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Sample records for adjacent critical structures

  1. Precision, high dose radiotherapy. II. Helium ion treatment of tumors adjacent to critical central nervous system structures

    SciTech Connect

    Saunders, W.M.; Chen, G.T.Y.; Austin-Seymour, M.; Castro, J.R.; Collier, J.M.; Gauger, G.; Gutin, P.; Phillips, T.L.; Pitluck, S.; Walton, R.E.

    1985-07-01

    In this paper, the authors present a technique for treating relatively small, low grade tumors located very close to critical, radiation sensitive central nervous system structures such as the spinal cord and the brain stem. A beam of helium ions is used to irradiate the tumor. The nearby normal tissues are protected by exploiting the superb dose localization properties of this beam, particularly its well defined and controllable range in tissue, the increased dose deposited near the end of this range (i.e., the Bragg peak), the sharp decrease in dose beyond the Bragg peak, and the sharp penumbra of the beam. To illustrate the technique, the authors present a group of 19 patients treated for chordomas, meningiomas and low grade chondrosarcomas in the base of the skull or spinal column. They have been able to deliver high, uniform doses to the target volumes, while keeping the doses to the nearby critical tissues below the threshold for radiation damage. Follow-up on this group of patients is short, averaging 22 months (2 to 75 months). Currently, 15 patients have local control of their tumor. Two major complications, a spinal cord transsection and optic tract damage, are discussed in detail. Their treatment policies have been modified to minimize the risk of these complications in the future, and they are continuing to use this method to treat such patients.

  2. Compression of adjacent anatomical structures by pulmonary artery dilation.

    PubMed

    Dakkak, Wael; Tonelli, Adriano R

    2016-06-01

    Pulmonary hypertension is the commonest condition leading to dilated pulmonary artery. We describe three different types of compression of adjacent anatomical structures by dilated pulmonary arteries. We included involvement of the left main coronary artery, left recurrent laryngeal nerve and tracheobronchial tree. Compression of these structures can cause major complications such as myocardial ischemia, hoarseness and major airway stenosis. We present a case for each scenario and review the literature for each of these complications, focusing on patients' characteristics and contemporary management. PMID:26898826

  3. Structural Orientations Adjacent to Some Colorado Geothermal Systems

    DOE Data Explorer

    Richard,

    2012-02-01

    Citation Information: Originator: Geothermal Development Associates, Reno, Nevada Publication Date: 2012 Title: Structural Data Edition: First Publication Information: Publication Place: Reno Nevada Publisher: Geothermal Development Associates, Reno, Nevada Description: Structural orientations (fractures, joints, faults, lineaments, bedding orientations, etc.) were collected with a standard Brunton compass during routine field examinations of geothermal phenomena in Colorado. Often multiple orientations were taken from one outcrop. Care was taken to ensure outcrops were "in place". Point data was collected with a hand-held GPS unit. The structural data is presented both as standard quadrant measurements and in format suitable for ESRI symbology Spatial Domain: Extent: Top: 4491528.924999 m Left: 207137.983196 m Right: 432462.310324 m Bottom: 4117211.772001 m Contact Information: Contact Organization: Geothermal Development Associates, Reno, Nevada Contact Person: Richard “Rick” Zehner Address: 3740 Barron Way City: Reno State: NV Postal Code: 89511 Country: USA Contact Telephone: 775-737-7806 Spatial Reference Information: Coordinate System: Universal Transverse Mercator (UTM) WGS’1984 Zone 13N False Easting: 500000.00000000 False Northing: 0.00000000 Central Meridian: -105.00000000 Scale Factor: 0.99960000 Latitude of Origin: 0.00000000 Linear Unit: Meter Datum: World Geodetic System 1984 (WGS ’1984) Prime Meridian: Greenwich Angular Unit: Degree Digital Form: Format Name: Shape file

  4. Novel Method for Measuring Structure and Semantic Similarity of XML Documents Based on Extended Adjacency Matrix

    NASA Astrophysics Data System (ADS)

    Zhang, Xue-Liang; Yang, Ting; Fan, Bao-Quan; Wang, Xu; Wei, Jin-Mao

    Similarity measurement of XML documents is crucial to meet various needs of approximate searches and document classifications in XML-oriented applications. Some methods have been proposed for this purpose. Nevertheless, few methods can be elegantly exploited to depict structure and semantic information and hence to effectively measure the similarity of XML documents. In this paper, we present a new method of computing the structure and semantic similarity of XML documents based on extended adjacency matrix(EAM). Different from a general adjacency matrix, in an EAM, the structure information of not only the adjacent layers but also the ancestor-descendant layers can be stored. For measuring the similarity of two XML documents, the proposed method firstly stores the structure and semantic information in two extended adjacency matrices(M1, M2). Then it computes similarity of the two documents through cos(M1, M2) Experimental results on bench-mark data show that the method holds high efficiency and accuracy.

  5. Pounding Effects on the Earthquake Response of Adjacent Reinforced Concrete Structures Strengthened by Cable Elements

    NASA Astrophysics Data System (ADS)

    Liolios, Angelos; Liolios, Asterios; Hatzigeorgiou, George; Radev, Stefan

    2014-06-01

    A numerical approach for estimating the effects of pounding (seismic interaction) on the response of adjacent Civil Engineering structures is presented. Emphasis is given to reinforced concrete (RC) frames of existing buildings which are seismically strengthened by cable-elements. A double discretization, in space by the Finite Element Method and in time by a direct incremental approach is used. The unilateral behaviours of both, the cable-elements and the interfaces contact-constraints, are taken strictly into account and result to inequality constitutive conditions. So, in each time-step, a non-convex linear complementarity problem is solved. It is found that pounding and cable strengthening have significant effects on the earthquake response and, hence, on the seismic upgrading of existing adjacent RC structures.

  6. Shaking table experimentation on adjacent structures controlled by passive and semi-active MR dampers

    NASA Astrophysics Data System (ADS)

    Basili, M.; De Angelis, M.; Fraraccio, G.

    2013-06-01

    This paper presents the results of shaking table tests on adjacent structures controlled by passive and semi-active MR dampers. The aim was to demonstrate experimentally the effectiveness of passive and semi-active strategies in reducing structural vibrations due to seismic excitation. The physical model at issue was represented by two adjacent steel structures, respectively of 4 and 2 levels, connected at the second level by a MR damper. When the device operated in semi-active mode, an ON-OFF control algorithm, derived by the Lyapunov stability theory, was implemented and experimentally validated. Since the experimentation concerned adjacent structures, two control objectives have been reached: global and selective protection. In case of global protection, the attention was focused on protecting both structures, whereas, in case of selective protection, the attention was focused on protecting only one structure. For each objective the effectiveness of passive control has been compared with the situation of no control and then the effectiveness of semi-active control has been compared with the passive one. The quantities directly compared have been: measured displacements, accelerations and force-displacement of the MR damper, moreover some global response quantities have been estimated from experimental measures, which are the base share force and the base bending moment, the input energy and the energy dissipated by the device. In order to evaluate the effectiveness of the control action in both passive and semi-active case, an energy index EDI, previously defined and already often applied numerically, has been utilized. The aspects investigated in the experimentation have been: the implementation and validation of the control algorithm for selective and global protection, the MR damper input voltage influence, the kind of seismic input and its intensity.

  7. [Phytoplankton pigment patterns and community structure in the Yangtze Estuary and its adjacent areas].

    PubMed

    Lai, Jun-xiang; Yu, Zhi-ming; Song, Xiu-xian; Han, Xiao-tian; Cao, Xi-hua; Yuan, Yong-quan

    2013-09-01

    Three cruises were carried out in the Yangtze Estuary and its adjacent areas in May, November, June during 2009-2010. The spatial variations of phytoplankton community structure were investigated based on RP-HPLC analysis of pigments and CHEMTAX processing of the pigment data. 21 kinds of pigments were detected, among which chlorophyll a, peridinin, fucoxanthin, 19'-butanoyloxyfucoxanthin, 19'-hexanoyloxyfucoxanthin, chlorophyll b, diadinoxanthin, alloxanthin and zeaxanthin were the major pigments in the Yangtze Estuary and its adjacent areas. Chlorophyll a was the most abundant in all pigments, followed by fuxoxanthin. Other pigments generally contributed a minor proportion to the total pigments. High concentrations of fucoxanthin and peridinin were observed in May 2009 and June 2010, indicating blooms of diatoms and dinoflagellates. The results showed that the composition and distribution of phytoplankton pigments were influenced by environmental factors. The phytoplankton community, as determined by biomarker pigment concentration using HPLC and CHEMTAX, was composed mainly of diatoms, dinoflagellates, cryptophytes, chlorophytes, cyanobacteria, prymnesiophytes, chrysophytes and prasinophytes. The dominant algal groups were diatoms, dinoflagellates and chlorophytes in May 2009. The phytoplankton community was characterized by high contribution of diatoms in November 2009. Diatoms, dinoflagellates and cryptophytes accounted for 62.5% of chlorophyll a in June 2010, and the relative abundance of cyanobacteria was higher in this cruise. The spatial variations of phytoplankton community structure featured distinct regionality. Diatoms, chlorophytes and cryptophytes were the main groups in the inshore waters, and the abundances of prymnesiophytes, chrysophytes and cyanobacteria were increasing from inshore to the open sea. PMID:24288983

  8. Ambient seismic noise tomography of Canada and adjacent regions: Part I. Crustal structures

    NASA Astrophysics Data System (ADS)

    Kao, Honn; Behr, Yannik; Currie, Claire A.; Hyndman, Roy; Townend, John; Lin, Fan-Chi; Ritzwoller, Michael H.; Shan, Shao-Ju; He, Jiangheng

    2013-11-01

    paper presents the first continental-scale study of the crust and upper mantle shear velocity (Vs) structure of Canada and adjacent regions using ambient noise tomography. Continuous waveform data recorded between 2003 and 2009 with 788 broadband seismograph stations in Canada and adjacent regions were used in the analysis. The higher primary frequency band of the ambient noise provides better resolution of crustal structures than previous tomographic models based on earthquake waveforms. Prominent low velocity anomalies are observed at shallow depths (<20 km) beneath the Gulf of St. Lawrence in east Canada, the sedimentary basins of west Canada, and the Cordillera. In contrast, the Canadian Shield exhibits high crustal velocities. We characterize the crust-mantle transition in terms of not only its depth and velocity but also its sharpness, defined by its thickness and the amount of velocity increase. Considerable variations in the physical properties of the crust-mantle transition are observed across Canada. Positive correlations between the crustal thickness, Moho velocity, and the thickness of the transition are evident throughout most of the craton except near Hudson Bay where the uppermost mantle Vs is relatively low. Prominent vertical Vs gradients are observed in the midcrust beneath the Cordillera and beneath most of the Canadian Shield. The midcrust velocity contrast beneath the Cordillera may correspond to a detachment zone associated with high temperatures immediately beneath, whereas the large midcrust velocity gradient beneath the Canadian Shield probably represents an ancient rheological boundary between the upper and lower crust.

  9. SEISMIC RESPONSE PREDICTION OF NUPEC'S FIELD MODEL TESTS OF NPP STRUCTURES WITH ADJACENT BUILDING EFFECT.

    SciTech Connect

    XU,J.COSTANTINO,C.HOFMAYER,C.ALI,S.

    2004-03-04

    As part of a verification test program for seismic analysis computer codes for Nuclear Power Plant (NPP) structures, the Nuclear Power Engineering Corporation (NUPEC) of Japan has conducted a series of field model tests to address the dynamic cross interaction (DCI) effect on the seismic response of NPP structures built in close proximity to each other. The program provided field data to study the methodologies commonly associated with seismic analyses considering the DCI effect. As part of a collaborative program between the United States and Japan on seismic issues related to NPP applications, the U.S. Nuclear Regulatory Commission sponsored a program at Brookhaven National Laboratory (BNL) to perform independent seismic analyses which applied common analysis procedures to predict the building response to recorded earthquake events for the test models with DCI effect. In this study, two large-scale DCI test model configurations were analyzed: (1) twin reactor buildings in close proximity and (2) adjacent reactor and turbine buildings. This paper describes the NUPEC DCI test models, the BNL analysis using the SASSI 2000 program, and comparisons between the BNL analysis results and recorded field responses. To account for large variability in the soil properties, the conventional approach of computing seismic responses with the mean, mean plus and minus one-standard deviation soil profiles is adopted in the BNL analysis and the three sets of analysis results were used in the comparisons with the test data. A discussion is also provided in the paper to address (1) the capability of the analysis methods to capture the DCI effect, and (2) the conservatism of the practice for considering soil variability in seismic response analysis for adjacent NPP structures.

  10. Providing Structure: The Critical Element.

    ERIC Educational Resources Information Center

    Miller, Judith E.; And Others

    1996-01-01

    Discussion of course structure in active learning at the college level looks at ways level and type of structure can be varied and manipulated to meet challenges presented by a diverse student body. Issues discussed include the relationship of structure to cognitive style and development, fitting structure to content and objectives, and what can…

  11. Structural Priming: A Critical Review

    ERIC Educational Resources Information Center

    Pickering, Martin J.; Ferreira, Victor S.

    2008-01-01

    Repetition is a central phenomenon of behavior, and researchers have made extensive use of it to illuminate psychological functioning. In the language sciences, a ubiquitous form of such repetition is "structural priming," a tendency to repeat or better process a current sentence because of its structural similarity to a previously experienced…

  12. Structural Priming: A Critical Review

    PubMed Central

    Pickering, Martin J.; Ferreira, Victor S.

    2009-01-01

    Repetition is a central phenomenon of behavior, and researchers make extensive use of it to illuminate psychological functioning. In the language sciences, a ubiquitous form of such repetition is structural priming, a tendency to repeat or better process a current sentence because of its structural similarity to a previously experienced (“prime”) sentence (Bock, 1986). The recent explosion of research in structural priming has made it the dominant means of investigating the processes involved in the production (and increasingly, comprehension) of complex expressions such as sentences. This review considers its implications for the representation of syntax and the mechanisms of production, comprehension, and their relationship. It then addresses the potential functions of structural priming, before turning to its implications for first language acquisition, bilingualism, and aphasia We close with theoretical and empirical recommendations for future investigations. PMID:18444704

  13. Normal Variations of Sphenoid Sinus and the Adjacent Structures Detected in Cone Beam Computed Tomography

    PubMed Central

    Rahmati, Azadeh; Ghafari, Roshanak; AnjomShoa, Maryam

    2016-01-01

    Statement of the Problem The sphenoid sinus is a common target of paranasal surgery. Functional endoscopic sinus surgery is likely to endanger the anatomic variations of vital structures adjacent to the sphenoid sinus. Purpose The aim of this study was to determine the variations of sphenoid sinus and the related structures by using cone-beam computed tomography (CBCT). Materials and Method In this descriptive-analytic study, CBCT images of 103 patients aged above 20-years were selected (206 sides). Degree of pneumatization of sphenoid sinus, pneumatization of the anterior clinoid process, pterygoid process, protrusion of optic canal, vidian canal, and foramen rotundum, as well as prevalence of sinus septa were recorded. Examinations were performed using On-Demand software (Version 1); data were analyzed by using chi-square test. Results There was a statistically significant correlation between the pterygoid pneumatization and vidian canal protrusion (p< 0.001), and foramen rotundum protrusion (p< 0.001). The optic canal protrusion was found to be significantly associated with the anterior clinoid pneumatization and pterygoid process (p< 0.001). Statistically significant relationship was also observed between the carotid canal protrusion and pterygoid process pneumatization (p< 0.001). Conclusion The anatomical variations of the sphenoid sinus tend to give rise to a complexity of symptoms and potentially serious complications. This variability necessitates a comprehensive understanding of the regional sphenoid sinus anatomy by a detailed CBCT sinus examination. PMID:26966706

  14. Abundance and community structure of ammonia-oxidizing microorganisms in reservoir sediment and adjacent soils.

    PubMed

    Wang, Xiaoyan; Wang, Cui; Bao, Linlin; Xie, Shuguang

    2014-02-01

    Ammonia oxidation is an important process for global nitrogen cycling. Both ammonia-oxidizing bacteria (AOB) and archaea (AOA) can be the important players in nitrification process. However, their relative contribution to nitrification remains controversial. This study investigated the abundance and community structure of AOA and AOB in sediment of Miyun Reservoir and adjacent soils. Quantitative PCR assays indicated that the highest AOA abundance occurred in unplanted riparian soil, followed by reservoir sediment, reed-planted riparian soil and agricultural soil. The AOB community size in agricultural soil was much larger than that in the other habitats. Large variations in the structures of AOA and AOB were also observed among the different habitats. The abundance of Nitrosospira-like AOB species were detected in the agricultural soil and reservoir sediment. Pearson's correlation analysis showed the AOB diversity had positive significant correlations with pH and total nitrogen, while the AOA diversity might be negatively affected by nitrate nitrogen and ammonia nitrogen. This work could add new insights towards nitrification in aquatic and terrestrial ecosystems. PMID:23949998

  15. Effect of chromated copper arsenate structures on adjacent soil arsenic concentrations.

    PubMed

    Patch, Steven C; Scheip, Katherine; Brooks, Billy

    2011-06-01

    Structures made of chromated copper arsenic (CCA) have been shown to leach arsenic into the surrounding soil. Soil cores were taken adjacent to six CCA decks at 0, 15, 60 and 300 cm from the deck at depths of 0-10, 10-20, and 20-30 cm, and were analyzed for soil arsenic concentrations. Median soil arsenic concentrations ranged from 1.8 μg/g at a depth of 10-20 cm and a distance of 300 cm to 34.5 μg/g at a depth of 0-10 cm and a distance of 30 cm. Soil arsenic concentrations taken at depths of 0-10 and 10-20 cm decreased as distance from the deck increased. Soil arsenic concentrations close to the deck were higher at lower soil depths and at homes with greater deck wipe arsenic concentrations. Age of deck and slope of land had significant effects on the differences in arsenic concentrations between samples taken at different distances when evaluated in models by themselves, but not in models adjusting for deck wipe concentrations. Size of deck and bulk density of soil did not have significant effects on soil arsenic concentrations. PMID:21505794

  16. Crustal Structure of the Ethiopian Rift and Adjacent Plateaus: Results of new integrated interpretation

    NASA Astrophysics Data System (ADS)

    Tadesse, K.; Keller, G. R.

    2006-12-01

    The Ethiopian rift is the large part of the East African Rift system, which represents an incipient divergent plate boundary. This important structure provides excellent opportunities to study the transition from continental to oceanic. As a result, geophysical data are becoming increasingly available but some results are contradictory. We used a newly enhanced gravity database and seismic information to produce an integrated interpretation of the crustal structure beneath the Ethiopian rift and the adjacent plateaus. Wide regions have been covered to assess the regional structures including the Kenyan and Ethiopian rifts and the area covered by the Ethiopian flood basalt. Broad negative Bouguer gravity anomalies are delineated over the Ethiopian Plateaus and the Kenyan dome. Residual gravity anomalies, which parallel the major border faults clearly highlight the segregation between the plateaus and the rift valleys. Results of other filtering techniques have clearly revealed individual volcanic centers within the rift valleys. Positive gravity anomalies outside the rift valleys may be associated with older structures, shield volcanoes, or structures that are related to the initiation and propagation of rifting. A long axial profile from the central part of Kenya to the Afar triple junction has been modeled to investigate along-axis crustal variation of the East African rift system, with emphasis on the Ethiopian rift. This modeling has been constrained using seismic refraction data from the Ethiopian Afar Geoscientific Lithospheric Experiment (EAGLE) and Kenya Rift International Seismic Project (KRISP) results. We are able to see a thin crust (~26 km) in the Afar triangle with a gradual thickening (~40 km) southwards towards the Main Central Ethiopian rift (MER). The crust thickness decreases towards Turkana rift (~22 km), and increases again towards the central eastern rift section in Kenya. Our profile model across the MER has revealed that the eastern rift

  17. Basement structures of East and South China Seas and adjacent regions from gravity inversion

    NASA Astrophysics Data System (ADS)

    Guan, Dongliang; Ke, Xiaoping; Wang, Yong

    2016-03-01

    The satellite-derived gravity gives us an opportunity to investigate the basement structures of the East and South China Seas since the satellite gravimetry could provide large scale gravity data with high resolution of 1 arc-min by 1 arc-min. We isolate the residual gravity anomaly corresponding to the basement by subtracting the gravity anomalies of sediments and Moho undulations from satellite-derived free-air gravity anomalies. Two methods, namely gravity inversion method and convolution method based on flexure isostasy model, are used to calculate the Moho undulations in order to guarantee the accuracy of the Moho undulations since it occupies large percentages of the gravity anomalies. We invert the isolated gravity anomaly for the basement depths of East and South China Seas and adjacent areas with resolution of 1 arc-min by 1 arc-min. The basement depths of East and South China Seas range from 0.5 km to 12 km and the Moho depths vary between 6 km and 32 km. The basement topography reveals many tectonic depressions and two spreading axes concealed by the sediments, which are unseen in the bathymetry. The two spreading axes correspond to the spreading ridges derived from magnetic anomaly and the SW-NE oriented spreading axis extends SW much farther than that identified from magnetic anomaly, almost reaching to the Nam Con Son Basin. We also find that the faults constrain the distributions of basement depressions since the faults usually lie along the places where large changes of basement depth take place. Reversely, the basement map could be used to identify the unknown faults. Besides, according to the four profiles in the East and South China Seas, the mirror-image relation was found between the basement topography and the underlying Moho undulations that when the basement depth increases or decreases, the corresponding Moho depth decreases or increases.

