymorphonuclear leukocytes preincubated with long-chain triglycerides or structured triglycerides. Additional studies indicated that differences in results of various lipid emulsions were not caused by differences in emulsifier. The overall production of oxygen radicals was significantly lower after preincubation with the three lipid emulsions compared with controls without lipid emulsion. A physical mixture of medium- and long-chain triglycerides induced faster production of oxygen radicals, resulting in higher levels of oxygen radicals, compared with long-chain triglycerides or structured triglycerides. This can be detrimental in cases where oxygen radicals play either a pathogenic role or a beneficial one, such as when rapid phagocytosis and killing of bacteria is needed. The observed lower production of oxygen radicals by polymorphonuclear leukocytes in the presence of parenteral lipid emulsions may result in immunosuppression by these lipids.

Detection of lobular structures in normal breast tissue.

PubMed

Apou, Grégory; Schaadt, Nadine S; Naegel, Benoît; Forestier, Germain; Schönmeyer, Ralf; Feuerhake, Friedrich; Wemmert, Cédric; Grote, Anne

2016-07-01

Ongoing research into inflammatory conditions raises an increasing need to evaluate immune cells in histological sections in biologically relevant regions of interest (ROIs). Herein, we compare different approaches to automatically detect lobular structures in human normal breast tissue in digitized whole slide images (WSIs). This automation is required to perform objective and consistent quantitative studies on large data sets. In normal breast tissue from nine healthy patients immunohistochemically stained for different markers, we evaluated and compared three different image analysis methods to automatically detect lobular structures in WSIs: (1) a bottom-up approach using the cell-based data for subsequent tissue level classification, (2) a top-down method starting with texture classification at tissue level analysis of cell densities in specific ROIs, and (3) a direct texture classification using deep learning technology. All three methods result in comparable overall quality allowing automated detection of lobular structures with minor advantage in sensitivity (approach 3), specificity (approach 2), or processing time (approach 1). Combining the outputs of the approaches further improved the precision. Different approaches of automated ROI detection are feasible and should be selected according to the individual needs of biomarker research. Additionally, detected ROIs could be used as a basis for quantification of immune infiltration in lobular structures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative Logic Modeling for Policy Analysis: The Case of HIV Testing Policy Change at the Department of Veterans Affairs

PubMed Central

Langer, Erika M; Gifford, Allen L; Chan, Kee

2011-01-01

Objective Logic models have been used to evaluate policy programs, plan projects, and allocate resources. Logic Modeling for policy analysis has been used rarely in health services research but can be helpful in evaluating the content and rationale of health policies. Comparative Logic Modeling is used here on human immunodeficiency virus (HIV) policy statements from the Department of Veterans Affairs (VA) and Centers for Disease Control and Prevention (CDC). We created visual representations of proposed HIV screening policy components in order to evaluate their structural logic and research-based justifications. Data Sources and Study Design We performed content analysis of VA and CDC HIV testing policy documents in a retrospective case study. Data Collection Using comparative Logic Modeling, we examined the content and primary sources of policy statements by the VA and CDC. We then quantified evidence-based causal inferences within each statement. Principal Findings VA HIV testing policy structure largely replicated that of the CDC guidelines. Despite similar design choices, chosen research citations did not overlap. The agencies used evidence to emphasize different components of the policies. Conclusion Comparative Logic Modeling can be used by health services researchers and policy analysts more generally to evaluate structural differences in health policies and to analyze research-based rationales used by policy makers. PMID:21689094

Antireflection effect of femtosecond laser-induced periodic surface structures on silicon.

PubMed

Vorobyev, A Y; Guo, Chunlei

2011-09-12

Following direct femtosecond laser pulse irradiation, we produce a unique grating structure over a large area superimposed by finer nanostructures on a silicon wafer. We study, for the first time, the antireflection effect of this femtosecond laser-induced periodic surface structures (FLIPSSs) in the wavelength range of 250 - 2500 nm. Our study shows that the FLIPSSs suppress both the total hemispherical and specular polarized reflectance of silicon surface significantly over the entire studied wavelength range. The total polarized reflectance of the processed surface is reduced by a factor of about 3.5 in the visible and 7 in the UV compared to an untreated sample. The antireflection effect of the FLIPSS surface is broadband and the suppression stays to the longest wavelength (2500 nm) studied here although the antireflection effect in the infrared is weaker than in the visible. Our FLIPSS structures are free of chemical contamination, highly durable, and easily controllable in size.

