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Sample records for adaptive physicochemical structure

  1. Structural, physicochemical characterization and antimicrobial ...

    Indian Academy of Sciences (India)

    Abstract. Tetraaqua bismaleato iron(II) [Fe(C4H3O4)2(H2O)4], (1) is a new synthetic antimicrobial agent. Thermal analysis shows that the dehydration of the compound occurs in agreement with the structure. The sin- gle crystal salt crystallizes in the triclinic space group P-1 with a = 5.171(2) Å, b = 7.309(3) Å, c = 9.731(3).

  2. Structural, physicochemical characterization and antimicrobial ...

    Indian Academy of Sciences (India)

    Tetraaqua bismaleato iron(II) [Fe(C4H3O4)2 (H2O)4], (1) is a new synthetic antimicrobial agent. Thermal analysis shows that the dehydration of the compound occurs in agreement with the structure. The single crystal salt crystallizes in the triclinic space group -1 with = 5.171(2) Å, = 7.309(3) Å, = 9.731(3) Å, ...

  3. Structural Adaptation

    Science.gov (United States)

    Crowley, Julianne; Titmus, Morgan

    2016-01-01

    This article explores an alternative conception held by high school and first-year university biology students regarding the structure of the left and right ventricles of the heart and the significance of the left ventricular wall being thicker than the right. The left ventricular wall of the heart is thicker than the right ventricular wall due to…

  4. Physicochemical properties and interfacial adaptation of root canal sealers.

    Science.gov (United States)

    Cañadas, Piedad S; Berástegui, Ester; Gaton-Hernández, Patrícia; Silva, Léa A B; Leite, Giselle A; Silva, Roberto S

    2014-01-01

    This study compared the physicochemical properties and interfacial adaptation to canal walls of Endo-CPM-Sealer, Sealapex and Activ GP with the well-established AH Plus sealer. The following analyses were performed: radiopacity, pH variation and solubility using samples of each material and scanning electron microscopy of root-filled bovine incisors to evaluate the interfacial adaptation. Data were analyzed by the parametric and no-parametric tests (α=0.05). All materials were in accordance with the ANSI/ADA requirements for radiopacity. Endo-CPM-Sealer presented the lowest radiopacity values and AH Plus was the most radiopaque sealer (p=0.0001). Except for ActiV GP, which was acidic, all other sealers had basic chemical nature and released hydroxyl ions. Regarding solubility, all materials met the ANSI/ADA recommendations, with no statistically significant difference between the sealers (p=0.0834). AH Plus presented the best adaptation to canal walls in the middle (p=0.0023) and apical (p=0.0012) thirds, while the sealers Activ GP and Endo-CPM-Sealer had poor adaptation to the canal walls. All sealers, except for ActiV GP, were alkaline and all of them fulfilled the ANSI/ADA requirements for radiopacity and solubility. Regarding the interfacial adaptation, AH Plus was superior to the others considering the adaptation to the bovine root canal walls.

  5. Structural and physicochemical properties of polar lipids from thermophilic archaea.

    Science.gov (United States)

    Ulrih, Natasa Poklar; Gmajner, Dejan; Raspor, Peter

    2009-08-01

    The essential general features required for lipid membranes of extremophilic archaea to fulfill biological functions are that they are in the liquid crystalline phase and have extremely low permeability of solutes that is much less temperature sensitive due to a lack of lipid-phase transition and highly branched isoprenoid chains. Many accumulated data indicate that the organism's response to extremely low pH is the opposite of that to high temperature. The high temperature adaptation does not require the tetraether lipids, while the adaptation of thermophiles to acidic environment requires the tetraether polar lipids. The presence of cyclopentane rings and the role of polar heads are not so straightforward regarding the correlations between fluidity and permeability of the lipid membrane. Due to the unique lipid structures and properties of archaeal lipids, they are a valuable resource in the development of novel biotechnological processes. This microreview focuses primarily on structural and physicochemical properties of polar lipids of (hyper)thermophilic archaea.

  6. Adaptive structures flight experiments

    Science.gov (United States)

    Martin, Maurice

    The topics are presented in viewgraph form and include the following: adaptive structures flight experiments; enhanced resolution using active vibration suppression; Advanced Controls Technology Experiment (ACTEX); ACTEX program status; ACTEX-2; ACTEX-2 program status; modular control patch; STRV-1b Cryocooler Vibration Suppression Experiment; STRV-1b program status; Precision Optical Bench Experiment (PROBE); Clementine Spacecraft Configuration; TECHSAT all-composite spacecraft; Inexpensive Structures and Materials Flight Experiment (INFLEX); and INFLEX program status.

  7. Adaptive building skin structures

    International Nuclear Information System (INIS)

    Del Grosso, A E; Basso, P

    2010-01-01

    The concept of adaptive and morphing structures has gained considerable attention in the recent years in many fields of engineering. In civil engineering very few practical applications are reported to date however. Non-conventional structural concepts like deployable, inflatable and morphing structures may indeed provide innovative solutions to some of the problems that the construction industry is being called to face. To give some examples, searches for low-energy consumption or even energy-harvesting green buildings are amongst such problems. This paper first presents a review of the above problems and technologies, which shows how the solution to these problems requires a multidisciplinary approach, involving the integration of architectural and engineering disciplines. The discussion continues with the presentation of a possible application of two adaptive and dynamically morphing structures which are proposed for the realization of an acoustic envelope. The core of the two applications is the use of a novel optimization process which leads the search for optimal solutions by means of an evolutionary technique while the compatibility of the resulting configurations of the adaptive envelope is ensured by the virtual force density method

  8. Physicochemical, structural and induced ferromagnetic properties of ...

    Indian Academy of Sciences (India)

    structure. Next, the synthesised precursor powder was ther- mally decomposed by calcination at ∼800. ◦. C for ∼2 h in order to obtain the final product of CdO crystalline structure product. It must be mentioned here that by thermochemistry analysis it was found [13] that during the decomposition of. CdCl2·H2O to CdO, it lost ...

  9. Physicochemical, structural and induced ferromagnetic properties of ...

    Indian Academy of Sciences (India)

    methods by which we can control their structural defects is doping with foreign metallic ions. It was found experimen- tally that doping of TCOs with some metallic ions could increase the concentration of carriers and/or improve the con- ductivity [2]. Besides, the doping process could generate extra exotic properties in TCOs, ...

  10. Structures and physicochemical properties of molecular aggregates of lipids

    International Nuclear Information System (INIS)

    Iwahashi, Makio

    2005-01-01

    Structures and physicochemical properties of lipids such as fatty acids, alcohols, acylglycerols and steroids in their two- or three-dimensional states were studied through the measurements of surface pressure (π), surface-molecular area (A), vapor-pressure osmosis, radioactivity (R), self-diffusion coefficient (D), density, viscosity, near-infrared spectroscopy (NIR), 13 C-NMR spin-lattice relaxation time (T 1 ), ESR, SEM, DSC, X-ray diffraction and small-angle neutron scattering (SANS). Following results are obtained: (1) π-A and R-A relationships indicate that the explanation, being widely believed, of the reaction occurred in the oleic acid or the trioleylglycerol monolayer on the aqueous KMnO 4 solution is incorrect. (2) By using the LB film of 3 H-labelled fatty acid, the upper limit of the neutrino mass was determined. In addition, by using the LB film of 14 C-labelled fatty acid, a new type of crystal-transformation process was found, in which fatty-acid crystal transforms from its unstable state to its stable one by the transfer of the fatty acid molecules through the vapor phase. (3) Fatty acids always exist as their dimers in their liquid state and mostly in non-polar solvents; the dimers are the units of the molecular movements in the molten liquid and in solvents. T 1 results clearly showed the internal molecular movements of the dimers. In addition, D and SANS results indicated that two different kinds of fatty acids in their binary mixture make only each homodimers. (4) Furthermore, the study on the liquid structure of fatty acids such as cis-6-, cis-9-, cis-11-, trans-9-octadecenoic acids and stearic acid indicated that these fatty-acid dimers construct the clusters resemble to the smectic-liquid crystal in the liquid state. The clusters determine the physicochemical properties of the liquid of the fatty acid. (author)

  11. Structural heart adaptations in triathletes.

    Science.gov (United States)

    Claessens, C; Claessens, P; Bloemen, H; Claessens, M; Verbanck, M; Fagard, R; Claessens, J

    1999-12-01

    To perform a triathlon in aerobic conditions, a variety of cardiovascular, haemodynamic and metabolic adaptations are required. The heart is the central concern and also the most important limiting factor. In this study we investigate the structural and functional heart adaptations of a group of triathletes. A group of 52 male triathletes was divided into 4 subgroups in function of their athletic results and compared with a control group of 22 healthy, very active but no athletic men. The groups had comparable anthropometric and general physical characteristics. Very significant differences in cardiac structure and cardiac function were observed between the groups. In the triathletes, we registered distinct signs of significantly mixed eccentric and concentric hypertrophy. Unlike the findings in a pathological left ventricular hypertrophy, the diastolic left ventricular function in triathletes was completely normal and even better than in the control group. The late passive diastolic filling period of the triathlete, in particular, seemed to have specific characteristics. The comparison between the subgroups of triathletes shows us that genetic factors probably play an important role in the cardiac adaptations in triathletes. In our opinion the "athletic heart" in triathletes is not a specific "physiological entity" but is a transitional phase to a dilated hypertrophic cardiomyopathy. Our study yields some arguments for the following proposition: "People are born as elite athletes, with specific characteristics of the left ventricle and with a specifically supernormal diastolic left ventricular function."

  12. Improving protein fold recognition and structural class prediction accuracies using physicochemical properties of amino acids.

    Science.gov (United States)

    Raicar, Gaurav; Saini, Harsh; Dehzangi, Abdollah; Lal, Sunil; Sharma, Alok

    2016-08-07

    Predicting the three-dimensional (3-D) structure of a protein is an important task in the field of bioinformatics and biological sciences. However, directly predicting the 3-D structure from the primary structure is hard to achieve. Therefore, predicting the fold or structural class of a protein sequence is generally used as an intermediate step in determining the protein's 3-D structure. For protein fold recognition (PFR) and structural class prediction (SCP), two steps are required - feature extraction step and classification step. Feature extraction techniques generally utilize syntactical-based information, evolutionary-based information and physicochemical-based information to extract features. In this study, we explore the importance of utilizing the physicochemical properties of amino acids for improving PFR and SCP accuracies. For this, we propose a Forward Consecutive Search (FCS) scheme which aims to strategically select physicochemical attributes that will supplement the existing feature extraction techniques for PFR and SCP. An exhaustive search is conducted on all the existing 544 physicochemical attributes using the proposed FCS scheme and a subset of physicochemical attributes is identified. Features extracted from these selected attributes are then combined with existing syntactical-based and evolutionary-based features, to show an improvement in the recognition and prediction performance on benchmark datasets. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Physico-Chemical and Structural Properties of DeNOx and SO2 Oxidation Catalysts

    DEFF Research Database (Denmark)

    Masters, Stephen Grenville; Oehlers, Cord; Nielsen, Kurt

    1996-01-01

    Commercial catalysts for NOx removal and SO2 oxidation and their model systems have been investigated by spectroscopic, thermal, electrochemical and X-ray methods. Structural information on the vanadium complexes and compounds as well as physico-chemical properties for catalyst model systems have...

  14. Physico-chemical properties and cytotoxic effects of sugar-based surfactants: Impact of structural variations.

    Science.gov (United States)

    Lu, Biao; Vayssade, Muriel; Miao, Yong; Chagnault, Vincent; Grand, Eric; Wadouachi, Anne; Postel, Denis; Drelich, Audrey; Egles, Christophe; Pezron, Isabelle

    2016-09-01

    Surfactants derived from the biorefinery process can present interesting surface-active properties, low cytotoxicity, high biocompatibility and biodegradability. They are therefore considered as potential sustainable substitutes to currently used petroleum-based surfactants. To better understand and anticipate their performances, structure-property relationships need to be carefully investigated. For this reason, we applied a multidisciplinary approach to systematically explore the effect of subtle structural variations on both physico-chemical properties and biological effects. Four sugar-based surfactants, each with an eight carbon alkyl chain bound to a glucose or maltose head group by an amide linkage, were synthesized and evaluated together along with two commercially available standard surfactants. Physico-chemical properties including solubility, Krafft point, surface-tension lowering and critical micellar concentration (CMC) in water and biological medium were explored. Cytotoxicity evaluation by measuring proliferation index and metabolic activity against dermal fibroblasts showed that all surfactants studied may induce cell death at low concentrations (below their CMC). Results revealed significant differences in both physico-chemical properties and cytotoxic effects depending on molecule structural features, such as the position of the linkage on the sugar head-group, or the orientation of the amide linkage. Furthermore, the cytotoxic response increased with the reduction of surfactant CMC. This study underscores the relevance of a methodical and multidisciplinary approach that enables the consideration of surfactant solution properties when applied to biological materials. Overall, our results will contribute to a better understanding of the concomitant impact of surfactant structure at physico-chemical and biological levels. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Landscape structure and the speed of adaptation

    International Nuclear Information System (INIS)

    Claudino, Elder S.; Campos, Paulo R.A.

    2014-01-01

    The role of fragmentation in the adaptive process is addressed. We investigate how landscape structure affects the speed of adaptation in a spatially structured population model. As models of fragmented landscapes, here we simulate the percolation maps and the fractal landscapes. In the latter the degree of spatial autocorrelation can be suited. We verified that fragmentation can effectively affect the adaptive process. The examination of the fixation rates and speed of adaptation discloses the dichotomy exhibited by percolation maps and fractal landscapes. In the latter, there is a smooth change in the pace of the adaptation process, as the landscapes become more aggregated higher fixation rates and speed of adaptation are obtained. On the other hand, in random percolation the geometry of the percolating cluster matters. Thus, the scenario depends on whether the system is below or above the percolation threshold. - Highlights: • The role of fragmentation on the adaptive process is addressed. • Our approach makes the linkage between population genetics and landscape ecology. • Fragmentation affects gene flow and thus influences the speed of adaptation. • The level of clumping determines how the speed of adaptation is influenced

  16. Instrumental methods and techniques for structural and physicochemical characterization of biomaterials and bone tissue: A review.

    Science.gov (United States)

    Mitić, Žarko; Stolić, Aleksandra; Stojanović, Sanja; Najman, Stevo; Ignjatović, Nenad; Nikolić, Goran; Trajanović, Miroslav

    2017-10-01

    A review of recent advances in instrumental methods and techniques for structural and physicochemical characterization of biomaterials and bone tissue is presented in this paper. In recent years, biomaterials attracted great attention primarily because of the wide range of biomedical applications. This paper focuses on the practical aspects of instrumental methods and techniques that were most often applied (X-ray methods, vibrational spectroscopy (IR and Raman), magnetic-resonance spectroscopy (NMR and ESR), mass spectrometry (MS), atomic absorption spectrometry (AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES), thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM)) in the structural investigation and physicochemical characterization of biomaterials and bone tissue. The application of some other physicochemical methods was also discussed. Hands-on information is provided about these valuable research tools, emphasizing practical aspects such as typical measurement conditions, their limitations and advantages, interpretation of results and practical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. The first report of the physicochemical structure of chitin isolated from Hermetia illucens.

    Science.gov (United States)

    Waśko, Adam; Bulak, Piotr; Polak-Berecka, Magdalena; Nowak, Katarzyna; Polakowski, Cezary; Bieganowski, Andrzej

    2016-11-01

    This is the first report on the physicochemical properties of chitin obtained from larvae and imagoes of black soldier flies (Hermetia illucens). Scanning electron microscopy revealed differences in surface morphologies of the two types of chitin. The crystalline index values of chitins from adult flies and larvae were 24.9% and 35%, respectively. This is a trait that differentiates these biopolymers from chitins extracted from other sources described so far. X-ray diffraction patterns and IR spectroscopy revealed that both types of samples of chitin were in an α crystalline form. Also, the results of elemental analysis, thermal stabilities and FTIR spectroscopy of the chitins from larvae and adults of H. illucens were similar, which points to a general similarity in their physicochemical structure. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Effect of γ-irradiation on the physicochemical properties and structure of fish myofibrillar proteins

    Science.gov (United States)

    Shi, Yan; Li, Ru-yi; Tu, Zong-cai; Ma, Da; Wang, Hui; Huang, Xiao-qin; He, Na

    2015-04-01

    The influence of γ-irradiation on physicochemical properties and structures of myofibrillar protein from grass crap exposed to dose up to 10 kGy was investigated. Irradiated samples exhibited decreased emulsifying property and increased surface hydrophobicity. Increasing dose resulted in decreasing free and total sulphydryl groups, decreasing myosin heavy chains in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns. This study demonstrated that γ-irradiation decreased the myofibrillar protein ordered structure and generated the crosslinking and provided a possible reference for the identification of irradiated fish products.

  19. A modular approach to adaptive structures.

    Science.gov (United States)

    Pagitz, Markus; Pagitz, Manuel; Hühne, Christian

    2014-10-07

    A remarkable property of nastic, shape changing plants is their complete fusion between actuators and structure. This is achieved by combining a large number of cells whose geometry, internal pressures and material properties are optimized for a given set of target shapes and stiffness requirements. An advantage of such a fusion is that cell walls are prestressed by cell pressures which increases, decreases the overall structural stiffness, weight. Inspired by the nastic movement of plants, Pagitz et al (2012 Bioinspir. Biomim. 7) published a novel concept for pressure actuated cellular structures. This article extends previous work by introducing a modular approach to adaptive structures. An algorithm that breaks down any continuous target shapes into a small number of standardized modules is presented. Furthermore it is shown how cytoskeletons within each cell enhance the properties of adaptive modules. An adaptive passenger seat and an aircrafts leading, trailing edge is used to demonstrate the potential of a modular approach.

  20. Simulation of Adaptive Kinetic Architectural Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning

    2010-01-01

    to obtain the control forces that must be known in order to control the shape of a real variable geometry truss structure. An experimental test of the of the shape control approach has been implemented using VGT truss structure and a low-cost data acquisition system based on the open-source Arduino......This project deals with shape control of kinetic structures within the field of adaptable architecture. Here a variable geometry truss cantilever structure is analyzed using MATLAB/SIMULINK and the multibody dynamic software MSC Adams. Active shape control of a structure requires that the kinematic...

  1. Population structure and adaptation in fishes

    DEFF Research Database (Denmark)

    Limborg, Morten

    . Comprehensive genetic analyses on the small pelagic fish European sprat (Sprattus sprattus) revealed significant population structure throughout its distribution with an overall pattern of reduced connectivity across environmental transition zones. Population structure reflected both historical separations over......Marine fishes represent a valuable resource for the global economy and food consumption. Accordingly, many species experience high levels of exploitation necessitating effective management plans. However, long term sustainability may be jeopardized from insufficient knowledge about intra......-specific population structure and adaptive divergence. The large population sizes and high migration rates common to most marine fishes impede the differentiating effect of genetic drift, having led to expectations of no population structure and that the occurrence of local adaptation should be rare in these species...

  2. Disciplined structured communications with disciplined runtime adaptation

    NARCIS (Netherlands)

    Di Giusto, Cinzia; Perez, Jorge A.

    2015-01-01

    Session types offer a powerful type-theoretic foundation for the analysis of structured communications, as commonly found in service-oriented systems. They are defined upon core programming calculi which offer only limited support for expressing requirements related to runtime adaptation. This is

  3. Adaptive Origami for Efficiently Folded Structures

    Science.gov (United States)

    2016-02-01

    AFRL-RQ-WP-TR-2016-0020 ADAPTIVE ORIGAMI FOR EFFICIENTLY FOLDED STRUCTURES James J. Joo and Greg Reich Design and Analysis Branch... ORIGAMI FOR EFFICIENTLY FOLDED STRUCTURES 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) James J...NOTES PA Case Number: 88ABW-2016-0843; Clearance Date: 25 February 2016. 14. ABSTRACT Origami , the art of paper folding, transforms a flat sheet into

  4. Adaptive, tolerant and efficient composite structures

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, Martin; Sinapius, Michael (eds.) [German Aerospace Center DLR, Braunschweig (Germany). Inst. of Composite Structures and Adaptive Systems

    2013-07-01

    Polymer composites offer the possibility for functional integration since the material is produced simultaneously with the product. The efficiency of composite structures raises through functional integration. The specific production processes of composites offer the possibility to improve and to integrate more functions thus making the structure more valuable. Passive functions can be improved by combination of different materials from nano to macro scale, i.e. strength, toughness, bearing strength, compression after impact properties or production tolerances. Active functions can be realized by smart materials, i.e. morphing, active vibration control, active structure acoustic control or structure health monitoring. The basis is a comprehensive understanding of materials, simulation, design methods, production technologies and adaptronics. These disciplines together deliver advanced lightweight solutions for applications ranging from mechanical engineering to vehicles, airframe and space structures along the complete process chain. The book provides basics as well as inspiring ideas for engineers working in the field of adaptive, tolerant and robust composite structures.

  5. Categorization of nano-structured titanium dioxide according to physicochemical characteristics and pulmonary toxicity

    Directory of Open Access Journals (Sweden)

    Naoki Hashizume

    Full Text Available A potentially useful means of predicting the pulmonary risk posed by new forms of nano-structured titanium dioxide (nano-TiO2 is to use the associations between the physicochemical properties and pulmonary toxicity of characterized forms of TiO2. In the present study, we conducted intratracheal administration studies in rats to clarify the associations between the physicochemical characteristics of seven characterized forms of TiO2 and their acute or subacute pulmonary inflammatory toxicity. Examination of the associations between the physicochemical characteristics of the TiO2 and the pulmonary inflammatory responses they induced revealed (1 that differences in the crystallinity or shape of the TiO2 particles were not associated with the acute pulmonary inflammatory response; (2 that particle size was associated with the acute pulmonary inflammatory response; and (3 that TiO2 particles coated with Al(OH3 induced a greater pulmonary inflammatory response than did non-coated particles. We separated the seven TiO2 into two groups: a group containing the six TiO2 with no surface coating and a group containing the one TiO2 with a surface coating. Intratracheal administration to rats of TiO2 from the first group (i.e., non-coated TiO2 induced only acute pulmonary inflammatory responses, and within this group, the acute pulmonary inflammatory response was equivalent when the particle size was the same, regardless of crystallinity or shape. In contrast, intratracheal administration to rats of the TiO2 from the second group (i.e., the coated TiO2 induced a more severe, subacute pulmonary inflammatory response compared with that produced by the non-coated TiO2. Since alteration of the pulmonary inflammatory response by surface treatment may depend on the coating material used, the pulmonary toxicities of coated TiO2 need to be further evaluated. Overall, the present results demonstrate that physicochemical properties may be useful for predicting the

  6. Effects of citric acid esterification on digestibility, structural and physicochemical properties of cassava starch.

    Science.gov (United States)

    Mei, Ji-Qiang; Zhou, Da-Nian; Jin, Zheng-Yu; Xu, Xue-Ming; Chen, Han-Qing

    2015-11-15

    In this study, citric acid was used to react with cassava starch in order to compare the digestibility, structural and physicochemical properties of citrate starch samples. The results indicated that citric acid esterification treatment significantly increased the content of resistant starch (RS) in starch samples. The swelling power and solubility of citrate starch samples were lower than those of native starch. Compared with native starch, a new peak at 1724 cm(-1) was appeared in all citrate starch samples, and crystalline peaks of all starch citrates became much smaller or even disappeared. Differential scanning calorimetry results indicated that the endothermic peak of citrate starches gradually shrank or even disappeared. Moreover, the citrate starch gels exhibited better freeze-thaw stability. These results suggested that citric acid esterification induced structural changes in cassava starch significantly affected its digestibility and it could be a potential method for the preparation of RS with thermal stability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Supramolecular structure of jackfruit seed starch and its relationship with digestibility and physicochemical properties.

    Science.gov (United States)

    Chen, Jin; Liang, Yi; Li, Xiaoxi; Chen, Ling; Xie, Fengwei

    2016-10-05

    The influence of supramolecular structure on the physicochemical properties and digestibility of jackfruit seed starch (JSS) were investigated. Compared with maize and cassava starches (MS and CS), JSS had smaller granules and higher amylose content (JSS: 24.90%; CS: 16.68%; and MS: 22.42%), which contributed to higher gelatinization temperature (To: 81.11°C) and setback viscosity (548.9mPas). From scanning electron microscopy, the digestion of JSS was observed mainly at the granule surface. Due to its higher crystallinity (JSS: 30.6%; CS: 30.3%; and MS: 27.4%) and more ordered semi-crystalline lamellae, JSS had a high RS content (74.26%) and melting enthalpy (19.61J/g). In other words, the supramolecular structure of JSS extensively determined its digestibility and resistance to heat and mechanical shear treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Structured emulsions as butter substitutes: effects on physicochemical and sensory attributes of shortbread cookies.

    Science.gov (United States)

    Curti, Elena; Federici, Enrico; Diantom, Agoura; Carini, Eleonora; Pizzigalli, Emanuele; Wu Symon, Veronica; Pellegrini, Nicoletta; Vittadini, Elena

    2018-01-24

    Reformulation of foods products to reduce total and saturated fats while maintaining acceptable structure, texture and mouthfeel poses an important challenge to the food industry. In this work, the use of structured emulsions (fibre-induced oil-in-water biphasic systems with reduced total and saturated fats) is proposed to replace butter in shortbread cookies. Use of structured emulsions resulted in softer dough that was still workable using a traditional process. Shortbread cookies containing structured emulsions were harder and paler than the butter control but had a significantly reduced saturated fat content. They also received promising scores in the sensory analysis in terms of texture and overall acceptability, despite the butter product still being the preferred sample. The results of this study indicated that structured emulsions represent a good solution to produce nutritionally improved shortbreads. Optimization of the structured emulsion formulation can provide further improvement of the nutritional, sensory and physicochemical properties of shortbread cookies. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  9. Characterization of electronic structure and physicochemical properties of antiparasitic nifurtimox analogues: A theoretical study

    Science.gov (United States)

    Soriano-Correa, Catalina; Raya, A.; Esquivel, Rodolfo O.

    American trypanosomiasis, also known as Chagas' disease, is caused by Trypanosoma cruzi (T. cruzi). It is well known that trypanosomes, and particularly T. cruzi, are highly sensitive towards oxidative stress, i.e., to compounds than are able to produce free radicals. Generally, nifurtimox (NFX) and benznidazol are most effective in the acute phase of the disease; therefore, nitroheterocycles constitute good models to design other nitrocompounds with specific biological characteristics. Thus, we have performed an ab initio study at the Hartree-Fock and Density Functional Theory levels of theory of several NFX analogues recently synthesized, to characterize them by obtaining their electronic, structural, and physicochemical properties, which might be linked to the observed antichagasic activity. The antitrypanosomal activity scale previously reported for the NFX analogues studied in this work is in good agreement with our theoretical results, from which we can conclude that the activity seems to be related to the reactivity along with the acidity observed for the most active molecules.

  10. Role of peroxynitrite induced structural changes on H2B histone by physicochemical method.

    Science.gov (United States)

    Khan, M Asad; Alam, Khursheed; Dixit, Kiran; Rizvi, M Moshahid A

    2016-01-01

    Histones are small highly conserved cationic proteins which bind DNA and remain confined in the nucleus. These histones are quite vulnerable to oxidizing and nitrating agents. Peroxynitrite is a powerful oxidant and nitrating agent present in the biological system. In this study, peroxynitrite-induced nitration and oxidation of H2B was assessed by various physicochemical techniques. The carbonyl content and dityrosine were markedly elevated in peroxynitrite-modified H2B histone as compared to the native histone. Cross-linking of H2B was evident on polyacrylamide gel electrophoresis. 3-Nitrotyrosine was present only in peroxynitrite-modified H2B revealed by HPLC. The results showed that peroxynitrite-mediated nitration and oxidation in H2B histone exhibited hyperchromicity, decrease of tyrosine fluorescence accompanied by increase in ANS-binding specific fluorescence, loss of β-sheet structure, appearance of new peak in FT-IR, increase in melting temperature and also loss of α-helix to produce a partially folded structure in comparison to intrinsically disordered structure of native H2B histone. We concluded that the H2B histone, a constituent of core histones, is highly sensitive to peroxynitrite and can adopt different structures under nitrosative and oxidative stress in order to protect the packaged DNA from the deleterious insult of peroxynitrite. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Physico-Chemical and Structural Interpretation of Discrete Derivative Indices on N-Tuples Atoms

    Science.gov (United States)

    Martínez-Santiago, Oscar; Marrero-Ponce, Yovani; Barigye, Stephen J.; Le Thi Thu, Huong; Torres, F. Javier; Zambrano, Cesar H.; Muñiz Olite, Jorge L.; Cruz-Monteagudo, Maykel; Vivas-Reyes, Ricardo; Vázquez Infante, Liliana; Artiles Martínez, Luis M.

    2016-01-01

    This report examines the interpretation of the Graph Derivative Indices (GDIs) from three different perspectives (i.e., in structural, steric and electronic terms). It is found that the individual vertex frequencies may be expressed in terms of the geometrical and electronic reactivity of the atoms and bonds, respectively. On the other hand, it is demonstrated that the GDIs are sensitive to progressive structural modifications in terms of: size, ramifications, electronic richness, conjugation effects and molecular symmetry. Moreover, it is observed that the GDIs quantify the interaction capacity among molecules and codify information on the activation entropy. A structure property relationship study reveals that there exists a direct correspondence between the individual frequencies of atoms and Hückel’s Free Valence, as well as between the atomic GDIs and the chemical shift in NMR, which collectively validates the theory that these indices codify steric and electronic information of the atoms in a molecule. Taking in consideration the regularity and coherence found in experiments performed with the GDIs, it is possible to say that GDIs possess plausible interpretation in structural and physicochemical terms. PMID:27240357

  12. Effect of Spirulina addition on the physicochemical and structural properties of extruded snacks

    Directory of Open Access Journals (Sweden)

    Bárbara Franco LUCAS

    Full Text Available Abstract Nowadays the demand for practical food like snacks increases worldwide, however the nutritional value in most these formulations is reduced. Due to its chemical composition with high protein concentration, the microalga Spirulina has been used on the production of enriched foods. The present study aimed to evaluate the effects of Spirulina sp. LEB 18 addition on snacks formulations and extrusion conditions on the physicochemical and structural properties of snacks. Protein concentration and physical properties such as expansion index, bulk density, hardness, water absorption index, water solubility index and color were determined. The results showed that the addition of Spirulina sp. LEB 18, temperature in the last zone of the extruder and feed moisture influenced the product responses. The increase in feed moisture increased the hardness, bulk density and water absorption index of the snacks. Higher concentrations of microalga produced snacks with higher protein content, total color difference (ΔE and compact structure. The addition of 2.6% Spirulina produced snacks with up to 11.3% protein and with adequate physical and structural properties for consumption. Thus, snacks containing Spirulina are an alternative to the demand for healthy food of practical consumption.

  13. Adapting Bayes Network Structures to Non-stationary Domains

    DEFF Research Database (Denmark)

    Nielsen, Søren Holbech; Nielsen, Thomas Dyhre

    2008-01-01

    When an incremental structural learning method gradually modifies a Bayesian network (BN) structure to fit a sequential stream of observations, we call the process structural adaptation. Structural adaptation is useful when the learner is set to work in an unknown environment, where a BN is gradu......When an incremental structural learning method gradually modifies a Bayesian network (BN) structure to fit a sequential stream of observations, we call the process structural adaptation. Structural adaptation is useful when the learner is set to work in an unknown environment, where a BN...

  14. Structural and physicochemical properties of lotus seed starch treated with ultra-high pressure.

    Science.gov (United States)

    Guo, Zebin; Zeng, Shaoxiao; Lu, Xu; Zhou, Meiling; Zheng, Mingjing; Zheng, Baodong

    2015-11-01

    Aqueous lotus seed starch suspensions (15%, w/w) were subjected to ultra-high pressure treatment (UHP, 100-600 MPa) for 30 min. The effects of UHP treatment on the structural and physicochemical properties of starch were investigated. The SEM and laser diffraction particle size analysis revealed that UHP treatment affected the shape and size distribution of starch granules. The morphological structure of starch was completely destroyed at 600 MPa, indicating complete gelatinization. Analysis of HPSEC-MALLS-RI suggested that the dispersity index of UHP-treated starch were decreased from 1.28 to 1.11. According to XRD analyses, UHP treatment converted native starch (C-type) into a B-type pattern. The swelling power and solubility presented a significant decrease at 85 and 95 °C, but opposite trends were found at 55-75 °C. The DSC results indicated a reduction in gelatinization temperatures and enthalpy with increasing pressure treatment. The RVA viscograms revealed that UHP-treated starch showed a decreased breakdown and setback viscosity, reflecting lower retrogradation tendency compared to native starch. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Structural and physicochemical characterization of pyridine derivative salts of anti-inflammatory drugs

    Science.gov (United States)

    Nechipadappu, Sunil Kumar; Trivedi, Darshak R.

    2017-08-01

    Salts of common anti-inflammatory drugs mefenamic acid (MFA), tolfenamic acid (TFA) and naproxen (NPX) with various pyridine derivatives (4-amino pyridine (4AP), 4-dimethylaminopyridine (DMAP) and 2-amino pyridine (2AP)) were synthesized by crystal engineering approach based on the pKa values of API's and the salt former. All the salts were characterized systematically by various spectroscopic methods including FT-IR and 1H NMR and the crystal structure was determined by single-crystal X-ray diffraction techniques (SCXRD). DMAP salt of NPX and 2AP salts of MFA and TFA were not obtained in the salt screening experiments. All the molecular salts exhibited 1:1 molecular stoichiometry in the asymmetric unit and except NPX-2AP salt, all the molecular salts included a water molecule in the crystal lattice. Physicochemical and structural properties between drug-drug molecular salts of MFA-4AP, TFA-4AP and NPX-4AP have been evaluated and it was found that these molecular salts were found to be stable for a time period of six months at ambient condition and further hydration of molecular salts were not observed even at accelerated humid conditions (∼75% RH). It was found that 4AP salts of MFA and TFA and DMAP salts of MFA and TFA are isostructural.

  16. Adaptive optics for structured illumination microscopy.

    Science.gov (United States)

    Débarre, Delphine; Botcherby, Edward J; Booth, Martin J; Wilson, Tony

    2008-06-23

    We implement wave front sensor-less adaptive optics in a structured illumination microscope. We investigate how the image formation process in this type of microscope is affected by aberrations. It is found that aberrations can be classified into two groups, those that affect imaging of the illumination pattern and those that have no influence on this pattern. We derive a set of aberration modes ideally suited to this application and use these modes as the basis for an efficient aberration correction scheme. Each mode is corrected independently through the sequential optimisation of an image quality metric. Aberration corrected imaging is demonstrated using fixed fluorescent specimens. Images are further improved using differential aberration imaging for reduction of background fluorescence.

  17. Structure Sensitive Hashing With Adaptive Product Quantization.

    Science.gov (United States)

    Liu, Xianglong; Du, Bowen; Deng, Cheng; Liu, Ming; Lang, Bo

    2016-10-01

    Hashing has been proved as an attractive solution to approximate nearest neighbor search, owing to its theoretical guarantee and computational efficiency. Though most of prior hashing algorithms can achieve low memory and computation consumption by pursuing compact hash codes, however, they are still far beyond the capability of learning discriminative hash functions from the data with complex inherent structure among them. To address this issue, in this paper, we propose a structure sensitive hashing based on cluster prototypes, which explicitly exploits both global and local structures. An alternating optimization algorithm, respectively, minimizing the quantization loss and spectral embedding loss, is presented to simultaneously discover the cluster prototypes for each hash function, and optimally assign unique binary codes to them satisfying the affinity alignment between them. For hash codes of a desired length, an adaptive bit assignment is further appended to the product quantization of the subspaces, approximating the Hamming distances and meanwhile balancing the variance among hash functions. Experimental results on four large-scale benchmarks CIFAR-10, NUS-WIDE, SIFT1M, and GIST1M demonstrate that our approach significantly outperforms state-of-the-art hashing methods in terms of semantic and metric neighbor search.

  18. STRUCTURAL AND PHYSICOCHEMICAL SURFACE-PROPERTIES OF SERRATIA-MARCESCENS STRAINS

    NARCIS (Netherlands)

    VANDERMEI, HC; COWAN, MM; GENET, MJ; ROUXHET, PG; BUSSCHER, HJ

    1992-01-01

    Serratia marcescens is an important pathogen with noteworthy hydrophobicity characteristics as assessed by microbial adhesion to hydrocarbons. However, the present knowledge on the surface characteristics of S. marcescens strains does not include physicochemical properties relevant for adhesion such

  19. Adapting Bayes Network Structures to Non-stationary Domains

    DEFF Research Database (Denmark)

    Nielsen, Søren Holbech; Nielsen, Thomas Dyhre

    2006-01-01

    When an incremental structural learning method gradually modifies a Bayesian network (BN) structure to fit observations, as they are read from a database, we call the process structural adaptation. Structural adaptation is useful when the learner is set to work in an unknown environment, where a BN...

  20. Structural characterisation, physicochemical properties and antioxidant activity of polysaccharide from Lilium lancifolium Thunb.

    Science.gov (United States)

    Gao, Jie; Zhang, Ting; Jin, Zheng-Yu; Xu, Xue-Ming; Wang, Jun-Hui; Zha, Xue-Qiang; Chen, Han-Qing

    2015-02-15

    A novel polysaccharide fraction (LP2-1) was isolated and purified from the edible bulbs of Lilium lancifolium Thunb. by DEAE cellulose chromatography and Sephacryl S-400 size-exclusion chromatography. The structural characterisation, physicochemical properties and antioxidant activity of LP2-1 were investigated. The results showed that LP2-1 had an average molecular weight of approximately 8.52×10(3)kDa and was mainly composed of l-rhamnopyranose, d-arabinofuranose, d-glucopyranose and d-galactopyranose in the molar ratio of 1.88:2.13:1.00:2.50, and major functional groups of LP2-1 were COO and OH. The viscoelastic properties of LP2-1 systems exhibited a gel-like behaviour, with storage modulus higher than loss modulus, and both moduli increased with increasing Ca(2+) concentration. In addition, LP2-1 had DPPH and hydroxyl radicals scavenging activities, and also had the strong reducing power and chelating activity on ferrous ion. These results suggest that LP2-1 has good antioxidant activity and can be used in food industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Structural and physicochemical characteristics of starch from sugar cane and sweet sorghum stalks.

    Science.gov (United States)

    Alves, Fernanda Viginotti; Polesi, Luís Fernando; Aguiar, Cláudio Lima; Sarmento, Silene Bruder Silveira

    2014-10-13

    The starch present in sugar cane and sorghum juice has been considered a problem to the sugar industry. The objective of this work was to study the structural and physicochemical characteristics of the starch present in sugar cane and sweet sorghum. Sugar cane and sweet sorghum starches presented small granules (maximum 5.9 and 7.9 μm), A-type diffraction pattern, high degree of relative crystallinity (44.4 and 42.0%), and low amylose content (17.5 and 16.4%), respectively. Sugar cane starch presented more uniformity in granule shape and size, more homogeneity in amylose chain length, higher number of long lateral chains of amylopectin, and higher susceptibility to enzymatic digestion. Besides being in higher amount in the juice, sweet sorghum starch presented lower values for thermal properties of gelatinization, as well as higher swelling factor, which can cause more problems during processing. Additional studies are needed to evaluate the variety and maturity influence on these properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Effects of gamma radiation on microbial, physicochemical, and structural properties of whey protein model system.

    Science.gov (United States)

    Wang, X B; Wang, C N; Zhang, Y C; Liu, T T; Lv, J P; Shen, X; Guo, M R

    2018-03-21

    Gamma radiation has been used in food processing for many years, though it has certain effects on food components. Whey protein solutions (10%/30%, wt/vol) were treated with gamma radiation at various dosages (10-25 kGy) and evaluated for microbial changes in the solutions and physicochemical and structural changes of whey proteins. Whey protein solutions after gamma radiation showed substantially lower populations of all viable microorganisms than those of controls. The 10% whey protein solution treated at radiation of 20 or 25 kGy remained sterile for up to 4 wk at room temperature. Gamma radiation increased viscosity and turbidity and decreased soluble nitrogen of whey protein solutions compared to nonradiated control samples regardless of radiation dosage. Nonreducing sodium dodecyl sulfate-PAGE suggested that whey proteins under gamma radiation treatment formed aggregates with high molecular weights. Reducing sodium dodecyl sulfate-PAGE showed that disulfide bonds played a role in gamma radiation-induced whey protein cross-linking. Scanning and transmission electron microscopy micrographs exhibited large aggregates of whey proteins after gamma radiation treatment. Results suggested that gamma radiation could be applied to whey protein solution for purposes of reducing microbial counts and cross-linking protein molecules. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. On the structural and physicochemical properties of gamma irradiated UHMWPE/silane hybrid

    International Nuclear Information System (INIS)

    Shafiq, Muhammad; Mehmood, Malik Sajjad; Yasin, Tariq

    2013-01-01

    This study has been carried to investigate the influence of gamma rays on the structural and physicochemical properties of UHMWPE/silane hybrid. UHMWPE was mixed with vinyltriethoxysilane (VTES) and compression molded sheets were irradiated at different doses of gamma rays. Fourier transform infrared spectroscopy indicated the formation of siloxane linkages in hybrids, which were found to be shifted towards lower wave number upon irradiation. The X-ray diffraction patterns showed significant increase in the percentage crystallinity of hybrid upon gamma irradiation, especially at 65 kGy absorbed dose. Scanning electron micrographs showed good consolidation and compaction with no surface defects. Moreover, the rough topography was changed to smooth ripple-like appearance upon γ-irradiation. Thermal analysis revealed that irradiated hybrids exhibited higher onset thermal degradation temperature, peak melting temperature, and crystalline lamellae thickness compared with the water treated hybrid. In addition, the tensile testing confirmed an increase of 41% and 133% in yield strength and Young's modulus in 100 kGy irradiated hybrid respectively than that of water treated hybrid. We hope that the irradiated UHMWPE/silane hybrids can be used in various high-strength applications such as total joint replacements, pickers for textile machinery, lining for coal chutes and dump trucks. - Highlights: • UHMWPE/silane hybrids have been prepared and irradiated using gamma rays. • The structural analysis revealed the formation siloxane linkages in the hybrid. • The crystallinity, thermal stability and mechanical properties of hybrids were improved with irradiation. • The irradiated hybrids can be used in various high-strength applications

  4. Physico-chemical, structural, pasting and thermal properties of starches of fourteen Himalayan rice cultivars.

    Science.gov (United States)

    Gani, Adil; Ashwar, Bilal Ahmad; Akhter, Gazalla; Shah, Asima; Wani, Idrees Ahmed; Masoodi, Farooq Ahmad

    2017-02-01

    Starch of fourteen rice cultivars grown in Himalayan region were evaluated for physico-chemical, structural, pasting and thermal properties. The rice cultivars selected showed a wide variation in apparent amylose content (AAC), ranging between 10.76%-26.87%, highest in CH-1039 and lowest in SKAU-292 starch. There were ten low, three intermediate and one high AAC rice. Resistant starch content varied significantly among the rice cultivars, ranging from 6.00% to 19.60%. Generally, high ACC starches presented high contents of resistant starch. Water absorption capacity (80.10-130.32%), swelling (5.73-9.61g/g) and solubility (0.037-0.090g/g) indices varied significantly among the rice cultivars. The rice starch granule morphology showed polyhedral or irregular shapes and granular sizes in the range of 1.8-6.7μm in different rice starches. Pasting profile of starch varied significantly among the rice cultivars, probably due to variations in their AAC. Thermal properties of the starches ranged considerably among different rice cultivars: onset temperature of gelatinization, T o (58.25-72.49°C), peak temperature of gelatinization, T p (69.93-93.26°C), conclusion temperature of gelatinization, T c (97.28±8.28-112.16°C) and gelatinization enthalpy ΔH G (14.29-29.63J/g). The ATR-FTIR spectroscopy of rice starches identified most of the α-1→4 glucosidic linkages within the absorption bands of 1149-1023cm -1 . Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Structural, physicochemical, antioxidant and antitumor property of an acidic polysaccharide from Polygonum multiflorum.

    Science.gov (United States)

    Zhu, Weili; Xue, Xiaoping; Zhang, Zhanjun

    2017-03-01

    In this study, the structural characterization, physicochemical property, antioxidant and antitumor activity of an acidic polysaccharide (APS) from Polygonum multiflorum were investigated. Monosaccharide composition analysis showed APS was composed of arabinose, rhamnose, galactose and galacturonic acid in the molar ratio of 1.23:1.32:1.48:1.00. The presence of uronic acid was also confirmed by the bands at 1740, 1645 and 1425cm -1 on Fourier transform-infrared spectroscopy. Methylation and nuclear magnetic resonance analyses showed APS was mainly composed by the residues of →5)-α-l-Araf-(1→, →3)-β-d-Galp-(1→, →3,6)-β-d-Galp-(1→, →4)-α-d-GalAp-(1→ and →2)-α-l-Rhap-(1→ in the backbone. The non-reducing terminal α-l-Araf-(1→ was probably attached to the O-6 position of →3,6)-β-d-Galp-(1→ residues. Besides, APS exhibited rod-like and flaky shapes with rough surface. The initial decomposition of APS occurred at 172°C, and the rapidest weight loss rate of APS appeared at 320°C. Antioxidant activity assay showed the DPPH radical scavenging activity of APS was 67.5% at 1mg/mL. At the concentration of 400μg/mL, the antiproliferation activities of APS against HepG-2 and BGC-823 cells were 65.28% and 51.57%, respectively. Our results suggested APS could be a potential antioxidant and antitumor agent. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Towards Computerized Adaptive Assessment Based on Structured Tasks

    NARCIS (Netherlands)

    Tvarožek, Jozef; Kravcik, Milos; Bieliková, Mária

    2008-01-01

    Tvarožek, J., Kravčík, M., & Bieliková, M. (2008). Towards Computerized Adaptive Assessment Based on Structured Tasks. In W. Nejdl et al. (Eds.), Adaptive Hypermedia and Adaptive Web-Based Systems (pp. 224-234). Springer Berlin / Heidelberg.

  7. Temporal Structure of Adaptation to Disability.

    Science.gov (United States)

    Livneh, Hanoch; Antonak, Richard F.

    1991-01-01

    Used cross-sectional design to collect data on phases of adaptation to disability as measured by the Reactions to Impairment and Disability Inventory among 112 inpatients and 92 outpatients at rehabilitation facilities. Results generally support the existence of a psychosocial adaptation process to physical disability. Incongruities between the…

  8. Optimal structure of metaplasticity for adaptive learning.

    Directory of Open Access Journals (Sweden)

    Peyman Khorsand

    2017-06-01

    Full Text Available Learning from reward feedback in a changing environment requires a high degree of adaptability, yet the precise estimation of reward information demands slow updates. In the framework of estimating reward probability, here we investigated how this tradeoff between adaptability and precision can be mitigated via metaplasticity, i.e. synaptic changes that do not always alter synaptic efficacy. Using the mean-field and Monte Carlo simulations we identified 'superior' metaplastic models that can substantially overcome the adaptability-precision tradeoff. These models can achieve both adaptability and precision by forming two separate sets of meta-states: reservoirs and buffers. Synapses in reservoir meta-states do not change their efficacy upon reward feedback, whereas those in buffer meta-states can change their efficacy. Rapid changes in efficacy are limited to synapses occupying buffers, creating a bottleneck that reduces noise without significantly decreasing adaptability. In contrast, more-populated reservoirs can generate a strong signal without manifesting any observable plasticity. By comparing the behavior of our model and a few competing models during a dynamic probability estimation task, we found that superior metaplastic models perform close to optimally for a wider range of model parameters. Finally, we found that metaplastic models are robust to changes in model parameters and that metaplastic transitions are crucial for adaptive learning since replacing them with graded plastic transitions (transitions that change synaptic efficacy reduces the ability to overcome the adaptability-precision tradeoff. Overall, our results suggest that ubiquitous unreliability of synaptic changes evinces metaplasticity that can provide a robust mechanism for mitigating the tradeoff between adaptability and precision and thus adaptive learning.

  9. Parallel adaptive mesh refinement for electronic structure calculations

    Energy Technology Data Exchange (ETDEWEB)

    Kohn, S.; Weare, J.; Ong, E.; Baden, S.

    1996-12-01

    We have applied structured adaptive mesh refinement techniques to the solution of the LDA equations for electronic structure calculations. Local spatial refinement concentrates memory resources and numerical effort where it is most needed, near the atomic centers and in regions of rapidly varying charge density. The structured grid representation enables us to employ efficient iterative solver techniques such as conjugate gradients with multigrid preconditioning. We have parallelized our solver using an object-oriented adaptive mesh refinement framework.

  10. Adapting Institutional Structure and Culture to Change.

    Science.gov (United States)

    Parilla, Robert E.

    1993-01-01

    Highlights the importance of management in a community college's success. Suggests that adaptive institutions, which identify challenges and create programs through cooperation with their staff and faculty, have a mechanism for continuous quality improvement. Describes Montgomery College's (Maryland) transition from a bureaucratic management…

  11. Effects of heavy metals and soil physicochemical properties on wetland soil microbial biomass and bacterial community structure.

    Science.gov (United States)

    Zhang, Chang; Nie, Shuang; Liang, Jie; Zeng, Guangming; Wu, Haipeng; Hua, Shanshan; Liu, Jiayu; Yuan, Yujie; Xiao, Haibing; Deng, Linjing; Xiang, Hongyu

    2016-07-01

    Heavy metals (HMs) contamination is a serious environmental issue in wetland soil. Understanding the micro ecological characteristic of HMs polluted wetland soil has become a public concern. The goal of this study was to identify the effects of HMs and soil physicochemical properties on soil microorganisms and prioritize some parameters that contributed significantly to soil microbial biomass (SMB) and bacterial community structure. Bacterial community structure was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Relationships between soil environment and microorganisms were analyzed by correlation analysis and redundancy analysis (RDA). The result indicated relationship between SMB and HMs was weaker than SMB and physicochemical properties. The RDA showed all eight parameters explained 74.9% of the variation in the bacterial DGGE profiles. 43.4% (contain the variation shared by Cr, Cd, Pb and Cu) of the variation for bacteria was explained by the four kinds of HMs, demonstrating HMs contamination had a significant influence on the changes of bacterial community structure. Cr solely explained 19.4% (pstructure, and Cd explained 17.5% (pstructure changes. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Geometry control in adaptive truss structures

    Science.gov (United States)

    Ramesh, A. V.; Utku, S.

    1990-01-01

    Forward and inverse kinematics equations are derived for the large geometry maneuver of adaptive trusses. A new algorithm based on higher-order multistep methods is proposed as a means of computing the length control for a described large geometry maneuver. The algorithm is shown to improve in computational speed at least five times over the algorithm presented in an earlier paper. The acceleration in control computation and other features such as varying velocity profiles and curved trajectories are illustrated by simulation results.

  13. Effect of Grinding Methods on Structural, Physicochemical, and Functional Properties of Insoluble Dietary Fiber from Orange Peel

    Directory of Open Access Journals (Sweden)

    Yanlong Liu

    2016-01-01

    Full Text Available This study evaluated the effect of grinding methods (regular laboratory milling, ultra centrifugal rotor milling, and ball milling on structural, physicochemical, and functional properties of insoluble dietary fiber (IDF fraction from orange peel. The results demonstrated that both ultra centrifugal milling and ball milling could effectively decrease average particle size of IDF fraction (81.40 μm and 19.63 μm, resp.. The matrix structure of IDF fraction was destroyed but FTIR structure had no major change after grinding. As particle size decreased, the bulk density and lightness of IDF fraction increased and a redistribution of fiber components from insoluble to soluble fractions was observed. Furthermore, ball milled IDF fraction exhibited significantly higher capacity to retard glucose diffusion and inhibit α-amylase activity (35.09%. This work would give useful insight into effect of grinding methods on properties and functions of orange peel IDF in food industry.

  14. Native and Reconstituted Plasma Lipoproteins in Nanomedicine: Physicochemical Determinants of Nanoparticle Structure, Stability, and Metabolism.

    Science.gov (United States)

    Pownall, Henry J; Rosales, Corina; Gillard, Baiba K; Ferrari, Mauro

    2016-09-01

    Although many acute and chronic diseases are managed via pharmacological means, challenges remain regarding appropriate drug targeting and maintenance of therapeutic levels within target tissues. Advances in nanotechnology will overcome these challenges through the development of lipidic particles, including liposomes, lipoproteins, and reconstituted high-density lipoproteins (rHDL) that are potential carriers of water-soluble, hydrophobic, and amphiphilic molecules. Herein we summarize the properties of human plasma lipoproteins and rHDL, identify the physicochemical determinants of lipid transfer between phospholipid surfaces, and discuss strategies for increasing the plasma half-life of lipoprotein- and liposome-associated molecules.

  15. Physicochemical and Biological Investigation of Different Structures of Carbon Coatings Deposited onto Polyurethane

    Directory of Open Access Journals (Sweden)

    Witold Kaczorowski

    2016-01-01

    Full Text Available The aim of this study was to examine the thrombogenic properties of polyurethane that was surface modified with carbon coatings. Physicochemical properties of manufactured coatings were investigated using transmission electron microscopy (TEM, atomic force microscopy (AFM, X-ray Photoelectron Spectroscopy (XPS, Raman spectroscopy and contact angle measurement methods. Samples were examined by the Impact-R method evaluating the level of platelets activation and adhesion of particular blood cell elements. The analysis of antimicrobial resistance against E. coli colonization and viability of endothelial cells showed that polyurethane modified with use of carbon layers constituted an interesting solution for biomedical application.

  16. Simulation of Adaptive Kinetic Architectural Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning

    2010-01-01

    to obtain the control forces that must be known in order to control the shape of a real variable geometry truss structure. An experimental test of the of the shape control approach has been implemented using VGT truss structure and a low-cost data acquisition system based on the open-source Arduino...

  17. Adaptive, tolerant and efficient composite structures

    CERN Document Server

    Sinapius, Michael

    2013-01-01

    Polymer composites offer the possibility for functional integration since the material is produced simultaneously with the product. The efficiency of composite structures raises through functional integration. The specific production processes of composites offer the possibility to improve and to integrate more functions thus making the structure more valuable. Passive functions can be improved by combination of different materials from nano to macro scale, i.e. strength, toughness, bearing strength, compression after impact properties or production tolerances.  Active functions can be realized by smart materials, i.e. morphing, active vibration control, active structure acoustic control or structure health monitoring. The basis is a comprehensive understanding of materials, simulation, design methods, production technologies and adaptronics. These disciplines together deliver advanced lightweight solutions for applications ranging from mechanical engineering to vehicles, airframe and space structures along ...

  18. Adaptive Distributed Data Structure Management for Parallel CFD Applications

    KAUST Repository

    Frisch, Jerome

    2013-09-01

    Computational fluid dynamics (CFD) simulations require a lot of computing resources in terms of CPU time and memory in order to compute with a reasonable physical accuracy. If only uniformly refined domains are applied, the amount of computing cells is growing rather fast if a certain small resolution is physically required. This can be remedied by applying adaptively refined grids. Unfortunately, due to the adaptive refinement procedures, errors are introduced which have to be taken into account. This paper is focussing on implementation details of the applied adaptive data structure management and a qualitative analysis of the introduced errors by analysing a Poisson problem on the given data structure, which has to be solved in every time step of a CFD analysis. Furthermore an adaptive CFD benchmark example is computed, showing the benefits of an adaptive refinement as well as measurements of parallel data distribution and performance. © 2013 IEEE.

  19. Interactive ion-mediated sap flow regulation in olive and laurel stems: physicochemical characteristics of water transport via the pit structure.

    Directory of Open Access Journals (Sweden)

    Jeongeun Ryu

    Full Text Available Sap water is distributed and utilized through xylem conduits, which are vascular networks of inert pipes important for plant survival. Interestingly, plants can actively regulate water transport using ion-mediated responses and adapt to environmental changes. However, ionic effects on active water transport in vascular plants remain unclear. In this report, the interactive ionic effects on sap transport were systematically investigated for the first time by visualizing the uptake process of ionic solutions of different ion compositions (K+/Ca2+ using synchrotron X-ray and neutron imaging techniques. Ionic solutions with lower K+/Ca2+ ratios induced an increased sap flow rate in stems of Olea europaea L. and Laurus nobilis L. The different ascent rates of ionic solutions depending on K+/Ca2+ ratios at a fixed total concentration increases our understanding of ion-responsiveness in plants from a physicochemical standpoint. Based on these results, effective structural changes in the pit membrane were observed using varying ionic ratios of K+/Ca2+. The formation of electrostatically induced hydrodynamic layers and the ion-responsiveness of hydrogel structures based on Hofmeister series increase our understanding of the mechanism of ion-mediated sap flow control in plants.

  20. Interactive ion-mediated sap flow regulation in olive and laurel stems: physicochemical characteristics of water transport via the pit structure.

    Science.gov (United States)

    Ryu, Jeongeun; Ahn, Sungsook; Kim, Seung-Gon; Kim, TaeJoo; Lee, Sang Joon

    2014-01-01

    Sap water is distributed and utilized through xylem conduits, which are vascular networks of inert pipes important for plant survival. Interestingly, plants can actively regulate water transport using ion-mediated responses and adapt to environmental changes. However, ionic effects on active water transport in vascular plants remain unclear. In this report, the interactive ionic effects on sap transport were systematically investigated for the first time by visualizing the uptake process of ionic solutions of different ion compositions (K+/Ca2+) using synchrotron X-ray and neutron imaging techniques. Ionic solutions with lower K+/Ca2+ ratios induced an increased sap flow rate in stems of Olea europaea L. and Laurus nobilis L. The different ascent rates of ionic solutions depending on K+/Ca2+ ratios at a fixed total concentration increases our understanding of ion-responsiveness in plants from a physicochemical standpoint. Based on these results, effective structural changes in the pit membrane were observed using varying ionic ratios of K+/Ca2+. The formation of electrostatically induced hydrodynamic layers and the ion-responsiveness of hydrogel structures based on Hofmeister series increase our understanding of the mechanism of ion-mediated sap flow control in plants.

  1. Inverse Finite Method Investigation for Adaptive Structures

    Data.gov (United States)

    National Aeronautics and Space Administration — This research project is evaluating an innovative technique that uses fiber optic strain sensors to measure structural deformations and full field strains. An...

  2. A modular approach to adaptive structures

    OpenAIRE

    Pagitz, Markus; Pagitz, Manuel; Hühne, C.

    2014-01-01

    A remarkable property of nastic, shape changing plants is their complete fusion between actuators and structure. This is achieved by combining a large number of cells whose geometry, internal pressures and material properties are optimized for a given set of target shapes and stiffness requirements. An advantage of such a fusion is that cell walls are prestressed by cell pressures which increases, decreases the overall structural stiffness, weight. Inspired by the nastic movement of plants, P...

  3. Modification of structure and physicochemical properties of buckwheat and oat starch by γ-irradiation.

    Science.gov (United States)

    Dar, M Zuhaib; Deepika, Km; Jan, Kulsum; Swer, Tanya L; Kumar, Pradeep; Verma, Ruchi; Verma, Kush; Prakash, Kumar S; Jan, Shumaila; Bashir, Khalid

    2018-03-01

    Effects of gamma irradiation on the physicochemical, rheological and thermal properties of the buckwheat and oat starch were studied. Results revealed that the transition temperature and enthalpy of gelatinization of starch decreased with increase in irradiation dose. Pasting properties (peak, trough, setback, pasting temperature and final viscosity) of both the starches were decreased by gamma irradiation. Gamma irradiation also resulted in the reduction in the per cent crystallinity of the starches. Apparent amylose content and swelling index decreased with increase in dose. However, solubility index was increased by gamma irradiation. No surface fissures were seen in irradiated starches. FTIR spectra pattern did not change by gamma irradiation. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Co-adaptation and the emergence of structure.

    Science.gov (United States)

    Savit, Robert; Riolo, Maria; Riolo, Rick

    2013-01-01

    Co-adaptation (or co-evolution), the parallel feedback process by which agents continuously adapt to the changes induced by the adaptive actions of other agents, is a ubiquitous feature of complex adaptive systems, from eco-systems to economies. We wish to understand which general features of complex systems necessarily follow from the (meta)-dynamics of co-adaptation, and which features depend on the details of particular systems. To begin this project, we present a model of co-adaptation ("The Stigmergy Game") which is designed to be as a priori featureless as possible, in order to help isolate and understand the naked consequences of co-adaptation. In the model, heterogeneous, co-adapting agents, observe, interact with and change the state of an environment. Agents do not, ab initio, directly interact with each other. Agents adapt by choosing among a set of random "strategies," particular to each agent. Each strategy is a complete specification of an agent's actions and payoffs. A priori, all environmental states are equally likely and all strategies have payoffs that sum to zero, so without co-adaptation agents would on average have zero "wealth". Nevertheless, the dynamics of co-adaptation generates a structured environment in which only a subset of environmental states appear with high probability (niches) and in which agents accrue positive wealth. Furthermore, although there are no direct agent-agent interactions, there are induced non-trivial inter-agent interactions mediated by the environment. As a function of the population size and the number of possible environmental states, the system can be in one of three dynamical regions. Implications for a basic understanding of complex adaptive systems are discussed.

  5. Co-adaptation and the emergence of structure.

    Directory of Open Access Journals (Sweden)

    Robert Savit

    Full Text Available Co-adaptation (or co-evolution, the parallel feedback process by which agents continuously adapt to the changes induced by the adaptive actions of other agents, is a ubiquitous feature of complex adaptive systems, from eco-systems to economies. We wish to understand which general features of complex systems necessarily follow from the (meta-dynamics of co-adaptation, and which features depend on the details of particular systems. To begin this project, we present a model of co-adaptation ("The Stigmergy Game" which is designed to be as a priori featureless as possible, in order to help isolate and understand the naked consequences of co-adaptation. In the model, heterogeneous, co-adapting agents, observe, interact with and change the state of an environment. Agents do not, ab initio, directly interact with each other. Agents adapt by choosing among a set of random "strategies," particular to each agent. Each strategy is a complete specification of an agent's actions and payoffs. A priori, all environmental states are equally likely and all strategies have payoffs that sum to zero, so without co-adaptation agents would on average have zero "wealth". Nevertheless, the dynamics of co-adaptation generates a structured environment in which only a subset of environmental states appear with high probability (niches and in which agents accrue positive wealth. Furthermore, although there are no direct agent-agent interactions, there are induced non-trivial inter-agent interactions mediated by the environment. As a function of the population size and the number of possible environmental states, the system can be in one of three dynamical regions. Implications for a basic understanding of complex adaptive systems are discussed.

  6. Exploring the usefulness of key green physicochemical properties: Quantitative structure-activity relationship for solvents from biomass.

    Science.gov (United States)

    Zuriaga, Estefanía; Giner, Beatriz; Ribate, María Pilar; García, Cristina B; Lomba, Laura

    2018-04-01

    In recent decades there has been a growing interest in the development of new solvents from biomass. Some of these new solvents have been classified as green because of their renewable and sustainable source. However, characterization from the ecotoxicological and physicochemical points of view is needed to categorize them as green solvents. We have selected several key physicochemical properties that can reflect environmental features (density, boiling point, critical aggregation concentration, and log p) and explored their usefulness for preliminarily assessing the green character of the studied solvents. Specifically, we have studied several solvents from biomass: lactate family (methyl, ethyl, and butyl lactate), furfural family (furfural, 5-methylfurfural, furfuryl alcohol, and tetrahydrofurfuryl alcohol), and levulinate family (methyl, ethyl, and butyl levulinate). To fill the gaps and complete some toxicity data for the environment, we have measured the ecotoxicity using 2 of the most common and versatile biomodels, bacteria Vibrio fischeri and crustacean Daphnia magna, for furfural- and lactate-derived compounds. The results indicate that solvents from biomass can be categorized as green because their toxicity for the environment is low. Finally, a quantitative structure-activity relationship (QSAR) study was performed with the selected key properties and the ecotoxicological information. Despite the different structure of the chemicals under study, good correlations were found for the studied organisms. It seems that log p and critical aggregation concentration reflect the greatest part of the ecotoxic behavior, whereas density and boiling point cannot reflect toxicity signals. However, these properties are rather useful for assessing the final environmental fate of the studied chemicals. Environ Toxicol Chem 2018;37:1014-1023. © 2017 SETAC. © 2017 SETAC.

  7. Physico-chemical and structural characterization of mucilage isolated from seeds of Diospyros melonoxylon Roxb.

    Directory of Open Access Journals (Sweden)

    Sudarshan Singh

    2014-12-01

    Full Text Available Mucilage was isolated from the seeds of Diospyros melonoxylonRoxb., a plant growing naturally in the forests of India. Various physico-chemical methods like particle analysis, scanning electron microscopy, differential scanning calorimetry, differential thermal analysis, thermogravimetry analysis, molecular weight by gel permeation chromatography, rheometry, elemental analysis, x-ray diffraction spectrometry, zeta potential, fourier transform infrared spectroscopy, 1D(1H and 13C (NMR have been employed to characterize this gum in the present study. Particle analyses suggest that mucilage had particle size in nanometer. SEM analysis suggested that the mucilage had irregular particle size. The glass transition temperature of the gum observed was 78 °C and 74 °C by DSC and DTA respectively. The Thermogravimetry analysis suggested that mucilage had good thermal stability with two stage decomposition. The molecular weight of mucilage was determined to be 8760, by gel permeation chromatography, while the viscosity of mucilage was observed to be 219.1 cP. The XRD pattern of the mucilage indicated a complete amorphous nature. Elemental analysis of the gum revealed specific contents of carbon, hydrogen, nitrogen and sulfur. The major functional groups identified from FT-IR spectrum include 3441 cm-1 (-OH, 1632 cm-1 (-COO-, 1414 cm-1 (-COO- and 1219 cm-1 (-CH3CO. Analysis of mucilage by paper chromatography and 1D NMR indicated the presence of sugars.