  18. Structure of phytoplankton communities in the Yenisei estuary and over the adjacent Kara Sea shelf

    NASA Astrophysics Data System (ADS)

    Sukhanova, I. N.; Flint, M. V.; Sergeeva, V. M.; Druzhkova, E. I.; Nedospasov, A. A.

    2015-11-01

    Material was collected in the Yenisei estuary and over the adjacent Kara Sea shelf at a quasimeridional transect from 71°49'70″ to 75°59'93″ N in September 2011. The structural characteristics of the phytoplankton community were determined by latitudinal zonality of environmental conditions. Two well-distinguished phytocenoses—freshwater and marine—were found in this region. Phytoplankton in the freshwater part of the estuary was composed solely of the freshwater algae species and was distinguished by the highest numbers (up to 2 × 106 cell/L) and biomass (up to 1.4 mg/L). The marine phytocenoses over the Yenisei shoal was composed of marine neritic species; the abundance and biomass of phytoplankton in this area were significantly lower (0.2 × 106 cell/L and 0.4 mg/L, respectively). The area of intensive interaction of riverine and marine waters—the estuarine frontal zone, with ~130 km latitudinal extension (from 72° to 74° N)—was characterized by a sharp halocline, which separated the desalinated upper layer from the underlying marine water. Freshwater algal species predominated above the halocline, whereas marine species predominated below. The lower border of the euphotic layer was located 8 to 15 m below the halocline. The niche between the halocline and the lower border of the euphotic layer was characterized by high nutrient concentrations, which together with sufficient illumination determined the intensive development of phytoplankton and high values of primary production.

  19. On the Adjacency Matrix of RyR2 Cluster Structures.

    PubMed

    Walker, Mark A; Kohl, Tobias; Lehnart, Stephan E; Greenstein, Joseph L; Lederer, W J; Winslow, Raimond L

    2015-11-01

    In the heart, electrical stimulation of cardiac myocytes increases the open probability of sarcolemmal voltage-sensitive Ca2+ channels and flux of Ca2+ into the cells. This increases Ca2+ binding to ligand-gated channels known as ryanodine receptors (RyR2). Their openings cause cell-wide release of Ca2+, which in turn causes muscle contraction and the generation of the mechanical force required to pump blood. In resting myocytes, RyR2s can also open spontaneously giving rise to spatially-confined Ca2+ release events known as "sparks." RyR2s are organized in a lattice to form clusters in the junctional sarcoplasmic reticulum membrane. Our recent work has shown that the spatial arrangement of RyR2s within clusters strongly influences the frequency of Ca2+ sparks. We showed that the probability of a Ca2+ spark occurring when a single RyR2 in the cluster opens spontaneously can be predicted from the precise spatial arrangements of the RyR2s. Thus, "function" follows from "structure." This probability is related to the maximum eigenvalue (λ1) of the adjacency matrix of the RyR2 cluster lattice. In this work, we develop a theoretical framework for understanding this relationship. We present a stochastic contact network model of the Ca2+ spark initiation process. We show that λ1 determines a stability threshold for the formation of Ca2+ sparks in terms of the RyR2 gating transition rates. We recapitulate these results by applying the model to realistic RyR2 cluster structures informed by super-resolution stimulated emission depletion (STED) microscopy. Eigendecomposition of the linearized mean-field contact network model reveals functional subdomains within RyR2 clusters with distinct sensitivities to Ca2+. This work provides novel perspectives on the cardiac Ca2+ release process and a general method for inferring the functional properties of transmembrane receptor clusters from their structure. PMID:26545234

  20. On the Adjacency Matrix of RyR2 Cluster Structures

    PubMed Central

    Walker, Mark A.; Kohl, Tobias; Lehnart, Stephan E.; Greenstein, Joseph L.; Lederer, W. J.; Winslow, Raimond L.

    2015-01-01

    In the heart, electrical stimulation of cardiac myocytes increases the open probability of sarcolemmal voltage-sensitive Ca2+ channels and flux of Ca2+ into the cells. This increases Ca2+ binding to ligand-gated channels known as ryanodine receptors (RyR2). Their openings cause cell-wide release of Ca2+, which in turn causes muscle contraction and the generation of the mechanical force required to pump blood. In resting myocytes, RyR2s can also open spontaneously giving rise to spatially-confined Ca2+ release events known as “sparks.” RyR2s are organized in a lattice to form clusters in the junctional sarcoplasmic reticulum membrane. Our recent work has shown that the spatial arrangement of RyR2s within clusters strongly influences the frequency of Ca2+ sparks. We showed that the probability of a Ca2+ spark occurring when a single RyR2 in the cluster opens spontaneously can be predicted from the precise spatial arrangements of the RyR2s. Thus, “function” follows from “structure.” This probability is related to the maximum eigenvalue (λ1) of the adjacency matrix of the RyR2 cluster lattice. In this work, we develop a theoretical framework for understanding this relationship. We present a stochastic contact network model of the Ca2+ spark initiation process. We show that λ1 determines a stability threshold for the formation of Ca2+ sparks in terms of the RyR2 gating transition rates. We recapitulate these results by applying the model to realistic RyR2 cluster structures informed by super-resolution stimulated emission depletion (STED) microscopy. Eigendecomposition of the linearized mean-field contact network model reveals functional subdomains within RyR2 clusters with distinct sensitivities to Ca2+. This work provides novel perspectives on the cardiac Ca2+ release process and a general method for inferring the functional properties of transmembrane receptor clusters from their structure. PMID:26545234

  1. Structural determinants of criticality in biological networks

    PubMed Central

    Valverde, Sergi; Ohse, Sebastian; Turalska, Malgorzata; West, Bruce J.; Garcia-Ojalvo, Jordi

    2015-01-01

    Many adaptive evolutionary systems display spatial and temporal features, such as long-range correlations, typically associated with the critical point of a phase transition in statistical physics. Empirical and theoretical studies suggest that operating near criticality enhances the functionality of biological networks, such as brain and gene networks, in terms for instance of information processing, robustness, and evolvability. While previous studies have explained criticality with specific system features, we still lack a general theory of critical behavior in biological systems. Here we look at this problem from the complex systems perspective, since in principle all critical biological circuits have in common the fact that their internal organization can be described as a complex network. An important question is how self-similar structure influences self-similar dynamics. Modularity and heterogeneity, for instance, affect the location of critical points and can be used to tune the system toward criticality. We review and discuss recent studies on the criticality of neuronal and genetic networks, and discuss the implications of network theory when assessing the evolutionary features of criticality. PMID:26005422

  2. Heat flow distribution and thermal structure of the Philippine Sea Plate and its adjacent areas

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Chen, C.; Liang, Q.; Sun, S.

    2013-12-01

    Research on the present geothermal state is an important way to understand the lithospheric geodynamics. We studied the heat flow (HF) distribution and the geothermal structure of the Philippine Sea Plate (PSP) and its adjacent area (100°E~155°E, 5°S~45°N) surrounded by the East China Sea, South China Sea and the West Pacific Ocean, which is aimed to provide thermal constraints for the dynamic mechanism and tectonic evolution of the PSP. Based on the observed seafloor HF data of the study area with the latest release of CRUST1.0 crustal layered model, the lithospheric geotherm was calculated using 1D steady-state heat conduction equation. However, the obtained numerous geotherms derived from the extrapolation through heat conduction equation strongly depended on the accuracy of the measured HF data, which is limited, unevenly distributed and easily affected by local factors. Therefore, as a meaningful comparison, the temperature distributions at 25 km and 50 km depth inferred from the upper mantle shear wave velocities structure (S2.9EA) are inverted. The HF distribution shows relatively high values in Ryuku Trench and nearby Izu-Boning Trench, where the crust thicken and the mantle uplift obviously as typical transition zones. The Mariana Trench located in the east (southeast) part and the Philippine Trench in the southwest both are with low HF, which is also illustrated in the upper mantle gravity map after temperature correction. The Central Basin Ridge is with unquestionable high HF, being perpendicular to which the value decreasing. The calculated temperature maps (at depth of 25 km and 50 km) by the two methods both present that the temperature in PSP is higher than that in the Western Pacific Ocean and the west Philippine Basin is lower than the east one, which consists well with the crust age. The west half parts both of the Philippine Basin and Parece Vela Basin show low temperature, but high value in Ryuku Trench, Nankai Through, Shikoku Basin, Amami

  3. A Giant Retroperitoneal Liposarcoma Encasing the Entire Left Kidney and Adherent to Adjacent Structures: A Case Report

    PubMed Central

    Oh, Sung Don; Oh, Sung Jin; Suh, Byoung Jo; Shin, Jin Yong; Oh, Cheol Kyu; Park, Jong Kwon; Kim, Yeon Mee; Kim, Bo Mi

    2016-01-01

    Retroperitoneal liposarcoma is a rare tumor. The dimension and weight of liposarcoma are variable; those over 20 kg are called ‘giant liposarcoma’. Herein, we report giant retroperitoneal liposarcoma measuring 45 cm in diameter and 25 kg in weight encasing the entire left kidney and adherent to adjacent structures. A 71-year-old woman presented for a regular checkup. Image study revealed a huge mass probably indicative of retroperitoneal liposarcoma encasing the entire left kidney and adherent to adjacent structures. We performed an organ-preserving surgical removal. The pathologic report was liposarcoma. At postoperative month 16, a follow-up CT revealed a locally recurrent tumor. The patient underwent surgical removal of the newly discovered mass. After the second surgery, the patient underwent regular follow-up CT for approximately 12 months, and to date, there has been no evidence of tumor recurrence. High-grade liposarcoma shows sensitivity to radiation therapy. However, the toxic effect of radiation therapy limits this option by treatment modality. The use of chemotherapy is also controversial. As a result, complete resection is the gold standard treatment. Here, we report a giant retroperitoneal liposarcoma encasing the entire left kidney and adherent to adjacent structures, describe successful organ-preserving surgical removal and discuss prognosis. PMID:27462239

  4. Meroplankton spatial structure and variability on Abrolhos Bank and adjacent areas, with emphasis on brachyuran larvae

    NASA Astrophysics Data System (ADS)

    Koettker, Andréa Green; Lopes, Rubens M.

    2013-11-01

    The spatial distribution of meroplanktonic stages of benthic invertebrates was investigated on the Abrolhos Bank and adjacent shelf and oceanic areas during winter. Meroplanktonic larvae occurred at all stations, with higher total density in shallow sites, the same being observed for eight out of 14 taxonomic groups identified, including brachyurans. Brachyuran larvae were analyzed in detail, leading to a list of 61 taxa for the area, 24 of which accounted for half of the total brachyuran larval density. No estuarine species of brachyuran larvae was recorded in the surveyed area, suggesting that continental input from nearby river estuaries is negligible on the shelf ecosystem. Larvae of coastal species, such as Acantholobulus schmitti, Hexapanopeus spp. and Pinnixa sayana dominated at certain innermost stations and were not found on the outer shelf, suggesting the existence of larval retention mechanisms within the reef system. The occurrence of a single cluster of shallow stations in ordination analysis, associated with high densities of early developmental stages throughout the Abrolhos Bank, indicates a relatively homogeneous distribution of larval assemblages over the bank and the existence of a certain degree of connectivity among spatially separated populations, by means of larval dispersion.

  5. Hybrid control approach for seismic coupling of two similar adjacent structures

    NASA Astrophysics Data System (ADS)

    Park, Kwan-Soon; Ok, Seung-Yong

    2015-08-01

    This study describes an optimal hybrid control approach of two similar adjacent buildings for seismic performance improvement, for which the passive dampers are used as link members between the two parallel buildings and the active control devices are installed as tendon-type devices between two successive floors in the buildings. Throughout this configuration, the passive coupling dampers modulate the relative responses between the two buildings and the active control devices modulate the inter-story responses of each building. In order to achieve global optimal control performance, genetic algorithm is employed to perform an integrated design approach for the system of buildings and hybrid control devices. Through the optimization process, the passive and active devices are optimally distributed along the floors and, simultaneously, their damping capacities and active controllers are configured in accordance with the distribution. The proposed approach is demonstrated in comparison with typical active control system which consists of two independent active systems without any connections between two buildings, each being optimal for one particular building. The numerical simulation results for a system of 20-story and 16-story buildings reveal that the proposed system can guarantee the competent control performance over the typical independent active system with less control forces and powers. As a result, it is proved that the proposed approach enables the simultaneous optimization of the control performance and the control cost.

  6. Temporal distribution of bacterial community structure in the Changjiang Estuary hypoxia area and the adjacent East China Sea

    NASA Astrophysics Data System (ADS)

    Liu, Min; Xiao, Tian; Wu, Ying; Zhou, Feng; Huang, Huiqin; Bao, Shixiang; Zhang, Wuchang

    2012-06-01

    Bacterial community structure and the effects of environmental factors on the microbial community distribution were investigated in the Changjiang Estuary hypoxia area and its adjacent area in the East China Sea (ECS) in June, August and October, 2006. Profiles of bacterial communities were generated by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes followed by DNA sequence analysis. The dominant bacterial groups were affiliated to Gammaproteobacteria, Cytophaga-Flavobacteria-Bacteroides (CFB), Deltaproteobacteria, Cyanobacteria and Firmicutes, which were mostly from the marine seawater ecosystem. Effects of environmental factors on the bacterial community distribution were analyzed by the ordination technique of canonical correspondence analysis (CCA). The environmental factors significantly influencing bacterial community structure were different in the three months; dissolved organic carbon (DOC) and temperature in June and nitrite in August. No environmental variables displayed significant influence on the bacterial community at the 5% level in October. The seasonal environmental heterogeneity in the Changjiang Estuary and the adjacent ECS, such as seasonal hydrodynamic conditions and riverine input of nutrients, might be the reason for the difference in the key environmental factors determining the bacterial community in the three months.

  7. Structural character of Hosgri fault zone and adjacent areas in offshore central California

    SciTech Connect

    Crouch, J.K.; Bachman, S.B.

    1987-05-01

    The Hosgri fault zone extends from the east-west Transverse Ranges structures near Point Arguello northward for more than 150 km to the offshore area near San Simeon Point. The fault zone is seismically active and consists chiefly of a continuous series of eastside-up thrust and high-angle reverse faults. East of the fault zone, Miocene Monterey and volcanic rocks, along with underlying pre-Miocene strata, have been tightly folded as a result of low-angle imbricate thrust faulting during post-Miocene time. These highly deformed strata have been uplited and truncated along the inner shelf. Immediately west of the Hosgria fault zone, similar Monterey and older rocks, which are less folded, conformably underlie Pliocene and younger basinal strata at structural levels that are generally 1200 to 2000 m deeper than correlative strata east of the Hosgri fault zone. Following its discovery in 1971, the Hosgri fault zone was characterized by subsequent investigators as a northwest-trending fault that was part of the San Andreas system of strike-slip faults, with disagreements on the timing and amount of right-lateral offset along the fault zone. However, modern offshore seismic-reflection data, earthquake focal-mechanism studies, and recently available offshore well information suggest that the Hosgri fault zone is instead a major imbricate thrust zone. Detailed structural analyses along part of the Hosgri fault zone suggest that little, if any, strike-slip offset has occurred along this structural trend since its post-Miocene inception. Nevertheless, the Hosgri fault zone itself can be interpreted to be a product of the larger overall San Andreas transform system in that compression has developed because the San Andreas is not parallel to the Pacific-North American plate motion.

  8. Computer-generated holography enhances voltage dye fluorescence discrimination in adjacent neuronal structures

    PubMed Central

    Foust, Amanda J.; Zampini, Valeria; Tanese, Dimitrii; Papagiakoumou, Eirini; Emiliani, Valentina

    2015-01-01

    Abstract. Voltage-sensitive fluorescence indicators enable tracking neuronal electrical signals simultaneously in multiple neurons or neuronal subcompartments difficult to access with patch electrodes. However, efficient widefield epifluorescence detection of rapid voltage fluorescence transients necessitates that imaged cells and structures lie sufficiently far from other labeled structures to avoid contamination from out of focal plane and scattered light. We overcame this limitation by exciting dye fluorescence with one-photon computer-generated holography shapes contoured to axons or dendrites of interest, enabling widefield detection of voltage fluorescence with high spatial specificity. By shaping light onto neighboring axons and dendrites, we observed that dendritic back-propagating action potentials were broader and slowly rising compared with axonal action potentials, differences not measured in the same structures illuminated with a large “pseudowidefield” (pWF) spot of the same excitation density. Shaped illumination trials showed reduced baseline fluorescence, higher baseline noise, and fractional fluorescence transient amplitudes two times greater than trials acquired with pWF illumination of the same regions. PMID:26157998

  9. Computer-generated holography enhances voltage dye fluorescence discrimination in adjacent neuronal structures.

    PubMed

    Foust, Amanda J; Zampini, Valeria; Tanese, Dimitrii; Papagiakoumou, Eirini; Emiliani, Valentina

    2015-04-01

    Voltage-sensitive fluorescence indicators enable tracking neuronal electrical signals simultaneously in multiple neurons or neuronal subcompartments difficult to access with patch electrodes. However, efficient widefield epifluorescence detection of rapid voltage fluorescence transients necessitates that imaged cells and structures lie sufficiently far from other labeled structures to avoid contamination from out of focal plane and scattered light. We overcame this limitation by exciting dye fluorescence with one-photon computer-generated holography shapes contoured to axons or dendrites of interest, enabling widefield detection of voltage fluorescence with high spatial specificity. By shaping light onto neighboring axons and dendrites, we observed that dendritic back-propagating action potentials were broader and slowly rising compared with axonal action potentials, differences not measured in the same structures illuminated with a large "pseudowidefield" (pWF) spot of the same excitation density. Shaped illumination trials showed reduced baseline fluorescence, higher baseline noise, and fractional fluorescence transient amplitudes two times greater than trials acquired with pWF illumination of the same regions. PMID:26157998

  10. Contrast-enhanced X-ray microtomography of the bone structure adjacent to oral implants

    NASA Astrophysics Data System (ADS)

    Tesei, L.; Casseler, F.; Dreossi, D.; Mancini, L.; Tromba, G.; Zanini, F.

    2005-08-01

    One of the most important aims about cortical and cancellous bone research is to understand the factors that determine their mechanical properties, how these properties are maintained, and how bone reacts to changes in its environment, such as the introduction of a titanium implant. Trabecular morphometry has been traditionally assessed in two dimensions, where the structural parameters are either inspected visually or measured from sections, and the third dimension is added on the basis of stereology. Particularly, limiting is the destructive nature of this extremely time consuming procedure, preventing the specimens from being used for other measurements. The most common technique used to overcome some of the limitations of two-dimensional analysis is stereo- or scanning microscopy to assess three-dimensional structural indices qualitatively. Synchrotron radiation X-ray computed microtomography is a particular kind of X-ray computerized axial tomography with higher resolution and the possibility to choose among a very wide range of X-ray energies. Beam energies ranging between 30 and 40 keV will provide a satisfactory signal-to-noise ratio and contrast for bone, except for the parts falling in the shadow of the Ti implant. Higher beam energies would provide correctly exposed images, with lower -to noise ratio for the bone trabecular structure. We will show how the use of alternative materials, such as aluminum, while not altering the evaluation of the mechanical impact of an implant, allows a satisfactory non-destructive, three-dimensional analysis of the bone-implant interface.