Estimates of production and structure of nuclei with Z = 119

NASA Astrophysics Data System (ADS)

Adamian, G. G.; Antonenko, N. V.; Lenske, H.

2018-02-01

The comparative analysis of the hot fusion reactions 50Ti +247-249Bk and 51V +246-248Cm for synthesis of element 119 is made with the dinuclear system model and the prediction of nuclear properties of the microscopic-macroscopic approach, where the closed proton shell at Z ≥ 120 is expected. The quasiparticle structures of nuclei in the α-decay chain of 295119 and a possible spread of alpha energies are studied. The calculated values of Qα are compared with available experimental data. The termination of the α-decay chain of 295119 is revealed.

Quantitative magneto-optical investigation of superconductor/ferromagnet hybrid structures

NASA Astrophysics Data System (ADS)

Shaw, G.; Brisbois, J.; Pinheiro, L. B. G. L.; Müller, J.; Blanco Alvarez, S.; Devillers, T.; Dempsey, N. M.; Scheerder, J. E.; Van de Vondel, J.; Melinte, S.; Vanderbemden, P.; Motta, M.; Ortiz, W. A.; Hasselbach, K.; Kramer, R. B. G.; Silhanek, A. V.

2018-02-01

We present a detailed quantitative magneto-optical imaging study of several superconductor/ferromagnet hybrid structures, including Nb deposited on top of thermomagnetically patterned NdFeB and permalloy/niobium with erasable and tailored magnetic landscapes imprinted in the permalloy layer. The magneto-optical imaging data are complemented with and compared to scanning Hall probe microscopy measurements. Comprehensive protocols have been developed for calibrating, testing, and converting Faraday rotation data to magnetic field maps. Applied to the acquired data, they reveal the comparatively weaker magnetic response of the superconductor from the background of larger fields and field gradients generated by the magnetic layer.

Comparing photonic band structure calculation methods for diamond and pyrochlore crystals.

PubMed

Vermolen, E C M; Thijssen, J H J; Moroz, A; Megens, M; van Blaaderen, A

2009-04-27

The photonic band diagrams of close-packed colloidal diamond and pyrochlore structures, have been studied using Korringa-Kohn-Rostoker (KKR) and plane-wave calculations. In addition, the occurrence of a band gap has been investigated for the binary Laves structures and their constituent large- and small-sphere substructures. It was recently shown that these Laves structures give the possibility to fabricate the diamond and pyrochlore structures by self-organization. The comparison of the two calculation methods opens the possibility to study the validity and the convergence of the results, which have been an issue for diamond-related structures in the past. The KKR calculations systematically give a lower value for the gap width than the plane-wave calculations. This difference can partly be ascribed to a convergence issue in the plane-wave code when a contact point of two spheres coincides with the grid.

Clan-structured migration and phenotypic differentiation in the Jirels of Nepal.

PubMed

Williams-Blangero, S

1989-04-01

This paper examines the impact of clan-structured migration on the between-village differentiation of the Jirels, a tribal population of eastern Nepal. The Jirel population is geographically restricted to nine villages, all of which were sampled to some extent for this study. Data on five head measurements, stature, and digital ridge counts are utilized to illustrate the patterns of phenotypic variation. Multivariate statistical techniques are used to assess the extent to which clan membership and associated patterns of marital exchange influence the population structure of the Jirels. The phenotypic characteristics of randomly generated migrant sets are compared to those of the observed clan-structured sets, demonstrating the clan-related phenotypic nonrandomness of migrants. The results indicate that clan-structured migration may significantly influence the amount of between-village variation. Clan structure may be a significant factor in determining patterns of variation and should not be ignored in studies of microdifferentiation in tribal populations.

Two-dimensional finite-element analyses of simulated rotor-fragment impacts against rings and beams compared with experiments

NASA Technical Reports Server (NTRS)

Stagliano, T. R.; Witmer, E. A.; Rodal, J. J. A.