  8. Adaptive Control of Truss Structures for Gossamer Spacecraft

    Science.gov (United States)

    Yang, Bong-Jun; Calise, Anthony J.; Craig, James I.; Whorton, Mark S.

    2007-01-01

    Neural network-based adaptive control is considered for active control of a highly flexible truss structure which may be used to support solar sail membranes. The objective is to suppress unwanted vibrations in SAFE (Solar Array Flight Experiment) boom, a test-bed located at NASA. Compared to previous tests that restrained truss structures in planar motion, full three dimensional motions are tested. Experimental results illustrate the potential of adaptive control in compensating for nonlinear actuation and modeling error, and in rejecting external disturbances.

  9. Adaptation of brain functional and structural networks in aging.

    Directory of Open Access Journals (Sweden)

    Annie Lee

    Full Text Available The human brain, especially the prefrontal cortex (PFC, is functionally and anatomically reorganized in order to adapt to neuronal challenges in aging. This study employed structural MRI, resting-state fMRI (rs-fMRI, and high angular resolution diffusion imaging (HARDI, and examined the functional and structural reorganization of the PFC in aging using a Chinese sample of 173 subjects aged from 21 years and above. We found age-related increases in the structural connectivity between the PFC and posterior brain regions. Such findings were partially mediated by age-related increases in the structural connectivity of the occipital lobe within the posterior brain. Based on our findings, it is thought that the PFC reorganization in aging could be partly due to the adaptation to age-related changes in the structural reorganization of the posterior brain. This thus supports the idea derived from task-based fMRI that the PFC reorganization in aging may be adapted to the need of compensation for resolving less distinctive stimulus information from the posterior brain regions. In addition, we found that the structural connectivity of the PFC with the temporal lobe was fully mediated by the temporal cortical thickness, suggesting that the brain morphology plays an important role in the functional and structural reorganization with aging.

  10. Adaptation of brain functional and structural networks in aging.

    Science.gov (United States)

    Lee, Annie; Ratnarajah, Nagulan; Tuan, Ta Anh; Chen, Shen-Hsing Annabel; Qiu, Anqi

    2015-01-01

    The human brain, especially the prefrontal cortex (PFC), is functionally and anatomically reorganized in order to adapt to neuronal challenges in aging. This study employed structural MRI, resting-state fMRI (rs-fMRI), and high angular resolution diffusion imaging (HARDI), and examined the functional and structural reorganization of the PFC in aging using a Chinese sample of 173 subjects aged from 21 years and above. We found age-related increases in the structural connectivity between the PFC and posterior brain regions. Such findings were partially mediated by age-related increases in the structural connectivity of the occipital lobe within the posterior brain. Based on our findings, it is thought that the PFC reorganization in aging could be partly due to the adaptation to age-related changes in the structural reorganization of the posterior brain. This thus supports the idea derived from task-based fMRI that the PFC reorganization in aging may be adapted to the need of compensation for resolving less distinctive stimulus information from the posterior brain regions. In addition, we found that the structural connectivity of the PFC with the temporal lobe was fully mediated by the temporal cortical thickness, suggesting that the brain morphology plays an important role in the functional and structural reorganization with aging.

  11. The physico-chemical properties and structural characteristics of artificial soil for cut slope restoration in Southwestern China

    Science.gov (United States)

    Chen, Shunan; Ai, Xiaoyan; Dong, Tengyun; Li, Binbin; Luo, Ruihong; Ai, Yingwei; Chen, Zhaoqiong; Li, Chuanren

    2016-02-01

    Cut slopes are frequently generated by construction work in hilly areas, and artificial soil is often sprayed onto them to promote ecological rehabilitation. The artificial soil properties are very important for effective management of the slopes. This paper uses fractal and moment methods to characterize soil particle size distribution (PSD) and aggregates composition. The fractal dimension (D) showed linear relationships between clay, silt, and sand contents, with coefficients of determination from 0.843 to 0.875, suggesting that using of D to evaluate the PSD of artificial soils is reasonable. The bias (CS) and peak convex (CE) coefficients showed significant correlations with structure failure rate, moisture content, and total porosity, which validated the moment method to quantitatively describe soil structure. Railway slope (RS) soil has lower organic carbon and soil moisture, and higher pH than natural slope soil. Overall, RS exhibited poor soil structure and physicochemical properties, increasing the risk of soil erosion. Hence, more effective management measures should be adopted to promote the restoration of cut slopes.

  12. Parallel computation of geometry control in adaptive truss structures

    Science.gov (United States)

    Ramesh, A. V.; Utku, S.; Wada, B. K.

    1992-01-01

    The fast computation of geometry control in adaptive truss structures involves two distinct parts: the efficient integration of the inverse kinematic differential equations that govern the geometry control and the fast computation of the Jacobian, which appears on the right-hand-side of the inverse kinematic equations. This paper present an efficient parallel implementation of the Jacobian computation on an MIMD machine. Large speedup from the parallel implementation is obtained, which reduces the Jacobian computation to an O(M-squared/n) procedure on an n-processor machine, where M is the number of members in the adaptive truss. The parallel algorithm given here is a good candidate for on-line geometry control of adaptive structures using attached processors.

  13. Narcissistic Personality Inventory : Structure of the adapted Dutch version

    NARCIS (Netherlands)

    Barelds, Dick P. H.; Dijkstra, Pieternel

    The present study examined the structure of a Dutch adaptation of the 40-item Narcissistic Personality Inventory (Raskin & Terry, 1988) in a community sample (n = 460) and a student sample (n = 515). Altering the response format of the NPI to a Likert-scale had no apparent effect on the responses.

  14. Optimization of cationic lipid mediated gene transfer: structure-function, physico-chemical, and cellular studies.

    Science.gov (United States)

    Carrière, Marie; Tranchant, Isabelle; Niore, Pierre-Antoine; Byk, Gerardo; Mignet, Nathalie; Escriou, Virginie; Scherman, Daniel; Herscovici, Jean

    2002-01-01

    The rationale design aimed at the enhancement of cationic lipid mediated gene transfer is discussed. These improvements are based on the straight evaluation of the structure-activity relationship and on the introduction of new structures. Much attention have been given to the supramolecular structures of the lipid/DNA complexes, to the effect of serum on gene transfer and to the intracellular trafficking of the lipoplexes. Finally new avenue using reducible cationic lipids has been discussed.

  15. Physicochemical and structural characterization of a two-dimensional polymer performed by using the Langmuir-Blodgett technique

    International Nuclear Information System (INIS)

    Lefevre, Didier

    1995-01-01

    This research thesis addresses the physicochemical and structural characterization of two-dimensional polymer made of polymerizable macro-cycles pre-organised in-plane by using the Langmuir-Blodgett technique. Macro-cycles are porphyrins with four acetylenic functions which bind in both plane directions by formation of diacetylenic covalent bonds. These porphyrins are adsorbed under a single layer of dihexadecyl-phosphoric acid to build up a monomer amphiphilic film. The author reports the characterization of the Langmuir film by the study of compression isotherms and by Brewster angle microscopy. Other techniques are used (UV, visible and infrared spectroscopy, Raman spectroscopy) to highlight the polymerization in LB film. X photo-electronic spectroscopy and secondary ion mass spectroscopy are also used. The author reports the study of the orientation of macro-cycles before and after polymerization by using linear dichroism, electronic paramagnetic resonance and X ray diffraction. The in-plane LB film structure is studied by transmission X ray diffraction, atomic force microscopy in correlation with molecular simulation. The two-dimensional feature of the polymer formed at the water surface is highlighted. The membrane is visualized by electronic and optic microscopy, and characterized by EDXS and electronic diffraction [fr

  16. Impact of amylosucrase modification on the structural and physicochemical properties of native and acid-thinned waxy corn starch.

    Science.gov (United States)

    Zhang, Hao; Zhou, Xing; He, Jian; Wang, Tao; Luo, Xiaohu; Wang, Li; Wang, Ren; Chen, Zhengxing

    2017-04-01

    Recombinant amylosucrase from Neisseria polysaccharea was utilized to modify native and acid-thinned starches. The molecular structures and physicochemical properties of modified starches were investigated. Acid-thinned starch displayed much lower viscosity after gelatinization than did the native starch. However, the enzyme exhibited similar catalytic efficiency for both forms of starch. The modified starches had higher proportions of long (DP>33) and intermediate chains (DP 13-33), and X-ray diffraction showed a B-type crystalline structure for all modified starches. With increasing reaction time, the relative crystallinity and endothermic enthalpy of the modified starches gradually decreased, whereas the melting peak temperatures and resistant starch contents increased. Slight differences were observed in thermal parameters, relative crystallinity, and branch chain length distribution between the modified native and acid-thinned starches. Moreover, the digestibility of the modified starches was not affected by acid hydrolysis pretreatment, but was affected by the percentage of intermediate and long chains. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Structure-adaptive sparse denoising for diffusion-tensor MRI.

    Science.gov (United States)

    Bao, Lijun; Robini, Marc; Liu, Wanyu; Zhu, Yuemin

    2013-05-01

    Diffusion tensor magnetic resonance imaging (DT-MRI) is becoming a prospective imaging technique in clinical applications because of its potential for in vivo and non-invasive characterization of tissue organization. However, the acquisition of diffusion-weighted images (DWIs) is often corrupted by noise and artifacts, and the intensity of diffusion-weighted signals is weaker than that of classical magnetic resonance signals. In this paper, we propose a new denoising method for DT-MRI, called structure-adaptive sparse denoising (SASD), which exploits self-similarity in DWIs. We define a similarity measure based on the local mean and on a modified structure-similarity index to find sets of similar patches that are arranged into three-dimensional arrays, and we propose a simple and efficient structure-adaptive window pursuit method to achieve sparse representation of these arrays. The noise component of the resulting structure-adaptive arrays is attenuated by Wiener shrinkage in a transform domain defined by two-dimensional principal component decomposition and Haar transformation. Experiments on both synthetic and real cardiac DT-MRI data show that the proposed SASD algorithm outperforms state-of-the-art methods for denoising images with structural redundancy. Moreover, SASD achieves a good trade-off between image contrast and image smoothness, and our experiments on synthetic data demonstrate that it produces more accurate tensor fields from which biologically relevant metrics can then be computed. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. An adaptive learning control system for large flexible structures

    Science.gov (United States)

    Thau, F. E.

    1985-01-01

    The objective of the research has been to study the design of adaptive/learning control systems for the control of large flexible structures. In the first activity an adaptive/learning control methodology for flexible space structures was investigated. The approach was based on using a modal model of the flexible structure dynamics and an output-error identification scheme to identify modal parameters. In the second activity, a least-squares identification scheme was proposed for estimating both modal parameters and modal-to-actuator and modal-to-sensor shape functions. The technique was applied to experimental data obtained from the NASA Langley beam experiment. In the third activity, a separable nonlinear least-squares approach was developed for estimating the number of excited modes, shape functions, modal parameters, and modal amplitude and velocity time functions for a flexible structure. In the final research activity, a dual-adaptive control strategy was developed for regulating the modal dynamics and identifying modal parameters of a flexible structure. A min-max approach was used for finding an input to provide modal parameter identification while not exceeding reasonable bounds on modal displacement.

  19. Adaptive mutations alter antibody structure and dynamics during affinity maturation.

    Science.gov (United States)

    Adhikary, Ramkrishna; Yu, Wayne; Oda, Masayuki; Walker, Ross C; Chen, Tingjian; Stanfield, Robyn L; Wilson, Ian A; Zimmermann, Jörg; Romesberg, Floyd E

    2015-03-24

    While adaptive mutations can bestow new functions on proteins via the introduction or optimization of reactive centers, or other structural changes, a role for the optimization of protein dynamics also seems likely but has been more difficult to evaluate. Antibody (Ab) affinity maturation is an example of adaptive evolution wherein the adaptive mutations may be identified and Abs may be raised to specific targets that facilitate the characterization of protein dynamics. Here, we report the characterization of three affinity matured Abs that evolved from a common germline precursor to bind the chromophoric antigen (Ag), 8-methoxypyrene-1,3,6-trisulfonate (MPTS). In addition to characterizing the sequence, molecular recognition, and structure of each Ab, we characterized the dynamics of each complex by determining their mechanical response to an applied force via three-pulse photon echo peak shift (3PEPS) spectroscopy and deconvoluting the response into elastic, anelastic, and plastic components. We find that for one Ab, affinity maturation was accomplished via the introduction of a single functional group that mediates a direct contact with MPTS and results in a complex with little anelasticity or plasticity. In the other two cases, more mutations were introduced but none directly contact MPTS, and while their effects on structure are subtle, their effects on anelasticity and plasticity are significant, with the level of plasticity correlated with specificity, suggesting that the optimization of protein dynamics may have contributed to affinity maturation. A similar optimization of structure and dynamics may contribute to the evolution of other proteins.

  20. Adaptations in Electronic Structure Calculations in Heterogeneous Environments

    Energy Technology Data Exchange (ETDEWEB)

    Talamudupula, Sai [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Modern quantum chemistry deals with electronic structure calculations of unprecedented complexity and accuracy. They demand full power of high-performance computing and must be in tune with the given architecture for superior e ciency. To make such applications resourceaware, it is desirable to enable their static and dynamic adaptations using some external software (middleware), which may monitor both system availability and application needs, rather than mix science with system-related calls inside the application. The present work investigates scienti c application interlinking with middleware based on the example of the computational chemistry package GAMESS and middleware NICAN. The existing synchronous model is limited by the possible delays due to the middleware processing time under the sustainable runtime system conditions. Proposed asynchronous and hybrid models aim at overcoming this limitation. When linked with NICAN, the fragment molecular orbital (FMO) method is capable of adapting statically and dynamically its fragment scheduling policy based on the computing platform conditions. Signi cant execution time and throughput gains have been obtained due to such static adaptations when the compute nodes have very di erent core counts. Dynamic adaptations are based on the main memory availability at run time. NICAN prompts FMO to postpone scheduling certain fragments, if there is not enough memory for their immediate execution. Hence, FMO may be able to complete the calculations whereas without such adaptations it aborts.

  1. Peroxynitrite-induced structural perturbations in human IgG: A physicochemical study.

    Science.gov (United States)

    Arfat, Mir Yasir; Arif, Zarina; Chaturvedi, Sumit Kumar; Moinuddin; Alam, Khursheed

    2016-08-01

    IgG is an important defence protein. To exhibit optimum function the molecule must maintain its native structure. Peroxynitrite is a potent oxidizing and nitrating agent produced in vivo under pathophysiological conditions. It can oxidize and/or nitrate various amino acids causing changes in the structure and function of proteins. Such proteins may be involved in the pathogenesis of many inflammatory diseases, including rheumatoid arthritis. In the present work, peroxynitrite-induced structural changes in IgG have been studied by UV-visible, fluorescence, CD, FT-IR, DLS spectroscopy and DSC as well as by SDS-PAGE. Peroxynitrite-modified IgG exhibited hyperchromicity at 280 nm, quenching of tryptophan fluorescence, increase in ANS fluorescence, loss of β-sheet, shift in the positions of amide I and amide II bands, appearance of new peak in FT-IR, attachment of nitro residues and increase in melting temperature, compared to native IgG. Furthermore, peroxynitrite-modified IgG exhibited an additional peak at 420 nm, quenching in tyrosine fluorescence and enhancement in dityrosine fluorescence compared to native IgG. Generation of nitrotyrosine, dityrosine and nitrotryptophan was also observed in peroxynitrite-modified IgG. Gross structural changes in IgG caused by peroxynitrite and observed in vitro may favour autoantibodies induction in vivo under similar conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Engaging stakeholders for adaptive management using structured decision analysis

    Science.gov (United States)

    Irwin, Elise R.; Kathryn, D.; Kennedy, Mickett

    2009-01-01

    Adaptive management is different from other types of management in that it includes all stakeholders (versus only policy makers) in the process, uses resource optimization techniques to evaluate competing objectives, and recognizes and attempts to reduce uncertainty inherent in natural resource systems. Management actions are negotiated by stakeholders, monitored results are compared to predictions of how the system should respond, and management strategies are adjusted in a “monitor-compare-adjust” iterative routine. Many adaptive management projects fail because of the lack of stakeholder identification, engagement, and continued involvement. Primary reasons for this vary but are usually related to either stakeholders not having ownership (or representation) in decision processes or disenfranchisement of stakeholders after adaptive management begins. We present an example in which stakeholders participated fully in adaptive management of a southeastern regulated river. Structured decision analysis was used to define management objectives and stakeholder values and to determine initial flow prescriptions. The process was transparent, and the visual nature of the modeling software allowed stakeholders to see how their interests and values were represented in the decision process. The development of a stakeholder governance structure and communication mechanism has been critical to the success of the project.

  3. Physicochemical conditions, metabolites and community structure of the bacterial microbiota in the gut of wood-feeding cockroaches (Blaberidae: Panesthiinae).

    Science.gov (United States)

    Bauer, Eugen; Lampert, Niclas; Mikaelyan, Aram; Köhler, Tim; Maekawa, Kiyoto; Brune, Andreas

    2015-02-01

    While the gut microbiota of termites and its role in symbiotic digestion have been studied for decades, little is known about the bacteria colonizing the intestinal tract of the distantly related wood-feeding cockroaches (Blaberidae: Panesthiinae). Here, we show that physicochemical gut conditions and microbial fermentation products in the gut of Panesthia angustipennis resemble that of other cockroaches. Microsensor measurements confirmed that all gut compartments were anoxic at the center and had a slightly acidic to neutral pH and a negative redox potential. While acetate dominated in all compartments, lactate and hydrogen accumulated only in the crop. The high, hydrogen-limited rates of methane emission from living cockroaches were in agreement with the restriction of F420-fluorescent methanogens to the hindgut. The gut microbiota of both P. angustipennis and Salganea esakii differed strongly between compartments, with the highest density and diversity in the hindgut, but similarities between homologous compartments of both cockroaches indicated a specificity of the microbiota for their respective habitats. While some lineages were most closely related to the gut microbiota of omnivorous cockroaches and wood- or litter-feeding termites, others have been encountered also in vertebrates, reinforcing the hypothesis that strong environmental selection drives community structure in the cockroach gut. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Physicochemical, structural and thermal properties of oxidized, acetylated and dual-modified common bean (Phaseolus vulgaris L. starch

    Directory of Open Access Journals (Sweden)

    José Pedro WOJEICCHOWSKI

    2018-03-01

    Full Text Available Abstract Common beans are rich in protein and complex carbohydrates that are valuable for the human diet. Starch is the most abundant individual component; however, in its native form it has limited applications and modifications are necessary to overcome technological restrictions. The aim of this study was to evaluate the influence of oxidation, acetylation and dual-modification (oxidation-acetylation on the physicochemical, structural and thermal properties of common bean starch. The degree of substitution of the acetylated starches was compatible with food use. Fourier transform infrared spectra confirmed the acetylation of the bean starch, with a peak at 1,735cm-1. The granules of the bean starch were oval to spherical in shape, with no differences between the native and modified samples. Typical C-type diffraction of legume starches was found. The modified samples showed a reduced relative crystallinity and lower enthalpy change of gelatinization. The oxidized starch showed the highest peak viscosity, hardness, and gel adhesiveness due to the presence of functional groups. An increase in solubility and swelling power was observed, and the oxidized-acetylated starch presented the highest values. The properties of the modified bean starches made them suitable for application in breaded/battered foods, mainly due to improved textural attributes.

  5. Morphological, physico-chemical and structural characterization of mucilage isolated from the seeds of Buchanania lanzan Spreng

    OpenAIRE

    Sudarshan Singh; Sunil B Bothara

    2014-01-01

    Context: Mucilage isolated from the seeds of Buchanania lanzan a wild Indian plant. This mucilage can be commercially exploited, by evaluating physico-chemical properties of this mucilage. Materials and Methods: Various physico-chemical parameter using scanning electron microscopy (SEM), molecular weight, X-ray diffraction (XRD) spectrometry, zeta potential (ZP), Fourier transform infrared (FT-IR) spectroscopy and 1D ( 1 H and 13 C) nuclear magnetic resonance (NMR) have been employed to chara...

  6. Nonlinear vibration with control for flexible and adaptive structures

    CERN Document Server

    Wagg, David

    2015-01-01

    This book provides a comprehensive discussion of nonlinear multi-modal structural vibration problems, and shows how vibration suppression can be applied to such systems by considering a sample set of relevant control techniques. It covers the basic principles of nonlinear vibrations that occur in flexible and/or adaptive structures, with an emphasis on engineering analysis and relevant control techniques. Understanding nonlinear vibrations is becoming increasingly important in a range of engineering applications, particularly in the design of flexible structures such as aircraft, satellites, bridges, and sports stadia. There is an increasing trend towards lighter structures, with increased slenderness, often made of new composite materials and requiring some form of deployment and/or active vibration control. There are also applications in the areas of robotics, mechatronics, micro electrical mechanical systems, non-destructive testing and related disciplines such as structural health monitoring. Two broader ...

  7. Effects of extraction methods and particle size distribution on the structural, physicochemical, and functional properties of dietary fiber from deoiled cumin.

    Science.gov (United States)

    Ma, Meng-Mei; Mu, Tai-Hua

    2016-03-01

    This study evaluated the effects of alkali extraction, enzymatic hydrolysis, shear emulsifying assisted enzymatic hydrolysis, and particle size distribution on the chemical composition and the structural, physicochemical, and functional properties of deoiled cumin dietary fibers (AEDF, EHDF and SEDF). Compared to AEDF and EHDF, SEDF had the highest total dietary fiber, crystalline regions, water swelling capacity (6.79-7.98ml/g), oil adsorption capacity (6.12-7.25%), α-amylase activity inhibition ratio (14.79-21.84%), glucose adsorption capacity (2.02-60.86%), and bile acid retardation index (16.34-50.08%). DFs sieved with mesh sizes >80 exhibited better physicochemical and functional properties than unsieved DFs. The physicochemical properties of sieved DFs improved with increasing sieve mesh sizes (40-120), but decreased with sieve mesh sizes >120, while the functional properties increased with increasing sieve mesh sizes. SEDF sieved with mesh sizes 100-150 can be used as functional ingredients due to its excellent physicochemical and functional properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Block-structured Adaptive Mesh Refinement - Theory, Implementation and Application

    Directory of Open Access Journals (Sweden)

    Deiterding Ralf

    2011-12-01

    Full Text Available Structured adaptive mesh refinement (SAMR techniques can enable cutting-edge simulations of problems governed by conservation laws. Focusing on the strictly hyperbolic case, these notes explain all algorithmic and mathematical details of a technically relevant implementation tailored for distributed memory computers. An overview of the background of commonly used finite volume discretizations for gas dynamics is included and typical benchmarks to quantify accuracy and performance of the dynamically adaptive code are discussed. Large-scale simulations of shock-induced realistic combustion in non-Cartesian geometry and shock-driven fluid-structure interaction with fully coupled dynamic boundary motion demonstrate the applicability of the discussed techniques for complex scenarios.

  9. Low sat-structured fats enriched in α-linolenic acid: physicochemical properties and crystallization characteristics.

    Science.gov (United States)

    Stahl, Marcella Aparecida; Buscato, Monise Helen Masuchi; Grimaldi, Renato; Cardoso, Lisandro Pavie; Ribeiro, Ana Paula Badan

    2017-10-01

    This work sought to obtain and evaluate zero trans-fat reduced in saturated fatty acids, with higher content of unsaturated fatty acids. Palm oil (PO) was used as the reference of zero trans lipid base. Different amounts of linseed oil (LO) were added to PO, obtaining the following blends: 100:0; 80:20; 60:40; 40:60; 20:80 and 0:100 of PO:LO (w/w%), respectively. These blends were added to fully hydrogenated soybean oil (FHSO) as the crystallization modifying agent, and to sorbitan monostearate (SMS) as the structuring element, both at a proportion of 3% to build the structured fractions. The control and the structured blends were evaluated for fatty acid composition, solid fat content, consistency, crystallization kinetics, thermal behavior, microstructure and polymorphism. With the addition of LO to the PO, an increase of up to 80% was observed in the content of alpha-linolenic acid and a reduction of saturated fatty acids to 47% in the blends. FHSO and SMS offered thermal resistance to the blends, with relevant changes in the crystallization kinetics and microstructure, affecting macroscopic characteristics with the increase in consistence. It was possible to obtain a lipid formulation with features of plasticity and enhanced nutritional quality, compatible with several food applications.

  10. Shape tuning of adaptive structures for MEMS actuator applications

    Science.gov (United States)

    Ma, Zhichun; Lee, Yung-Cheng

    2005-05-01

    This paper describes a systematic shape tuning procedure of adaptive structures for MEMS actuator applications. Due to fabrication process variations, MEMS devices can have different shapes with varied deflections. Such shape variations should be corrected for specific applications. As a result, it is necessary to establish a shape tuning procedure. Finite element modeling and optimization approach were used to minimize the shape variations. The procedure integrated Python programming, ABAQUS, and optimization algorithm for engineering applications. It used the powerful Python scripts programming, the vast library of ABAQUS functions, and a robust preexisting optimization algorithm, NLPQL, which provides more efficient, flexible, and systematic tools for optimization problems. Optimization was used in the adaptive structural designs and the shape tuning procedure after the assembly. Using this approach, three bimorph, gold-on-polysilicon, samples with different initial shapes were studied for shape tuning. The shape was characterized by maximum tip deflection resulting from thermo-mechanical deformations. The standard deviation of the shape variations was reduced from 1.21 to 0.05 μm after tuning. This reduction was verified by experimental data. Another case with ten devices was studied to confirm the effectiveness of the procedure. The standard deviation of the deflections was reduced from 0.81 to 0.02 μm after tuning. These results demonstrated the effectiveness of the optimum procedure for shape tuning. This general-purpose systematic methodology can be applied to adaptive structures for a variety of aerospace applications.

  11. Physical, Physicochemical, Mechanical, and Structural Characterization of Films Based on Gelatin/Glycerol and Carbon Nanotubes

    OpenAIRE

    Israel Sifuentes-Nieves; Rodolfo Rendón-Villalobos; Antonio Jiménez-Aparicio; Brenda Hildeliza Camacho-Díaz; Gustavo Fidel Gutiérrez López; Javier Solorza-Feria

    2015-01-01

    A new method to prepare glycerol/gelatin based films, by doping the film with carbon nanotubes (CNTs) and sodium dodecyl sulfate (SDS), was proposed. SDS was used to disperse CNTs in gelatin/glycerol films as follows: gelatin/glycerol (GG) incubated with equal concentrations of CNT and SDS; GG with 0.001% w/w CNT/SDS; GG with 0.002% CNT/SDS and GG with 0.004% CNT/SDS. Diffractograms of CNT/SDS /glycerol films showed an amorphous structure, being consistent with thermograms involving temperatu...

  12. Structural elucidation and physicochemical properties of an organic NLO crystal: 4-Nitrotoluene-2-sulphonic acid dihydrate

    Science.gov (United States)

    Sangeetha, K.; Guru Prasad, L.; Mathammal, R.

    2018-03-01

    4-nitrotoluene-2-sulphonic acid dihydrate single crystals have been developed using slow evaporation technique in methanol. Lattice parameters of the NTSAD crystal have been calculated and it confirms the grown material. The intermolecular interactions are studied from the 3D Hirshfeld surface analysis and 2D fingerprint plots. The NMR spectral analysis has been carried out to confirm the molecular structure of the grown material. Optical properties have been obtained from UV-VIS spectral analysis and photoluminescence studies. Frequency conversion property of the NTSAD crystal was investigated with the aid of Kurtz and Perry method.

  13. Effects of partial hydrolysis and subsequent cross-linking on wheat gluten physicochemical properties and structure.

    Science.gov (United States)

    Wang, Kaiqiang; Luo, Shuizhong; Cai, Jing; Sun, Qiaoqiao; Zhao, Yanyan; Zhong, Xiyang; Jiang, Shaotong; Zheng, Zhi

    2016-04-15

    The rheological behavior and thermal properties of wheat gluten following partial hydrolysis using Alcalase and subsequent microbial transglutaminase (MTGase) cross-linking were investigated. The wheat gluten storage modulus (G') and thermal denaturation temperature (Tg) were significantly increased from 2.26 kPa and 54.43°C to 7.76 kPa and 57.69°C, respectively, by the combined action of partial hydrolysis (DH 0.187%) and cross-linking. The free SH content, surface hydrophobicity, and secondary structure analysis suggested that an appropriate degree of Alcalase-based hydrolysis allowed the compact wheat gluten structure to unfold, increasing the β-sheet content and surface hydrophobicity. This improved its molecular flexibility and exposed additional glutamine sites for MTGase cross-linking. SEM images showed that a compact 3D network formed, while SDS-PAGE profiles revealed that excessive hydrolysis resulted in high-molecular-weight subunits degrading to smaller peptides, unsuitable for cross-linking. It was also demonstrated that the combination of Alcalase-based partial hydrolysis with MTGase cross-linking might be an effective method for modifying wheat gluten rheological behavior and thermal properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Recrystallization of starches by hydrothermal treatment: digestibility, structural, and physicochemical properties.

    Science.gov (United States)

    Trinh, Khanh Son

    2015-12-01

    Gelatinized starches were recrystallized under hydrothermal treatment and their properties were characterized by X-ray diffractometry, solid-state (13)C cross-polarization and magic-angle spinning nuclear magnetic resonance, differential scanning calorimetry, gel-permeation chromatography, high-performance anion-exchange chromatography using pulsed amperomeric detection, high-performance size-exclusion chromatography with attached multiangle laser light scattering and refractive index detectors, and digestibility analysis. Amylopectin molecules of hylon (V, VII) and water yam starch contained long side-chains with high proportion of fb1 and fb2. Under hydrothermal treatment, the double helix proportion and relative crystallinity significantly increased and reached maxima of water yam (48.7 and 28.2 %, respectively). Except water yam starch, X-ray diffraction pattern of all starches exhibited the evidence of type 2 amylose-lipid complex. Besides, under DSC measurement, potato and hylon starches showed the endotherm of amylose-amylose interaction. The hydrothermal treatment caused the recrystallization resulting in the decrease of RDS, especially in case of hylon and water yam starch. HTT water yam contained highest SDS (48.3 %) and HTT hylon VII contained highest RS (44.5 %). The relationship between structure and digestibility was observed, in which, high amylose content and specific structures of amylopectin molecule were necessary for the production of RS and/or SDS of hydrothermally treated starches.

  15. Polymeric Thin Films for Organic Electronics: Properties and Adaptive Structures

    Directory of Open Access Journals (Sweden)

    Bruno Pignataro

    2013-03-01

    Full Text Available This review deals with the correlation between morphology, structure and performance of organic electronic devices including thin film transistors and solar cells. In particular, we report on solution processed devices going into the role of the 3D supramolecular organization in determining their electronic properties. A selection of case studies from recent literature are reviewed, relying on solution methods for organic thin-film deposition which allow fine control of the supramolecular aggregation of polymers confined at surfaces in nanoscopic layers. A special focus is given to issues exploiting morphological structures stemming from the intrinsic polymeric dynamic adaptation under non-equilibrium conditions.

  16. A chemometric analysis of ligand-induced changes in intrinsic fluorescence of folate binding protein indicates a link between altered conformational structure and physico-chemical characteristics

    DEFF Research Database (Denmark)

    Bruun, Susanne W; Holm, Jan; Hansen, Steen Ingemann

    2009-01-01

    Ligand binding alters the conformational structure and physico-chemical characteristics of bovine folate binding protein (FBP). For the purpose of achieving further information we analyzed ligand (folate and methotrexate)-induced changes in the fluorescence landscape of FBP. Fluorescence excitation...... of folate accords fairly well with the disappearance of strongly hydrophobic tryptophan residues from the solvent-exposed surface of FBP. The PARAFAC has thus proven useful to establish a hitherto unexplained link between parallel changes in conformational structure and physico-chemical characteristics...... of FBP induced by folate binding. Parameters for ligand binding derived from PARAFAC analysis of the fluorescence data were qualitatively and quantitatively similar to those obtained from binding of radiofolate to FBP. Herein, methotrexate exhibited a higher affinity for FBP than in competition...

  17. Parallel Evolution of Chromatin Structure Underlying Metabolic Adaptation.

    Science.gov (United States)

    Cheng, Jian; Guo, Xiaoxian; Cai, Pengli; Cheng, Xiaozhi; Piškur, Jure; Ma, Yanhe; Jiang, Huifeng; Gu, Zhenglong

    2017-11-01

    Parallel evolution occurs when a similar trait emerges in independent evolutionary lineages. Although changes in protein coding and gene transcription have been investigated as underlying mechanisms for parallel evolution, parallel changes in chromatin structure have never been reported. Here, Saccharomyces cerevisiae and a distantly related yeast species, Dekkera bruxellensis, are investigated because both species have independently evolved the capacity of aerobic fermentation. By profiling and comparing genome sequences, transcriptomic landscapes, and chromatin structures, we revealed that parallel changes in nucleosome occupancy in the promoter regions of mitochondria-localized genes led to concerted suppression of mitochondrial functions by glucose, which can explain the metabolic convergence in these two independent yeast species. Further investigation indicated that similar mutational processes in the promoter regions of these genes in the two independent evolutionary lineages underlay the parallel changes in chromatin structure. Our results indicate that, despite several hundred million years of separation, parallel changes in chromatin structure, can be an important adaptation mechanism for different organisms. Due to the important role of chromatin structure changes in regulating gene expression and organism phenotypes, the novel mechanism revealed in this study could be a general phenomenon contributing to parallel adaptation in nature. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Learning Unknown Structure in CRFs via Adaptive Gradient Projection Method

    Directory of Open Access Journals (Sweden)

    Wei Xue

    2016-08-01

    Full Text Available We study the problem of fitting probabilistic graphical models to the given data when the structure is not known. More specifically, we focus on learning unknown structure in conditional random fields, especially learning both the structure and parameters of a conditional random field model simultaneously. To do this, we first formulate the learning problem as a convex minimization problem by adding an l_2-regularization to the node parameters and a group l_1-regularization to the edge parameters, and then a gradient-based projection method is proposed to solve it which combines an adaptive stepsize selection strategy with a nonmonotone line search. Extensive simulation experiments are presented to show the performance of our approach in solving unknown structure learning problems.

  19. Adaptive modal identification of structures with equivariant adaptive separation via independence approach

    Science.gov (United States)

    Amini, Fereidoun; Ghasemi, Vida

    2018-01-01

    An efficient output-only Blind Source Separation (BSS) method was recently introduced for the modal identification of structures. BSS procedures recover a set of independent sources from their unknown linear mixtures when only mixtures are observed. Batch data is required for the separation in traditional blind source separation methods. These algorithms are however unfavorable, as some sets of data are observed one after another. In this paper, an adaptive blind source separation technique - equivariant adaptive separation via independence (EASI) - is introduced to overcome the mentioned disadvantage within the structures. The EASI algorithm is beneficial as it can provide solutions to real time problems, while also update the un-mixing matrix for each step. EASI not only avoids increases in size of the relevant matrices and vectors, but also decreases the analysis time. A synthetic example and a benchmark structure have been used in this paper to better investigate the efficiency of the proposed method. The simulation results demonstrate the effectiveness of the EASI algorithm in on-line identification of modal parameters of structures.

  20. Structural and physicochemical characteristics of a novel water-soluble gum from Lallemantia royleana seed.

    Science.gov (United States)

    Razavi, Seyed Mohammad Ali; Cui, Steve W; Ding, Huihuang

    2016-02-01

    In this study, the structural information (monosaccharide compositions, molecular weight parameters & FTIR analysis), chemical composition (moisture, protein, ash, carbohydrate & uronic acids), rheological properties, and surface activity of Lallemantia royleana seeds mucilage (BSG) were determined. The results showed BSG contains 8.51% (w.b.) moisture, 8.24% (d.b.) ash, 2.71% (d.b.) protein, 75.87% (d.b.) carbohydrate and 20.33% (d.b.) uronic acids. Monosaccharide analysis revealed the presence of arabinose (37.88%), galactose (33.54%), rhamnose (18.44%), xylose (6.02%) and glucose (4.11%) in the BSG polysaccharide. Although BSG had similar molecular weight (1.294×10(6) Da) compared to most seed gums, the intrinsic viscosity (23.06 dL/g) and gyration radius (104.84 nm) were higher. The BSG exhibited a strong shear-thinning behavior (nBSG rheological properties. Dynamic mechanical spectra demonstrated BSG is a typical of weak gel, which its rheological parameters were superior to those of many commercial gums. The FTIR spectra of the BSG polymer showed the presence of carboxyl groups, which may serve as binding sites for ions. BSG exhibited the ability to reduce the surface tension of water at concentrations lower than 0.75%. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Adaptive symbiotic organisms search (SOS algorithm for structural design optimization

    Directory of Open Access Journals (Sweden)

    Ghanshyam G. Tejani

    2016-07-01

    Full Text Available The symbiotic organisms search (SOS algorithm is an effective metaheuristic developed in 2014, which mimics the symbiotic relationship among the living beings, such as mutualism, commensalism, and parasitism, to survive in the ecosystem. In this study, three modified versions of the SOS algorithm are proposed by introducing adaptive benefit factors in the basic SOS algorithm to improve its efficiency. The basic SOS algorithm only considers benefit factors, whereas the proposed variants of the SOS algorithm, consider effective combinations of adaptive benefit factors and benefit factors to study their competence to lay down a good balance between exploration and exploitation of the search space. The proposed algorithms are tested to suit its applications to the engineering structures subjected to dynamic excitation, which may lead to undesirable vibrations. Structure optimization problems become more challenging if the shape and size variables are taken into account along with the frequency. To check the feasibility and effectiveness of the proposed algorithms, six different planar and space trusses are subjected to experimental analysis. The results obtained using the proposed methods are compared with those obtained using other optimization methods well established in the literature. The results reveal that the adaptive SOS algorithm is more reliable and efficient than the basic SOS algorithm and other state-of-the-art algorithms.

  2. Energies and physicochemical properties of cation-π interactions in biological structures.

    Science.gov (United States)

    Du, Qi-Shi; Meng, Jian-Zong; Liao, Si-Ming; Huang, Ri-Bo

    2012-04-01

    The cation-π interactions occur frequently within or between proteins due to six (Phe, Tyr, Trp, Arg, Lys, and His) of the twenty natural amino acids potentially interacting with metallic cations via these interactions. In this study, quantum chemical calculations and molecular orbital (MO) theory are used to study the energies and properties of cation-π interactions in biological structures. The cation-π interactions of H⁺ and Li⁺ are similar to hydrogen bonds and lithium bonds, respectively, in which the small, naked cations H⁺ and Li⁺ are buried deep within the π-electron density of aromatic molecules, forming stable cation-π bonds that are much stronger than the cation-π interactions of other alkali metal cations. The cation-π interactions of metallic cations with atomic masses greater than that of Li⁺ arise mainly from the coordinate bond comprising empty valence atomic orbitals (AOs) of metallic cations and π-MOs of aromatic molecules, though electrostatic interactions may also contribute to the cation-π interaction. The binding strength of cation-π interactions is determined by the charge and types of AOs in the metallic cations. Cation-π interaction energies are distance- and orientation-dependent; energies decrease with the distance (r) and the orientation angle (θ). In solution, the cation-π energies decrease with the increase of the dielectric constant (ɛ) of the solvent; however, solvation has less influence on the H⁺-π and H₃O⁺-π interactions than on interactions with other cations. The conclusions from this study provide useful theoretical insights into the nature of cation-π interactions and may contribute to the development of better force field parameters for describing the molecular dynamics of cation-π interactions within and between proteins. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Direct Adaptive Aircraft Control Using Dynamic Cell Structure Neural Networks

    Science.gov (United States)

    Jorgensen, Charles C.

    1997-01-01

    A Dynamic Cell Structure (DCS) Neural Network was developed which learns topology representing networks (TRNS) of F-15 aircraft aerodynamic stability and control derivatives. The network is integrated into a direct adaptive tracking controller. The combination produces a robust adaptive architecture capable of handling multiple accident and off- nominal flight scenarios. This paper describes the DCS network and modifications to the parameter estimation procedure. The work represents one step towards an integrated real-time reconfiguration control architecture for rapid prototyping of new aircraft designs. Performance was evaluated using three off-line benchmarks and on-line nonlinear Virtual Reality simulation. Flight control was evaluated under scenarios including differential stabilator lock, soft sensor failure, control and stability derivative variations, and air turbulence.

  4. Effect of the ionic strength of pulsed electric field treatment medium on the physicochemical and structural characteristics of lactoferrin.

    Science.gov (United States)

    Sui, Qian; Roginski, Hubert; Williams, Roderick P W; Wooster, Tim J; Versteeg, Cornelis; Wan, Jason

    2010-11-24

    Pulsed electric field (PEF) treatment (35 kV cm(-1) for 19.2 μs using bipolar 2 μs pulses) was conducted on bovine lactoferrin (LF; 0.4 mg mL(-1)) prepared in simulated milk ultrafiltrate (SMUF), at concentrations between 0.2× and 2× normal strength, with electrical conductivities ranging from 0.17 to 1.04 S m(-1). The physicochemical and structural characteristics (LF content by a spectrophotometric and an ELISA method, surface hydrophobicity, electrophoretic mobility, far-UV circular dichroism spectra, and tryptophan fluorescence) of LF dissolved in SMUF of all strengths tested were not changed after PEF treatment. The PEF treatment of LF in 0.2 strength SMUF did not cause the release of LF-bound ferric ion into the aqueous phase, with a concentration of LF-bound iron being the same as that of the untreated LF control (174 μg L(-1)). However, in treatment media with higher ionic strengths, ferric ion was released from the LF molecule into the aqueous phase. The concentration of LF-bound iron decreased from 174 μg L(-1) for the LF treated in 0.2 strength SMUF to 80 μg L(-1) for that treated in double-strength SMUF. The results suggest that the PEF-induced iron depletion of LF does not appear to cause an appreciable conformational change in LF molecules. PEF treatment could be developed as a novel physical way to produce iron-depleted LF, as an alternative to the existing chemical method.

  5. Effect of Temperature on the Structural and Physicochemical Properties of Biochar with Apple Tree Branches as Feedstock Material

    Directory of Open Access Journals (Sweden)

    Shi-Xiang Zhao

    2017-08-01

    Full Text Available The objective of this study was to study the structure and physicochemical properties of biochar derived from apple tree branches (ATBs, whose valorization is crucial for the sustainable development of the apple industry. ATBs were collected from apple orchards located on the Weibei upland of the Loess Plateau and pyrolyzed at 300, 400, 500 and 600 °C (BC300, BC400, BC500 and BC600, respectively. Different analytical techniques were used for the characterization of the different biochars. In particular, proximate and element analyses were performed. Furthermore, the morphological, and textural properties were investigated using scanning electron microscopy (SEM, Fourier-transform infrared (FTIR spectroscopy, Boehm titration and nitrogen manometry. In addition, the thermal stability of biochars was also studied by thermogravimetric analysis. The results indicated that the increasing temperature increased the content of fixed carbon (C, the C content and inorganic minerals (K, P, Fe, Zn, Ca, Mg, while the yield, the content of volatile matter (VM, O and H, cation exchange capacity, and the ratios of O/C and H/C decreased. Comparison between the different samples show that highest pH and ash content were observed in BC500. The number of acidic functional groups decreased as a function of pyrolysis temperature, especially for the carboxylic functional groups. In contrast, a reverse trend was found for the basic functional groups. At a higher temperature, the brunauer–emmett–teller (BET surface area and pore volume are higher mostly due to the increase of the micropore surface area and micropore volume. In addition, the thermal stability of biochars also increased with the increasing temperature. Hence, pyrolysis temperature has a strong effect on biochar properties, and therefore biochars can be produced by changing pyrolysis temperature in order to better meet their applications.

  6. Evaluation of the physicochemical properties of structured materials: metallic, polymeric and ceramic, for the treatment of sour gases

    International Nuclear Information System (INIS)

    Salazar, A.; Chavez, R. H.; Olea, O.; Solis, D.

    2013-01-01

    in this work the physicochemical properties of three structured materials: metallic, polymeric and ceramic, from Sulzer Brothers Limited brand, are studied in order to removal sour gases, by absorption process, in aqueous solution of Monoethanolamine (Mea), at 30% weight. Mechanical properties, chemical composition, morphology and corrosion resistance were determined, using different characterization techniques, such as: 1) mechanically, according to standard procedures Astm E-384-1990, 2) chemically, by the corrosion resistance in the presence of an electrochemical cell, in aqueous solution of H 2 SO 4 , 1 N by Astm G-5-1999, 3) morphologically by scanning electron microscopy technique, and 4) efficiency of separation, by the gas chromatography technique in order to determine the chemical absorption of CO 2 by Mea. The ceramic material was the hardest with 700 Hk value and tensile strength of 90 MPa, likewise showed resistance to corrosion of 10.28 m py, separation efficiency of 74% CO 2 , at 10 minutes. The metallic material had a hardness of 190 Hk and it was the most resistant of tension, with 831 MPa, and corrosion resistance of 780.4 x 10 -6 m py, likewise promoted CO 2 separation efficiency of 90% during the evaluation. The polymeric material presented hardness of 20 Hk and 35 MPa and it was not suffered surface change with electrochemical attack, with 282.4 x 10 -6 m py, and separation efficiency of 88%. Therefore the polymer was the most ductile, with smooth surface and greater resistance with H 2 SO 4 . The metal material was more resistant to plastic deformation and more corrugated surface and the second resistance in the presence of acid medium in aqueous solutions. For all the above, the metallic material is recommended by its greater separation in the reduction of acid gases and the polymer due to its greater chemical resistance. (Author)

  7. Physico-Chemical and Structural Characteristics of Vegetables Cooked Under Sous-Vide, Cook-Vide, and Conventional Boiling.

    Science.gov (United States)

    Iborra-Bernad, C; García-Segovia, P; Martínez-Monzó, J

    2015-08-01

    In this paper, physico-chemical and structural properties of cut and cooked purple-flesh potato, green bean pods, and carrots have been studied. Three different cooking methods have been applied: traditional cooking (boiling water at 100 °C), cook-vide (at 80 and 90 °C) and sous-vide (at 80 °C and 90 °C). Similar firmness was obtained in potato applying the same cooking time using traditional cooking (100 °C), and cook-vide and sous-vide at 90 °C, while in green beans and carrots the application of the sous-vide (90 °C) required longer cooking times than cook-vide (90 °C) and traditional cooking (100 °C). Losses in anthocyanins (for purple-flesh potatoes) and ascorbic acid (for green beans) were higher applying traditional cooking. β-Carotene extraction increased in carrots with traditional cooking and cook-vide (P starch in potatoes cells cooked in contact with water, such as traditional cooking and cook-vide. Traditional cooking was the most aggressive treatment in green beans because the secondary walls were reduced compared with sous-vide and cook-vide. Sous-vide preserved organelles in the carrot cells, which could explain the lower extraction of β-carotene compared with cook-vide and traditional cooking. Sous-vide cooking of purple-flesh potato is recommended to maintain its high anthocyanin content. Traditional boiling could be recommended for carrots because increase β-carotenes availability. For green beans, cook-vide, and sous-vide provided products with higher ascorbic acid content. © 2015 Institute of Food Technologists®

  8. Narcissistic Personality Inventory: structure of the adapted Dutch version.

    Science.gov (United States)

    Barelds, Dick P H; Dijkstra, Pieternel

    2010-04-01

    The present study examined the structure of a Dutch adaptation of the 40-item Narcissistic Personality Inventory (Raskin & Terry, 1988) in a community sample (n = 460) and a student sample (n = 515). Altering the response format of the NPI to a Likert-scale had no apparent effect on the responses. Confirmatory factor analyses supported neither the four-factor structure reported by Emmons (1984), nor the seven-factor structure reported by Raskin and Terry (1988). Instead, exploratory factor analyses supported either a single-factor solution (general narcissism), or a two-factor solution (Authority/Power and Self-Admiration). The validity of the NPI was supported by its relations with sex, age, personality, self-esteem, shame, guilt and social desirability.

  9. Self-Adaptive Stepsize Search Applied to Optimal Structural Design

    Science.gov (United States)

    Nolle, L.; Bland, J. A.

    Structural engineering often involves the design of space frames that are required to resist predefined external forces without exhibiting plastic deformation. The weight of the structure and hence the weight of its constituent members has to be as low as possible for economical reasons without violating any of the load constraints. Design spaces are usually vast and the computational costs for analyzing a single design are usually high. Therefore, not every possible design can be evaluated for real-world problems. In this work, a standard structural design problem, the 25-bar problem, has been solved using self-adaptive stepsize search (SASS), a relatively new search heuristic. This algorithm has only one control parameter and therefore overcomes the drawback of modern search heuristics, i.e. the need to first find a set of optimum control parameter settings for the problem at hand. In this work, SASS outperforms simulated-annealing, genetic algorithms, tabu search and ant colony optimization.

  10. Unsupervised 2D Dimensionality Reduction with Adaptive Structure Learning.

    Science.gov (United States)

    Zhao, Xiaowei; Nie, Feiping; Wang, Sen; Guo, Jun; Xu, Pengfei; Chen, Xiaojiang

    2017-05-01

    In recent years, unsupervised two-dimensional (2D) dimensionality reduction methods for unlabeled large-scale data have made progress. However, performance of these degrades when the learning of similarity matrix is at the beginning of the dimensionality reduction process. A similarity matrix is used to reveal the underlying geometry structure of data in unsupervised dimensionality reduction methods. Because of noise data, it is difficult to learn the optimal similarity matrix. In this letter, we propose a new dimensionality reduction model for 2D image matrices: unsupervised 2D dimensionality reduction with adaptive structure learning (DRASL). Instead of using a predetermined similarity matrix to characterize the underlying geometry structure of the original 2D image space, our proposed approach involves the learning of a similarity matrix in the procedure of dimensionality reduction. To realize a desirable neighbors assignment after dimensionality reduction, we add a constraint to our model such that there are exact [Formula: see text] connected components in the final subspace. To accomplish these goals, we propose a unified objective function to integrate dimensionality reduction, the learning of the similarity matrix, and the adaptive learning of neighbors assignment into it. An iterative optimization algorithm is proposed to solve the objective function. We compare the proposed method with several 2D unsupervised dimensionality methods. K-means is used to evaluate the clustering performance. We conduct extensive experiments on Coil20, AT&T, FERET, USPS, and Yale data sets to verify the effectiveness of our proposed method.

  11. Algorithms and data structures for adaptive multigrid elliptic solvers

    Science.gov (United States)

    Vanrosendale, J.

    1983-01-01

    Adaptive refinement and the complicated data structures required to support it are discussed. These data structures must be carefully tuned, especially in three dimensions where the time and storage requirements of algorithms are crucial. Another major issue is grid generation. The options available seem to be curvilinear fitted grids, constructed on iterative graphics systems, and unfitted Cartesian grids, which can be constructed automatically. On several grounds, including storage requirements, the second option seems preferrable for the well behaved scalar elliptic problems considered here. A variety of techniques for treatment of boundary conditions on such grids are reviewed. A new approach, which may overcome some of the difficulties encountered with previous approaches, is also presented.

  12. Scale-adaptive surface modeling of vascular structures

    Directory of Open Access Journals (Sweden)

    Ma Xin

    2010-11-01

    Full Text Available Abstract Background The effective geometric modeling of vascular structures is crucial for diagnosis, therapy planning and medical education. These applications require good balance with respect to surface smoothness, surface accuracy, triangle quality and surface size. Methods Our method first extracts the vascular boundary voxels from the segmentation result, and utilizes these voxels to build a three-dimensional (3D point cloud whose normal vectors are estimated via covariance analysis. Then a 3D implicit indicator function is computed from the oriented 3D point cloud by solving a Poisson equation. Finally the vessel surface is generated by a proposed adaptive polygonization algorithm for explicit 3D visualization. Results Experiments carried out on several typical vascular structures demonstrate that the presented method yields both a smooth morphologically correct and a topologically preserved two-manifold surface, which is scale-adaptive to the local curvature of the surface. Furthermore, the presented method produces fewer and better-shaped triangles with satisfactory surface quality and accuracy. Conclusions Compared to other state-of-the-art approaches, our method reaches good balance in terms of smoothness, accuracy, triangle quality and surface size. The vessel surfaces produced by our method are suitable for applications such as computational fluid dynamics simulations and real-time virtual interventional surgery.

  13. Phospholipids fatty acids of drinking water reservoir sedimentary microbial community: Structure and function responses to hydrostatic pressure and other physico-chemical properties.

    Science.gov (United States)

    Chai, Bei-Bei; Huang, Ting-Lin; Zhao, Xiao-Guang; Li, Ya-Jiao

    2015-07-01

    Microbial communities in three drinking water reservoirs, with different depth in Xi'an city, were quantified by phospholipids fatty acids analysis and multivariate statistical analysis was employed to interpret their response to different hydrostatic pressure and other physico-chemical properties of sediment and overlying water. Principle component analyses of sediment characteristics parameters showed that hydrostatic pressure was the most important effect factor to differentiate the overlying water quality from three drinking water reservoirs from each other. NH4+ content in overlying water was positive by related to hydrostatic pressure, while DO in water-sediment interface and sediment OC in sediment were negative by related with it. Three drinking water reservoir sediments were characterized by microbial communities dominated by common and facultative anaerobic Gram-positive bacteria, as well as, by sulfur oxidizing bacteria. Hydrostatic pressure and physico-chemical properties of sediments (such as sediment OC, sediment TN and sediment TP) were important effect factors to microbial community structure, especially hydrostatic pressure. It is also suggested that high hydrostatic pressure and low dissolved oxygen concentration stimulated Gram-positive and sulfate-reducing bacteria (SRB) bacterial population in drinking water reservoir sediment. This research supplied a successful application of phospholipids fatty acids and multivariate analysis to investigate microbial community composition response to different environmental factors. Thus, few physico-chemical factors can be used to estimate composition microbial of community as reflected by phospholipids fatty acids, which is difficult to detect.

  14. Distributed adaptive diagnosis of sensor faults using structural response data

    Science.gov (United States)

    Dragos, Kosmas; Smarsly, Kay

    2016-10-01

    The reliability and consistency of wireless structural health monitoring (SHM) systems can be compromised by sensor faults, leading to miscalibrations, corrupted data, or even data loss. Several research approaches towards fault diagnosis, referred to as ‘analytical redundancy’, have been proposed that analyze the correlations between different sensor outputs. In wireless SHM, most analytical redundancy approaches require centralized data storage on a server for data analysis, while other approaches exploit the on-board computing capabilities of wireless sensor nodes, analyzing the raw sensor data directly on board. However, using raw sensor data poses an operational constraint due to the limited power resources of wireless sensor nodes. In this paper, a new distributed autonomous approach towards sensor fault diagnosis based on processed structural response data is presented. The inherent correlations among Fourier amplitudes of acceleration response data, at peaks corresponding to the eigenfrequencies of the structure, are used for diagnosis of abnormal sensor outputs at a given structural condition. Representing an entirely data-driven analytical redundancy approach that does not require any a priori knowledge of the monitored structure or of the SHM system, artificial neural networks (ANN) are embedded into the sensor nodes enabling cooperative fault diagnosis in a fully decentralized manner. The distributed analytical redundancy approach is implemented into a wireless SHM system and validated in laboratory experiments, demonstrating the ability of wireless sensor nodes to self-diagnose sensor faults accurately and efficiently with minimal data traffic. Besides enabling distributed autonomous fault diagnosis, the embedded ANNs are able to adapt to the actual condition of the structure, thus ensuring accurate and efficient fault diagnosis even in case of structural changes.

  15. Staphylococcal Immune Evasion Proteins: Structure, Function, and Host Adaptation.

    Science.gov (United States)

    Koymans, Kirsten J; Vrieling, Manouk; Gorham, Ronald D; van Strijp, Jos A G

    2017-01-01

    Staphylococcus aureus is a successful human and animal pathogen. Its pathogenicity is linked to its ability to secrete a large amount of virulence factors. These secreted proteins interfere with many critical components of the immune system, both innate and adaptive, and hamper proper immune functioning. In recent years, numerous studies have been conducted in order to understand the molecular mechanism underlying the interaction of evasion molecules with the host immune system. Structural studies have fundamentally contributed to our understanding of the mechanisms of action of the individual factors. Furthermore, such studies revealed one of the most striking characteristics of the secreted immune evasion molecules: their conserved structure. Despite high-sequence variability, most immune evasion molecules belong to a small number of structural categories. Another remarkable characteristic is that S. aureus carries most of these virulence factors on mobile genetic elements (MGE) or ex-MGE in its accessory genome. Coevolution of pathogen and host has resulted in immune evasion molecules with a highly host-specific function and prevalence. In this review, we explore how these shared structures and genomic locations relate to function and host specificity. This is discussed in the context of therapeutic options for these immune evasion molecules in infectious as well as in inflammatory diseases.

  16. Design, realization and structural testing of a compliant adaptable wing

    International Nuclear Information System (INIS)

    Molinari, G; Arrieta, A F; Ermanni, P; Quack, M; Morari, M

    2015-01-01

    This paper presents the design, optimization, realization and testing of a novel wing morphing concept, based on distributed compliance structures, and actuated by piezoelectric elements. The adaptive wing features ribs with a selectively compliant inner structure, numerically optimized to achieve aerodynamically efficient shape changes while simultaneously withstanding aeroelastic loads. The static and dynamic aeroelastic behavior of the wing, and the effect of activating the actuators, is assessed by means of coupled 3D aerodynamic and structural simulations. To demonstrate the capabilities of the proposed morphing concept and optimization procedure, the wings of a model airplane are designed and manufactured according to the presented approach. The goal is to replace conventional ailerons, thus to achieve controllability in roll purely by morphing. The mechanical properties of the manufactured components are characterized experimentally, and used to create a refined and correlated finite element model. The overall stiffness, strength, and actuation capabilities are experimentally tested and successfully compared with the numerical prediction. To counteract the nonlinear hysteretic behavior of the piezoelectric actuators, a closed-loop controller is implemented, and its capability of accurately achieving the desired shape adaptation is evaluated experimentally. Using the correlated finite element model, the aeroelastic behavior of the manufactured wing is simulated, showing that the morphing concept can provide sufficient roll authority to allow controllability of the flight. The additional degrees of freedom offered by morphing can be also used to vary the plane lift coefficient, similarly to conventional flaps. The efficiency improvements offered by this technique are evaluated numerically, and compared to the performance of a rigid wing. (paper)

  17. Landscape genetics, adaptive diversity and population structure in Phaseolus vulgaris.

    Science.gov (United States)

    Rodriguez, Monica; Rau, Domenico; Bitocchi, Elena; Bellucci, Elisa; Biagetti, Eleonora; Carboni, Andrea; Gepts, Paul; Nanni, Laura; Papa, Roberto; Attene, Giovanna

    2016-03-01

    Here we studied the organization of genetic variation of the common bean (Phaseolus vulgaris) in its centres of domestication. We used 131 single nucleotide polymorphisms to investigate 417 wild common bean accessions and a representative sample of 160 domesticated genotypes, including Mesoamerican and Andean genotypes, for a total of 577 accessions. By analysing the genetic spatial patterns of the wild common bean, we documented the existence of several genetic groups and the occurrence of variable degrees of diversity in Mesoamerica and the Andes. Moreover, using a landscape genetics approach, we demonstrated that both demographic processes and selection for adaptation were responsible for the observed genetic structure. We showed that the study of correlations between markers and ecological variables at a continental scale can help in identifying local adaptation genes. We also located putative areas of common bean domestication in Mesoamerica, in the Oaxaca Valley, and the Andes, in southern Bolivia-northern Argentina. These observations are of paramount importance for the conservation and exploitation of the genetic diversity preserved within this species and other plant genetic resources. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  18. CONSTRUCTIVE MODEL OF ADAPTATION OF DATA STRUCTURES IN RAM. PART II. CONSTRUCTORS OF SCENARIOS AND ADAPTATION PROCESSES

    Directory of Open Access Journals (Sweden)

    V. I. Shynkarenko

    2016-04-01

    Full Text Available Purpose.The second part of the paper completes presentation of constructive and the productive structures (CPS, modeling adaptation of data structures in memory (RAM. The purpose of the second part in the research is to develop a model of process of adaptation data in a RAM functioning in different hardware and software environments and scenarios of data processing. Methodology. The methodology of mathematical and algorithmic constructionism was applied. In this part of the paper, changes were developed the constructors of scenarios and adaptation processes based on a generalized CPS through its transformational conversions. Constructors are interpreted, specialized CPS. Were highlighted the terminal alphabets of the constructor scenarios in the form of data processing algorithms and the constructor of adaptation – in the form of algorithmic components of the adaptation process. The methodology involves the development of substitution rules that determine the output process of the relevant structures. Findings. In the second part of the paper, system is represented by CPS modeling adaptation data placement in the RAM, namely, constructors of scenarios and of adaptation processes. The result of the implementation of constructor of scenarios is a set of data processing operations in the form of text in the language of programming C#, constructor of the adaptation processes – a process of adaptation, and the result the process of adaptation – the adapted binary code of processing data structures. Originality. For the first time proposed the constructive model of data processing – the scenario that takes into account the order and number of calls to the various elements of data structures and adaptation of data structures to the different hardware and software environments. At the same the placement of data in RAM and processing algorithms are adapted. Constructionism application in modeling allows to link data models and algorithms for

  19. Future-Adapted Urban Structures Utopia, Vision, or Necessity?

    Directory of Open Access Journals (Sweden)

    Wolf Tietze

    2003-05-01

    Full Text Available Behavioural preferences of people are changing rapidly andmaking use of all sons of technical opponunities or progress.These changes mark a general and global process usually summarizedby the term "urbanization" - rightly referring to urbansettlements. Towns and cities are parlicularly prominent manifestationsof cultural achievements of mankind. They are, atthe same time, the most imporlant means of housing, and aretools to create the values for the material base of life. Most citiesand towns do, however, cope no more with the speed of development,they lag behind and end up in structural chaos, theyfail to adapt to the future requirements. As analysis reveals, theforemost reason is inadequate location of functions resulting inunnecessary traffic. Urban settlements are inefficient, indeed,strangling themselves.To help solve this problem a model is presented here of afull-fledged city of average size. Implementation may be accomplishedpiecemeal. It is a realistic target, it is not utopia butnecessity.

  20. On Cognition, Structured Sequence Processing, and Adaptive Dynamical Systems

    Science.gov (United States)

    Petersson, Karl Magnus

    2008-11-01

    Cognitive neuroscience approaches the brain as a cognitive system: a system that functionally is conceptualized in terms of information processing. We outline some aspects of this concept and consider a physical system to be an information processing device when a subclass of its physical states can be viewed as representational/cognitive and transitions between these can be conceptualized as a process operating on these states by implementing operations on the corresponding representational structures. We identify a generic and fundamental problem in cognition: sequentially organized structured processing. Structured sequence processing provides the brain, in an essential sense, with its processing logic. In an approach addressing this problem, we illustrate how to integrate levels of analysis within a framework of adaptive dynamical systems. We note that the dynamical system framework lends itself to a description of asynchronous event-driven devices, which is likely to be important in cognition because the brain appears to be an asynchronous processing system. We use the human language faculty and natural language processing as a concrete example through out.

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

    Science.gov (United States)

    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.

  2. Forecasting of physicochemical properties of rare earth sesquioxides on the base of their electronic structure in condensed state using electronic computer

    International Nuclear Information System (INIS)

    Kutolin, S.A.; Kotyukov, V.I.; Komarova, S.N.; Smirnova, E.G.

    1980-01-01

    A functional dependence between physicochemical properties of rare earth sesquioxides and energy state of rare earth atom sublattice valent electrons in sesquioxides is found out. The results of calculation of a simplified zone strucrure of rare earth sesquioxides are presented. The energy of the band of metal sublattice valent electrons for rare earth oxides is presented by the Chebyshev coefficients and polynomials and is calculated in the atomic units of mass. The density, melting points, standard change of enthalpy entropy, free energy, specific heat, standard entropy, forbidden zone width, static permitivity with a relative error of 10-12%, and thermal value of seeming activation energy, tangent of a dielectric losses angle, puncture voltage in rare earth oxides with a relative error of 20% are calculated on the base of calculation of electronic structure of rare earth sesquioxide in a condensed state and regression equations of calculation of oxide physicochemical properties. It is shown that only the Chebyshev coefficients determining the metal sublattice electronic structure in an oxide are ''information'' ones, i e. they contribute into the quantitative description of the system

  3. Real-time control of geometry and stiffness in adaptive structures

    Science.gov (United States)

    Ramesh, A. V.; Utku, S.; Wada, B. K.

    1991-01-01

    The basic theory is presented for the geometry, stiffness, and damping control of adaptive structures, with emphasis on adaptive truss structures. Necessary and sufficient conditions are given for stress-free geometry control in statically determinate and indeterminate adaptive discrete structures. Two criteria for selecting the controls are proposed, and their use in real-time control is illustrated by numerical simulation results. It is shown that the stiffness and damping control of adaptive truss structures for vibration suppression is possible by elongation and elongation rate dependent feedback forces from the active elements.