  11. Cations Stiffen Actin Filaments by Adhering a Key Structural Element to Adjacent Subunits.

    PubMed

    Hocky, Glen M; Baker, Joseph L; Bradley, Michael J; Sinitskiy, Anton V; De La Cruz, Enrique M; Voth, Gregory A

    2016-05-26

    Ions regulate the assembly and mechanical properties of actin filaments. Recent work using structural bioinformatics and site-specific mutagenesis favors the existence of two discrete and specific divalent cation binding sites on actin filaments, positioned in the long axis between actin subunits. Cation binding at one site drives polymerization, while the other modulates filament stiffness and plays a role in filament severing by the regulatory protein, cofilin. Existing structural methods have not been able to resolve filament-associated cations, and so in this work we turn to molecular dynamics simulations to suggest a candidate binding pocket geometry for each site and to elucidate the mechanism by which occupancy of the "stiffness site" affects filament mechanical properties. Incorporating a magnesium ion in the "polymerization site" does not seem to require any large-scale change to an actin subunit's conformation. Binding of a magnesium ion in the "stiffness site" adheres the actin DNase-binding loop (D-loop) to its long-axis neighbor, which increases the filament torsional stiffness and bending persistence length. Our analysis shows that bound D-loops occupy a smaller region of accessible conformational space. Cation occupancy buries key conserved residues of the D-loop, restricting accessibility to regulatory proteins and enzymes that target these amino acids. PMID:27146246

  12. Gravity anomaly and crustal density structure in Jilantai rift zone and its adjacent region

    NASA Astrophysics Data System (ADS)

    Wu, Guiju; Shen, Chongyang; Tan, Hongbo; Yang, Guangliang

    2016-08-01

    This paper deals with the interpretation of Bouguer gravity anomalies measured along a 250 km long Suhaitu-Etuokeqi gravity profile located at the transitional zone of the Alxa and Ordos blocks where geophysical characteristics are very complex. The analysis is carried out in terms of the ratio of elevation and Bouguer gravity anomaly, the normalized full gradient of a section of the Bouguer gravity anomaly (G h ) and the crustal density structure reveal that (1) the ratio of highs and lows of elevation and Bouguer gravity anomaly is large between Zhengyiguan fault (F4) and Helandonglu fault (F6), which can be explained due to crustal inhomogeneities related to the uplift of the Qinghai-Tibet block in the northeast; (2) the main active faults correspond to the G h contour strip or cut the local region, and generally show strong deformation characteristics, for example the Bayanwulashan mountain front fault (F1) or the southeast boundary of Alxa block is in accord with the western change belt of G h , a belt about 10 km wide that extends to about 30 km; (3) Yinchuan-Pingluo fault (F8) is the seismogenic structure of the Pingluo M earthquake, and its focal depth is about 15 km; (4) the Moho depth trend and Bouguer gravity anomaly variation indicates that the regional gravity field is strongly correlated with the Moho discontinuity.

  13. Structures and Energetics of Four Adjacent G·U Pairs That Stabilize an RNA Helix.

    PubMed

    Gu, Xiaobo; Mooers, Blaine H M; Thomas, Leonard M; Malone, Joshua; Harris, Steven; Schroeder, Susan J

    2015-10-22

    Consecutive G·U base pairs inside RNA helices can be destabilizing, while those at the ends of helices are thermodynamically stabilizing. To determine if this paradox could be explained by differences in base stacking, we determined the high-resolution (1.32 Å) crystal structure of (5'-GGUGGCUGUU-3')2 and studied three sequences with four consecutive terminal G·U pairs by NMR spectroscopy. In the crystal structure of (5'-GGUGGCUGUU-3')2, the helix is overwound but retains the overall features of A-form RNA. The penultimate base steps at each end of the helix have high base overlap and contribute to the unexpectedly favorable energetic contribution for the 5'-GU-3'/3'-UG-5' motif in this helix position. The balance of base stacking and helical twist contributes to the positional dependence of G·U pair stabilities. The energetic stabilities and similarity to A-form RNA helices suggest that consecutive G·U pairs would be recognized by RNA helix binding proteins, such as Dicer and Ago. Thus, these results will aid future searches for target sites of small RNAs in gene regulation. PMID:26425937

  14. Advocating for a More Effective Critical Pedagogy by Examining Structural Obstacles to Critical Educational Reform

    ERIC Educational Resources Information Center

    Neumann, Jacob W.

    2013-01-01

    Since a major purpose of critical pedagogy is to change society by changing schools, critical pedagogy must gain an increased presence within K-12 schools. For this to happen, however, critical educators must begin to more fully recognize and appreciate the structural obstacles that schools present to critical educational change. This paper…

  15. Critical joints in large composite aircraft structure

    NASA Technical Reports Server (NTRS)

    Nelson, W. D.; Bunin, B. L.; Hart-Smith, L. J.

    1983-01-01

    A program was conducted at Douglas Aircraft Company to develop the technology for critical structural joints of composite wing structure that meets design requirements for a 1990 commercial transport aircraft. The prime objective of the program was to demonstrate the ability to reliably predict the strength of large bolted composite joints. Ancillary testing of 180 specimens generated data on strength and load-deflection characteristics which provided input to the joint analysis. Load-sharing between fasteners in multirow bolted joints was computed by the nonlinear analysis program A4EJ. This program was used to predict strengths of 20 additional large subcomponents representing strips from a wing root chordwise splice. In most cases, the predictions were accurate to within a few percent of the test results. In some cases, the observed mode of failure was different than anticipated. The highlight of the subcomponent testing was the consistent ability to achieve gross-section failure strains close to 0.005. That represents a considerable improvement over the state of the art.

  16. Structure, burial history, and petroleum potential of frontal thrust belt and adjacent foreland, southwest Montana.

    USGS Publications Warehouse

    Perry, W.J., Jr.; Wardlaw, B.R.; Bostick, N.H.; Maughan, E.K.

    1983-01-01

    The frontal thrust belt in the Lima area of SW Montana consists of blind (nonsurfacing) thrusts of the Lima thrust system beneath the Lima anticline and the Tendoy thrust sheet to the W. The Tendoy sheet involves Mississippian through Cretaceous rocks of the SW-plunging nose of the Mesozoic Blacktail-Snowcrest uplift that are thrust higher (NE) onto the uplift. The front of the Tendoy sheet W of Lima locally has been warped by later compressive deformation which also involved synorogenic conglomerates of the structurally underlying Beaverhead Formation. To the N, recent extension faulting locally has dropped the front of the Tendoy sheet beneath Quaternary gravels. Rocks of the exposed Tendoy sheet have never been deeply buried, based on vitrinite relectance of = or <0.6%, conodont CAI (color alteration index) values that are uniformly 1, and on supporting organic geochemical data from Paleozoic rocks from the Tendoy thrust sheet. Directly above and W of the Tendoy sheet lie formerly more deeply buried rocks of the Medicine Lodge thrust system. Their greater burial depth is indicated by higher conodont CAI values. W-dipping post-Paleocene extension faults truncate much of the rear part of the Tendoy sheet and also separate the Medicine Lodge sheet from thrust sheets of the Beaverhead Range still farther W. -from Authors

  17. Axial analysis of cones and adjacent retinal structures using AOSLO (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Papay, Joel A.; Johnston, Kirby D.; Sawides, Lucie; de Castro, Alberto; Burns, Stephen A.; Elsner, Ann E.

    2016-03-01

    We imaged the retina using the Indiana Adaptive Optics Scanning Laser Ophthalmoscope (AOSLO). Our system uses two deformable mirrors to provide en face, high-resolution images of retinal structures at a 28 Hz frame rate. The wavelength of the sensor light was 850 nm and the imaging wavelength was 820 nm at 50 and 120 °W respectively. The confocal pinhole was located in a position conjugate with the retina allowed us to segment one retina plane. Two different confocal apertures of 75 μm and 100 μm (1.5 and 2 times the Airy disk size) were used to provide different amounts of confocal or scattered light. The imaging area was 1.4 x 1.2 deg which corresponds roughly to 400 x 350 μm. Using the large stroke deformable mirror, which provides the focusing capability of the confocal system, we imaged the same location at different planes. We moved from superficial layers to the retinal pigment epithelium in 0.3 D increments. The range of adjustments included the subjectively best overall image, and focal planes anterior and posterior to this. We imaged 10 subjects at approximately 7.5 deg temporal from the fovea. A video of individual frames was taken, and the individual frames were dewarped, aligned, and averaged. We measured 10 bright and 10 dim cones for each subject at the 10 depths, with brightness groupings based subjectively on the most superficial location. The function for amount of light reflected differed for the two groups of cones. Reflectivity varied as a function of depth.

  18. Elements of a general theory of joints. 7. Mechanical structures of the relative motion of adjacent vertebrae.

    PubMed

    Nägerl, H; Kubein-Meesenburg, D; Fanghänel, J

    1992-02-01

    The mechanical structure of the relative motion of adjacent vertebrae is given by the interplay of the artt. zygapophysiales, the intervertebral disk and the ligaments, respectively. This structure will be described in the 3 main functional planes. Horizontal plane (parallel to the disk): The two artt. zygapophysiales structurally represent a force locked, kinematically contrained four-bar-chain (link quadrangle). It possesses but one degree of freedom. The intervertebral disk does not influence, therefore, the kinematic structure but the extent of the motion. Frontal-coronal plane: The four-bar-chain of the frontal plane seems to be inflexible. Lateral bending is only possible combined with a right or left handed axial rotation. Vertical-sagittal plane: The artt. zygapophysiales work as a single dimeric link chain. The momentary rotational center lies on the common normal of the two articular surfaces. Its position upon that is determined by the geometry of the applied force system according to the "reciprocal theorem of synarthroses". Solely one direction of translation is possible. A translation perpendicular to the intervertebral disk is impossible in the cervical and thoracic region. PMID:1605362

  19. Optimal design of viscous damper connectors for adjacent structures using genetic algorithm and Nelder-Mead algorithm

    NASA Astrophysics Data System (ADS)

    Bigdeli, Kasra; Hare, Warren; Tesfamariam, Solomon

    2012-04-01

    Passive dampers can be used to connect two adjacent structures in order to mitigate earthquakes induced pounding damages. Theoretical and experimental studies have confirmed efficiency and applicability of various connecting devices, such as viscous damper, MR damper, etc. However, few papers employed optimization methods to find the optimal mechanical properties of the dampers, and in most papers, dampers are assumed to be uniform. In this study, we optimized the optimal damping coefficients of viscous dampers considering a general case of non-uniform damping coefficients. Since the derivatives of objective function to damping coefficients are not known, to optimize damping coefficients, a heuristic search method, i.e. the genetic algorithm, is employed. Each structure is modeled as a multi degree of freedom dynamic system consisting of lumped-masses, linear springs and dampers. In order to examine dynamic behavior of the structures, simulations in frequency domain are carried out. A pseudo-excitation based on Kanai-Tajimi spectrum is used as ground acceleration. The optimization results show that relaxing the uniform dampers coefficient assumption generates significant improvement in coupling effectiveness. To investigate efficiency of genetic algorithm, solution quality and solution time of genetic algorithm are compared with those of Nelder-Mead algorithm.

  20. Comparison of phylogeographic structure and population history of two Phrynocephalus species in the Tarim Basin and adjacent areas.

    PubMed

    Zhang, Qian; Xia, Lin; He, Jingbo; Wu, Yonghua; Fu, Jinzhong; Yang, Qisen

    2010-12-01

    An aridification of the Tarim Basin and adjacent areas since middle Pleistocene has produced significant genetic structuring of the local fauna. We examined the phylogeographic patterns, population structure and history of Phrynocephalus axillaris and Phrynocephalus forsythii using a mitochondrial fragment ND4-tRNA(LEU). Phylogenetic hypotheses were constructed using maximum parsimony and Bayesian inference, and the divergence times of major lineages were estimated by BEAST. Population structure and history were inferred by nested clade analysis, neutrality tests, mismatch distribution, and isolation by distance analysis. The two species might have experienced different evolutionary history throughout their current distribution. For P. forsythii, a vicariant event, as a consequence of geological isolation and desert expansion, might have produced the significant divergence between the Tarim and the Yanqi populations. For P. axillaris, populations of the Yanqi, Turpan and Hami Basins might have been established through dispersal during demographic expansion. Climatic fluctuations caused alternate expansion and shrinkage of rivers and oases several times, which likely led to habitat fragmentation for both species. Interaction between vicariance, dispersal and habitat fragmentation produced the current distribution and genetic diversity. The observed difference between the two species may be due partially to their different reproductive modes (ovoviviparous vs. oviparous). PMID:20955804

  1. Quantitative Evaluation of the Substantially Variable Morphology and Function of the Left Atrial Appendage and Its Relation with Adjacent Structures

    PubMed Central

    Liu, Xiao-Wei; Fan, Qiong-Ying; Zhang, Xue-Jing; Liu, Guo-Chao; Yang, Hai-Qing; Feng, Ping-Yong; Wang, Yong; Song, Peng

    2015-01-01

    Objective To investigate quantitatively the morphology, anatomy and function of the left atrial appendage (LAA) and its relation with adjacent structures. Materials and Methods A total of 860 patients (533 men, 62.0%, age 55.9±10.4 year) who had cardiac multidetector computed tomography angiography from May to October 2012 were enrolled for analysis. Results Seven types and 6 subtypes of LAA morphology were found with Type 2 being the most prevalent. Type 5 was more significantly (P<0.05) present in women (8.0%) than in men (4.2%). LAA orifice was oval in 81.5%, triangular in 7.3%, semicircular in 4%, water drop-like in 3.2%, round in 2.4% and foot-like in 1.6%. The LAA orifice had a significantly greater (P<0.01) major axis in men (24.79±3.81) than in women (22.68±4.07). The LAA orifice long axis was significantly (P<0.05) positively correlated with the height, weight and surface area of the patient. The LAA morphology parameters displayed strong positive correlation with the left atrium volume, aortic cross area long axis or LSPV long axis but poor correlation with the height, weight, surface area and vertebral body height of the patients. Four types of LAA ridge were identified: AI, AII, B and C with the distribution of 17.6%, 69.9%, 5.9% and 6.6%, respectively. The LAA had a significantly (P<0.05) greater distance from its orifice to the mitral ring in women than in men. The LAA had two filling and two emptying processes with the greatest volume at 45% phase but the least volume at 5% phase. The LAA maximal, minimal and emptying volumes were all significantly (P<0.05) positively correlated with the body height, weight and surface area, whereas the LAA ejection fraction had an inverse correlation with the LAA minimal volume but no correlation with the maximal volume. Conclusion The LAA has substantially variable morphologies and relation with the adjacent structures, which may be helpful in guiding the LAA trans-catheter occlusion or catheter ablation

  2. Structural model of the lithosphere-asthenosphere system beneath the Qinghai-Tibet Plateau and its adjacent areas

    NASA Astrophysics Data System (ADS)

    Zhang, Xuemei; Teng, Jiwen; Sun, Ruomei; Romanelli, Fabio; Zhang, Zhongjie; Panza, Giuliano F.

    2014-11-01

    The deep structure of the lithosphere-asthenosphere system, as imaged from geophysical data, of the Qinghai-Tibet Plateau, the highest on the Earth, provides important clues in understanding its orogenic processes. Here we reconstruct the main features of the structure of the crust and upper mantle from surface wave tomography in the Qinghai-Tibet Plateau and its adjacent areas, in order to understand the modality of the convergence and collision process between the Indian and Eurasian plates. Based on Rayleigh waves dispersion theory, we collected long period and broad-band seismic data from the global and regional seismic networks surrounding the study area (20°N-50°N, 70°E-110°E). After applying instrument response calibration and filtering, group velocities of the fundamental mode of Rayleigh waves are measured using the frequency-time analysis (FTAN). Combining the published dispersion data, a 2-D surface-wave tomography method is applied to calculate the lateral variations of group velocity distribution at different periods, in the range from 8 s to 150 s. The Hedgehog non-linear inversion method is performed to obtain shear wave velocity (Vs) versus depth models of the crust and upper mantle for 181 cells, with size 2° × 2°. In order to identify the cellular representative models, we applied the local smoothness optimization method (LSO). Fairly detailed structural models of the lithosphere-asthenosphere system have been defined. The Vs models demonstrate the lateral variation of the thickness of the metasomatic lid between the south and north of the Bangong-Nujiang Suture (BNS) and the west and east of Tibet. The variation in thickness of the metasomatic lid may suggest that the leading edge of the subducting Indian slab reaches up to BNS.

  3. Integrated geophysical data processing and interpretation of crustal structure in Ethiopia with emphasis on the Ogaden Basin and adjacent areas

    NASA Astrophysics Data System (ADS)

    Tadesse, Ketsela

    The combined effects of magmatism and stretching due to asthenosphere upwelling modifies the crustal structure of the Earth as seen in the Ethiopian rift and adjacent areas. The Ethiopian rift provides unique opportunities to understand the nature of rifted crust and the intensity of its modification by magmatic processes. I used geological and geophysical data to conduct an integrated study in and around the Ethiopian rift including the northern Kenyan rift and the northern part of the Kenyan dome. New gravity, controlled source seismic, and teleseismic data from the EAGLE (Ethiopia-Afar Geoscientific Lithospheric Experiment) were used as additional constraints in my analysis of the crustal structure of Ethiopian rift and adjacent plateaus. Application of a residual gravity anomaly filtering technique using upward continuation revealed various crustal features within the Ethiopian rift and the flanking plateau regions. Short wavelength high amplitude positive anomalies coincide with the local volcanic complexes and calderas. In addition low gravity anomalies are associated with areas of thicker sediments within the rift valley. Axial and cross rift gravity profiles were modeled in 2.5 dimensions constrained with seismic refraction and geologic data. The axial model connects the Kenyan dome through Turkana rift and Main Ethiopian rift (MER) up to the Afar triple junction and provides a new integrated picture of lithospheric structure along the rift for over 1000 km. This model indicates a thin crust (26 km) underlying the Afar region. The crust gradually thickens towards the MER where it is about 35-40 km thick. Towards the south the crust thins and is only 22 km thick when it reaches the Turkana area. The southern section of the axial model indicates that the crust is about 35 km thick beneath the central Kenyan rift. All these thickness values are in agreement with the EAGLE and Kenya Rift International Seismic Project (KRISP) and earlier refraction results and

  4. A relationship between chemical structure and the critical temperature

    NASA Technical Reports Server (NTRS)

    Fedors, R. F.

    1982-01-01

    The present investigation is concerned with the effect of both molecular weight and chemical structure on the critical temperature. Using data from the comprehensive compilation of critical constants of Kudchadker et al. (1968), a simple relationship could be developed between the critical temperature and chemical structure. This relationship does not require experimental data such as the normal boiling point. It was found that the critical temperature (Tc) is given by an expression containing m and the sum of delta-i, where m is the total number of atoms in the molecule and delta-i is a number whose value is obtained from a table of additive atomic, group, and structural constants.

  5. Food structure is critical for optimal health.

    PubMed

    Wahlqvist, Mark L

    2016-03-16

    Much nutrition policy is nutrient-based, supported by extensive nutrient science and food nutrient composition tables and recommendations for dietary evaluation. There are no comparable instruments for food structure. This constitutes a policy and practice gap since food is valued for its textural properties and not simply its chemistry. The structurally-important 'dietary fibre' at first proved of greater interest for its chemistry than its physico-chemistry even to health scientists and workers. As food chemistry became evidently complex, especially for phytonutrients, food-based dietary guidelines became an imperative and were launched by FAO and WHO in Cyprus in 1995. Food-health relationships, after weaning, are best articulated in terms of the achievement of dietary diversity, predicated partly on how intact foods are or in what way they are prepared. Cooking itself has health-promoting characteristics. Even with identical chemistry, food structure makes a major difference to biological and health outcomes. With evidence that food structure contributes to the matrix that food provides for nutrient delivery, and also to gut microbiomic profile and integrity, concern has grown about overly-processed food and health outcomes. The definition and categorisation of 'ultra-processed foods' is now a work-in-progress. Future public health nutritional and clinical nutrition developments will take account of food structure. To these ends, food composition tables will need to provide information like particle size and viscosity. Dietary recommendations will need to take account of food structure, as is the case for Brazil whose first step is "Make natural or minimally processed foods the basis of your diet". PMID:26667120

  6. Critical parameters of superconducting materials and structures

    SciTech Connect

    Fluss, M.J.; Howell, R.H.; Sterne, P.A.; Dykes, J.W.; Mosley, W.D.; Chaiken, A.; Ralls, K.; Radousky, H.