1979-01-01

Finite element modeling alternatives as well as the utility and limitations of the two dimensional structural response computer code CIVM-JET 4B for predicting the transient, large deflection, elastic plastic, structural responses of two dimensional beam and/or ring structures which are subjected to rigid fragment impact were investigated. The applicability of the CIVM-JET 4B analysis and code for the prediction of steel containment ring response to impact by complex deformable fragments from a trihub burst of a T58 turbine rotor was studied. Dimensional analysis considerations were used in a parametric examination of data from engine rotor burst containment experiments and data from sphere beam impact experiments. The use of the CIVM-JET 4B computer code for making parametric structural response studies on both fragment-containment structure and fragment-deflector structure was illustrated. Modifications to the analysis/computation procedure were developed to alleviate restrictions.

Functional and structural abnormalities associated with empathy in patients with schizophrenia: An fMRI and VBM study

PubMed Central

Singh, Sadhana; Modi, Shilpi; Goyal, Satnam; Kaur, Prabhjot; Singh, Namita; Bhatia, Triptish; Deshpande, Smita N; Khushu, Subash

2016-01-01

Empathy deficit is a core feature of schizophrenia which may lead to social dysfunction. The present study was carried out to investigate functional and structural abnormalities associated with empathy in patients with schizophrenia using functional magnetic resonance imaging (fMRI) and voxel-based morphometry (VBM). A sample of 14 schizophrenia patients and 14 healthy control subjects matched for age, sex and education were examined with structural high-resolution T1-weighted MRI; fMRI images were obtained during empathy task in the same session. The analysis was carried out using SPM8 software. On behavioural assessment, schizophrenic patients (83.00±29.04) showed less scores for sadness compared to healthy controls (128.70±22.26) (p<0.001). fMRI results also showed reduced clusters of activation in the bilateral fusiform gyrus, left lingual gyrus, left middle and inferior occipital gyrus in schizophrenic subjects as compared to controls during empathy task. In the same brain areas, VBM results also showed reduced grey and white matter volumes. The present study provides an evidence for an association between structural alterations and disturbed functional brain activation during empathy task in persons affected with schizophrenia. These findings suggest a biological basis for social cognition deficits in schizophrenics. PMID:25963262

Functional and structural abnormalities associated with empathy in patients with schizophrenia: An fMRI and VBM study.

PubMed

Singh, Sadhana; Modi, Shilpi; Goyal, Satnam; Kaur, Prabhjot; Singh, Namita; Bhatia, Triptish; Deshpande, Smita N; Khushu, Subash

2015-06-01

Empathy deficit is a core feature of schizophrenia which may lead to social dysfunction. The present study was carried out to investigate functional and structural abnormalities associated with empathy in patients with schizophrenia using functional magnetic resonance imaging (fMRI) and voxel-based morphometry (VBM). A sample of 14 schizophrenia patients and 14 healthy control subjects matched for age, sex and education were examined with structural highresolution T1-weighted MRI; fMRI images were obtained during empathy task in the same session. The analysis was carried out using SPM8 software. On behavioural assessment, schizophrenic patients (83.00+-29.04) showed less scores for sadness compared to healthy controls (128.70+-22.26) (p less than 0.001). fMRI results also showed reduced clusters of activation in the bilateral fusiform gyrus, left lingual gyrus, left middle and inferior occipital gyrus in schizophrenic subjects as compared to controls during empathy task. In the same brain areas, VBM results also showed reduced grey and white matter volumes. The present study provides an evidence for an association between structural alterations and disturbed functional brain activation during empathy task in persons affected with schizophrenia. These findings suggest a biological basis for social cognition deficits in schizophrenics.

Swift heavy ion induced structural and luminescence characterization of Y₂O₃:Eu³⁺ phosphor: a comparative study.

PubMed

Som, S; Sharma, S K; Lochab, S P

2014-08-01

We report a comparative study on structural and thermoluminescence modifications of Y2O3:Eu(3+) phosphor induced by 150 MeV Ni(7+), 120 MeV Ag(9+) and 110 MeV Au(8+) swift heavy ions (SHI) in the fluence range 1 × 10(11) to 1 × 10(13) ions/cm(2). X-Ray diffraction and transition electron microscopy studies confirm the loss of crystallinity of the phosphors after ion irradiation, which is greater in the case of Au ion irradiation. Structural refinement using the Rietveld method yields the various structural parameters of ion-irradiated phosphors. Thermoluminescence glow curves of ion-irradiated phosphors show a small shift in the position of the peaks, along with an increase in intensity with ion fluence. Stopping range of ions in Matter (SRIM) calculations were performed to correlate the change in thermoluminescence properties of various ion-irradiated phosphors. It shows that the defects created by 110 MeV Au(8+) ions are greater in number. Trapping parameters of ion-irradiated phosphors were calculated from thermoluminescence data using various glow curve analysis methods. Copyright © 2013 John Wiley & Sons, Ltd.