  4. Improving predictions of protein-protein interfaces by combining amino acid-specific classifiers based on structural and physicochemical descriptors with their weighted neighbor averages.

    Science.gov (United States)

    de Moraes, Fábio R; Neshich, Izabella A P; Mazoni, Ivan; Yano, Inácio H; Pereira, José G C; Salim, José A; Jardine, José G; Neshich, Goran

    2014-01-01

    Protein-protein interactions are involved in nearly all regulatory processes in the cell and are considered one of the most important issues in molecular biology and pharmaceutical sciences but are still not fully understood. Structural and computational biology contributed greatly to the elucidation of the mechanism of protein interactions. In this paper, we present a collection of the physicochemical and structural characteristics that distinguish interface-forming residues (IFR) from free surface residues (FSR). We formulated a linear discriminative analysis (LDA) classifier to assess whether chosen descriptors from the BlueStar STING database (http://www.cbi.cnptia.embrapa.br/SMS/) are suitable for such a task. Receiver operating characteristic (ROC) analysis indicates that the particular physicochemical and structural descriptors used for building the linear classifier perform much better than a random classifier and in fact, successfully outperform some of the previously published procedures, whose performance indicators were recently compared by other research groups. The results presented here show that the selected set of descriptors can be utilized to predict IFRs, even when homologue proteins are missing (particularly important for orphan proteins where no homologue is available for comparative analysis/indication) or, when certain conformational changes accompany interface formation. The development of amino acid type specific classifiers is shown to increase IFR classification performance. Also, we found that the addition of an amino acid conservation attribute did not improve the classification prediction. This result indicates that the increase in predictive power associated with amino acid conservation is exhausted by adequate use of an extensive list of independent physicochemical and structural parameters that, by themselves, fully describe the nano-environment at protein-protein interfaces. The IFR classifier developed in this study is now

  5. Improving predictions of protein-protein interfaces by combining amino acid-specific classifiers based on structural and physicochemical descriptors with their weighted neighbor averages.

    Directory of Open Access Journals (Sweden)

    Fábio R de Moraes

    Full Text Available Protein-protein interactions are involved in nearly all regulatory processes in the cell and are considered one of the most important issues in molecular biology and pharmaceutical sciences but are still not fully understood. Structural and computational biology contributed greatly to the elucidation of the mechanism of protein interactions. In this paper, we present a collection of the physicochemical and structural characteristics that distinguish interface-forming residues (IFR from free surface residues (FSR. We formulated a linear discriminative analysis (LDA classifier to assess whether chosen descriptors from the BlueStar STING database (http://www.cbi.cnptia.embrapa.br/SMS/ are suitable for such a task. Receiver operating characteristic (ROC analysis indicates that the particular physicochemical and structural descriptors used for building the linear classifier perform much better than a random classifier and in fact, successfully outperform some of the previously published procedures, whose performance indicators were recently compared by other research groups. The results presented here show that the selected set of descriptors can be utilized to predict IFRs, even when homologue proteins are missing (particularly important for orphan proteins where no homologue is available for comparative analysis/indication or, when certain conformational changes accompany interface formation. The development of amino acid type specific classifiers is shown to increase IFR classification performance. Also, we found that the addition of an amino acid conservation attribute did not improve the classification prediction. This result indicates that the increase in predictive power associated with amino acid conservation is exhausted by adequate use of an extensive list of independent physicochemical and structural parameters that, by themselves, fully describe the nano-environment at protein-protein interfaces. The IFR classifier developed in this study

  6. Improving Predictions of Protein-Protein Interfaces by Combining Amino Acid-Specific Classifiers Based on Structural and Physicochemical Descriptors with Their Weighted Neighbor Averages

    Science.gov (United States)

    de Moraes, Fábio R.; Neshich, Izabella A. P.; Mazoni, Ivan; Yano, Inácio H.; Pereira, José G. C.; Salim, José A.; Jardine, José G.; Neshich, Goran

    2014-01-01

    Protein-protein interactions are involved in nearly all regulatory processes in the cell and are considered one of the most important issues in molecular biology and pharmaceutical sciences but are still not fully understood. Structural and computational biology contributed greatly to the elucidation of the mechanism of protein interactions. In this paper, we present a collection of the physicochemical and structural characteristics that distinguish interface-forming residues (IFR) from free surface residues (FSR). We formulated a linear discriminative analysis (LDA) classifier to assess whether chosen descriptors from the BlueStar STING database (http://www.cbi.cnptia.embrapa.br/SMS/) are suitable for such a task. Receiver operating characteristic (ROC) analysis indicates that the particular physicochemical and structural descriptors used for building the linear classifier perform much better than a random classifier and in fact, successfully outperform some of the previously published procedures, whose performance indicators were recently compared by other research groups. The results presented here show that the selected set of descriptors can be utilized to predict IFRs, even when homologue proteins are missing (particularly important for orphan proteins where no homologue is available for comparative analysis/indication) or, when certain conformational changes accompany interface formation. The development of amino acid type specific classifiers is shown to increase IFR classification performance. Also, we found that the addition of an amino acid conservation attribute did not improve the classification prediction. This result indicates that the increase in predictive power associated with amino acid conservation is exhausted by adequate use of an extensive list of independent physicochemical and structural parameters that, by themselves, fully describe the nano-environment at protein-protein interfaces. The IFR classifier developed in this study is now

  7. Brain: a complex adaptive structure at multiple levels

    Science.gov (United States)

    Klein, Bradley G.

    2001-10-01

    The human brain is comprised of over 100 billion neurons organized into tracts, nuclei, circuits and systems. This provides innumerable elegant abilities that rely on the nervous system to act as a complex adaptive structure (CAS). This property is apparent with respect to overall function, the function of individual neurons and the function of sensory and motor systems. At the overall functional level, the nervous system monitors the environments and can alter that environment. Alterations such as turning on a light switch or changing the diameter of neural vasculature, can improve the performance or chance for survival of the nervous system. Individual neurons can alter the activity of their electrogenic pumps, their rate of transmitter synthesis, their neurotransmitter release and their receptor density in order to maintain optimal functioning in a circuit following changes in their micro-environment. At the systems level, the visual system adjusts the orientation of the eyes or pupillary diameter to receive the highest quality visual information. In the motor system, the myotatic reflex maintains muscle position in the face of changing load, and the gain of the muscle organ responsible for the myotatic reflex can also be automatically adjusted. Internal homeostasis, essential for optimal performance of the nervous system, can be achieved through complex behavioral actions such as feeding. The hypothalamus plays an important role in such behaviors and in the type of sensorimotor integration responsible for the CAS nature of overall nervous system function. Thinking about the CAS characteristics of the nervous system may lead to development of non-biological CAS prostheses for the brain.

  8. Morphing wing structure with controllable twist based on adaptive bending-twist coupling

    Science.gov (United States)

    Raither, Wolfram; Heymanns, Matthias; Bergamini, Andrea; Ermanni, Paolo

    2013-06-01

    A novel semi-passive morphing airfoil concept based on variable bending-twist coupling induced by adaptive shear center location and torsional stiffness is presented. Numerical parametric studies and upscaling show that the concept relying on smart materials permits effective twist control while offering the potential of being lightweight and energy efficient. By means of an experimental characterization of an adaptive beam and a scaled adaptive wing structure, effectiveness and producibility of the structural concept are demonstrated.

  9. Morphing wing structure with controllable twist based on adaptive bending–twist coupling

    International Nuclear Information System (INIS)

    Raither, Wolfram; Heymanns, Matthias; Ermanni, Paolo; Bergamini, Andrea

    2013-01-01

    A novel semi-passive morphing airfoil concept based on variable bending–twist coupling induced by adaptive shear center location and torsional stiffness is presented. Numerical parametric studies and upscaling show that the concept relying on smart materials permits effective twist control while offering the potential of being lightweight and energy efficient. By means of an experimental characterization of an adaptive beam and a scaled adaptive wing structure, effectiveness and producibility of the structural concept are demonstrated. (paper)

  10. Adaptation.

    Science.gov (United States)

    Broom, Donald M

    2006-01-01

    The term adaptation is used in biology in three different ways. It may refer to changes which occur at the cell and organ level, or at the individual level, or at the level of gene action and evolutionary processes. Adaptation by cells, especially nerve cells helps in: communication within the body, the distinguishing of stimuli, the avoidance of overload and the conservation of energy. The time course and complexity of these mechanisms varies. Adaptive characters of organisms, including adaptive behaviours, increase fitness so this adaptation is evolutionary. The major part of this paper concerns adaptation by individuals and its relationships to welfare. In complex animals, feed forward control is widely used. Individuals predict problems and adapt by acting before the environmental effect is substantial. Much of adaptation involves brain control and animals have a set of needs, located in the brain and acting largely via motivational mechanisms, to regulate life. Needs may be for resources but are also for actions and stimuli which are part of the mechanism which has evolved to obtain the resources. Hence pigs do not just need food but need to be able to carry out actions like rooting in earth or manipulating materials which are part of foraging behaviour. The welfare of an individual is its state as regards its attempts to cope with its environment. This state includes various adaptive mechanisms including feelings and those which cope with disease. The part of welfare which is concerned with coping with pathology is health. Disease, which implies some significant effect of pathology, always results in poor welfare. Welfare varies over a range from very good, when adaptation is effective and there are feelings of pleasure or contentment, to very poor. A key point concerning the concept of individual adaptation in relation to welfare is that welfare may be good or poor while adaptation is occurring. Some adaptation is very easy and energetically cheap and

  11. Physico-chemical and structural properties of the surfaces of Peptostreptococcus micros and Streptococcus mitis as compared to those of mutans streptococci, Streptococcus sanguis and Streptococcus salivarius.

    Science.gov (United States)

    Cowan, M M; van der Mei, H C; Rouxhet, P G; Busscher, H J

    1992-12-01

    The surface properties of nine Streptococcus mitis and four Peptostreptococcus micros strains from the oral cavity were examined and compared with a large group of oral streptococci. Zeta potential and contact angle measurements were employed to determine physico-chemical cell surface properties. In addition, elemental surface concentration ratios were obtained via X-ray photoelectron spectroscopy, and surface structures were examined with transmission electron microscopy. The S. mitis and P. micros strains were found to have higher isoelectric points, higher hydrophobicities and higher N/C surface concentration ratios than some other oral streptococci. The combined data suggest that both species possess large amounts of surface protein. All the S. mitis strains displayed abundant surface fibrils in negative staining, but the P. micros strains were devoid of surface appendages indicating that surface protein is present in different forms in the two species. The surfaces of S. mitis and P. micros type strains differed significantly from the other strains examined.

  12. Physicochemical and micro-structural properties of flours, starch and proteins from two varieties of legumes: bambara groundnut (Vigna subterranea).

    Science.gov (United States)

    Kaptso, Kuaté Giscard; Njintang, Yanou Nicolas; Nguemtchouin, Mbouga Marie Goletti; Scher, Joël; Hounhouigan, Joseph; Mbofung, Carl Moses

    2015-08-01

    This work is part of a large study aimed to evaluate the potential of bambara groundnut (Vigna subterranea) flour as starting raw material for the preparation of a widely cherished legume-based food product known as koki. Towards this objective, the flours from two varieties of bambara groundnut along with their respective starch and protein isolates were analyzed for some physicochemical and microstructural properties. It was observed that bambara flour contained appreciable amount of proteins (24.0-25.5 g/100 g), carbohydrates (57.9-61.7 g/100 g), fiber (3.45-3.68 g/100 g) and ash (3.65-3.85 g/100 g) with marginal differences between both varieties. The properties of starch and proteins isolated from the flours were different from one variety to another. In particular the starch granules of the white variety were larger (size range 10-35 μm) and polygonal while those from the black variety were smaller (size range 6-15 μm) and spherical in shape. In addition, the peak of gelatinization temperature was higher for white variety (81.7 °C) than for black variety (77.5 °C). The gelatinization temperature and the enthalpy of gelatinization of starch in the flours were systematically lower than for the starch isolates, suggesting an interaction of starch with other components on the gelatinization process.

  13. Adaptation

    International Development Research Centre (IDRC) Digital Library (Canada)

    . Dar es Salaam. Durban. Bloemfontein. Antananarivo. Cape Town. Ifrane ... program strategy. A number of CCAA-supported projects have relevance to other important adaptation-related themes such as disaster preparedness and climate.

  14. Adapt

    Science.gov (United States)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  15. Chemometric analysis of correlations between electronic absorption characteristics and structural and/or physicochemical parameters for ampholytic substances of biological and pharmaceutical relevance

    Science.gov (United States)

    Judycka-Proma, U.; Bober, L.; Gajewicz, A.; Puzyn, T.; Błażejowski, J.

    2015-03-01

    Forty ampholytic compounds of biological and pharmaceutical relevance were subjected to chemometric analysis based on unsupervised and supervised learning algorithms. This enabled relations to be found between empirical spectral characteristics derived from electronic absorption data and structural and physicochemical parameters predicted by quantum chemistry methods or phenomenological relationships based on additivity rules. It was found that the energies of long wavelength absorption bands are correlated through multiparametric linear relationships with parameters reflecting the bulkiness features of the absorbing molecules as well as their nucleophilicity and electrophilicity. These dependences enable the quantitative analysis of spectral features of the compounds, as well as a comparison of their similarities and certain pharmaceutical and biological features. Three QSPR models to predict the energies of long-wavelength absorption in buffers with pH = 2.5 and pH = 7.0, as well as in methanol, were developed and validated in this study. These models can be further used to predict the long-wavelength absorption energies of untested substances (if they are structurally similar to the training compounds).

  16. Synthesis, structural and physico-chemical studies of the monocrystal superconductor oxides Hg Ba2 Can-1 Cun O2n+2+δ

    International Nuclear Information System (INIS)

    Viallet-Guillen, Virginie

    1998-01-01

    The thesis presents the synthesis and the structural and physico-chemical properties of the mercury-based monocrystal superconductor oxides. The results reported in the first chapter refer to the first three members of the mercury cuprate series Hg-1201, Hg-1212 and Hg-1223. In the second chapter detailed results concerning the structure of these compounds are given highlighting the features common to all cuprates and pointing out the peculiarities of mercury phases. The third chapter presents the phase diagrams (δ, T, p(O 2 )) of the compounds HgBa 2 CuO 4+δ and HgBa 2 Ca 2 Cu 3 O 8+δ obtained by thermogravimetry under controlled atmosphere between 150 deg.C and 500 deg.C and thermodynamic equilibrium conditions. In the case of Hg-1201, the critical temperature shows a variation close to a parabolic law, with an optimal Tc of 96 K (δ≅0.10) while in Hg-1223 the Tc increases linearly with the O content up to the optimal Tc of 135 K (δ≅0.19) and decreases only by 2 K in the over-doped regime. Finally, in the fourth chapter different physical properties are reviewed. The obtained monocrystals allowed studying the resistive transitory anisotropy, the torque, the specific heat, the nuclear magnetic resonance and the Raman diffusion

  17. Adaptation

    International Development Research Centre (IDRC) Digital Library (Canada)

    Nairobi, Kenya. 28 Adapting Fishing Policy to Climate Change with the Aid of Scientific and Endogenous Knowledge. Cap Verde, Gambia,. Guinea, Guinea Bissau,. Mauritania and Senegal. Environment and Development in the Third World. (ENDA-TM). Dakar, Senegal. 29 Integrating Indigenous Knowledge in Climate Risk ...

  18. Substitution effect of pentavalent bismuth ions on the electronic structure and physicochemical properties of perovskite-structured Ba(In0.5Ta0.5-xBix)O3 semiconductors

    International Nuclear Information System (INIS)

    Kim, Tae Woo; Hur, Su Gil; Hwang, Seong-Ju; Park, Hyunwoong; Park, Yiseul; Choi, Wonyong; Choy, Jin-Ho

    2007-01-01

    We have investigated the substitution effect of pentavalent bismuth ions on the electronic structure and physicochemical properties of barium indium tantalate. X-ray diffraction, X-ray absorption spectroscopic, and energy dispersive spectroscopic microprobe analyses reveal that, under oxygen atmosphere of 1 atm, pentavalent Bi ions are successfully stabilized in the octahedral site of the perovskite tantalate lattice. According to diffuse reflectance UV-vis spectroscopic analysis, the Bi substitution gives rise to the significant narrowing of band gap of barium indium tantalate even at a low Bi content of ∼5%, underscoring a high efficiency of Bi substitution in the band gap engineering. Such an effective narrowing of the band gap upon the Bi substitution would be attributable to the lowering of conduction band position due to the high electronegativity of Bi V substituent. As a result of band gap engineering, the Ba(In 0.5 Ta 0.5-x Bi x )O 3 compounds with x ≥ 0.03 can generate photocurrents under visible light irradiation (λ > 420 nm). Based on the present experimental findings, it becomes clear that the substitution of highly electronegative p-block element like Bi V ion can provide a very powerful tool for tailoring the electronic structure and physicochemical properties of wide band gap semiconductors

  19. Physicochemical evolution and positive selection of the ...

    Indian Academy of Sciences (India)

    2010-04-08

    Apr 8, 2010 ... It is not clear whether matK evolves under Darwinian selection. In this study, the gymnosperm Taxaceae, Cephalotaxaceae and Pinaceae were used to illustrate the physicochemical evolution, molecular adaptation and evolutionary dynamics of gene divergence in matKs. matK sequences were amplified ...

  20. Structured estimation - Sample size reduction for adaptive pattern classification

    Science.gov (United States)

    Morgera, S.; Cooper, D. B.

    1977-01-01

    The Gaussian two-category classification problem with known category mean value vectors and identical but unknown category covariance matrices is considered. The weight vector depends on the unknown common covariance matrix, so the procedure is to estimate the covariance matrix in order to obtain an estimate of the optimum weight vector. The measure of performance for the adapted classifier is the output signal-to-interference noise ratio (SIR). A simple approximation for the expected SIR is gained by using the general sample covariance matrix estimator; this performance is both signal and true covariance matrix independent. An approximation is also found for the expected SIR obtained by using a Toeplitz form covariance matrix estimator; this performance is found to be dependent on both the signal and the true covariance matrix.

  1. An Adaptive Mesh Algorithm: Mesh Structure and Generation

    Energy Technology Data Exchange (ETDEWEB)

    Scannapieco, Anthony J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-21

    The purpose of Adaptive Mesh Refinement is to minimize spatial errors over the computational space not to minimize the number of computational elements. The additional result of the technique is that it may reduce the number of computational elements needed to retain a given level of spatial accuracy. Adaptive mesh refinement is a computational technique used to dynamically select, over a region of space, a set of computational elements designed to minimize spatial error in the computational model of a physical process. The fundamental idea is to increase the mesh resolution in regions where the physical variables are represented by a broad spectrum of modes in k-space, hence increasing the effective global spectral coverage of those physical variables. In addition, the selection of the spatially distributed elements is done dynamically by cyclically adjusting the mesh to follow the spectral evolution of the system. Over the years three types of AMR schemes have evolved; block, patch and locally refined AMR. In block and patch AMR logical blocks of various grid sizes are overlaid to span the physical space of interest, whereas in locally refined AMR no logical blocks are employed but locally nested mesh levels are used to span the physical space. The distinction between block and patch AMR is that in block AMR the original blocks refine and coarsen entirely in time, whereas in patch AMR the patches change location and zone size with time. The type of AMR described herein is a locally refi ned AMR. In the algorithm described, at any point in physical space only one zone exists at whatever level of mesh that is appropriate for that physical location. The dynamic creation of a locally refi ned computational mesh is made practical by a judicious selection of mesh rules. With these rules the mesh is evolved via a mesh potential designed to concentrate the nest mesh in regions where the physics is modally dense, and coarsen zones in regions where the physics is modally

  2. Effect of various structure directing agents on the physicochemical properties of the silica aerogels prepared at an ambient pressure

    KAUST Repository

    Sarawade, Pradip

    2013-12-01

    We studied the effects of various surfactants on the textural properties (BET surface area, pore size, and pore volume) of the silica aerogels prepared at an ambient pressure. A simple surface modification of silica gel prepared at an ambient pressure through hydrolysis and polycondensation of TEOS as asilica precursor was conducted using various structure directing agents. The treatment was found to induce a significant difference in the porosity of the silica aerogel. Highly porous silica aerogels with bimodal porous structures were prepared by modifying the surface of the silica wet-gel (alcogel) with trimethylchlorosilane (TMCS) in order to preserve its porosity. The samples were analyzed by small-angle X-ray scattering and nitrogen adsorption. In this work, a possible new type of highly porous hydrophobic silica aerogel with a bimodal porous structure is presented. A hydrophilic extremely porous (high surface area and large pore volume) silica aerogel was obtained by heating the as-synthesized hydrophobic silica aerogel at 400°C for 1 h. There was a significant effect of structure directing agent on the textural properties, such as specific surface area, pore size distribution and cumulative pore volume of the silicaaerogels. © 2013 Elsevier B.V. All rights reserved.

  3. Composites prepared from the waterborne polyurethane cationomers-modified graphene. Part I. Synthesis, structure, and physicochemical properties

    Czech Academy of Sciences Publication Activity Database

    Król, P.; Król, B.; Pielichowska, K.; Špírková, Milena

    2015-01-01

    Roč. 293, č. 2 (2015), s. 421-431 ISSN 0303-402X R&D Projects: GA ČR(CZ) GA13-06700S Institutional support: RVO:61389013 Keywords : polyurethane films * surface structure * AFM microscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.890, year: 2015

  4. Structure design of an innovative adaptive variable camber wing

    Directory of Open Access Journals (Sweden)

    Zhao An-Min

    2018-01-01

    Full Text Available In this paper, an innovative double rib sheet structure is proposed, which can replace the traditional rigid hinge joint with the surface contact. On the one hand, the variable camber wing structural design not only can improve the capacity to sustain more load but also will not increase the overall weight of the wing. On the other hand, it is a simple mechanical structure design to achieve the total wing camber change. Then the numerical simulation results show that the maximum stress at the connect of the wing rib is 88.2MPa, and the double ribs sheet engineering design meet the structural strength requirements. In addition, to make a fair comparison, the parameters of variable camber are fully referenced to the Talon Unmanned Aerial Vehicle (UAV. The results reveal that the total variable camber wing can further enhance aircraft flight efficiency by 29.4%. The design of the whole variable camber wing structure proposed in this paper has high engineering value and feasibility.

  5. Complex Adaptive Systems and the Origins of Adaptive Structure: What Experiments Can Tell Us

    Science.gov (United States)

    Cornish, Hannah; Tamariz, Monica; Kirby, Simon

    2009-01-01

    Language is a product of both biological and cultural evolution. Clues to the origins of key structural properties of language can be found in the process of cultural transmission between learners. Recent experiments have shown that iterated learning by human participants in the laboratory transforms an initially unstructured artificial language…

  6. Genetic algorithms for optimal design and control of adaptive structures

    CERN Document Server

    Ribeiro, R; Dias-Rodrigues, J; Vaz, M

    2000-01-01

    Future High Energy Physics experiments require the use of light and stable structures to support their most precise radiation detection elements. These large structures must be light, highly stable, stiff and radiation tolerant in an environment where external vibrations, high radiation levels, material aging, temperature and humidity gradients are not negligible. Unforeseen factors and the unknown result of the coupling of environmental conditions, together with external vibrations, may affect the position stability of the detectors and their support structures compromising their physics performance. Careful optimization of static and dynamic behavior must be an essential part of the engineering design. Genetic Algorithms ( GA) belong to the group of probabilistic algorithms, combining elements of direct and stochastic search. They are more robust than existing directed search methods with the advantage of maintaining a population of potential solutions. There is a class of optimization problems for which Ge...

  7. Double graphene-layer structures for adaptive devices

    Science.gov (United States)

    Mitin, V.; Ryzhii, V.; Otsuji, T.; Ryzhii, M.; Shur, M. S.

    2014-06-01

    Among different carbon materials (diamond, graphite, fullerene, carbon nanotubes), graphene and more complex graphene-based structures attracted a considerable attention. The gapless energy spectrum of graphene implies that graphene can absorb and emit photons with rather low energies corresponding to terahertz (THz) and infrared (IR) ranges of the electromagnetic spectrum. In this presentation, the discussion is focused on the double-graphene-layer (double-GL) structures. In these structures, GLs are separated by a barrier layer (Boron Nitride, Silicon Carbide, and so on). Applying voltage between GLs, one can realize the situation when one GL is filled with electrons while the other is filled with holes. The variation of the applied voltage leads to the variations of the Fermi energies and, hence, to the change of the interband and intraband absorption of electromagnetic radiation and to the variation of the tunneling current. The plasma oscillations in double-GL structures exhibit interesting features. This is mainly because each GL serves as the gate for the other GL. The spectrum of the plasma oscillations in the double-GL structures falls into the terahertz range (THz) of frequencies and can be effectively controlled by the bias voltage. In this paper, we discuss the effects of the excitation of the plasma oscillations by incoming THz radiation and by optical radiation of two lasers with close frequencies as well as negative differential conductivity of the N-type and Z-type. These effects can be used in resonant THz detectors and THz photomixers. The models of devices based on double-GL structures as well as their characteristics are discussed.

  8. Effects of heat-moisture treatment reaction conditions on the physicochemical and structural properties of maize starch: moisture and length of heating.

    Science.gov (United States)

    Sui, Zhongquan; Yao, Tianming; Zhao, Yue; Ye, Xiaoting; Kong, Xiangli; Ai, Lianzhong

    2015-04-15

    Changes in the properties of normal maize starch (NMS) and waxy maize starch (WMS) after heat-moisture treatment (HMT) under various reaction conditions were investigated. NMS and WMS were adjusted to moisture levels of 20%, 25% and 30% and heated at 100 °C for 2, 4, 8 and 16 h. The results showed that moisture content was the most important factor in determining pasting properties for NMS, whereas the heating length was more important for WMS. Swelling power decreased in NMS but increased in WMS, and while the solubility index decreased for both samples, the changes were largely determined by moisture content. The gelatinisation temperatures of both samples increased with increasing moisture content but remained unchanged with increasing heating length. The Fourier transform infrared (FT-IR) absorbance ratio was affected to different extents by the moisture levels but remained constant with increasing the heating length. The X-ray intensities increased but relative crystallinity decreased to a greater extent with increasing moisture content. This study showed that the levels of moisture content and length of heating had significant impacts on the structural and physicochemical properties of normal and waxy maize starches but to different extents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. An object-oriented approach for parallel self adaptive mesh refinement on block structured grids

    Science.gov (United States)

    Lemke, Max; Witsch, Kristian; Quinlan, Daniel

    1993-01-01

    Self-adaptive mesh refinement dynamically matches the computational demands of a solver for partial differential equations to the activity in the application's domain. In this paper we present two C++ class libraries, P++ and AMR++, which significantly simplify the development of sophisticated adaptive mesh refinement codes on (massively) parallel distributed memory architectures. The development is based on our previous research in this area. The C++ class libraries provide abstractions to separate the issues of developing parallel adaptive mesh refinement applications into those of parallelism, abstracted by P++, and adaptive mesh refinement, abstracted by AMR++. P++ is a parallel array class library to permit efficient development of architecture independent codes for structured grid applications, and AMR++ provides support for self-adaptive mesh refinement on block-structured grids of rectangular non-overlapping blocks. Using these libraries, the application programmers' work is greatly simplified to primarily specifying the serial single grid application and obtaining the parallel and self-adaptive mesh refinement code with minimal effort. Initial results for simple singular perturbation problems solved by self-adaptive multilevel techniques (FAC, AFAC), being implemented on the basis of prototypes of the P++/AMR++ environment, are presented. Singular perturbation problems frequently arise in large applications, e.g. in the area of computational fluid dynamics. They usually have solutions with layers which require adaptive mesh refinement and fast basic solvers in order to be resolved efficiently.

  10. Effect of dry heat treatment on the physicochemical properties and structure of proso millet flour and starch.

    Science.gov (United States)

    Sun, Qingjie; Gong, Min; Li, Ying; Xiong, Liu

    2014-09-22

    Proso millet (Panicum miliaceum L.) flour and starch were heated in a dry state at 130°C for 2 or 4 h. The effects of dry heat treatment (DHT) on the pasting, morphological and structural properties of the samples were evaluated. Dry heat treatment had a more significant effect on the pasting viscosity of flour than starch; it increased the pasting viscosity of the flour while it only increased the final viscosity of the starch. After dry heating, the onset of gelatinization and the peak temperatures of the samples increased significantly while the endothermic enthalpy decreased. Scanning electron microscopy showed that the gel structure of the samples became more compact and the particles were plumper when compared with the native ones. Crystallinity of the samples decreased while the X-ray diffraction patterns remained the same after DHT. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Successive Cambia: A Developmental Oddity or an Adaptive Structure?

    Science.gov (United States)

    Robert, Elisabeth M. R.; Schmitz, Nele; Boeren, Ilse; Driessens, Tess; Herremans, Kristof; De Mey, Johan; Van de Casteele, Elke; Beeckman, Hans; Koedam, Nico

    2011-01-01

    Background Secondary growth by successive cambia is a rare phenomenon in woody plant species. Only few plant species, within different phylogenetic clades, have secondary growth by more than one vascular cambium. Often, these successive cambia are organised concentrically. In the mangrove genus Avicennia however, the successive cambia seem to have a more complex organisation. This study aimed (i) at understanding the development of successive cambia by giving a three-dimensional description of the hydraulic architecture of Avicennia and (ii) at unveiling the possible adaptive nature of growth by successive cambia through a study of the ecological distribution of plant species with concentric internal phloem. Results Avicennia had a complex network of non-cylindrical wood patches, the complexity of which increased with more stressful ecological conditions. As internal phloem has been suggested to play a role in water storage and embolism repair, the spatial organisation of Avicennia wood could provide advantages in the ecologically stressful conditions species of this mangrove genus are growing in. Furthermore, we could observe that 84.9% of the woody shrub and tree species with concentric internal phloem occurred in either dry or saline environments strengthening the hypothesis that successive cambia provide the necessary advantages for survival in harsh environmental conditions. Conclusions Successive cambia are an ecologically important characteristic, which seems strongly related with water-limited environments. PMID:21304983

  12. Successive cambia: a developmental oddity or an adaptive structure?

    Directory of Open Access Journals (Sweden)

    Elisabeth M R Robert

    Full Text Available BACKGROUND: Secondary growth by successive cambia is a rare phenomenon in woody plant species. Only few plant species, within different phylogenetic clades, have secondary growth by more than one vascular cambium. Often, these successive cambia are organised concentrically. In the mangrove genus Avicennia however, the successive cambia seem to have a more complex organisation. This study aimed (i at understanding the development of successive cambia by giving a three-dimensional description of the hydraulic architecture of Avicennia and (ii at unveiling the possible adaptive nature of growth by successive cambia through a study of the ecological distribution of plant species with concentric internal phloem. RESULTS: Avicennia had a complex network of non-cylindrical wood patches, the complexity of which increased with more stressful ecological conditions. As internal phloem has been suggested to play a role in water storage and embolism repair, the spatial organisation of Avicennia wood could provide advantages in the ecologically stressful conditions species of this mangrove genus are growing in. Furthermore, we could observe that 84.9% of the woody shrub and tree species with concentric internal phloem occurred in either dry or saline environments strengthening the hypothesis that successive cambia provide the necessary advantages for survival in harsh environmental conditions. CONCLUSIONS: Successive cambia are an ecologically important characteristic, which seems strongly related with water-limited environments.

  13. Adaptive multimodal vibration suppression using fuzzy-based control with limited structural data

    International Nuclear Information System (INIS)

    Makihara, Kanjuro; Kuroishi, Chikako; Fukunaga, Hisao

    2013-01-01

    We propose a novel fuzzy-based method of adaptive multimodal vibration suppression with limited structural data. The adaptive control consists of fuzzy inference and a semi-active switching approach. We demonstrate it to be applicable to multimodal vibration suppression for vibrating structures, where a single piezoelectric actuator suppresses two modal vibrations simultaneously. Our fuzzy-based semi-active control requires only the structural information of natural frequencies for real-time adaptive feedback, whereas common adaptive controls require highly precise structural models or complete equations of motion. We conduct experiments in semi-active vibration suppression using the proposed fuzzy-based control, and compare the suppression performance of our fuzzy-based approach with conventional controls. The experiments indicate that the proposed fuzzy-based control demonstrates good adaptability when experiencing sudden changes in disturbance excitation, and also demonstrates high suppression performance. The fuzzy-based control can adapt to a wide range of disturbance conditions, both within and outside the range of vibration excitations assumed when the controller is designed. (paper)

  14. Materials for Adaptive Structural Acoustic Control. Volume 3

    Science.gov (United States)

    1994-04-11

    increasing the BaSnO3 content, 1) phenomena of the diffuse phase transition have been investigated intensively. At a temperature several tens°C above...categories of crystal structure; 1); solid solutions with a non-polar component (BaTiO3- BaSnO3 ), 2)1 atomic deficiencies by a dopant (Pbl.x 2+Lax3+(Zr,Ti)l-x

  15. Spiders in Motion: Demonstrating Adaptation, Structure-Function Relationships, and Trade-Offs in Invertebrates

    Science.gov (United States)

    Bowlin, Melissa S.; McLeer, Dorothy F.; Danielson-Francois, Anne M.

    2014-01-01

    Evolutionary history and structural considerations constrain all aspects of animal physiology. Constraints on invertebrate locomotion are especially straightforward for students to observe and understand. In this exercise, students use spiders to investigate the concepts of adaptation, structure-function relationships, and trade-offs. Students…

  16. Adaptive Neuro-Fuzzy Inference System Models for Force Prediction of a Mechatronic Flexible Structure

    DEFF Research Database (Denmark)

    Achiche, S.; Shlechtingen, M.; Raison, M.

    2016-01-01

    This paper presents the results obtained from a research work investigating the performance of different Adaptive Neuro-Fuzzy Inference System (ANFIS) models developed to predict excitation forces on a dynamically loaded flexible structure. For this purpose, a flexible structure is equipped with ...

  17. Structural adaptations of proteins to different biological membranes

    Science.gov (United States)

    Pogozheva, Irina D.; Tristram-Nagle, Stephanie; Mosberg, Henry I.; Lomize, Andrei L.

    2013-01-01

    To gain insight into adaptations of proteins to their membranes, intrinsic hydrophobic thicknesses, distributions of different chemical groups and profiles of hydrogen-bonding capacities (α and β) and the dipolarity/polarizability parameter (π*) were calculated for lipid-facing surfaces of 460 integral α-helical, β-barrel and peripheral proteins from eight types of biomembranes. For comparison, polarity profiles were also calculated for ten artificial lipid bilayers that have been previously studied by neutron and X-ray scattering. Estimated hydrophobic thicknesses are 30-31 Å for proteins from endoplasmic reticulum, thylakoid, and various bacterial plasma membranes, but differ for proteins from outer bacterial, inner mitochondrial and eukaryotic plasma membranes (23.9, 28.6 and 33.5 Å, respectively). Protein and lipid polarity parameters abruptly change in the lipid carbonyl zone that matches the calculated hydrophobic boundaries. Maxima of positively charged protein groups correspond to the location of lipid phosphates at 20-22 Å distances from the membrane center. Locations of Tyr atoms coincide with hydrophobic boundaries, while distributions maxima of Trp rings are shifted by 3-4 Å toward the membrane center. Distributions of Trp atoms indicate the presence of two 5-8 Å-wide midpolar regions with intermediate π* values within the hydrocarbon core, whose size and symmetry depend on the lipid composition of membrane leaflets. Midpolar regions are especially asymmetric in outer bacterial membranes and cell membranes of mesophilic but not hyperthermophilic archaebacteria, indicating the larger width of the central nonpolar region in the later case. In artificial lipid bilayers, midpolar regions are observed up to the level of acyl chain double bonds. PMID:23811361

  18. Design and analysis of adaptive honeycomb structure with pneumatic muscle fibers

    Science.gov (United States)

    Yin, Weilong; Tian, Dongkui; Chen, Yijin

    2012-04-01

    The adaptive honeycomb structure actuated by pneumatic muscle fibers is proposed in this paper. The FE model of adaptive honeycomb structure is developed by use of ANSYS software. The elastics modulus of the developed pneumatic muscle fibers is experimentally determined and their output force is tested. The results show that the contraction ratio of the pneumatic muscle fibers with inner diameter of 2mm could reach up to 26.8% and the force could reach to a value of 27N when the applied pressure is 0.4MPa and the contraction ratio is zero. When the adaptive honeycomb has a certain load and an effective output displacement, the applied force must be greater than a certain value. The adaptive honeycomb must be consumed extra energy when the output displacement and force are produced.

  19. Conflicts of interest improve collective computation of adaptive social structures.

    Science.gov (United States)

    Brush, Eleanor R; Krakauer, David C; Flack, Jessica C

    2018-01-01

    In many biological systems, the functional behavior of a group is collectively computed by the system's individual components. An example is the brain's ability to make decisions via the activity of billions of neurons. A long-standing puzzle is how the components' decisions combine to produce beneficial group-level outputs, despite conflicts of interest and imperfect information. We derive a theoretical model of collective computation from mechanistic first principles, using results from previous work on the computation of power structure in a primate model system. Collective computation has two phases: an information accumulation phase, in which (in this study) pairs of individuals gather information about their fighting abilities and make decisions about their dominance relationships, and an information aggregation phase, in which these decisions are combined to produce a collective computation. To model information accumulation, we extend a stochastic decision-making model-the leaky integrator model used to study neural decision-making-to a multiagent game-theoretic framework. We then test alternative algorithms for aggregating information-in this study, decisions about dominance resulting from the stochastic model-and measure the mutual information between the resultant power structure and the "true" fighting abilities. We find that conflicts of interest can improve accuracy to the benefit of all agents. We also find that the computation can be tuned to produce different power structures by changing the cost of waiting for a decision. The successful application of a similar stochastic decision-making model in neural and social contexts suggests general principles of collective computation across substrates and scales.

  20. Structural and physico-chemical analysis of calcium/strontium substituted, near-invert phosphate based glasses for biomedical applications.

    Science.gov (United States)

    Patel, U; Moss, R M; Hossain, K M Z; Kennedy, A R; Barney, E R; Ahmed, I; Hannon, A C

    2017-09-15

    Neutron diffraction, 23 Na and 31 P NMR, and FTIR spectroscopy have been used to investigate the structural effects of substituting CaO with SrO in a 40P 2 O 5 ·(16-x)CaO·20Na 2 O·24MgO·xSrO glass, where x is 0, 4, 8, 12 and 16mol%. The 31 P solid-state NMR results showed similar amounts of Q 1 and Q 2 units for all of the multicomponent glasses investigated, showing that the substitution of Sr for Ca has no effect on the phosphate network. The M-O coordinations (M=Mg, Ca, Sr, Na) were determined for binary alkali and alkaline earth metaphosphates using neutron diffraction and broad asymmetric distributions of bond length were observed, with coordination numbers that were smaller and bond lengths that were shorter than in corresponding crystals. The Mg-O coordination number was determined most reliably as 5.0(2). The neutron diffraction results for the multicomponent glasses are consistent with a structural model in which the coordination of Ca, Sr and Na is the same as in the binary metaphosphate glass, whereas there is a definite shift of Mg-O bonds to longer distance. There is also a small but consistent increase in the Mg-O coordination number and the width of the distribution of Mg-O bond lengths, as Sr substitutes for Ca. Functional properties, including glass transition temperatures, thermal processing windows, dissolution rates and ion release profiles were also investigated. Dissolution studies showed a decrease in dissolution rate with initial addition of 4mol% SrO, but further addition of SrO showed little change. The ion release profiles followed a similar trend to the observed dissolution rates. The limited changes in structure and dissolution rates observed for substitution of Ca with Sr in these fixed 40mol% P 2 O 5 glasses were attributed to their similarities in terms of ionic size and charge. Phosphate based glasses are extremely well suited for the delivery of therapeutic ions in biomedical applications, and in particular strontium plays an

  1. Synthesis, structure and physicochemical properties of zinc and copper complexes based on sulfonamides containing 8-aminoquinoline ligands

    Directory of Open Access Journals (Sweden)

    Luiz Everson da Silva

    2008-01-01

    Full Text Available Sulfonamides obtained by reaction of 8-aminoquinoline with 4-nitrobenzenesulfonylchloride and 2,4,6-triisopropylbenzenesulfonyl chloride were used to synthesize coordination compounds with CuII and ZnII with a ML2 composition. Determination of the crystal structures of the resulting zinc and copper complexes by X-ray diffraction show a distorted tetrahedral environment for the [Cu(qnbsa2], [Cu(qibsa2] and [Zn(qibsa2] complexes in which the sulfonamide group acts as a bidentate ligand through the nitrogen atoms from the sulfonamidate and quinoline groups. The complex [Zn(qnbsa2] crystallizes with a water molecule from the solvent and the Zn is five-coordinated and shows a bipyramidal-trigonal geometry. The electrochemical and electronic spectroscopy properties of the copper complexes are also discussed.

  2. Synthesis, structure and physicochemical properties of zinc and copper complexes based on sulfonamides containing 8-aminoquinoline ligands

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luiz Everson da; Sousa Junior, Paulo Teixeira de [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil). Dept. de Quimica; Joussef, Antonio Carlos; Piovezan, Clovis; Neves, Ademir [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Quimica]. E-mail: ademir@qmc.ufsc.br

    2008-07-01

    Sulfonamides obtained by reaction of 8-aminoquinoline with 4-nitrobenzenesulfonylchloride and 2,4,6-triisopropylbenzenesulfonyl chloride were used to synthesize coordination compounds with Cu{sup II} and Zn{sup II} with a ML{sub 2} composition. Determination of the crystal structures of the resulting zinc and copper complexes by X-ray diffraction show a distorted tetrahedral environment for the [Cu(qnbsa){sub 2}], [Cu(qibsa){sub 2}] and [Zn(qibsa){sub 2}] complexes in which the sulfonamide group acts as a bidentate ligand through the nitrogen atoms from the sulfonamidate and quinoline groups. The complex [Zn(qnbsa){sub 2}] crystallizes with a water molecule from the solvent and the Zn is five-coordinated and shows a bipyramidal-trigonal geometry. The electrochemical and electronic spectroscopy properties of the copper complexes are also discussed. (author)

  3. Data structures supporting multi-region adaptive isogeometric analysis

    Science.gov (United States)

    Perduta, Anna; Putanowicz, Roman

    2018-01-01

    Since the first paper published in 2005 Isogeometric Analysis (IGA) has gained strong interest and found applications in many engineering problems. Despite the advancement of the method, there are still far fewer software implementations comparing to Finite Element Method. The paper presents an approach to the development of data structures that can support multi-region IGA with local mesh refinement (patch-based) and possible application in IGA-FEM models. The purpose of this paper is to share original design concepts, that authors have created while developing an IGA package, which other researchers may find beneficial for their own simulation codes.

  4. The relationship of physico-chemical properties and structure to the differential antiplasmodial activity of the cinchona alkaloids

    Directory of Open Access Journals (Sweden)

    Meyer David J

    2003-09-01

    Full Text Available Abstract Background The 8-amino and 9-hydroxy substituents of antimalarial cinchona alkaloids have the erythro orientation while their inactive 9-epimers are threo. From the X-ray structures a 90° difference in torsion angle between the N1-H1 and C9-O12 bonds in the two series is believed to be important. In order to kill the malaria parasite, alkaloids must cross the erythrocyte and parasite membranes to accumulate in the acid digestive vacuole where they prevent detoxication of haematin produced during haemoglobin breakdown. Methods Ionization constants, octanol/water distribution and haematin interaction are examined for eight alkaloids to explain the influence of small structural differences on activity. Results Erythro isomers have a high distribution ratio of 55:1 from plasma to the erythrocyte membrane, while for the more basic threo epimers this is only 4.5:1. This gives an increased transfer rate of the erythro drugs into the erythrocyte and thence into the parasite vacuole where their favourable conformation allows interaction with haematin, inhibiting its dimerization strongly (90 ± 7% and thereby killing the parasite. The threo compounds not only enter more slowly but are then severely restricted from binding to haematin by the gauche alignment of their N1-H1 and C9-O12 bonds. Confirmatory molecular models allowed measurement of angles and bond lengths and computation of the electronic spectrum of a quinine-haematin complex. Conclusion Differences in the antiplasmodial activity of the erythro and threo cinchona alkaloids may therefore be attributed to the cumulative effects of lipid/aqueous distribution ratio and drug-haematin interaction. Possible insights into the mechanism of chloroquine-resistance are discussed.

  5. Electron microscopic and physico-chemical studies of DNA complexes with synthetic oligopeptides: binding specificity and DNA compact structures.

    Science.gov (United States)

    Vengerov, Y Y; Semenov, T E; Surovaya, A N; Sidorova NYu; Streltsov, S A; Khorlin, A A; Zhuze, A L; Gursky, G V

    1988-10-01

    Binding to DNA of two synthetic peptides, Val-Thr-Thr-Val-Val-NH-NH-Dns and Thr-Val-Thr-Lys-Val-Gly-Thr-Lsy-Val-Gly-Thr-Val-Val-NH-NH-Dns (where Dns is a residue of 5-dimethylaminonaphthalene-1-sulfonic acid), has been studied by circular dichroism, electron microscopy and fluorescence methods. It has been found that these two peptides can self-associate in aqueous solution as follows from the fact that concentration-dependent changes are observed in the UV absorbance and fluorescence spectra. The two peptides can bind to DNA both in self-associated and monomeric forms. The pentapeptide in the beta-associated form binds more strongly to poly(dG).poly(dC) than to poly[d(A-C)].poly[d(G-T)] and poly(dA).poly(dT) whereas the tridecapeptide exhibits an opposite order of preferences binding more strongly to poly[d(A-C)].poly[d(G-T)] and poly(dA).poly(dT) than to poly(dG).poly(dC). Binding is a cooperative process which is accompanied by the DNA compaction at peptide/DNA base pair ratios greater than 1. At the initial stage of the compaction process, the coalescence of DNA segments covered by bound peptide molecules leads to the formation of DNA loops stabilized by the interaction between peptide molecules bound to different DNA segments. Further increase in the peptide/DNA ratio leads to the formation of rod-like structures each consisting of two or more double-stranded DNA segments. The final stage of the compaction process involves folding of fibrillar macromolecular complexes into a globular structure containing only one DNA molecule.

  6. Spacer-dependent structural and physicochemical diversity in copper(II) complexes with salicyloyl hydrazones: a monomer and soluble polymers.

    Science.gov (United States)

    Matoga, Dariusz; Szklarzewicz, Janusz; Gryboś, Ryszard; Kurpiewska, Katarzyna; Nitek, Wojciech

    2011-04-18

    Complexation of copper(II) with a series of heterodonor chelating Schiff bases (LL) of salicylic acid hydrazide and aliphatic or cycloaliphatic ketones affords soluble one-dimensional (1D) metallopolymers containing Schiff bases as bridging ligands. Single-crystal X-ray diffraction results reveal nanometer-sized metallopolymeric wires [Cu(μ-LL)(2)](n) with off-axis linkers and a zigzag geometry. Octahedrally coordinated copper centers, exhibiting a Jahn-Teller distortion, are doubly bridged by two Schiff-base molecules in the μ(2)-η(1),η(2) coordination mode. The use of dibutylketone with long alkyl chains as a component for Schiff base formation leads to a distorted square planar monomeric copper(II) complex [Cu(LL)(2)], as evidenced by its X-ray crystal structure. The compounds are characterized by elemental analyses and IR and UV-vis spectroscopy, as well as magnetic susceptibility and cyclic voltammetry measurements. Electrochemical studies on the complexes reveal an existence of polymeric and monomeric forms in solution and the dependence of Cu(II)/Cu(I) reduction potentials on alkyl groups of salicyloyl hydrazone ligands. Polymeric complexes form conducting films on Pt electrodes upon multicycle potential sweeps.

  7. Synthesis, crystal structure, physicochemical properties of hydrogen bonded supramolecular assembly of N,N-diethylanilinium-3, 5-dinitrosalicylate crystal

    Science.gov (United States)

    Rajkumar, M.; Chandramohan, A.

    2017-12-01

    An organic salt, N,N-diethylanilinium 3,5-dinitrosalicylate was synthesized and single crystals grown by employing the slow solvent evaporation solution growth technique in methanol-acetone (1:1) mixture. The electronic transitions of the salt crystal were studied by UV-Visible spectrum. The optical transmittance window and lower wavelength cut-off of grown crystal have been identified by UV-Vis-NIR studies. The FT-IR spectrum was recorded to confirm the presence of various functional groups in the grown crystal. 1H and 13C NMR spectrum were recorded to establish the molecular structure of the title crystal. Single crystal X-ray diffraction data indicated that the crystal belongs to monoclinic crystal system with P21/n space group. The thermal stability of the crystal was established by TG/DTA studies. The mechanical properties of the grown crystal were studied by Vickers' microhardness technique. The dielectric studies indicated that the dielectric constant and dielectric loss decrease exponentially with frequency at different temperatures.

  8. Al and PEG effect on structural and physicochemical properties of CoFe{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Mostaghni, Fatemeh; Abed, Yasaman, E-mail: mostaghnif@yahoo.com [Payam Noor University (Iran, Islamic Republic of)

    2017-05-15

    In this work, pure and Alumina doped cobalt ferrite nanoparticles CoFe{sub 2-x}Al{sub x}O{sub 4} (for x = 0.44) have been synthesized by the sol gel method. The influence of alumina doping on the morphological and mechanical properties of CoFe{sub 2}O{sub 4} nano-particles were investigated by means of X-ray powder diffraction (XRD) and Rietveld analysis. XRD analysis confirmed that the single phase formation of pure nano particles with the expected cubic inverse spinel structure with Fd3m space group and without any impurity phase. Alumina doping were led to a decrease in the crystallite size, lattice parameter, elastic constants and magnitude of moduli. It is explained on the basis of the replacement of Fe ions with half-filled d-shell (3d{sup 5}) and larger radius by Al{sup 3+} ions with a completely filled shell (2p{sup 6}) and smaller radius. (author)

  9. Cobalt(III) complexes as potential anticancer agents: Physicochemical, structural, cytotoxic activity and DNA/protein interactions.

    Science.gov (United States)

    Thamilarasan, V; Sengottuvelan, N; Sudha, A; Srinivasan, P; Chakkaravarthi, G

    2016-09-01

    Cobalt(III) complexes (1-3) such as [Co(acac)(bpy)(N3)2·H2O] 1, [Co(acac)(en)(N3)2] 2, and [Co(acac)(2-pic)(N3)2] 3 (where, acac=acetylacetone, bpy=2.2'-bipyridine, en=ethylenediamine, 2-pic=2-picolylamine and NaN3=sodium azide) were synthesized and characterized. The structure of complexes (1-3) has been determined by single crystal X-ray diffraction studies and the configuration around cobalt(III) ion was distorted octahedral coordination geometry. Density functional theory calculations were performed to examine the molecular geometry and frontier molecular orbital properties of complexes (1-3). DNA binding properties of the cobalt(III) complexes with calf thymus DNA (CT-DNA) were investigated by UV-visible absorption, fluorescence, circular dichroism spectroscopy and viscosity measurements. The docking studies showed the preferred orientation of sterically acceptable Co(III) complexes (1, 2) inside the DNA through the mode of intercalation, whereas complex 3 exhibited minor groove binding modes. The intrinsic binding constants Kb of complexes (1-3) with CT-DNA were in the following order 1>3>2. Complexes (1-3) exhibit a good binding propensity to bovine serum albumin (BSA) and gel electrophoresis assay demonstrated that the complexes (1-3) promote the cleavage of the pBR322 DNA in the presence of 3-mercaptopropionic acid (MPA) and cleavage process was found to proceed by singlet oxygen cleavage mechanism. Further, the in vitro cytotoxicity studies of complexes (1-3) were tested on human breast cancer cell line (MCF-7). Copyright © 2016. Published by Elsevier B.V.

  10. Physico-chemical analysis of tannery solid waste and structural characterization of its isolated humic acids after composting.

    Science.gov (United States)

    Amir, Soumia; Benlboukht, Fatima; Cancian, Nadia; Winterton, Peter; Hafidi, Mohamed

    2008-12-30

    In Marrakech, solid by-products from tanneries are highly polluting, generating large amounts of nitrogenous and organic matter. In the present study composting is tested as a cost-effective method for waste management to overcome many of the environmental hazards and produce a stable, rich material for soil fertilization. Two composting trials were conducted after neutralization by ammonia or lime. The aim of the neutralization was to avoid the antimicrobial effects of the acidity in the tannery waste, thus ensuring correct composting. Different techniques such as elemental analysis and 13C NMR spectroscopy were applied to analyse humic acids isolated from raw and composted materials, and to monitor the process of tannery waste composting, and the stability and maturity of the final product according to the means of neutralization. Comparison of data showed similar behaviour in both trials, but the composting process appeared to be more complete following neutralization with lime. The C, H and N content decreased, while the O increased. The FTIR and 13C NMR spectra show the decrease of aliphatic compounds demonstrated by the reduction of absorbance around 2922cm(-1) and of the resonance in the C-alkyl area around 0-55ppm. The humic acids newly formed during composting were richer in the O-N alkyl and oxidized aromatic structures that increased almost twofold on composting after neutralization with lime. The first principal component axis PC1 (54%) separated C-aliphatic, C-carboxylic and other less stable and less polycondensed compounds such as polyphenols from the more polycondensed O-N alkyl and oxidized C-aromatic compounds.

  11. Biosurfactant-producing bacterium, Pseudomonas aeruginosa MA01 isolated from spoiled apples: physicochemical and structural characteristics of isolated biosurfactant.

    Science.gov (United States)

    Abbasi, Habib; Hamedi, Mir Manochehr; Lotfabad, Tayebe Bagheri; Zahiri, Hossein Shahbani; Sharafi, Hakimeh; Masoomi, Fatemeh; Moosavi-Movahedi, Ali Akbar; Ortiz, Antonio; Amanlou, Massoud; Noghabi, Kambiz Akbari

    2012-02-01

    An extensive investigation was conducted to isolate indigenous bacterial strains with outstanding performance for biosurfactant production from different types of spoiled fruits, food-related products and food processing industries. An isolate was selected from 800 by the highest biosurfactant yield in soybean oil medium and it was identified by 16S rRNA and the two most relevant hypervariable regions of this gene; V3 and V6 as Pseudomonas aeruginosa MA01. The isolate was able to produce 12 g/l of a glycolipid-type biosurfactant and generally less efficient to emulsify vegetable oils compared to hydrocarbons and could emulsify corn and coconut oils more than 50%. However, emulsification index (E(24)) of different hydrocarbons including hexane, toluene, xylene, brake oil, kerosene and hexadecane was between 55.8% and 100%. The surface tension of pure water decreased gradually with increasing biosurfactant concentration to 32.5 mNm(-1) with critical micelle concentration (CMC) value of 10.1mg/l. Among all carbon substrates examined, vegetable oils were the most effective on biosurfactant production. Two glycolipid fractions were purified from the biosurfactant crude extracts, and FTIR and ES-MS were used to determine the structure of these compounds. The analysis indicated the presence of three major monorhamnolipid species: R(1)C(10)C(10), R(1)C(10)C(12:1), and R(1)C(10)C(12); as well as another three major dirhamnolipid species: R(2)C(10)C(10), R(2)C(10)C(12:1), and R(2)C(10)C(12). The strain sweep experiment for measuring the linear viscoelastic of biosurfactant showed that typical behavior characteristics of a weak viscoelastic gel, with storage modulus greater than loss modulus at all frequencies examined, both showing some frequency dependence. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  12. Conforming to interface structured adaptive mesh refinement: 3D algorithm and implementation

    Science.gov (United States)

    Nagarajan, Anand; Soghrati, Soheil

    2018-03-01

    A new non-iterative mesh generation algorithm named conforming to interface structured adaptive mesh refinement (CISAMR) is introduced for creating 3D finite element models of problems with complex geometries. CISAMR transforms a structured mesh composed of tetrahedral elements into a conforming mesh with low element aspect ratios. The construction of the mesh begins with the structured adaptive mesh refinement of elements in the vicinity of material interfaces. An r-adaptivity algorithm is then employed to relocate selected nodes of nonconforming elements, followed by face-swapping a small fraction of them to eliminate tetrahedrons with high aspect ratios. The final conforming mesh is constructed by sub-tetrahedralizing remaining nonconforming elements, as well as tetrahedrons with hanging nodes. In addition to studying the convergence and analyzing element-wise errors in meshes generated using CISAMR, several example problems are presented to show the ability of this method for modeling 3D problems with intricate morphologies.

  13. A New Type of In-Pipe Inspection Minirobot with Adaptable Structure (IPMR-3

    Directory of Open Access Journals (Sweden)

    Andrei Pop

    2016-06-01

    Full Text Available Pipe damages and imperfections led to a start in researching ways of inspecting and maintaining the pipelines. An attractive solution is using mobile robots for this matter. This paper presents the development process of a wheeled in-pipe minirobot with adaptable structure called IPMR-3. IPMR-3has three articulated mechanisms placed at 120° angles around its central axis. The actuation is done with three DC motors. IPMR-3 can adapt its structure to pipe diameters ranged between 220 and 380 mm. The end of the paper presents the image capturing method, achieved with a C910 wireless video camera, and images from the testing process.

  14. Structural and Psycho-Social Limits to Climate Change Adaptation in the Great Barrier Reef Region.

    Directory of Open Access Journals (Sweden)

    Louisa S Evans

    Full Text Available Adaptation, as a strategy to respond to climate change, has limits: there are conditions under which adaptation strategies fail to alleviate impacts from climate change. Research has primarily focused on identifying absolute bio-physical limits. This paper contributes empirical insight to an emerging literature on the social limits to adaptation. Such limits arise from the ways in which societies perceive, experience and respond to climate change. Using qualitative data from multi-stakeholder workshops and key-informant interviews with representatives of the fisheries and tourism sectors of the Great Barrier Reef region, we identify psycho-social and structural limits associated with key adaptation strategies, and examine how these are perceived as more or less absolute across levels of organisation. We find that actors experience social limits to adaptation when: i the effort of pursuing a strategy exceeds the benefits of desired adaptation outcomes; ii the particular strategy does not address the actual source of vulnerability, and; iii the benefits derived from adaptation are undermined by external factors. We also find that social limits are not necessarily more absolute at higher levels of organisation: respondents perceived considerable opportunities to address some psycho-social limits at the national-international interface, while they considered some social limits at the local and regional levels to be effectively absolute.

  15. Structural and Psycho-Social Limits to Climate Change Adaptation in the Great Barrier Reef Region.

    Science.gov (United States)

    Evans, Louisa S; Hicks, Christina C; Adger, W Neil; Barnett, Jon; Perry, Allison L; Fidelman, Pedro; Tobin, Renae

    2016-01-01

    Adaptation, as a strategy to respond to climate change, has limits: there are conditions under which adaptation strategies fail to alleviate impacts from climate change. Research has primarily focused on identifying absolute bio-physical limits. This paper contributes empirical insight to an emerging literature on the social limits to adaptation. Such limits arise from the ways in which societies perceive, experience and respond to climate change. Using qualitative data from multi-stakeholder workshops and key-informant interviews with representatives of the fisheries and tourism sectors of the Great Barrier Reef region, we identify psycho-social and structural limits associated with key adaptation strategies, and examine how these are perceived as more or less absolute across levels of organisation. We find that actors experience social limits to adaptation when: i) the effort of pursuing a strategy exceeds the benefits of desired adaptation outcomes; ii) the particular strategy does not address the actual source of vulnerability, and; iii) the benefits derived from adaptation are undermined by external factors. We also find that social limits are not necessarily more absolute at higher levels of organisation: respondents perceived considerable opportunities to address some psycho-social limits at the national-international interface, while they considered some social limits at the local and regional levels to be effectively absolute.

  16. Structural and Psycho-Social Limits to Climate Change Adaptation in the Great Barrier Reef Region

    Science.gov (United States)

    Evans, Louisa S.; Hicks, Christina C.; Adger, W. Neil; Barnett, Jon; Perry, Allison L.; Fidelman, Pedro; Tobin, Renae

    2016-01-01

    Adaptation, as a strategy to respond to climate change, has limits: there are conditions under which adaptation strategies fail to alleviate impacts from climate change. Research has primarily focused on identifying absolute bio-physical limits. This paper contributes empirical insight to an emerging literature on the social limits to adaptation. Such limits arise from the ways in which societies perceive, experience and respond to climate change. Using qualitative data from multi-stakeholder workshops and key-informant interviews with representatives of the fisheries and tourism sectors of the Great Barrier Reef region, we identify psycho-social and structural limits associated with key adaptation strategies, and examine how these are perceived as more or less absolute across levels of organisation. We find that actors experience social limits to adaptation when: i) the effort of pursuing a strategy exceeds the benefits of desired adaptation outcomes; ii) the particular strategy does not address the actual source of vulnerability, and; iii) the benefits derived from adaptation are undermined by external factors. We also find that social limits are not necessarily more absolute at higher levels of organisation: respondents perceived considerable opportunities to address some psycho-social limits at the national-international interface, while they considered some social limits at the local and regional levels to be effectively absolute. PMID:26960200

  17. An Improved Variable Structure Adaptive Filter Design and Analysis for Acoustic Echo Cancellation

    Directory of Open Access Journals (Sweden)

    A. Kar

    2015-04-01

    Full Text Available In this research an advance variable structure adaptive Multiple Sub-Filters (MSF based algorithm for single channel Acoustic Echo Cancellation (AEC is proposed and analyzed. This work suggests a new and improved direction to find the optimum tap-length of adaptive filter employed for AEC. The structure adaptation, supported by a tap-length based weight update approach helps the designed echo canceller to maintain a trade-off between the Mean Square Error (MSE and time taken to attain the steady state MSE. The work done in this paper focuses on replacing the fixed length sub-filters in existing MSF based AEC algorithms which brings refinements in terms of convergence, steady state error and tracking over the single long filter, different error and common error algorithms. A dynamic structure selective coefficient update approach to reduce the structural and computational cost of adaptive design is discussed in context with the proposed algorithm. Simulated results reveal a comparative performance analysis over proposed variable structure multiple sub-filters designs and existing fixed tap-length sub-filters based acoustic echo cancellers.

  18. Modified Adaptive Control for Region 3 Operation in the Presence of Wind Turbine Structural Modes

    Science.gov (United States)

    Frost, Susan Alane; Balas, Mark J.; Wright, Alan D.

    2010-01-01

    Many challenges exist for the operation of wind turbines in an efficient manner that is reliable and avoids component fatigue and failure. Turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, possibly causing component fatigue and failure. Wind turbine manufacturers are highly motivated to reduce component fatigue and failure that can lead to loss of revenue due to turbine down time and maintenance costs. The trend in wind turbine design is toward larger, more flexible turbines that are ideally suited to adaptive control methods due to the complexity and expense required to create accurate models of their dynamic characteristics. In this paper, we design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed horizontal axis wind turbine operating in Region 3. The objective of the adaptive pitch controller is to regulate generator speed, accommodate wind gusts, and reduce the excitation of structural modes in the wind turbine. The control objective is accomplished by collectively pitching the turbine blades. The adaptive collective pitch controller for Region 3 was compared in simulations with a baseline classical Proportional Integrator (PI) collective pitch controller. The adaptive controller will demonstrate the ability to regulate generator speed in Region 3, while accommodating gusts, and reducing the excitation of certain structural modes in the wind turbine.

  19. Structural, physicochemical characterization and antimicrobial ...

    Indian Academy of Sciences (India)

    Badiaa Essghaier1 Jawher Abdelhak2 Amani Naouar1 Nourchene Toukebri1 Mohamed Faouzi Zid2 Najla Sadfi-Zouaoui1. Laboratoire Microorganismes et Biomolécules Actives, Faculté des Sciences, 2092 El Manar, Tunis, Tunisie; Laboratoire de Matériaux et Cristallochimie, Département de chimie, Faculté des Sciences ...

  20. Structural, physicochemical characterization and antimicrobial ...

    Indian Academy of Sciences (India)

    17. Nakamoto K 2009 In Infrared and Raman Spectra of. Inorganic and Coordination Compounds Part B: Appli- cations in Coordination, Organometallic, and Bioinor- ganic Chemistry 6th ed. (Hoboken, New Jersey: John. Wiley). 18. Lever A B P 1984 In Inorganic Electronic Spectroscopy. 2nded. (Amsterdam: Elsevier) p. 212.

  1. Adaptive Functional-Based Neuro-Fuzzy-PID Incremental Controller Structure

    Directory of Open Access Journals (Sweden)

    Ashraf Ahmed Fahmy

    2014-03-01

    Full Text Available This paper presents an adaptive functional-based Neuro-fuzzy-PID incremental (NFPID controller structure that can be tuned either offline or online according to required controller performance. First, differential membership functions are used to represent the fuzzy membership functions of the input-output space of the three term controller. Second, controller rules are generated based on the discrete proportional, derivative, and integral function for the fuzzy space. Finally, a fully differentiable fuzzy neural network is constructed to represent the developed controller for either offline or online controller parameter adaptation.  Two different adaptation methods are used for controller tuning, offline method based on controller transient performance cost function optimization using Bees Algorithm, and online method based on tracking error minimization using back-propagation with momentum algorithm. The proposed control system was tested to show the validity of the controller structure over a fixed PID controller gains to control SCARA type robot arm.