    1995-02-01

    We report here the completion of a one year project to investigate the synthesis, electronic structure, defect structure, and physical transport properties of high temperature superconducting oxide materials. During the course of this project we produced some of the finest samples of single crystal detwinned YBa{sub 2}Cu{sub 3}O{sub 7}, and stoichiometrically perfect (Ba,K)BiO{sub 3}. We deduced the Fermi surface of YBa{sub 2}Cu{sub 3}O{sub 7}, (La,Sr){sub 2}CuO{sub 4}, and (Ba,K)BiO{sub 3} through the recording of the electron momentum density in these materials as measured by positron annihilation spectroscopy and angle resolved photoemission. We also performed extensive studies on Pr substituted (Y,Pr)Ba{sub 2}Cu{sub 3}O{sub 7} so as to further understand the origin of the electron pairing leading to superconductivity.

  7. Benthic polychaete diversity patterns and community structure in the Whittard Canyon system and adjacent slope (NE Atlantic)

    NASA Astrophysics Data System (ADS)

    Gunton, Laetitia M.; Neal, Lenka; Gooday, Andrew J.; Bett, Brian J.; Glover, Adrian G.

    2015-12-01

    We examined deep-sea macrofaunal polychaete species assemblage composition, diversity and turnover in the Whittard Canyon system (NE Atlantic) using replicate megacore samples from three of the canyon branches and one site on the continental slope to the west of the canyon, all at ~3500 m water depth. A total of 110 polychaete species were recorded. Paramphinome jeffreysii was the most abundant species (2326 ind. m-2) followed by Aurospio sp. B (646 ind. m-2), Opheliidae sp. A (393 ind. m-2), Prionospio sp. I (380 ind. m-2), and Ophelina abranchiata (227 ind. m-2). Species composition varied significantly across all sites. From west to east, the dominance of Paramphinome jeffreysii increased from 12.9% on the slope to 39.6% in the Eastern branch. Ordination of species composition revealed that the Central and Eastern branches were most similar, whereas the Western branch and slope sites were more distinct. High abundances of P. jeffreysii and Opheliidae sp. A characterised the Eastern branch of the canyon and may indicate an opportunistic response to a possible recent input of organic matter inside the canyon. Species richness and diversity indices were higher on the slope compared with inside the canyon, and the slope site had higher species evenness. Within the canyon, species diversity between branches was broadly similar. Despite depressed diversity within the canyon compared with the adjacent slope, the fact that 46 of the 99 polychaete species found in the Whittard Canyon were not present on the adjacent slope suggests that this feature may enhance the regional species pool. However, our sampling effort on the adjacent slope was insufficient to confirm this conclusion.

  8. Benthic meiofaunal composition and community structure in the Sethukuda mangrove area and adjacent open sea, East coast of India

    NASA Astrophysics Data System (ADS)

    Thilagavathi, Balasubramanaian; Das, Bandana; Saravanakumar, Ayyappan; Raja, Kuzhanthaivel

    2011-06-01

    The ecological aspects of meiofaunal communities in the Muthupettai mangrove forest, East coast of India, has not been investigated in the last two decades. Surface water temperature ranged from 23.5 °C to 31.8 °C. Salinity varied from 24 to 34 ppt, while water pH fluctuated from 7.4 to 8.3. Dissolved oxygen concentration ranged from 3.86 to 5.33 mg/l. Meiofauna analysis in this study identified a total of 106 species from the mangrove and adjacent open sea area of Sethukuda. Among these, 56 species of foraminiferans, 20 species of nematodes, 7 species of harpacticoid copepods, 4 species of ostrocodes, and 2 species of rotifers were identified. Furthermore, a single species was identified from the following groups: ciliophora, cnidaria, gnathostomulida, insecta, propulida, bryozoa and polychaete larvae. Meiofaunal density varied between 12029 to 23493 individuals 10 cm/m2. The diversity index ranged from 3.515 to 3.680, species richness index varied from 6.384 to 8.497, and evenness index varied from 0.839 to 0876 in the mangrove area and adjacent open sea.

  9. Food web structure of the coastal area adjacent to the Tagus estuary revealed by stable isotope analysis

    NASA Astrophysics Data System (ADS)

    Vinagre, C.; Máguas, C.; Cabral, H. N.; Costa, M. J.

    2012-01-01

    The identification of energy sources, pathways and trophic linkages among organisms is crucial for the understanding of food web dynamics. Stable isotopes were used to identify the trophic level of food web components and track the incorporation of organic matter of different origins in the coastal ecosystem adjacent to the Tagus estuary. It was shown that the river Tagus is a major source of organic carbon to this system. Also, the wide difference in δ 13C among the primary consumers allowed the identification of the pelagic and the benthic energy pathways. The maximum trophic level observed was 2.4 for Sepia officinalis. This value is indicative of a short food web. It was concluded that the diet of the upper trophic level species relies directly on the lower food web levels to a considerable extent, instead of relying mostly on intermediate trophic level species. Moreover, the δ 15N values of primary consumers were very close to that of particulate organic matter, probably due to poorly known processes occurring at the basis of the food web. This lowers the trophic length of the whole food web. Reliance on benthic affinity prey was high for all upper trophic level secondary consumers.

  10. Electromagnetic Structure of Few-Nucleon Systems: a Critical Review

    SciTech Connect

    R. Schiavilla

    2000-10-01

    Our current understanding of the structure of nuclei with up to A=8, including energy spectra, electromagnetic form factors, and capture reactions, is critically reviewed within the context of a realistic approach to nuclear dynamics based on two- and three-nucleon interactions and associated electromagnetic currents.

  11. The Impact of Adjacent-Dependencies and Staged-Input on the Learnability of Center-Embedded Hierarchical Structures

    ERIC Educational Resources Information Center

    Lai, Jun; Poletiek, Fenna H.

    2011-01-01

    A theoretical debate in artificial grammar learning (AGL) regards the learnability of hierarchical structures. Recent studies using an A[superscript n]B[superscript n] grammar draw conflicting conclusions ([Bahlmann and Friederici, 2006] and [De Vries et al., 2008]). We argue that 2 conditions crucially affect learning A[superscript…

  12. The Torsin-family AAA+ Protein OOC-5 Contains a Critical Disulfide Adjacent to Sensor-II That Couples Redox State to Nucleotide Binding

    PubMed Central

    Zhu, Li; Wrabl, James O.; Hayashi, Adam P.; Rose, Lesilee S.

    2008-01-01

    A subgroup of the AAA+ proteins that reside in the endoplasmic reticulum and the nuclear envelope including human torsinA, a protein mutated in hereditary dystonia, is called the torsin family of AAA+ proteins. A multiple-sequence alignment of this family with Hsp100 proteins of known structure reveals a conserved cysteine in the C-terminus of torsin proteins within the Sensor-II motif. A structural model predicts this cysteine to be a part of an intramolecular disulfide bond, suggesting that it may function as a redox sensor to regulate ATPase activity. In vitro experiments with OOC-5, a torsinA homolog from Caenorhabditis elegans, demonstrate that redox changes that reduce this disulfide bond affect the binding of ATP and ADP and cause an attendant local conformational change detected by limited proteolysis. Transgenic worms expressing an ooc-5 gene with cysteine-to-serine mutations that disrupt the disulfide bond have a very low embryo hatch rate compared with wild-type controls, indicating these two cysteines are essential for OOC-5 function. We propose that the Sensor-II in torsin family proteins is a redox-regulated sensor. This regulatory mechanism may be central to the function of OOC-5 and human torsinA. PMID:18550799

  13. The regional structural setting of the 2008 Wells earthquake and Town Creek Flat Basin: implications for the Wells earthquake fault and adjacent structures

    USGS Publications Warehouse

    Henry, Christopher S.; Colgan, Joseph P.

    2011-01-01

    The 2008 Wells earthquake occurred on a northeast-striking, southeast-dipping fault that is clearly delineated by the aftershock swarm to a depth of 10-12 km below sea level. However, Cenozoic rocks and structures around Wells primarily record east-west extension along north- to north-northeast-striking, west-dipping normal faults that formed during the middle Miocene. These faults are responsible for the strong eastward tilt of most basins and ranges in the area, including the Town Creek Flat basin (the location of the earthquake) and the adjacent Snake Mountains and western Windermere Hills. These older west-dipping faults are locally overprinted by a younger generation of east-dipping, high-angle normal faults that formed as early as the late Miocene and have remained active into the Quaternary. The most prominent of these east-dipping faults is the set of en-échelon, north-striking faults that bounds the east sides of the Ruby Mountains, East Humboldt Range, and Clover Hill (about 5 km southwest of Wells). The northeastern-most of these faults, the Clover Hill fault, projects northward along strike toward the Snake Mountains and the approximately located surface projection of the Wells earthquake fault as defined by aftershock locations. The Clover Hill fault also projects toward a previously unrecognized, east-facing Quaternary fault scarp and line of springs that appear to mark a significant east-dipping normal fault along the western edge of Town Creek Flat. Both western and eastern projections may be northern continuations of the Clover Hill fault. The Wells earthquake occurred along this east-dipping fault system. Two possible alternatives to rupture of a northern continuation of the Clover Hill fault are that the earthquake fault (1) is antithetic to an active west-dipping fault or (2) reactivated a Mesozoic thrust fault that dips east as a result of tilting by the west-dipping faults along the west side of the Snake Mountains. Both alternatives are

  14. Correlations and contrasts in structural history and style between an Archaean greenstone belt and adjacent gneiss belt, NE Minnesota

    NASA Technical Reports Server (NTRS)

    Bauer, R. L.; Hudleston, P. J.; Southwick, D. L.

    1986-01-01

    An analysis of the deformation along the boundary between the Vermilion Granitic Complex (VGC) and the Vermilion district indicates that the two terranes have seen a similar deformation history since the earliest stages of folding in the area. Despite this common history, variations in structural style occur between the two terranes, such as the relative development of D sub 1 fabrics and D sub 2 shear zones, and these can be attributed to differences in the crustal levels of the two terranes during the deformation. Similarly, the local development of F sub 3 folds in the VGC, but not in the Vermilion district, is interpreted to be a result of later-D sub 2 pluton emplacement which was not significant at the level of exposure of ther Vermilion district.

  15. Adjacent segment disease.

    PubMed

    Virk, Sohrab S; Niedermeier, Steven; Yu, Elizabeth; Khan, Safdar N

    2014-08-01

    EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Understand the forces that predispose adjacent cervical segments to degeneration. 2. Understand the challenges of radiographic evaluation in the diagnosis of cervical and lumbar adjacent segment disease. 3. Describe the changes in biomechanical forces applied to adjacent segments of lumbar vertebrae with fusion. 4. Know the risk factors for adjacent segment disease in spinal fusion. Adjacent segment disease (ASD) is a broad term encompassing many complications of spinal fusion, including listhesis, instability, herniated nucleus pulposus, stenosis, hypertrophic facet arthritis, scoliosis, and vertebral compression fracture. The area of the cervical spine where most fusions occur (C3-C7) is adjacent to a highly mobile upper cervical region, and this contributes to the biomechanical stress put on the adjacent cervical segments postfusion. Studies have shown that after fusion surgery, there is increased load on adjacent segments. Definitive treatment of ASD is a topic of continuing research, but in general, treatment choices are dictated by patient age and degree of debilitation. Investigators have also studied the risk factors associated with spinal fusion that may predispose certain patients to ASD postfusion, and these data are invaluable for properly counseling patients considering spinal fusion surgery. Biomechanical studies have confirmed the added stress on adjacent segments in the cervical and lumbar spine. The diagnosis of cervical ASD is complicated given the imprecise correlation of radiographic and clinical findings. Although radiological and clinical diagnoses do not always correlate, radiographs and clinical examination dictate how a patient with prolonged pain is treated. Options for both cervical and lumbar spine ASD include fusion and/or decompression. Current studies are encouraging regarding the adoption of arthroplasty in spinal surgery, but more long

  16. Crustal structure of Wrangellia and adjacent terranes inferred from geophysical studies along a transect through the northern Talkeetna Mountains

    USGS Publications Warehouse

    Glen, J.M.G.; Schmidt, J.; Pellerin, L.; McPhee, D.K.; O'Neill, J. M.

    2007-01-01

    Recent investigations of the Talkeetna Mountains in south-central Alaska were undertaken to study the region's framework geophysics and to reinterpret structures and crustal composition. Potential field (gravity and magnetic) and magnetotelluric (MT) data were collected along northwest-trending profiles as part of the U.S. Geological Survey's Talkeetna Mountains transect project. The Talkeetna Mountains transect area comprises eight 1:63,360 quadrangles (???9500 km2) in the Healy and Talkeetna Mountains 1?? ?? 3?? sheets that span four major lithostratigraphic terranes (Glen et al., this volume) including the Wrangellia and Peninsular terranes and two Mesozoic overlap assemblages inboard (northwest) of Wrangellia. These data were used here to develop 21/2-dimensional models for the three profiles. Modeling results reveal prominent gravity, magnetic, and MT gradients (???3.25 mGal/ km, ???100nT/km, ???300 ohm-m/km) corresponding to the Talkeetna Suture Zone-a first-order crustal discontinuity in the deep crust that juxtaposes rocks with strongly contrasting rock properties. This discontinuity corresponds with the suture between relatively dense magnetic crust of Wrangellia (likely of oceanic composition) and relatively less dense transitional crust underlying Jurassic to Cretaceous flysch basins developed between Wrangellia and North America. Some area of the oceanic crust beneath Wrangellia may also have been underplated by mafic material during early to mid-Tertiary volcanism. The prominent crustal break underlies the Fog Lakes basin approximately where theTalkeetna thrust faultwaspreviouslymappedas a surface feature. Potential fieldand MT models, however, indicate that the Talkeetna Suture Zone crustal break along the transect is a deep (2-8 km), steeply west-dipping structure-not a shallow east-dipping Alpine nappe-like thrust. Indeed, most of the crustal breaks in the area appear to be steep in the geophysical data, which is consistent with regional geologic

  17. Seismic structure beneath the Gulf of Aqaba and adjacent areas based on the tomographic inversion of regional earthquake data

    NASA Astrophysics Data System (ADS)

    El Khrepy, Sami; Koulakov, Ivan; Al-Arifi, Nassir; Petrunin, Alexey G.

    2016-06-01

    We present the first 3-D model of seismic P and S velocities in the crust and uppermost mantle beneath the Gulf of Aqaba and surrounding areas based on the results of passive travel time tomography. The tomographic inversion was performed based on travel time data from ˜ 9000 regional earthquakes provided by the Egyptian National Seismological Network (ENSN), and this was complemented with data from the International Seismological Centre (ISC). The resulting P and S velocity patterns were generally consistent with each other at all depths. Beneath the northern part of the Red Sea, we observed a strong high-velocity anomaly with abrupt limits that coincide with the coastal lines. This finding may indicate the oceanic nature of the crust in the Red Sea, and it does not support the concept of gradual stretching of the continental crust. According to our results, in the middle and lower crust, the seismic anomalies beneath the Gulf of Aqaba seem to delineate a sinistral shift (˜ 100 km) in the opposite flanks of the fault zone, which is consistent with other estimates of the left-lateral displacement in the southern part of the Dead Sea Transform fault. However, no displacement structures were visible in the uppermost lithospheric mantle.

  18. Seismic structure of the crust and uppermost mantle of north America and adjacent oceanic basins: A synthesis

    USGS Publications Warehouse

    Chulick, G.S.; Mooney, W.D.

    2002-01-01

    We present a new set of contour maps of the seismic structure of North America and the surrounding ocean basins. These maps include the crustal thickness, whole-crustal average P-wave and S-wave velocity, and seismic velocity of the uppermost mantle, that is, Pn and Sn. We found the following: (1) The average thickness of the crust under North America is 36.7 km (standard deviation [s.d.] ??8.4 km), which is 2.5 km thinner than the world average of 39.2 km (s.d. ?? 8.5) for continental crust; (2) Histograms of whole-crustal P- and S-wave velocities for the North American crust are bimodal, with the lower peak occurring for crust without a high-velocity (6.9-7.3 km/sec) lower crustal layer; (3) Regions with anomalously high average crustal P-wave velocities correlate with Precambrian and Paleozoic orogens; low average crustal velocities are correlated with modern extensional regimes; (4) The average Pn velocity beneath North America is 8.03 km/sec (s.d. ?? 0.19 km/sec); (5) the well-known thin crust beneath the western United States extends into northwest Canada; (6) the average P-wave velocity of layer 3 of oceanic crust is 6.61 km/ sec (s.d. ?? 0.47 km/sec). However, the average crustal P-wave velocity under the eastern Pacific seafloor is higher than the western Atlantic seafloor due to the thicker sediment layer on the older Atlantic seafloor.

  19. Mapping of lithologic and structural units using multispectral imagery. [Afar-Triangle/Ethiopia and adjacent areas (Ethiopian Plateau, Somali Plateau, and parts of Yemen and Saudi Arabia)

    NASA Technical Reports Server (NTRS)

    Kronberg, P. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. ERTS-1 MSS imagery covering the Afar-Triangle/Ethiopia and adjacent regions (Ethiopian Plateau, Somali Plateau, and parts of Yemen and Saudi Arabi) was applied to the mapping of lithologic and structural units of the test area at a scale 1:1,000,000. Results of the geological evaluation of the ERTS-1 imagery of the Afar have proven the usefullness of this type of satellite data for regional geological mapping. Evaluation of the ERTS images also resulted in new aspects of the structural setting and tectonic development of the Afar-Triangle, where three large rift systems, the oceanic rifts of the Red Sea and Gulf of Aden and the continental East African rift system, seem to meet each other. Surface structures mapped by ERTS do not indicate that the oceanic rift of the Gulf of Aden (Sheba Ridge) continues into the area of continental crust west of the Gulf of Tadjura. ERTS data show that the Wonji fault belt of the African rift system does not enter or cut through the central Afar. The Aysha-Horst is not a Horst but an autochthonous spur of the Somali Plateau.

  20. Fish diversity in the Río de la Plata and adjacent waters: an overview of environmental influences on its spatial and temporal structure.

    PubMed

    Jaureguizar, A J; Solari, A; Cortés, F; Milessi, A C; Militelli, M I; Camiolo, M D; Luz Clara, M; García, M

    2016-07-01

    The fish diversity and the main environmental factors affecting the spatial distribution of species, life history stages and community structure in the Río de la Plata (RdP) and adjacent waters are reviewed and analysed, with emphasis on the functional guild classification. The functional guild classification indicated that most species in the RdP were marine stragglers, zoobenthivores and oviparous species, although the biomass was dominated by estuarine species. Salinity had a stronger influence than temperature on the spatial pattern for all life stages, shallower and fresher waters are the preferred habitats of neonates and juveniles. During the breeding season (spring-summer), adults showed an intrusion into the inner part of RdP or to its adjacent nearshore waters from the offshore waters for spawning or mating, respectively. Variations in river discharge and wind patterns greatly affected the spatial extent of estuarine water, which ultimately influenced the domain of the main life-history stages (juveniles or adults) for both marine and estuarine fishes, as well as species and fish assemblage composition. The strong environmental gradient restricts some species and life-history stages to a particular section and defines three main fish assemblage areas. The composition of the fish assemblage is indicative of the recruitment of freshwater and marine species to the estuary in opposite ways, determined by the vertical stratification. Seasonal changes in the species composition were related to migration as a result of salinity and temperature variations and reproductive migrations to spawning and mating areas. This overview reveals that the RdP is under environmental variations that are likely to produce modifications to fish distribution and abundance that affect its fisheries. This context plus fish stock declines and changes in exploitation patterns could amplify the magnitude of the variations in the fisheries resources availability and affect the

  1. Generic criticality of community structure in random graphs

    NASA Astrophysics Data System (ADS)

    Lipowski, Adam; Lipowska, Dorota

    2014-09-01

    We examine a community structure in random graphs of size n and link probability p /n determined with the Newman greedy optimization of modularity. Calculations show that for p <1 communities are nearly identical with clusters. For p =1 the average sizes of a community sav and of the giant community sg show a power-law increase sav˜nα' and sg˜nα. From numerical results we estimate α'≈0.26(1) and α ≈0.50(1) and using the probability distribution of sizes of communities we suggest that α'=α/2 should hold. For p >1 the community structure remains critical: (i) sav and sg have a power-law increase with α'≈α<1 and (ii) the probability distribution of sizes of communities is very broad and nearly flat for all sizes up to sg. For large p the modularity Q decays as Q˜p-0.55, which is intermediate between some previous estimations. To check the validity of the results, we also determine the community structure using another method, namely, a nongreedy optimization of modularity. Tests with some benchmark networks show that the method outperforms the greedy version. For random graphs, however, the characteristics of the community structure determined using both greedy and nongreedy optimizations are, within small statistical fluctuations, the same.