The Prediction of Consumer Buying Intentions: A Comparative Study of the Predictive Efficacy of Two Attitudinal Models. Faculty Working Paper No. 234.

ERIC Educational Resources Information Center

Bhagat, Rabi S.; And Others

The role of attitudes in the conduct of buyer behavior is examined in the context of two competitive models of attitude structure and attitude-behavior relationship. Specifically, the objectives of the study were to compare the Fishbein and Sheth models on the criteria of predictive as well as cross validities. Data on both the models were…

The Evaluation of Argument Mapping as a Learning Tool: Comparing the Effects of Map Reading versus Text Reading on Comprehension and Recall of Arguments

ERIC Educational Resources Information Center

Dwyer, Christopher P.; Hogan, Michael J.; Stewart, Ian

2010-01-01

The current study compared the effects on comprehension and memory of learning via text versus learning via argument map. Argument mapping is a method of diagrammatic representation of arguments designed to simplify the reading of an argument structure and allow for easy assimilation of core propositions and relations. In the current study, 400…

Normative Velopharyngeal Data in Infants: Implications for Treatment of Cleft Palate.

PubMed

Schenck, Graham C; Perry, Jamie L; Fang, Xiangming

2016-09-01

Identifying normative data related to velopharyngeal muscles and structures may have clinical significance for infants born with cleft palate, especially as they relate to selection of surgical intervention and postsurgical outcomes. Previous studies suggest that patients whose anatomy postsurgically is dissimilar to that of their normative counterparts are at risk for hypernasal speech. However, studies have not documented what constitutes "normal" anatomy for the clinically relevant population-that is, the infant population. The purpose of this study is to examine a magnetic resonance imaging database (n = 29) related to normative velopharyngeal structures and provide a preliminary comparison to 2 selected patients with repaired cleft palate. Twenty-nine healthy infants between 9 and 23 months of age (mean = 15.2 months) with normal craniofacial and velopharyngeal anatomy were recruited to participate in this study. Normative data were compared to 2 infants with repaired cleft palate between 13 and 15 months of age (mean = 14 months). Quantitative craniometric and velopharyngeal measures from the sagittal and oblique coronal image planes were collected. Variables of interest included: levator muscle, velar, and craniometric measures. Females demonstrated significantly larger intravelar segments compared with males. White infants demonstrated significantly larger levator muscles compared to non-white infants. Infants with repaired cleft palate demonstrated increased overall levator muscle length and levator extravelar length compared with infants with normal velopharyngeal anatomy.Data from the present study provide a normative database for future investigators to utilize as a comparative tool when evaluating infants with normal and abnormal velopharyngeal anatomy.

Structural prediction and comparative docking studies of psychrophilic β- Galactosidase with lactose, ONPG and PNPG against its counter parts of mesophilic and thermophilic enzymes.

PubMed

Kumar, Ponnada Suresh; Pulicherla, Kk; Ghosh, Mrinmoy; Kumar, Anmol; Rao, Krs Sambasiva

2011-01-01

Enzymes from psychrophiles catalyze the reactions at low temperatures with higher specific activity. Among all the psychrophilic enzymes produced, cold active β-galactosidase from marine psychrophiles revalorizes a new arena in numerous areas at industrial level. The hydrolysis of lactose in to glucose and galactose by cold active β-galactosidase offers a new promising approach in removal of lactose from milk to overcome the problem of lactose intolerance. Herein we propose, a 3D structure of cold active β-galactosidase enzyme sourced from Pseudoalteromonas haloplanktis by using Modeler 9v8 and best model was developed having 88% of favourable region in ramachandran plot. Modelling was followed by docking studies with the help of Auto dock 4.0 against the three substrates lactose, ONPG and PNPG. In addition, comparative docking studies were also performed for the 3D model of psychrophilic β-galactosidase with mesophilic and thermophilic enzymes. Docking studies revealed that binding affinity of enzyme towards the three different substrates is more for psychrophilic enzyme when compared with mesophilic and thermophilic enzymes. It indicates that the enzyme has high specific activity at low temperature when compared with mesophilic and thermophilic enzymes.