  2. Adaptive Crack Modeling with Interface Solid Elements for Plain and Fiber Reinforced Concrete Structures.

    Science.gov (United States)

    Zhan, Yijian; Meschke, Günther

    2017-07-08

    The effective analysis of the nonlinear behavior of cement-based engineering structures not only demands physically-reliable models, but also computationally-efficient algorithms. Based on a continuum interface element formulation that is suitable to capture complex cracking phenomena in concrete materials and structures, an adaptive mesh processing technique is proposed for computational simulations of plain and fiber-reinforced concrete structures to progressively disintegrate the initial finite element mesh and to add degenerated solid elements into the interfacial gaps. In comparison with the implementation where the entire mesh is processed prior to the computation, the proposed adaptive cracking model allows simulating the failure behavior of plain and fiber-reinforced concrete structures with remarkably reduced computational expense.

  3. Methodology for Simulation and Analysis of Complex Adaptive Supply Network Structure and Dynamics Using Information Theory

    Directory of Open Access Journals (Sweden)

    Joshua Rodewald

    2016-10-01

    Full Text Available Supply networks existing today in many industries can behave as complex adaptive systems making them more difficult to analyze and assess. Being able to fully understand both the complex static and dynamic structures of a complex adaptive supply network (CASN are key to being able to make more informed management decisions and prioritize resources and production throughout the network. Previous efforts to model and analyze CASN have been impeded by the complex, dynamic nature of the systems. However, drawing from other complex adaptive systems sciences, information theory provides a model-free methodology removing many of those barriers, especially concerning complex network structure and dynamics. With minimal information about the network nodes, transfer entropy can be used to reverse engineer the network structure while local transfer entropy can be used to analyze the network structure’s dynamics. Both simulated and real-world networks were analyzed using this methodology. Applying the methodology to CASNs allows the practitioner to capitalize on observations from the highly multidisciplinary field of information theory which provides insights into CASN’s self-organization, emergence, stability/instability, and distributed computation. This not only provides managers with a more thorough understanding of a system’s structure and dynamics for management purposes, but also opens up research opportunities into eventual strategies to monitor and manage emergence and adaption within the environment.

  4. Evaluating an Objective Structured Clinical Examination (OSCE) Adapted for Social Work

    Science.gov (United States)

    Bogo, Marion; Regehr, Cheryl; Katz, Ellen; Logie, Carmen; Tufford, Lea; Litvack, Andrea

    2012-01-01

    Objectives: To evaluate an objective structured clinical examination (OSCE) adapted for social work in a lab course and examine the degree to which it predicts competence in the practicum. Method: 125 Masters students participated in a one-scenario OSCE and wrote responses to standardized reflection questions. OSCE performance and reflections were…

  5. Adapting Objective Structured Clinical Examinations to Assess Social Work Students' Performance and Reflections

    Science.gov (United States)

    Bogo, Marion; Regehr, Cheryl; Logie, Carmen; Katz, Ellen; Mylopoulos, Maria; Regehr, Glenn

    2011-01-01

    The development of standardized, valid, and reliable methods for assessment of students' practice competence continues to be a challenge for social work educators. In this study, the Objective Structured Clinical Examination (OSCE), originally used in medicine to assess performance through simulated interviews, was adapted for social work to…

  6. Book review: Decision making in natural resource management: A structured adaptive approach

    Science.gov (United States)

    Fuller, Angela K.

    2014-01-01

    No abstract available.Book information: Decision Making in Natural Resource Management: A Structured Adaptive Approach. Michael J. Conroy and James T. Peterson, 2013. Wiley-Blackwell, Oxford, UK. 456 pp. $99.95 paperback. ISBN: 978-0-470-67174-0.

  7. Parallel structures for disaster risk reduction and climate change adaptation in Southern Africa

    Directory of Open Access Journals (Sweden)

    Per Becker

    2013-01-01

    Full Text Available During the last decade, the interest of the international community in the concepts of disaster risk reduction and climate change adaptation has been growing immensely. Even though an increasing number of scholars seem to view these concepts as two sides of the same coin (at least when not considering the potentially positive effects of climate change, in practice the two concepts have developed in parallel rather than in an integrated manner when it comes to policy, rhetoric and funding opportunities amongst international organisations and donors. This study investigates the extent of the creation of parallel structures for disaster risk reduction and climate change adaptation in the Southern African Development Community (SADC region. The chosen methodology for the study is a comparative case study and the data are collected through focus groups and content analysis of documentary sources, as well as interviews with key informants. The results indicate that parallel structures for disaster risk reduction and climate change adaptation have been established in all but one of the studied countries. The qualitative interviews performed in some of the countries indicate that stakeholders in disaster risk reduction view this duplication of structures as unfortunate, inefficient and a fertile setup for conflict over resources for the implementation of similar activities. Additional research is called for in order to study the concrete effects of having these parallel structures as a foundation for advocacy for more efficient future disaster risk reduction and climate change adaptation.

  8. Structure identification and adaptive synchronization of uncertain general complex dynamical networks

    International Nuclear Information System (INIS)

    Xu Yuhua; Zhou Wuneng; Fang Jian'an; Lu Hongqian

    2009-01-01

    This Letter proposes an approach to identify the topological structure and unknown parameters for uncertain general complex networks simultaneously. By designing effective adaptive controllers, we achieve synchronization between two complex networks. The unknown network topological structure and system parameters of uncertain general complex dynamical networks are identified simultaneously in the process of synchronization. Several useful criteria for synchronization are given. Finally, an illustrative example is presented to demonstrate the application of the theoretical results.

  9. Structure identification and adaptive synchronization of uncertain general complex dynamical networks

    Energy Technology Data Exchange (ETDEWEB)

    Xu Yuhua, E-mail: yuhuaxu2004@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China) and Department of Maths, Yunyang Teacher' s College, Hubei 442000 (China); Zhou Wuneng, E-mail: wnzhou@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Fang Jian' an [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Lu Hongqian [Shandong Institute of Light Industry, Shandong Jinan 250353 (China)

    2009-12-28

    This Letter proposes an approach to identify the topological structure and unknown parameters for uncertain general complex networks simultaneously. By designing effective adaptive controllers, we achieve synchronization between two complex networks. The unknown network topological structure and system parameters of uncertain general complex dynamical networks are identified simultaneously in the process of synchronization. Several useful criteria for synchronization are given. Finally, an illustrative example is presented to demonstrate the application of the theoretical results.

  10. A new adaptive mesh refinement data structure with an application to detonation

    Science.gov (United States)

    Ji, Hua; Lien, Fue-Sang; Yee, Eugene

    2010-11-01

    A new Cell-based Structured Adaptive Mesh Refinement (CSAMR) data structure is developed. In our CSAMR data structure, Cartesian-like indices are used to identify each cell. With these stored indices, the information on the parent, children and neighbors of a given cell can be accessed simply and efficiently. Owing to the usage of these indices, the computer memory required for storage of the proposed AMR data structure is only {5}/{8} word per cell, in contrast to the conventional oct-tree [P. MacNeice, K.M. Olson, C. Mobary, R. deFainchtein, C. Packer, PARAMESH: a parallel adaptive mesh refinement community toolkit, Comput. Phys. Commun. 330 (2000) 126] and the fully threaded tree (FTT) [A.M. Khokhlov, Fully threaded tree algorithms for adaptive mesh fluid dynamics simulations, J. Comput. Phys. 143 (1998) 519] data structures which require, respectively, 19 and 2{3}/{8} words per cell for storage of the connectivity information. Because the connectivity information (e.g., parent, children and neighbors) of a cell in our proposed AMR data structure can be accessed using only the cell indices, a tree structure which was required in previous approaches for the organization of the AMR data is no longer needed for this new data structure. Instead, a much simpler hash table structure is used to maintain the AMR data, with the entry keys in the hash table obtained directly from the explicitly stored cell indices. The proposed AMR data structure simplifies the implementation and parallelization of an AMR code. Two three-dimensional test cases are used to illustrate and evaluate the computational performance of the new CSAMR data structure.

  11. Block-structured adaptive meshes and reduced grids for atmospheric general circulation models.

    Science.gov (United States)

    Jablonowski, Christiane; Oehmke, Robert C; Stout, Quentin F

    2009-11-28

    Adaptive mesh refinement techniques offer a flexible framework for future variable-resolution climate and weather models since they can focus their computational mesh on certain geographical areas or atmospheric events. Adaptive meshes can also be used to coarsen a latitude-longitude grid in polar regions. This allows for the so-called reduced grid setups. A spherical, block-structured adaptive grid technique is applied to the Lin-Rood finite-volume dynamical core for weather and climate research. This hydrostatic dynamics package is based on a conservative and monotonic finite-volume discretization in flux form with vertically floating Lagrangian layers. The adaptive dynamical core is built upon a flexible latitude-longitude computational grid and tested in two- and three-dimensional model configurations. The discussion is focused on static mesh adaptations and reduced grids. The two-dimensional shallow water setup serves as an ideal testbed and allows the use of shallow water test cases like the advection of a cosine bell, moving vortices, a steady-state flow, the Rossby-Haurwitz wave or cross-polar flows. It is shown that reduced grid configurations are viable candidates for pure advection applications but should be used moderately in nonlinear simulations. In addition, static grid adaptations can be successfully used to resolve three-dimensional baroclinic waves in the storm-track region.

  12. Approach for Structurally Clearing an Adaptive Compliant Trailing Edge Flap for Flight

    Science.gov (United States)

    Miller, Eric J.; Lokos, William A.; Cruz, Josue; Crampton, Glen; Stephens, Craig A.; Kota, Sridhar; Ervin, Gregory; Flick, Pete

    2015-01-01

    The Adaptive Compliant Trailing Edge (ACTE) flap was flown on the National Aeronautics and Space Administration (NASA) Gulfstream GIII testbed at the NASA Armstrong Flight Research Center. This smoothly curving flap replaced the existing Fowler flaps creating a seamless control surface. This compliant structure, developed by FlexSys Inc. in partnership with the Air Force Research Laboratory, supported NASA objectives for airframe structural noise reduction, aerodynamic efficiency, and wing weight reduction through gust load alleviation. A thorough structures airworthiness approach was developed to move this project safely to flight. A combination of industry and NASA standard practice require various structural analyses, ground testing, and health monitoring techniques for showing an airworthy structure. This paper provides an overview of compliant structures design, the structural ground testing leading up to flight, and the flight envelope expansion and monitoring strategy. Flight data will be presented, and lessons learned along the way will be highlighted.

  13. The impact of natural transformation on adaptation in spatially structured bacterial populations.

    Science.gov (United States)

    Moradigaravand, Danesh; Engelstädter, Jan

    2014-06-20

    Recent studies have demonstrated that natural transformation and the formation of highly structured populations in bacteria are interconnected. In spite of growing evidence about this connection, little is known about the dynamics of natural transformation in spatially structured bacterial populations. In this work, we model the interdependency between the dynamics of the bacterial gene pool and those of environmental DNA in space to dissect the effect of transformation on adaptation. Our model reveals that even with only a single locus under consideration, transformation with a free DNA fragment pool results in complex adaptation dynamics that do not emerge in previous models focusing only on the gene shuffling effect of transformation at multiple loci. We demonstrate how spatial restriction on population growth and DNA diffusion in the environment affect the impact of transformation on adaptation. We found that in structured bacterial populations intermediate DNA diffusion rates predominantly cause transformation to impede adaptation by spreading deleterious alleles in the population. Overall, our model highlights distinctive evolutionary consequences of bacterial transformation in spatially restricted compared to planktonic bacterial populations.

  14. Fluidic origami: a plant-inspired adaptive structure with shape morphing and stiffness tuning

    Science.gov (United States)

    Li, Suyi; Wang, K. W.

    2015-10-01

    Inspired by the physics behind the rapid plant movements and the rich topologies in origami folding, this research creates a unique class of multi-functional adaptive structure through exploring the innovation of fluidic origami. The idea is to connect multiple Miura folded sheets along their crease lines into a space-filling structure, and fill the tubular cells in-between with working fluids. The pressure and fluid flow in these cells can be strategically controlled much like in plants for nastic movements. The relationship between the internal fluid volume and the overall structure deformation is primarily determined by the kinematics of folding. This relationship can be exploited so that fluidic origami can achieve actuation/morphing by actively changing the internal fluid volume, and stiffness tuning by constraining the fluid volume. In order to characterize the working principles and performance potentials of these two adaptive functions, this research develops an equivalent truss frame model on a fluidic origami unit cell to analyze its fundamental elastic characteristics. Eigen-stiffness analysis based on this model reveals the primary modes of deformation and their relationships with initial folding configurations. Performances of the adaptive functions are correlated to the crease pattern design. In parallel to analytical studies, the feasibility of the morphing and stiffness tuning is also examined experimentally via a 3D printed multi-material prototype demonstrator. The research reported in this paper could lead to the synthesis of adaptive fluidic origami cellular metastructures or metamaterial systems for various engineering applications.

  15. Adaptive solution of some steady-state fluid-structure interaction problems

    International Nuclear Information System (INIS)

    Etienne, S.; Pelletier, D.

    2003-01-01

    This paper presents a general integrated and coupled formulation for modeling the steady-state interaction of a viscous incompressible flow with an elastic structure undergoing large displacements (geometric non-linearities). This constitutes an initial step towards developing a sensitivity analysis formulation for this class of problems. The formulation uses velocity and pressures as unknowns in a flow domain and displacements in the structural components. An interface formulation is presented that leads to clear and simple finite element implementation of the equilibrium conditions at the fluid-solid interface. Issues of error estimation and mesh adaptation are discussed. The adaptive formulation is verified on a problem with a closed form solution. It is then applied to a sample case for which the structure undergoes large displacements induced by the flow. (author)

  16. A New Adaptive Structural Signature for Symbol Recognition by Using a Galois Lattice as a Classifier.

    Science.gov (United States)

    Coustaty, M; Bertet, K; Visani, M; Ogier, J

    2011-08-01

    In this paper, we propose a new approach for symbol recognition using structural signatures and a Galois lattice as a classifier. The structural signatures are based on topological graphs computed from segments which are extracted from the symbol images by using an adapted Hough transform. These structural signatures-that can be seen as dynamic paths which carry high-level information-are robust toward various transformations. They are classified by using a Galois lattice as a classifier. The performance of the proposed approach is evaluated based on the GREC'03 symbol database, and the experimental results we obtain are encouraging.

  17. Enhanced resolution through thick tissue with structured illumination and adaptive optics.

    Science.gov (United States)

    Thomas, Benjamin; Wolstenholme, Adrian; Chaudhari, Snehal N; Kipreos, Edward T; Kner, Peter

    2015-02-01

    Structured illumination microscopy provides twice the linear resolution of conventional fluorescence microscopy, but in thick samples, aberrations degrade the performance and limit the resolution. Here, we demonstrate structured illumination microscopy through 35 μm of tissue using adaptive optics (AO) to correct aberrations resulting in images with a resolution of 140 nm. We report a 60% minimum improvement in the signal-to-noise ratio of the structured illumination reconstruction through thick tissue by correction with AO. © 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)

  18. Asymmetry in Structural Movement: Challenges on the Road to Adaptive Organizational Structures

    National Research Council Canada - National Science Library

    Moomn, Henry; Hollenbeck, John R; Ilgen, Daniel R; West, Bradley; Ellis, Aleks; Humphrey, Stephen; Porter, Christopher

    2000-01-01

    The authors propose that all team based change is not the same. It is offered that change is generally more difficult from divisional to functional structures than it is from functional to divisional structures...

  19. Acute response and chronic stimulus for cardiac structural and functional adaptation in a professional boxer.

    Science.gov (United States)

    Oxborough, David; George, Keith; Utomi, Victor; Lord, Rachel; Morton, James; Jones, Nigel; Somauroo, John

    2014-06-01

    The individual response to acute and chronic changes in cardiac structure and function to intense exercise training is not fully understood and therefore evidence in this setting may help to improve the timing and interpretation of pre-participation cardiac screening. The following case report highlights an acute increase in right ventricular (RV) size and a reduction in left ventricular (LV) basal radial function with concomitant increase at the mid-level in response to a week's increase in training volume in a professional boxer. These adaptations settle by the second week; however, chronic physiological adaptation occurs over a 12-week period. Electrocardiographic findings demonstrate an acute lateral T-wave inversion at 1 week, which revert to baseline for the duration of training. It appears that a change in training intensity and volume generates an acute response within the RV that acts as a stimulus for chronic adaptation in this professional boxer.

  20. Local adaptation in Trinidadian guppies alters stream ecosystem structure at landscape scales despite high environmental variability

    Science.gov (United States)

    Simon, Troy N.; Bassar, Ronald D.; Binderup, Andrew J.; Flecker, Alex S.; Freeman, Mary C.; Gilliam, James F.; Marshall, Michael C.; Thomas, Steve A.; Travis, Joseph; Reznick, David N.; Pringle, Catherine M.

    2017-01-01

    While previous studies have shown that evolutionary divergence alters ecological processes in small-scale experiments, a major challenge is to assess whether such evolutionary effects are important in natural ecosystems at larger spatial scales. At the landscape scale, across eight streams in the Caroni drainage, we found that the presence of locally adapted populations of guppies (Poecilia reticulata) is associated with reduced algal biomass and increased invertebrate biomass, while the opposite trends were true in streams with experimentally introduced populations of non-locally adapted guppies. Exclusion experiments conducted in two separate reaches of a single stream showed that guppies with locally adapted phenotypes significantly reduced algae with no effect on invertebrates, while non-adapted guppies had no effect on algae but significantly reduced invertebrates. These divergent effects of phenotype on stream ecosystems are comparable in strength to the effects of abiotic factors (e.g., light) known to be important drivers of ecosystem condition. They also corroborate the results of previous experiments conducted in artificial streams. Our results demonstrate that local adaptation can produce phenotypes with significantly different effects in natural ecosystems at a landscape scale, within a tropical watershed, despite high variability in abiotic factors: five of the seven physical and chemical parameters measured across the eight study streams varied by more than one order of magnitude. Our findings suggest that ecosystem structure is, in part, an evolutionary product and not simply an ecological pattern.

  1. Adaptive variable structure hierarchical fuzzy control for a class of high-order nonlinear dynamic systems.

    Science.gov (United States)

    Mansouri, Mohammad; Teshnehlab, Mohammad; Aliyari Shoorehdeli, Mahdi

    2015-05-01

    In this paper, a novel adaptive hierarchical fuzzy control system based on the variable structure control is developed for a class of SISO canonical nonlinear systems in the presence of bounded disturbances. It is assumed that nonlinear functions of the systems be completely unknown. Switching surfaces are incorporated into the hierarchical fuzzy control scheme to ensure the system stability. A fuzzy soft switching system decides the operation area of the hierarchical fuzzy control and variable structure control systems. All the nonlinearly appeared parameters of conclusion parts of fuzzy blocks located in different layers of the hierarchical fuzzy control system are adjusted through adaptation laws deduced from the defined Lyapunov function. The proposed hierarchical fuzzy control system reduces the number of rules and consequently the number of tunable parameters with respect to the ordinary fuzzy control system. Global boundedness of the overall adaptive system and the desired precision are achieved using the proposed adaptive control system. In this study, an adaptive hierarchical fuzzy system is used for two objectives; it can be as a function approximator or a control system based on an intelligent-classic approach. Three theorems are proven to investigate the stability of the nonlinear dynamic systems. The important point about the proposed theorems is that they can be applied not only to hierarchical fuzzy controllers with different structures of hierarchical fuzzy controller, but also to ordinary fuzzy controllers. Therefore, the proposed algorithm is more general. To show the effectiveness of the proposed method four systems (two mechanical, one mathematical and one chaotic) are considered in simulations. Simulation results demonstrate the validity, efficiency and feasibility of the proposed approach to control of nonlinear dynamic systems. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  2. MICROSCOPIC, PHYSICOCHEMICAL AND CHROMATOGRAPHIC ...

    African Journals Online (AJOL)

    Peters

    MICROSCOPIC, PHYSICOCHEMICAL AND CHROMATOGRAPHIC. FINGERPRINTS OF LEAVES OF NIGERIAN CASSIA TORA LINN. Fatokun Omolola T1*., EsievoKevwe B2., Ugbabe Grace E3. and Kunle Oluyemisi F4. Department of Medicinal Plant Research and Traditional Medicine, National Institute for.

  3. Physico-chemical properties

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Xenogeneic bone procured from the slaughterhouse waste was deproteinated by heat treatment method intended for use as a bone substitute. The effect of heat treatment was investigated by thermal ana- lysis and by physico-chemical methods such as X-ray powder diffraction (XRD) and Fourier transformed.

  4. Soil physicochemical properties and their significance for ...

    African Journals Online (AJOL)

    Soil physicochemical properties and their significance for sustainable sugarcane production in Kesem Allaideghe plains irrigation project area, Eastern Ethiopia. ... In order to improve soil structure and water availability, addition of gypsum, plant residues and organic matter are recommended. Keywords: Soil survey ...

  5. Interaction of high-speed compressible viscous flow and structure by adaptive finite element method

    International Nuclear Information System (INIS)

    Limtrakarn, Wiroj; Dechaumphai, Pramote

    2004-01-01

    Interaction behaviors of high-speed compressible viscous flow and thermal-structural response of structure are presented. The compressible viscous laminar flow behavior based on the Navier-Stokes equations is predicted by using an adaptive cell-centered finite-element method. The energy equation and the quasi-static structural equations for aerodynamically heated structures are solved by applying the Galerkin finite-element method. The finite-element formulation and computational procedure are described. The performance of the combined method is evaluated by solving Mach 4 flow past a flat plate and comparing with the solution from the finite different method. To demonstrate their interaction, the high-speed flow, structural heat transfer, and deformation phenomena are studied by applying the present method to Mach 10 flow past a flat plate

  6. Dynamic optimization of the complex adaptive controlling by the structure of enterprise’s product range

    Directory of Open Access Journals (Sweden)

    Andrey Fyodorovich Shorikov

    2013-06-01

    Full Text Available This paper reviews a methodical approach to solve multi-step dynamic problem of optimal integrated adaptive management of a product portfolio structure of the enterprise. For the organization of optimal adaptive terminal control of the system the recurrent algorithm, which reduces an initial multistage problem to the realization of the final sequence of problems of optimal program terminal control is offered. In turn, the decision of each problem of optimal program terminal control is reduced to the realization of the final sequence only single-step operations in the form of the problems solving of linear and convex mathematical programming. Thus, the offered approach allows to develop management solutions at current information support, which consider feedback, and which create the optimal structure of an enterprise’s product lines, contributing to optimising of profits, as well as maintenance of the desired level of profit for a long period of time

  7. Relationships between adaptive and neutral genetic diversity and ecological structure and functioning: a meta-analysis

    Science.gov (United States)

    Whitlock, Raj

    2014-01-01

    Understanding the effects of intraspecific genetic diversity on the structure and functioning of ecological communities is a fundamentally important part of evolutionary ecology and may also have conservation relevance in identifying the situations in which genetic diversity coincides with species-level diversity.Early studies within this field documented positive relationships between genetic diversity and ecological structure, but recent studies have challenged these findings. Conceptual synthesis has been hampered because studies have used different measures of intraspecific variation (phenotypically adaptive vs. neutral) and have considered different measures of ecological structure in different ecological and spatial contexts. The aim of this study is to strengthen conceptual understanding by providing an empirical synthesis quantifying the relationship between genetic diversity and ecological structure.Here, I present a meta-analysis of the relationship between genetic diversity within plant populations and the structure and functioning of associated ecological communities (including 423 effect sizes from 70 studies). I used Bayesian meta-analyses to examine (i) the strength and direction of this relationship, (ii) the extent to which phenotypically adaptive and neutral (molecular) measures of diversity differ in their association with ecological structure and (iii) variation in outcomes among different measures of ecological structure and in different ecological contexts.Effect sizes measuring the relationship between adaptive diversity (genotypic richness) and both community- and ecosystem-level ecological responses were small, but significantly positive. These associations were supported by genetic effects on species richness and productivity, respectively.There was no overall association between neutral genetic diversity and measures of ecological structure, but a positive correlation was observed under a limited set of demographic conditions. These

  8. Analysis of the structural design process of the adaptive reuse of building structures

    NARCIS (Netherlands)

    Pasterkamp, S.

    2014-01-01

    In the field of structural building engineering there is a market shift taking place as a result of the growing number of buildings that are listed as cultural heritage, secularization, the economic situation and the increasing office vacancy rate in Europe and the US. More and more structural

  9. New Low Cost Structure for Dual Axis Mount Solar Tracking System Using Adaptive Solar Sensor

    DEFF Research Database (Denmark)

    Argeseanu, Alin; Ritchie, Ewen; Leban, Krisztina Monika

    2010-01-01

    A solar tracking system is designed to optimize the operation of solar energy receivers. The objective of this paper is proposing a new tracking system structure with two axis. The success strategy of this new project focuses on the economical analysis of solar energy. Therefore it is important...... to determine the most cost effective design, to consider the costs of production and maintenance, and operating. The proposed tracking system uses a new solar sensor position with an adaptive feature....

  10. Adaptive Sliding Mode Control of Dynamic Systems Using Double Loop Recurrent Neural Network Structure.

    Science.gov (United States)

    Fei, Juntao; Lu, Cheng

    2018-04-01

    In this paper, an adaptive sliding mode control system using a double loop recurrent neural network (DLRNN) structure is proposed for a class of nonlinear dynamic systems. A new three-layer RNN is proposed to approximate unknown dynamics with two different kinds of feedback loops where the firing weights and output signal calculated in the last step are stored and used as the feedback signals in each feedback loop. Since the new structure has combined the advantages of internal feedback NN and external feedback NN, it can acquire the internal state information while the output signal is also captured, thus the new designed DLRNN can achieve better approximation performance compared with the regular NNs without feedback loops or the regular RNNs with a single feedback loop. The new proposed DLRNN structure is employed in an equivalent controller to approximate the unknown nonlinear system dynamics, and the parameters of the DLRNN are updated online by adaptive laws to get favorable approximation performance. To investigate the effectiveness of the proposed controller, the designed adaptive sliding mode controller with the DLRNN is applied to a -axis microelectromechanical system gyroscope to control the vibrating dynamics of the proof mass. Simulation results demonstrate that the proposed methodology can achieve good tracking property, and the comparisons of the approximation performance between radial basis function NN, RNN, and DLRNN show that the DLRNN can accurately estimate the unknown dynamics with a fast speed while the internal states of DLRNN are more stable.

  11. Enterprise System Adaptation: a Combination of Institutional Structures and Sensemaking Processes

    DEFF Research Database (Denmark)

    Svejvig, Per; Jensen, Tina Blegind

    2009-01-01

    In this paper we set out to investigate how an Enterprise System (ES) adaptation in a Scandinavian high-tech organization, SCANDI, can be understood using a combination of institutional and sensemaking theory. Institutional theory is useful in providing an account for the role that the social...... show: 1) how changing institutional structures provide a shifting context for the way users make sense of and enact ES, 2) how users' sensemaking processes of the ES are played out in practice, and 3) how sensemaking reinforces institutional structures....

  12. Sandwich Structure Risk Reduction in Support of the Payload Adapter Fitting

    Science.gov (United States)

    Nettles, A. T.; Jackson, J. R.; Guin, W. E.

    2018-01-01

    Reducing risk for utilizing honeycomb sandwich structure for the Space Launch System payload adapter fitting includes determining what parameters need to be tested for damage tolerance to ensure a safe structure. Specimen size and boundary conditions are the most practical parameters to use in damage tolerance inspection. The effect of impact over core splices and foreign object debris between the facesheet and core is assessed. Effects of enhanced damage tolerance by applying an outer layer of carbon fiber woven cloth is examined. A simple repair technique for barely visible impact damage that restores all compression strength is presented.

  13. Self-organized emergence of multilayer structure and chimera states in dynamical networks with adaptive couplings

    Science.gov (United States)

    Kasatkin, D. V.; Yanchuk, S.; Schöll, E.; Nekorkin, V. I.

    2017-12-01

    We report the phenomenon of self-organized emergence of hierarchical multilayered structures and chimera states in dynamical networks with adaptive couplings. This process is characterized by a sequential formation of subnetworks (layers) of densely coupled elements, the size of which is ordered in a hierarchical way, and which are weakly coupled between each other. We show that the hierarchical structure causes the decoupling of the subnetworks. Each layer can exhibit either a two-cluster state, a periodic traveling wave, or an incoherent state, and these states can coexist on different scales of subnetwork sizes.

  14. Simultaneous Structural Health Monitoring and Vibration Control of Adaptive Structures Using Smart Materials

    Directory of Open Access Journals (Sweden)

    Myung-Hyun Kim

    2002-01-01

    Full Text Available The integration of actuators and sensors using smart materials enabled various applications including health monitoring and structural vibration control. In this study, a robust control technique is designed and implemented in order to reduce vibration of an active structure. Special attention is given to eliminating the possibility of interaction between the health monitoring system and the control system. Exploiting the disturbance decoupling characteristic of the sliding mode observer, it is demonstrated that the proposed observer can eliminate the possible high frequency excitation from the health monitoring system. At the same time, a damage identification scheme, which tracks the changes of mechanical impedance due to the presence of damage, has been applied to assess the health condition of structures. The main objective of this paper is to examine the potential of combining the two emerging techniques together. Using the collocated piezoelectric sensors/actuators for vibration suppression as well as for health monitoring, this technique enabled to reduce the number of system components, while enhancing the performance of structures. As an initial study, both simulation and experimental investigations were performed for an active beam structure. The results show that this integrated technique can provide substantial vibration reductions, while detecting damage on the structure at the same time.

  15. Physico-chemical study of coating plasma duplex alumina/hydroxyapatite for medical applications relation elaboration/structure/properties(dissolution/adherence/residual constraints)

    International Nuclear Information System (INIS)

    Demonet, N.

    1998-01-01

    The physico-chemical behavior of porous ceramics depositing is studied in order to use them to favour the biological fixing of hip prosthesis fixed without cement. Alumina depositing, hydroxyapatite depositing and duplex (the both together) have been realized by plasma projection on a substrate in Ti-6Al-V. Tests of dissolution have been made. An original method of sound followed by radioactive tracers has allowed to establish an order of phases degradation and to consider the kinetics of calcium ions in function of several parameters of tests. (N.C.)

  16. [Development of a structural equation model for children's adaptation in divorced families].

    Science.gov (United States)

    Shin, Sung Hee

    2010-02-01

    This study was designed to develop and test a structural model for children's adaptation in divorced families. The hypothetical model was constructed based on the Family Resilience Model by McCubbin and McCubbin. Data were collected using self-report questionnaires from 219 children (3-6th grade) in divorced families. The children attended one of 22 community agencies, 8 after-school programs, 3 elementary schools in three cities in South Korea. The collected data were analyzed using LISREL program to test the hypothetical model. The modified model was constructed by deleting four paths in accordance with the statistical and theoretical criteria. Compared to the hypothetical model, the revised one had a better fit to the data. Self-esteem, and beliefs about parental divorce had direct effects, and family communication and internal control had indirect effects on children's adaptation in divorced families. These variables explained 56% of the variance in children's adaptation. The modified model was supported by empirical data. This model could be applied to family nursing interventions with divorced families or any other suffering family transition. When working with children experiencing parental divorce, it is important for nurses to enhance children's self-esteem, family communication and to decrease children's negative beliefs about parental divorce to help in their adaptation.

  17. Three-dimensional structural representation of the sleep-wake adaptability.

    Science.gov (United States)

    Putilov, Arcady A

    2016-01-01

    Various characteristics of the sleep-wake cycle can determine the success or failure of individual adjustment to certain temporal conditions of the today's society. However, it remains to be explored how many such characteristics can be self-assessed and how they are inter-related one to another. The aim of the present report was to apply a three-dimensional structural representation of the sleep-wake adaptability in the form of "rugby cake" (scalene or triaxial ellipsoid) to explain the results of analysis of the pattern of correlations of the responses to the initial 320-item list of a new inventory with scores on the six scales designed for multidimensional self-assessment of the sleep-wake adaptability (Morning and Evening Lateness, Anytime and Nighttime Sleepability, and Anytime and Daytime Wakeability). The results obtained for sample consisting of 149 respondents were confirmed by the results of similar analysis of earlier collected responses of 139 respondents to the same list of 320 items and responses of 1213 respondents to the 72 items of one of the earlier established questionnaire tools. Empirical evidence was provided in support of the model-driven prediction of the possibility to identify items linked to as many as 36 narrow (6 core and 30 mixed) adaptabilities of the sleep-wake cycle. The results enabled the selection of 168 items for self-assessment of all these adaptabilities predicted by the rugby cake model.

  18. Joint U.S./Japan Conference on Adaptive Structures, 1st, Maui, HI, Nov. 13-15, 1990, Proceedings

    Science.gov (United States)

    Wada, Ben K.; Fanson, James L.; Miura, Koryo

    1991-11-01

    The present volume of adaptive structures discusses the development of control laws for an orbiting tethered antenna/reflector system test scale model, the sizing of active piezoelectric struts for vibration suppression on a space-based interferometer, the control design of a space station mobile transporter with multiple constraints, and optimum configuration control of an intelligent truss structure. Attention is given to the formulation of full state feedback for infinite order structural systems, robustness issues in the design of smart structures, passive piezoelectric vibration damping, shape control experiments with a functional model for large optical reflectors, and a mathematical basis for the design optimization of adaptive trusses in precision control. Topics addressed include approaches to the optimal adaptive geometries of intelligent truss structures, the design of an automated manufacturing system for tubular smart structures, the Sandia structural control experiments, and the zero-gravity dynamics of space structures in parabolic aircraft flight.

  19. Evaluation of physicochemical, functional and textural properties of ...

    African Journals Online (AJOL)

    20°C for nine days and six months, respectively, were investigated. The combined effect of proteolytic activity and physicochemical changes in the muscle (pH, solubility and proteolytic activity) altered the molecular structure of the proteins.

  20. Algorithms and data structures for massively parallel generic adaptive finite element codes

    KAUST Repository

    Bangerth, Wolfgang

    2011-12-01

    Today\\'s largest supercomputers have 100,000s of processor cores and offer the potential to solve partial differential equations discretized by billions of unknowns. However, the complexity of scaling to such large machines and problem sizes has so far prevented the emergence of generic software libraries that support such computations, although these would lower the threshold of entry and enable many more applications to benefit from large-scale computing. We are concerned with providing this functionality for mesh-adaptive finite element computations. We assume the existence of an "oracle" that implements the generation and modification of an adaptive mesh distributed across many processors, and that responds to queries about its structure. Based on querying the oracle, we develop scalable algorithms and data structures for generic finite element methods. Specifically, we consider the parallel distribution of mesh data, global enumeration of degrees of freedom, constraints, and postprocessing. Our algorithms remove the bottlenecks that typically limit large-scale adaptive finite element analyses. We demonstrate scalability of complete finite element workflows on up to 16,384 processors. An implementation of the proposed algorithms, based on the open source software p4est as mesh oracle, is provided under an open source license through the widely used deal.II finite element software library. © 2011 ACM 0098-3500/2011/12-ART10 $10.00.

  1. Adapting federated cyberinfrastructure for shared data collection facilities in structural biology

    Energy Technology Data Exchange (ETDEWEB)

    Stokes-Rees, Ian [Harvard Medical School, Boston, MA 02115 (United States); Levesque, Ian [Harvard Medical School, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States); Murphy, Frank V. IV [Argonne National Laboratory, Argonne, IL 60439 (United States); Yang, Wei; Deacon, Ashley [Stanford University, Menlo Park, CA 94025 (United States); Sliz, Piotr, E-mail: piotr-sliz@hms.harvard.edu [Harvard Medical School, Boston, MA 02115 (United States)

    2012-05-01

    It has been difficult, historically, to manage and maintain early-stage experimental data collected by structural biologists in synchrotron facilities. This work describes a prototype system that adapts existing federated cyberinfrastructure technology and techniques to manage collected data at synchrotrons and to facilitate the efficient and secure transfer of data to the owner's home institution. Early stage experimental data in structural biology is generally unmaintained and inaccessible to the public. It is increasingly believed that this data, which forms the basis for each macromolecular structure discovered by this field, must be archived and, in due course, published. Furthermore, the widespread use of shared scientific facilities such as synchrotron beamlines complicates the issue of data storage, access and movement, as does the increase of remote users. This work describes a prototype system that adapts existing federated cyberinfrastructure technology and techniques to significantly improve the operational environment for users and administrators of synchrotron data collection facilities used in structural biology. This is achieved through software from the Virtual Data Toolkit and Globus, bringing together federated users and facilities from the Stanford Synchrotron Radiation Lightsource, the Advanced Photon Source, the Open Science Grid, the SBGrid Consortium and Harvard Medical School. The performance and experience with the prototype provide a model for data management at shared scientific facilities.

  2. Analysis and implementation of a structural vibration control algorithm based on an IIR adaptive filter

    Science.gov (United States)

    Huang, Quanzhen; Luo, Jun; Li, Hengyu; Wang, Xiaohua

    2013-08-01

    With the wide application of large-scale flexible structures in spacecraft, vibration control problems in these structures have become important design issues. The filtered-X least mean square (FXLMS) algorithm is the most popular one in current active vibration control using adaptive filtering. It assumes that the source of interference can be measured and the interference source is considered as the reference signal input to the controller. However, in the actual control system, this assumption is not accurate, because it does not consider the impact of the reference signal on the output feedback signal. In this paper, an adaptive vibration active control algorithm based on an infinite impulse response (IIR) filter structure (FULMS, filtered-U least mean square) is proposed. The algorithm is based on an FXLMS algorithm framework, which replaces the finite impulse response (FIR) filter with an IIR filter. This paper focuses on the structural design of the controller, the process of the FULMS filtering control method, the design of the experimental model object, and the experimental platform construction for the entire control system. The comparison of the FXLMS algorithm with FULMS is theoretically analyzed and experimentally validated. The results show that the FULMS algorithm converges faster and controls better. The design of the FULMS controller is feasible and effective and has greater value in practical applications of aerospace engineering.

  3. Adapting federated cyberinfrastructure for shared data collection facilities in structural biology

    International Nuclear Information System (INIS)

    Stokes-Rees, Ian; Levesque, Ian; Murphy, Frank V. IV; Yang, Wei; Deacon, Ashley; Sliz, Piotr

    2012-01-01

    It has been difficult, historically, to manage and maintain early-stage experimental data collected by structural biologists in synchrotron facilities. This work describes a prototype system that adapts existing federated cyberinfrastructure technology and techniques to manage collected data at synchrotrons and to facilitate the efficient and secure transfer of data to the owner's home institution. Early stage experimental data in structural biology is generally unmaintained and inaccessible to the public. It is increasingly believed that this data, which forms the basis for each macromolecular structure discovered by this field, must be archived and, in due course, published. Furthermore, the widespread use of shared scientific facilities such as synchrotron beamlines complicates the issue of data storage, access and movement, as does the increase of remote users. This work describes a prototype system that adapts existing federated cyberinfrastructure technology and techniques to significantly improve the operational environment for users and administrators of synchrotron data collection facilities used in structural biology. This is achieved through software from the Virtual Data Toolkit and Globus, bringing together federated users and facilities from the Stanford Synchrotron Radiation Lightsource, the Advanced Photon Source, the Open Science Grid, the SBGrid Consortium and Harvard Medical School. The performance and experience with the prototype provide a model for data management at shared scientific facilities

  4. Rapid fully automatic segmentation of subcortical brain structures by shape-constrained surface adaptation.

    Science.gov (United States)

    Wenzel, Fabian; Meyer, Carsten; Stehle, Thomas; Peters, Jochen; Siemonsen, Susanne; Thaler, Christian; Zagorchev, Lyubomir

    2018-03-09

    This work presents a novel approach for the rapid segmentation of clinically relevant subcortical brain structures in T1-weighted MRI by utilizing a shape-constrained deformable surface model. In contrast to other approaches for segmenting brain structures, its design allows for parallel segmentation of individual brain structures within a flexible and robust hierarchical framework such that accurate adaptation and volume computation can be achieved within a minute of processing time. Furthermore, adaptation is driven by local and not global contrast, potentially relaxing requirements with respect to preprocessing steps such as bias-field correction. Detailed evaluation experiments on more than 1000 subjects, including comparisons to FSL FIRST and FreeSurfer as well as a clinical assessment, demonstrate high accuracy and test-retest consistency of the presented segmentation approach, leading, for example, to an average segmentation error of less than 0.5 mm. The presented approach might be useful in both, research as well as clinical routine, for automated segmentation and volume quantification of subcortical brain structures in order to increase confidence in the diagnosis of neuro-degenerative disorders, such as Alzheimer's disease, Parkinson's disease, Multiple Sclerosis, or clinical applications for other neurologic and psychiatric diseases. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Adaptive nonlinear polynomial neural networks for control of boundary layer/structural interaction

    Science.gov (United States)

    Parker, B. Eugene, Jr.; Cellucci, Richard L.; Abbott, Dean W.; Barron, Roger L.; Jordan, Paul R., III; Poor, H. Vincent

    1993-01-01

    The acoustic pressures developed in a boundary layer can interact with an aircraft panel to induce significant vibration in the panel. Such vibration is undesirable due to the aerodynamic drag and structure-borne cabin noises that result. The overall objective of this work is to develop effective and practical feedback control strategies for actively reducing this flow-induced structural vibration. This report describes the results of initial evaluations using polynomial, neural network-based, feedback control to reduce flow induced vibration in aircraft panels due to turbulent boundary layer/structural interaction. Computer simulations are used to develop and analyze feedback control strategies to reduce vibration in a beam as a first step. The key differences between this work and that going on elsewhere are as follows: that turbulent and transitional boundary layers represent broadband excitation and thus present a more complex stochastic control scenario than that of narrow band (e.g., laminar boundary layer) excitation; and secondly, that the proposed controller structures are adaptive nonlinear infinite impulse response (IIR) polynomial neural network, as opposed to the traditional adaptive linear finite impulse response (FIR) filters used in most studies to date. The controllers implemented in this study achieved vibration attenuation of 27 to 60 dB depending on the type of boundary layer established by laminar, turbulent, and intermittent laminar-to-turbulent transitional flows. Application of multi-input, multi-output, adaptive, nonlinear feedback control of vibration in aircraft panels based on polynomial neural networks appears to be feasible today. Plans are outlined for Phase 2 of this study, which will include extending the theoretical investigation conducted in Phase 2 and verifying the results in a series of laboratory experiments involving both bum and plate models.

  6. Structures of HIV-1 gp120 envelope glycoproteins from laboratory-adapted and primary isolates.

    Science.gov (United States)

    Kwong, P D; Wyatt, R; Majeed, S; Robinson, J; Sweet, R W; Sodroski, J; Hendrickson, W A

    2000-12-15

    The gp120 exterior envelope glycoprotein of HIV-1 binds sequentially to CD4 and chemokine receptors on cells to initiate virus entry. During natural infection, gp120 is a primary target of the humoral immune response, and it has evolved to resist antibody-mediated neutralization. We previously reported the structure at 2.5 A of a gp120 core from the HXBc2 laboratory-adapted isolate in complex with a 2 domain fragment of CD4 and the antigen binding fragment of a human antibody. This revealed atomic details of gp120-receptor interactions and suggested multiple mechanisms of immune evasion. We have now extended the HXBc2 structure in P222, crystals to 2.2 A. The enhanced resolution enabled a more accurate modeling of less-well-ordered regions and provided conclusive identification of the density in the central cavity at the crux of the gp120-CD4 interaction as isopropanol from the crystallization medium. We have also determined the structure of a gp120 core from the primary clinical HIV-1 isolate, YU2, in the same ternary complex but in a C2 crystal lattice. Comparisons of HXBc2 and YU2 showed that while CD4 binding was rigid, portions of the gp120 core were conformationally flexible; overall differences were minor, with sequence changes concentrated on a surface expected to be exposed on the envelope oligomer. Despite dramatic antigenic differences between primary and laboratory-adapted HIV-1, the gp120 cores from these isolates are remarkably similar. Taken together with chimeric substitution and sequence analysis, this indicates that neutralization resistance is specified by quaternary interactions involving the major variable loops and thus affords a mechanism for viral adaptation. Conservation of the central cavity suggests the possibility of therapeutic inhibitors. The structures reported here extend in detail and generality our understanding of the biology of the gp120 envelope glycoprotein.

  7. Emergence of a multilayer structure in adaptive networks of phase oscillators

    International Nuclear Information System (INIS)

    Makarov, V.V.; Koronovskii, A.A.; Maksimenko, V.A.; Hramov, A.E.; Moskalenko, O.I.; Buldú, J.M.; Boccaletti, S.

    2016-01-01

    We report on self-organization of adaptive networks, where topology and dynamics evolve in accordance to a competition between homophilic and homeostatic mechanisms, and where links are associated to a vector of weights. Under an appropriate balance between the intra- and inter- layer coupling strengths, we show that a multilayer structure emerges due to the adaptive evolution, resulting in different link weights at each layer, i.e. different components of the weights’ vector. In parallel, synchronized clusters at each layer are formed, which may overlap or not, depending on the values of the coupling strengths. Only when intra- and inter- layer coupling strengths are high enough, all layers reach identical final topologies, collapsing the system into, in fact, a monolayer network. The relationships between such steady state topologies and a set of dynamical network’s properties are discussed.

  8. ADAPTIVE GOP STRUCTURE TO H.264/AVC BASED ON SCENE CHANGE

    Directory of Open Access Journals (Sweden)

    S. Sowmyayani

    2014-08-01

    Full Text Available This paper proposes an adaptive GOP structure with the new logic of frame comparison in H.264/AVC to achieve better quality and reduce bit rate. Initially Group of Pictures (GOP is set to a fixed size. Frames are compared within that GOP using correlation. According to the correlation, GOP is changed within that fixed size. So, there will be no GOP size greater than that fixed size. This method does not calculate any threshold. Hence the time needed to calculate global or local threshold is eliminated. It is integrated with conventional video codec H.264/AVC. This method is compared with H.264/AVC of fixed GOP structure of sizes 4, 8, 12, 16, 32 and GOP structure with the length of entire video. The proposed method achieved gain in bit rate from 0.49% to 69.75% and PSNR gain from 2.5% to 0.3%.

  9. Structural and functional adaptation of the lichens of genus Umbilicaria in rocky habitats of South Karelia

    Directory of Open Access Journals (Sweden)

    Sonina Anzhella Valeryevna

    2015-12-01

    Full Text Available The anatomic and physiological features of species of lichens Umbilicaria deusta and U. hyperborea were studied in South Karelia. The research took place in the tract of Devil's Chair in Petrozavodsk urban district and waste crimson quartzite quarry in Prionezhsky region. The morphology was estimated to be variable and the content of photosynthetic pigments was stable in the thalli of U. deusta. On the contrary, U. hyperborea showed variable photosynthetic pigment content, due to the significant changing all the indicators of photosynthetic apparatus, together with morphological variability. These allowed to reveal two ways in the adaptation of the studied Umbilicaria species: structural - due to the variation of the thickness of mycobiont layers in the species U. deusta; structural and functional - connected with the changes both in the anatomic structures of mycobiont and quantitative indicators of the photosynthetic pigments in photobiont in the species U. hyperborea.

  10. Adaptive pressure-controlled cellular structures for shape morphing I: design and analysis

    International Nuclear Information System (INIS)

    Luo, Quantian; Tong, Liyong

    2013-01-01

    This work investigates adaptive bio-inspired pressure cellular structures for shape morphing. Optimum designs for cellular structures with void and pressure cells are proposed and then structural analyses are conducted. In the present design, a unit cell is comprised of straight and curved walls. When compressed air is pumped into a pressure cell, the curved walls deform in bending due to the pressure difference in two adjacent cells that leads to overall structural deformation in extension. One-dimensional actuation strain up to 35% can be theoretically achieved. In part I, we present basic design concepts and cellular mechanics. Unlike conventional structural analysis for cellular structures, a statically indeterminate unit cell is considered and novel analytical formulations are derived for the present pressurized cellular structures in linear and nonlinear analyses. In part II, we will present experimental testing and finite element analysis to demonstrate the feasibility of the present pressurized cellular actuators for morphing wings and to validate the present cellular mechanics formulations. (paper)

  11. Adapting the Structural Family Systems Rating to Assess the Patterns of Interaction in Families of Dementia Caregivers

    Science.gov (United States)

    Mitrani, Victoria B.; Feaster, Daniel J.; McCabe, Brian E.; Czaja, Sara J.; Szapocznik, Jose

    2005-01-01

    Purpose: This study adapted the Structural Family Systems Ratings (SFSR), an observational measure of family interactions, for dementia caregivers. This article presents the development of the SFSR-Dementia Caregiver adaptation (SFSR-DC) and examines relationships between specific family-interaction patterns and caregiver distress. Design and…

  12. Adaptive cellular structures and devices with internal features for enhanced structural performance

    Science.gov (United States)

    Pontecorvo, Michael Eugene

    This dissertation aims to develop a family of cellular and repeatable devices that exhibit a variety of force-displacement behaviors. It is envisioned that these cellular structures might be used either as stand-alone elements, or combined and repeated to create multiple types of structures (i.e. buildings, ship hulls, vehicle subfloors, etc.) with the ability to passively or actively perform multiple functions (harmonic energy dissipation, impact mitigation, modulus change) over a range of loading types, amplitudes, and frequencies. To accomplish this goal, this work combines repeatable structural frameworks, such as that provided by a hexagonal cellular structure, with internal structural elements such as springs, viscous dampers, buckling plates, bi-stable von Mises trusses (VMTs), and pneumatic artificial muscles (PAMs). The repeatable framework serves to position damping and load carrying elements throughout the structure, and the configuration of the internal elements allow each cell to be tuned to exhibit a desired force-displacement response. Therefore, gradient structures or structures with variable load paths can be created for an optimal global response to a range of loads. This dissertation focuses on the development of cellular structures for three functions: combined load-carrying capability with harmonic energy dissipation, impact mitigation, and cell modulus variation. One or more conceptual designs are presented for devices that can perform each of these functions, and both experimental measurements and simulations are used to gain a fundamental understanding of each device. Chapter 2 begins with a presentation of a VMT model that is the basis for many of the elements. The equations of motion for the VMT are derived and the static and dynamic behavior of the VMT are discussed in detail. Next, two metrics for the energy dissipation of the VMT - hysteresis loop area and loss factor - are presented. The responses of the VMT to harmonic displacement

  13. Development of structural correlations and synchronization from adaptive rewiring in networks of Kuramoto oscillators

    Science.gov (United States)

    Papadopoulos, Lia; Kim, Jason Z.; Kurths, Jürgen; Bassett, Danielle S.

    2017-07-01

    Synchronization of non-identical oscillators coupled through complex networks is an important example of collective behavior, and it is interesting to ask how the structural organization of network interactions influences this process. Several studies have explored and uncovered optimal topologies for synchronization by making purposeful alterations to a network. On the other hand, the connectivity patterns of many natural systems are often not static, but are rather modulated over time according to their dynamics. However, this co-evolution and the extent to which the dynamics of the individual units can shape the organization of the network itself are less well understood. Here, we study initially randomly connected but locally adaptive networks of Kuramoto oscillators. In particular, the system employs a co-evolutionary rewiring strategy that depends only on the instantaneous, pairwise phase differences of neighboring oscillators, and that conserves the total number of edges, allowing the effects of local reorganization to be isolated. We find that a simple rule—which preserves connections between more out-of-phase oscillators while rewiring connections between more in-phase oscillators—can cause initially disordered networks to organize into more structured topologies that support enhanced synchronization dynamics. We examine how this process unfolds over time, finding a dependence on the intrinsic frequencies of the oscillators, the global coupling, and the network density, in terms of how the adaptive mechanism reorganizes the network and influences the dynamics. Importantly, for large enough coupling and after sufficient adaptation, the resulting networks exhibit interesting characteristics, including degree-frequency and frequency-neighbor frequency correlations. These properties have previously been associated with optimal synchronization or explosive transitions in which the networks were constructed using global information. On the contrary, by

  14. Vibrational behavior of adaptive aircraft wing structures modelled as composite thin-walled beams

    Science.gov (United States)

    Song, O.; Librescu, L.; Rogers, C. A.

    1992-01-01

    The vibrational behavior of cantilevered aircraft wings modeled as thin-walled beams and incorporating piezoelectric effects is studied. Based on the converse piezoelectric effect, the system of piezoelectric actuators conveniently located on the wing yield the control of its associated vertical and lateral bending eigenfrequencies. The possibility revealed by this study enabling one to increase adaptively the eigenfrequencies of thin-walled cantilevered beams could play a significant role in the control of the dynamic response and flutter of wing and rotor blade structures.

  15. An adaptive structure data acquisition system using a graphical-based programming language

    Science.gov (United States)

    Baroth, Edmund C.; Clark, Douglas J.; Losey, Robert W.

    1992-01-01

    An example of the implementation of data fusion using a PC and a graphical programming language is discussed. A schematic of the data acquisition system and user interface panel for an adaptive structure test are presented. The computer programs (a series of icons 'wired' together) are also discussed. The way in which using graphical-based programming software to control a data acquisition system can simplify analysis of data, promote multidisciplinary interaction, and provide users a more visual key to understanding their data are shown.

  16. A Bayesian Network Based Adaptability Design of Product Structures for Function Evolution

    Directory of Open Access Journals (Sweden)

    Shaobo Li

    2018-03-01

    Full Text Available Structure adaptability design is critical for function evolution in product families, in which many structural and functional design factors are intertwined together with manufacturing cost, customer satisfaction, and final market sales. How to achieve a delicate balance among all of these factors to maximize the market performance of the product is too complicated to address based on traditional domain experts’ knowledge or some ad hoc heuristics. Here, we propose a quantitative product evolution design model that is based on Bayesian networks to model the dynamic relationship between customer needs and product structure design. In our model, all of the structural or functional features along with customer satisfaction, manufacturing cost, sale price, market sales, and indirect factors are modeled as random variables denoted as nodes in the Bayesian networks. The structure of the Bayesian model is then determined based on the historical data, which captures the dynamic sophisticated relationship of customer demands of a product, structural design, and market performance. Application of our approach to an electric toothbrush product family evolution design problem shows that our model allows for designers to interrogate with the model and obtain theoretical and decision support for dynamic product feature design process.

  17. Antibacterial Barbituric Acid Analogues Inspired from Natural 3-Acyltetramic Acids; Synthesis, Tautomerism and Structure and Physicochemical Property-Antibacterial Activity Relationships

    Directory of Open Access Journals (Sweden)

    Yong-Chul Jeong

    2015-02-01

    Full Text Available The synthesis, tautomerism and antibacterial activity of novel barbiturates is reported. In particular, 3-acyl and 3-carboxamidobarbiturates exhibited antibacterial activity, against susceptible and some resistant Gram-positive strains of particular interest is that these systems possess amenable molecular weight, rotatable bonds and number of proton-donors/acceptors for drug design as well as less lipophilic character, with physicochemical properties and ionic states that are similar to current antibiotic agents for oral and injectable use. Unfortunately, the reduction of plasma protein affinity by the barbituric core is not sufficient to achieve activity in vivo. Further optimization to reduce plasma protein affinity and/or elevate antibiotic potency is therefore required, but we believe that these systems offer unusual opportunities for antibiotic drug discovery.

  18. 1H and 13C NMR spectra, structure and physicochemical features of phenyl acridine-9-carboxylates and 10-methyl-9-(phenoxycarbonyl)acridinium trifluoromethanesulphonates--alkyl substituted in the phenyl fragment.

    Science.gov (United States)

    Krzymiński, K; Malecha, P; Zadykowicz, B; Wróblewska, A; Błażejowski, J

    2011-01-01

    The 1H and 13C NMR spectra of twelve phenyl acridine-9-carboxylates--alkyl-substituted in the phenyl fragment--and their 10-methyl-9-(phenoxycarbonyl)acridinium salts dissolved in CD3CN, CD3OD, CDCl3 and DMSO-d6 were recorded in order to examine the influence of the structure of these compounds and the properties of the solvents on chemical shifts and 1H-(1)H coupling constants. Experimental data were compared with 1H and 13C chemical shifts predicted at the GIAO/DFT level of theory for DFT(B3LYP)/6-31G** optimised geometries of molecules, as well as with values of 1H chemical shifts and 1H-(1)H coupling constants, estimated using ACD/HNMR database software to ensure that the assignment was correct. To investigate the relations between chemical shifts and selected structural or physicochemical characteristics of the target compounds, the values of several of these parameters were determined at the DFT or HF levels of theory. The HOMO and LUMO energies obtained at the HF level yielded the ionisation potentials and electron affinities of molecules. The DFT method provided atomic partial charges, dipole moments, LCAO coefficients of pz LUMO of selected C atoms, and angles reflecting characteristic structural features of the compounds. It was found that the experimentally determined 1H and 13C chemical shifts of certain atoms relate to the predicted dipole moments, the angles between the acridine and phenyl moieties, and the LCAO coefficients of the pz LUMO of the C atoms believed to participate in the initial step of the oxidation of the target compounds. The spectral and physicochemical characteristics of the target compounds were investigated in the context of their chemiluminogenic ability. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. The network structure of adaptive governance - A single case study of a fish management area

    Directory of Open Access Journals (Sweden)

    Annica Charlotte Sandström

    2009-09-01

    Full Text Available The challenge of establishing adaptive management systems is a widely discussed topic in the literature on natural resource management. Adaptive management essentially focuses on achieving a governance process that is both sensitive to and has the capacity to continuously react to changes within the ecosystem being managed. The adoption of a network approach that perceives governance structures as social networks, searching for the kind of network features promoting this important feature, has been requested by researchers in the field. In particular, the possibilities associated with the application of a formal network approach, using the tools and concepts of social network analysis (SNA, have been identified as having significant potential for advancing this branch of research. This paper aims to address the relation between network structure and adaptability using an empirical approach. With the point of departure in a previously generated theoretical framework as well as related hypotheses, this paper presents a case study of a governance process within a fish management area in Sweden. The hypotheses state that, although higher levels of network density and centralisation promote the rule-forming process, the level of network heterogeneity is important for the existence and spread of ecological knowledge among the actors involved. According to the empirical results, restricted by the single-case study design, this assumption is still a well-working hypothesis. However, in order to advance our knowledge concerning these issues and test the validity of the hypotheses, more empirical work using a similar approach in multiple case study designs is needed.

  20. PACS—Realization of an adaptive concept using pressure actuated cellular structures

    International Nuclear Information System (INIS)

    Gramüller, B; Boblenz, J; Hühne, C

    2014-01-01

    A biologically inspired concept is investigated which can be utilized to develop energy efficient, lightweight and applicational flexible adaptive structures. Building a real life morphing unit is an ambitious task as the numerous works in the particular field show. Summarizing fundamental demands and barriers regarding shape changing structures, the basic challenges of designing morphing structures are listed. The concept of Pressure Actuated Cellular Structures (PACS) is arranged within the recent morphing activities and it is shown that it complies with the underlying demands. Systematically divided into energy-related and structural subcomponents the working principle is illuminated and relationships between basic design parameters are expressed. The analytical background describing the physical mechanisms of PACS is presented in concentrated manner. This work focuses on the procedure of dimensioning, realizing and experimental testing of a single cell and a single row cantilever made of PACS. The experimental outcomes as well as the results from the FEM computations are used for evaluating the analytical methods. The functionality of the basic principle is thus validated and open issues are determined pointing the way ahead. (paper)

  1. Brain structural changes following adaptive cognitive training assessed by Tensor-Based Morphometry (TBM).

    Science.gov (United States)

    Colom, Roberto; Hua, Xue; Martínez, Kenia; Burgaleta, Miguel; Román, Francisco J; Gunter, Jeffrey L; Carmona, Susanna; Jaeggi, Susanne M; Thompson, Paul M

    2016-10-01

    Tensor-Based Morphometry (TBM) allows the automatic mapping of brain changes across time building 3D deformation maps. This technique has been applied for tracking brain degeneration in Alzheimer's and other neurodegenerative diseases with high sensitivity and reliability. Here we applied TBM to quantify changes in brain structure after completing a challenging adaptive cognitive training program based on the n-back task. Twenty-six young women completed twenty-four training sessions across twelve weeks and they showed, on average, large cognitive improvements. High-resolution MRI scans were obtained before and after training. The computed longitudinal deformation maps were analyzed for answering three questions: (a) Are there differential brain structural changes in the training group as compared with a matched control group? (b) Are these changes related to performance differences in the training program? (c) Are standardized changes in a set of psychological factors (fluid and crystallized intelligence, working memory, and attention control) measured before and after training, related to structural changes in the brain? Results showed (a) greater structural changes for the training group in the temporal lobe, (b) a negative correlation between these changes and performance across training sessions (the greater the structural change, the lower the cognitive performance improvements), and (c) negligible effects regarding the psychological factors measured before and after training. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Subversion of innate and adaptive immune activation induced by structurally modified lipopolysaccharide from Salmonella typhimurium.

    Science.gov (United States)

    Pastelin-Palacios, Rodolfo; Gil-Cruz, Cristina; Pérez-Shibayama, Christian I; Moreno-Eutimio, Mario A; Cervantes-Barragán, Luisa; Arriaga-Pizano, Lourdes; Ludewig, Burkhard; Cunningham, Adam F; García-Zepeda, Eduardo A; Becker, Ingeborg; Alpuche-Aranda, Celia; Bonifaz, Laura; Gunn, John S; Isibasi, Armando; López-Macías, Constantino

    2011-08-01

    Salmonella are successful pathogens that infect millions of people every year. During infection, Salmonella typhimurium changes the structure of its lipopolysaccharide (LPS) in response to the host environment, rendering bacteria resistant to cationic peptide lysis in vitro. However, the role of these structural changes in LPS as in vivo virulence factors and their effects on immune responses and the generation of immunity are largely unknown. We report that modified LPS are less efficient than wild-type LPS at inducing pro-inflammatory responses. The impact of this LPS-mediated subversion of innate immune responses was demonstrated by increased mortality in mice infected with a non-lethal dose of an attenuated S. typhimurium strain mixed with the modified LPS moieties. Up-regulation of co-stimulatory molecules on antigen-presenting cells and CD4(+) T-cell activation were affected by these modified LPS. Strains of S. typhimurium carrying structurally modified LPS are markedly less efficient at inducing specific antibody responses. Immunization with modified LPS moiety preparations combined with experimental antigens, induced an impaired Toll-like receptor 4-mediated adjuvant effect. Strains of S. typhimurium carrying structurally modified LPS are markedly less efficient at inducing immunity against challenge with virulent S. typhimurium. Hence, changes in S. typhimurium LPS structure impact not only on innate immune responses but also on both humoral and cellular adaptive immune responses. © 2011 The Authors. Immunology © 2011 Blackwell Publishing Ltd.

  3. New Design Method of UWB Microstrip Filters Using Adaptive Genetic Algorithms with Defected Ground Structures

    Directory of Open Access Journals (Sweden)

    Amir Reza Dastkhosh

    2010-01-01

    Full Text Available The effects of adaptive genetic algorithms (AGAs and defected ground structures (DGSs on performance optimization of tapered microstrip filter are investigated. The proposed structure achieves an ultra wide stopband with high attenuation within a small surface area, as well as 45% smaller size, in comparison with conventional filters. The parameters of the filter are optimized using in-home AGA code. In the proposed AGA algorithm, the crossover and mutation probabilities are adaptively changed according to the value of individual fitness. Then by utilizing the proposed DGS, a compact S-band lowpass filter with ultra-wide spurious free window is obtained. The proposed filter achieves an insertion loss of 0.8 dB from DC up to 4 GHz and 21 dB rejection in the stopband from 4.3 up to 60 GHz. The fabricated and measured results exhibit good agreement with the simulated results. They demonstrate that combining AGA and DGS yields best possible response for this group of filters.

  4. Towards Global Jihadism: Al-Qaeda's Strategic, Ideological and Structural Adaptations since 9/11

    Directory of Open Access Journals (Sweden)

    Bill Braniff

    2011-05-01

    Full Text Available In recent years, Al-Qaeda has suffered a number of setbacks, but has also successfully spawned an expansionist global jihadist movement that will survive the death of Osama bin Laden. This article describes how the multifaceted threat posed by global jihadism has evolved over the last decade. It first recounts some of the more salient examples of Al-Qaeda’s post-9/11 strategic, ideological, and structural adaptations, and then offers a balance sheet of Al-Qaeda’s contemporary strengths and weaknesses. Al-Qaeda continues to enable the violence of others, orient that violence towards the United States and its allies in a distributed game of attrition warfare, and foster a dichotomous “us versus them” narrative between the Muslim world and the rest of the international community. Despite this overarching consistency, Al-Qaeda shepherds a different phenomenon than it did ten years ago. The aggregation of the movement’s strategic, ideological, and structural adaptations has fundamentally changed the nature of the jihadist threat to the West. This evolved threat is not inherently more dangerous, as counterterrorism efforts today focus on and disrupt capability earlier and more consistently than prior to September 2001. This multifaceted global jihad will, however, continue to produce greater numbers of attacks in more locations, from a more diverse cadre of individuals spanning a wider ideological spectrum.   