  2. Fault-block structure and state of stress in the Earth's crust of the Gusinoozersky Basin and the adjacent territory, western Transbaikal region

    NASA Astrophysics Data System (ADS)

    Lunina, O. V.; Gladkov, A. S.

    2009-01-01

    The geological structure and tectonophysics of the Gusinoozersky Basin—a tectonotype of Mesozoic depressions in the western Transbaikal region—is discussed. New maps of the fault-block structure and state of stress in the Earth’s crust of the studied territory are presented. It is established that the Gusinoozersky Basin was formed in a transtensional regime with the leading role of extension oriented in the NW-SE direction. The transtensional conditions were caused by paths of regional tension stresses oriented obliquely to the axial line of the basin, which created a relatively small right-lateral strike-slip component of separation (in comparison with normal faulting) along the NE-trending master tectonic lines. The widespread shear stress tensors of the second order with respect to extension are related to inhomogeneities in the Earth’s crust, including those that are arising during displacement of blocks along normal faults. Folding at the basin-range boundary was brought about by gravity effects of normal faulting. The faults and blocks in the Gusinoozersky Basin remained active in the Neogene and Quaternary; however, it is suggested that their reactivation was a response to tectonic processes that occurred in the adjacent Baikal Rift Zone rather than to the effect of a local mantle source.

  3. An unusual triangle zone in the external northern Alpine foreland (Switzerland): Structural inheritance, kinematics and implications for the development of the adjacent Jura fold-and-thrust belt

    NASA Astrophysics Data System (ADS)

    Malz, Alexander; Madritsch, Herfried; Meier, Beat; Kley, Jonas

    2016-02-01

    Triangle zones represent typical structural elements of thin-skinned foreland fold-and-thrust belts. Here, we report the results of an in-depth structural analysis of a rather unusual triangle zone at the front of the easternmost Jura fold-and-thrust belt in the otherwise only very mildly deformed Alpine foreland of Northern Switzerland. The investigation is based on the interpretation of recently reprocessed and depth-migrated 2D reflection seismic sections. Classical bed-length and area cross-section balancing methods were used to validate the interpretation and unravel the tectonic evolution of the triangle zone. According to our interpretation the analyzed triangle zone formed along the Baden-Irchel-Herdern-Lineament (BIH-Lineament), a regional Paleozoic normal fault that shows evidence of Cenozoic reactivation. The triangle zone is composed of one major foreland-directed thrust rooting in Triassic evaporites and a back-thrust splaying from it in the Middle Jurassic Opalinus Clay, pointing to the importance of secondary detachments. Steeply dipping secondary reverse faults next to the triangle zone suggest reactivation of pre-existing normal faults. The formation of the thrust triangle is considered to relate to thin-skinned foreland deformation in Late Miocene time. Strain estimations of the thrust triangle along-strike show a laterally very uniform amount of shortening, which is in contrast to the southward adjacent Jura fold-and-thrust belt. We interpret this constant shortening to represent the maximum contractional strain attainable by the specific geometry of the BIH triangle zone. At this point, the complex structure became mechanically ineffective and further shortening led to the formation of new contractional structures in its hinterland. This kinematic hypothesis suggests an early-stage formation of the BIH triangle zone followed by back stepping of the deformation front. As such, it challenges the classical view of a purely forward-breaking sequence

  4. Critical thresholds in species` responses to landscape structure

    SciTech Connect

    With, K.A.; Crist, T.O.

    1995-12-01

    Critical thresholds are transition ranges across which small changes in spatial pattern produce abrupt shifts in ecological responses. Habitat fragmentation provides a familiar example of a critical threshold. As the landscape becomes dissected into smaller parcels of habitat. landscape connectivity-the functional linkage among habitat patches - may suddenly become disrupted, which may have important consequences for the distribution and persistence of populations. Landscape connectivity depends not only on the abundance and spatial patterning of habitat. but also on the habitat specificity and dispersal abilities of species. Habitat specialists with limited dispersal capabilities presumably have a much lower threshold to habitat fragmentation than highly vagile species, which may perceive the landscape as functionally connected across a greater range of fragmentation severity. To determine where threshold effects in species, responses to landscape structure are likely to occur, a simulation model modified from percolation theory was developed. Our simulations predicted the distributional patterns of populations in different landscape mosaics, which we tested empirically using two grasshopper species (Orthoptera: Acrididae) that occur in the shortgrass prairie of north-central Colorado. The distribution of these two species in this grassland mosaic matched the predictions from our simulations. By providing quantitative predictions of threshold effects, this modelling approach may prove useful in the formulation of conservation strategies and assessment of land-use changes on species` distributional patterns and persistence.

  5. Lithospheric structure beneath the central and western North China Craton and the adjacent Qilian orogenic belt from Rayleigh wave dispersion analysis

    NASA Astrophysics Data System (ADS)

    Wei, Zigen; Chen, Ling; Jiang, Mingming; Ling, Yuan

    2015-04-01

    We used surface wave tomography to image the lithospheric S-wave velocity structure along a linear seismic array across the central and western North China Craton (NCC) and the adjacent Qilian orogenic belt (QB). Using waveform data from 8 earthquakes collected at 60 broadband stations, Rayleigh wave phase velocities were measured at periods of 20-120 s and subsequently inverted for reliable S-wave velocities from 60 to 200 km depth. Distinct lithospheric structures and marked lateral variations were revealed beneath the study region, correlating well with regional geological and tectonic features. The average S-wave velocity from 60 to 200 km depth beneath the array is ~ 4.45 km/s, ~ 1% lower than that in model AK135. High velocities of > 4.45 km/s are most pronounced beneath the stable Ordos Block (western NCC). However, the depth to which the observed high velocity body extends varies significantly laterally. It is deepest (~ 200 km) under eastern Ordos, and becomes shallower on both sides along the array. The maximum depth of the high velocity body gradually shallows westward and reaches ~ 110 km near the western edge of Ordos. This depth variation suggests a coexistence of both preserved and modified lithosphere in Ordos. The depth of high velocities decreases rapidly eastward by > 80 km over a lateral distance of < 200 km across the North-south Gravity Lineament (NSGL) in central NCC, supporting the speculation that the NSGL represents a major continental-lithospheric boundary. A stratified lithospheric mantle was revealed beneath QB, the ~ 2% low velocity anomaly above 100 km depth may be attributed partially to a higher temperature here. Our study revealed rapid lithospheric structural variations beneath NSGL and the boundary zone between Ordos and QB, probably reflecting long-lived, inherited weaknesses in lithosphere that may have been enhanced by episodic tectonic reactivations during the evolution of NCC.

  6. Technique for sparing previously irradiated critical normal structures in salvage proton craniospinal irradiation

    PubMed Central

    2013-01-01

    Background Cranial reirradiation is clinically appropriate in some cases but cumulative radiation dose to critical normal structures remains a practical concern. The authors developed a simple technique in 3D conformal proton craniospinal irradiation (CSI) to block organs at risk (OAR) while minimizing underdosing of adjacent target brain tissue. Methods Two clinical cases illustrate the use of proton therapy to provide salvage CSI when a previously irradiated OAR required sparing from additional radiation dose. The prior radiation plan was coregistered to the treatment planning CT to create a planning organ at risk volume (PRV) around the OAR. Right and left lateral cranial whole brain proton apertures were created with a small block over the PRV. Then right and left lateral “inverse apertures” were generated, creating an aperture opening in the shape of the area previously blocked and blocking the area previously open. The inverse aperture opening was made one millimeter smaller than the original block to minimize the risk of dose overlap. The inverse apertures were used to irradiate the target volume lateral to the PRV, selecting a proton beam range to abut the 50% isodose line against either lateral edge of the PRV. Together, the 4 cranial proton fields created a region of complete dose avoidance around the OAR. Comparative photon treatment plans were generated with opposed lateral X-ray fields with custom blocks and coplanar intensity modulated radiation therapy optimized to avoid the PRV. Cumulative dose volume histograms were evaluated. Results Treatment plans were developed and successfully implemented to provide sparing of previously irradiated critical normal structures while treating target brain lateral to these structures. The absence of dose overlapping during irradiation through the inverse apertures was confirmed by film. Compared to the lateral X-ray and IMRT treatment plans, the proton CSI technique improved coverage of target brain tissue

  7. The structure of the CARD8 caspase-recruitment domain suggests its association with the FIIND domain and procaspases through adjacent surfaces.

    PubMed

    Jin, Tengchuan; Huang, Mo; Smith, Patrick; Jiang, Jiansheng; Xiao, T Sam

    2013-05-01

    CARD8 plays crucial roles in regulating apoptotic and inflammatory signaling pathways through the association of its caspase-recruitment domain (CARD) with those of procaspase-9 and procaspase-1. The CARD8 CARD has also been predicted to form an intramolecular complex with its FIIND domain. Here, the first crystal structure of the CARD8 CARD is reported; it adopts a six-helix bundle fold with a unique conformation of the α6 helix that is described here for the first time. The surface of the CARD8 CARD displays a prominent acidic patch at its α2, α3 and α5 helices that may interact with the procaspase-9 CARD, whereas an adjacent charged surface at its α3 and α4 helices may associate with the CARD8 FIIND domain without interfering with the CARD-CARD interaction. This suggests that the function of CARD8 may be regulated by both intramolecular and intermolecular interactions involving electrostatic attractions. PMID:23695559

  8. Crustal and upper-mantle Seismic Tomography beneath the Helan-Liupan-Ordos's western margin structural belt and its adjacent region in central China

    NASA Astrophysics Data System (ADS)

    Cheng, S.; Cheng, B.; Zhang, G.; Zhao, D.

    2013-12-01

    Abstract We determined high-resolution 3-D P-wave velocity and anisotropic structures under the Helan-Liupan-Ordos's western margin (H-L-O) structural belt and its adjacent region using 13,506 P-wave high-quality arrival times from 2,666 regional earthquakes recorded by 87 seismic stations distributed in Northwestern China during 1980 to 2008. The results indicate that the prominent low-Vp anomalies widely exist in the lower crust beneath the study region and extend to the uppermost mantle in local area, which suggest that the lower crust contains relative high-temperature materials and/or fluids. The major fault zones especial the large boundary faults are distributed in the edge portion of the low-Vp anomalies or a transitional zone between the low- and high-Vp anomalies in the upper crust, and the obvious low-Vp anomalies are revealed in the lower crust even uppermost mantle under most of the faults. Most of the large historical earthquakes are located in the boundary zones where P-wave velocity changes drastically in a short distance. The prominent low-Vp zones are visible in the lower crust even uppermost mantle beneath the large historical earthquakes and most of the regional earthquakes. The anisotropic patterns in the upper crust is good consistent with the surface structures. In the lower crust and uppermost mantle, the predominant fast velocity direction has the NNE-SSW under the Yinchuan Graben and NWW-SEE or NW-SE beneath the Corridor transitional zone, Qilian Orogenic Belt and Western Qinling Orogenic Belt with about NE-SW in local region such as eastern Qilian Orogenic Belt, respectively, being caused by the LPO of lower crustal minerals which may be result from the ductile flow of the lower crust with varied flow directions. Another velocity feature is being zonation with low- and high-velocity S-N strike and segments along S-N within the Crust. The present results shed new light on the structural heterogeneities and seismic anisotropy in the crust

  9. Ectomycorrhizal Community Structure and Soil Characteristics of Mature Lodgepole Pine (Pinus Contorta) and Adjacent Stands of Old Growth Mixed Conifer in Yellowstone National Park, Wyoming USA

    NASA Technical Reports Server (NTRS)

    Douglas, Robert B.; Parker, V. Thomas; Cullings, Kenneth W.; Sun, Sidney (Technical Monitor)

    2003-01-01

    Forest development patterns following disturbance are known to influence the physical and chemical attributes of soils at different points in time. Changes in soil resources are thought to have a corresponding effect on ectomycorrhizal (ECM) community structure. We used molecular methods to compare below-ground ECM species richness, composition, and abundance between adjacent stands of homogenous lodgepole pine and old growth mixed conifer in Yellowstone National Park (YNP). In each stand-type we collected soil cores to both identify mycorrhizae and assess soil chemistry. Although no statistical difference was observed in the mean number of ECM root tips per core between stand types, the total number of species identified (85 versus 35) and the mean number of species per core (8.8 +/- 0.6 versus 2.5 +/- 0.3) were significantly higher in lodgepole pine. Differences between the actual and estimated species richness levels indicated that these forest types support a high number of ECM species and that undersampling was severe. Species compositions were widely disparate between stands where only four species were shared out of a total of 116. Soil analysis also revealed that mixed conifer was significantly lower in pH, but higher in organic matter, potassium, phosphorus, and ammonium when compared to lodgepole pine stands. Species richness per core was correlated with these chemical data, however, analysis of covariance indicated that stand type was the only statistically significant factor in the observed difference in species richness. Our data suggest that ECM fungal richness increases as homogenous lodgepole pine stands grow and mature, but declines after Engelmann spruce and subalpine fir colonize. Despite difficulties linking species composition with soil chemistry, there are a variety of physical and chemical factors that could be influencing ECM community structure. Future field experiments are necessary to test some of the mechanisms potentially operating

  10. An Approach by Structural Metaphor to the Teaching of Modern Literary Criticism.

    ERIC Educational Resources Information Center

    Adair, William Leith

    Modern literary criticism may be classified into four categories to provide a format for instruction which both reduces modern criticism to its essential interests and provides a critical vocabulary which is a mediating vocabulary between modern criticism and literature. These categories are summed up in structural metaphors: Symbolic Form,…

  11. Critical Structure for Telescopic Movement of Honey bee (Insecta: Apidae) Abdomen: Folded Intersegmental Membrane

    PubMed Central

    Zhao, Jieliang; Yan, Shaoze; Wu, Jianing

    2016-01-01

    The folded intersegmental membrane is a structure that interconnects two adjacent abdominal segments; this structure is distributed in the segments of the honey bee abdomen. The morphology of the folded intersegmental membrane has already been documented. However, the ultrastructure of the intersegmental membrane and its assistive role in the telescopic movements of the honey bee abdomen are poorly understood. To explore the morphology and ultrastructure of the folded intersegmental membrane in the honey bee abdomen, frozen sections were analyzed under a scanning electron microscope. The intersegmental membrane between two adjacent terga has a Z–S configuration that greatly influences the daily physical activities of the honey bee abdomen. The dorsal intersegmental membrane is 2 times thicker than the ventral one, leading to asymmetric abdominal motion. Honey bee abdominal movements were recorded using a high-speed camera and through phase-contrast computed tomography. These movements conformed to the structural features of the folded intersegmental membrane. PMID:27456912

  12. Critical Structure for Telescopic Movement of Honey bee (Insecta: Apidae) Abdomen: Folded Intersegmental Membrane.

    PubMed

    Zhao, Jieliang; Yan, Shaoze; Wu, Jianing

    2016-01-01

    The folded intersegmental membrane is a structure that interconnects two adjacent abdominal segments; this structure is distributed in the segments of the honey bee abdomen. The morphology of the folded intersegmental membrane has already been documented. However, the ultrastructure of the intersegmental membrane and its assistive role in the telescopic movements of the honey bee abdomen are poorly understood. To explore the morphology and ultrastructure of the folded intersegmental membrane in the honey bee abdomen, frozen sections were analyzed under a scanning electron microscope. The intersegmental membrane between two adjacent terga has a Z-S configuration that greatly influences the daily physical activities of the honey bee abdomen. The dorsal intersegmental membrane is 2 times thicker than the ventral one, leading to asymmetric abdominal motion. Honey bee abdominal movements were recorded using a high-speed camera and through phase-contrast computed tomography. These movements conformed to the structural features of the folded intersegmental membrane. PMID:27456912

  13. Unraveling Structural Infrasound: understanding the science for persistent remote monitoring of critical infrastructure (Invited)

    NASA Astrophysics Data System (ADS)

    McKenna, S. M.; Diaz-Alvarez, H.; McComas, S.; Costley, D.; Whitlow, R. D.; Jordan, A. M.; Taylor, O.

    2013-12-01

    structural impact assessment. The Interstate-20 Mississippi River Bridge in Vicksburg, MS is a 7 span, cantilever bridge. On March 23, 2011, a barge moving downstream struck a pier of the bridge. Infrasound stations located approximately 4.5 km away detected the impact. Coincidentally, ERDC had instrumented the bridge with strain gages and accelerometers as part of a structural health monitoring project. Finite Element (FE) models were developed to investigate the structural behavior of the bridge due to the impact, with experimental data and FE models validating source mechanism of the infrasound from the bridge. Health assessment of large dams, whether for flood control or power generation, is critical for both civilian and military applications. Ambient excitations can induce measurable responses in the dam, adjacent foundation and in the reservoir, some of which are in the infrasound passband. The Portugues Dam outside of Ponce, Puerto Rico, is being investigated. Currently in the final stages of construction, infrasound array data collections over all four seasons before and after the opening of the dam will provide a seasonally variable database, begun in July 2013. Impulsive excitation using an instrumented Cold Gas thruster (CGT) instrumented with a dynamic force sensor induces transient frequency responses in the dam, reservoir, and along the dam-foundation interface below 20 Hz, to allow for controlled source validation.

  14. Critical ratios for structural analysis of triacylglycerols using mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent developments have finally allowed fragment behaviors using APCI-MS to be elucidated after twenty years of literature reports. Critical Ratios have been defined that correspond to various aspects of triacylglycerol (TAG) analysis, from overall degree of unsaturation to localization of fatty ac...

  15. Probabilistic structural analysis methods for critical SSME propulsion components

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1986-01-01

    The development of a three-dimensional inelastic analysis methodology for the Space Shuttle main engine (SSME) structural components is described. The methodology is composed of: (1) composite load spectra, (2) probabilistic structural analysis methods, (3) the probabilistic finite element theory, and (4) probabilistic structural analysis. The progress in the development of generic probabilistic models for various individual loads which consist of a steady state load, a periodic load, a random load, and a spike, is discussed. The capabilities of the Numerical Evaluation of Stochastic Structures Under Stress finite element code designed for probabilistic structural analysis of the SSME are examined. Variation principles for formulation probabilistic finite elements and a structural analysis for evaluating the geometric and material properties tolerances on the structural response of turbopump blades are being designed.

  16. Timing the structural events in the Palaeoproterozoic Bolé-Nangodi belt terrane and adjacent Maluwe basin, West African craton, in central-west Ghana

    NASA Astrophysics Data System (ADS)

    de Kock, G. S.; Théveniaut, H.; Botha, P. M. W.; Gyapong, W.

    2012-04-01

    The Maluwe basin, north-adjacent to the Sunyani basin, is the northernmost of the northeast-trending Eburnean volcaniclastic depositories in Ghana. These basins are separated from one another by remnants of Eoeburnean crust, all formed during the evolution of an arc-backarc basins complex in a Palaeoproterozoic intraoceanic environment. The Bolé-Nangodi belt terrane to the northwest, of mostly Eoeburnean crust is fault bounded with the Maluwe basin along the northeast-trending Bolé-Navrongo fault zone. The stratigraphic sequence, which was the key to unravelling the structural evolution of the study area, was established by means of field observations aided by precision SHRIMP geochronology. The quartzitic, pelitic, quartzofeldspathic and granitic gneisses of the Eoeburnean crust (>2150 Ma) experienced complex metamorphic mineral growth and migmatitization, mostly under static crustal conditions and were subjected to several deformation episodes. The foliated mafic and metasedimentary enclaves within the Ifanteyire granite establish deformation to have taken place prior to ˜2195 Ma, while the tectonically emplaced Kuri amphibolites within the 2187-Ma gneissic Gondo granite indicate a stage of rifting followed by collision. Deformation of granite dykes in the Gondo granites at ˜2150 Ma concluded the development of the Eoeburnean orogenic cycle (DEE). The Sawla Suite, contemporaneous with the deposition of the Maluwe Group, intruded the tectonic exhumed Bolé-Nangodi terrane during extension between ˜2137 and 2125 Ma. The rifting separated the Abulembire fragment from the Bolé-Nangodi terrane. During subsequent northwestward subduction of young back-arc basin oceanic crust the volcaniclastic strata of the Maluwe Group and Sawla granitoids were deformed (DE1) under chlorite/sericite greenschist-grade conditions. The NE-trending folds had subhorizontal axes and subvertical axial planes. Simultaneous to the DE1 orogenesis the molasses of the Banda Group was

  17. Nondestructive evaluation of critical composite material structural elements

    NASA Astrophysics Data System (ADS)

    Duke, John C., Jr.; Lesko, John J.; Weyers, R.

    1996-11-01

    A small span bridge that has suffered corrosive deterioration of a number of the steel structural members is in the process of being rehabilitated with glass and carbon fiber reinforced, pultruded polymer structural beams. As part of a comprehensive research program to develop methods for modeling long term durability of the composite material, nondestructive evaluation if being used to provide a preliminary assessment of the initial condition of the beams as well as to monitor the deterioration of the beams during service.

  18. Critical requirements for the design of large space structures

    NASA Technical Reports Server (NTRS)

    Hedgepeth, J. M.

    1981-01-01

    The requirements for the design of a large space structure which will be deployed, erected, assembled or fabricated in space are delineated in terms of operational loads, stiffness requirements, structure-control interaction, deformations, precision requirements and member slenderness. Design examples for a truss antenna reflector, interorbit propulsion loads and free-flying solar reflectors are given. It is concluded that the demand for dimensional accuracy and stability form the primary requirements.

  19. Structural health monitoring of materials by high critical temperature SQUID

    NASA Astrophysics Data System (ADS)

    Valentino, M.; Ruosi, A.; Peluso, G.; Pepe, G. P.

    2002-08-01

    Nowadays, tailoring the material properties is essential for advanced product design in engineering systems. The need to provide key information about micro- and macro-structural behaviour of materials, without destructively sectioning the sample, has spurred the development of nondestructive evaluation methodologies. These techniques are required during material production, quality testing of components during manufacturing, and in-service inspection of structural integrity. To ensure the highest possible operational safety along with an economic efficiency, it is necessary to carry out inspections with a high sensitivity and a proven reliability. Due to its unparalleled magnetic field sensitivity over a wide frequency range and large dynamic range, SQUID-based nondestructive evaluation has unique advantages for materials and structures characterization. We will present an overview of eddy-current nondestructive analysis utilizing high Tc SQUIDs with an emphasis on examples relevant to the aeronautical industry. These include the detection of deep-lying defects in multi-layer structures of Al-Ti alloys and damage of extremely lightweight graphite/epoxy composites. Both of these can be successfully treated by this approach where conventional electromagnetic probes often fail. In addition some results based on the volume integral formulation, successfully developed to simulate the response of the system to different type of flaws in Al-alloy planar structures and to solve the inverse electromagnetic problem, will be shown.

  20. Critical fluctuations in the domain structure of lipid membranes

    NASA Astrophysics Data System (ADS)

    Halstenberg, S.; Schrader, W.; Das, P.; Bhattacharjee, J. K.; Kaatze, U.

    2003-03-01

    Between 100 kHz and 2 GHz ultrasonic attenuation spectra of two aqueous solutions of vesicles from 1,2-dimyristoyl-L-3-phosphatidylcholine have been measured at 13 temperatures around the main phase transition temperature of the membranes. The spectra are analyzed in terms of an asymptotic high frequency background contribution and three relaxation terms. Two of these terms can be represented by a discrete relaxation time, respectively, the other one extends over a significantly broader frequency range than a Debye-type relaxation term. It was found to nicely follow the predictions of the Bhattacharjee-Ferrell model of three-dimensional critical fluctuations. This finding has been additionally verified by measurements of the scaling function and by an analysis of the relaxation rate of order parameter fluctuations following from the fit of the experimental scaling function data to the theoretical form. Theoretical arguments are presented to indicate why the three-dimensional theory applies so well to the quasi-two-dimensional membrane system.

  1. Structured Case Analysis: Developing Critical Thinking Skills in a Marketing Case Course

    ERIC Educational Resources Information Center

    Klebba, Joanne M.; Hamilton, Janet G.

    2007-01-01

    Structured case analysis is a hybrid pedagogy that flexibly combines diverse instructional methods with comprehensive case analysis as a mechanism to develop critical thinking skills. An incremental learning framework is proposed that allows instructors to develop and monitor content-specific theory and the corresponding critical thinking skills.…

  2. A critical review of social and structural conditions that influence HIV risk among Mexican deportees

    PubMed Central

    Pinedo, Miguel; Burgos, José Luis; Ojeda, Victoria D.

    2014-01-01

    Mexican migrants who are deported from the US may be at elevated risk for HIV infection. Deportations of Mexican migrants by the US have reached record numbers. We critically reviewed existing literature to assess how social and structural conditions in post-deportation settings can influence Mexican deported migrants' HIV risk. We also identify critical research gaps and make research recommendations. PMID:24583278

  3. Extended Aging Theories for Predictions of Safe Operational Life of Critical Airborne Structural Components

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Chen, Tony

    2006-01-01

    The previously developed Ko closed-form aging theory has been reformulated into a more compact mathematical form for easier application. A new equivalent loading theory and empirical loading theories have also been developed and incorporated into the revised Ko aging theory for the prediction of a safe operational life of airborne failure-critical structural components. The new set of aging and loading theories were applied to predict the safe number of flights for the B-52B aircraft to carry a launch vehicle, the structural life of critical components consumed by load excursion to proof load value, and the ground-sitting life of B-52B pylon failure-critical structural components. A special life prediction method was developed for the preflight predictions of operational life of failure-critical structural components of the B-52H pylon system, for which no flight data are available.

  4. Efficient identification of critical stresses in structures subject to dynamic loads

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Watson, L. T.; Grandhi, R. V.

    1986-01-01

    Optimum structural design problems generally employ constraints which are parametric in terms of space and time variables. A parametric constraint may be replaced by equivalent critical point constraints at its local minima for optimization applications. In complex structures, accurate identification of such critical points is computationally expensive due to the cost of finite element analyses. Three techniques are described for efficiently and accurately identifying critical points for space- and time-dependent parametric constraints. An adaptive search technique and a spline interpolation technique are developed for exactly known response. A least squares spline approximation is suggested for noisy behavior. A helicopter tail-boom structure subjected to transient loading is used as an example to demonstrate the techniques described. All three techniques are shown to be computationally efficient for critical point identification and the least squares approximation also removes noise from the data. The case of multiple constraints per element is shown to be particularly suited to the use of spline techniques.

  5. Development of a structural health monitoring system for the life assessment of critical transportation infrastructure.

    SciTech Connect

    Roach, Dennis Patrick; Jauregui, David Villegas; Daumueller, Andrew Nicholas

    2012-02-01

    Recent structural failures such as the I-35W Mississippi River Bridge in Minnesota have underscored the urgent need for improved methods and procedures for evaluating our aging transportation infrastructure. This research seeks to develop a basis for a Structural Health Monitoring (SHM) system to provide quantitative information related to the structural integrity of metallic structures to make appropriate management decisions and ensuring public safety. This research employs advanced structural analysis and nondestructive testing (NDT) methods for an accurate fatigue analysis. Metal railroad bridges in New Mexico will be the focus since many of these structures are over 100 years old and classified as fracture-critical. The term fracture-critical indicates that failure of a single component may result in complete collapse of the structure such as the one experienced by the I-35W Bridge. Failure may originate from sources such as loss of section due to corrosion or cracking caused by fatigue loading. Because standard inspection practice is primarily visual, these types of defects can go undetected due to oversight, lack of access to critical areas, or, in riveted members, hidden defects that are beneath fasteners or connection angles. Another issue is that it is difficult to determine the fatigue damage that a structure has experienced and the rate at which damage is accumulating due to uncertain history and load distribution in supporting members. A SHM system has several advantages that can overcome these limitations. SHM allows critical areas of the structure to be monitored more quantitatively under actual loading. The research needed to apply SHM to metallic structures was performed and a case study was carried out to show the potential of SHM-driven fatigue evaluation to assess the condition of critical transportation infrastructure and to guide inspectors to potential problem areas. This project combines the expertise in transportation infrastructure at New

  6. The Promoter of a Lysosomal Membrane Transporter Gene, CTNS, Binds Sp-1, Shares Sequences with the Promoter of an Adjacent Gene, CARKL, and Causes Cystinosis If Mutated in a Critical Region

    PubMed Central

    Phornphutkul, Chanika; Anikster, Yair; Huizing, Marjan; Braun, Paula; Brodie, Chaya; Chou, Janice Y.; Gahl, William A.

    2001-01-01

    Although >55 CTNS mutations occur in patients with the lysosomal storage disorder cystinosis, no regulatory mutations have been reported, because the promoter has not been defined. Using CAT reporter constructs of sequences 5′ to the CTNS coding sequence, we identified the CTNS promoter as the region encompassing nucleotides −316 to +1 with respect to the transcription start site. This region contains an Sp-1 regulatory element (GGCGGCG) at positions −299 to −293, which binds authentic Sp-1, as shown by electrophoretic-mobility–shift assays. Three patients exhibited mutations in the CTNS promoter. One patient with nephropathic cystinosis carried a −295 G→C substitution disrupting the Sp-1 motif, whereas two patients with ocular cystinosis displayed a −303 G→T substitution in one case and a −303 T insertion in the other case. Each mutation drastically reduced CAT activity when inserted into a reporter construct. Moreover, each failed either to cause a mobility shift when exposed to nuclear extract or to compete with the normal oligonucleotide’s mobility shift. The CTNS promoter region shares 41 nucleotides with the promoter region of an adjacent gene of unknown function, CARKL, whose start site is 501 bp from the CTNS start site. However, the patients’ CTNS promoter mutations have no effect on CARKL promoter activity. These findings suggest that the CTNS promoter region should be examined in patients with cystinosis who have fewer than two coding-sequence mutations. PMID:11505338

  7. The Structure of Gas-accreting Protoplanets and the Condition of the Critical Core Mass

    NASA Astrophysics Data System (ADS)

    Kanagawa, Kazuhiro D.; Fujimoto, Masayuki Y.

    2013-03-01

    In the core accretion model for the formation of gas giant planets, runaway gas accretion onto a core is the primary requisite, triggered when the core mass reaches a critical value. The recently revealed wide diversity of the extrasolar giant planets suggests the necessity to further the understanding of the conditions resulting in the critical core mass that initiates runaway accretion. We study the internal structure of protoplanets under hydrostatic and thermal equilibria represented in terms of a polytropic equation of state to investigate what factors determine and affect the critical core mass. We find that the protoplanets, embedded in protoplanetary disks, have the same configuration as red giants, characterized by the envelope of the centrally condensed type solution. Applying the theory of stellar structure with homology invariants, we demonstrate that there are three types of criteria for the critical core mass depending on the stiffness of polytrope and the nature of outer boundary condition. For the stiff polytropes of index N <= 3 with the Bondi radius as the outer boundary, the criterion governing the critical core mass occurs at the surface. For stiff polytropes with the Hill outer boundary and for soft polytropes of N > 3, this criterion acts at the bottom of gaseous envelope. Further, we elucidate the roles and effects of coexistent radiative and convective zones in the envelope of critical core mass. Based on the results, we discuss the relevance of Bondi and Hill surface conditions and explore the parameter dependences of critical core mass.

  8. THE STRUCTURE OF GAS-ACCRETING PROTOPLANETS AND THE CONDITION OF THE CRITICAL CORE MASS

    SciTech Connect

    Kanagawa, Kazuhiro D.; Fujimoto, Masayuki Y.

    2013-03-01

    In the core accretion model for the formation of gas giant planets, runaway gas accretion onto a core is the primary requisite, triggered when the core mass reaches a critical value. The recently revealed wide diversity of the extrasolar giant planets suggests the necessity to further the understanding of the conditions resulting in the critical core mass that initiates runaway accretion. We study the internal structure of protoplanets under hydrostatic and thermal equilibria represented in terms of a polytropic equation of state to investigate what factors determine and affect the critical core mass. We find that the protoplanets, embedded in protoplanetary disks, have the same configuration as red giants, characterized by the envelope of the centrally condensed type solution. Applying the theory of stellar structure with homology invariants, we demonstrate that there are three types of criteria for the critical core mass depending on the stiffness of polytrope and the nature of outer boundary condition. For the stiff polytropes of index N {<=} 3 with the Bondi radius as the outer boundary, the criterion governing the critical core mass occurs at the surface. For stiff polytropes with the Hill outer boundary and for soft polytropes of N > 3, this criterion acts at the bottom of gaseous envelope. Further, we elucidate the roles and effects of coexistent radiative and convective zones in the envelope of critical core mass. Based on the results, we discuss the relevance of Bondi and Hill surface conditions and explore the parameter dependences of critical core mass.

  9. Three-dimensional electrical structure of the crust and upper mantle in Ordos Block and adjacent area: Evidence of regional lithospheric modification

    NASA Astrophysics Data System (ADS)

    Dong, Hao; Wei, Wenbo; Ye, Gaofeng; Jin, Sheng; Jones, Alan G.; Jing, Jianen; Zhang, Letian; Xie, Chengliang; Zhang, Fan; Wang, Hui

    2014-06-01

    magnetotelluric (MT) data from project SINOPROBE were acquired and modeled, using three-dimensional (3D) MT inversion, to study the electrical structure of Ordos Block, a component of the North China Craton. For the first time, a high-resolution 3D resistivity model of the lithosphere is defined for the region. Contrary to what would be expected for a stable cratonic block, a prominent lithospheric conductive complex is revealed extending from the upper mantle to the mid-to-lower crust beneath the northern part of Ordos. Correlating well with results of seismic studies, the evidence from our independent magnetotelluric data supports regional modification of the lithosphere under the north Ordos and lithosphere thinning beneath Hetao Graben. The abnormally conductive structure may result from upwelling of mantle material in mid-to-late Mesozoic beneath the northern margin of the Ordos block.

  10. Radiation Doses to Structures Within and Adjacent to the Larynx are Correlated With Long-Term Diet- and Speech-Related Quality of Life

    SciTech Connect

    Dornfeld, Ken . E-mail: kenneth-dornfeld@uiowa.edu; Simmons, Joel R.; Karnell, Lucy; Karnell, Michael; Funk, Gerry; Yao Min; Wacha, Judith; Zimmerman, Bridget; Buatti, John M.

    2007-07-01

    Purpose: To test the hypothesis that radiation dose to key sites in the upper aerodigestive tract is associated with long-term functional outcome after (chemo)radiotherapy for head-and-neck cancers. Methods and Materials: This study examined the outcome for 27 patients treated with intensity-modulated radiotherapy for definitive management of their head-and-neck cancer who were disease free for at least 1 year after treatment. Head-and-neck cancer-specific quality of life (QoL) was assessed before treatment and at 1 year after treatment. Type of diet tolerated, presence of a feeding tube, and degree of weight loss 1 year after treatment were also used as outcome measures. Radiation doses delivered to various points along the upper aerodigestive tract, including base of tongue, lateral pharyngeal walls, and laryngeal structures, were determined from each treatment plan. Radiation doses for each of these points were tested for correlation with outcome measures. Results: Higher doses delivered to the aryepiglottic folds, false vocal cords, and lateral pharyngeal walls near the false cords correlated with a more restrictive diet, and higher doses to the aryepiglottic folds correlated with greater weight loss (p < 0.05) 1 year after therapy. Better posttreatment speech QoL scores were associated with lower doses delivered to structures within and surrounding the larynx. Conclusion: Our data show an inverse relationship between radiation dose delivered to laryngeal structures and speech and diet and QoL outcomes after definitive (chemo)radiation treatment. These findings suggest that efforts to deliver lower doses to laryngeal structures may improve outcomes after definitive (chemo)radiation therapy.

  11. Structural analysis of terrane accretions in the eastern Brooks Range and adjacent areas in central Alaska and Canada. Technical progress report No. 6

    SciTech Connect

    Coney, P.J.; Harms, T.A.

    1985-03-14

    Work on radiolarian separation and identification of samples from the Sylvester Allochthon is nearing completion. A preliminary chronostratigraphic chart showing the age range and lithologic type of all dated units has been drawn. The comparative petrography of lithologies from the Sylvester Allochthon and the Angayucham and Mosquito Terranes, and from deformed clastic rocks of the Venetie Terrane is being studied. Several preliminary structure sections have been drawn across the Sylvester Terrane. (ACR)

  12. Crustal structure of the eastern Algerian continental margin and adjacent deep basin: implications for late Cenozoic geodynamic evolution of the western Mediterranean

    NASA Astrophysics Data System (ADS)

    Bouyahiaoui, B.; Sage, F.; Abtout, A.; Klingelhoefer, F.; Yelles-Chaouche, K.; Schnürle, P.; Marok, A.; Déverchère, J.; Arab, M.; Galve, A.; Collot, J. Y.

    2015-06-01

    We determine the deep structure of the eastern Algerian basin and its southern margin in the Annaba region (easternmost Algeria), to better constrain the plate kinematic reconstruction in this region. This study is based on new geophysical data collected during the SPIRAL cruise in 2009, which included a wide-angle, 240-km-long, onshore-offshore seismic profile, multichannel seismic reflection lines and gravity and magnetic data, complemented by the available geophysical data for the study area. The analysis and modelling of the wide-angle seismic data including refracted and reflected arrival travel times, and integrated with the multichannel seismic reflection lines, reveal the detailed structure of an ocean-to-continent transition. In the deep basin, there is an ˜5.5-km-thick oceanic crust that is composed of two layers. The upper layer of the crust is defined by a high velocity gradient and P-wave velocities between 4.8 and 6.0 km s-1, from the top to the bottom. The lower crust is defined by a lower velocity gradient and P-wave velocity between 6.0 and 7.1 km s-1. The Poisson ratio in the lower crust deduced from S-wave modelling is 0.28, which indicates that the lower crust is composed mainly of gabbros. Below the continental edge, a typical continental crust with P-wave velocities between 5.2 and 7.0 km s-1, from the top to the bottom, shows a gradual seaward thinning of ˜15 km over an ˜35-km distance. This thinning is regularly distributed between the upper and lower crusts, and it characterizes a rifted margin, which has resulted from backarc extension at the rear of the Kabylian block, here represented by the Edough Massif at the shoreline. Above the continental basement, an ˜2-km-thick, pre-Messinian sediment layer with a complex internal structure is interpreted as allochthonous nappes of flysch backthrusted on the margin during the collision of Kabylia with the African margin. The crustal structure, moreover, provides evidence for Miocene

  13. Critical classroom structures for empowering students to participate in science discourse

    NASA Astrophysics Data System (ADS)

    Belleau, Shelly N.; Otero, Valerie K.

    2013-01-01

    We compared contextual characteristics that impacted the nature and substance of "summarizing discussions" in a physics and a chemistry classroom in an Hispanic-serving urban high school. Specifically, we evaluated structural components of curricula and classrooms necessary to develop a culture of critical inquiry. Using the Physics and Everyday Thinking (PET) curriculum in the physics course, we found that students demonstrated critical thinking, critical evaluation, and used laboratory evidence to support ideas in whole-class summarizing discussions. We then implemented a model similar to PET in the chemistry course. However, chemistry students' statements lacked evidence, opposition and critical evaluation, and required greater teacher facilitation. We hypothesize that the designed laboratories and the research basis of PET influenced the extent to which physics students verbalized substantive scientific thought, authentic appeals to evidence, and a sense of empowerment to participate in the classroom scientific community.

  14. Phylogeographic Structure of a Tethyan Relict Capparis spinosa (Capparaceae) Traces Pleistocene Geologic and Climatic Changes in the Western Himalayas, Tianshan Mountains, and Adjacent Desert Regions

    PubMed Central

    Wang, Qian; Zhang, Ming-Li; Yin, Lin-Ke

    2016-01-01

    Complex geological movements more or less affected or changed floristic structures, while the alternation of glacials and interglacials is presumed to have further shaped the present discontinuous genetic pattern of temperate plants. Here we consider Capparis spinosa, a xeromorphic Tethyan relict, to discuss its divergence pattern and explore how it responded in a stepwise fashion to Pleistocene geologic and climatic changes. 267 individuals from 31 populations were sampled and 24 haplotypes were identified, based on three cpDNA fragments (trnL-trnF, rps12-rpl20, and ndhF). SAMOVA clustered the 31 populations into 5 major clades. AMOVA suggests that gene flow between them might be restricted by vicariance. Molecular clock dating indicates that intraspecific divergence began in early Pleistocene, consistent with a time of intense uplift of the Himalaya and Tianshan Mountains, and intensified in mid-Pleistocene. Species distribution modeling suggests range reduction in the high mountains during the Last Glacial Maximum (LGM) as a result of cold climates when glacier advanced, while gorges at midelevations in Tianshan appear to have served as refugia. Populations of low-altitude desert regions, on the other hand, probably experienced only marginal impacts from glaciation, according to the high levels of genetic diversity. PMID:27314028

  15. Phylogeographic Structure of a Tethyan Relict Capparis spinosa (Capparaceae) Traces Pleistocene Geologic and Climatic Changes in the Western Himalayas, Tianshan Mountains, and Adjacent Desert Regions.