  5. A new user-adapted search haptic algorithm to navigate along filiform structures.

    Science.gov (United States)

    Raya, Laura; Bayona, Sofia; Pastor, Luis; Garcia, Marcos

    2014-01-01

    One of the mayor research challenges of this century is the understanding of the human brain. Regarding this field line, simulation based research is gaining importance. A large amount of money is being spent in huge international projects such as The Human Brain Project [1] and The Blue Brain [2]. The behavior of the brain and, therefore, the behavior of brain simulations depend to a large extend on the neural topology. Neural elements are organized in a connected, dense, complex network of thread-like (i.e., filiform) structures. The analysis of a computer-based simulation using just the visual modality is a highly complex task due to the complexity of the neural topology and the large amounts of multi-variable and multi-modal data generated by computer simulations. In this paper, we propose the use of haptic devices to aid in the navigation along these neural structures, helping neurobiologists in the analysis of neural network topologies. However, haptic navigation constrained to complex filiform networks entails problems when these structures have high frequency features, noise and/or complex branching nodes. We address these issues by presenting a new user-adapted search haptic method that uses the forces exerted by the users to infer their intentions. In addition, we propose a specific calibration technique to adapt the haptic navigation to the user's skills and to the data. We validate this approach through a perceptual study. Finally, we show in this paper the application of our method to the analysis of dense and complex filiform structures in the neurobiology context. Additionally, our technique could be applied to other problems such as electronic circuits and graph exploration.

  6. Open Source Tools for Adaptive Simulation of Fluid-Structure Interaction Processes

    Science.gov (United States)

    Kees, C. E.; Quezada de Luna, M.; Zhang, A.; Rakhsha, M.; de Lataillade, T.; Dimakopoulos, A.

    2017-12-01

    Surface and shallow subsurface structures often play critical roles incontrolling hydrological processes as well as in determining theperformance of large-scale civil works projects, such as flood andcoastal storm protection systems. Reliably predicting performance ofsuch structures requires coupling to larger scale models and fielddata for the hydraulic forcing while sometimes resolving down toscales ranging from meters to millimeters. These scales are dictatedby accuracy considerations specific to the analysis and processes inquestion. The hydraulics are often inherently three-dimensional andinvolve complex free-surface dynamics coupled to dynamic structuralresponse. In this presentation we will present recent work oncombining unstructured finite element methods with dynamicallyadaptive meshing tools to achieve simulation of structural responseunder surface and subsurface hydraulic forcing. The approach combinesseveral techniques, including dynamically redistributing boundaryfitted meshes (Arbitrary Lagrangian Eulerian methods), employingimmersed boundary approximations, and locally adapting computationalmeshes to achieve robust and and high-fidelity fluid-solid interactiondynamics at a reasonable computational cost. A key technologyunderpinning the approach is a stabilized finite element method forincompressible free-surface flows, which generalizes to higher-orderand is designed to minimize dependence on arbitrary parameters andmesh sensitivity while achieving qualitatively correct features suchas mass/volume conservation and discrete maximum principles. Aposteriori error estimates based on these qualitative features andunderlying velocity field accuracy are used to drive the meshadaptivity. Several estimates are being assessed on a range ofverification and validation problems for structures of interest invarious wave and hydraulic climates. The algorithms are combined inthe open source Proteus toolkit in order to provide a framework forbuilding parallel

  7. Physico-chemical properties of South American iguanid albumins.

    Science.gov (United States)

    Higgins, P J

    1980-12-15

    Except for a markedly reduced anodal electrophoretic mobility, the serum of the Galapagos marine iguana was physico-chemically identical to that of terrestrial iguanids. Reduction in albumin net charge may have facilitated the adaptation of this species to a semi-aquatic environment.

  8. Comparison of traditional physico-chemical methods and molecular ...

    African Journals Online (AJOL)

    This study was aim to review the efficiency of molecular markers and traditional physico-chemical methods for the identification of basmati rice. The study involved 44 promising varieties of Indica rices collected from geographically distant places and adapted to irrigated and aerobic agro-ecosystems. Quality data for ...

  9. Effect of ultrasound treatment on the wet heating Maillard reaction between mung bean [Vigna radiate (L.)] protein isolates and glucose and on structural and physico-chemical properties of conjugates.

    Science.gov (United States)

    Wang, Zhongjiang; Han, Feifei; Sui, Xiaonan; Qi, Baokun; Yang, Yong; Zhang, Hui; Wang, Rui; Li, Yang; Jiang, Lianzhou

    2016-03-30

    The objective of this study was to determine the effect of ultrasound treatment on the wet heating Maillard reaction between mung bean protein isolates (MBPIs) and glucose, and on structural and physico-chemical properties of the conjugates. The degree of glycosylation of MBPI-glucose conjugates treated by ultrasound treatment and wet heating (MBPI-GUH) was higher than that of MBPI-glucose conjugates only treated by wet heating (MBPI-GH). Solubility, emulsification activity, emulsification stability and surface hydrophobicity of MBPI-GUH were higher than that of MBPI-GH. Grafted MBPIs had a lower content of α-helix and unordered coil, but a higher content of β-sheet and β-turn structure than MBPIs. No significant structural changes were observed in β-turn and random coil structure of MBPI-GUH, while α-helix content increased with ultrasonic time, and decreased at 300 W ultrasonic power with the increase of β-sheet. MBPI-GUH had a less compact tertiary structure compared to MBPI-GH and MBPI. Grafting MBPIs with glucose formed conjugates of higher molecular weight, while no significant changes were observed in electrophoresis profiles of MBPI-GUH. Ultrasound-assisted wet heating Maillard reaction between MBPIs and glucose could be a promising way to improve functional properties of MBPIs. © 2015 Society of Chemical Industry.

  10. Collaboratively Adaptive Vibration Sensing System for High-fidelity Monitoring of Structural Responses Induced by Pedestrians

    Directory of Open Access Journals (Sweden)

    Shijia Pan

    2017-05-01

    Full Text Available This paper presents a collaboratively adaptive vibration monitoring system that captures high-fidelity structural vibration signals induced by pedestrians. These signals can be used for various human activities’ monitoring by inferring information about the impact sources, such as pedestrian footsteps, door opening and closing, and dragging objects. Such applications often require high-fidelity (high resolution and low distortion signals. Traditionally, expensive high resolution and high dynamic range sensors are adopted to ensure sufficient resolution. However, for sensing systems that use low-cost sensing devices, the resolution and dynamic range are often limited; hence this type of sensing methods is not well explored ubiquitously. We propose a low-cost sensing system that utilizes (1 a heuristic model of the investigating excitations and (2 shared information through networked devices to adapt hardware configurations and obtain high-fidelity structural vibration signals. To further explain the system, we use indoor pedestrian footstep sensing through ambient structural vibration as an example to demonstrate the system performance. We evaluate the application with three metrics that measure the signal quality from different aspects: the sufficient resolution rate to present signal resolution improvement without clipping, the clipping rate to measure the distortion of the footstep signal, and the signal magnitude to quantify the detailed resolution of the detected footstep signal. In experiments conducted in a school building, our system demonstrated up to 2× increase on the sufficient resolution rate and 2× less error rate when used to locate the pedestrians as they walk along the hallway, compared to a fixed sensing setting.

  11. The adaptation of polar fishes to climatic changes: Structure, function and phylogeny of haemoglobin.

    Science.gov (United States)

    Verde, Cinzia; Giordano, Daniela; di Prisco, Guido

    2008-01-01

    In the Antarctic, fishes of dominant suborder Notothenioidei have evolved in a unique thermal scenario. Phylogenetically related taxa of the suborder live in a wide range of latitudes, in Antarctic, sub-Antarctic and temperate oceans. Consequently, they offer a remarkable opportunity to study the physiological and biochemical characters gained and, conversely, lost during their evolutionary history. The evolutionary perspective has also been pursued by comparative studies of some features of the heme protein devoted to O(2) transport in fish living in the other polar region, the Arctic. The two polar regions differ by age and isolation. Fish living in each habitat have undergone regional constraints and fit into different evolutionary histories. The aim of this contribution is to survey the current knowledge of molecular structure, functional features, phylogeny and adaptations of the haemoglobins of fish thriving in the Antarctic, sub-Antarctic and Arctic regions (with some excursions in the temperate latitudes), in search of insights into the convergent processes evolved in response to cooling. Current climate change may disturb adaptation, calling for strategies aimed at neutralising threats to biodiversity.

  12. Microgeographical population structure and adaptation in Atlantic cod Gadus morhua: spatio-temporal insights from gene-associated DNA markers

    DEFF Research Database (Denmark)

    Poulsen, Nina Aagaard; Hemmer-Hansen, Jakob; Loeschcke, V.

    2011-01-01

    populations, indicating long-term temporal adaptive stability driven by strong local selection. In an environmentally dynamic area, on the other hand, patterns of genetic structuring were more variable. Overall, our results not only suggest separation of populations under both evolutionary and ecological...... paradigms, but also illustrate the usefulness of the spatio-temporal approach for making inferences about the dynamics and geographical distribution of adaptive genetic variation in natural populations.......Recent technical advances have stimulated studies on spatial scales of adaptive genetic variation in marine fishes. However, very few studies have combined spatial and temporal sampling to investigate adaptive genetic structuring at local and microgeographical scales, i.e. scales at which neutral...

  13. Electronic Structure Calculations and Adaptation Scheme in Multi-core Computing Environments

    Energy Technology Data Exchange (ETDEWEB)

    Seshagiri, Lakshminarasimhan; Sosonkina, Masha; Zhang, Zhao

    2009-05-20

    Multi-core processing environments have become the norm in the generic computing environment and are being considered for adding an extra dimension to the execution of any application. The T2 Niagara processor is a very unique environment where it consists of eight cores having a capability of running eight threads simultaneously in each of the cores. Applications like General Atomic and Molecular Electronic Structure (GAMESS), used for ab-initio molecular quantum chemistry calculations, can be good indicators of the performance of such machines and would be a guideline for both hardware designers and application programmers. In this paper we try to benchmark the GAMESS performance on a T2 Niagara processor for a couple of molecules. We also show the suitability of using a middleware based adaptation algorithm on GAMESS on such a multi-core environment.

  14. The Basic Empathy Scale adapted to French middle childhood: Structure and development of empathy.

    Science.gov (United States)

    Bensalah, Leila; Stefaniak, Nicolas; Carre, Arnaud; Besche-Richard, Chrystel

    2016-12-01

    We adapted the adult French version of the Basic Empathy Scale to French children aged 6-11 years, in order to probe the factorial structure underlying empathy. A total of 410 children (189 girls and 221 boys) were instructed to fill out the resulting Basic Empathy Scale in Children (BES-C). Results showed that, as in adulthood, the three-factor model of empathy (i.e., emotional contagion, cognitive empathy, and emotional disconnection) was more relevant than the one- and two-factor ones. This means that as early as 6 years of age, children's responses should reflect the same organization of the three components of empathy as those of adults. In line with the literature, cognitive empathy increased and emotional disconnection decreased in middle childhood, while emotional contagion remained stable. Moreover, girls exhibited greater emotional contagion than boys, with the reverse pattern being observed for emotional disconnection. No sex difference was found regarding cognitive empathy.

  15. An adaptive Bayesian inversion for upper mantle structure using surface waves and scattered body waves

    Science.gov (United States)

    Eilon, Zachary; Fischer, Karen M.; Dalton, Colleen A.

    2018-04-01

    We present a methodology for 1-D imaging of upper mantle structure using a Bayesian approach that incorporates a novel combination of seismic data types and an adaptive parameterisation based on piecewise discontinuous splines. Our inversion algorithm lays the groundwork for improved seismic velocity models of the lithosphere and asthenosphere by harnessing the recent expansion of large seismic arrays and computational power alongside sophisticated data analysis. Careful processing of P- and S-wave arrivals isolates converted phases generated at velocity gradients between the mid-crust and 300 km depth. This data is allied with ambient noise and earthquake Rayleigh wave phase velocities to obtain detailed VS and VP velocity models. Synthetic tests demonstrate that converted phases are necessary to accurately constrain velocity gradients, and S-p phases are particularly important for resolving mantle structure, while surface waves are necessary for capturing absolute velocities. We apply the method to several stations in the northwest and north-central United States, finding that the imaged structure improves upon existing models by sharpening the vertical resolution of absolute velocity profiles, offering robust uncertainty estimates, and revealing mid-lithospheric velocity gradients indicative of thermochemical cratonic layering. This flexible method holds promise for increasingly detailed understanding of the upper mantle.

  16. Plant-inspired adaptive structures and materials for morphing and actuation: a review.

    Science.gov (United States)

    Li, Suyi; Wang, K W

    2016-12-20

    Plants exhibit a variety of reversible motions, from the slow opening of pine cones to the impulsive closing of Venus flytrap leaves. These motions are achieved without muscles and they have inspired a wide spectrum of engineered materials and structures. This review summarizes the recent developments of plant-inspired adaptive structures and materials for morphing and actuation. We begin with a brief overview of the actuation strategies and physiological features associated to these plant movements, showing that different combinations of these strategies and features can lead to motions with different deformation characteristics and response speeds. Then we offer a comprehensive survey of the plant-inspired morphing and actuation systems, including pressurized cellular structures, osmotic actuation, anisotropic hygroscopic materials, and bistable systems for rapid movements. Although these engineered systems are vastly different in terms of their size scales and intended applications, their working principles are all related to the actuation strategies and physiological features in plants. This review is to promote future cross-disciplinary studies between plant biology and engineering, which can foster new solutions for many applications such as morphing airframes, soft robotics and kinetic architectures.

  17. In Situ Polymorphic Alteration of Filler Structures for Biomimetic Mechanically Adaptive Elastomer Nanocomposites.

    Science.gov (United States)

    Natarajan, Tamil Selvan; Okamoto, Shigeru; Stöckelhuber, Klaus Werner; Wießner, Sven; Reuter, Uta; Fischer, Dieter; Ghosh, Anik Kumar; Heinrich, Gert; Das, Amit

    2018-04-30

    A mechanically adaptable elastomer composite is prepared with reversible soft-stiff properties that can be easily controlled. By the exploitation of different morphological structures of calcium sulfate, which acts as the active filler in a soft elastomer matrix, the magnitude of filler reinforcement can be reversibly altered, which will be reflected in changes of the final stiffness of the material. The higher stiffness, in other words, the higher modulus of the composites, is realized by the in situ development of fine nanostructured calcium sulfate dihydrate crystals, which are formed during exposure to water and, further, these highly reinforcing crystals can be transformed to a nonreinforcing hemihydrate mesocrystalline structure by simply heating the system in a controlled way. The Young's modulus of the developed material can be reversibly altered from ∼6 to ∼17 MPa, and the dynamic stiffness (storage modulus at room temperature and 10 Hz frequency) alters its value in the order of 1000%. As the transformation is related to the presence of water molecules in the crystallites, a hydrophilic elastomer matrix was selected, which is a blend of two hydrophilic polymers, namely, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer and a terpolymer of ethylene oxide-propylene oxide-allyl glycidyl ether. For the first time, this method also provides a route to regulate the morphology and structure of calcium sulfate nanocrystals in a confined ambient of cross-linked polymer chains.

  18. Structural Changes Associated with Delayed Dark Adaptation in Age-Related Macular Degeneration.

    Science.gov (United States)

    Laíns, Inês; Miller, John B; Park, Dong H; Tsikata, Edem; Davoudi, Samaneh; Rahmani, Safa; Pierce, Jonathan; Silva, Rufino; Chen, Teresa C; Kim, Ivana K; Vavvas, Demetrios; Miller, Joan W; Husain, Deeba

    2017-09-01

    To examine the relationship between dark adaptation (DA) and optical coherence tomography (OCT)-based macular morphology in age-related macular degeneration (AMD). Prospective, cross-sectional study. Patients with AMD and a comparison group (>50 years) without any vitreoretinal disease. All participants were imaged with spectral-domain OCT and color fundus photographs, and then staged for AMD (Age-related Eye Disease Study system). Both eyes were tested with the AdaptDx (MacuLogix, Middletown, PA) DA extended protocol (20 minutes). A software program was developed to map the DA testing spot (2° circle, 5° superior to the fovea) to the OCT B-scans. Two independent graders evaluated the B-scans within this testing spot, as well as the entire macula, recording the presence of several AMD-associated abnormalities. Multilevel mixed-effects models (accounting for correlated outcomes between 2 eyes) were used for analyses. The primary outcome was rod-intercept time (RIT), defined in minutes, as a continuous variable. For subjects unable to reach RIT within the 20 minutes of testing, the value of 20 was assigned. We included 137 eyes (n = 77 subjects), 72.3% (n = 99 eyes) with AMD and the remainder belonging to the comparison group. Multivariable analysis revealed that even after adjusting for age and AMD stage, the presence of any abnormalities within the DA testing spot (ß = 4.8, P < 0.001), as well as any abnormalities in the macula (ß = 2.4, P = 0.047), were significantly associated with delayed RITs and therefore impaired DA. In eyes with no structural changes within the DA testing spot (n = 76, 55.5%), the presence of any abnormalities in the remaining macula was still associated with delayed RITs (ß = 2.00, P = 0.046). Presence of subretinal drusenoid deposits and ellipsoid zone disruption were a consistent predictor of RIT, whether located within the DA testing spot (P = 0.001 for both) or anywhere in the macula (P < 0.001 for both). Within the

  19. Structures and Mechanisms Design Concepts for Adaptive Deployable Entry Placement Technology

    Science.gov (United States)

    Yount, Bryan C.; Arnold, James O.; Gage, Peter J.; Mockelman, Jeffrey; Venkatapathy, Ethiraj

    2012-01-01

    System studies have shown that large deployable aerodynamic decelerators such as the Adaptive Deployable Entry and Placement Technology (ADEPT) concept can revolutionize future robotic and human exploration missions involving atmospheric entry, descent and landing by significantly reducing the maximum heating rate, total heat load, and deceleration loads experienced by the spacecraft during entry [1-3]. ADEPT and the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) [4] share the approach of stowing the entry system in the shroud of the launch vehicle and deploying it to a much larger diameter prior to entry. The ADEPT concept provides a low ballistic coefficient for planetary entry by employing an umbrella-like deployable structure consisting of ribs, struts and a fabric cover that form an aerodynamic decelerator capable of undergoing hypersonic flight. The ADEPT "skin" is a 3-D woven carbon cloth that serves as a thermal protection system (TPS) and as a structural surface that transfers aerodynamic forces to the underlying ribs [5]. This paper focuses on design activities associated with integrating ADEPT components (cloth, ribs, struts and mechanisms) into a system that can function across all configurations and environments of a typical mission concept: stowed during launch, in-space deployment, entry, descent, parachute deployment and separation from the landing payload. The baseline structures and mechanisms were selected via trade studies conducted during the summer and fall of 2012. They are now being incorporated into the design of a ground test article (GTA) that will be fabricated in 2013. It will be used to evaluate retention of the stowed configuration in a launch environment, mechanism operation for release, deployment and locking, and static strength of the deployed decelerator. Of particular interest are the carbon cloth interfaces, underlying hot structure, (Advanced Carbon- Carbon ribs) and other structural components (nose cap, struts, and

  20. Structural adaptation of tooth enamel protein amelogenin in the presence of SDS micelles.

    Science.gov (United States)

    Chandrababu, Karthik Balakrishna; Dutta, Kaushik; Lokappa, Sowmya Bekshe; Ndao, Moise; Evans, John Spencer; Moradian-Oldak, Janet

    2014-05-01

    Amelogenin, the major extracellular matrix protein of developing tooth enamel is intrinsically disordered. Through its interaction with other proteins and mineral, amelogenin assists enamel biomineralization by controlling the formation of highly organized enamel crystal arrays. We used circular dichroism (CD), dynamic light scattering (DLS), fluorescence, and NMR spectroscopy to investigate the folding propensity of recombinant porcine amelogenin rP172 following its interaction with SDS, at levels above critical micelle concentration. The rP172-SDS complex formation was confirmed by DLS, while an increase in the structure moiety of rP172 was noted through CD and fluorescence experiments. Fluorescence quenching analyses performed on several rP172 mutants where all but one Trp was replaced by Tyr at different sequence regions confirmed that the interaction of amelogenin with SDS micelles occurs via the N-terminal region close to Trp25 where helical segments can be detected by NMR. NMR spectroscopy and structural refinement calculations using CS-Rosetta modeling confirm that the highly conserved N-terminal domain is prone to form helical structure when bound to SDS micelles. Our findings reported here reveal interactions leading to significant changes in the secondary structure of rP172 upon treatment with SDS. These interactions may reflect the physiological relevance of the flexible nature of amelogenin and its sequence specific helical propensity that might enable it to structurally adapt with charged and potential targets such as cell surface, mineral, and other proteins during enamel biomineralization. Copyright © 2013 Wiley Periodicals, Inc.

  1. Adaptive control of structural balance for complex dynamical networks based on dynamic coupling of nodes

    Science.gov (United States)

    Gao, Zilin; Wang, Yinhe; Zhang, Lili

    2018-02-01

    In the existing research results of the complex dynamical networks controlled, the controllers are mainly used to guarantee the synchronization or stabilization of the nodes’ state, and the terms coupled with connection relationships may affect the behaviors of nodes, this obviously ignores the dynamic common behavior of the connection relationships between the nodes. In fact, from the point of view of large-scale system, a complex dynamical network can be regarded to be composed of two time-varying dynamic subsystems, which can be called the nodes subsystem and the connection relationships subsystem, respectively. Similar to the synchronization or stabilization of the nodes subsystem, some characteristic phenomena can be also emerged in the connection relationships subsystem. For example, the structural balance in the social networks and the synaptic facilitation in the biological neural networks. This paper focuses on the structural balance in dynamic complex networks. Generally speaking, the state of the connection relationships subsystem is difficult to be measured accurately in practical applications, and thus it is not easy to implant the controller directly into the connection relationships subsystem. It is noted that the nodes subsystem and the relationships subsystem are mutually coupled, which implies that the state of the connection relationships subsystem can be affected by the controllable state of nodes subsystem. Inspired by this observation, by using the structural balance theory of triad, the controller with the parameter adaptive law is proposed for the nodes subsystem in this paper, which may ensure the connection relationship matrix to approximate a given structural balance matrix in the sense of the uniformly ultimately bounded (UUB). That is, the structural balance may be obtained by employing the controlling state of the nodes subsystem. Finally, the simulations are used to show the validity of the method in this paper.

  2. Structural and functional characterization of a cold adapted TPM-domain with ATPase/ADPase activity.

    Science.gov (United States)

    Cerutti, María L; Otero, Lisandro H; Smal, Clara; Pellizza, Leonardo; Goldbaum, Fernando A; Klinke, Sebastián; Aran, Martín

    2017-03-01

    The Pfam PF04536 TPM_phosphatase family is a broadly conserved family of domains found across prokaryotes, plants and invertebrates. Despite having a similar protein fold, members of this family have been implicated in diverse cellular processes and found in varied subcellular localizations. Very recently, the biochemical characterization of two evolutionary divergent TPM domains has shown that they are able to hydrolyze phosphate groups from different substrates. However, there are still incorrect functional annotations and uncertain relationships between the structure and function of this family of domains. BA41 is an uncharacterized single-pass transmembrane protein from the Antarctic psychrotolerant bacterium Bizionia argentinensis with a predicted compact extracytoplasmic TPM domain and a C-terminal cytoplasmic low complexity region. To shed light on the structural properties that enable TPM domains to adopt divergent roles, we here accomplish a comprehensive structural and functional characterization of the central TPM domain of BA41 (BA41-TPM). Contrary to its predicted function as a beta-propeller methanol dehydrogenase, light scattering and crystallographic studies showed that BA41-TPM behaves as a globular monomeric protein and adopts a conserved Rossmann fold, typically observed in other TPM domain structures. Although the crystal structure reveals the conservation of residues involved in substrate binding, no putative catalytic or intramolecular metal ions were detected. Most important, however, extensive biochemical studies demonstrated that BA41-TPM has hydrolase activity against ADP, ATP, and other di- and triphosphate nucleotides and shares properties of cold-adapted enzymes. The role of BA41 in extracellular ATP-mediated signaling pathways and its occurrence in environmental and pathogenic microorganisms is discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. A fine structure genetic analysis evaluating ecoregional adaptability of a Bos taurus breed (Hereford.

    Directory of Open Access Journals (Sweden)

    H D Blackburn

    Full Text Available Ecoregional differences contribute to genetic environmental interactions and impact animal performance. These differences may become more important under climate change scenarios. Utilizing genetic diversity within a species to address such problems has not been fully explored. In this study Hereford cattle were genotyped with 50K Bead Chip or 770K Bovine Bead Chip to test the existence of genetic structure in five U.S. ecoregions characterized by precipitation, temperature and humidity and designated: cool arid (CA, cool humid (CH, transition zone (TZ, warm arid (WA, and warm humid (WH. SNP data were analyzed in three sequential analyses. Broad genetic structure was evaluated with STRUCTURE, and ADMIXTURE software using 14,312 SNPs after passing quality control variables. The second analysis was performed using principal coordinate analysis with 66 Tag SNPs associated in the literature with various aspects of environmental stressors (e.g., heat tolerance or production (e.g., milk production. In the third analysis TreeSelect was used with the 66 SNPs to evaluate if ecoregional allelic frequencies deviated from a central frequency and by so doing are indicative of directional selection. The three analyses suggested subpopulation structures associated with ecoregions from where animals were derived. ADMIXTURE and PCA results illustrated the importance of temperature and humidity and confirm subpopulation assignments. Comparisons of allele frequencies with TreeSelect showed ecoregion differences, in particular the divergence between arid and humid regions. Patterns of genetic variability obtained by medium and high density SNP chips can be used to acclimatize a temperately derived breed to various ecoregions. As climate change becomes an important factor in cattle production, this study should be used as a proof of concept to review future breeding and conservation schemes aimed at adaptation to climatic events.

  4. Adaptive Atmospheric Modeling Key Techniques in Grid Generation, Data Structures, and Numerical Operations with Applications

    CERN Document Server

    Behrens, Jörn

    2006-01-01

    Gives an overview and guidance in the development of adaptive techniques for atmospheric modeling. This book covers paradigms of adaptive techniques, such as error estimation and adaptation criteria. Considering applications, it demonstrates several techniques for discretizing relevant conservation laws from atmospheric modeling.

  5. Structure transformations of endocrine system organs during adaptation to increased radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Ermakova, O.V. [Institute of Biology, Komi Scientific Centre, Ural Division of Russian Academy of Sciences, Syktyvkar (Russian Federation)

    2004-07-01

    It is well known that during ecological monitoring of contaminated territories registration of early abnormalities in an organism is hampered by man-caused influence of habitat. Under these circumstances study of both structural and functional changes in organs and tissues of rodents inhabiting radioactive contaminated territories is of great importance. Study of structural features of endocrine glands, hormones of which trigger the process of active adaptive changes in an organism, is very important in radioecological surveys. Basing on long-term study of voles we have determined that long-term living by rodents on the territories characterized by increased natural and artificial radioactivity (radium contaminated fields in the Komi Republic and 30-km zone of Chernobyl APS) substantially influences morpho-functional state of endocrine system organs, causing quantitative and qualitative changes. It is demonstrated that population processes modify biological consequences of small doze chronic ionizing radiation in habitat. We noticed the following: high heterogeneity of histological changes of thyroid gland and adrenal gland as a response to radioactive habitat contamination; disorder of interconnection among different links of endocrine system; dependence of radiation effects on gender, age, degree and character of radiation contamination of a habitat as well as duration of radioactive influence. We have got data on morphological characteristics of thyroid gland and adrenal gland during different phases of population amount of this kind of rodents. It was discovered that effectiveness of radiation influence is not the same during different periods of population cycle. Presence of voles on the territories characterized by increased radioactivity causes chronic tension of adrenal cortex (increasing of the organ mass, enlarging of thickness of zona fasciculata and zona reticularis). Destructive-necrotic processes combine with manifestation of reparative regeneration

  6. Different molecular and structural adaptations with eccentric and conventional strength training in elderly men and women.

    Science.gov (United States)

    Mueller, Matthias; Breil, Fabio Andreas; Lurman, Glenn; Klossner, Stephan; Flück, Martin; Billeter, Rudolf; Däpp, Christoph; Hoppeler, Hans

    2011-01-01

    Reprogramming of gene expression contributes to structural and functional adaptation of muscle tissue in response to altered use. The aim of this study was to investigate mechanisms for observed improvements in leg extension strength, gain in relative thigh muscle mass and loss of body and thigh fat content in response to eccentric and conventional strength training in elderly men (n = 14) and women (n = 14; average age of the men and women: 80.1 ± 3.7 years) by means of structural and molecular analyses. Biopsies were collected from m. vastus lateralis in the resting state before and after 12 weeks of training with two weekly resistance exercise sessions (RET) or eccentric ergometer sessions (EET). Gene expression was analyzed using custom-designed low-density PCR arrays. Muscle ultrastructure was evaluated using EM morphometry. Gain in thigh muscle mass was paralleled by an increase in muscle fiber cross-sectional area (hypertrophy) with RET but not with EET, where muscle growth is likely occurring by the addition of sarcomeres in series or by hyperplasia. The expression of transcripts encoding factors involved in muscle growth, repair and remodeling (e.g., IGF-1, HGF, MYOG, MYH3) was increased to a larger extent after EET than RET. MicroRNA 1 expression was decreased independent of the training modality, and was paralleled by an increased expression of IGF-1 representing a potential target. IGF-1 is a potent promoter of muscle growth, and its regulation by microRNA 1 may have contributed to the gain of muscle mass observed in our subjects. EET depressed genes encoding mitochondrial and metabolic transcripts. The changes of several metabolic and mitochondrial transcripts correlated significantly with changes in mitochondrial volume density. Intramyocellular lipid content was decreased after EET concomitantly with total body fat. Changes in intramyocellular lipid content correlated with changes in body fat content with both RET and EET. In the elderly, RET and

  7. Structure transformations of endocrine system organs during adaptation to increased radioactivity

    International Nuclear Information System (INIS)

    Ermakova, O.V.

    2004-01-01

    It is well known that during ecological monitoring of contaminated territories registration of early abnormalities in an organism is hampered by man-caused influence of habitat. Under these circumstances study of both structural and functional changes in organs and tissues of rodents inhabiting radioactive contaminated territories is of great importance. Study of structural features of endocrine glands, hormones of which trigger the process of active adaptive changes in an organism, is very important in radioecological surveys. Basing on long-term study of voles we have determined that long-term living by rodents on the territories characterized by increased natural and artificial radioactivity (radium contaminated fields in the Komi Republic and 30-km zone of Chernobyl APS) substantially influences morpho-functional state of endocrine system organs, causing quantitative and qualitative changes. It is demonstrated that population processes modify biological consequences of small doze chronic ionizing radiation in habitat. We noticed the following: high heterogeneity of histological changes of thyroid gland and adrenal gland as a response to radioactive habitat contamination; disorder of interconnection among different links of endocrine system; dependence of radiation effects on gender, age, degree and character of radiation contamination of a habitat as well as duration of radioactive influence. We have got data on morphological characteristics of thyroid gland and adrenal gland during different phases of population amount of this kind of rodents. It was discovered that effectiveness of radiation influence is not the same during different periods of population cycle. Presence of voles on the territories characterized by increased radioactivity causes chronic tension of adrenal cortex (increasing of the organ mass, enlarging of thickness of zona fasciculata and zona reticularis). Destructive-necrotic processes combine with manifestation of reparative regeneration

  8. Exploration of the factor structure of the Kirton Adaption-Innovation Inventory using bootstrapping estimation.

    Science.gov (United States)

    Im, Subin; Min, Soonhong

    2013-04-01

    Exploratory factor analyses of the Kirton Adaption-Innovation Inventory (KAI), which serves to measure individual cognitive styles, generally indicate three factors: sufficiency of originality, efficiency, and rule/group conformity. In contrast, a 2005 study by Im and Hu using confirmatory factor analysis supported a four-factor structure, dividing the sufficiency of originality dimension into two subdimensions, idea generation and preference for change. This study extends Im and Hu's (2005) study of a derived version of the KAI by providing additional evidence of the four-factor structure. Specifically, the authors test the robustness of the parameter estimates to the violation of normality assumptions in the sample using bootstrap methods. A bias-corrected confidence interval bootstrapping procedure conducted among a sample of 356 participants--members of the Arkansas Household Research Panel, with middle SES and average age of 55.6 yr. (SD = 13.9)--showed that the four-factor model with two subdimensions of sufficiency of originality fits the data significantly better than the three-factor model in non-normality conditions.

  9. Structural basis of evasion of cellular adaptive immunity by HIV-1 Nef

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Xiaofei; Singh, Rajendra; Homann, Stefanie; Yang, Haitao; Guatelli, John; Xiong, Yong (Yale); (VA); (UCSD)

    2012-10-24

    The HIV-1 protein Nef inhibits antigen presentation by class I major histocompatibility complex (MHC-I). We determined the mechanism of this activity by solving the crystal structure of a protein complex comprising Nef, the MHC-I cytoplasmic domain (MHC-I CD) and the {mu}1 subunit of the clathrin adaptor protein complex 1. A ternary, cooperative interaction clamps the MHC-I CD into a narrow binding groove at the Nef-{mu}1 interface, which encompasses the cargo-recognition site of {mu}1 and the proline-rich strand of Nef. The Nef C terminus induces a previously unobserved conformational change in {mu}1, whereas the N terminus binds the Nef core to position it optimally for complex formation. Positively charged patches on {mu}1 recognize acidic clusters in Nef and MHC-I. The structure shows how Nef functions as a clathrin-associated sorting protein to alter the specificity of host membrane trafficking and enable viral evasion of adaptive immunity.

  10. Unusual Lipid A from a Cold-Adapted Bacterium: Detailed Structural Characterization.

    Science.gov (United States)

    Casillo, Angela; Ziaco, Marcello; Lindner, Buko; Parrilli, Ermenegilda; Schwudke, Dominik; Holgado, Aurora; Verstrepen, Lynn; Sannino, Filomena; Beyaert, Rudi; Lanzetta, Rosa; Tutino, Maria Luisa; Corsaro, Maria Michela

    2017-09-19

    Colwellia psychrerythraea 34H is a Gram-negative cold-adapted microorganism that adopts many strategies to cope with the limitations associated with the low temperatures of its habitat. In this study, we report the complete characterization of the lipid A moiety from the lipopolysaccharide of Colwellia. Lipid A and its partially deacylated derivative were completely characterized by high-resolution mass spectrometry, NMR spectroscopy, and chemical analysis. An unusual structure with a 3-hydroxy unsaturated tetradecenoic acid as a component of the primary acylation pattern was identified. In addition, the presence of a partially acylated phosphoglycerol moiety on the secondary acylation site at the 3-position of the reducing 2-amino-2-deoxyglucopyranose unit caused tremendous natural heterogeneity in the structure of lipid A. Biological-activity assays indicated that C. psychrerythraea 34H lipid A did not show an agonistic or antagonistic effect upon testing in human macrophages. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Design Process of Flight Vehicle Structures for a Common Bulkhead and an MPCV Spacecraft Adapter

    Science.gov (United States)

    Aggarwal, Pravin; Hull, Patrick V.

    2015-01-01

    Design and manufacturing space flight vehicle structures is a skillset that has grown considerably at NASA during that last several years. Beginning with the Ares program and followed by the Space Launch System (SLS); in-house designs were produced for both the Upper Stage and the SLS Multipurpose crew vehicle (MPCV) spacecraft adapter. Specifically, critical design review (CDR) level analysis and flight production drawing were produced for the above mentioned hardware. In particular, the experience of this in-house design work led to increased manufacturing infrastructure for both Marshal Space Flight Center (MSFC) and Michoud Assembly Facility (MAF), improved skillsets in both analysis and design, and hands on experience in building and testing (MSA) full scale hardware. The hardware design and development processes from initiation to CDR and finally flight; resulted in many challenges and experiences that produced valuable lessons. This paper builds on these experiences of NASA in recent years on designing and fabricating flight hardware and examines the design/development processes used, as well as the challenges and lessons learned, i.e. from the initial design, loads estimation and mass constraints to structural optimization/affordability to release of production drawing to hardware manufacturing. While there are many documented design processes which a design engineer can follow, these unique experiences can offer insight into designing hardware in current program environments and present solutions to many of the challenges experienced by the engineering team.

  12. Biomolecular structure refinement based on adaptive restraints using local-elevation simulation

    International Nuclear Information System (INIS)

    Christen, Markus; Keller, Bettina; Gunsteren, Wilfred F. van

    2007-01-01

    Introducing experimental values as restraints into molecular dynamics (MD) simulation to bias the values of particular molecular properties, such as nuclear Overhauser effect intensities or distances, dipolar couplings, 3 J-coupling constants, chemical shifts or crystallographic structure factors, towards experimental values is a widely used structure refinement method. Because multiple torsion angle values φ correspond to the same 3 J-coupling constant and high-energy barriers are separating those, restraining 3 J-coupling constants remains difficult. A method to adaptively enforce restraints using a local elevation (LE) potential energy function is presented and applied to 3 J-coupling constant restraining in an MD simulation of hen egg-white lysozyme (HEWL). The method successfully enhances sampling of the restrained torsion angles until the 37 experimental 3 J-coupling constant values are reached, thereby also improving the agreement with the 1,630 experimental NOE atom-atom distance upper bounds. Afterwards the torsional angles φ are kept restrained by the built-up local-elevation potential energies

  13. Interactions between concentric form-from-structure and face perception revealed by visual masking but not adaptation

    Science.gov (United States)

    Feczko, Eric; Shulman, Gordon L.; Petersen, Steven E.; Pruett, John R.

    2014-01-01

    Findings from diverse subfields of vision research suggest a potential link between high-level aspects of face perception and concentric form-from-structure perception. To explore this relationship, typical adults performed two adaptation experiments and two masking experiments to test whether concentric, but not nonconcentric, Glass patterns (a type of form-from-structure stimulus) utilize a processing mechanism shared by face perception. For the adaptation experiments, subjects were presented with an adaptor for 5 or 20 s, prior to discriminating a target. In the masking experiments, subjects saw a mask, then a target, and then a second mask. Measures of discriminability and bias were derived and repeated measures analysis of variance tested for pattern-specific masking and adaptation effects. Results from Experiment 1 show no Glass pattern-specific effect of adaptation to faces; results from Experiment 2 show concentric Glass pattern masking, but not adaptation, may impair upright/inverted face discrimination; results from Experiment 3 show concentric and radial Glass pattern masking impaired subsequent upright/inverted face discrimination more than translational Glass pattern masking; and results from Experiment 4 show concentric and radial Glass pattern masking impaired subsequent face gender discrimination more than translational Glass pattern masking. Taken together, these findings demonstrate interactions between concentric form-from-structure and face processing, suggesting a possible common processing pathway. PMID:24563526

  14. Sol-gel route approach and improvisation in physico-chemical, structural, magnetic and electrical properties of BaCox/2Znx/2ZrxFe(12-2x)O19 ferrites

    Science.gov (United States)

    Kaur Jassal, Amanpreet; Mudsainiyan, R. K.; Chawla, S. K.; Anu; Bindra Narang, Sukhleen; Pubby, Kunal

    2018-02-01

    The structural and magnetic properties of Zn, Co and Zr cations doped barium hexaferrite [Ba(Znx/2Cox/2)xZrxFe(12-2x)O19] nanoparticles synthesized by sol-gel method have been investigated. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) were employed to investigate the physico-chemical properties of the obtained ferrite samples. XRD studies reveal that the magnetoplumbite structure for all sample (up to x = 0.8) have been formed and the crystallite size of nanoparticles lies in the range of 34-46 nm. At higher dopant concentration, other impurities (α-Fe2O3 and BaFe2O4 etc.) have been observed. Magnetic studies indicate that site occupancy and nature of dopant ions greatly affect the behavior of magnetic properties. The results of VSM and LCR analysis show that magnetic and electrical parameters vary with an increase in dopant concentration. The results of BET surface area of samples indicate that these types of materials could be used for catalytic properties. Dielectric constant, dielectric loss tangent and A.C. conductivity weremeasured using impedance analyzer over wide frequency range 20 Hz-120 MHz. All the three parameters increase significantly with increase in doping. Increase in dielectric constant proposes these materials for fabrication of microwave devices, while increase in dielectric loss tangent proposes these for applications such as attenuator, absorber etc.

  15. Micro-ion beam analysis of physico-chemical reactions in vitro induced by nano-structured sol-gel derived bioactive glasses

    International Nuclear Information System (INIS)

    Lao, J.

    2007-07-01

    The study of bioactive glasses is a multi-field area of research aiming at a major goal: the development of new generation biomaterials that would be able to bond with host tissues through the formation of a strong interfacial bond, together with helping the body heal itself through the stimulation of specific cellular responses. Thus clinical applications of bioactive glasses mainly concern dental surgery and orthopedics, for filling osseous defects. For this purpose, we have elaborated bioactive glasses in the binary SiO 2 -CaO system, ternary SiO 2 -CaO-P 2 O 5 system, and for the first time, to our knowledge, strontium-doped SiO 2 -CaO-SrO and SiO 2 -CaO-P 2 O 5 -SrO glasses. The materials were elaborated using the sol-gel process, which allowed the synthesis of nano-porous materials with great purity and homogeneity. The bio-activity of the glasses was clearly demonstrated in vitro: in contact with biological fluids, the whole lot of mate-rials were able to induce the formation of a Ca-P-Mg layer a few microns thick at their surface. Our work is characterized by the use of PIXE-RBS nuclear microprobes to study the bioactive glass/biological fluids interface. Thanks to these methods we obtained chemical maps that made possible the analysis of major and trace elements concentrations at the interface. Moreover, quantitative information regarding the local reactivity of glasses were acquired. These data are important to evaluate the kinetics and amplitude of the physico-chemical reactions involved in the bio-activity process. Thus, we highlighted that the binary glass is the highest reactive regarding the dissolution of the glassy matrix as well as the first appearance of the Ca-P rich layer. However the Ca/P atomic ratio calculated at the glass/biological fluids interface decreases slowly, indicating that the Ca-P-Mg layer encounters difficulties to be changed into a more stable apatitic phase. For the P-containing glasses, the de-alkalinization of the matrix and

  16. Structural insights into the adaptation of proliferating cell nuclear antigen (PCNA) from Haloferax volcanii to a high-salt environment

    OpenAIRE

    Morgunova, Ekaterina; Gray, Fiona C.; MacNeill, Stuart A.; Ladenstein, Rudolf

    2009-01-01

    The crystal structure of PCNA from the halophilic archaeon H. volcanii reveals specific features of the charge distribution on the protein surface that reflect adaptation to a high-salt environment and suggests a different type of interaction with DNA in halophilic PCNAs.

  17. A three-photon microscope with adaptive optics for deep-tissue in vivo structural and functional brain imaging

    Science.gov (United States)

    Tao, Xiaodong; Lu, Ju; Lam, Tuwin; Rodriguez, Ramiro; Zuo, Yi; Kubby, Joel

    2017-02-01

    We developed a three-photon adaptive optics add-on to a commercial two-photon laser scanning microscope. We demonstrated its capability for structural and functional imaging of neurons labeled with genetically encoded red fluorescent proteins or calcium indicators deep in the living mouse brain with cellular and subcellular resolution.

  18. Cultural Differences and User Instructions: Effects of a Culturally Adapted Manual Structure on Western and Chinese Users

    NARCIS (Netherlands)

    Li, Qian; de Jong, Menno D.T.; Karreman, Joyce

    2015-01-01

    Purpose: Research shows that Western and Chinese technical communicators structure their documents in different ways. The research reported in this article is a first attempt to systematically explore the effects cultural adaptations of user instructions have on users. Specifically, we investigate

  19. Adaptation of quantum chemistry software for the electronic structure calculations on GPU for solid-state systems

    International Nuclear Information System (INIS)

    Gusakov, V.E.; Bel'ko, V.I.; Dorozhkin, N.N.

    2015-01-01

    We report on adaptation of quantum chemistry software - Quantum Espresso and LASTO - for the electronic structure calculations for the complex solid-state systems on the GeForce series GPUs using the nVIDIA CUDA technology. Specifically, protective covering based on transition metal nitrides are considered. (authors)

  20. Using Structural Equation Modeling to Validate Online Game Players' Motivations Relative to Self-Concept and Life Adaptation

    Science.gov (United States)

    Yang, Shu Ching; Huang, Chiao Ling

    2013-01-01

    This study aimed to validate a systematic instrument to measure online players' motivations for playing online games (MPOG) and examine how the interplay of differential motivations impacts young gamers' self-concept and life adaptation. Confirmatory factor analysis determined that a hierarchical model with a two-factor structure of…

  1. Long-Term Structural and Functional Myocardial Adaptations in Healthy Living Kidney Donors: A Pilot Study.

    Directory of Open Access Journals (Sweden)

    Diego Bellavia

    Full Text Available Compensatory renal hypertrophy following unilateral nephrectomy (UNX occurs in the remaining kidney. However, the long-term cardiac adaptive process to UNX remains poorly defined in humans. Our goal was to characterize myocardial structure and function in living kidney donors (LKDs, approximately 12 years after UNX.Cardiac function and structure in 15 Italian LKDs, at least 5 years after UNX (median time from donation = 8.4 years was investigated and compared to those of age and sex matched U.S. citizens healthy controls (n = 15. Standard and speckle tracking echocardiography (STE was performed in both LKDs and controls. Plasma angiotensin II, aldosterone, atrial natriuretic peptide (ANP, N terminus pro B-type natriuretic peptide (NT-proBNP, cyclic guanylyl monophosphate (cGMP, and amino-terminal peptide of procollagen III (PIIINP were also collected. Median follow-up was 11.9 years. In LKDs, LV geometry and function by STE were similar to controls, wall thickness and volumes were within normal limits also by CMR. In LKDs, CMR was negative for myocardial fibrosis, but apical rotation and LV torsion obtained by STE were impaired as compared to controls (21.4 ± 7.8 vs 32.7 ± 8.9 degrees, p = 0.04. Serum creatinine and PIIINP levels were increased [1.1 (0.9-1.3 mg/dL, and 5.8 (5.4-7.6] μg/L, respectively, while urinary cGMP was reduced [270 (250-355 vs 581 (437-698 pmol/mL] in LKDs. No LKD developed cardiovascular or renal events during follow-up.Long-term kidney donors have no apparent structural myocardial abnormalities as assessed by contrast enhanced CMR. However, myocardial deformation of the apical segments, as well as apical rotation, and LV torsion are reduced. The concomitant increase in circulating PIIINP level is suggestive of fibrosis. Further studies, focused on US and EU patients are warranted to evaluate whether these early functional modifications will progress to a more compromised cardiac function and structure at a later time.

  2. Sapc - Application for Adapting Scanned Analogue Photographs to Use Them in Structure from Motion Technology

    Science.gov (United States)

    Salach, A.

    2017-05-01

    The documentary value of analogue scanned photographs is invaluable. A large and rich collection of archival photographs is often the only source of information about past of the selected area. This paper presents a method of adaptation of scanned, analogue photographs to suitable form allowing to use them in Structure from Motion technology. For this purpose, an automatic algorithm, implemented in the application called SAPC (Scanned Aerial Photographs Correction), which transforms scans to a form, which characteristic similar to the images captured by a digital camera, was invented. Images, which are created in the applied program as output data, are characterized by the same principal point position in each photo and the same resolution through cutting out the black photo frame. Additionally, SAPC generates a binary image file, which can mask areas of fiducial marks. In the experimental section, scanned, analogue photographs of Warsaw, which had been captured in 1986, were used in two variants: unprocessed and processed in SAPC application. An insightful analysis was conducted on the influence of transformation in SAPC on quality of spatial orientation of photographs. Block adjustment through aerial triangulation was calculated using two SfM software products: Agisoft PhotoScan and Pix4d and their results were compared with results obtained from professional photogrammetric software - Trimble Inpho. The author concluded that pre-processing in SAPC application had a positive impact on a quality of block orientation of scanned, analogue photographs, using SfM technology.

  3. A memory structure adapted simulated annealing algorithm for a green vehicle routing problem.

    Science.gov (United States)

    Küçükoğlu, İlker; Ene, Seval; Aksoy, Aslı; Öztürk, Nursel

    2015-03-01

    Currently, reduction of carbon dioxide (CO2) emissions and fuel consumption has become a critical environmental problem and has attracted the attention of both academia and the industrial sector. Government regulations and customer demands are making environmental responsibility an increasingly important factor in overall supply chain operations. Within these operations, transportation has the most hazardous effects on the environment, i.e., CO2 emissions, fuel consumption, noise and toxic effects on the ecosystem. This study aims to construct vehicle routes with time windows that minimize the total fuel consumption and CO2 emissions. The green vehicle routing problem with time windows (G-VRPTW) is formulated using a mixed integer linear programming model. A memory structure adapted simulated annealing (MSA-SA) meta-heuristic algorithm is constructed due to the high complexity of the proposed problem and long solution times for practical applications. The proposed models are integrated with a fuel consumption and CO2 emissions calculation algorithm that considers the vehicle technical specifications, vehicle load, and transportation distance in a green supply chain environment. The proposed models are validated using well-known instances with different numbers of customers. The computational results indicate that the MSA-SA heuristic is capable of obtaining good G-VRPTW solutions within a reasonable amount of time by providing reductions in fuel consumption and CO2 emissions.

  4. SAPC – APPLICATION FOR ADAPTING SCANNED ANALOGUE PHOTOGRAPHS TO USE THEM IN STRUCTURE FROM MOTION TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    A. Salach

    2017-05-01

    Full Text Available The documentary value of analogue scanned photographs is invaluable. A large and rich collection of archival photographs is often the only source of information about past of the selected area. This paper presents a method of adaptation of scanned, analogue photographs to suitable form allowing to use them in Structure from Motion technology. For this purpose, an automatic algorithm, implemented in the application called SAPC (Scanned Aerial Photographs Correction, which transforms scans to a form, which characteristic similar to the images captured by a digital camera, was invented. Images, which are created in the applied program as output data, are characterized by the same principal point position in each photo and the same resolution through cutting out the black photo frame. Additionally, SAPC generates a binary image file, which can mask areas of fiducial marks. In the experimental section, scanned, analogue photographs of Warsaw, which had been captured in 1986, were used in two variants: unprocessed and processed in SAPC application. An insightful analysis was conducted on the influence of transformation in SAPC on quality of spatial orientation of photographs. Block adjustment through aerial triangulation was calculated using two SfM software products: Agisoft PhotoScan and Pix4d and their results were compared with results obtained from professional photogrammetric software – Trimble Inpho. The author concluded that pre-processing in SAPC application had a positive impact on a quality of block orientation of scanned, analogue photographs, using SfM technology.

  5. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea

    KAUST Repository

    Takahashi, Masateru

    2018-01-24

    The deep-sea brines of the Red Sea are remote and unexplored environments characterized by high temperatures, anoxic water, and elevated concentrations of salt and heavy metals. This environment provides a rare system to study the interplay between halophilic and thermophilic adaptation in biologic macromolecules. The present article reports the first DNA polymerase with halophilic and thermophilic features. Biochemical and structural analysis by Raman and circular dichroism spectroscopy showed that the charge distribution on the protein’s surface mediates the structural balance between stability for thermal adaptation and flexibility for counteracting the salt-induced rigid and nonfunctional hydrophobic packing. Salt bridge interactions via increased negative and positive charges contribute to structural stability. Salt tolerance, conversely, is mediated by a dynamic structure that becomes more fixed and functional with increasing salt concentration. We propose that repulsive forces among excess negative charges, in addition to a high percentage of negatively charged random coils, mediate this structural dynamism. This knowledge enabled us to engineer a halophilic version of KOD DNA polymerase.—Takahashi, M., Takahashi, E., Joudeh, L. I., Marini, M., Das, G., Elshenawy, M. M., Akal, A., Sakashita, K., Alam, I., Tehseen, M., Sobhy, M. A., Stingl, U., Merzaban, J. S., Di Fabrizio, E., Hamdan, S. M. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea.

  6. Broad scale agreement between intertidal habitats and adaptive traits on a basis of contrasting population genetic structure

    Science.gov (United States)

    Zardi, G. I.; Nicastro, K. R.; Ferreira Costa, J.; Serrão, E. A.; Pearson, G. A.

    2013-10-01

    Understanding the extent to which neutral processes and adaptive divergence shape the spatial structure of natural populations is a major goal in evolutionary biology and is especially important for the identification of significant levels of biodiversity. Our results identified replicated habitat-specific (adaptive) phenotypic divergence in the brown macroalga Fucus vesiculosus that is independent of population (neutral) genetic structure. F. vesiculosus inhabits contiguous and contrasting marine to estuarine intertidal habitats. Combining analyses of genetic and phenotypic traits of populations living under differential selective regimes (estuaries and open coast), we investigated levels of neutral genetic differentiation and adaptive physiological responses to emersion stress. In southwest England (SW UK) and northern Iberia (N. Iberia), populations living in estuaries and marine coastal habitats were genetically characterized at six microsatellite loci. In N. Iberia, two clades with limited admixture were recovered, each including one open coast site and the adjacent estuarine location. In contrast, SW UK samples clustered according to habitat and formed three distinct groups of genotypes; one including the two open coast locations and the other two representing each of the estuarine sites. Temperature loggers revealed distinct emersion regimes that characterized each habitat type independently of the region, while water and air temperature profiles showed site-specific trends. Despite acclimation under usual conditions, trait means of emersion stress resilience showed a strong phenotypic divergence between habitats, consistent with environmental clines in exposure time observed in the different habitats. We demonstrate that neutral genetic clusters do not reflect locally adapted population units. Our results identified replicated habitat-specific (adaptive) phenotypic divergence that is independent of population (neutral) genetic structure in F. vesiculosus

  7. Fused heterocycles bearing bridgehead nitrogen as potent HIV-1 NNRTIs. Part 3: optimization of [1,2,4]triazolo[1,5-a]pyrimidine core via structure-based and physicochemical property-driven approaches.

    Science.gov (United States)

    Huang, Boshi; Li, Cuicui; Chen, Wenmin; Liu, Tao; Yu, Mingyan; Fu, Lu; Sun, Yueyue; Liu, Huiqing; De Clercq, Erik; Pannecouque, Christophe; Balzarini, Jan; Zhan, Peng; Liu, Xinyong

    2015-03-06

    In our arduous efforts to develop new potent HIV-1 non-nucleoside reverse transcriptase (RT) inhibitors (NNRTIs), novel piperidine-linked [1,2,4]triazolo[1,5-a]pyrimidine derivatives were designed, synthesized and evaluated for their antiviral activities in MT-4 cell cultures. Biological results showed that all of the title compounds displayed moderate to excellent activities against wild-type (wt) HIV-1 strain (IIIB) with EC50 values ranging from 8.1 nM to 2284 nM in a cell-based assay. Among them, the most promising analog 7d possessed an EC50 value of 8.1 nM against wt HIV-1, which was much more potent than the reference drugs DDI, 3 TC, NVP and DLV. Additionally, 7d demonstrated weak activity against the double mutant HIV-1 strain (K103N + Y181C), and was more efficient than NVP in a RT inhibition assay. Besides, some measured and calculated physicochemical properties of 7d, like log P and water solubility, as well as the structure-activity relationships (SARs) analysis have been discussed in detail. Furthermore, the binding mode of the active compound 7d was rationalized by molecular simulation studies. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  8. Adaptive/learning control of large space structures - System identification techniques. [for multi-configuration flexible spacecraft

    Science.gov (United States)

    Thau, F. E.; Montgomery, R. C.

    1980-01-01

    Techniques developed for the control of aircraft under changing operating conditions are used to develop a learning control system structure for a multi-configuration, flexible space vehicle. A configuration identification subsystem that is to be used with a learning algorithm and a memory and control process subsystem is developed. Adaptive gain adjustments can be achieved by this learning approach without prestoring of large blocks of parameter data and without dither signal inputs which will be suppressed during operations for which they are not compatible. The Space Shuttle Solar Electric Propulsion (SEP) experiment is used as a sample problem for the testing of adaptive/learning control system algorithms.

  9. Synthesis and physicochemical characterization of two lead(II) complexes with O-, N-donor ligands. Lone pair functionality and crystal structure

    Science.gov (United States)

    Masternak, Joanna; Barszcz, Barbara; Hodorowicz, Maciej; Khavryuchenko, Oleksiy V.; Majka, Alina

    2015-02-01

    A dinuclear [Pb2(4-CHO-5-MeIm)6(NO3)2](NO3)2 (1) and a polynuclear [Pb(2-pzc)2(H2O)]n (2) complexes (where 5(4)-carbaldehyde-4(5)-methylimidazole (5(4)-CHO-4(5)-MeIm) and pyrazine-2-carboxylic acid (2-pzcH)) have been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. Structural determination for complex 1 reveals a cationic species [Pb(4-CHO-5-MeIm)3]2+ connected through bridging nitrate(V) ions. There are also an uncoordinated nitrate ions as counterions. Complex 2 is a three-dimensional architecture consisting of Pb6O12 building units. The pyrazine-2-carboxylato ligand behaves as a chelating agent and a bi-connective bridge. The coordination polyhedra around lead(II) ion could be described as a distorted docecahedron (1) or monocapped trigonal prism (2). The luminescent properties of 1 and 2 investigated in the solid state at room temperature indicate structure-dependent photoluminescent properties. The DFT calculations and the X-ray structural data point on rather hemidirected type of coordination around Pb(II) ions of 1 and 2.

  10. Structural confirmation, single X-ray crystallographic behavior, molecular docking and other physico-chemical properties of gerberinol, a natural dimethyl dicoumarol from Gerbera lanuginosa Benth. (Compositae)

    Science.gov (United States)

    Brahmachari, Goutam; Das, Saktipada; Kumar, Abhishek; Misra, Neeraj; Sharma, Sakshi; Gupta, Vivek K.

    2017-05-01

    The proposed structure of gerberinol (1), a naturally occurring dimethyl dicoumarol, has been conclusively established on the basis of its detailed spectral and single crystal X-ray analyses. The compound, C21H16O6, crystallizes in the monoclinic space group P21/c with the following unit-cell parameters: a = 14.0884(14), b = 15.1746(15), c = 7.6392(8)Å, α = 90.00°, β = 98.949(4)°, γ = 90.00° and Z = 4. The crystal structure was solved by direct methods using single-crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R-value of 11.43 for 2377 observed reflections. Exhaustive theoretical studies on the molecular structure, vibrational spectra, HOMO, LUMO, MESP surfaces, and molecular docking of this plant-derived natural molecule have also been performed. The equilibrium geometry of the title compound has been obtained and analyzed using DFT-B3LYP/6-311 + G(d,p) method. Molecular docking study of the molecule for predicting its possible biological activities revealed that the compound might be a potent antimicrobial, neurodegenerative and anticancer agent as evidenced from its excellent FF (full fitness) score for 1FUJ and 1ZX1 enzymes.

  11. Ultrastructural and biochemical characterization of mechanically adaptable collagenous structures in the edible sea urchin Paracentrotus lividus.

    Science.gov (United States)

    Barbaglio, Alice; Tricarico, Serena; Ribeiro, Ana R; Di Benedetto, Cristiano; Barbato, Marta; Dessì, Desirèe; Fugnanesi, Valeria; Magni, Stefano; Mosca, Fabio; Sugni, Michela; Bonasoro, Francesco; Barbosa, Mario A; Wilkie, Iain C; Candia Carnevali, M Daniela

    2015-06-01

    The viscoelastic properties of vertebrate connective tissues rarely undergo significant changes within physiological timescales, the only major exception being the reversible destiffening of the mammalian uterine cervix at the end of pregnancy. In contrast to this, the connective tissues of echinoderms (sea urchins, starfish, sea cucumbers, etc.) can switch reversibly between stiff and compliant conditions in timescales of around a second to minutes. Elucidation of the molecular mechanism underlying such mutability has implications for the zoological, ecological and evolutionary field. Important information could also arise for veterinary and biomedical sciences, particularly regarding the pathological plasticization or stiffening of connective tissue structures. In the present investigation we analyzed aspects of the ultrastructure and biochemistry in two representative models, the compass depressor ligament and the peristomial membrane of the edible sea urchin Paracentrotus lividus, compared in three different mechanical states. The results provide further evidence that the mechanical adaptability of echinoderm connective tissues does not necessarily imply changes in the collagen fibrils themselves. The higher glycosaminoglycan (GAG) content registered in the peristomial membrane with respect to the compass depressor ligament suggests a diverse role of these molecules in the two mutable collagenous tissues. The possible involvement of GAG in the mutability phenomenon will need further clarification. During the shift from a compliant to a standard condition, significant changes in GAG content were detected only in the compass depressor ligament. Similarities in terms of ultrastructure (collagen fibrillar assembling) and biochemistry (two alpha chains) were found between the two models and mammalian collagen. Nevertheless, differences in collagen immunoreactivity, alpha chain migration on SDS-PAGE and BLAST alignment highlighted the uniqueness of sea urchin

  12. Exploring a physico-chemical multi-array explanatory model with a new multiple covariance-based technique: structural equation exploratory regression.

    Science.gov (United States)

    Bry, X; Verron, T; Cazes, P

    2009-05-29

    In this work, we consider chemical and physical variable groups describing a common set of observations (cigarettes). One of the groups, minor smoke compounds (minSC), is assumed to depend on the others (minSC predictors). PLS regression (PLSR) of m inSC on the set of all predictors appears not to lead to a satisfactory analytic model, because it does not take into account the expert's knowledge. PLS path modeling (PLSPM) does not use the multidimensional structure of predictor groups. Indeed, the expert needs to separate the influence of several pre-designed predictor groups on minSC, in order to see what dimensions this influence involves. To meet these needs, we consider a multi-group component-regression model, and propose a method to extract from each group several strong uncorrelated components that fit the model. Estimation is based on a global multiple covariance criterion, used in combination with an appropriate nesting approach. Compared to PLSR and PLSPM, the structural equation exploratory regression (SEER) we propose fully uses predictor group complementarity, both conceptually and statistically, to predict the dependent group.

  13. Hydrothermal synthesis, structural and physico-chemical characterizations of two Nasicon phosphates: M0.50IITi2(PO4)3 (M = Mn, Co)

    International Nuclear Information System (INIS)

    Essehli, Rachid; Bali, Brahim El; Benmokhtar, S.; Fejfarova, Karla; Dusek, Michal

    2009-01-01

    The family of titanium Nasicon-phosphates of generic formula M 0.5 II Ti 2 (PO 4 ) 3 has been revisited using hydrothermal techniques. Two phases have been synthesized: Mn 0.5 II Ti 2 (PO 4 ) 3 (MnTiP) and Co 0.5 II Ti 2 (PO 4 ) 3 (CoTiP). Single crystal diffraction studies show that they exhibit two different structural types. Mn 0.5 II Ti 2 (PO 4 ) 3 phosphate crystallizes in the R-3 space group, with the cell parameters a = 8.51300(10) A and c = 21.0083(3) A (V = 1318.52(3) A 3 and Z = 6). The Co 0.5 II Ti 2 (PO 4 ) 3 phosphate crystallizes in the R-3c space group, with a = 8.4608(9) A and c = 21.174(2) A (V = 1312.7(2) A 3 and Z = 6). These two compounds are clearly related to the parent Nasicon-type rhombohedral structure, which can be described using [Ti 2 (PO 4 ) 3 ] framework composed of two [TiO 6 ] octahedral interlinked via three [PO 4 ] tetrahedra. 31 P magic-angle spinning nuclear magnetic resonance (MAS-NMR) data are presented as supporting data. Curie-Weiss-type behavior is observed in the magnetic susceptibility. The phases are also characterized by IR spectroscopy and UV-visible.

  14. Structural and Functional Adaptation of Vancomycin Resistance VanT Serine Racemases.

    Science.gov (United States)

    Meziane-Cherif, Djalal; Stogios, Peter J; Evdokimova, Elena; Egorova, Olga; Savchenko, Alexei; Courvalin, Patrice

    2015-08-11

    Vancomycin resistance in Gram-positive bacteria results from the replacement of the D-alanyl-D-alanine target of peptidoglycan precursors with D-alanyl-D-lactate or D-alanyl-D-serine (D-Ala-D-Ser), to which vancomycin has low binding affinity. VanT is one of the proteins required for the production of D-Ala-D-Ser-terminating precursors by converting L-Ser to D-Ser. VanT is composed of two domains, an N-terminal membrane-bound domain, likely involved in L-Ser uptake, and a C-terminal cytoplasmic catalytic domain which is related to bacterial alanine racemases. To gain insight into the molecular function of VanT, the crystal structure of the catalytic domain of VanTG from VanG-type resistant Enterococcus faecalis BM4518 was determined. The structure showed significant similarity to type III pyridoxal 5'-phosphate (PLP)-dependent alanine racemases, which are essential for peptidoglycan synthesis. Comparative structural analysis between VanTG and alanine racemases as well as site-directed mutagenesis identified three specific active site positions centered around Asn696 which are responsible for the L-amino acid specificity. This analysis also suggested that VanT racemases evolved from regular alanine racemases by acquiring additional selectivity toward serine while preserving that for alanine. The 4-fold-lower relative catalytic efficiency of VanTG against L-Ser versus L-Ala implied that this enzyme relies on its membrane-bound domain for L-Ser transport to increase the overall rate of d-Ser production. These findings illustrate how vancomycin pressure selected for molecular adaptation of a housekeeping enzyme to a bifunctional enzyme to allow for peptidoglycan remodeling, a strategy increasingly observed in antibiotic-resistant bacteria. Vancomycin is one of the drugs of last resort against Gram-positive antibiotic-resistant pathogens. However, bacteria have evolved a sophisticated mechanism which remodels the drug target, the D-alanine ending precursors in cell wall

  15. Computational and experimental studies of microvascular void features for passive-adaptation of structural panel dynamic properties

    Science.gov (United States)

    Sears, Nicholas C.; Harne, Ryan L.