    PubMed

    Wang, Qian; Zhang, Ming-Li; Yin, Lin-Ke

    2016-01-01

    Complex geological movements more or less affected or changed floristic structures, while the alternation of glacials and interglacials is presumed to have further shaped the present discontinuous genetic pattern of temperate plants. Here we consider Capparis spinosa, a xeromorphic Tethyan relict, to discuss its divergence pattern and explore how it responded in a stepwise fashion to Pleistocene geologic and climatic changes. 267 individuals from 31 populations were sampled and 24 haplotypes were identified, based on three cpDNA fragments (trnL-trnF, rps12-rpl20, and ndhF). SAMOVA clustered the 31 populations into 5 major clades. AMOVA suggests that gene flow between them might be restricted by vicariance. Molecular clock dating indicates that intraspecific divergence began in early Pleistocene, consistent with a time of intense uplift of the Himalaya and Tianshan Mountains, and intensified in mid-Pleistocene. Species distribution modeling suggests range reduction in the high mountains during the Last Glacial Maximum (LGM) as a result of cold climates when glacier advanced, while gorges at midelevations in Tianshan appear to have served as refugia. Populations of low-altitude desert regions, on the other hand, probably experienced only marginal impacts from glaciation, according to the high levels of genetic diversity. PMID:27314028

  16. VIEW OF CONCRETE CHANNEL ADJACENT TO TUMALO FEED CANAL INTAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF CONCRETE CHANNEL ADJACENT TO TUMALO FEED CANAL INTAKE STRUCTURE (DOWNSTREAM SIDE). LOOKING EAST/NORTHEAST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

  17. Comparison of Family Structures in America and Nigeria: Lesson Plans on Critical Thinking.

    ERIC Educational Resources Information Center

    Dogbe, Korsi; Kellum, Ruthann

    Critical thinking skills must be emphasized in schools if excellence in education is to be realized. The lesson plans in this learning module were designed with this issue in mind. The lessons focus on the concept of family as a universal institution. But family structures may vary due to specific cultural history, rapid technological advancement,…

  18. Critical Multimodal Literacy: How Nigerian Female Students Critique Texts and Reconstruct Unequal Social Structures

    ERIC Educational Resources Information Center

    Ajayi, Lasisi

    2015-01-01

    This research investigates how three female Nigerian high school students were taught to deploy critical multimodal literacy to interrogate texts and reconstruct unequal social structures. A class of ninth-grade students in an all-women school was given instruction through the analysis of how multiple modes were used to represent meanings in…

  19. Reaching Agreement: The Structure & Pragmatics of Critical Care Nurses' Informal Argument

    ERIC Educational Resources Information Center

    Hagler, Debra A.; Brem, Sarah K.

    2008-01-01

    The hospital critical care unit provides an authentic, high-stakes setting for studying reasoning, argumentation, and discourse. In particular, it allows examination of structural and pragmatic features of informal collaborative argument created while participants are engaged in familiar, meaningful activities central to their work. The nursing…

  20. Geochemical insight into differences in the physical structures and dynamics of two adjacent maar lakes at Mt. Vulture volcano (southern Italy)

    NASA Astrophysics Data System (ADS)

    Caracausi, A.; Nicolosi, M.; Nuccio, P. M.; Favara, R.; Paternoster, M.; Rosciglione, A.

    2013-05-01

    report on the first geochemical investigation of the Monticchio maar lakes (Mt. Vulture volcano, southern Italy) covering an annual cycle that aimed at understanding the characteristic features of the physical structures and dynamics of the two lakes. We provide the first detailed description of the lakes based on high-resolution conductivity-temperature-depth (CTD) profiles, chemical and isotopic (H and O) compositions of the water, and the amounts of dissolved gases (e.g., He, Ar, CH4, and CO2). The combined data set reveals that the two lakes, which are separated by less than 200 m, exhibit different dynamics: one is a meromictic lake, where the waters are rich in biogenic and mantle-derived gases, while the other is a monomictic lake, which exhibits complete turnover of the water in winter and the release of dissolved gases. Our data strongly suggest that the differences in the dynamics of the two lakes are due to different density profiles affected by dissolved solutes, mainly Fe, which is strongly enriched in the deep water of the meromictic lake. A conceptual model of water balance was constructed based on the correlation between the chemical composition of the water and the hydrogen isotopic signature. Gas-rich groundwaters that feed both of the lakes and evaporation processes subsequently modify the water chemistry of the lakes. Our data highlight that no further potential hazardous accumulation of lethal gases is expected at the Monticchio lakes. Nevertheless, geochemical monitoring is needed to prevent the possibility of vigorous gas releases that have previously occurred in historical time.

  1. Sequence stratigraphy, structure, and tectonic history of the southwestern Ontong Java Plateau adjacent to the North Solomon Trench and Solomon Islands Arc

    NASA Astrophysics Data System (ADS)

    Phinney, Eric J.; Mann, Paul; Coffin, Millard F.; Shipley, Thomas H.

    1999-09-01

    The Ontong Java Plateau (OJP) is the largest and thickest oceanic plateau on Earth and one of the few oceanic plateaus actively converging on an island arc. We present velocity determinations and geologic interpretation of 2000 km of two-dimensional, multi-channel seismic data from the southwestern Ontong Java Plateau, North Solomon Trench, and northern Solomon Islands. We recognize three megasequences, ranging in age from early Cretaceous to Quaternary, on the basis of distinct interval velocities and seismic stratigraphic facies. Megasequence OJ1 is early Cretaceous, upper igneous crust of the OJP and correlates with basalt outcrops dated at 122-125 Ma on the island of Malaita. The top of the overlying megasequence OJ2, a late Cretaceous mudstone unit, had been identified by previous workers as the top of igneous basement. Seismic facies and correlation to distant Deep Sea Drilling Project/Ocean Drilling Program sites indicate that OJ2 was deposited in a moderately low-energy, marine environment near a fluctuating carbonate compensation depth that resulted in multiple periods of dissolution. OJ2 thins south of the Stewart Arch onto the Solomon Islands where it is correlated with the Kwaraae Mudstone Formation. Megasequence OJ3 is late Cretaceous through Quaternary pelagic cover which caps the Ontong Java Plateau; it thickens into the North Solomon Trench, and seismic facies suggest that OJ3 was deposited in a low-energy marine environment. We use seismic facies analysis, sediment thickness, structural observations, and quantitative plate reconstructions of the position of the OJP and Solomon Islands to propose a tectonic, magmatic, and sedimentary history of the southwestern Ontong Java Plateau. Prior to 125 Ma late Jurassic and early Cretaceous oceanic crust formed. From 125 to 122 Ma, the first mantle plume formed igneous crust (OJ1). Between 122 and 92 Ma, marine mudstone (OJ2 and Kwaraae mudstone of Malaita, Solomon Islands) was deposited on Ontong Java

  2. A look deep inside the a hillslope reveals a structured heterogeneity of isotopic reservoirs and distinct water use strategies for adjacent trees

    NASA Astrophysics Data System (ADS)

    Oshun, J.; Rempe, D. M.; Link, P.; Simonin, K. A.; Dietrich, W.; Dawson, T. E.; Fung, I.

    2012-12-01

    Whereas recent studies have begun to note the importance of weathered rock as a source of moisture for vegetation and, through transpiration, as a moderator of local and regional climate, no study has looked deeply into a hillslope in three-dimensions to explore dynamics in the hydrologic cycle and tree water use. Here, we use natural abundance stable isotope techniques to reveal distinct isotopic reservoirs within the hillslope, as well as quantify the movement of water from weathered rock and soil into vegetation. Our study site, at the Angelo Coast Range Reserve in Northern California, is a 4000 m2 unchanneled catchment that drains into Elder Creek, in the South Fork of the Eel River basin. Although average annual rainfall is 1900mm, 90% falls between October and May, forcing vegetation to find deep sources of moisture to survive the dry summer. An old-growth mixed conifer forest with trees as tall as 65 m grows on a 38° slope, with soils 10-60 cm thick underlain by vertically dipping, weathered turbidite sequences of the Coastal Franciscan Belt. A perched seasonally drains to unweathered bedrock. The water table fluctuates between 3 and 5 m below the surface near Elder Creek, and between 18 and 24 m below the surface at the hillslope divide. The site contains over 850 sensors monitoring the climatic variables and the movement of water through the subsurface, vegetation and into the atmosphere. Daily rainwater sampling during storm events from 2007-2012 shows a Local Meteoric Water Line, setting the context for our comparison of isotopic reservoirs. From Summer 2011 to Fall 2012, bi-weekly to tri-weekly samples were collected of tree xylem of over 30 individuals of Pseudotsuga menziesii, quercus agrifolia, arbutus menziesii, Umbellularia californica, Notholithocarpus densiflorus, acer macrophyllum, as well as from soil and rock to a depth of 1-1.3 m, and from the water table at 12 wells across the hillslope. Analysis reveals a structured heterogeneity of

  3. Adjacent Segment Pathology after Anterior Cervical Fusion

    PubMed Central

    Chung, Jae Yoon; Park, Jong-Beom; Seo, Hyoung-Yeon

    2016-01-01

    Anterior cervical fusion has become a standard of care for numerous pathologic conditions of the cervical spine. However, subsequent development of clinically significant disc disease at levels adjacent to fused discs is a serious long-term complication of this procedure. As more patients live longer after surgery, it is foreseeable that adjacent segment pathology (ASP) will develop in increasing numbers of patients. Also, ASP has been studied more intensively with the recent popularity of motion preservation technologies like total disc arthroplasty. The true nature and scope of ASP remains poorly understood. The etiology of ASP is most likely multifactorial. Various factors including altered biomechanical stresses, surgical disruption of soft tissue and the natural history of cervical disc disease contribute to the development of ASP. General factors associated with disc degeneration including gender, age, smoking and sports may play a role in the development of ASP. Postoperative sagittal alignment and type of surgery are also considered potential causes of ASP. Therefore, a spine surgeon must be particularly careful to avoid unnecessary disruption of the musculoligamentous structures, reduced risk of direct injury to the disc during dissection and maintain a safe margin between the plate edge and adjacent vertebrae during anterior cervical fusion. PMID:27340541

  4. Adjacent Segment Pathology after Anterior Cervical Fusion.

    PubMed

    Chung, Jae Yoon; Park, Jong-Beom; Seo, Hyoung-Yeon; Kim, Sung Kyu

    2016-06-01

    Anterior cervical fusion has become a standard of care for numerous pathologic conditions of the cervical spine. However, subsequent development of clinically significant disc disease at levels adjacent to fused discs is a serious long-term complication of this procedure. As more patients live longer after surgery, it is foreseeable that adjacent segment pathology (ASP) will develop in increasing numbers of patients. Also, ASP has been studied more intensively with the recent popularity of motion preservation technologies like total disc arthroplasty. The true nature and scope of ASP remains poorly understood. The etiology of ASP is most likely multifactorial. Various factors including altered biomechanical stresses, surgical disruption of soft tissue and the natural history of cervical disc disease contribute to the development of ASP. General factors associated with disc degeneration including gender, age, smoking and sports may play a role in the development of ASP. Postoperative sagittal alignment and type of surgery are also considered potential causes of ASP. Therefore, a spine surgeon must be particularly careful to avoid unnecessary disruption of the musculoligamentous structures, reduced risk of direct injury to the disc during dissection and maintain a safe margin between the plate edge and adjacent vertebrae during anterior cervical fusion. PMID:27340541

  5. Critical joints in large composite primary aircraft structures. Volume 2: Technology demonstration test report

    NASA Technical Reports Server (NTRS)

    Bunin, Bruce L.

    1985-01-01

    A program was conducted to develop the technology for critical structural joints in composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. The results of four large composite multirow bolted joint tests are presented. The tests were conducted to demonstrate the technology for critical joints in highly loaded composite structure and to verify the analytical methods that were developed throughout the program. The test consisted of a wing skin-stringer transition specimen representing a stringer runout and skin splice on the wing lower surface at the side of the fuselage attachment. All tests were static tension tests. The composite material was Toray T-300 fiber with Ciba-Geigy 914 resin in 10 mil tape form. The splice members were metallic, using combinations of aluminum and titanium. Discussions are given of the test article, instrumentation, test setup, test procedures, and test results for each of the four specimens. Some of the analytical predictions are also included.

  6. Brazed Joints Design and Allowables: Discuss Margins of Safety in Critical Brazed Structures

    NASA Technical Reports Server (NTRS)

    FLom, Yury

    2009-01-01

    This slide presentation tutorial discusses margins of safety in critical brazed structures. It reviews: (1) the present situation (2) definition of strength (3) margins of safety (4) design allowables (5) mechanical testing (6) failure criteria (7) design flowchart (8) braze gap (9) residual stresses and (10) delayed failures. This presentation addresses the strength of the brazed joints, the methods of mechanical testing, and our ability to evaluate the margins of safety of the brazed joints as it applies to the design of critical and expensive brazed assemblies.

  7. Stress Analysis of B-52B and B-52H Air-Launching Systems Failure-Critical Structural Components

    NASA Technical Reports Server (NTRS)

    Ko, William L.

    2005-01-01

    The operational life analysis of any airborne failure-critical structural component requires the stress-load equation, which relates the applied load to the maximum tangential tensile stress at the critical stress point. The failure-critical structural components identified are the B-52B Pegasus pylon adapter shackles, B-52B Pegasus pylon hooks, B-52H airplane pylon hooks, B-52H airplane front fittings, B-52H airplane rear pylon fitting, and the B-52H airplane pylon lower sway brace. Finite-element stress analysis was performed on the said structural components, and the critical stress point was located and the stress-load equation was established for each failure-critical structural component. The ultimate load, yield load, and proof load needed for operational life analysis were established for each failure-critical structural component.

  8. A Proposed Approach for Certification of Bonded Composite Repairs to Flight-Critical Airframe Structure

    NASA Astrophysics Data System (ADS)

    Baker, Alan A.

    2011-08-01

    This paper focuses on the difficult issue of the certification of adhesively bonded repairs in applications where credit has to be given to the patch for restoring residual strength in flight-critical structure. The scope of the paper includes both adhesively bonded composite repairs to composite components and composite repairs to metallic components. After discussing typical bonded repairs and, as a baseline, procedures currently used to certify new structure, a proposal is made which may constitute an acceptable basis for the structural certification of repairs. The key requirement is to demonstrate an acceptably low probability of patch disbonding during the remaining life of the structure. The focus is on one-off repairs where development of a comprehensive certification procedure based even on limited testing will be infeasible: Firstly, a decision process is undertaken to establish if there is indeed a certification issue. That is situations where flight safety depends on the structural integrity of the repair patch.

  9. Critical time span and nonlinear action structure of climatic atmosphere and ocean

    NASA Astrophysics Data System (ADS)

    Wang, Z. R.; Wu, D. X.; Chen, D. K.; Wu, H. D.; Song, X. J.; Zhang, Z. H.

    2002-07-01

    This paper studies the critical time span and the approximate nonlinear action structure of climatic atmosphere and ocean. The critical time span of the climatic atmosphere and ocean, which is related to the spatial resolution required, the strength of nonlinear action, and the calculation exactness, may represent the relative temporal scale of predictability. As far as the same characteristic spatial scale is concerned, the minimum critical time span of the ocean is about 9 times of that of atmosphere, several days or more. Usually, the stronger the nonlinear action, the shorter the critical time span with smooth changes of external forces. The approximate structure of nonlinear action of climatic atmosphere and ocean is: the nonlinear action decreases usually with increasing latitude, which is related to the role of the Coriolis force in fluid motion (forming geostrophic current); the nonlinear action changes with the anomalous cyclonic or anticyclonic circulation shear, for instance, when the strength of anomalous eastward zonal circulation is comparable to that of anomalous meridional circulation, the nonlinear action is the strongest; wind stress plus gradient forces enhance the nonlinear action, etc..

  10. Microtraps for neutral atoms using superconducting structures in the critical state

    SciTech Connect

    Emmert, A.; Brune, M.; Raimond, J.-M.; Nogues, G.; Lupascu, A.; Haroche, S.

    2009-12-15

    Recently demonstrated superconducting atom chips provide a platform for trapping atoms and coupling them to solid-state quantum systems. Controlling these devices requires a full understanding of the supercurrent distribution in the trapping structures. For type-II superconductors, this distribution is hysteretic in the critical state due to the partial penetration of the magnetic field in the thin superconducting film through pinned vortices. We report here an experimental observation of this memory effect. Our results are in good agreement with the predictions of the Bean model of the critical state without adjustable parameters. The memory effect allows to write and store permanent currents in micron-sized superconducting structures and paves the way toward engineered trapping potentials.

  11. High fidelity simulation of nucleate boiling and transition to critical heat flux on enhanced structures

    NASA Astrophysics Data System (ADS)

    Yazdani, Miad; Alahyari, Abbas; Radcliff, Thomas; Soteriou, Marios

    2015-11-01

    Surface enhancement is often is the primary approach for improved heat transfer performance of two-phase thermal systems particularly when they operate in nucleate boiling regime. This paper exploits the modeling capability developed by Yazdani et al. for simulation of nucleate boiling and transition to critical heat flux to study the nucleation phenomenon on various enhanced structures. The multi-scale of two-phase flow associated with boiling phenomena is addressed through combination of deterministic CFD for the macro-scale transport, asymptotic based representation of micro-layer, and stochastic representation of surface roughness so as to allow a high-fidelity simulation of boiling on an arbitrary surface. In addition, given the excessive complexity of surface structures often used for enhancement of boiling heat transfer, a phase-field-based method is developed to generate the structures where the numerical parameters in the phase-field model determine the topology of a given structure. The ``generated'' structure is then embedded into the two-phase flow model through virtual boundary method for the boiling simulation. The model is validated against experimental data for the boiling curve and the critical heat flux as well as nucleation and bubble dynamics characteristics.

  12. Target highlights in CASP9: Experimental target structures for the critical assessment of techniques for protein structure prediction.

    PubMed

    Kryshtafovych, Andriy; Moult, John; Bartual, Sergio G; Bazan, J Fernando; Berman, Helen; Casteel, Darren E; Christodoulou, Evangelos; Everett, John K; Hausmann, Jens; Heidebrecht, Tatjana; Hills, Tanya; Hui, Raymond; Hunt, John F; Seetharaman, Jayaraman; Joachimiak, Andrzej; Kennedy, Michael A; Kim, Choel; Lingel, Andreas; Michalska, Karolina; Montelione, Gaetano T; Otero, José M; Perrakis, Anastassis; Pizarro, Juan C; van Raaij, Mark J; Ramelot, Theresa A; Rousseau, Francois; Tong, Liang; Wernimont, Amy K; Young, Jasmine; Schwede, Torsten

    2011-01-01

    One goal of the CASP community wide experiment on the critical assessment of techniques for protein structure prediction is to identify the current state of the art in protein structure prediction and modeling. A fundamental principle of CASP is blind prediction on a set of relevant protein targets, that is, the participating computational methods are tested on a common set of experimental target proteins, for which the experimental structures are not known at the time of modeling. Therefore, the CASP experiment would not have been possible without broad support of the experimental protein structural biology community. In this article, several experimental groups discuss the structures of the proteins which they provided as prediction targets for CASP9, highlighting structural and functional peculiarities of these structures: the long tail fiber protein gp37 from bacteriophage T4, the cyclic GMP-dependent protein kinase Iβ dimerization/docking domain, the ectodomain of the JTB (jumping translocation breakpoint) transmembrane receptor, Autotaxin in complex with an inhibitor, the DNA-binding J-binding protein 1 domain essential for biosynthesis and maintenance of DNA base-J (β-D-glucosyl-hydroxymethyluracil) in Trypanosoma and Leishmania, an so far uncharacterized 73 residue domain from Ruminococcus gnavus with a fold typical for PDZ-like domains, a domain from the phycobilisome core-membrane linker phycobiliprotein ApcE from Synechocystis, the heat shock protein 90 activators PFC0360w and PFC0270w from Plasmodium falciparum, and 2-oxo-3-deoxygalactonate kinase from Klebsiella pneumoniae. PMID:22020785

  13. Structural insights of ZIP4 extracellular domain critical for optimal zinc transport

    NASA Astrophysics Data System (ADS)

    Zhang, Tuo; Sui, Dexin; Hu, Jian

    2016-06-01

    The ZIP zinc transporter family is responsible for zinc uptake from the extracellular milieu or intracellular vesicles. The LIV-1 subfamily, containing nine out of the 14 human ZIP proteins, is featured with a large extracellular domain (ECD). The critical role of the ECD is manifested by disease-causing mutations on ZIP4, a representative LIV-1 protein. Here we report the first crystal structure of a mammalian ZIP4-ECD, which reveals two structurally independent subdomains and an unprecedented dimer centred at the signature PAL motif. Structure-guided mutagenesis, cell-based zinc uptake assays and mapping of the disease-causing mutations indicate that the two subdomains play pivotal but distinct roles and that the bridging region connecting them is particularly important for ZIP4 function. These findings lead to working hypotheses on how ZIP4-ECD exerts critical functions in zinc transport. The conserved dimeric architecture in ZIP4-ECD is also demonstrated to be a common structural feature among the LIV-1 proteins.