    2018-01-01

    The performance, integrity, and safety of built-up structural systems are critical to their effective employment in diverse engineering applications. In conflict with these goals, harmonic or random excitations of structural panels may promote large amplitude oscillations that are particularly harmful when excitation energies are concentrated around natural frequencies. This contributes to fatigue concerns, performance degradation, and failure. While studies have considered active or passive damping treatments that adapt material characteristics and configurations for structural control, it remains to be understood how vibration properties of structural panels may be tailored via internal material transitions. Motivated to fill this knowledge gap, this research explores an idea of adapting the static and dynamic material distribution of panels through embedded microvascular channels and strategically placed voids that permit the internal movement of fluids within the panels for structural dynamic control. Finite element model and experimental investigations probe how redistributing material in the form of microscale voids influences the global vibration modes and natural frequencies of structural panels. Through parameter studies, the relationships among void shape, number, size, and location are quantified towards their contribution to the changing structural dynamics. For the panel composition and boundary conditions considered in this report, the findings reveal that transferring material between strategically placed voids may result in eigenfrequency changes as great as 10.0, 5.0, and 7.4% for the first, second, and third modes, respectively.

  16. Application of Structured Decision Making to an Assessment of Climate Change Vulnerabilities and Adaptation Options for Sustainable Forest Management

    Directory of Open Access Journals (Sweden)

    Aynslie E. Ogden

    2009-06-01

    Full Text Available A logical starting point for climate change adaptation in the forest sector is to proactively identify management practices and policies that have a higher likelihood of achieving management objectives across a wide range of potential climate futures. This should be followed by implementation of these options and monitoring their success in achieving management objectives within an adaptive management context. Here, we implement an approach to identify locally appropriate adaptation options by tapping into the experiential knowledge base of local forest practitioners while at the same time, building capacity within this community to implement the results. We engaged 30 forest practitioners who are involved with the implementation of a regional forest management plan in identifying climate change vulnerabilities and evaluating alternative adaptation options. A structured decision-making approach was used to frame the assessment. Practitioners identified 24 adaptation options that they considered important to implement in order to achieve the regional goals and objectives of sustainable forest management in light of climate change.

  17. The uranium valence in the Cs-U-O system: crystal structures and thin layers contribution to the physico-chemical study of grain boundaries in irradiated fuel

    International Nuclear Information System (INIS)

    Van Den Berghe, S.

    2002-01-01

    The document is an abstract of a PhD thesis. The PhD thesis investigates the way in which cesium, through its effect on oxygen, modifies the uranium environment and in consequence the valence state of the uranium atom itself. To this end, the crystallographic structure and local uranium environment of several uranium uranates has been determined by Rietveld refinement of neutron and X-ray diffraction data. Thin layers of stoichiometric uranium dioxide were prepared using sputter deposition techniques and used to model interactions on the grain boundaries. They were covered with cesium and exposed to controlled amounts of oxygen, while the uranium valence state was monitored with Ultraviolet Photoelectron Spectroscopy and XPS

  18. Ambiguous Adaptation

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Lyngsie, Jacob

    We investigate why some exchange relationships terminate prematurely. We argue that investments in informal governance structures induce premature termination in relationships already governed by formal contracts. The formalized adaptive behavior of formal governance structures and the flexible...... and reciprocal adaptation of informal governance structure create ambiguity in situations of contingencies, which, subsequently, increases the likelihood of premature relationship termination. Using a large sample of exchange relationships in the global service provider industry, we find support for a hypothesis...

  19. Preliminary Phytochemical and Physicochemical Characterization of ...

    African Journals Online (AJOL)

    Purpose: To carry out phytochemical and physicochemical studies on the leaves of Gynura segetum. Methods: Preliminary phytochemical and physicochemical studies using chromatographic techniques,were carried out, Parameters evaluated include ash value, loss on drying and extractive value, amongst others.

  20. Crystal structure, Hirshfeld surfaces computational study and physicochemical characterization of the hybrid material (C7H10N)2[SnCl6]·H2O

    Science.gov (United States)

    BelhajSalah, S.; Abdelbaky, Mohammed S. M.; García-Granda, Santiago; Essalah, K.; Ben Nasr, C.; Mrad, M. L.

    2018-01-01

    A novel hybrid compound, bis(4-methylanilinium)hexachlorostannate(IV) monohydrate, formulated as (C7H10N)2[SnCl6]·H2O, has been prepared and characterized by powder and single crystal X-ray diffraction (XRD), Hirshfeld surface analysis, infrared spectroscopy (IR), optical study, differential thermal analysis(DTA) and X-ray photoelectron spectroscopy analysis (XPS). The title compound crystallizes in the monoclinic space group P21/c with a = 13.093(1)Å, b = 7.093(6)Å, c = 24.152(2)Å, β = 98.536(4)⁰ and V = 2218.4(4) Å3. Their crystal structure exhibits alternating inorganic layers parallel to the (ab) plane at z = n/2. The different entities, [SnCl6]2-, organic cations and water molecules, are connected via hydrogen bonds to form a three-dimensional network. The powder XRD data confirms the phase purity of the crystalline sample. The intermolecular interactions were investigated by Hirshfeld surfaces. The vibrational absorption bands were identified by IR spectroscopy and have been discussed. The optical properties of the crystal were studied by using optical absorption, UV-visible absorption and photoluminescence spectroscopy studies. The compound was also characterized by DTA to determine its thermal behavior with respect to the temperature. Finally, XPS technique is reported for analyzing the surface chemistry of this compound.

  1. Based on ground station adaptive optics for laser communications demonstration platform structures

    Science.gov (United States)

    Zhang, Lei; Tong, Shoufeng; Wang, Haozeng; Yang, Hongkun

    2013-08-01

    With the rapid development of modern science and technology in astronomical imaging, optical communications, optical radar, optical information processing, high-precision ranging, tracking, guidance, and remote sensing, light waves propagating in the medium, especially in the turbulent atmosphere spread more and more important. Atmospheric turbulence is one of the main factors which have influence on the performance of a laser communication system. Adaptive optics technology is an important means to solve the problem of atmospheric turbulence. This paper states how adaptive optics technique can be used in space laser communication system to compensate atmospheric turbulence when laser beam transmission through it. The core content of adaptive optics is correct laser beam wave-front disturbance in real-time,with it to enhance optical system imaging quality and the next aim is reach the level of diffraction limitation. Adaptive optics system consists of wave-front detection, wave-front control and wave-front correction . The demo platform including: atmospheric turbulence simulation unit、adaptive correction unit、signal transmitting and receiving unit. Liquid crystal spatial light modulator applications in adaptive optics system and the turbulence simulation system introduced. And used zernike polynomials method to produce atmospheric turbulence phase screen simulation analysis. Simulation results show that: in the low spatial frequency components, the atmospheric turbulence phase screen generated by Zernike polynomial method consistent with the theoretical values, but in the high spatial frequency components, the simulation results with large difference between the theoretical values. In addition, the simulation results also show that: we can change the distribution of turbulence in the atmospheric turbulence phase screen by increasing the Zernike polynomials of orders or change the receiving apertures, but to calculate the large calculate the complex and

  2. Harnessing Aquatic Physicochemical Parameters Influencing ...

    African Journals Online (AJOL)

    The management-oriented background for harnessing aquatic physicochemical parameters influencing macro invertebrate fauna of Anambra River basin for sustainable fish productivity was studied. The intra seasonal variability in the water quality of the river revealed mean transparency of 1.79 cm, Conductivity of 28.81 ...

  3. Synthesis, physicochemical characterization, and functional ...

    African Journals Online (AJOL)

    subjected to modification by acetylation. The acetylated acha starch with degree of modification 0.78 had reduced foaming capacity and amylose contents. The starches have similar organoleptic properties ranging from white, gritty, non sticky to bland tastes. Physicochemical indices investigated such as true density, bulk ...

  4. Physico-chemical wastewater treatment

    NARCIS (Netherlands)

    Mels, A.R.; Teerikangas, E.

    2002-01-01

    Wastewater reclamation strategies aimed at closing industrial water cycles and recovery of valuable components will in most cases require a combination of wastewater treatment unit operations. Biological unit operations are commonly applied as the core treatment. In addition, physico-chemical unit

  5. Structure, physicochemical and biological properties of an aqua (2,2{sup '},2''-nitrilotriacetato)-oxidovanadium(IV) salt with 4-methylpyridinium cation

    Energy Technology Data Exchange (ETDEWEB)

    Tesmar, Aleksandra; Wyrzykowski, Dariusz; Drzezdzon, Joanna; Jacewicz, Dagmara; Chmurzynski, Lech [Faculty of Chemistry, University of Gdansk (Poland); Kazimierczuk, Katarzyna [Department of Inorganic Chemistry, Gdansk University of Technology (Poland); Klak, Julia [Faculty of Chemistry, Wroclaw University (Poland); Kowalski, Szymon; Inkielewicz-Stepniak, Iwona [Department of Medical Chemistry, Medical University of Gdansk (Poland)

    2017-04-04

    The crystal structure of a nitrilotriacetate (nta) oxidovanadium(IV) salt with 4-methylpyridinium cation, [4-Me(Py)H]{sup +}, of [4-Me(Py)H][VO(nta)(H{sub 2}O)] stoichiometry was determined. The complex comprises a discrete mononuclear [VO(nta)(H{sub 2}O)]{sup -} coordination entity that can be rarely found among other known compounds containing nitrilotriacetate oxidovanadium(IV) moieties. The complex was characterized by spectroscopic (IR and EPR) methods, magnetic measurements, and thermogravimetry (TG-FTIR). The stability of the title compound in aqueous solutions was investigated by using the potentiometric titration method. Furthermore, spectrophotometric (UV/Vis) studies have revealed that the compound is capable to scavenge the superoxide free radicals (O{sub 2} {sup circle} {sup -}) as well as stable organic radicals i.e. 2,2'-azinobis(3-ethylbenzothiazoline-6 sulfonic acid) cation radical (ABTS{sup +} {sup circle}) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH {sup circle}). Finally, biological properties of the complex studied were investigated in relation to its cytoprotective activity against the oxidative damage generated exogenously by using hydrogen peroxide in the HT22 hippocampal neuronal cell line (the MTT assay). Additionally, the biological action of the compound towards two human osteosarcoma HOS and MG-63 cell lines (the MTT and BrdU tests) as well as the untransformed human osteoblast hFOB 1.19 cell line was tested. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Enhanced oxygen vacancy diffusion in Ta2O5 resistive memory devices due to infinitely adaptive crystal structure

    Science.gov (United States)

    Jiang, Hao; Stewart, Derek A.

    2016-04-01

    Metal oxide resistive memory devices based on Ta2O5 have demonstrated high switching speed, long endurance, and low set voltage. However, the physical origin of this improved performance is still unclear. Ta2O5 is an important archetype of a class of materials that possess an adaptive crystal structure that can respond easily to the presence of defects. Using first principles nudged elastic band calculations, we show that this adaptive crystal structure leads to low energy barriers for in-plane diffusion of oxygen vacancies in λ phase Ta2O5. Identified diffusion paths are associated with collective motion of neighboring atoms. The overall vacancy diffusion is anisotropic with higher diffusion barriers found for oxygen vacancy movement between Ta-O planes. Coupled with the fact that oxygen vacancy formation energy in Ta2O5 is relatively small, our calculated low diffusion barriers can help explain the low set voltage in Ta2O5 based resistive memory devices. Our work shows that other oxides with adaptive crystal structures could serve as potential candidates for resistive random access memory devices. We also discuss some general characteristics for ideal resistive RAM oxides that could be used in future computational material searches.

  7. Revealing the microbial community structure of clogging materials in dewatering wells differing in physico-chemical parameters in an open-cast mining area.

    Science.gov (United States)

    Wang, Juanjuan; Sickinger, Maren; Ciobota, Valerian; Herrmann, Martina; Rasch, Helfried; Rösch, Petra; Popp, Jürgen; Küsel, Kirsten

    2014-10-15

    Iron rich deposits cause clogging the pumps and pipes of dewatering wells in open-cast mines, interfering with their function; however, little is known about either the microbial community structure or their potential role in the formation of these deposits. The microbial diversity and abundance of iron-oxidizing and -reducing bacteria were compared in pipe deposit samples with different levels of encrustation from 16 wells at three lignite mining sites. The groundwater varied in pH values from slightly acidic (4.5) to neutral (7.3), Fe(II) concentrations from 0.48 to 7.55 mM, oxygen content from 1.8 to 5.8 mg L(-1), and dissolved organic carbon (DOC) from 1.43 to 12.59 mg L(-1). There were high numbers of bacterial 16S rRNA gene copies in deposits, up to 2.5 × 10(10) copies g(-1) wet weight. Pyrosequencing analysis of bacterial 16S rRNA genes revealed that Proteobacteria was the most abundant phylum (63.3% of the total reads on average), followed by Actinobacteria (10.2%) and Chloroflexi (6.4%). Gallionella-related sequences dominated the bacterial community of pipe deposits and accounted for 48% of total sequence reads. Pipe deposits with amorphous ferrihydrite and schwertmannite mostly contained Gallionella (up to 1.51 × 10(10) 16S rRNA gene copies g(-1) wet weight), while more crystalline deposits showed a higher bacterial diversity. Surprisingly, the abundance of Gallionella was not correlated with groundwater pH, oxygen, or DOC content. Sideroxydans-related 16S rRNA gene copy numbers were one order of magnitude less than Gallionella, followed by acidophilic Ferrovum-related groups. Iron reducing bacteria were detected at rather low abundance, as was expected given the low iron reduction potential, although they could be stimulated by lactate amendment. The overall high abundance of Gallionella suggests that microbes may make major contributions to pipe deposit formation irrespective of the water geochemistry. Their iron oxidation activity might

  8. Physicochemical and functional parameters of Cochlospermum vitifolium (bototo gum exudate

    Directory of Open Access Journals (Sweden)

    Maritza Coromoto Martínez

    2016-12-01

    Full Text Available The physicochemical parameters of Cochlospermum vitifolium they were evaluated and were linked to certain functional properties of industrial interest. The physicochemical parameters were determined by the classic methodology used for carbohydrates and the functional properties, as reported in the literature. The results obtained showed that the gum object of this study is low soluble in water, which corresponds with relatively high values of swelling indexes and water absorption capacity. Also, the intrinsic viscosity of the C. vitifolium exudate was related to a high molar mass, in the order of 106. Its emulsifying capacity is high, which is attributed to hydrophobic groups present in its structure. The gum gels at a minimum concentration, similar to that of the gum karaya (4.5%, but the gel that forms agglomerates, it is not uniform. The C. vitifolium gum exhibits important physicochemical and functional parameters which could serve as a criterion for testing its use in various industries.

  9. Physico-chemical properties

    Indian Academy of Sciences (India)

    Unknown

    indicate a need for an alternative. Allogeneic bone could overcome these limitations, but it bears the risk of infec- tions and immune response (Stevension 1999). So another possibility is to use material such as xenogeneic bone, which is morphologically and structurally similar to human bone. As compared to other methods ...

  10. Cone structure imaged with adaptive optics scanning laser ophthalmoscopy in eyes with nonneovascular age-related macular degeneration.

    Science.gov (United States)

    Zayit-Soudry, Shiri; Duncan, Jacque L; Syed, Reema; Menghini, Moreno; Roorda, Austin J

    2013-11-15

    To evaluate cone spacing using adaptive optics scanning laser ophthalmoscopy (AOSLO) in eyes with nonneovascular AMD, and to correlate progression of AOSLO-derived cone measures with standard measures of macular structure. Adaptive optics scanning laser ophthalmoscopy images were obtained over 12 to 21 months from seven patients with AMD including four eyes with geographic atrophy (GA) and four eyes with drusen. Adaptive optics scanning laser ophthalmoscopy images were overlaid with color, infrared, and autofluorescence fundus photographs and spectral domain optical coherence tomography (SD-OCT) images to allow direct correlation of cone parameters with macular structure. Cone spacing was measured for each visit in selected regions including areas over drusen (n = 29), at GA margins (n = 14), and regions without drusen or GA (n = 13) and compared with normal, age-similar values. Adaptive optics scanning laser ophthalmoscopy imaging revealed continuous cone mosaics up to the GA edge and overlying drusen, although reduced cone reflectivity often resulted in hyporeflective AOSLO signals at these locations. Baseline cone spacing measures were normal in 13/13 unaffected regions, 26/28 drusen regions, and 12/14 GA margin regions. Although standard clinical measures showed progression of GA in all study eyes, cone spacing remained within normal ranges in most drusen regions and all GA margin regions. Adaptive optics scanning laser ophthalmoscopy provides adequate resolution for quantitative measurement of cone spacing at the margin of GA and over drusen in eyes with AMD. Although cone spacing was often normal at baseline and remained normal over time, these regions showed focal areas of decreased cone reflectivity. These findings may provide insight into the pathophysiology of AMD progression. (ClinicalTrials.gov number, NCT00254605).

  11. Evaluation of the physicochemical properties of structured materials: metallic, polymeric and ceramic, for the treatment of sour gases; Evaluacion de las propiedades fisicoquimicas de materiales estructurados: metalico, polimerico y ceramico, para el tratamiento de gases acidos

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, A.; Chavez, R. H. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Olea, O.; Solis, D., E-mail: rosahilda.chavez@inin.gob.mx [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Cerro de Coatepec s/n, Ciudad Universitaria, 50100 Toluca, Estado de Mexico (Mexico)

    2013-07-01

    in this work the physicochemical properties of three structured materials: metallic, polymeric and ceramic, from Sulzer Brothers Limited brand, are studied in order to removal sour gases, by absorption process, in aqueous solution of Monoethanolamine (Mea), at 30% weight. Mechanical properties, chemical composition, morphology and corrosion resistance were determined, using different characterization techniques, such as: 1) mechanically, according to standard procedures Astm E-384-1990, 2) chemically, by the corrosion resistance in the presence of an electrochemical cell, in aqueous solution of H{sub 2}SO{sub 4}, 1 N by Astm G-5-1999, 3) morphologically by scanning electron microscopy technique, and 4) efficiency of separation, by the gas chromatography technique in order to determine the chemical absorption of CO{sub 2} by Mea. The ceramic material was the hardest with 700 Hk value and tensile strength of 90 MPa, likewise showed resistance to corrosion of 10.28 m py, separation efficiency of 74% CO{sub 2}, at 10 minutes. The metallic material had a hardness of 190 Hk and it was the most resistant of tension, with 831 MPa, and corrosion resistance of 780.4 x 10{sup -6} m py, likewise promoted CO{sub 2} separation efficiency of 90% during the evaluation. The polymeric material presented hardness of 20 Hk and 35 MPa and it was not suffered surface change with electrochemical attack, with 282.4 x 10{sup -6} m py, and separation efficiency of 88%. Therefore the polymer was the most ductile, with smooth surface and greater resistance with H{sub 2}SO{sub 4}. The metal material was more resistant to plastic deformation and more corrugated surface and the second resistance in the presence of acid medium in aqueous solutions. For all the above, the metallic material is recommended by its greater separation in the reduction of acid gases and the polymer due to its greater chemical resistance. (Author)

  12. Varying herbivore population structure correlates with lack of local adaptation in a geographic variable plant-herbivore interaction.

    Directory of Open Access Journals (Sweden)

    Rodrigo Cogni

    Full Text Available Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid moth Utetheisa ornatrix to its host plant, the pyrrolizidine alkaloid-bearing legume Crotalaria pallida, at the continental scale, but found no differentiation at the regional scale. In the present study, we sampled the same sites to investigate factors that may contribute to the lack of differentiation at the regional scale. We performed field observations that show that specialist and non-specialist polyphagous herbivore incidence varies among populations at both scales. With a series of common-garden experiments we show that some plant traits that may affect herbivory (pyrrolizidine alkaloids and extrafloral nectaries vary at the regional scale, while other traits (trichomes and nitrogen content just vary at the continental scale. These results, combined with our previous evidence for plant population differentiation based on larval performance on fresh fruits, suggest that U. ornatrix is subjected to divergent selection even at the regional scale. Finally, with a microsatellite study we investigated population structure of U. ornatrix. We found that population structure is not stable over time: we found population differentiation at the regional scale in the first year of sampling, but not in the second year. Unstable population structure of the herbivore is the most likely cause of the lack of regional adaptation.

  13. Varying Herbivore Population Structure Correlates with Lack of Local Adaptation in a Geographic Variable Plant-Herbivore Interaction

    Science.gov (United States)

    Cogni, Rodrigo; Trigo, José R.; Futuyma, Douglas J.

    2011-01-01

    Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid moth Utetheisa ornatrix to its host plant, the pyrrolizidine alkaloid-bearing legume Crotalaria pallida, at the continental scale, but found no differentiation at the regional scale. In the present study, we sampled the same sites to investigate factors that may contribute to the lack of differentiation at the regional scale. We performed field observations that show that specialist and non-specialist polyphagous herbivore incidence varies among populations at both scales. With a series of common-garden experiments we show that some plant traits that may affect herbivory (pyrrolizidine alkaloids and extrafloral nectaries) vary at the regional scale, while other traits (trichomes and nitrogen content) just vary at the continental scale. These results, combined with our previous evidence for plant population differentiation based on larval performance on fresh fruits, suggest that U. ornatrix is subjected to divergent selection even at the regional scale. Finally, with a microsatellite study we investigated population structure of U. ornatrix. We found that population structure is not stable over time: we found population differentiation at the regional scale in the first year of sampling, but not in the second year. Unstable population structure of the herbivore is the most likely cause of the lack of regional adaptation. PMID:22220208

  14. Limited Pollen Dispersal Contributes to Population Genetic Structure but Not Local Adaptation in Quercus oleoides Forests of Costa Rica.

    Directory of Open Access Journals (Sweden)

    Nicholas John Deacon

    Full Text Available Quercus oleoides Cham. and Schlect., tropical live oak, is a species of conservation importance in its southern range limit of northwestern Costa Rica. It occurs in high-density stands across a fragmented landscape spanning a contrasting elevation and precipitation gradient. We examined genetic diversity and spatial genetic structure in this geographically isolated and genetically distinct population. We characterized population genetic diversity at 11 nuclear microsatellite loci in 260 individuals from 13 sites. We monitored flowering time at 10 sites, and characterized the local environment in order to compare observed spatial genetic structure to hypotheses of isolation-by-distance and isolation-by-environment. Finally, we quantified pollen dispersal distances and tested for local adaptation through a reciprocal transplant experiment in order to experimentally address these hypotheses.High genetic diversity is maintained in the population and the genetic variation is significantly structured among sampled sites. We identified 5 distinct genetic clusters and average pollen dispersal predominately occurred over short distances. Differences among sites in flowering phenology and environmental factors, however, were not strictly associated with genetic differentiation. Growth and survival of upland and lowland progeny in their native and foreign environments was expected to exhibit evidence of local adaptation due to the more extreme dry season in the lowlands. Seedlings planted in the lowland garden experienced much higher mortality than seedlings in the upland garden, but we did not identify evidence for local adaptation.Overall, this study indicates that the Costa Rican Q. oleoides population has a rich population genetic history. Despite environmental heterogeneity and habitat fragmentation, isolation-by-distance and isolation-by-environment alone do not explain spatial genetic structure. These results add to studies of genetic structure by

  15. Integrated Flight/Structural Mode Control for Very Flexible Aircraft Using L1 Adaptive Output Feedback Controller

    Science.gov (United States)

    Che, Jiaxing; Cao, Chengyu; Gregory, Irene M.

    2012-01-01

    This paper explores application of adaptive control architecture to a light, high-aspect ratio, flexible aircraft configuration that exhibits strong rigid body/flexible mode coupling. Specifically, an L(sub 1) adaptive output feedback controller is developed for a semi-span wind tunnel model capable of motion. The wind tunnel mount allows the semi-span model to translate vertically and pitch at the wing root, resulting in better simulation of an aircraft s rigid body motion. The control objective is to design a pitch control with altitude hold while suppressing body freedom flutter. The controller is an output feedback nominal controller (LQG) augmented by an L(sub 1) adaptive loop. A modification to the L(sub 1) output feedback is proposed to make it more suitable for flexible structures. The new control law relaxes the required bounds on the unmatched uncertainty and allows dependence on the state as well as time, i.e. a more general unmatched nonlinearity. The paper presents controller development and simulated performance responses. Simulation is conducted by using full state flexible wing models derived from test data at 10 different dynamic pressure conditions. An L(sub 1) adaptive output feedback controller is designed for a single test point and is then applied to all the test cases. The simulation results show that the L(sub 1) augmented controller can stabilize and meet the performance requirements for all 10 test conditions ranging from 30 psf to 130 psf dynamic pressure.

  16. Adaptive Constrained Optimal Control Design for Data-Based Nonlinear Discrete-Time Systems With Critic-Only Structure.

    Science.gov (United States)

    Luo, Biao; Liu, Derong; Wu, Huai-Ning

    2017-10-03

    Reinforcement learning has proved to be a powerful tool to solve optimal control problems over the past few years. However, the data-based constrained optimal control problem of nonaffine nonlinear discrete-time systems has rarely been studied yet. To solve this problem, an adaptive optimal control approach is developed by using the value iteration-based Q-learning (VIQL) with the critic-only structure. Most of the existing constrained control methods require the use of a certain performance index and only suit for linear or affine nonlinear systems, which is unreasonable in practice. To overcome this problem, the system transformation is first introduced with the general performance index. Then, the constrained optimal control problem is converted to an unconstrained optimal control problem. By introducing the action-state value function, i.e., Q-function, the VIQL algorithm is proposed to learn the optimal Q-function of the data-based unconstrained optimal control problem. The convergence results of the VIQL algorithm are established with an easy-to-realize initial condition Q(0)(x,a)≽ 0. To implement the VIQL algorithm, the critic-only structure is developed, where only one neural network is required to approximate the Q-function. The converged Q-function obtained from the critic-only VIQL method is employed to design the adaptive constrained optimal controller based on the gradient descent scheme. Finally, the effectiveness of the developed adaptive control method is tested on three examples with computer simulation.

  17. Physicochemical, structural and induced ferromagnetic properties of ...

    Indian Academy of Sciences (India)

    The optical absorption properties were studied by diffuse reflection spectroscopy (DRS). Magnetic measurements reveal that the Co–In-codoped CdO powder has FM properties superimposed on paramagnetic (PM) behaviour. However, annealing in hydrogen atmosphere strongly boosts the created FMso that the ...

  18. Osteoinduction by biomaterials - Physicochemical and structural influences

    NARCIS (Netherlands)

    Habibovic, Pamela; Sees, Tara M.; van den Doel, Mirella; van Blitterswijk, Clemens; de Groot, K.

    2006-01-01

    Osteoinduction by biomaterials has been shown to be a real phenomenon by many investigators in the last decade. The exact mechanism of this phenomenon is, however, still largely unknown. This in vivo study in goats was performed to get insight into processes governing the phenomenon of

  19. Physicochemical, structural and induced ferromagnetic properties of ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 7 ... The electronic medium in the host CdO lattice,which carries the long-range spin–spin ( S . S ) exchange interaction between localised Co 2 + (3d) spins of dopant ions, was further developed by annealing in hydrogen gas (hydrogenation). The crystalline ...

  20. PHYSICOCHEMICAL AND STRUCTURAL-PROPERTIES OF THE SURFACES OF PEPTOSTREPTOCOCCUS-MICROS AND STREPTOCOCCUS-MITIS AS COMPARED TO THOSE OF MUTANS STREPTOCOCCI, STREPTOCOCCUS-SANGUIS AND STREPTOCOCCUS-SALIVARIUS

    NARCIS (Netherlands)

    COWAN, MM; VANDERMEI, HC; ROUXHET, PG; BUSSCHER, HJ

    1992-01-01

    The surface properties of nine Streptococcus mitis and four Peptostreptococcus micros strains from the oral cavity were examined and compared with a large group of oral streptococci. Zeta potential and contact angle measurements were employed to determine physico-chemical cell surface properties. In

  1. Adaptive Positive Position Feedback Control of Flexible Aircraft Structures Using Piezoelectric Actuators

    Science.gov (United States)

    2014-03-27

    Aeronautics and Space Administration. “F/A-18 High Alpha Research Vehicle”. http://www.nasa.gov/centers/ dryden /multimedia/imagegallery/F-18HARV/ index.html...lowerAccordion-set1-slide10, April 1989. 18 February 2014. [2] John D. Anderson. Fundamentals of Aerodynamics. McGraw-Hill, New York, 5th edition, 2011...Krishnakumar, John Kaneshige, and Pascal Nespeca. “Dynamics and Adaptive Control for Stability Recovery of Damaged Asymmetric Aircraft”. Technical report

  2. Revisiting the factor structure of the Kirton Adaption-Innovation Inventory.

    Science.gov (United States)

    Im, Subin; Hu, Michael Y

    2005-04-01

    The original Kirton Adaption-Innovation Inventory, used to measure innovative (as opposed to adaptive) individual cognitive styles, has been reported to have three factors: Sufficiency of Originality, Efficiency, and Rule/Group Conformity. In exploring the construct validity of the Kirton Adaption-Innovation Inventory, findings from a 2003 study by Im, Hu, and Toh showed the existence of two subdimensions of the Sufficiency of Originality factor-Idea Generation and Preference for Change. In this study, using a sample of 356 household participants, with an average age of 56.0 yr. (SD = 14.0), average income of dollar 39,700 (SD = dollar 19,200), and average of 15.0 yr. of education (SD = 2), from the Arkansas Household Research Panel, we conducted factor analyses. The results specific to our selected sample indicate that a four-factor model recognizing the two subdimensions of Sufficiency of Originality has a better fit than the original three-factor model.

  3. Robust Comparison of the Linear Model Structures in Self-tuning Adaptive Control

    DEFF Research Database (Denmark)

    Zhou, Jianjun; Conrad, Finn

    1989-01-01

    The Generalized Predictive Controller (GPC) is extended to the systems with a generalized linear model structure which contains a number of choices of linear model structures. The Recursive Prediction Error Method (RPEM) is used to estimate the unknown parameters of the linear model structures...... to constitute a GPC self-tuner. Different linear model structures commonly used are compared and evaluated by applying them to the extended GPC self-tuner as well as to the special cases of the GPC, the GMV and MV self-tuners. The simulation results show how the choice of model structure affects the input...

  4. Adaptation of NASTRAN to an integrated system of structural design analysis

    Science.gov (United States)

    Haggenmacher, G. W.

    1972-01-01

    Efforts to integrate NASTRAN into a complete structural analysis system for use by large airframe design projects are discussed. NASTRAN was implemented as a major finite element structural analysis program to determine the static and dynamic behavior of complete airframes, as well as structural components. This requires modifications and additions to NASTRAN, to communicate with an existing system, and to provide facilities needed to work within the integrated structural analysis. For this purpose, several special DMAP modules were developed and introduced into the CALAC version of the NASTRAN system.

  5. Adaptive Multiresolution Methods: Practical issues on Data Structures, Implementation and Parallelization*

    Directory of Open Access Journals (Sweden)

    Bachmann M.

    2011-12-01

    Full Text Available The concept of fully adaptive multiresolution finite volume schemes has been developed and investigated during the past decade. Here grid adaptation is realized by performing a multiscale decomposition of the discrete data at hand. By means of hard thresholding the resulting multiscale data are compressed. From the remaining data a locally refined grid is constructed. The aim of the present work is to give a self-contained overview on the construction of an appropriate multiresolution analysis using biorthogonal wavelets, its efficient realization by means of hash maps using global cell identifiers and the parallelization of the multiresolution-based grid adaptation via MPI using space-filling curves. Le concept des schémas de volumes finis multi-échelles et adaptatifs a été développé et etudié pendant les dix dernières années. Ici le maillage adaptatif est réalisé en effectuant une décomposition multi-échelle des données discrètes proches. En les tronquant à l’aide d’une valeur seuil fixée, les données multi-échelles obtenues sont compressées. A partir de celles-ci, le maillage est raffiné localement. Le but de ce travail est de donner un aperçu concis de la construction d’une analyse appropriée de multiresolution utilisant les fonctions ondelettes biorthogonales, de son efficacité d’application en terme de tables de hachage en utilisant des identification globales de cellule et de la parallélisation du maillage adaptatif multirésolution via MPI à l’aide des courbes remplissantes.

  6. Optimizing the data acquisition rate for a remotely controllable structural monitoring system with parallel operation and self-adaptive sampling

    International Nuclear Information System (INIS)

    Sheng, Wenjuan; Guo, Aihuang; Liu, Yang; Azmi, Asrul Izam; Peng, Gang-Ding

    2011-01-01

    We present a novel technique that optimizes the real-time remote monitoring and control of dispersed civil infrastructures. The monitoring system is based on fiber Bragg gating (FBG) sensors, and transfers data via Ethernet. This technique combines parallel operation and self-adaptive sampling to increase the data acquisition rate in remote controllable structural monitoring systems. The compact parallel operation mode is highly efficient at achieving the highest possible data acquisition rate for the FBG sensor based local data acquisition system. Self-adaptive sampling is introduced to continuously coordinate local acquisition and remote control for data acquisition rate optimization. Key issues which impact the operation of the whole system, such as the real-time data acquisition rate, data processing capability, and buffer usage, are investigated. The results show that, by introducing parallel operation and self-adaptive sampling, the data acquisition rate can be increased by several times without affecting the system operating performance on both local data acquisition and remote process control

  7. Structural adaptations of octaheme nitrite reductases from haloalkaliphilic Thioalkalivibrio bacteria to alkaline pH and high salinity.

    Directory of Open Access Journals (Sweden)

    Anna Popinako

    Full Text Available Bacteria Tv. nitratireducens and Tv. paradoxus from soda lakes grow optimally in sodium carbonate/NaCl brines at pH range from 9.5 to 10 and salinity from 0.5 to 1.5 M Na+. Octaheme nitrite reductases (ONRs from haloalkaliphilic bacteria of genus Thioalkalivibrio are stable and active in a wide range of pH (up to 11 and salinity (up to 1 M NaCl. To establish adaptation mechanisms of ONRs from haloalkaliphilic bacteria a comparative analysis of amino acid sequences and structures of ONRs from haloalkaliphilic bacteria and their homologues from non-halophilic neutrophilic bacteria was performed. The following adaptation strategies were observed: (1 strategies specific for halophilic and alkaliphilic proteins (an increase in the number of aspartate and glutamate residues and a decrease in the number of lysine residues on the protein surface, (2 strategies specific for halophilic proteins (an increase in the arginine content and a decrease in the number of hydrophobic residues on the solvent-accessible protein surface, (3 strategies specific for alkaliphilic proteins (an increase in the area of intersubunit hydrophobic contacts. Unique adaptation mechanism inherent in the ONRs from bacteria of genus Thioalkalivibrio was revealed (an increase in the core in the number of tryptophan and phenylalanine residues, and an increase in the number of small side chain residues, such as alanine and valine, in the core.

  8. An Adaptive Spectrally Weighted Structure Tensor Applied to Tensor Anisotropic Nonlinear Diffusion for Hyperspectral Images

    Science.gov (United States)

    Marin Quintero, Maider J.

    2013-01-01

    The structure tensor for vector valued images is most often defined as the average of the scalar structure tensors in each band. The problem with this definition is the assumption that all bands provide the same amount of edge information giving them the same weights. As a result non-edge pixels can be reinforced and edges can be weakened…

  9. Crystal Structure Predictions Using Adaptive Genetic Algorithm and Motif Search methods

    Science.gov (United States)

    Ho, K. M.; Wang, C. Z.; Zhao, X.; Wu, S.; Lyu, X.; Zhu, Z.; Nguyen, M. C.; Umemoto, K.; Wentzcovitch, R. M. M.

    2017-12-01

    Material informatics is a new initiative which has attracted a lot of attention in recent scientific research. The basic strategy is to construct comprehensive data sets and use machine learning to solve a wide variety of problems in material design and discovery. In pursuit of this goal, a key element is the quality and completeness of the databases used. Recent advance in the development of crystal structure prediction algorithms has made it a complementary and more efficient approach to explore the structure/phase space in materials using computers. In this talk, we discuss the importance of the structural motifs and motif-networks in crystal structure predictions. Correspondingly, powerful methods are developed to improve the sampling of the low-energy structure landscape.

  10. IMAGING WITH MULTIMODAL ADAPTIVE-OPTICS OPTICAL COHERENCE TOMOGRAPHY IN MULTIPLE EVANESCENT WHITE DOT SYNDROME: THE STRUCTURE AND FUNCTIONAL RELATIONSHIP.

    Science.gov (United States)

    Labriola, Leanne T; Legarreta, Andrew D; Legarreta, John E; Nadler, Zach; Gallagher, Denise; Hammer, Daniel X; Ferguson, R Daniel; Iftimia, Nicusor; Wollstein, Gadi; Schuman, Joel S

    2016-01-01

    To elucidate the location of pathological changes in multiple evanescent white dot syndrome (MEWDS) with the use of multimodal adaptive optics (AO) imaging. A 5-year observational case study of a 24-year-old female with recurrent MEWDS. Full examination included history, Snellen chart visual acuity, pupil assessment, intraocular pressures, slit lamp evaluation, dilated fundoscopic exam, imaging with Fourier-domain optical coherence tomography (FD-OCT), blue-light fundus autofluorescence (FAF), fundus photography, fluorescein angiography, and adaptive-optics optical coherence tomography. Three distinct acute episodes of MEWDS occurred during the period of follow-up. Fourier-domain optical coherence tomography and adaptive-optics imaging showed disturbance in the photoreceptor outer segments (PR OS) in the posterior pole with each flare. The degree of disturbance at the photoreceptor level corresponded to size and extent of the visual field changes. All findings were transient with delineation of the photoreceptor recovery from the outer edges of the lesion inward. Hyperautofluorescence was seen during acute flares. Increase in choroidal thickness did occur with each active flare but resolved. Although changes in the choroid and RPE can be observed in MEWDS, Fourier-domain optical coherence tomography, and multimodal adaptive optics imaging localized the visually significant changes seen in this disease at the level of the photoreceptors. These transient retinal changes specifically occur at the level of the inner segment ellipsoid and OS/RPE line. En face optical coherence tomography imaging provides a detailed, yet noninvasive method for following the convalescence of MEWDS and provides insight into the structural and functional relationship of this transient inflammatory retinal disease.

  11. Numerical study of self-adaptive vibration suppression for flexible structure using interior inlay viscous fluid unit method

    Science.gov (United States)

    Zhang, Xiongwen; Li, Jun; Xu, Hui; Li, Guojun

    2006-11-01

    This paper investigates the usage of an interior inlay viscous fluid unit as a new vibration suppression method for flexible structures via numerical simulations. The first and second modes of vibration for a beam have been calculated using the commercial computational fluid dynamic package Fluent6.1, together with the liquid surface distribution and the fluid force. The calculated results show that the inlay fluid unit has suppressive effects on flexible structures. The liquid converges self-adaptively to locations of larger vibrations. The fluid force varies with the beam vibration at a phase difference of more than 180°. Thus the fluid force suppresses the beam vibration at most of the time.

  12. Fully Adaptive Slit-tube Structures with Electrically Integrated Smart Joints, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to NASA's need for compact, low-cost in-space modular construction components, Roccor proposes to develop structural elements designed for rapid in-space...

  13. Adaptive pressure-controlled cellular structures for shape morphing: II. Numerical and experimental validation

    International Nuclear Information System (INIS)

    Luo, Quantian; Tong, Liyong

    2013-01-01

    This part presents finite element analysis to verify the present formulations on mechanics of the pressurized cellular structures derived in Part I and experimental testing for a pressurized cellular actuator to demonstrate feasibility and realization of the proposed pressurized cellular structures. Linear and nonlinear finite element analyses are implemented in a commercial finite element analysis package and the numerical results are compared with those of the novel formulations given in Part I. A pressurized cellular structure specimen with 3 cells is fabricated and tested. The fabricated 3-cell cellular structure is capable of yielding a free actuation strain of around 24%. The measured pressure-induced displacement and blocking force compare favorably with the numerical results predicted by the finite element analysis and analytical formulations. (paper)

  14. Brazilian version of the Structured Interview for Disorders of Extreme Stress - Revised (SIDES-R: adaptation and validation process

    Directory of Open Access Journals (Sweden)

    Jessica Camargo

    2013-12-01

    Full Text Available BACKGROUND: Posttraumatic stress disorder (PTSD contemplates the impact of acute traumatic events, but the literature indicates that this is not true for chronic exposure to stress. In this sense, the category disorders of extreme stress not otherwise specified (DESNOS has been proposed to characterize the behavior and cognitive alterations derived from exposure to continuous early life stress. The Structured Interview for Disorders of Extreme Stress - Revised (SIDES-R was developed to investigate and measure DESNOS. Considering the lack of instruments designed to assess DESNOS, especially in Brazil, the aim of this study was to translate, adapt, and validate the contents of SIDES-R to Brazilian Portuguese (SIDES-R-BR. METHOD: The original interview was subjected to translation, back-translation, semantic equivalence and conceptual correspondence analyses by naive and specialized judges, respectively, an acceptability trial, and inter-rater validity analysis. RESULTS: The interview underwent semantic and structural adaptations considering the Brazilian culture. The final version, SIDES-R-BR, showed a mean understanding score of 4.98 on a 5-point verbal rating scale, in addition to a kappa coefficient of 0.853. CONCLUSION: SIDES-R-BR may be a useful tool in the investigation of DESNOS and contributes a valuable input to clinical research in Brazil. The availability of the instrument allows to test symptoms with adequate reliability, as verified by the kappa coefficient and translation steps.

  15. Computational Error Estimates and Adaptive Processes for Some Nonlinear Structural Problems.

    Science.gov (United States)

    1981-07-01

    24] H. B. Keller, Global Homotopies and Newton Methods ,in "Recent Advances in Numerical Analysis " ed. by C. deBoor, G. H. Golub, Academic Press...649-662. [34] W. Rheinboldt, Numerical Analysis of Continuation Methods for Nonlinear Structural Problems, Computers and Structures 13, 1981, 103-114...type interest centers on an analysis of the shape and features of the equilibrium surface. After some general remarks about such surfaces and the

  16. The impact of natural transformation on adaptation in spatially structured bacterial populations

    OpenAIRE

    Moradigaravand, Danesh; Engelstädter, Jan

    2014-01-01

    Background Recent studies have demonstrated that natural transformation and the formation of highly structured populations in bacteria are interconnected. In spite of growing evidence about this connection, little is known about the dynamics of natural transformation in spatially structured bacterial populations. Results In this work, we model the interdependency between the dynamics of the bacterial gene pool and those of environmental DNA in space to dissect the effect of transformation on ...

  17. Chaos control and generalized projective synchronization of heavy symmetric chaotic gyroscope systems via Gaussian radial basis adaptive variable structure control

    International Nuclear Information System (INIS)

    Farivar, Faezeh; Aliyari Shoorehdeli, Mahdi; Nekoui, Mohammad Ali; Teshnehlab, Mohammad

    2012-01-01

    Highlights: ► A systematic procedure for GPS of unknown heavy chaotic gyroscope systems. ► Proposed methods are based on Lyapunov stability theory. ► Without calculating Lyapunov exponents and Eigen values of the Jacobian matrix. ► Capable to extend for a variety of chaotic systems. ► Useful for practical applications in the future. - Abstract: This paper proposes the chaos control and the generalized projective synchronization methods for heavy symmetric gyroscope systems via Gaussian radial basis adaptive variable structure control. Because of the nonlinear terms of the gyroscope system, the system exhibits chaotic motions. Occasionally, the extreme sensitivity to initial states in a system operating in chaotic mode can be very destructive to the system because of unpredictable behavior. In order to improve the performance of a dynamic system or avoid the chaotic phenomena, it is necessary to control a chaotic system with a periodic motion beneficial for working with a particular condition. As chaotic signals are usually broadband and noise like, synchronized chaotic systems can be used as cipher generators for secure communication. This paper presents chaos synchronization of two identical chaotic motions of symmetric gyroscopes. In this paper, the switching surfaces are adopted to ensure the stability of the error dynamics in variable structure control. Using the neural variable structure control technique, control laws are established which guarantees the chaos control and the generalized projective synchronization of unknown gyroscope systems. In the neural variable structure control, Gaussian radial basis functions are utilized to on-line estimate the system dynamic functions. Also, the adaptation laws of the on-line estimator are derived in the sense of Lyapunov function. Thus, the unknown gyro systems can be guaranteed to be asymptotically stable. Also, the proposed method can achieve the control objectives. Numerical simulations are presented to

  18. Spatio-Temporal Video Object Segmentation via Scale-Adaptive 3D Structure Tensor

    Directory of Open Access Journals (Sweden)

    Hai-Yun Wang

    2004-06-01

    Full Text Available To address multiple motions and deformable objects' motions encountered in existing region-based approaches, an automatic video object (VO segmentation methodology is proposed in this paper by exploiting the duality of image segmentation and motion estimation such that spatial and temporal information could assist each other to jointly yield much improved segmentation results. The key novelties of our method are (1 scale-adaptive tensor computation, (2 spatial-constrained motion mask generation without invoking dense motion-field computation, (3 rigidity analysis, (4 motion mask generation and selection, and (5 motion-constrained spatial region merging. Experimental results demonstrate that these novelties jointly contribute much more accurate VO segmentation both in spatial and temporal domains.

  19. Strategic Adaptation

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    2015-01-01

    This article provides an overview of theoretical contributions that have influenced the discourse around strategic adaptation including contingency perspectives, strategic fit reasoning, decision structure, information processing, corporate entrepreneurship, and strategy process. The related...... concepts of strategic renewal, dynamic managerial capabilities, dynamic capabilities, and strategic response capabilities are discussed and contextualized against strategic responsiveness. The insights derived from this article are used to outline the contours of a dynamic process of strategic adaptation...

  20. Physicochemical conditions in affecting the distribution of spring phytoplankton community

    Science.gov (United States)

    Wei, Yuqiu; Liu, Haijiao; Zhang, Xiaodong; Xue, Bing; Munir, Sonia; Sun, Jun

    2017-11-01

    To better understand the physicochemical conditions in affecting regional distribution of phytoplankton community, one research cruise was carried out in the Bohai Sea and Yellow Sea during 3rd and 23th May, 2010. The phytoplankton community, including Bacillariophyta (105 taxa), Pyrrophyta (54 taxa), Chrysophyta (1 taxon) and Chlorophyta (2 taxa), had been identified and clearly described from six ecological provinces. And, the six ecological provinces were partitioned based on the top twenty dominant species related with notable physicochemical parameters. In general, the regional distributions of phytoplankton ecological provinces were predominantly influenced by the physicochemical properties induced by the variable water masses and circulations. The predominant diatoms in most of water samples showed well adaptability in turbulent and eutrophic conditions. However, several species of dinoflagellates e.g., Protoperidinium conicum, Protoperidinium triestinum, Protoperidinium sp. and Gymnodinium lohmanni preferred warmer, saltier and nutrient-poor environment. Moreover, the dinoflagellates with high frequency in the Yellow Sea might be transported from the Yellow Sea Warm Current. The horizontal distribution of phytoplankton was depicted by diatoms and controlled by phosphate concentration, while the vertical distribution was mainly supported by light and nutrients availability in the subsurface and bottom layers, respectively.

  1. An assay of the physicochemical characters of radiation sterilized plastic transfusion

    International Nuclear Information System (INIS)

    Liu Keliang

    1988-01-01

    In order to adapt radiation sterilization to the need of clinical use by means of 3 H-TdR incorporation, the physicochemical charaters were studied between irradiated and unirradiated plastic transfusion sets. The results showed that a large radiation dose of 2.5 to 10 x 10 4 Gy had no damage on the plastic transfusion sets, nor toxic to human

  2. EDITORIAL: Adaptive and active materials: Selected papers from the ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 10) (Philadelphia, PA, USA, 28 September-1 October 2010) Adaptive and active materials: Selected papers from the ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 10) (Philadelphia, PA, USA, 28 September-1 October 2010)

    Science.gov (United States)

    Brei, Diann

    2011-09-01

    The third annual meeting of the AMSE/AIAA Smart Materials, Adaptive Structures and Intelligent Systems Conference (SMASIS) took place in the heart of historic Philadelphia's cultural district, and included a pioneer banquet in the National Constitutional Center. The applications emphasis of the 2010 conference was reflected in keynote talks by Dr Alan Taub, vice president of General Motors global research and development, 'Smart materials in the automotive industry'; Dr Charles R Farrar, engineering institute leader at Los Alamos National Laboratory, 'Future directions for structural health monitoring of civil engineering infrastructure'; and Professor Christopher S Lynch of the University of California Los Angeles, 'Ferroelectric materials and their applications'. The SMASIS conference was divided into six technical symposia each of which included basic research, applied technological design and development, and industrial and governmental integrated system and application demonstrations. The six symposia were: SYMP 1 Multifunctional Materials; SYMP 2 Active Materials, Mechanics and Behavior; SYMP 3 Modeling, Simulation and Control; SYMP 4 Enabling Technologies and Integrated System Design; SYMP 5 Structural Health Monitoring/NDE; and SYMP 6 Bio-inspired Smart Materials and Structures. In addition, the conference introduced a new student and young professional development symposium. Authors of papers in the materials areas (symposia 1, 2 and 6) were invited to write a full journal article on their presentation topic for publication in this special issue of Smart Materials and Structures. This set of papers demonstrates the exceptional quality and originality of the conference presentations. We are appreciative of their efforts in producing this collection of highly relevant articles on smart materials.

  3. Structure and flexibility adaptation in nonspecific and specific protein-DNA complexes

    NARCIS (Netherlands)

    Kalodimos, Ch.; Biris, N.; Bonvin, A.M.J.J.; Levandoski, M.M.; Guennuegues, M.; Boelens, R.; Kaptein, R.

    2004-01-01

    Interaction of regulatory DNA binding proteins with their target sites is usually preceded by binding to nonspecific DNA. This speeds up the search for the target site by several orders of magnitude. We report the solution structure and dynamics of the complex of a dimeric lac repressor DNA binding

  4. Applying Adaptive Swarm Intelligence Technology with Structuration in Web-Based Collaborative Learning

    Science.gov (United States)

    Huang, Yueh-Min; Liu, Chien-Hung

    2009-01-01

    One of the key challenges in the promotion of web-based learning is the development of effective collaborative learning environments. We posit that the structuration process strongly influences the effectiveness of technology used in web-based collaborative learning activities. In this paper, we propose an ant swarm collaborative learning (ASCL)…

  5. Genetic diversity and population structure of locally adapted South African chicken lines: Implications for conservation.

    NARCIS (Netherlands)

    Marle-Koster, van E.; Hefer, C.A.; Nel, L.H.; Groenen, M.A.M.

    2008-01-01

    In this study microsatellite markers were applied to investigate the genetic diversity and population structure of the six local chicken lines kept in the “Fowls for Africa” program, for better clarification of parameters for breed differentiation and genetic conservation of this valuable resource.

  6. The factorial structure of job-related affective well-being: Polish adaptation of the Warr's measure.

    Science.gov (United States)

    Mielniczuk, Emilia; Łaguna, Mariola

    2018-02-16

    The first aim of the study reported in this article was to test the factorial structure of job-related affect in a Polish sample. The second aim was to develop the Polish adaptation of the Warr's job-related affective well-being measure published in 1990, which is designed to assess 4 types of affect at work: anxiety, comfort, depression, enthusiasm. A longitudinal study design with 2 measurement times was used for verifying the psychometric properties of the Polish version of the measure. The final sample consisted of 254 Polish employees from different professions. Participants were asked to fill in a set of questionnaires consisting of measures capturing job-related affective well-being, mood, and turnover intention. The first step of analysis was to test the theoretically-based structure of the job-related affective well-being measure in a Polish sample. The confirmatory factor analysis revealed that a 4-factor model best describes the structure of the measure in comparison to 5 alternative models. Next, reliability of this measure was assessed. All scales achieved good internal consistency and acceptable test-retest reliability after 2 weeks. Finally, the convergent and discriminant validity as well as the criterion and predictive validity of all job-related affective well-being scales was confirmed, based on correlations between job-related affect and mood as well as turnover intention. The results suggest that the Polish adaptation of Warr's job-related affective well-being measure can be used by scientists as well as by practitioners who aim at assessing 4 types of affective well-being at a work context. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  7. Conception et exploitation d'une structure active pour une aile laminaire adaptative experimentale

    Science.gov (United States)

    Coutu, Daniel

    This doctoral research contributed to the success of the project CRIAQ 7.1, demonstrating the capability of a morphing laminar wing to reduce fuel consumption. Respectively, this thesis shows the design of the experimental wing and its operation in a subsonic wind tunnel (Mach numbers of 0.2 to 0.3 with angles of attack between -1 and 2°). First of all, the morphing wing is formed of a composite laminate linked to an actuation system to build an active structure capable of modifying the wing upper surface geometry. The design was performed using a new developed methodology to solve aero-structural problems. Using ANSYS software, the finite elements method was applied to model the different possible active structure configurations Aerodynamic loads applied over the active structure as well as targeted morphed geometries have been provided by the Ecole Polytechnique team. Next, laminar flow enhancements allowed by each active structure configuration we' re evaluated using the aerodynamic solver XFoil 6.96. A best trade-off between aerodynamic performance and energy needed for wing morphing was found using a multi-objective optimization technique. Among the retained stable configurations, a 4-ply composite laminated shell driven by 2 actuation lines was retained. Thereafter, the research effort focused on the exploitation of the morphing capabilities of the experimental wing over each given set of flow conditions. Therefore, once the prototype was built, the structural model was refined, calibrated and coupled with the aerodynamic solver to accurately predict the aero-structural behavior in the wind tunnel. Optimal morphing wing shapes were numerically calculated using a generalized pattern search algorithm and a local search routine to refine the solution. In the wind tunnel, this open-loop control approach allowed an average 25% laminar flow regime extension over the wing prototype upper surface. Consequently, an average 18.5% profile drag reduction was measured by

  8. Adaptive optics for in-vivo exploration of human retinal structures

    Science.gov (United States)

    Paques, Michel; Meimon, Serge; Grieve, Kate; Rossant, Florence

    2017-06-01

    Adaptive optics (AO)-enhanced imaging of the retina is now reaching a level of technical maturity which fosters its expanding use in research and clinical centers in the world. By achieving wavelength-limited resolution it did not only allow a better observation of retinal substructures already visible by other means, it also broke anatomical frontiers such as individual photoreceptors or vessel walls. The clinical applications of AO-enhanced imaging has been slower than that of optical coherence tomography because of the combination of technical complexity, costs and the paucity of interpretative scheme of complex data. In several diseases, AO-enhanced imaging has already proven to provide added clinical value and quantitative biomarkers. Here, we will review some of the clinical applications of AO-enhanced en face imaging, and trace perspectives to improve its clinical pertinence in these applications. An interesting perspective is to document cell motion through time-lapse imaging such as during agerelated macular degeneration. In arterial hypertension, the possibility to measure parietal thickness and perform fine morphometric analysis is of interest for monitoring patients. In the near future, implementation of novel approaches and multimodal imaging, including in particular optical coherence tomography, will undoubtedly expand our imaging capabilities. Tackling the technical, scientific and medical challenges offered by high resolution imaging are likely to contribute to our rethinking of many retinal diseases, and, most importantly, may find applications in other areas of medicine.

  9. Spatial Variability of Soil Morphorlogical and Physico-Chemical ...

    African Journals Online (AJOL)

    Spatial Variability of Soil Morphorlogical and Physico-Chemical Properties in Ladoke Akintola University of Technology Cashew Plantation, Ogbomoso. ... Colour (AP, B1 B2 and B3), structure (B2 and B3), stoniness (B1, B2 and B3), concretion (AP B1, B2 and B3) and boundary forms (B1, B2 and B3) have extremely ...

  10. Novel graphene-based nanostructures: physicochemical properties and applications

    International Nuclear Information System (INIS)

    Chernozatonskii, L A; Sorokin, P B; Artukh, A A

    2014-01-01

    The review concerns graphene-based nanostructures including graphene nanoribbons a few nanometres wide, structures functionalized with hydrogen and fluorine atoms as well as pure carbon composites. The physicochemical properties and the chemical engineering methods for their fabrication are considered. Methods for solving problems in modern nanotechnology are discussed. Possible applications of graphene and graphene-based nanostructures in various devices are outlined. The bibliography includes 286 references

  11. Adaptability and selectivity of human peroxisome proliferator-activated receptor (PPAR) pan agonists revealed from crystal structures

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Takuji; Toyota, Kenji; Waku, Tsuyoshi; Hirakawa, Yuko; Nagasawa, Naoko [The Takara Bio Endowed Division, Department of Biomolecular Recognition, Institute for Protein Research, Osaka University, Open Laboratories of Advanced Bioscience and Biotechnology, 6-2-3 Furuedai, Suita, Osaka 565-0874 (Japan); Kasuga, Jun-ichi; Hashimoto, Yuichi; Miyachi, Hiroyuki [Institute of Molecular and Cellular Biosciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Morikawa, Kosuke, E-mail: morikako@protein.osaka-u.ac.jp [The Takara Bio Endowed Division, Department of Biomolecular Recognition, Institute for Protein Research, Osaka University, Open Laboratories of Advanced Bioscience and Biotechnology, 6-2-3 Furuedai, Suita, Osaka 565-0874 (Japan)

    2009-08-01

    The structures of the ligand-binding domains (LBDs) of human peroxisome proliferator-activated receptors (PPARα, PPARγ and PPARδ) in complexes with a pan agonist, an α/δ dual agonist and a PPARδ-specific agonist were determined. The results explain how each ligand is recognized by the PPAR LBDs at an atomic level. Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone receptor family, which is defined as transcriptional factors that are activated by the binding of ligands to their ligand-binding domains (LBDs). Although the three PPAR subtypes display different tissue distribution patterns and distinct pharmacological profiles, they all are essentially related to fatty-acid and glucose metabolism. Since the PPARs share similar three-dimensional structures within the LBDs, synthetic ligands which simultaneously activate two or all of the PPARs could be potent candidates in terms of drugs for the treatment of abnormal metabolic homeostasis. The structures of several PPAR LBDs were determined in complex with synthetic ligands, derivatives of 3-(4-alkoxyphenyl)propanoic acid, which exhibit unique agonistic activities. The PPARα and PPARγ LBDs were complexed with the same pan agonist, TIPP-703, which activates all three PPARs and their crystal structures were determined. The two LBD–ligand complex structures revealed how the pan agonist is adapted to the similar, but significantly different, ligand-binding pockets of the PPARs. The structures of the PPARδ LBD in complex with an α/δ-selective ligand, TIPP-401, and with a related δ-specific ligand, TIPP-204, were also determined. The comparison between the two PPARδ complexes revealed how each ligand exhibits either a ‘dual selective’ or ‘single specific’ binding mode.

  12. Adaptability and selectivity of human peroxisome proliferator-activated receptor (PPAR) pan agonists revealed from crystal structures

    International Nuclear Information System (INIS)

    Oyama, Takuji; Toyota, Kenji; Waku, Tsuyoshi; Hirakawa, Yuko; Nagasawa, Naoko; Kasuga, Jun-ichi; Hashimoto, Yuichi; Miyachi, Hiroyuki; Morikawa, Kosuke

    2009-01-01

    The structures of the ligand-binding domains (LBDs) of human peroxisome proliferator-activated receptors (PPARα, PPARγ and PPARδ) in complexes with a pan agonist, an α/δ dual agonist and a PPARδ-specific agonist were determined. The results explain how each ligand is recognized by the PPAR LBDs at an atomic level. Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone receptor family, which is defined as transcriptional factors that are activated by the binding of ligands to their ligand-binding domains (LBDs). Although the three PPAR subtypes display different tissue distribution patterns and distinct pharmacological profiles, they all are essentially related to fatty-acid and glucose metabolism. Since the PPARs share similar three-dimensional structures within the LBDs, synthetic ligands which simultaneously activate two or all of the PPARs could be potent candidates in terms of drugs for the treatment of abnormal metabolic homeostasis. The structures of several PPAR LBDs were determined in complex with synthetic ligands, derivatives of 3-(4-alkoxyphenyl)propanoic acid, which exhibit unique agonistic activities. The PPARα and PPARγ LBDs were complexed with the same pan agonist, TIPP-703, which activates all three PPARs and their crystal structures were determined. The two LBD–ligand complex structures revealed how the pan agonist is adapted to the similar, but significantly different, ligand-binding pockets of the PPARs. The structures of the PPARδ LBD in complex with an α/δ-selective ligand, TIPP-401, and with a related δ-specific ligand, TIPP-204, were also determined. The comparison between the two PPARδ complexes revealed how each ligand exhibits either a ‘dual selective’ or ‘single specific’ binding mode

  13. MO-FG-CAMPUS-IeP2-04: Multiple Penalties with Different Orders for Structure Adaptive CBCT Reconstruction

    International Nuclear Information System (INIS)

    Shi, Q; Cheng, P; Tan, S; Tan, S; Wang, J

    2016-01-01

    Purpose: To combine total variation (TV) and Hessian penalty in a structure adaptive way for cone-beam CT (CBCT) reconstruction. Methods: TV is a widely used first order penalty with good ability in suppressing noise and preserving edges but leads to the staircase effect in regions with smooth intensity transition. The second order Hessian penalty can effectively suppress the staircase effect with extra cost of blurring object edges. To take the best of both penalties we proposed a novel method to combine both for CBCT reconstruction in a structure adaptive way. The proposed method adaptively determined the weight of each penalty according to the geometry of local regions. An specially-designed exponent term with image gradient involved was used to characterize the local geometry such that the weights for Hessian and TV were 1 and 0 respectively at uniform local regions and 0 and 1 at edge regions. For other local regions the weights varied from 0 to 1. The objective functional was minimized using the majorzationminimization approach. We evaluated the proposed method on a modified 3D shepp-logan and a CatPhan 600 phantom. The full-width-at-halfmaximum (FWHM) and contrast-to-noise (CNR) were calculated. Results: For 3D shepp-logan the reconstructed images using TV had an obvious staircase effect while those using the proposed method and Hessian preserved the smooth transition regions well. FWHMs of the proposed method TV and Hessian penalty were 1.75 1.61 and 3.16 respectively, indicating that both TV and the proposed method is able to preserve edges. For CatPhan 600 CNR values of the proposed method were similar to those of TV and Hessian. Conclusion: The proposed method retains favorable properties of TV like preserving edges and also has the ability in better preserving gradual transition structure as Hessian does. All methods performs similarly in suppressing noise. This work was supported in part by National Natural Science Foundation of China (NNSFC) under

  14. Acidophilic adaptations in the structure of Acetobacter aceti N5-carboxyaminoimidazole ribonucleotide mutase (PurE).

    Science.gov (United States)

    Settembre, Ethan C; Chittuluru, Johnathan R; Mill, Christopher P; Kappock, T Joseph; Ealick, Steven E

    2004-10-01

    The crystal structure of Acetobacter aceti PurE was determined to a resolution of 1.55 A and is compared with the known structures of the class I PurEs from a mesophile, Escherichia coli, and a thermophile, Thermotoga maritima. Analyses of the general factors that increase protein stability are examined as potential explanations for the acid stability of A. aceti PurE. Increased inter-subunit hydrogen bonding and an increased number of arginine-containing salt bridges appear to account for the bulk of the increased acid stability. A chain of histidines linking two active sites is discussed in the context of the proton transfers catalyzed by the enzyme.

  15. Special Issue: Adaptive/Smart Structures and Multifunctional Materials with Application to Morphing Aircraft

    Directory of Open Access Journals (Sweden)

    Rafic Ajaj

    2014-12-01

    Full Text Available Recent advances in smart structures and multifunctional materials have facilitated many novel aerospace technologies such as morphing aircraft. A morphing aircraft, bio-inspired by natural fliers, has gained a lot of interest as a potential technology to meet the ambitious goals of the Advisory Council for Aeronautics Research in Europe (ACARE Vision 2020 and the FlightPath 2050 documents. A morphing aircraft continuously adjusts its wing geometry to enhance flight performance, control authority, and multi-mission capability.[...

  16. PHYSICO-CHEMICAL ASSESSMENT OF POMACE EXHAUSTED ...

    African Journals Online (AJOL)

    M’Sadak Y, Makhlouf M and El Amrouni S

    2016-05-01

    May 1, 2016 ... 2851. 6093. 3.1.2. Physico-chemical characterization. The physicochemical characteristics vary across different pomace oil extraction systems. (classic, press and continuous). Classical system. Table 2. Qualitative Characterization of pomace exhausted by the classical system. Parameters. Abbreviation.

  17. Physico-chemical Properties of Serendipity Berry ...

    African Journals Online (AJOL)

    This study evaluates the physico-chemical properties of serendipity berry. Physico-chemical properties of the serendipity berries were analyzed. The total number of berries in a bunch of fruit ranged from 45 to 98. This depends on the size of the bunch. The results revealed the dry matter, moisture, soluble solids and vitamin ...

  18. Physicochemical characteristics of Malaysian honeys influenced by ...

    African Journals Online (AJOL)

    Honey is a natural product that produced by honeybees or stingless bees. Consumers always found the best quality of honey by observing the physicochemical properties. However, storage time and temperature can affect the quality of honey. This study aimed to determine the physicochemical properties (moisture content, ...

  19. Phytochemical content, antioxidant capacity and physicochemical ...

    African Journals Online (AJOL)

    We investigated the antioxidant and physicochemical properties of pomegranate (Punica granatum cv. Bhagwa) fruit grown in three microclimates in South Africa. The physicochemical properties of fruit peel and arils differed among the growing locations, including weight and redness color of both peel and arils. Contents of ...

  20. Microbiological And Physicochemical Analyses Of Oil Contaminated ...

    African Journals Online (AJOL)

    Michael Horsfall

    The physicochemical properties of the soil samples analysed shows the pH ... Keywords: Oil contaminated soil, microbial isolates, mechanical workshops and physicochemical parameters. Pollution of the environment by petroleum ... strains capable of degrading Poly aromatic hydrocarbons have been isolated from soil and.

  1. The population genomic landscape of human genetic structure, admixture history and local adaptation in Peninsular Malaysia.

    Science.gov (United States)

    Deng, Lian; Hoh, Boon Peng; Lu, Dongsheng; Fu, Ruiqing; Phipps, Maude E; Li, Shilin; Nur-Shafawati, Ab Rajab; Hatin, Wan Isa; Ismail, Endom; Mokhtar, Siti Shuhada; Jin, Li; Zilfalil, Bin Alwi; Marshall, Christian R; Scherer, Stephen W; Al-Mulla, Fahd; Xu, Shuhua

    2014-09-01

    Peninsular Malaysia is a strategic region which might have played an important role in the initial peopling and subsequent human migrations in Asia. However, the genetic diversity and history of human populations--especially indigenous populations--inhabiting this area remain poorly understood. Here, we conducted a genome-wide study using over 900,000 single nucleotide polymorphisms (SNPs) in four major Malaysian ethnic groups (MEGs; Malay, Proto-Malay, Senoi and Negrito), and made comparisons of 17 world-wide populations. Our data revealed that Peninsular Malaysia has greater genetic diversity corresponding to its role as a contact zone of both early and recent human migrations in Asia. However, each single Orang Asli (indigenous) group was less diverse with a smaller effective population size (N(e)) than a European or an East Asian population, indicating a substantial isolation of some duration for these groups. All four MEGs were genetically more similar to Asian populations than to other continental groups, and the divergence time between MEGs and East Asian populations (12,000--6,000 years ago) was also much shorter than that between East Asians and Europeans. Thus, Malaysian Orang Asli groups, despite their significantly different features, may share a common origin with the other Asian groups. Nevertheless, we identified traces of recent gene flow from non-Asians to MEGs. Finally, natural selection signatures were detected in a batch of genes associated with immune response, human height, skin pigmentation, hair and facial morphology and blood pressure in MEGs. Notable examples include SYN3 which is associated with human height in all Orang Asli groups, a height-related gene (PNPT1) and two blood pressure-related genes (CDH13 and PAX5) in Negritos. We conclude that a long isolation period, subsequent gene flow and local adaptations have jointly shaped the genetic architectures of MEGs, and this study provides insight into the peopling and human migration

  2. Study of new structures adapted to gas-graphite and gas-heavy water reactors

    International Nuclear Information System (INIS)

    Martin, R.; Roche, R.

    1964-01-01

    The experience acquired as a result of the operation of the Marcoule reactors and of the construction and start-up of the E.D.F. reactors on the one hand, and the conclusions of research and tests carried out out-of-pile on the other hand, lead to a considerable change in the general design of reactors of the gas-graphite type. The main modifications envisaged are analysed in the paper. The adoption of an annular fuel element and of a down-current cooling will make it possible to increase considerably the specific power and the power output of each channel; as a result there will be a considerable reduction in the number of the channels and a corresponding increase in the size of the unit cell. The graphite stack will have to be adapted to there new conditions. For security reasons, the use of prestressed concrete for the construction of the reactor vessel is becoming more widespread; they could lead to the exchangers and the fuel-handling apparatus becoming integrated inside the vessel (the so-called 'attic' device). A full-size mode) of this attic has been built at Saclay with the participation of EURATOM; the operational results obtained are presented as well as a new original design for the control rods. As for as the gas-heavy-water system is concerned, the research is carried out on two points of design; the first, which retains the use of horizontal pressure tubes, takes into account the experience acquired during the construction of the EL 4 reactor of which it will constitute an extrapolation; the second, arising from the research carried out on the gas-graphite system, will use a pre-stressed concrete vessel for holding the pressure, the moderator being almost at the same pressure as the cooling fluid and the fuel being placed in vertical channels. The relative merits of these two variants are analysed in the present paper. (authors) [fr

  3. Bone inner structure suggests increasing aquatic adaptations in Desmostylia (Mammalia, Afrotheria.

    Directory of Open Access Journals (Sweden)

    Shoji Hayashi

    Full Text Available The paleoecology of desmostylians has been discussed controversially with a general consensus that desmostylians were aquatic or semi-aquatic to some extent. Bone microanatomy can be used as a powerful tool to infer habitat preference of extinct animals. However, bone microanatomical studies of desmostylians are extremely scarce.We analyzed the histology and microanatomy of several desmostylians using thin-sections and CT scans of ribs, humeri, femora and vertebrae. Comparisons with extant mammals allowed us to better understand the mode of life and evolutionary history of these taxa. Desmostylian ribs and long bones generally lack a medullary cavity. This trait has been interpreted as an aquatic adaptation among amniotes. Behemotops and Paleoparadoxia show osteosclerosis (i.e. increase in bone compactness, and Ashoroa pachyosteosclerosis (i.e. combined increase in bone volume and compactness. Conversely, Desmostylus differs from these desmostylians in displaying an osteoporotic-like pattern.In living taxa, bone mass increase provides hydrostatic buoyancy and body trim control suitable for poorly efficient swimmers, while wholly spongy bones are associated with hydrodynamic buoyancy control in active swimmers. Our study suggests that all desmostylians had achieved an essentially, if not exclusively, aquatic lifestyle. Behemotops, Paleoparadoxia and Ashoroa are interpreted as shallow water swimmers, either hovering slowly at a preferred depth, or walking on the bottom, and Desmostylus as a more active swimmer with a peculiar habitat and feeding strategy within Desmostylia. Therefore, desmostylians are, with cetaceans, the second mammal group showing a shift from bone mass increase to a spongy inner organization of bones in their evolutionary history.

  4. Structural and evolutionary adaptation of rhoptry kinases and pseudokinases, a family of coccidian virulence factors.

    Science.gov (United States)

    Talevich, Eric; Kannan, Natarajan

    2013-06-06

    The widespread protozoan parasite Toxoplasma gondii interferes with host cell functions by exporting the contents of a unique apical organelle, the rhoptry. Among the mix of secreted proteins are an expanded, lineage-specific family of protein kinases termed rhoptry kinases (ROPKs), several of which have been shown to be key virulence factors, including the pseudokinase ROP5. The extent and details of the diversification of this protein family are poorly understood. In this study, we comprehensively catalogued the ROPK family in the genomes of Toxoplasma gondii, Neospora caninum and Eimeria tenella, as well as portions of the unfinished genome of Sarcocystis neurona, and classified the identified genes into 42 distinct subfamilies. We systematically compared the rhoptry kinase protein sequences and structures to each other and to the broader superfamily of eukaryotic protein kinases to study the patterns of diversification and neofunctionalization in the ROPK family and its subfamilies. We identified three ROPK sub-clades of particular interest: those bearing a structurally conserved N-terminal extension to the kinase domain (NTE), an E. tenella-specific expansion, and a basal cluster including ROP35 and BPK1 that we term ROPKL. Structural analysis in light of the solved structures ROP2, ROP5, ROP8 and in comparison to typical eukaryotic protein kinases revealed ROPK-specific conservation patterns in two key regions of the kinase domain, surrounding a ROPK-conserved insert in the kinase hinge region and a disulfide bridge in the kinase substrate-binding lobe. We also examined conservation patterns specific to the NTE-bearing clade. We discuss the possible functional consequences of each. Our work sheds light on several important but previously unrecognized features shared among rhoptry kinases, as well as the essential differences between active and degenerate protein kinases. We identify the most distinctive ROPK-specific features conserved across both active

  5. Adapting prospective structural analysis to strengthen sustainable management and capacity building in community-based natural resource management contexts

    Directory of Open Access Journals (Sweden)

    María del Mar Delgado-Serrano

    2016-06-01

    Full Text Available Local communities collectively managing common pool resources can play an important role in sustainable management, but they often lack the skills and context-specific tools required for such management. The complex dynamics of social-ecological systems (SES, the need for management capacities, and communities' limited empowerment and participation skills present challenges for community-based natural resource management (CBNRM strategies. We analyzed the applicability of prospective structural analysis (PSA, a strategic foresight tool, to support decision making and to foster sustainable management and capacity building in CBNRM contexts and the modifications necessary to use the tool in such contexts. By testing PSA in three SES in Colombia, Mexico, and Argentina, we gathered information regarding the potential of this tool and its adaptation requirements. The results suggest that the tool can be adapted to these contexts and contribute to fostering sustainable management and capacity building. It helped identify the systems' dynamics, thus increasing the communities' knowledge about their SES and informing the decision-making process. Additionally, it drove a learning process that both fostered empowerment and built participation skills. The process demanded both time and effort, and required external monitoring and facilitation, but community members could be trained to master it. Thus, we suggest that the PSA technique has the potential to strengthen CBNRM and that other initiatives could use it, but they must be aware of these requirements.

  6. Multiple linear combination (MLC) regression tests for common variants adapted to linkage disequilibrium structure.

    Science.gov (United States)

    Yoo, Yun Joo; Sun, Lei; Poirier, Julia G; Paterson, Andrew D; Bull, Shelley B

    2017-02-01

    By jointly analyzing multiple variants within a gene, instead of one at a time, gene-based multiple regression can improve power, robustness, and interpretation in genetic association analysis. We investigate multiple linear combination (MLC) test statistics for analysis of common variants under realistic trait models with linkage disequilibrium (LD) based on HapMap Asian haplotypes. MLC is a directional test that exploits LD structure in a gene to construct clusters of closely correlated variants recoded such that the majority of pairwise correlations are positive. It combines variant effects within the same cluster linearly, and aggregates cluster-specific effects in a quadratic sum of squares and cross-products, producing a test statistic with reduced degrees of freedom (df) equal to the number of clusters. By simulation studies of 1000 genes from across the genome, we demonstrate that MLC is a well-powered and robust choice among existing methods across a broad range of gene structures. Compared to minimum P-value, variance-component, and principal-component methods, the mean power of MLC is never much lower than that of other methods, and can be higher, particularly with multiple causal variants. Moreover, the variation in gene-specific MLC test size and power across 1000 genes is less than that of other methods, suggesting it is a complementary approach for discovery in genome-wide analysis. The cluster construction of the MLC test statistics helps reveal within-gene LD structure, allowing interpretation of clustered variants as haplotypic effects, while multiple regression helps to distinguish direct and indirect associations. © 2016 The Authors Genetic Epidemiology Published by Wiley Periodicals, Inc.

  7. Structure-functional correlation using adaptive optics, OCT, and microperimetry in a case of occult macular dystrophy

    Directory of Open Access Journals (Sweden)

    Karlos Ítalo Viana

    Full Text Available ABSTRACT We report retinal functional and structural changes of a 40-year-old man diagnosed with occult macular dystrophy. Comprehensive ophthalmological evaluation was performed, followed by spectral-domain optical coherence tomography (SD-OC - Heidelberg and image acquisition using an adaptive optics (AO camera (RTX1, Imagine Eyes for photoreceptor density analysis. Functional tests included full-field ERG (ERG and multifocal electroretinography (mfERG (Diagnosys, LLC and microperimetry with scanning laser ophthalmoscope (SLO fixation controlled (MAIA, CenterVUE. OCT revealed a line of discontinuity corresponding to cone outer-segment photoreceptors associated with a loss of cone density, highlighted by a dark blue spot on the AO co ne-density map on the fovea in both eyes. Loss of central sensitivity was revealed using microperimetry; ERG was within the normal range, although the mfERG showed a reduced central response amplitude.

  8. "Adapted Linear Interaction Energy": A Structure-Based LIE Parametrization for Fast Prediction of Protein-Ligand Affinities.

    Science.gov (United States)

    Linder, Mats; Ranganathan, Anirudh; Brinck, Tore

    2013-02-12

    We present a structure-based parametrization of the Linear Interaction Energy (LIE) method and show that it allows for the prediction of absolute protein-ligand binding energies. We call the new model "Adapted" LIE (ALIE) because the α and β coefficients are defined by system-dependent descriptors and do therefore not require any empirical γ term. The best formulation attains a mean average deviation of 1.8 kcal/mol for a diverse test set and depends on only one fitted parameter. It is robust with respect to additional fitting and cross-validation. We compare this new approach with standard LIE by Åqvist and co-workers and the LIE + γSASA model (initially suggested by Jorgensen and co-workers) against in-house and external data sets and discuss their applicabilities.

  9. Small artery structure adapts to vasodilatation rather than to blood pressure during antihypertensive treatment

    DEFF Research Database (Denmark)

    Mathiassen, Ole N.; Buus, Niels H.; Larsen, Mogens L

    2007-01-01

    forearm resting vascular resistance (Rrest) and minimum vascular resistance (Rmin) as a measure of vascular structure. Two different groups of patients with essential hypertension were examined at baseline and after 6 months of antihypertensive treatment. In group A, 21 patients with never......-treated essential hypertension were treated by their general practitioners using a variety of drugs to allow an assessment of the drug-independent effects. In group B, 28 beta-blocker-treated patients were shifted to angiotensin II receptor blocker treatment (eprosartan) to allow vasodilatation with no change in BP...

  10. Resolution adapted finite element modeling of radio frequency interactions on conductive resonant structures in MRI.

    Science.gov (United States)

    Ruoff, Jürgen; Würslin, Christian; Graf, Hansjörg; Schick, Fritz

    2012-05-01

    Prediction of interactions between the radiofrequency electromagnetic field in magnetic resonance scanners and electrically conductive material surrounded by tissue plays an increasing role for magnetic resonance safety. Testing of conductive implants or instruments is usually performed by standardized experimental setups and temperature measurements at distinct geometrical points, which cannot always reflect worst-case situations. A finite element method based on Matlab (The Mathworks, Natick, MA) and the finite element method program Comsol Multiphysics (Stockholm, Sweden) with a spatially highly variable mesh size solving Maxwell's full-wave equations was applied for a comprehensive simulation of the complete geometrical arrangement of typical birdcage radiofrequency coils loaded with small conductive structures in a homogenous medium. Conductive implants like rods of variable length and closed and open ring structures, partly exhibiting electromagnetic resonance behavior, were modeled and evaluated regarding the distribution of the B(1)- and E-field, induced currents and specific absorption rates. Numerical simulations corresponded well with experiments using a spin-echo sequence for visualization of marked B(1)-field inhomogeneities. Even resonance effects in conductive rods and open rings with suitable geometry were depicted accurately. The proposed method has high potential for complementation or even replacement of common experimental magnetic resonance compatibility measurements. Copyright © 2011 Wiley Periodicals, Inc.

  11. Physicochemical evolution and positive selection of the gymnosperm matK proteins.

    Science.gov (United States)

    Hao, Da Cheng; Mu, Jun; Chen, Shi Lin; Xiao, Pei Gen

    2010-04-01

    It is not clear whether matK evolves under Darwinian selection. In this study, the gymnosperm Taxaceae, Cephalotaxaceae and Pinaceae were used to illustrate the physicochemical evolution, molecular adaptation and evolutionary dynamics of gene divergence in matKs. matK sequences were amplified from 27 Taxaceae and 12 Cephalotaxaceae species. matK sequences of 19 Pinaceae species were retrieved from GenBank. The phylogenetic tree was generated using conceptual-translated amino acid sequences. Selective influences were investigated using standard dN/dS ratio methods and more sensitive techniques investigating the amino acid property changes resulting from nonsynonymous replacements in a phylogenetic context. Analyses revealed the presence of positive selection in matKs (N-terminal region, RT domain and domain X) of Taxaceae and Pinaceae,and found positive destabilizing selection in N-terminal region and RT domain of Cephalotaxaceae matK. Moreover, various amino acid properties were found to be influenced by destabilizing positive selection. Amino acid sites relating to these properties and to different secondary structures were found and have the potential to affect group II intron maturase function. Despite the evolutionary constraint on the rapidly evolving matK, this protein evolves under positive selection in gymnosperm. Several regions of matK have experienced molecular adaptation which fine-tunes maturase performance.

  12. Mechanical adaptability of the Bouligand-type structure in natural dermal armour

    Science.gov (United States)

    Zimmermann, Elizabeth A.; Gludovatz, Bernd; Schaible, Eric; Dave, Neil K. N.; Yang, Wen; Meyers, Marc A.; Ritchie, Robert O.

    2013-10-01

    Arapaima gigas, a fresh water fish found in the Amazon Basin, resist predation by piranhas through the strength and toughness of their scales, which act as natural dermal armour. Arapaima scales consist of a hard, mineralized outer shell surrounding a more ductile core. This core region is composed of aligned mineralized collagen fibrils arranged in distinct lamellae. Here we show how the Bouligand-type (twisted plywood) arrangement of collagen fibril lamellae has a key role in developing their unique protective properties, by using in situ synchrotron small-angle X-ray scattering during mechanical tensile tests to observe deformation mechanisms in the fibrils. Specifically, the Bouligand-type structure allows the lamellae to reorient in response to the loading environment; remarkably, most lamellae reorient towards the tensile axis and deform in tension through stretching/sliding mechanisms, whereas other lamellae sympathetically rotate away from the tensile axis and compress, thereby enhancing the scale’s ductility and toughness to prevent fracture.

  13. Cardiac Adaptations (Structural and Functional to Regular Mountain Activities in Middle-aged Men

    Directory of Open Access Journals (Sweden)

    Abbas Saremi

    2017-09-01

    Full Text Available Abstract Background: Physical exercise is an important and effective part of comprehensive care of seniors, which declines aging progression. Because of the importance of physical activity in cardiovascular diseases prevention this study intends to investigate the comparision of structural and functional characterictics of the heart between middle- aged montaineer men and non-athlete peers. Materials and Methods: In this cross-sectional and descriptive–analytical study, 13 middle- aged montaineer (age: 54.5±2.0 y, body mass index: 25.59±2.4 kg/m2 who have continues mountain activities during previous 24 months for at least 2 sessions per week, each session lasted 120 minute, and 14 sedentary, healthy peers (age: 54.1±2.2 y, body mass index: 26.8±2.3 kg/m2 who were not currently experiencing any regular physical activity (at least 6 months, were selected. All subjects underwent standard two-dimensional and Doppler echocardiography at rest. Cardio respiratory fitness was assessed using Bruce test. T test was used to compare groups with α=0.05. Results: The results showed that mountain activities significantly increased left ventricular mass (p=0.03 and left-ventricular-end-diastolic-diameter (p=0.04. We also observed that systolic blood pressure (p=0.04, ejection fraction (p=0.05, stroke volume (p=0.03 and cardio respiratory fitness (p=0.03 were significantly improved by mountain climbing. In some of parameters such as shortening fraction, interventicular septum and left ventricular posterior wall there were no significant differences between groups (p>0.05. Conclusion: These results suggest that regular mountain sports activities can have beneficial effects on structural and functional characterictics of the heart in middle-aged men.

  14. Toxicity of Nanomaterials-Physicochemical Effects

    Directory of Open Access Journals (Sweden)

    A Rahi

    2015-02-01

    Full Text Available Nanomaterials involve the structures with at least one dimension of <100 nm. Recently, development in nanotechnology has led to the use of nanomaterials in many different fields. On the other hand, increasing use of nanomaterials has resulted in release of these materials to the environment. Therefore, before employing these materials in biological and living systems, they should be evaluated in terms of biocompatibility and distribution. Although the toxic effects of nanomaterials on living organisms, human health and the environment have been studied by some researchers, there are too much uncertainty regarding the effects and mechanisms of toxicity of nanomaterials. Therefore, understanding the toxicity effects of nanomaterials is highly desirable. Cellular uptake mechanisms and dispersion of nanomaterials in biological environments depend on their physicochemical properties. Therefore, knowledge of the unique characteristics of nanomaterials and the interactions of nanomaterials with biological systems, are important criteria for the safe use of nanomaterials. Properties of nanomaterials such as size, shape, aspect ratio, density, surface and structural defects and dissolving rate are the main causes of cytotoxicity and side effects of these materials in the body. Exposure to nanomaterials may cause a range of acute and chronic effects, including inflammation, exacerbation of asthma, metal fume fever, fibrosis, chronic inflammatory diseases and cancer. The present paper, reviews the previous studies aiming at the investigation of the relation between the physiochemical properties of nanomaterials and their toxicity.

  15. Evolution at 'Sutures' and 'Centers': Recombination Can Aid Adaptation of Spatially Structured Populations on Rugged Fitness Landscapes.

    Directory of Open Access Journals (Sweden)

    Jacob D Cooper

    2016-12-01

    Full Text Available Epistatic interactions among genes can give rise to rugged fitness landscapes, in which multiple "peaks" of high-fitness allele combinations are separated by "valleys" of low-fitness genotypes. How populations traverse rugged fitness landscapes is a long-standing question in evolutionary biology. Sexual reproduction may affect how a population moves within a rugged fitness landscape. Sex may generate new high-fitness genotypes by recombination, but it may also destroy high-fitness genotypes by shuffling the genes of a fit parent with a genetically distinct mate, creating low-fitness offspring. Either of these opposing aspects of sex require genotypic diversity in the population. Spatially structured populations may harbor more diversity than well-mixed populations, potentially amplifying both positive and negative effects of sex. On the other hand, spatial structure leads to clumping in which mating is more likely to occur between like types, diminishing the effects of recombination. In this study, we use computer simulations to investigate the combined effects of recombination and spatial structure on adaptation in rugged fitness landscapes. We find that spatially restricted mating and offspring dispersal may allow multiple genotypes inhabiting suboptimal peaks to coexist, and recombination at the "sutures" between the clusters of these genotypes can create genetically novel offspring. Sometimes such an offspring genotype inhabits a new peak on the fitness landscape. In such a case, spatially restricted mating allows this fledgling subpopulation to avoid recombination with distinct genotypes, as mates are more likely to be the same genotype. Such population "centers" can allow nascent peaks to establish despite recombination. Spatial structure may therefore allow an evolving population to enjoy the creative side of sexual recombination while avoiding its destructive side.

  16. High-altitude adaptations in vertebrate hemoglobins

    DEFF Research Database (Denmark)

    Weber, Roy E.

    2007-01-01

    ’s intrinsic O2-affinity and its allosteric interaction with cellular effectors (organic phosphates, protons and chloride). Whereas short-term altitudinal adaptations predominantly involve adjustments in allosteric interactions, long-term, genetically-coded adaptations typically involve changes....... Molecular heterogeneity (multiple isoHbs with differentiated oxygenation properties) can further broaden the range of physico-chemical conditions where Hb functions under altitudinal hypoxia. This treatise reviews the molecular and cellular mechanisms that adapt haemoglobin-oxygen affinities in mammals...

  17. Active membrane having uniform physico-chemically functionalized ion channels

    Science.gov (United States)

    Gerald, II, Rex E; Ruscic, Katarina J; Sears, Devin N; Smith, Luis J; Klingler, Robert J; Rathke, Jerome W

    2012-09-24

    The present invention relates to a physicochemically-active porous membrane for electrochemical cells that purports dual functions: an electronic insulator (separator) and a unidirectional ion-transporter (electrolyte). The electrochemical cell membrane is activated for the transport of ions by contiguous ion coordination sites on the interior two-dimensional surfaces of the trans-membrane unidirectional pores. One dimension of the pore surface has a macroscopic length (1 nm-1000 .mu.m) and is directed parallel to the direction of an electric field, which is produced between the cathode and the anode electrodes of an electrochemical cell. The membrane material is designed to have physicochemical interaction with ions. Control of the extent of the interactions between the ions and the interior pore walls of the membrane and other materials, chemicals, or structures contained within the pores provides adjustability of the ionic conductivity of the membrane.

  18. Inferring long-distance dispersal modes in American amphitropically disjunct species through adaptive dispersal structures.

    Science.gov (United States)

    Schenk, John J; Saunders, Kelsey

    2017-11-22

    A repeated pattern of American amphitropical disjunct species or sister species distributed on either side of the equator has long-fascinated botanists, but the modes of these disjunctions remain untested. We evaluated diaspore morphology to generate hypotheses on probable dispersal mechanisms. The sizes and structures of diaspores, habit, habitat, distribution, and dispersal units were collected for 108 species from literature searches and herbarium specimens. Variation was evaluated with summary statistics, χ 2 tests with Monte Carlo simulations, ANOVAs, and the nonparametric Mann-Whitney test. Seeds were the dispersing diaspore in 38.0% of the species, 45.4 were dispersed as fruits, and the remaining were dispersed as infructescences or spores. Diaspores were epizoochorous (52.8%), anemochorous (20.4%), achorous (15.7%), endozoochorous (8.3%), and hydrochorous (2.8%). Epizoochory was significantly greater than expected. Zoochory occurred more frequently than expected when considering achorous diaspores as animal-dispersed. Most species were associated with wetland, woodland, and grassland habitats. An ANOVA revealed that diaspores associated with hydrochory were larger and anemochory was smaller; all other syndromes were not significantly different. Botanists have long-held the assumption that bird migrations are responsible for amphitropical disjunctions. Our results support this hypothesis, with the majority of these events occurring by external attachment of small fruits. However, our results also indicate that anemochory might play a greater role in producing amphitropical distributions than previously thought and at a greater rate than endozoochory or hydrochory. © 2017 Botanical Society of America.

  19. Three-dimensional Imaging Reveals New Compartments and Structural Adaptations in Odontoblasts.

    Science.gov (United States)

    Khatibi Shahidi, M; Krivanek, J; Kaukua, N; Ernfors, P; Hladik, L; Kostal, V; Masich, S; Hampl, A; Chubanov, V; Gudermann, T; Romanov, R A; Harkany, T; Adameyko, I; Fried, K

    2015-07-01

    In organized tissues, the precise geometry and the overall shape are critical for the specialized functions that the cells carry out. Odontoblasts are major matrix-producing cells of the tooth and have also been suggested to participate in sensory transmission. However, refined morphologic data on these important cells are limited, which hampers the analysis and understanding of their cellular functions. We took advantage of fluorescent color-coding genetic tracing to visualize and reconstruct in 3 dimensions single odontoblasts, pulp cells, and their assemblages. Our results show distinct structural features and compartments of odontoblasts at different stages of maturation, with regard to overall cellular shape, formation of the main process, orientation, and matrix deposition. We demonstrate previously unanticipated contacts between the processes of pulp cells and odontoblasts. All reported data are related to mouse incisor tooth. We also show that odontoblasts express TRPM5 and Piezo2 ion channels. Piezo2 is expressed ubiquitously, while TRPM5 is asymmetrically distributed with distinct localization to regions proximal to and within odontoblast processes. © International & American Associations for Dental Research 2015.

  20. Ambiguous Adaptation

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Lyngsie, Jacob

    and reciprocal adaptation of informal governance structure create ambiguity in situations of contingencies, which, subsequently, increases the likelihood of premature relationship termination. Using a large sample of exchange relationships in the global service provider industry, we find support for a hypothesis...

  1. The Double ABCX Model of Family Stress and Adaptation: An Empirical Test by Analysis of Structural Equations with Latent Variables.

    Science.gov (United States)

    Lavee, Yoav; And Others

    1985-01-01

    Examined relationships among major variables of the Double ABCX model of family stress and adaptation using data on Army families' adaptation to the crisis of relocation overseas. Results support the notion of pile-up of demands. Family system resources and social support are both found to facilitate adaptation. (Author/BL)

  2. Population genomic structure and adaptation in the zoonotic malaria parasite Plasmodium knowlesi

    KAUST Repository

    Assefa, Samuel

    2015-10-06

    Malaria cases caused by the zoonotic parasite Plasmodium knowlesi are being increasingly reported throughout Southeast Asia and in travelers returning from the region. To test for evidence of signatures of selection or unusual population structure in this parasite, we surveyed genome sequence diversity in 48 clinical isolates recently sampled from Malaysian Borneo and in five lines maintained in laboratory rhesus macaques after isolation in the 1960s from Peninsular Malaysia and the Philippines. Overall genomewide nucleotide diversity (π = 6.03 × 10) was much higher than has been seen in worldwide samples of either of the major endemic malaria parasite species Plasmodium falciparum and Plasmodium vivax. A remarkable substructure is revealed within P. knowlesi, consisting of two major sympatric clusters of the clinical isolates and a third cluster comprising the laboratory isolates. There was deep differentiation between the two clusters of clinical isolates [mean genomewide fixation index (F) = 0.21, with 9,293 SNPs having fixed differences of F = 1.0]. This differentiation showed marked heterogeneity across the genome, with mean F values of different chromosomes ranging from 0.08 to 0.34 and with further significant variation across regions within several chromosomes. Analysis of the largest cluster (cluster 1, 38 isolates) indicated long-term population growth, with negatively skewed allele frequency distributions (genomewide average Tajima\\'s D = -1.35). Against this background there was evidence of balancing selection on particular genes, including the circumsporozoite protein (csp) gene, which had the top Tajima\\'s D value (1.57), and scans of haplotype homozygosity implicate several genomic regions as being under recent positive selection.

  3. The Diversity, Structure, and Function of Heritable Adaptive Immunity Sequences in the Aedes aegypti Genome.

    Science.gov (United States)

    Whitfield, Zachary J; Dolan, Patrick T; Kunitomi, Mark; Tassetto, Michel; Seetin, Matthew G; Oh, Steve; Heiner, Cheryl; Paxinos, Ellen; Andino, Raul

    2017-11-20

    The Aedes aegypti mosquito transmits arboviruses, including dengue, chikungunya, and Zika virus. Understanding the mechanisms underlying mosquito immunity could provide new tools to control arbovirus spread. Insects exploit two different RNAi pathways to combat viral and transposon infection: short interfering RNAs (siRNAs) and PIWI-interacting RNAs (piRNAs) [1, 2]. Endogenous viral elements (EVEs) are sequences from non-retroviral viruses that are inserted into the mosquito genome and can act as templates for the production of piRNAs [3, 4]. EVEs therefore represent a record of past infections and a reservoir of potential immune memory [5]. The large-scale organization of EVEs has been difficult to resolve with short-read sequencing because they tend to integrate into repetitive regions of the genome. To define the diversity, organization, and function of EVEs, we took advantage of the contiguity associated with long-read sequencing to generate a high-quality assembly of the Ae. aegypti-derived Aag2 cell line genome, an important and widely used model system. We show EVEs are acquired through recombination with specific classes of long terminal repeat (LTR) retrotransposons and organize into large loci (>50 kbp) characterized by high LTR density. These EVE-containing loci have increased density of piRNAs compared to similar regions without EVEs. Furthermore, we detected EVE-derived piRNAs consistent with a targeted processing of persistently infecting virus genomes. We propose that comparisons of EVEs across mosquito populations may explain differences in vector competence, and further study of the structure and function of these elements in the genome of mosquitoes may lead to epidemiological interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Structural adaptations of two sympatric epiphytic orchids (Orchidaceae to a cloudy forest environment in rocky outcrops of Southeast Brazil

    Directory of Open Access Journals (Sweden)

    Ana Sílvia Franco Pinheiro

    2013-09-01

    Full Text Available The survival of plants in epiphytic environments depends on vegetative adaptations capable to defraud different stresses. Based on the structural diversity of the Orchidaceae, the current study has the objective of relating the anatomical structure of Dichaea cogniauxiana and Epidendrum secundum with the distinct environments where they live. It was expected that, despite structural similarities as strategies for resource acquisition, some peculiar variations related to the distinct light microenvironments (inside or in the edge of the nebular forest, near to “campo rupestre” area might be found. Leaves and roots of both species were collected in a nebular forest located at a “campo rupestre” area at Serra da Piedade, Brazil, in January and February 2005. D. cogniauxiana is adhered to trunks, in sites with high atmospheric humidity and shaded, while E. secundum is located at the edge of the nebular forest, in more luminous sites. The leaves of E. secundum had thicker cuticle and higher number of stomata per area than those of D. cogniauxiana, characteristics coherent with their distinct pattern of exhibition to sun light. The suprastomatic chambers formed by the thicker cuticle may function as a barrier of resistance to water evaporation. The succulence of the leaves of E. secundum propitiates organic acids storage at night, and the storage of starch may be involved in PEP-carboxylase metabolism, both propitiating CAM mechanism. Roots with larger number of cell layers of the velamen, and specialized thick walled cortical cells (both in E. secundum help water absorption and indicate better adaptation to an environment with intense solar radiation and a probable higher water deficit. The remarkable cell wall thickening of E. secundum exodermis can confer more efficient protection against the excess of transpiration at the border of the nebular forest. On the other hand, besides D. cogniauxiana be epiphyte, it is in a low position - in a

  5. An application of neural network for Structural Health Monitoring of an adaptive wing with an array of FBG sensors

    International Nuclear Information System (INIS)

    Mieloszyk, Magdalena; Skarbek, Lukasz; Ostachowicz, Wieslaw; Krawczuk, Marek

    2011-01-01

    This paper presents an application of neural networks to determinate the level of activation of shape memory alloy actuators of an adaptive wing. In this concept the shape of the wing can be controlled and altered thanks to the wing design and the use of integrated shape memory alloy actuators. The wing is assumed as assembled from a number of wing sections that relative positions can be controlled independently by thermal activation of shape memory actuators. The investigated wing is employed with an array of Fibre Bragg Grating sensors. The Fibre Bragg Grating sensors with combination of a neural network have been used to Structural Health Monitoring of the wing condition. The FBG sensors are a great tool to control the condition of composite structures due to their immunity to electromagnetic fields as well as their small size and weight. They can be mounted onto the surface or embedded into the wing composite material without any significant influence on the wing strength. The paper concentrates on analysis of the determination of the twisting moment produced by an activated shape memory alloy actuator. This has been analysed both numerically using the finite element method by a commercial code ABAQUS (registered) and experimentally using Fibre Bragg Grating sensor measurements. The results of the analysis have been then used by a neural network to determine twisting moments produced by each shape memory alloy actuator.

  6. Temperature structure of the intracluster medium from smoothed-particle hydrodynamics and adaptive-mesh refinement simulations

    Energy Technology Data Exchange (ETDEWEB)

    Rasia, Elena [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109 (United States); Lau, Erwin T.; Nagai, Daisuke; Avestruz, Camille [Department of Physics, Yale University, New Haven, CT 06520 (United States); Borgani, Stefano [Dipartimento di Fisica dell' Università di Trieste, Sezione di Astronomia, via Tiepolo 11, I-34131 Trieste (Italy); Dolag, Klaus [University Observatory Munich, Scheiner-Str. 1, D-81679 Munich (Germany); Granato, Gian Luigi; Murante, Giuseppe; Ragone-Figueroa, Cinthia [INAF, Osservatorio Astronomico di Trieste, via Tiepolo 11, I-34131, Trieste (Italy); Mazzotta, Pasquale [Dipartimento di Fisica, Università di Roma Tor Vergata, via della Ricerca Scientifica, I-00133, Roma (Italy); Nelson, Kaylea, E-mail: rasia@umich.edu [Department of Astronomy, Yale University, New Haven, CT 06520 (United States)

    2014-08-20

    Analyses of cosmological hydrodynamic simulations of galaxy clusters suggest that X-ray masses can be underestimated by 10%-30%. The largest bias originates from both violation of hydrostatic equilibrium (HE) and an additional temperature bias caused by inhomogeneities in the X-ray-emitting intracluster medium (ICM). To elucidate this large dispersion among theoretical predictions, we evaluate the degree of temperature structures in cluster sets simulated either with smoothed-particle hydrodynamics (SPH) or adaptive-mesh refinement (AMR) codes. We find that the SPH simulations produce larger temperature variations connected to the persistence of both substructures and their stripped cold gas. This difference is more evident in nonradiative simulations, whereas it is reduced in the presence of radiative cooling. We also find that the temperature variation in radiative cluster simulations is generally in agreement with that observed in the central regions of clusters. Around R {sub 500} the temperature inhomogeneities of the SPH simulations can generate twice the typical HE mass bias of the AMR sample. We emphasize that a detailed understanding of the physical processes responsible for the complex thermal structure in ICM requires improved resolution and high-sensitivity observations in order to extend the analysis to higher temperature systems and larger cluster-centric radii.

  7. Quantitative structure-activity relationship study on BTK inhibitors by modified multivariate adaptive regression spline and CoMSIA methods.

    Science.gov (United States)

    Xu, A; Zhang, Y; Ran, T; Liu, H; Lu, S; Xu, J; Xiong, X; Jiang, Y; Lu, T; Chen, Y

    2015-01-01

    Bruton's tyrosine kinase (BTK) plays a crucial role in B-cell activation and development, and has emerged as a new molecular target for the treatment of autoimmune diseases and B-cell malignancies. In this study, two- and three-dimensional quantitative structure-activity relationship (2D and 3D-QSAR) analyses were performed on a series of pyridine and pyrimidine-based BTK inhibitors by means of genetic algorithm optimized multivariate adaptive regression spline (GA-MARS) and comparative molecular similarity index analysis (CoMSIA) methods. Here, we propose a modified MARS algorithm to develop 2D-QSAR models. The top ranked models showed satisfactory statistical results (2D-QSAR: Q(2) = 0.884, r(2) = 0.929, r(2)pred = 0.878; 3D-QSAR: q(2) = 0.616, r(2) = 0.987, r(2)pred = 0.905). Key descriptors selected by 2D-QSAR were in good agreement with the conclusions of 3D-QSAR, and the 3D-CoMSIA contour maps facilitated interpretation of the structure-activity relationship. A new molecular database was generated by molecular fragment replacement (MFR) and further evaluated with GA-MARS and CoMSIA prediction. Twenty-five pyridine and pyrimidine derivatives as novel potential BTK inhibitors were finally selected for further study. These results also demonstrated that our method can be a very efficient tool for the discovery of novel potent BTK inhibitors.

  8. Implanted In-Body Tissue-Engineered Heart Valve Can Adapt the Histological Structure to the Environment.

    Science.gov (United States)

    Takewa, Yoshiaki; Sumikura, Hirohito; Kishimoto, Satoru; Naito, Noritsugu; Iizuka, Kei; Akiyama, Daichi; Iwai, Ryosuke; Tatsumi, Eisuke; Nakayama, Yasuhide

    2018-03-05

    Tissue-engineered heart valves (TEHVs) are expected to be viable grafts. However, it is unknown whether they transit their histological structure after implantation. We developed a novel autologous TEHV (named stent biovalve) for transcatheter implantation, using in-body tissue engineering based on a tissue encapsulation phenomenon. In this study, a time-course histological transition of implanted biovalves was investigated in goats. Three types of stent biovalves were prepared by 2 month embedding of plastic molds mounted with metallic stents, in the subcutaneous spaces. After extracting the molds with tissue and removing the molds only, stent biovalves were constituted entirely from the connective tissues. Stent biovalves were implanted in the aortic or pulmonary valve position of other goats with transcatheter technique. In each animal, the stent biovalve was explanted at 1 month step (from 1 to 6 months) or as long as possible. Total 12 goats (five for aortic and seven for pulmonary) were successfully implanted. The maximum duration became 19 months as a result. Even then the leaflets of the biovalves kept their shape and elasticity, and neither calcification nor thrombi were observed in any cases and duration. Histology showed the recipients' cells covering the laminar surface of the leaflets like the endothelium even after 1 month. The cells have also migrated in the leaflets gradually and finally constructed characteristic 3 layered tissues like native leaflets. Implanted stent biovalves can adapt their histological structure to the environment. They have a potential as viable grafts keeping better function and biocompatibility.

  9. The masticatory system under varying functional load. Part 1: Structural adaptation of rabbit jaw muscles to reduced masticatory load.

    Science.gov (United States)

    Vreeke, Marloes; Langenbach, Geerling E J; Korfage, Joannes A M; Zentner, Andrej; Grünheid, Thorsten

    2011-08-01

    Skeletal muscle fibres can change their myosin heavy-chain (MyHC) isoform and cross-sectional area, which determine their contraction velocity and maximum force generation, respectively, to adapt to varying functional loads. In general, reduced muscle activity induces transition towards faster fibres and a decrease in fibre cross-sectional area. In order to investigate the effect of a reduction in masticatory load on three functionally different jaw muscles, the MyHC composition and the corresponding cross-sectional area of fibres were determined in the superficial masseter, superficial temporalis, and digastric muscles of male juvenile New Zealand White rabbits that had been raised on a soft diet (n=8) from 8 to 20 weeks of age and in those of normal diet controls (n=8). Differences between groups were tested for statistical significance using a Mann-Whitney rank sum test. The proportion and cross-sectional area of fibres co-expressing MyHC-I and MyHC-cardiac alpha were significantly smaller in the masseter muscles of the animals that had been fed soft food than in those of the controls. In contrast, the proportions and cross-sectional areas of the various fibre types in the temporalis and digastric muscles did not differ significantly between the groups. The results suggest that reducing the masticatory load during development affects the contraction velocity and maximum force generation of the jaw-closing muscles that are primarily responsible for force generation during chewing. These muscles adapt structurally to the reduced functional load with changes in the MyHC composition and cross-sectional area mainly within their slow fibre compartment.

  10. Left ventricular mechanics in humans with high aerobic fitness: adaptation independent of structural remodelling, arterial haemodynamics and heart rate

    Science.gov (United States)

    Stöhr, Eric J; McDonnell, Barry; Thompson, Jane; Stone, Keeron; Bull, Tom; Houston, Rory; Cockcroft, John; Shave, Rob

    2012-01-01

    Individuals with high aerobic fitness have lower systolic left ventricular strain, rotation and twist (‘left ventricular (LV) mechanics’) at rest, suggesting a beneficial reduction in LV myofibre stress and more efficient systolic function. However, the mechanisms responsible for this functional adaptation are not known and the influence of aerobic fitness on LV mechanics during dynamic exercise has never been studied. We assessed LV mechanics, LV wall thickness and dimensions, central augmentation index (AIx), aortic pulse wave velocity (aPWV), blood pressure and heart rate in 28 males (age: 21 ± 2 years SD) with a consistent physical activity level (no change >6 months). Individuals were examined at rest and during exercise (40% peak exercise capacity) and separated post hoc into a moderate and high aerobic fitness group (: 49 ± 5 and 63 ± 7 ml kg−1 min−1, respectively, P 0.05). However, for the same AIx, the high group had significantly lower LV apical rotation (P = 0.002) and LV twist (P = 0.003) while basal rotation and strain indices did not differ between groups (P > 0.05). We conclude that young males with high aerobic fitness have lower LV apical rotation at rest and during submaximal exercise that can occur without changes in gross LV structure, arterial haemodynamics or heart rate. The findings suggest a previously unknown type of physiological adaptation of the left ventricle that may have important implications for exercise training in older individuals and patient populations in which exercise training has previously failed to show clear benefits for LV function. PMID:22431336

  11. Ring-Shaped Seismicity Structures in the Areas of Sarez and Nurek Water Reservoirs (Tajikistan): Lithosphere Adaptation to Additional Loading

    Science.gov (United States)

    Kopnichev, Yu. F.; Sokolova, I. N.

    2017-12-01

    Seismicity characteristics in the areas of Sarez Lake and the Nurek water reservoir are studied. Ring-shaped seismicity structures in two depth ranges (0-33 and 34-70 km) formed prior to the Pamir earthquake of December 7, 2015 ( M w = 7.2). Seismicity rings cross each other near the Usoi Dam, which formed after the strong earthquake in 1911 and led to the formation of Sarez Lake, and near the epicenter of the Pamir earthquake. In addition, three out of the four strongest events ( M ≥ 6.0) recorded in the Pamir region at depths of more than 70 km since 1950 have occurred near Sarez Lake. An aggregate of the data allows us to conclude that the Pamir earthquake, despite its very large energy, refers to events related to induced seismicity. Ring-shaped seismicity structures in two depth ranges also formed in the Nurek water reservoir area. It is supposed that the formation of ring-shaped structures is related to the self-organization processes of a geological system, which result in the ascent of deep-seated fluids. In this respect, the lithosphere is gradually adapting to the additional load related to the filling of the water reservoir. The difference between Nurek Dam (and many other hydroelectric power stations as well) and Usoi Dam is the permanent vibration in the former case due to water falling from a height of more than 200 m. Such an effect can lead to gradual stress dissipation, resulting in the occurrence of much weaker events when compared to the Pamir earthquake of December 7, 2015, in the areas of artificial water reservoirs.

  12. Impact of pressure on physicochemical properties of starch dispersions

    KAUST Repository

    Yang, Zhi

    2016-09-02

    High hydrostatic pressure (HHP) can be employed as a non-thermal sterilization technique in the food industry while inducing structure and physicochemical changes of the food macromolecules like starch. The effect of HHP on starch depends on various factors including starch type and concentration, pressurization temperature, time, and suspending media. In this review, we summarize the influence of HHP on the structure, gelatinization, retrogradation, and modification of starches from different botanical origins. Suggestions for future research are provided to better understand the mechanism of HHP on starch, and on how HHP can be used in the starch industry. © 2016 Elsevier Ltd.

  13. Strategic Adaptation

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    2015-01-01

    concepts of strategic renewal, dynamic managerial capabilities, dynamic capabilities, and strategic response capabilities are discussed and contextualized against strategic responsiveness. The insights derived from this article are used to outline the contours of a dynamic process of strategic adaptation......This article provides an overview of theoretical contributions that have influenced the discourse around strategic adaptation including contingency perspectives, strategic fit reasoning, decision structure, information processing, corporate entrepreneurship, and strategy process. The related....... This model incorporates elements of central strategizing, autonomous entrepreneurial behavior, interactive information processing, and open communication systems that enhance the organization's ability to observe exogenous changes and respond effectively to them....

  14. Physico-chemical composition and radicalscavenging activity ...

    African Journals Online (AJOL)

    Physico-chemical composition and radicalscavenging activity evaluation of the extracts of Aristolochia albida Duch. (Aristolochiaceae) of Benin. Félix F.D. Guinnin, Isabelle T. Sacramento, Jean-Marc Ategbo, Cocou Dossa Pascal Agbangnan ...

  15. Physicochemically functional ultrathin films by interfacial polymerization

    Science.gov (United States)

    Lonsdale, Harold K.; Babcock, Walter C.; Friensen, Dwayne T.; Smith, Kelly L.; Johnson, Bruce M.; Wamser, Carl C.

    1990-01-01

    Interfacially-polymerized ultrathin films containing physicochemically functional groups are disclosed, both with and without supports. Various applications are disclsoed, including membrane electrodes, selective membranes and sorbents, biocompatible materials, targeted drug delivery, and narrow band optical absorbers.

  16. Evaluation of some physicochemical parameters and benthic ...

    African Journals Online (AJOL)

    Evaluation of some physicochemical parameters and benthic macroinvertebrates of Ikere Gorge Reservoir in Oyo State, Nigeria. ... Reservoir is relatively under stress due to dominance of indicators of pollution. Keywords: Anthropogenic activities, Bioindicator, Ikere Gorge Reservoir, Melanoides tuberculata, Water quality.

  17. Pharmacognostic and physicochemical evaluation of homoeopathic drug: Erigeron canadensis L.

    Directory of Open Access Journals (Sweden)

    Padma Rao Pogaku

    2017-01-01

    Full Text Available Background: Erigeron canadensis L. is an erect annual herb belonging to the family Asteraceae. Aerial parts are used in Homoeopathy for bruises, cough, dysuria, gonorrhea, haemorrhages, haemorrhoids, spermatorrhea, and wounds. Objective: The pharmacognostic and physicochemical studies have been carried out to facilitate the use of correct species and lay down standards of raw drug materials. Materials and Methods: Pharmacognostic studies of the leaf and stem of authentic samples of E. canadensis L. have been carried out. Physicochemical parameters of the raw drug include extractive values, ash value, and formulation; besides weight per mL, total solids, and alcohol content, high-performance thin layer chromatography (HPTLC and ultraviolet (UV studies are given. Results: Epidermal cells often possess crystals of calcium oxalate. Stomata are anomocytic, anisocytic, and tetracytic types. Trichomes are uniseriate and conical in structure. The mid vein in transection is flat on adaxial and is ribbed toward abaxial, with a secretory cavity beneath the central vascular bundle. Stem in transection is round. The vascular tissue is made of several vascular bundles in a ring. Crystals of calcium oxalate occur in the epidermis, cortex, and pith of stem. In mature stem, secondary xylem is well developed with a reduced phloem. The determined physicochemical data, namely, extractive values, ash values, and preparation of for raw drug and weight per mL, total solids, and alcohol content besides UV and HPTLC profile for finished product are provided. Conclusions: The presented morphoanatomical features along with powder microscopic and organoleptic characters and physicochemical data are diagnostic to establish the standards for ensuring quality and purity of the drug.

  18. Detection of Differential Item Functioning on the Kirton Adaption-Innovation Inventory Using Multiple-Group Mean and Covariance Structure Analyses.

    Science.gov (United States)

    Chan, David

    2000-01-01

    Demonstrates how the mean and covariance structure analysis model of D. Sorbom (1974) can be used to detect uniform and nonuniform differential item functioning (DIF) on polytomous ordered response items assumed to approximate a continuous scale. Uses results from 773 civil service employees administered the Kirton Adaption-Innovation Inventory…

  19. Adaptation and Latent Structure of the Swahili Version of Beck Depression Inventory-II in a Low Literacy Population in the Context of HIV

    NARCIS (Netherlands)

    Abubakar, A.; Kalu, Raphael Birya; Katana, Khamis; Kabunda, Beatrice; Hassan, Amin S.; Newton, Charles R.; Van de Vijver, Fons

    2016-01-01

    Objective We set out to adapt the Beck Depression Inventory (BDI)-II in Kenya and examine its factorial structure. Methods In the first phase we carried out in-depth interviews involving 29 adult members of the community to elicit their understanding of depression and identify aspects of the BDI-II

  20. Adaptation of soil microbial community structure and function to chronic metal contamination at an abandoned Pb-Zn mine.

    Science.gov (United States)

    Epelde, Lur; Lanzén, Anders; Blanco, Fernando; Urich, Tim; Garbisu, Carlos

    2015-01-01

    Toxicity of metals released from mine tailings may cause severe damage to ecosystems. A diversity of microorganisms, however, have successfully adapted to such sites. In this study, our objective was to advance the understanding of the indigenous microbial communities of mining-impacted soils. To this end, a metatranscriptomic approach was used to study a heavily metal-contaminated site along a metal concentration gradient (up to 3220 000 and 97 000 mg kg(-1) of Cd, Pb and Zn, respectively) resulting from previous mining. Metal concentration, soil pH and amount of clay were the most important factors determining the structure of soil microbial communities. Interestingly, evenness of the microbial communities, but not its richness, increased with contamination level. Taxa with high metabolic plasticity like Ktedonobacteria and Chloroflexi were found with higher relative abundance in more contaminated samples. However, several taxa belonging to the phyla Actinobacteria and Acidobacteria followed opposite trends in relation to metal pollution. Besides, functional transcripts related to transposition or transfer of genetic material and membrane transport, potentially involved in metal resistance mechanisms, had a higher expression in more contaminated samples. Our results provide an insight into microbial communities in long-term metal-contaminated environments and how they contrast to nearby sites with lower contamination. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. A new strategy for exploring the hierarchical structure of cancers by adaptively partitioning functional modules from gene expression network.

    Science.gov (United States)

    Xu, Junmei; Jing, Runyu; Liu, Yuan; Dong, Yongcheng; Wen, Zhining; Li, Menglong

    2016-06-28

    The interactions among the genes within a disease are helpful for better understanding the hierarchical structure of the complex biological system of it. Most of the current methodologies need the information of known interactions between genes or proteins to create the network connections. However, these methods meet the limitations in clinical cancer researches because different cancers not only share the common interactions among the genes but also own their specific interactions distinguished from each other. Moreover, it is still difficult to decide the boundaries of the sub-networks. Therefore, we proposed a strategy to construct a gene network by using the sparse inverse covariance matrix of gene expression data, and divide it into a series of functional modules by an adaptive partition algorithm. The strategy was validated by using the microarray data of three cancers and the RNA-sequencing data of glioblastoma. The different modules in the network exhibited specific functions in cancers progression. Moreover, based on the gene expression profiles in the modules, the risk of death was well predicted in the clustering analysis and the binary classification, indicating that our strategy can be benefit for investigating the cancer mechanisms and promoting the clinical applications of network-based methodologies in cancer researches.

  2. EDITORIAL: Adaptive and active materials: Selected papers from the ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 11) (Scottsdale, AZ, USA, 18-21 September 2011) Adaptive and active materials: Selected papers from the ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 11) (Scottsdale, AZ, USA, 18-21 September 2011)

    Science.gov (United States)

    Brei, Diann

    2012-09-01

    The fourth annual meeting of the ASME/AIAA Smart Materials, Adaptive Structures and Intelligent Systems Conference (SMASIS) took place in sunny Scottsdale, Arizona. Each year we strive to grow and offer new experiences. This year we held a special Guest Symposium on Sustainability along with two focused topic tracks on energy harvesting and active composites to encourage cross-fertilization between these important fields and our community. This cross-disciplinary emphasis was reflected in keynote talks by Dr Wayne Brown, President and founder of Dynalloy, Inc., 'Cross-Discipline Sharing'; Dr Brad Allenby, Arizona State University, 'You Want the Future? You can't Handle the Future!'; and Professor Aditi Chattopadhyay, Arizona State University, 'A Multidisciplinary Approach to Structural Health Monitoring and Prognosis'. SMASIS continues to grow our community through both social and technical interchange. The conference location, the exotic Firesky Resort and Spa, exemplified the theme of our Guest Symposium on Sustainability, being the only Green Seal certified resort in Arizona, and highlighting four elements thought to represent all that exist: fire, water, earth and air. Several special events were held around this theme including the night at the oasis reception sponsored by General Motors, sustainability bingo, smart trivia and student networking lunches, and an Arizona pow-wow with a spectacular Indian hoop dance. Our student and young professional development continues to grow strong with best paper and hardware competitions, scavenger student outing and games night. We are very proud that our students and young professionals are always seeking out ways to give back to the community, including organizing outreach to local high school talent. We thank all of our sponsors who made these special events possible. We hope that these social events provided participants with the opportunity to expand their own personal community and broaden their horizons. Our

  3. Facilitating peer based learning through summative assessment - An adaptation of the Objective Structured Clinical Assessment tool for the blended learning environment.

    Science.gov (United States)

    Wikander, Lolita; Bouchoucha, Stéphane L

    2018-01-01

    Adapting a course from face to face to blended delivery necessitates that assessments are modified accordingly. In Australia the Objective Structured Clinical Assessment tool, as a derivative from the Objective Structured Clinical Examination, has been used in the face-to-face delivery mode as a formative or summative assessment tool in medicine and nursing since 1990. The Objective Structured Clinical Assessment has been used at Charles Darwin University to assess nursing students' simulated clinical skills prior to the commencement of their clinical placements since 2008. Although the majority of the course is delivered online, students attend a one-week intensive clinical simulation block yearly, prior to attending clinical placements. Initially, the Objective Structured Clinical Assessment was introduced as a lecturer assessed summative assessment, over time it was adapted to better suit the blended learning environment. The modification of the tool from an academic to peer assessed assessment tool, was based on the empirical literature, student feedback and a cross-sectional, qualitative study exploring academics' perceptions of the Objective Structured Clinical Assessment (Bouchoucha et al., 2013a, b). This paper presents an overview of the process leading to the successful adaptation of the Objective Structured Clinical Assessment to suit the requirements of a preregistration nursing course delivered through blended learning. This is significant as many universities are moving their curriculum to fully online or blended delivery, yet little attention has been paid to adapting the assessment of simulated clinical skills. The aim is to identify the benefits and drawbacks of using the peer assessed Objective Structured Clinical Assessment and share recommendations for successful implementation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Induced fit and the entropy of structural adaptation in the complexation of CAP and lambda-repressor with cognate DNA sequences.

    Science.gov (United States)

    Dixit, Surjit B; Andrews, David Q; Beveridge, D L

    2005-05-01

    Molecular dynamics (MD) simulations of 5 ns on protein-DNA complexes of catabolite-activator protein (CAP), lambda-repressor, and their corresponding uncomplexed protein and DNA, are reported. These cases represent two extremes of DNA bending, with CAP DNA bent severely and the lambda-operator nearly straight when complexed with protein. The calculations were performed using the AMBER suite of programs and the parm94 force field, validated for these studies by good agreement with experimental nuclear magnetic resonance data on DNA. An explicit computational model of structural adaptation and computation of the quasiharmonic entropy of association were obtained from the MD. The results indicate that, with respect to canonical B-form DNA, the extreme bending of the DNA in the complex with CAP is approximately 60% protein-induced and 40% intrinsic to the sequence-dependent structure of the free oligomer. The DNA in the complex is an energetically strained form, and the MD results are consistent with a conformational-capture mechanism. The calculated quasiharmonic entropy change accounts for the entropy difference between the two cases. The calculated entropy was decomposed into contributions from protein adaptation, DNA adaptation, and protein-DNA structural correlations. The origin of the entropy difference between CAP and lambda-repressor complexation arises more from the additional protein adaptation in the case of lambda, than to DNA bending and entropy contribution from DNA bending. The entropy arising from protein DNA cross-correlations, a contribution not previously discussed, is surprisingly large.

  5. EDITORIAL Smart materials, multifunctional composites, and morphing structures: selected papers from the 20th International Conference on Adaptive Structures and Technologies (ICAST 2009) Smart materials, multifunctional composites, and morphing structures: selected papers from the 20th International Conference on Adaptive Structures and Technologies (ICAST 2009)

    Science.gov (United States)

    Liao, Wei-Hsin

    2010-12-01

    The 20th International Conference on Adaptive Structures and Technologies (ICAST) was held on 20-22 October 2009 in Hong Kong. This special section of Smart Materials and Structures is derived from the research papers presented at the conference. Of the 106 papers presented at the conference, 11 papers were reviewed and accepted for this special section, following the regular review procedures of the journal. This special section is focused on smart materials, multifunctional composites, and applications on morphing structures. Smart materials. Smart materials are the foundation of adaptive structures and intelligent systems. The development of new materials will lead to significant improvement in various applications. Three articles are focused on the fabrication of new materials and investigation of their behaviors: Barium strontium zirconate titanate ((Ba1-xSrx)(ZrxTi1-x)O3; BSZT, x = 0.25 and 0.75) ceramics with a highly crystalline structure were fabricated using the combustion technique. The microstructure of BSZT powders exhibited an almost-spherical morphology and had a porous agglomerated form. Polyaniline (PANI)/clay nanoparticles with unique core-shell structure were synthesized via Pickering emulsion polymerization. By dispersing PANI/clay nanoparticles in silicone oil, the ER fluid was made. Magnetic field effects were investigated on the deposition rate and surface morphology of chromium nitride coatings deposited by magnetron sputtering for superior hardness, excellent wear and oxidation resistance. The surface morphology of chromium nitride films was also examined by a scanning electron microscope (SEM). Multifunctional composites. Composites are made from two or more constituent materials so they can combine the best properties of different materials. Five papers deal with fabrication, testing, and modeling of various multifunctional composites: A new active structural fiber (ASF) was fabricated by coating a single carbon fiber with a concentric

  6. European Phaseolus coccineus L. landraces: population structure and adaptation, as revealed by cpSSRs and phenotypic analyses.

    Directory of Open Access Journals (Sweden)

    Monica Rodriguez

    Full Text Available Relatively few studies have extensively analysed the genetic diversity of the runner bean through molecular markers. Here, we used six chloroplast microsatellites (cpSSRs to investigate the cytoplasmic diversity of 331 European domesticated accessions of the scarlet runner bean (Phaseolus coccineus L., including the botanical varieties albiflorus, bicolor and coccineus, and a sample of 49 domesticated and wild accessions from Mesoamerica. We further explored the pattern of diversity of the European landraces using 12 phenotypic traits on 262 individuals. For 158 European accessions, we studied the relationships between cpSSR polymorphisms and phenotypic traits. Additionally, to gain insights into the role of gene flow and migration, for a subset of 115 accessions, we compared and contrasted the results obtained by cpSSRs and phenotypic traits with those obtained in a previous study with 12 nuclear microsatellites (nuSSRs. Our results suggest that both demographic and selective factors have roles in the shaping of the population genetic structure of the European runner bean. In particular, we infer the existence of a moderate-to-strong cytoplasmic bottleneck that followed the expansion of the crop into Europe, and we deduce multiple domestication events for this species. We also observe an adaptive population differentiation in the phenology across a latitudinal gradient, which suggests that selection led to the diversification of the runner bean in Europe. The botanical varieties albiflorus, bicolor and coccineus, which are based solely on flower colour, cannot be distinguished based on these cpSSRs and nuSSRs, nor according to the 12 quantitative traits.

  7. How basic psychological needs and motivation affect vitality and lifelong learning adaptability of pharmacists: a structural equation model.

    Science.gov (United States)

    Tjin A Tsoi, Sharon L N M; de Boer, Anthonius; Croiset, Gerda; Koster, Andries S; van der Burgt, Stéphanie; Kusurkar, Rashmi A

    2018-01-31

    Insufficient professional development may lead to poor performance of healthcare professionals. Therefore, continuing education (CE) and continuing professional development (CPD) are needed to secure safe and good quality healthcare. The aim of the study was to investigate the hypothesized associations and their directions between pharmacists' basic psychological needs in CE, their academic motivation, well-being, learning outcomes. Self-determination theory was used as a theoretical framework for this study. Data were collected through four questionnaires measuring: academic motivation, basic psychological needs (BPN), vitality and lifelong learning adaptability of pharmacists in the CE/CPD learning context. Structural equation modelling was used to analyze the data. Demographic factors like gender and working environment influenced the observed scores for frustration of BPN and factors like training status and working experience influenced the observed scores for academic motivation. A good model fit could be found only for a part of the hypothesized pathway. Frustration of BPN is positively directly related to the less desirable type of academic motivation, controlled motivation (0.88) and negatively directly related to vitality (- 1.61) and negatively indirectly related to learning outcomes in CE. Fulfillment or frustration of BPN are important predictors for well-being and learning outcomes. Further research should be conducted to discover how we can prevent these needs from being frustrated in order to design a motivating, vitalizing and sustainable CE/CPD system for pharmacists and other healthcare professionals. Basic psychological needs are very important predictors for well-being and learning outcomes. Further research should be conducted to discover how we can prevent these needs from being frustrated in order to design a motivating, vitalizing and sustainable CE/CPD system for pharmacists and other healthcare professionals.

  8. State recognition of the viscoelastic sandwich structure based on the adaptive redundant second generation wavelet packet transform, permutation entropy and the wavelet support vector machine

    International Nuclear Information System (INIS)

    Qu, Jinxiu; Zhang, Zhousuo; Guo, Ting; Luo, Xue; Sun, Chuang; Li, Bing; Wen, Jinpeng

    2014-01-01

    The viscoelastic sandwich structure is widely used in mechanical equipment, yet the structure always suffers from damage during long-term service. Therefore, state recognition of the viscoelastic sandwich structure is very necessary for monitoring structural health states and keeping the equipment running with high reliability. Through the analysis of vibration response signals, this paper presents a novel method for this task based on the adaptive redundant second generation wavelet packet transform (ARSGWPT), permutation entropy (PE) and the wavelet support vector machine (WSVM). In order to tackle the non-linearity existing in the structure vibration response, the PE is introduced to reveal the state changes of the structure. In the case of complex non-stationary vibration response signals, in order to obtain more effective information regarding the structural health states, the ARSGWPT, which can adaptively match the characteristics of a given signal, is proposed to process the vibration response signals, and then multiple PE features are extracted from the resultant wavelet packet coefficients. The WSVM, which can benefit from the conventional SVM as well as wavelet theory, is applied to classify the various structural states automatically. In this study, to achieve accurate and automated state recognition, the ARSGWPT, PE and WSVM are combined for signal processing, feature extraction and state classification, respectively. To demonstrate the effectiveness of the proposed method, a typical viscoelastic sandwich structure is designed, and the different degrees of preload on the structure are used to characterize the various looseness states. The test results show that the proposed method can reliably recognize the different looseness states of the viscoelastic sandwich structure, and the WSVM can achieve a better classification performance than the conventional SVM. Moreover, the superiority of the proposed ARSGWPT in processing the complex vibration response

  9. The role of genetic structure in the adaptive divergence of populations experiencing saltwater intrusion due to relative sea-level rise.

    Science.gov (United States)

    Purcell, K M; Hitch, A; Martin, S; Klerks, P L; Leberg, P L

    2012-12-01

    Saltwater intrusion into estuaries creates stressful conditions for nektonic species. Previous studies have shown that Gambusia affinis populations with exposure to saline environments develop genetic adaptations for increased survival during salinity stress. Here, we evaluate the genetic structure of G. affinis populations, previously shown to have adaptations for increased salinity tolerance, and determine the impact of selection and gene flow on structure of these populations. We found that gene flow was higher between populations experiencing different salinity regimes within an estuary than between similar marsh types in different estuaries, suggesting the development of saline-tolerant phenotypes due to local adaptation. There was limited evidence of genetic structure along a salinity gradient, and only some of the genetic variation among sites was correlated with salinity. Our results suggest limited structure, combined with selection to saltwater intrusion, results in phenotypic divergence in spite of a lack of physical barriers to gene flow. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  10. Temoporfin-loaded liposomes: physicochemical characterization.

    Science.gov (United States)

    Kuntsche, Judith; Freisleben, Ines; Steiniger, Frank; Fahr, Alfred

    2010-07-11

    Temoporfin (mTHPC) is a potent but highly hydrophobic second-generation photosensitizer and has been approved for the palliative treatment of patients with advanced head and neck cancer by photodynamic therapy. Liposome formulations have been evaluated as carrier system for this drug to overcome some problems associated with the commercial formulation Foscan where the drug is dissolved in a mixture of water-free ethanol and propylene glycol. The present study focuses on the physicochemical characterization of different liposome formulations with special emphasis on the influence of drug incorporation on the thermal phase behavior of the liposomes. In addition to conventional liposomes, pegylated lipids were used for the preparation of "stealth" liposomes. The dispersions as well as freeze-dried formulations were characterized by photon correlation spectroscopy, differential scanning calorimetry and cryo-electron microscopy. Incorporation of temoporfin resulted in a distinct concentration dependent decrease of the main phase transition of the liposomes. In case of liposomes based on dipalmitoylphosphatidylcholine/-glycerol, phase transition was close or even below body temperature. In contrast, if phospholipids with longer fatty acid chains (distearoylphosphatidylcholine/-glycerol) were used, phase transitions were well above body temperature even at high drug load. Size and thermal behavior were not distinctly influenced by the addition of pegylated lipids but cryo-electron microscopic investigations indicate the presence of micellar structures in addition to vesicles. Lyophilization and reconstitution led to an alteration in the morphology but had overall no distinct influence on the colloidal stability. 2010 Elsevier B.V. All rights reserved.

  11. The Physicochemical Quality of Traditional Burduf Cheese

    Directory of Open Access Journals (Sweden)

    Carmen Pop

    2013-11-01

    Full Text Available The aim of this study is the assessmentof the quality control of raw milk and traditional burduf cheese obtained fromcow milk mixed with 10% sheep milk. Appreciation of the integrity and freshness assessmentof milk (cow and sheep was tested by physico-chemical analysis.On theshelf-live were determined the physico-chemical parameters in cheese samples. Theantibiotics residues were tested of the milk samples with portable analyser,model Rosa Charm Reader. Theresults of physico-chemical determinations for the milk and cheese samples werewithin the maximum permissible by data legislation. Regardingthe content of antibiotics, the results were negative both for cow milk and forsheep milk. The sensorycharacteristics of burduf cheese are influenced by the different types of milk.

  12. Relationship between physicochemical parameters and ...

    African Journals Online (AJOL)

    The aim of the research was to study the leaf epidermal structures and stomata ontogeny in some members of the family Lamiaceae. The species used in this study were Vitex doniana, Gmelina arborea and Tectona grandis. Leaf epidermal structures, stomata types, sizes, distribution and development were examined and to ...

  13. Adaptive-Positive vs. Maladaptive-Negative Structures and Processes in Learning: Towards the Comprehensive Model of Academic Performance

    OpenAIRE

    Rogaten, Jekaterina

    2014-01-01

    The goal of this Ph.D. research was to develop an empirical foundation suitable for designing educational interventions and programmes aiming to improve students’ learning. In order to achieve this, a series of studies was conducted that supported the development and test of a comprehensive, chained mediation model of academic performance. The proposed chained mediation model comprised of adaptive-positive and maladaptive-negative submodels. The adaptive-positive submodel hypothesised firstly...

  14. Actinide physicochemical data assessment and selection

    International Nuclear Information System (INIS)

    Navratil, J.D.

    1984-01-01

    There is a continuing need to have reliable physicochemical data of actinide compounds and actinide elements in aqueous solution available for nuclear engineers and scientists. These data are needed for all aspects of the nuclear fuel cycle - from the behavior of actinides in reactor fuels at high temperature and pressure to actinide behavior in geologic depository environments. This paper summarizes the status of actinide physicochemical data assessment and selection. The topics to be covered include data assessment of chemical thermodynamic properties and solubilities of actinide compounds and solution equilibria of the actinides

  15. Validation of the National Institutes of Health Stroke Scale, modified Rankin Scale and Barthel Index in Brazil: the role of cultural adaptation and structured interviewing.

    Science.gov (United States)

    Cincura, Carolina; Pontes-Neto, Octavio M; Neville, Iuri S; Mendes, Henrique F; Menezes, Daniela F; Mariano, Débora C; Pereira, Issana F; Teixeira, Larissa A; Jesus, Pedro A P; de Queiroz, Danilo C L; Pereira, Davidson F; Pinto, Elen; Leite, João P; Lopes, Antonio A; Oliveira-Filho, Jamary

    2009-01-01

    We aimed to validate three widely used scales in stroke research in a multiethnic Brazilian population. The National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS) and Barthel Index (BI) were translated, culturally adapted and applied by two independent investigators. The mRS was applied with or without a previously validated structured interview. Interobserver agreement (kappa statistics) and intraclass correlation coefficients were calculated. 84 patients underwent mRS (56 with and 28 without a structured interview), 57 BI and 62 NIHSS scoring. Intraclass correlation coefficient was 0.902 for NIHSS and 0.967 for BI. For BI, interobserver agreement was good (kappa = 0.70). For mRS, the structured interview improved interobserver agreement (kappa = 0.34 without a structured interview; 0.75 with a structured interview). The NIHSS, BI and mRS show good validity when translated and culturally adapted. Using a structured interview for the mRS improves interobserver concordance rates. Copyright (c) 2008 S. Karger AG, Basel.

  16. Adaptive and active materials: selected papers from the ASME 2012 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 12) (Stone Mountain, GA, USA, 19-21 September 2012)

    Science.gov (United States)

    Seelecke, Stefan; Erturk, Alper; Ounaies, Zoubeida; Naguib, Hani; Huber, John; Turner, Travis; Anderson, Iain; Philen, Michael; Baba Sundaresan, Vishnu

    2013-09-01

    The fifth annual meeting of the ASME/AIAA Smart Materials, Adaptive Structures and Intelligent Systems Conference (SMASIS) was held in beautiful Stone Mountain near Atlanta, GA. It is the conference's objective to provide an up-to-date overview of research trends in the entire field of smart materials systems. This was reflected in keynote speeches by Professor Eduard Arzt (Institute of New Materials and Saarland University, Saarbrücken, Germany) on 'Micro-patterned artificial 'Gecko' surfaces: a path to switchable adhesive function', by Professor Ray H Baughman (The Alan G MacDiarmid NanoTech Institute, University of Texas at Dallas) on 'The diverse and growing family of carbon nanotube and related artificial muscles', and by Professor Richard James (University of Minnesota) on 'The direct conversion of heat to electricity using multiferroic materials with phase transformations'. SMASIS 2012 was divided into eight symposia which span basic research, applied technological design and development, and industrial and governmental integrated system and application demonstrations. • SYMP 1. Development and characterization of multifunctional materials. • SYMP 2. Mechanics and behavior of active materials. • SYMP 3. Modeling, simulation and control of adaptive systems. • SYMP 4. Integrated system design and implementation. • SYMP 5. Structural health monitoring/NDE. • SYMP 6. Bio-inspired materials and systems. • SYMP 7. Energy harvesting. • SYMP 8. Structural and materials logic. This year we were particularly excited to introduce a new symposium on energy harvesting, which has quickly matured from a special track in previous years to an independent symposium for the first time. The subject cuts across fields by studying different materials, ranging from piezoelectrics to electroactive polymers, as well as by emphasizing different energy sources from wind to waves and ambient vibrations. Modeling, experimental studies, and technology applications all

  17. Spatial structure and climatic adaptation in African maize revealed by surveying SNP diversity in relation to global breeding and landrace panels.

    Directory of Open Access Journals (Sweden)

    Ola T Westengen

    Full Text Available BACKGROUND: Climate change threatens maize productivity in sub-Saharan Africa. To ensure food security, access to locally adapted genetic resources and varieties is an important adaptation measure. Most of the maize grown in Africa is a genetic mix of varieties introduced at different historic times following the birth of the trans-Atlantic economy, and knowledge about geographic structure and local adaptations is limited. METHODOLOGY: A panel of 48 accessions of maize representing various introduction routes and sources of historic and recent germplasm introductions in Africa was genotyped with the MaizeSNP50 array. Spatial genetic structure and genetic relationships in the African panel were analysed separately and in the context of a panel of 265 inbred lines representing global breeding material (based on 26,900 SNPs and a panel of 1127 landraces from the Americas (270 SNPs. Environmental association analysis was used to detect SNPs associated with three climatic variables based on the full 43,963 SNP dataset. CONCLUSIONS: The genetic structure is consistent between subsets of the data and the markers are well suited for resolving relationships and admixture among the accessions. The African accessions are structured in three clusters reflecting historical and current patterns of gene flow from the New World and within Africa. The Sahelian cluster reflects original introductions of Meso-American landraces via Europe and a modern introduction of temperate breeding material. The Western cluster reflects introduction of Coastal Brazilian landraces, as well as a Northeast-West spread of maize through Arabic trade routes across the continent. The Eastern cluster most strongly reflects gene flow from modern introduced tropical varieties. Controlling for population history in a linear model, we identify 79 SNPs associated with maximum temperature during the growing season. The associations located in genes of known importance for abiotic stress

  18. Compensatory Structural and Functional Adaptation after Radical Nephrectomy for Renal Cell Carcinoma According to Preoperative Stage of Chronic Kidney Disease.

    Science.gov (United States)

    Choi, Don Kyoung; Jung, Se Bin; Park, Bong Hee; Jeong, Byong Chang; Seo, Seong Il; Jeon, Seong Soo; Lee, Hyun Moo; Choi, Han-Yong; Jeon, Hwang Gyun

    2015-10-01

    We investigated structural hypertrophy and functional hyperfiltration as compensatory adaptations after radical nephrectomy in patients with renal cell carcinoma according to the preoperative chronic kidney disease stage. We retrospectively identified 543 patients who underwent radical nephrectomy for renal cell carcinoma between 1997 and 2012. Patients were classified according to preoperative glomerular filtration rate as no chronic kidney disease--glomerular filtration rate 90 ml/minute/1.73 m(2) or greater (230, 42.4%), chronic kidney disease stage II--glomerular filtration rate 60 to less than 90 ml/minute/1.73 m(2) (227, 41.8%) and chronic kidney disease stage III--glomerular filtration rate 30 to less than 60 ml/minute/1.73 m(2) (86, 15.8%). Computerized tomography performed within 2 months before surgery and 1 year after surgery was used to assess functional renal volume for measuring the degree of hypertrophy of the remnant kidney, and the preoperative and postoperative glomerular filtration rate per unit volume of functional renal volume was used to calculate the degree of hyperfiltration. Among all patients (mean age 56.0 years) mean preoperative glomerular filtration rate, functional renal volume and glomerular filtration rate/functional renal volume were 83.2 ml/minute/1.73 m(2), 340.6 cm(3) and 0.25 ml/minute/1.73 m(2)/cm(3), respectively. The percent reduction in glomerular filtration rate was statistically significant according to chronic kidney disease stage (no chronic kidney disease 31.2% vs stage II 26.5% vs stage III 12.8%, p kidney was not statistically significant (no chronic kidney disease 18.5% vs stage II 17.3% vs stage III 16.5%, p=0.250). The change in glomerular filtration rate/functional renal volume was statistically significant (no chronic kidney disease 18.5% vs stage II 20.1% vs stage III 45.9%, p chronic kidney disease stage (p <0.001). Patients with a lower preoperative glomerular filtration rate had a smaller reduction in

  19. Enhanced oxygen vacancy diffusion in Ta{sub 2}O{sub 5} resistive memory devices due to infinitely adaptive crystal structure

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Hao [San Jose Research Center, HGST, a Western Digital company, San Jose, California 95135 (United States); Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706 (United States); Stewart, Derek A., E-mail: derek.stewart@hgst.com [San Jose Research Center, HGST, a Western Digital company, San Jose, California 95135 (United States)

    2016-04-07

    Metal oxide resistive memory devices based on Ta{sub 2}O{sub 5} have demonstrated high switching speed, long endurance, and low set voltage. However, the physical origin of this improved performance is still unclear. Ta{sub 2}O{sub 5} is an important archetype of a class of materials that possess an adaptive crystal structure that can respond easily to the presence of defects. Using first principles nudged elastic band calculations, we show that this adaptive crystal structure leads to low energy barriers for in-plane diffusion of oxygen vacancies in λ phase Ta{sub 2}O{sub 5}. Identified diffusion paths are associated with collective motion of neighboring atoms. The overall vacancy diffusion is anisotropic with higher diffusion barriers found for oxygen vacancy movement between Ta-O planes. Coupled with the fact that oxygen vacancy formation energy in Ta{sub 2}O{sub 5} is relatively small, our calculated low diffusion barriers can help explain the low set voltage in Ta{sub 2}O{sub 5} based resistive memory devices. Our work shows that other oxides with adaptive crystal structures could serve as potential candidates for resistive random access memory devices. We also discuss some general characteristics for ideal resistive RAM oxides that could be used in future computational material searches.

  20. Physicochemical Properties of Starch Isolated from Bracken (Pteridium aquilinim) Rhizome.

    Science.gov (United States)

    Yu, Xurun; Wang, Jin; Zhang, Jing; Wang, Leilei; Wang, Zhong; Xiong, Fei

    2015-12-01

    Bracken (Pteridium aquilinum) is an important wild plant starch resource worldwide. In this work, starch was separated from bracken rhizome, and the physicochemical properties of this starch were systematically investigated and compared with 2 other common starches, that is, starches from waxy maize and potato. There were significant differences in shape, birefringence patterns, size distribution, and amylose content between bracken and the 2 other starches. X-ray diffraction analysis revealed that bracken starch exhibited a typical C-type crystalline structure. Bracken starch presented, respectively, lower and higher relative degree of crystallinity than waxy maize and potato starches. Ordered structures in particle surface differed among these 3 starches. The swelling power tendency of bracken starch in different temperature intervals was very similar to that of potato starch. The viscosity parameters during gelatinization were the lowest in waxy maize, followed by bracken and potato starches. The contents of 3 nutritional components, that is, rapidly digestible, slowly digestible, and resistant starches in native, gelatinized, and retrograded starch from bracken rhizome presented more similarities with potato starch than waxy maize starch. These finding indicated that physicochemical properties of bracken starch showed more similarities with potato starch than waxy maize starch. © 2015 Institute of Food Technologists®

  1. Physicochemical and viscoelastic properties of honey from medicinal plants.

    Science.gov (United States)

    Nguyen, Huong Thi Lan; Panyoyai, Naksit; Paramita, Vilia Darma; Mantri, Nitin; Kasapis, Stefan

    2018-02-15

    The present work investigated the physicochemical and structural properties of Tulsi, Alfalfa and two varieties of Manuka honey derived from medicinal plants. Chemical analysis yielded data on the content of reducing sugars (glucose and fructose) that dominate the honey matrix, and of the minor constituents of protein, phenols and flavonoids. Standard chemical assays were used to develop a database of water content, electrical conductivity, pH, ash content, visual appearance and colour intensity. Physicochemical characteristics were related to structural behaviour of the four honey types, as recorded by small-deformation dynamic oscillation in shear, micro- and modulated differential scanning calorimetry, wide angle X-ray diffraction and infrared spectroscopy. The preponderance of hydrogen bonds in intermolecular associations amongst monosaccharides in honey yields a semi-amorphous or semi-crystalline system. That allowed prediction of the calorimetric and mechanical glass transition temperatures that demarcate the passage from liquid-like to solid-like consistency at subzero temperatures. Copyright © 2017. Published by Elsevier Ltd.

  2. Chemical composition, physicochemical and functional properties of ...

    African Journals Online (AJOL)

    The results of chemical composition, physicochemical and functional properties for both lupin samples indicated that lupins can be used as a raw material for various food products manufacturing and provide consistency in food processing, analogous to other food legumes. Therefore, the research findings can be used by ...

  3. A comparative study of microbiological and physicochemical ...

    African Journals Online (AJOL)

    A comparative study of microbiological and physicochemical characteristics of water distributed from two water treatment plants in Rwanda. ... Thus, as recommendation to WASAC authority, there is a need for improvement in the water management strategy for better water quality especially along the distribution network.

  4. Physicochemical, antioxidant, and sensorial properties of peach ...

    African Journals Online (AJOL)

    Preparation of varieties of processed peach products could be a good option to supply in lean season. Objective of the study was to assess the quality characteristics of peach snacks prepared from 11 different cultivars. We investigated the physicochemical (soluble solid, titratable acidity, hardness and dry yield), antioxidant ...

  5. Physicochemical and Bacteriological Characteristics of Rainwater ...

    African Journals Online (AJOL)

    ADOWIE PERE

    This study investigated the physicochemical and bacteriological characteristics of rainwater harvested from three different rooftop sheets in Esan West Local Government Area, Edo State. Parameters investigated include pH, TSS, TDS, Turbidity, Acidity, Ca2+, Fe, Pb, Cr, TBC, TCC and E-coli. The results showed that mean ...

  6. Physicochemical Characteristics of groundwater quality from Yola ...

    African Journals Online (AJOL)

    MICHAEL

    ABSTRACT: Some physicochemical parameters related to groundwater quality obtained from Yola Area of. Northeastern Nigeria was investigated for the purpose of drinking and irrigation. An attempt was also made to develop linear regression equations to predict the concentration of water quality having significant ...

  7. Heavy metal levels, physicochemical properties and microbial ...

    African Journals Online (AJOL)

    Journal of Applied Sciences and Environmental Management ... out to assess the microbial, physicochemical and heavy metal characteristics of soil samples from five different waste collection sites within the University of Benin, Benin City and evaluated using standard analytical and classical microbiological methods.

  8. Distinct physicochemical characteristics of different beef from ...

    African Journals Online (AJOL)

    Jane

    2011-04-11

    Apr 11, 2011 ... A total of 30 Qinchuan cattle were used to investigate the physicochemical characteristics of beef from three different parts of cattle carcass, namely longissimus dorsi (LD), serratus ventralis (SV) and semitendinosus (ST). Multiple parameters were ranked in the descending order of ST > SV > LD, and.

  9. Physicochemical characteristics of communal rangeland soils along ...

    African Journals Online (AJOL)

    This study investigated the relative association of surface (0–20 cm) soil physicochemical properties, viz. electrical conductivity, cation exchange capacity (CEC), soil organic carbon, available phosphorus, particle size composition, soil aggregate stability and microbial respiration, along a toposequence in two vegetation ...

  10. Determination of the chemical composition, the physicochemical ...

    African Journals Online (AJOL)

    The chemical composition of the seed of Telfairia occidentalis (fluted pumpkin), the physicochemical properties of the seed oil and the amino acids profiles of the seed protein have been determined. In proximate composition, the crude fat content of 58.41% indicates that the plant seed is an oil seed. Its protein content of ...

  11. Physicochemical, Nutritional, and Functional Characteristics of ...

    African Journals Online (AJOL)

    ... a good source of nutritional components and essential nutrients, including minerals and amino acids, and have functional properties, which, if properly utilized, can improve human nutrition and health. Keywords: Grewia tenax, Physicochemical, Amino acids, Nutrition, Functional properties, Minerals, Volatile compounds ...

  12. Physico-Chemical Characterization and Pollution Index ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    inorganic macro components (common cations and .... Table 2: Concentration of Physicochemical Parameters of leachates from Igbudu Market waste dumpsite ..... general, the condition in each of the dumpsites investigated determines the concentration of heavy metals in later years. The lead concentration a mean value of ...

  13. Physicochemical characteristics of geophagic clayey soils from ...

    African Journals Online (AJOL)

    ONOS

    2010-09-06

    Sep 6, 2010 ... Physicochemical properties of geophagic clayey soils from South Africa and Swaziland were determined in order to appreciate their capability to perform the functions for which they are consumed and possible consequences of the practice in humans. Tests conducted included colour, texture, pH, electrical ...

  14. Physicochemical and textural properties of kombucha fermented ...

    African Journals Online (AJOL)

    The possibility of kombucha application cultivated on two different tea types in combination with probiotics for milk fermentation at different temperatures, as well as the physicochemical and textural properties of manufactured fermented milk products were investigated. Combination of probiotic starter culture and kombucha ...

  15. Comparative Studies on Some Physicochemical Properties of ...

    African Journals Online (AJOL)

    Industrial and nutritional processes have increased the demands for oil and this in turn has led to the search for oils from different types of seeds. It is in this vein that baobab seed oil was extracted, analyzed and some of it physicochemical properties compared with those of vegetable, peanut and palm oils. The percentage ...

  16. Physicochemical characterization of traditional Ghanaian cooking ...

    African Journals Online (AJOL)

    Traditional vegetable oils derived from Egusi (Citrullus colocynthis) and Werewere (Cucumeropsis manni) could prove to be an important commodity for Ghanaians, serving as a potential alternative source of common cooking oils. This study measured several physicochemical properties of Egusi and Werewere oils to ...

  17. Assessment of Physicochemical Characteristics of Selected ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: The physicochemical parameters of seven different borehole waters in Oke-Oyi, Ilorin East Local ... water source due to its lower tendency to be polluted ... samples were collected into polythene bottles prewashed with detergent, diluted HNO3 and distilled de-ionised water. Samples for heavy metal analysis.

  18. Physicochemical Characterization of Inclusion Complex of Catechin ...

    African Journals Online (AJOL)

    Its physicochemical properties were investigated by ultravioletvisible spectrometry (UV), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). Results: The characteristic UV absorption peaks for catechin, the physical ...

  19. Preparation and physicochemical evaluation of transdermal ...

    African Journals Online (AJOL)

    Purpose: To prepare transdermal ketoprofen metered-dose aerosol formulations containing menthol and isopropyl myristate (IPM) as penetration enhancers and to evaluate their physicochemical and permeation properties. Methods: Selected ratios of ketoprofen, ethanol, polyvinylpyrrolidone K30 (PVP K30, anti-nucleant),.

  20. Comparison of Effects of Oligosaccharides on Physicochemical ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of different oligosaccharides on the physicochemical properties of corn starch. Methods: The blue value and retrogradation of corn starch were evaluated following the addition of different oligosaccharides and compared with control. Pasting properties, melting enthalpy and melting.

  1. Physicochemical, bacteriological and metal analysis of some ...

    African Journals Online (AJOL)

    This study was investigates the physicochemical, microbial and metal contents of water samples obtained from three different surface waters (Ala river, Onyearugbulem stream and FUTA stream).The samples were collected in the early the early morning during the late rainy season of August 2010. The streams are all ...

  2. Physicochemical and microbiological characteristics of Italian salami ...

    African Journals Online (AJOL)

    The purpose of this study was to evaluate and compare the inclusion of different levels of pequi (Caryocar Brasiliense, Cambess) pulp in the processing of Italian salami made of lamb for the evaluation of their physicochemical and microbiological characteristics. Six formulations of Italian salamis were processed: no pequi ...

  3. Physico-Chemical Characterization and Pollution Index ...

    African Journals Online (AJOL)

    Physico-Chemical Characterization and Pollution Index Determination of Leachates from Warri Waste Dumpsite, Southern Nigeria. ... This study characterizes the leachates quality of an active dumpsite in Warri, Delta State and also analyses its contamination or pollution potential. Leachate Pollution Index (LPI) - a tool for ...

  4. Examination of rheological and physicochemical characteristics in ...

    African Journals Online (AJOL)

    The aim of the study was to determine the effect of the biological origin and temperature on rheological and physicochemical characteristics of honey. The honey of the selected varieties differed in color, scent, microstructure, total acidity, moisture, and pH. The level of moisture statistically significantly correlated with the ...

  5. Physicochemical properties of nanostructured lipid carriers as ...

    African Journals Online (AJOL)

    The melting point depression of NLC80 was 5.71°C below bulk lipid's melting point (61.56°C), while NLC20 exhibited two melting points at 54.80 and 59.10°C. ... Key words: Nanostructured lipid carriers, colloidal delivery system, polysorbate 80, polysorbate 20, highpressure homogenization, physicochemical properties.

  6. Isolation and Physicochemical Characterization of Lignin from ...

    African Journals Online (AJOL)

    The isolated lignins were characterized by some physico-chemical parameters and spectroscopy methods like Futran Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Lignin from Chromolaena odorata was found to be more pure than the one from Tithonia diversifolia as evident from the ...

  7. Physicochemical Characteristics of Water Available for Livestock ...

    African Journals Online (AJOL)

    The study was carried out to determine physicochemical properties of water available for livestock and human use in Lala District, Gombi Local Government Area of Adamawa State, North eastern Nigeria. Questionnaire,oral interview and visual observations were employed to evaluate the physical quality of the water ...

  8. Physicochemical composition and antioxidant properties of a ...

    African Journals Online (AJOL)

    Physicochemical composition and antioxidant properties of a sweetpotato variety ( Ipomoea batatas L) commercially sold in South Eastern Nigeria. ... Results show that this sweet potato variety has potentials of biological properties and could have wide utility in food, alcohol and sugar industries. In addition, it could serve as ...

  9. Microbiological, physicochemical properties and biogenic amine ...

    African Journals Online (AJOL)

    Thirty three strained yoghurt samples were collected from local open markets in different provinces of Turkey (Afyon [AF], Aydın [AY], Burdur [B], Isparta [I] and Muğla [M]). Physicochemical and microbiological properties, as well as biogenic amine content, were examined in each of the samples. The dry matter (17.90 to ...

  10. Physicochemical characteristics of osmotically dehydrated tomato ...

    African Journals Online (AJOL)

    Physicochemical characteristics of osmotically dehydrated tomato (Lycopersicon esculentum) under different common drying methods. JAV Famurewa, AO Raji. Abstract. This study investigated the effect of different common drying methods on the chemical composition of osmotically dehydrated tomato. The quality of ...

  11. Evaluation of Physicochemical Properties and Heavy Metals ...

    African Journals Online (AJOL)

    Physicochemical properties of municipal dumpsite compost in Kano metropolis and concentration of heavy metals were investigated. Analysis was carried out by atomic absorption spectrometry (Buck Scientific VPG 210). The results shows that the compost pH (6.63-8.19), electric conductivity of compost (638-933μs/cm), ...

  12. Correlations between soil microbial and physicochemical variations ...

    Indian Academy of Sciences (India)

    Prakash

    Soil management practices alter the physicochemical properties of soil, and the soil microbial community may respond to these changes in ways that affect the ability of the soil to resist soil-borne diseases. Soil microbial diversity drops when the soil is subjected to intensive exploitation during agricultural production.

  13. Assessment of microbiological and physicochemical parameters of ...

    African Journals Online (AJOL)

    The main objective of our study was to determine the physicochemical and microbiological characteristics of two water samples: river and ground water, in Gikondo industrial park, compared to the tap water. Samples were collected from the main three sources: industrial park effluent water (river water), industrial spring ...

  14. Physicochemical, toxicological and ecological analysis of ...

    African Journals Online (AJOL)

    Dams built to supply electricity, irrigation and fresh water, change the characteristics of the region they are located. The ecological, limnological characteristics and the quality of water in the dam reservoir deteriorate with time. In this study, the physicochemical, toxicological and ecological parameters of Gökçekaya Dam ...

  15. Comparative physicochemical and genotoxicity assessments of ...

    African Journals Online (AJOL)

    The textile industry has become indispensable in view of its basic and social importance to human life, but its environmental impact has continued to be a subject of concern. The objectives of the present study were to assess and compare the physico-chemical and genotoxicity properties of a corporate textile mill effluent ...

  16. Evaluation of Physicochemical, Functional and Sensory Properties ...

    African Journals Online (AJOL)

    Evaluation of Physicochemical, Functional and Sensory Properties of Fermented Fura Powder Supplemented with Soy. ... Nigerian Food Journal ... and sensory properties while another sample was stored at room temperature; samples were withdrawn at intervals of 4 and 6 weeks for some functional properties evaluation.

  17. TEMPORAL AND SPATIAL PHYSICOCHEMICAL WATER QUALITY ...

    African Journals Online (AJOL)

    TEMPORAL AND SPATIAL PHYSICOCHEMICAL WATER QUALITY. IN BLANTYRE URBAN STREAMS. S.M. Kuyeli1, W.R.L Masamba. ∗2. , E. Fabiano3, S.M. Sajidu3, E.M.T. Henry4. 1Blantyre City Assembly Pollution Control Office, Private Bag 67, Blantyre, Malawi. 2Harry Oppenheimer Okavango Research Centre, ...

  18. Assessment of Physicochemical Characteristics of Produced Water ...

    African Journals Online (AJOL)

    This study evaluated the physico-chemical characteristics, total hydrocarbon concentration (THC) and some heavy metal levels of produced water from terminals of two oil industry facilities in Nigeria, using standard methods. Appropriate sample bottles were used in the collection of samples for analyses of BOD, other ...

  19. Physicochemical changes of raffia sap ( Raphia mambillensis ...

    African Journals Online (AJOL)

    The chemical content of a substance can influence its shelf life. Fermentation causes changes in freshly tapped sap and therefore makes its large scale use difficult. In order to study the effect of time on fermentation on the raffia sap property, its physico-chemical and microbiological characteristics were determined during ...

  20. Physicochemical properties of nanoparticles titania from alcohol ...

    African Journals Online (AJOL)

    The physicochemical properties of synthesized TiO2 nanoparticles from integrating sol-gel with flame-based techniques were studied. The synthesized nanoparticles properties were compared after using methanol, ethanol, and propanol fuel sources. The synthesized TiO2 were characterized by X-ray diffraction (XRD), ...

  1. Seasonal variation in fish abundance and physicochemical ...

    African Journals Online (AJOL)

    There is a positive correlation between fish abundance and biomass for wet and dry seasons (r = 0.60 and 0.76 respectively). There was no significant difference between fish abundance in the two seasons. Variations occurred between physico-chemical parameters of water samples. Analysis of the lagoon waters showed ...

  2. Bacteriological and physicochemical evaluation of syrups produced ...

    African Journals Online (AJOL)

    Bacteriological and physicochemical evaluation of syrups produced from local starch sources. ... The syrups were produced, using acid hydrolysis, from starches obtained from Colocasia esculenta, Zea mays and Manihot palmata. The viable bacterial count gave low counts of Leuconostoc mesenteroides, Bacillus subtills ...

  3. Bacteriological, physicochemical and mineral studies on Awedele ...

    African Journals Online (AJOL)

    EJIRO

    physicochemical quality of the water samples was also assessed. The mineral content of the adjacent soil samples was also determined. Antibiotic resistance among isolated Enterococcus species was highest to penicillin as all isolates demonstrated complete resistance to the antibiotics. Prevalence of gentamycin-.

  4. Using of phytoplankton and physicochemical parameters as ...

    African Journals Online (AJOL)

    Samples were collected from six sites covering the lake Timsah during the period summer 2005-spring 2006, representing the four seasons, including water and phytoplankton samples, in order to evaluating phytoplankton algal community and physicochemical parameters. A total of One-hundard and two taxa have been ...

  5. Comparative evaluation of the physicochemical composition and ...

    African Journals Online (AJOL)

    Eleazu Chinedum

    2012-09-24

    Sep 24, 2012 ... The physicochemical composition and microbial quality of 7 different water sources (Umudike ukwu bore hole (B5) ... bore hole (B4), Umudike school borehole A (B7), Umudike school bore hole B (B6) and Ahiaeke bore hole (B9) used for root and ..... water sample. Polluted and waste water has higher BOD.

  6. Comparison of Effects of Oligosaccharides on Physicochemical ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of different oligosaccharides on the physicochemical properties of corn starch. Methods: The blue value and retrogradation of corn starch were evaluated following the addition of different oligosaccharides and compared with control. Pasting properties, melting enthalpy and melting ...

  7. Physicochemical and antimicrobial properties of Trichosanthes ...

    African Journals Online (AJOL)

    The core objective of this research was to determine the characteristics of oils, nutritional composition and antimicrobial activities of T. anguina and S. mahagoni seeds. Physicochemical characteristics of oils implied higher degree of unsaturation in T. anguina whereas, S. mahagoni oil contained appreciable level of ...

  8. Physicochemical and sensory characteristics of yoghurt produce ...

    African Journals Online (AJOL)

    Objective: To evaluate the physicochemical and sensory acceptability of yoghurt produced from ewe, goat and a mixture of ewe milk and goat milk in Nigeria in order for the populace to harness the nutritional and therapeutic benefits of the milks. Methods: Samples of whole cow milk (WCM) as standard, goat milk (GM), ewe ...

  9. Physicochemical parameters and antibiotics residuals in Algerian ...

    African Journals Online (AJOL)

    The physicochemical analyses of the Algerian honeys show that 56% of samples correspond to Codex standards and 44% not in conformity with the standards required by the Codex Alimentarius and EU, because part of the samples had one or more defects. The percentage not in conformity was due to the high rates of ...

  10. Determination of Selected Physicochemical Parameters and Heavy ...

    African Journals Online (AJOL)

    This was evident in lack of plant growth noticed in the study area as a result of depletion of NPK values below specified value by USDA Standards for plant growth. The high level of contamination of some of the physicochemical parameters and heavy metals as seen in this project underscores the need for due diligence in ...

  11. ASSESSMENT OF PHYSICO-CHEMICAL PARAMETERS OF ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    analyzed for various physico-chemical parameters. The study indicated that the mean value of studied parameters, except electrical conductivity, total dissolved solids, turbidity, total alkalinity, calcium ion, sulphate ion, and total phosphorus of the river water samples were within the permissible limit of WHO for drinking water ...

  12. Physicochemical and powder properties of alpha- and ...

    African Journals Online (AJOL)

    Cob alpha-celluloses (CAC) was extracted from maize cobs by defibering, delignification and bleaching; then subjected to acid hydrolysis to obtain Cob- microcrystalline-cellulose (CMCC). Their physicochemical properties were evaluated and compared with those of Avicel®, a commercial variety of microcrystalline ...

  13. Physicochemical Flux and Phytoplankton diversity in Shagari ...

    African Journals Online (AJOL)

    USER

    2007-03-20

    Mar 20, 2007 ... Physicochemical Flux and Phytoplankton diversity in Shagari Reservoir,Sokoto, Nigeria. *1I.M. Magami, 1T. Adamu and 2A.A. Aliero. 1Zoology Unit, Department of Biological Sciences, Usmanu Danfodiyo University, Sokoto, Nigeria. 2Botany Unit, Department of Biological Sciences, Usmanu Danfodiyo ...

  14. Physico-chemical water characteristics and aquatic ...

    African Journals Online (AJOL)

    Physico-chemical water characteristics and aquatic macroinvertebrates of Lake Tsimanampesotse, south-western Madagascar. ... Water quality and aquatic invertebrates were investigated in April and August 2013 to provide baseline data in order to measure possible changes of the area in the future. Changes in water ...

  15. Comparative Studies on Some Physicochemical Properties of ...

    African Journals Online (AJOL)

    ABSTRACT: Industrial and nutritional processes have increased the demands for oil and this in turn has led to the search for oils from different types of seeds. It is in this vein that baobab seed oil was extracted, analyzed and some of it physicochemical properties compared with those of vegetable, peanut and palm oils.

  16. SOME PHYSICOCHEMICAL PROPERTIES AND APPLICATION OF ...

    African Journals Online (AJOL)

    The α-cellulose was also employed as disintegrant in some tablet formulations. Some of the physicochemical and flow properties evaluated were, moisture content, bulk density, packed density, Carrs compressibility, angle of repose and Hausner quotient. The tablet properties studied were, disintegration time, hardness, ...

  17. Beneficial reuse of fly ashes in geotechnical engineering with physicochemical and electron microscopic methods.

    Science.gov (United States)

    2013-06-01

    The sedimentation behavior of fine grained soil is largely dependent on its pore fluid chemistry. Physicochemical properties of the : pore fluid, such as ionic strength and pH, could greatly influence the micro structure of kaolinite which in turn in...

  18. Adaptive solution of the multigroup diffusion equation on irregular structured grids using a conforming finite element method formulation

    International Nuclear Information System (INIS)

    Ragusa, J. C.

    2004-01-01

    In this paper, a method for performing spatially adaptive computations in the framework of multigroup diffusion on 2-D and 3-D Cartesian grids is investigated. The numerical error, intrinsic to any computer simulation of physical phenomena, is monitored through an a posteriori error estimator. In a posteriori analysis, the computed solution itself is used to assess the accuracy. By efficiently estimating the spatial error, the entire computational process is controlled through successively adapted grids. Our analysis is based on a finite element solution of the diffusion equation. Bilinear test functions are used. The derived a posteriori error estimator is therefore based on the Hessian of the numerical solution. (authors)

  19. Adaptive and active materials: selected papers from the ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 13) (Snowbird, UT, USA, 16-18 September 2013)

    Science.gov (United States)

    Johnson, Nancy; Naguib, Hani; Turner, Travis; Anderson, Iain; Bassiri-Gharb, Nazanin; Daqaq, Mohammed; Baba Sundaresan, Vishnu; Sarles, Andy

    2014-10-01

    The sixth annual meeting of the ASME Smart Materials, Adaptive Structures and Intelligent Systems Conference (SMASIS) was held in the beautiful mountain encircled Snowbird Resort and Conference Center in Little Cottonwood Canyon near Salt Lake City, Utah. It is the conference's objective to provide an up-to-date overview of research trends in the entire field of smart materials systems in a friendly casual forum conducive to the exchange of ideas and latest results. As each year we strive to grow and offer new experiences, this year we included special focused topic tracks on nanoscale multiferroic materials and origami engineering. The cross-disciplinary emphasis was reflected in keynote speeches by Professor Kaushik Bhattacharya (California Institute of Technology) on 'Cyclic Deformation and the Interplay between Phase Transformation and Plasticity in Shape Memory Alloys', by Professor Alison Flatau (University of Maryland at College Park) on 'Structural Magnetostrictive Alloys: The Other Smart Material', and by Dr Leslie Momoda (Director of the Sensors and Materials Laboratories, HRL Laboratories, LLC, Malibu, CA) on 'Architecturing New Functional Materials: An Industrial Perspective'. SMASIS 2013 was divided into seven symposia which span basic research, applied technological design and development, and industrial and governmental integrated system and application demonstrations. SYMP 1. Development and Characterization of Multifunctional Materials. SYMP 2. Mechanics and Behavior of Active Materials. SYMP 3. Modeling, Simulation and Control of Adaptive Systems. SYMP 4. Integrated System Design and Implementation. SYMP 5. Structural Health Monitoring. SYMP 6. Bioinspired Smart Materials and Systems. SYMP 7. Energy Harvesting. Authors of selected papers in the materials areas (symposia 1, 2, and 6) as well as energy harvesting (symposium 7) were invited to write a full journal article on their presentation topic for publication in this special issue of Smart

  20. The masticatory system under varying functional load. Part 1: structural adaptation of rabbit jaw muscles to reduced masticatory load

    NARCIS (Netherlands)

    Vreeke, M.; Langenbach, G.E.J.; Korfage, J.A.M.; Zentner, A.; Grünheid, T.

    2011-01-01

    Skeletal muscle fibres can change their myosin heavy-chain (MyHC) isoform and cross-sectional area, which determine their contraction velocity and maximum force generation, respectively, to adapt to varying functional loads. In general, reduced muscle activity induces transition towards faster

  1. Cloning, expression and structural stability of a cold-adapted ß-Galactosidase from Rahnella sp.R3

    Science.gov (United States)

    A novel gene was isolated for the first time from a psychrophilic gram-negative bacterium Rahnella sp.R3. It encoded a cold-adapted ß-galactosidase (R-ß-Gal). Recombinant R-ß-Gal was expressed in Escherichia coli BL21 (DE3), purified, and characterized. R-ß-Gal belongs to the glycosyl hydrolase fami...

  2. Adapt or Die

    DEFF Research Database (Denmark)

    Brody, Joshua Eric; Larsen, Kasper Green

    2015-01-01

    In this paper, we study the role non-adaptivity plays in maintaining dynamic data structures. Roughly speaking, a data structure is non-adaptive if the memory locations it reads and/or writes when processing a query or update depend only on the query or update and not on the contents of previously...... read cells. We study such non-adaptive data structures in the cell probe model. This model is one of the least restrictive lower bound models and in particular, cell probe lower bounds apply to data structures developed in the popular word-RAM model. Unfortunately, this generality comes at a high cost...

  3. Using Artificial Intelligence to Retrieve the Optimal Parameters and Structures of Adaptive Network-Based Fuzzy Inference System for Typhoon Precipitation Forecast Modeling

    Directory of Open Access Journals (Sweden)

    Chien-Lin Huang

    2015-01-01

    Full Text Available This study aims to construct a typhoon precipitation forecast model providing forecasts one to six hours in advance using optimal model parameters and structures retrieved from a combination of the adaptive network-based fuzzy inference system (ANFIS and artificial intelligence. To enhance the accuracy of the precipitation forecast, two structures were then used to establish the precipitation forecast model for a specific lead-time: a single-model structure and a dual-model hybrid structure where the forecast models of higher and lower precipitation were integrated. In order to rapidly, automatically, and accurately retrieve the optimal parameters and structures of the ANFIS-based precipitation forecast model, a tabu search was applied to identify the adjacent radius in subtractive clustering when constructing the ANFIS structure. The coupled structure was also employed to establish a precipitation forecast model across short and long lead-times in order to improve the accuracy of long-term precipitation forecasts. The study area is the Shimen Reservoir, and the analyzed period is from 2001 to 2009. Results showed that the optimal initial ANFIS parameters selected by the tabu search, combined with the dual-model hybrid method and the coupled structure, provided the favors in computation efficiency and high-reliability predictions in typhoon precipitation forecasts regarding short to long lead-time forecasting horizons.

  4. Effect of quick lime on physicochemical properties of clay soil

    Directory of Open Access Journals (Sweden)

    Bessaim Mohammed Mustapha

    2018-01-01

    Full Text Available Clay soils are known for their water sensitivity, which causes irreparable damage to any structure built on this type of soil. In order to avoid such problem, it is necessary to use various improvement and stabilization methods such as treatment with lime. This process has been used successfully in the field for decades. The addition of lime generates various physicochemical reactions within the soil such as cation exchange and pozzolanic reactions which are largely responsible for the improvement of the soil in question. This paper presents a study concerning the variation of physicochemical properties of clayey soil with the addition of quicklime at different percentages. Experiments were performed on two clayey soils (CL type in order to investigate the influence of quicklime on Atterberg limits and pH. These tests were carried out in an attempt to study and follow the development and progression of various reactions occurred within the soil with various lime percentages. The results show that the addition of quicklime causes a significant improvement in soil properties by reducing plasticity and thereby improves the soil workability. It can also be found that the addition of lime increase pH of soil, which allow activating pozzolanic reactions who tend to stabilize the soil in question by formation of cementitious compounds. Finally, the pH can be considered as a relevant parameter who allows a better understanding of the reactions that occur in the soil matrix.

  5. Improving drug candidates by design: a focus on physicochemical properties as a means of improving compound disposition and safety.

    Science.gov (United States)

    Meanwell, Nicholas A

    2011-09-19

    refinement, while deeper analyses have explored the correlation with metabolic stability and toxicity. These insights have been augmented by careful analyses of physicochemical aspects of drug-target interactions, with thermodynamic profiling indicating that the signature of best-in-class drugs is a dependence on enthalpy to drive binding energetics rather than entropy, which is dependent on lipophilicity. Optimization of the entropic contribution to the binding energy of a ligand to its target is generally much easier than refining the enthalpic element. Consequently, in the absence of a fundamental understanding of the thermodynamic complexion of an interaction, the design of molecules with increased lipophilicity becomes almost inevitable. The application of ligand efficiency, a measure of affinity per heavy atom, group efficiency, which assesses affinity in the context of structural changes, and lipophilic ligand efficiency, which relates potency to lipophilicity, offer less sophisticated but practically useful analytical algorithms to assess the quality of drug-target interactions. These parameters are readily calculated and can be applied to lead optimization programs in a fashion that helps to maximize potency while minimizing the kind of lipophilic burden that has been dubbed "molecular obesity". Several recently described lead optimization campaigns provide illustrative, informative, and productive examples of the effect of paying close attention to carefully controlling physicochemical properties by monitoring ligand efficiency and lipophilic ligand efficiency. However, to be successful during the lead optimization phase, drug candidate identification programs will need to adopt a holistic approach that integrates multiple parameters, many of which will have unique dependencies on both the drug target and the specific chemotype under prosecution. Nevertheless, there are many important drug targets that necessitate working in space beyond that which has been defined

  6. Crystal structure of a cold-active protease (Pro21717 from the psychrophilic bacterium, Pseudoalteromonas arctica PAMC 21717, at 1.4 Å resolution: Structural adaptations to cold and functional analysis of a laundry detergent enzyme.

    Directory of Open Access Journals (Sweden)

    Ha Ju Park

    Full Text Available Enzymes isolated from organisms found in cold habitats generally exhibit higher catalytic activity at low temperatures than their mesophilic homologs and are therefore known as cold-active enzymes. Cold-active proteases are very useful in a variety of biotechnological applications, particularly as active ingredients in laundry and dishwashing detergents, where they provide strong protein-degrading activity in cold water. We identified a cold-active protease (Pro21717 from a psychrophilic bacterium, Pseudoalteromonas arctica PAMC 21717, and determined the crystal structure of its catalytic domain (CD at a resolution of 1.4 Å. The Pro21717-CD structure shows a conserved subtilisin-like fold with a typical catalytic triad (Asp185, His244, and Ser425 and contains four calcium ions and three disulfide bonds. Interestingly, we observed an unexpected electron density at the substrate-binding site from a co-purified peptide. Although the sequence of this peptide is unknown, analysis of the peptide-complexed structure nonetheless provides some indication of the substrate recognition and binding mode of Pro21717. Moreover, various parameters, including a wide substrate pocket size, an abundant active-site loop content, and a flexible structure provide potential explanations for the cold-adapted properties of Pro21717. In conclusion, this is first structural characterization of a cold-adapted subtilisin-like protease, and these findings provide a structural and functional basis for industrial applications of Pro21717 as a cold-active laundry or dishwashing detergent enzyme.

  7. Crystal structure of a cold-active protease (Pro21717) from the psychrophilic bacterium, Pseudoalteromonas arctica PAMC 21717, at 1.4 Å resolution: Structural adaptations to cold and functional analysis of a laundry detergent enzyme.

    Science.gov (United States)

    Park, Ha Ju; Lee, Chang Woo; Kim, Dockyu; Do, Hackwon; Han, Se Jong; Kim, Jung Eun; Koo, Bon-Hun; Lee, Jun Hyuck; Yim, Joung Han

    2018-01-01

    Enzymes isolated from organisms found in cold habitats generally exhibit higher catalytic activity at low temperatures than their mesophilic homologs and are therefore known as cold-active enzymes. Cold-active proteases are very useful in a variety of biotechnological applications, particularly as active ingredients in laundry and dishwashing detergents, where they provide strong protein-degrading activity in cold water. We identified a cold-active protease (Pro21717) from a psychrophilic bacterium, Pseudoalteromonas arctica PAMC 21717, and determined the crystal structure of its catalytic domain (CD) at a resolution of 1.4 Å. The Pro21717-CD structure shows a conserved subtilisin-like fold with a typical catalytic triad (Asp185, His244, and Ser425) and contains four calcium ions and three disulfide bonds. Interestingly, we observed an unexpected electron density at the substrate-binding site from a co-purified peptide. Although the sequence of this peptide is unknown, analysis of the peptide-complexed structure nonetheless provides some indication of the substrate recognition and binding mode of Pro21717. Moreover, various parameters, including a wide substrate pocket size, an abundant active-site loop content, and a flexible structure provide potential explanations for the cold-adapted properties of Pro21717. In conclusion, this is first structural characterization of a cold-adapted subtilisin-like protease, and these findings provide a structural and functional basis for industrial applications of Pro21717 as a cold-active laundry or dishwashing detergent enzyme.

  8. Weld-bonding: a very well adapted joining technique to decrease the weight of steel structures; Le soudo-collage: une technique d'assemblage performante pour alleger les structures en acier

    Energy Technology Data Exchange (ETDEWEB)

    Charbonnet, Ph.; Clad, A.; Di Fant-Jaeckels, H.; Thirion, J.L. [Usinor RD, 92 - Puteaux (France)

    2000-04-01

    The association of spot welding and adhesive bonding, named weld-bonding, is a steel joining technique which increasingly interests car manufacturers. Nevertheless, weld-bonding is not at present used extensively by them due to a lack of data related to the performance of this technique. Studies carried out by Usinor have succeeded in demonstrating that weld-bonding is a very well adapted joining technique to decrease the weight of steel structures. (author)

  9. Soil Architecture and physicochemical functions

    DEFF Research Database (Denmark)

    de Jonge, Lis Wollesen; Møldrup, Per; Vendelboe, Anders Lindblad

    2012-01-01

    , and modeling of soil structure (architecture) and physical, chemical, and biological processes in different porous media systems and at different scales. Several studies in this special section also outline and discuss emerging and exciting interdisciplinary challenges for the rapidly growing vadose zone......Soils function as Earth's life support system, a thin layer full of life covering most of the terrestrial surfaces. Soils form the foundation of society. Norman Borlaug stated in his Nobel laureate lecture that “the first essential component of social justice is adequate food for all mankind.......” If we are to provide this component while sustaining environmental quality in the midst of a growing population and rapidly diminishing resources, it is imperative to study and obtain a deeper level of understanding of soil functions using state-of-the-art technologies as well as provide the next...

  10. Physicochemical and Sensorial Characterization of Honey Spirits.

    Science.gov (United States)

    Anjos, Ofélia; Frazão, David; Caldeira, Ilda

    2017-07-27

    Distilled spirits are usually made from fermented sugar-based materials, such as wines or fermented fruits, but other products can be used, namely berries or honey. In this work, an evaluation of honey spirits is done based on its physicochemical and sensory characteristics. Fourteen honey spirit samples of different brands of honey spirit were purchased at the market and from artisan Portuguese producers. Several analytical determinations, namely alcoholic strength, dry matter, density, total acidity, chromatic characteristics, methanol, acetaldehyde, ethyl acetate and higher alcohols were done to characterize all samples. The results pointed out several differences in physicochemical composition of samples. In general, these drinks are characterized by an alcohol strength between 37.4% and 53.0% and a low methanol content, quite null for most samples. Samples with higher ethanol content corresponded to the artisanal samples. Significant differences ( p drink, which has gained market value.

  11. Phase equilibria in the NaF-CdO-NaPO{sub 3} system at 873 K and crystal structure and physico-chemical characterizations of the new Na{sub 2}CdPO{sub 4}F fluorophosphate

    Energy Technology Data Exchange (ETDEWEB)

    Aboussatar, Mohamed [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); Mbarek, Aïcha [Laboratoire de Chimie Industrielle, Ecole Nationale d’Ingénieurs de Sfax, Université de Sfax, BP W3038, 3000 Sfax (Tunisia); Naili, Houcine [Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); El-Ghozzi, Malika [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Chadeyron, Geneviève [Université Clermont Auvergne, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS/UBP/SIGMA, BP 10448, F-63000 Clermont-Ferrand (France); Avignant, Daniel [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Zambon, Daniel, E-mail: Daniel.Zambon@univ-bpclermont.fr [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France)

    2017-04-15

    Isothermal sections of the diagram representing phase relationships in the NaF-CdO-NaPO{sub 3} system have been investigated by solid state reactions and powder X-ray diffraction. This phase diagram investigation confirms the polymorphism of the NaCdPO{sub 4} side component and the structure of the ß high temperature polymorph (orthorhombic, space group Pnma and unit cell parameters a=9.3118(2), b=7.0459(1), c=5.1849(1) Å has been refined. A new fluorophosphate, Na{sub 2}CdPO{sub 4}F, has been discovered and its crystal structure determined and refined from powder X-ray diffraction data. It exhibits a new 3D structure with orthorhombic symmetry, space group Pnma and unit cell parameters a=5.3731(1), b=6.8530(1), c=12.2691(2) Å. The structure is closely related to those of the high temperature polymorph of the nacaphite Na{sub 2}CaPO{sub 4}F and the fluorosilicate Ca{sub 2}NaSiO{sub 4}F but differs essentially in the cationic repartition since the structure is fully ordered with one Na site (8d) and one Cd site (4c). Relationships with other Na{sub 2}M{sup II}PO{sub 4}F (M{sup II}=Mg, Ca, Mn, Fe, Co, Ni) have been examined and the crystal-chemical and topographical analysis of these fluorophosphates is briefly reviewed. IR, Raman, optical and {sup 19}F, {sup 23}Na, {sup 31}P MAS NMR characterizations of Na{sub 2}CdPO{sub 4}F have been investigated. - Graphical abstract: The structure of the compound Na{sub 2}CdPO{sub 4}F, discovered during the study of the phase relationships in the NaF-CdO-NaPO{sub 3} system, has been determined and compared with other Na{sub 2}M{sup II}PO{sub 4}F fluorophosphates. - Highlights: • XRD analysis of the isothermal section of the NaF-CdO-NaPO{sub 3} system at 923 K. • Rietveld refinement of the high temperature polymorph β-NaCdPO{sub 4}. • Crystal structure of the new Na{sub 2}CdPO{sub 4}F fluorophosphate determined from powder XRD. • Crystal structure - composition relationships of Na{sub 2}M{sup II}PO{sub 4}F compounds

  12. Physicochemical properties of mixed phosphorus halides

    International Nuclear Information System (INIS)

    Sladkov, I.B.; Tugarinova, N.S.

    1996-01-01

    Certain physicochemical properties (thermodynamic characteristics at boiling point, critical constants, density of liquid on the saturation line) of mixed phosphorus halides (PI 3 , PI 2 F, PIF 2 , PI 2 Cl, PICl 2 , PI 1 Br, PIBr 2 , PIClF, PIBrCl, etc.) are determined by means of approximate methods. Reliability of the results obtained is confirmed by comparison of calculated and experimental data for phosphorus compounds of the same type. 7 refs., 3 figs., 4 tabs

  13. PHYSICOCHEMICAL CHARACTERIZATION OF COMPOST OF THE

    OpenAIRE

    MAHDI AHMED; AZNI IDRIS; S. R. SYED OMAR

    2007-01-01

    It is very important that tannery wastes in the form of sludge are managed in an environmentally sound manner. This study focused on the heavy metal characterization and the influence of changing the physico-chemical properties of the medium throughout the composting on the concentrations, bioavailability or chemical forms of Cr, Cu, Zn, Pb and Cd in tannery sludge. The physical and chemical properties of the composted sludge during treatment show the stability and maturity of end product. To...

  14. Assessment of Damage and Adaptation Strategies for Structures and Infrastructure from Storm Surge and Sea Level Rise for a Coastal Community in Rhode Island, United States

    Directory of Open Access Journals (Sweden)

    Christopher Small

    2016-10-01

    Full Text Available This paper presents an evaluation of inundation, erosion, and wave damage for a coastal community in Rhode Island, USA. A methodology called the Coastal Environmental Risk Index (CERI was used that incorporates levels of inundation including sea level rise, wave heights using STWAVE, and detailed information about individual structures from an E911 database. This information was input into damage functions developed by the U.S. Army Corps of Engineers following Hurricane Sandy. Damage from erosion was evaluated separately from local published erosion rates. Using CERI, two different adaptation strategies were evaluated that included a combination of dune restoration, protective berms, and a tide gate. A total of 151 out of 708 structures were estimated to be protected from inundation and wave action by the combined measures. More importantly, the use of CERI allowed for the assessment of the impact of different adaptation strategies on both individual structures and an entire community in a Geographical Information Systems (GIS environment. This tool shows promise for use by coastal managers to assess damage and mitigate risk to coastal communities.

  15. Adaptive Architectural Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Kirkegaard, Poul Henning

    2010-01-01

    Recent years have seen an increasing variety of applications of adaptive architectural structures for improvement of structural performance by recognizing changes in their environments and loads, adapting to meet goals, and using past events to improve future performance or maintain serviceability....... The general scopes of this paper are to develop a new adaptive kinetic architectural structure, particularly a reconfigurable architectural structure which can transform body shape from planar geometries to hyper-surfaces using different control strategies, i.e. a transformation into more than one or two...... different shape alternatives. The adaptive structure is a proposal for a responsive building envelope which is an idea of a first level operational framework for present and future investigations towards performance based responsive architectures through a set of responsive typologies. A mock- up concept...

  16. Physico-chemical standardization of Sitopaladi churna

    Science.gov (United States)

    Makhija, Inder Kumar; Shreedhara, Chandrashekara Shastry; Ram, Holavana Hally Nanjundaiah Setty Aswatha

    2012-01-01

    Background: Standardization of a compound Ayurvedic formulation is a critical and essential issue to be considered in assuring the therapeutic efficacy and safety and to rationalize their use in the health care. Sitopaladi churna is a reputed polyherbal formulation of Ayurveda. It is prescribed for the treatment of pleurodynia, intercostal neuralgia, cold, cough associated with bronchitis, pneumonia, tuberculosis, viral respiratory infection, and in pharyngeal and chest congestion. Objective: The present study aimed at physico-chemical standardization of in-house and two marketed brands of Sitopaladi churna. Materials and Methods: In our investigation, in-house churna and two commercial brands of Sitopaladi churna were standardized based on powder microscopy, physico-chemical evaluations, thin layer chromatography (TLC) and high performance thin layer chromatography (HPTLC) finger printing as per standard procedures. Results: The set parameters were sufficient to evaluate the churna based on various physico-chemical parameters. Conclusion: The data evolved can be adopted for laying down the standards for the manufacturing units of Sitopaladi churna. PMID:23284216

  17. Factor structure and reliability of the Italian adaptation of the Hypomania Check List-32, second revision (HCL-32-R2).

    Science.gov (United States)

    Fornaro, Michele; De Berardis, Domenico; Mazza, Monica; Pino, Mariachiara; Favaretto, Ettore; Bedani, Fulvio; Wieser, Christian; Indelicato, Luisa; Paternò, Vito Fabio; Lo Monaco, Francesca; Dugo, Febronia; Ventriglio, Antonio; Mungo, Sergio; Selle, Valerio; Valchera, Alessandro; Elassy, Mai; Martinotti, Giovanni; De Bartolomeis, Andrea; Iasevoli, Felice; Tomasetti, Carmine; Avvisati, Livia; Tartaglione, Sergio; Perna, Giampaolo; Cattaneo, Carlo Ignazio; Consoli, Giorgio; Romano, Anna; Del Debbio, Alessandro; Martino, Matteo; D' Angelo, Emanuela; De Pasquale, Concetta; Koshy, Ann Sarah; Angst, Jules

    2015-06-01

    To assess the psychometric properties of the Italian adaptation of the Hypomania-Check-List 32-item, second revision (HCL-32-R2) for the detection of bipolarity in major depressive disorder (MDD) treatment-seeking outpatients. A back-to-back Italian adaption of the "Bipolar Disorders: Improving Diagnosis, Guidance, and Education" English module of the HCL-32-R2 was administered between March 2013 and October 2014 across twelve collaborating sites in Italy. Diagnostic and Statistical Manual Fourth edition (DSM-IV) diagnoses were made adopting the mini-international neuropsychiatric interview, using bipolar disorder (BD) patients as controls. In our sample (n=441, of whom, BD-I=68; BD-II=117; MDD=256), using a cut-off of 14 allowed the HCL-32-R2 to discriminate DSM-IV-defined MDD patients between "true unipolar" (HCL-32-R2(-)) and "sub-threshold bipolar depression" (HCL-32-R2(+)) with sensitivity=89% and specificity=79%. Area under the curve was .888; positive and negative predictive values were 75.34% and 90.99% respectively. Owing to clinical interpretability considerations and consistency with previous adaptations of the HCL-32, a two-factor solution (F1="hyperactive/elated" vs. F2="irritable/distractible/impulsive") was preferred using exploratory and confirmatory factor analyses, whereas items n.33 ("I gamble more") and n.34 ("I eat more") introduced in the R2 version of the scale slightly loaded onto F2 and F1 respectively. Cronbach׳s α=.88 for F1 and .71 for F2. No cross-validation with any additional validated screening tool; treatment-seeking outpatient sample; recall bias; no systematic evaluation of eventual medical/psychiatric comorbidities, current/lifetime pharmacological history, neither record of severity of current MDE. Our results seem to indicate fair accuracy of HCL-32 as a screening instrument for BD, though replication studies are warranted. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Comparative morphology of the mouthparts of the megadiverse South African monkey beetles (Scarabaeidae: Hopliini: feeding adaptations and guild structure

    Directory of Open Access Journals (Sweden)

    Florian Karolyi

    2016-01-01

    Full Text Available Although anthophilous Coleoptera are regarded to be unspecialised flower-visiting insects, monkey beetles (Scarabaeidae: Hopliini represent one of the most important groups of pollinating insects in South Africa’s floristic hotspot of the Greater Cape Region. South African monkey beetles are known to feed on floral tissue; however, some species seem to specialise on pollen and/or nectar. The present study examined the mouthpart morphology and gut content of various hopliine species to draw conclusions on their feeding preferences. According to the specialisations of their mouthparts, the investigated species were classified into different feeding groups. Adaptations to pollen-feeding included a well-developed, toothed molar and a lobe-like, setose lacinia mobilis on the mandible as well as curled hairs or sclerotized teeth on the galea of the maxillae. Furthermore, elongated mouthparts were interpreted as adaptations for nectar feeding. Floral- and folial-tissue feeding species showed sclerotized teeth on the maxilla, but the lacinia was mostly found to be reduced to a sclerotized ledge. While species could clearly be identified as floral or folial tissue feeding, several species showed intermediate traits suggesting both pollen and nectar feeding adaptations. Mismatches found between mouthpart morphology and previously reported flower visiting behaviours across different genera and species requires alternative explanations, not necessarily associated with feeding preferences. Although detailed examinations of the mouthparts allowed conclusions about the feeding preference and flower-visiting behaviour, additional morphological and behavioural investigations, combined with greater taxon sampling and phylogenetic data, are still necessary to fully understand hopliine host plant relationships, related to monkey beetle diversity.

  19. Comparative morphology of the mouthparts of the megadiverse South African monkey beetles (Scarabaeidae: Hopliini): feeding adaptations and guild structure.

    Science.gov (United States)

    Karolyi, Florian; Hansal, Teresa; Krenn, Harald W; Colville, Jonathan F

    2016-01-01

    Although anthophilous Coleoptera are regarded to be unspecialised flower-visiting insects, monkey beetles (Scarabaeidae: Hopliini) represent one of the most important groups of pollinating insects in South Africa's floristic hotspot of the Greater Cape Region. South African monkey beetles are known to feed on floral tissue; however, some species seem to specialise on pollen and/or nectar. The present study examined the mouthpart morphology and gut content of various hopliine species to draw conclusions on their feeding preferences. According to the specialisations of their mouthparts, the investigated species were classified into different feeding groups. Adaptations to pollen-feeding included a well-developed, toothed molar and a lobe-like, setose lacinia mobilis on the mandible as well as curled hairs or sclerotized teeth on the galea of the maxillae. Furthermore, elongated mouthparts were interpreted as adaptations for nectar feeding. Floral- and folial-tissue feeding species showed sclerotized teeth on the maxilla, but the lacinia was mostly found to be reduced to a sclerotized ledge. While species could clearly be identified as floral or folial tissue feeding, several species showed intermediate traits suggesting both pollen and nectar feeding adaptations. Mismatches found between mouthpart morphology and previously reported flower visiting behaviours across different genera and species requires alternative explanations, not necessarily associated with feeding preferences. Although detailed examinations of the mouthparts allowed conclusions about the feeding preference and flower-visiting behaviour, additional morphological and behavioural investigations, combined with greater taxon sampling and phylogenetic data, are still necessary to fully understand hopliine host plant relationships, related to monkey beetle diversity.

  20. The rice OsNAC6 transcription factor orchestrates multiple molecular mechanisms involving root structural adaptions and nicotianamine biosynthesis for drought tolerance.

    Science.gov (United States)

    Lee, Dong-Keun; Chung, Pil Joong; Jeong, Jin Seo; Jang, Geupil; Bang, Seung Woon; Jung, Harin; Kim, Youn Shic; Ha, Sun-Hwa; Choi, Yang Do; Kim, Ju-Kon

    2017-06-01

    Drought has a serious impact on agriculture worldwide. A plant's ability to adapt to rhizosphere drought stress requires reprogramming of root growth and development. Although physiological studies have documented the root adaption for tolerance to the drought stress, underlying molecular mechanisms is still incomplete, which is essential for crop engineering. Here, we identified OsNAC6-mediated root structural adaptations, including increased root number and root diameter, which enhanced drought tolerance. Multiyear drought field tests demonstrated that the grain yield of OsNAC6 root-specific overexpressing transgenic rice lines was less affected by drought stress than were nontransgenic controls. Genome-wide analyses of loss- and gain-of-function mutants revealed that OsNAC6 up-regulates the expression of direct target genes involved in membrane modification, nicotianamine (NA) biosynthesis, glutathione relocation, 3'-phophoadenosine 5'-phosphosulphate accumulation and glycosylation, which represent multiple drought tolerance pathways. Moreover, overexpression of NICOTIANAMINE SYNTHASE genes, direct targets of OsNAC6, promoted the accumulation of the metal chelator NA and, consequently, drought tolerance. Collectively, OsNAC6 orchestrates novel molecular drought tolerance mechanisms and has potential for the biotechnological development of high-yielding crops under water-limiting conditions. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.