  14. Structural insights of ZIP4 extracellular domain critical for optimal zinc transport

    PubMed Central

    Zhang, Tuo; Sui, Dexin; Hu, Jian

    2016-01-01

    The ZIP zinc transporter family is responsible for zinc uptake from the extracellular milieu or intracellular vesicles. The LIV-1 subfamily, containing nine out of the 14 human ZIP proteins, is featured with a large extracellular domain (ECD). The critical role of the ECD is manifested by disease-causing mutations on ZIP4, a representative LIV-1 protein. Here we report the first crystal structure of a mammalian ZIP4-ECD, which reveals two structurally independent subdomains and an unprecedented dimer centred at the signature PAL motif. Structure-guided mutagenesis, cell-based zinc uptake assays and mapping of the disease-causing mutations indicate that the two subdomains play pivotal but distinct roles and that the bridging region connecting them is particularly important for ZIP4 function. These findings lead to working hypotheses on how ZIP4-ECD exerts critical functions in zinc transport. The conserved dimeric architecture in ZIP4-ECD is also demonstrated to be a common structural feature among the LIV-1 proteins. PMID:27321477

  15. Characterization of the Hosgri Fault Zone and adjacent structures in the offshore Santa Maria Basin, south-central California: Chapter CC of Evolution of sedimentary basins/onshore oil and gas investigations - Santa Maria province

    USGS Publications Warehouse

    Willingham, C. Richard; Rietman, Jan D.; Heck, Ronald G.; Lettis, William R.

    2013-01-01

    The Hosgri Fault Zone trends subparallel to the south-central California coast for 110 km from north of Point Estero to south of Purisima Point and forms the eastern margin of the present offshore Santa Maria Basin. Knowledge of the attributes of the Hosgri Fault Zone is important for petroleum development, seismic engineering, and environmental planning in the region. Because it lies offshore along its entire reach, our characterizations of the Hosgri Fault Zone and adjacent structures are primarily based on the analysis of over 10,000 km of common-depth-point marine seismic reflection data collected from a 5,000-km2 area of the central and eastern parts of the offshore Santa Maria Basin. We describe and illustrate the along-strike and downdip geometry of the Hosgri Fault Zone over its entire length and provide examples of interpreted seismic reflection records and a map of the structural trends of the fault zone and adjacent structures in the eastern offshore Santa Maria Basin. The seismic data are integrated with offshore well and seafloor geologic data to describe the age and seismic appearance of offshore geologic units and marker horizons. We develop a basin-wide seismic velocity model for depth conversions and map three major unconformities along the eastern offshore Santa Maria Basin. Accompanying plates include maps that are also presented as figures in the report. Appendix A provides microfossil data from selected wells and appendix B includes uninterpreted copies of the annotated seismic record sections illustrated in the chapter. Features of the Hosgri Fault Zone documented in this investigation are suggestive of both lateral and reverse slip. Characteristics indicative of lateral slip include (1) the linear to curvilinear character of the mapped trace of the fault zone, (2) changes in structural trend along and across the fault zone that diminish in magnitude toward the ends of the fault zone, (3) localized compressional and extensional structures

  16. Intracomplex {pi}-{pi} stacking interaction between adjacent phenanthroline molecules in complexes with rare-earth nitrates: Crystal and molecular structures of bis(1,10-Phenanthroline)trinitratoytterbium and bis(1,10-Phenanthroline)trinitratolanthanum

    SciTech Connect

    Sadikov, G. G. Antsyshkina, A. S.; Rodnikova, M. N.; Solonina, I. A.

    2009-01-15

    Crystals of the compounds Yb(NO{sub 3}){sub 3}(Phen){sub 2} and La(NO{sub 3}){sub 3}(Phen){sub 2} (Phen = 1,10-phenanthroline) are investigated using X-ray diffraction. It is established that there exist two different crystalline modifications: the main modification (phase 1) is characteristic of all members of the isostructural series, and the second modification (phase 2) is observed only for the Eu, Er, and Yb elements. It is assumed that the stability and universality of main phase 1 are associated with the occurrence of the nonbonded {pi}-{pi} stacking interactions between the adjacent phenanthroline ligands in the complexes. The indication of the interactions is a distortion of the planar shape of the Phen molecule (the folding of the metallocycle along the N-N line with a folding angle of 11{sup o}-13{sup o} and its 'boomerang' distortion). The assumption regarding the {pi}-{pi} stacking interaction is very consistent with the shape of the ellipsoids of atomic thermal vibrations, as well as with the data obtained from thermography and IR spectroscopy. An analysis of the structures of a number of rare-earth compounds has demonstrated that the intracomplex {pi}-{pi} stacking interactions directly contribute to the formation of supramolecular associates in the crystals, such as molecular dimers, supramolecules, chain and layered ensembles, and framework systems.

  17. Reconstructing genome mixtures from partial adjacencies.

    PubMed

    Mahmoody, Ahmad; Kahn, Crystal L; Raphael, Benjamin J

    2012-01-01

    Many cancer genome sequencing efforts are underway with the goal of identifying the somatic mutations that drive cancer progression. A major difficulty in these studies is that tumors are typically heterogeneous, with individual cells in a tumor having different complements of somatic mutations. However, nearly all DNA sequencing technologies sequence DNA from multiple cells, thus resulting in measurement of mutations from a mixture of genomes. Genome rearrangements are a major class of somatic mutations in many tumors, and the novel adjacencies (i.e. breakpoints) resulting from these rearrangements are readily detected from DNA sequencing reads. However, the assignment of each rearrangement, or adjacency, to an individual cancer genome in the mixture is not known. Moreover, the quantity of DNA sequence reads may be insufficient to measure all rearrangements in all genomes in the tumor. Motivated by this application, we formulate the k-minimum completion problem (k-MCP). In this problem, we aim to reconstruct k genomes derived from a single reference genome, given partial information about the adjacencies present in the mixture of these genomes. We show that the 1-MCP is solvable in linear time in the cases where: (i) the measured, incomplete genome has a single circular or linear chromosome; (ii) there are no restrictions on the chromosomal content of the measured, incomplete genome. We also show that the k-MCP problem, for k ≥ 3 in general, and the 2-MCP problem with the double-cut-and-join (DCJ) distance are NP-complete, when there are no restriction on the chromosomal structure of the measured, incomplete genome. These results lay the foundation for future algorithmic studies of the k-MCP and the application of these algorithms to real cancer sequencing data. PMID:23282028

  18. Seismicity in Azerbaijan and Adjacent Caspian Sea

    SciTech Connect

    Panahi, Behrouz M.

    2006-03-23

    So far no general view on the geodynamic evolution of the Black Sea to the Caspian Sea region is elaborated. This is associated with the geological and structural complexities of the region revealed by geophysical, geochemical, petrologic, structural, and other studies. A clash of opinions on geodynamic conditions of the Caucasus region, sometimes mutually exclusive, can be explained by a simplified interpretation of the seismic data. In this paper I analyze available data on earthquake occurrences in Azerbaijan and the adjacent Caspian Sea region. The results of the analysis of macroseismic and instrumental data, seismic regime, and earthquake reoccurrence indicate that a level of seismicity in the region is moderate, and seismic event are concentrated in the shallow part of the lithosphere. Seismicity is mostly intra-plate, and spatial distribution of earthquake epicenters does not correlate with the plate boundaries.

  19. Methods for forewarning of critical condition changes in monitoring civil structures

    DOEpatents

    Abercrombie, Robert K.; Hively, Lee M.

    2013-04-02

    Sensor modules (12) including accelerometers (20) are placed on a physical structure (10) and tri-axial accelerometer data is converted to mechanical power (P) data (41) which then processed to provide a forewarning (57) of a critical event concerning the physical structure (10). The forewarning is based on a number of occurrences of a composite measure of dissimilarity (C.sub.i) exceeding a forewarning threshold over a defined sampling time; and a forewarning signal (58) is provided to a human observer through a visual, audible or tangible signal. A forewarning of a structural failure can also be provided based on a number of occurrences of (C.sub.i) above a failure value threshold.

  20. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  1. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  2. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  3. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  4. Critical evaluation on structural stiffness of porous cellular structure of cobalt chromium alloy

    NASA Astrophysics Data System (ADS)

    Abd Malek, N. M. S.; Mohamed, S. R.; Che Ghani, S. A.; Harun, W. S. Wan

    2015-12-01

    In order to improve the stiffness characteristics of orthopedic devices implants that mimic the mechanical behavior of bone need to be considered. With the capability of Additive layer manufacturing processes to produce orthopedic implants with tailored mechanical properties are needed. This paper discusses finite element (FE) analysis and mechanical characterization of porous medical grade cobalt chromium (CoCr) alloy in cubical structures with volume based porosity ranging between 60% to 80% produced using direct metal laser sintering (DMLS) process. ANSYS 14.0 FE modelling software was used to predict the effective elastic modulus of the samples and comparisons were made with the experimental data. The effective mechanical properties of porous samples that were determined by uniaxial compression testing show exponential decreasing trend with the increase in porosity. Finite element model shows good agreement with experimentally obtained stress-strain curve in the elastic regions. The models prove that numerical analysis of actual prosthesis implant can be computed particularly in load bearing condition

  5. Multiple actor-critic structures for continuous-time optimal control using input-output data.

    PubMed

    Song, Ruizhuo; Lewis, Frank; Wei, Qinglai; Zhang, Hua-Guang; Jiang, Zhong-Ping; Levine, Dan

    2015-04-01

    In industrial process control, there may be multiple performance objectives, depending on salient features of the input-output data. Aiming at this situation, this paper proposes multiple actor-critic structures to obtain the optimal control via input-output data for unknown nonlinear systems. The shunting inhibitory artificial neural network (SIANN) is used to classify the input-output data into one of several categories. Different performance measure functions may be defined for disparate categories. The approximate dynamic programming algorithm, which contains model module, critic network, and action network, is used to establish the optimal control in each category. A recurrent neural network (RNN) model is used to reconstruct the unknown system dynamics using input-output data. NNs are used to approximate the critic and action networks, respectively. It is proven that the model error and the closed unknown system are uniformly ultimately bounded. Simulation results demonstrate the performance of the proposed optimal control scheme for the unknown nonlinear system. PMID:25730830

  6. Critical behavior and magnetocaloric effect in layered structure Tb2C

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao; Matsuishi, Satoru; Hosono, Hideo

    2016-08-01

    The critical behavior and magnetocaloric effects of the layered structure Tb2C have been investigated using magnetization measurements around the Curie temperature. Analyzing temperature and field dependence of magnetization reveals that the Tb2C system undergoes a second-order magnetic phase transition at T C  =  266 K. Critical exponents obtained from modified Arrott, Kouvel–Fisher (KF) and scaling plots are consistent with each other. The critical exponents suggest that the magnetic phase transition in Tb2C can be described by the mean-field model. The exchange energy declines as J(r) ~ r ‑4.547, indicating that long-range interaction dominates the exchange interaction. Consequently, the field dependence magnetic entropy change (ΔS M) of Tb2C, calculated using the Maxwell relation, clearly demonstrates that the relationship between  ‑ΔS M and (H/T C)2/3 obeys the mean-field theory, supporting our conclusion of the ferromagnetism phase transition in Tb2C following the mean-field theory.

  7. Reduction of model structure bias in the prediction of critical source areas

    NASA Astrophysics Data System (ADS)

    Frey, M.; Stamm, C.; Schneider, M. K.; Reichert, P.

    2009-04-01

    Effective mitigation strategies to reduce the contamination of surface waters by agrochemicals rely on an accurate identification of critical source areas (CSA). We used a spatially distributed hydrological model to identify CSA in a small agricultural catchment in Switzerland. Since the knowledge about model parameters is coarse, prior predictions of CSA involve large uncertainties. We investigated to which degree river discharge data can constrain parameter values and improve the prediction. Thereby, we combined the prior knowledge used for the prior prediction with additional river discharge data within a Bayesian inference approach. In order to consider the effect of uncertainty in input data and in the model structure we formulated the likelihood function with an autoregressive error model additive to the river discharge calculated by the deterministic hydrological model. The additional information gained from river discharge data slightly reduced the width of some of the marginal parameter distributions and the prediction uncertainty for high or low-risk areas. However, the analysis of the statistical assumptions of the inference process revealed deficits in the model structure. Thus the base flow during dry periods tended to be overestimated. By making the percolation process water table dependent the base flow prediction could be improved. These improvements in model structure significantly reduced the model structure bias and thus improved the statistical basis of the probabilistic CSA prediction. Furthermore, the improved model structure led to a large constraint of the CSA prediction uncertainty.

  8. Population genetic structure of critically endangered salamander (Hynobius amjiensis) in China: recommendations for conservation.

    PubMed

    Yang, J; Chen, C S; Chen, S H; Ding, P; Fan, Z Y; Lu, Y W; Yu, L P; Lin, H D

    2016-01-01

    Amji's salamander (Hynobius amjiensis) is a critically endangered species (IUCN Red List), which is endemic to mainland China. In the present study, five haplotypes were genotyped for the mtDNA cyt b gene in 45 specimens from three populations. Relatively low levels of haplotype diversity (h = 0.524) and nucleotide diversity (π = 0.00532) were detected. Analyses of the phylogenic structure of H. amjiensis showed no evidence of major geographic partitions or substantial barriers to historical gene flow throughout the species' range. Two major phylogenetic haplotype groups were revealed, and were estimated to have diverged about 1.262 million years ago. Mismatch distribution analysis, neutrality tests, and Bayesian skyline plots revealed no evidence of dramatic changes in the effective population size. According to the SAMOVA and STRUCTURE analyses, H. amjiensis should be regarded as two different management units. PMID:27323156

  9. Critical Joints in Large Composite Primary Aircraft Structures. Volume 3: Ancillary Test Results

    NASA Technical Reports Server (NTRS)

    Bunin, Bruce L.; Sagui, R. L.

    1985-01-01

    A program was conducted to develop the technology for critical structural joints for composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. The results of a comprehensive ancillary test program are summarized, consisting of single-bolt composite joint specimens tested in a variety of configurations. These tests were conducted to characterize the strength and load deflection properties that are required for multirow joint analysis. The composite material was Toray 300 fiber and Ciba-Geigy 914 resin, in the form of 0.005 and 0.01 inch thick unidirectional tape. Tests were conducted in single and double shear for loaded and unloaded hole configurations under both tensile and compressive loading. Two different layup patterns were examined. All tests were conducted at room temperature. In addition, the results of NASA Standard Toughness Test (NASA RP 1092) are reported, which were conducted for several material systems.

  10. Environmental drivers of soil microbial community structure and function at the Avon River Critical Zone Observatory.

    PubMed

    Gleeson, Deirdre; Mathes, Falko; Farrell, Mark; Leopold, Matthias

    2016-11-15

    The Critical Zone is defined as the thin, permeable layer from the tops of the trees to the bottom of the bedrock that sustains terrestrial life on Earth. The geometry and shape of the various weathering zones are known as the critical zone architecture. At the centre of the Critical Zone are soils and the microorganisms that inhabit them. In Western Australia, the million-year-old stable weathering history and more recent lateral erosion during the past hundreds of thousands of years have created a geomorphic setting where deep weathering zones are now exposed on the surface along the flanks of many lateritic hills. These old weathering zones provide diverse physical and chemical properties that influence near surface pedologic conditions and thus likely shape current surface microbiology. Here, we present data derived from a small lateritic hill on the UWA Farm Ridgefield. Spatial soil sampling revealed the contrasting distribution patterns of simple soil parameters such as pH (CaCl2) and electric conductivity. These are clearly linked with underlying changes of the critical zone architecture and show a strong contrast with low values of pH3.3 at the top of the hill to pH5.3 at the bottom. These parameters were identified as major drivers of microbial spatial variability in terms of bacterial and archaeal community composition but not abundance. In addition, we used sensitive (14)C labelling to assess turnover of three model organic nitrogen compounds - an important biogeochemical functional trait relating to nutrient availability. Though generally rapid and in the order of rates reported elsewhere (t½<5h), some points in the sampling area showed greatly reduced turnover rates (t½>10h). In conclusion, we have shown that the weathering and erosion history of ancient Western Australia affects the surface pedology and has consequences for microbial community structure and function. PMID:27432724

  11. The critical protein interactions and structures that elicit growth deregulation in cancer and viral replication

    PubMed Central

    Ou, Horng D.; May, Andrew P.

    2010-01-01

    One of the greatest challenges in biomedicine is to define the critical targets and network interactions that are subverted to elicit growth deregulation in human cells. Understanding and developing rational treatments for cancer requires a definition of the key molecular targets and how they interact to elicit the complex growth deregulation phenotype. Viral proteins provide discerning and powerful probes to understand both how cells work and how they can be manipulated using a minimal number of components. The small DNA viruses have evolved to target inherent weaknesses in cellular protein interaction networks to hijack the cellular DNA and protein replication machinery. In the battle to escape the inevitability of senescence and programmed cell death, cancers have converged on similar mechanisms, through the acquisition and selection of somatic mutations that drive unchecked cellular replication in tumors. Understanding the dynamic mechanisms through which a minimal number of viral proteins promote host cells to undergo unscheduled and pathological replication is a powerful strategy to identify critical targets that are also disrupted in cancer. Viruses can therefore be used as tools to probe the system-wide protein-protein interactions and structures that drive growth deregulation in human cells. Ultimately this can provide a path for developing system context-dependent therapeutics. This review will describe ongoing experimental approaches using viruses to study pathways deregulated in cancer, with a particular focus on viral cellular protein-protein interactions and structures. PMID:21061422

  12. White Oak Creek Embayment time-critical CERCLA removal action sediment-retention structure

    SciTech Connect

    Not Available

    1992-09-01

    Over a 20-month period between September 1990 and April 1992, the Department of Energy (DOE), acting through Martin Marietta Energy Systems, Inc., managing contractor for the DOE Oak Ridge Field Office (DOE-OR), conducted a DOE-lead and DOE-funded time-critical removal action at the White Oak Creek Embayment (WOCE), pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The time-critical removal action specifically consisted of the design and construction of a sediment-retention structure across the mouth of WOCE to prevent off-site migration of sediments contaminated by cesium ([sup 137]Cs) into the Clinch River. Construction of a sediment-retention structure was completed in mid-April 1992. The purpose of this report is to meet the substantive requirements of 40 CFR 300.165 describing a complete report on the removal operation and the actions taken.'' This section of the NCP specifically addresses on-scene coordinator reports for the Environmental Protection Agency (EPA) Superfund-lead actions and includes several elements that are not applicable to this DOE-lead action. Only those sections that are pertinent and applicable are addressed in this final report.

  13. The critical protein interactions and structures that elicit growth deregulation in cancer and viral replication.

    PubMed

    Ou, Horng D; May, Andrew P; O'Shea, Clodagh C

    2011-01-01

    One of the greatest challenges in biomedicine is to define the critical targets and network interactions that are subverted to elicit growth deregulation in human cells. Understanding and developing rational treatments for cancer requires a definition of the key molecular targets and how they interact to elicit the complex growth deregulation phenotype. Viral proteins provide discerning and powerful probes to understand both how cells work and how they can be manipulated using a minimal number of components. The small DNA viruses have evolved to target inherent weaknesses in cellular protein interaction networks to hijack the cellular DNA and protein replication machinery. In the battle to escape the inevitability of senescence and programmed cell death, cancers have converged on similar mechanisms, through the acquisition and selection of somatic mutations that drive unchecked cellular replication in tumors. Understanding the dynamic mechanisms through which a minimal number of viral proteins promote host cells to undergo unscheduled and pathological replication is a powerful strategy to identify critical targets that are also disrupted in cancer. Viruses can therefore be used as tools to probe the system-wide protein-protein interactions and structures that drive growth deregulation in human cells. Ultimately this can provide a path for developing system context-dependent therapeutics. This review will describe ongoing experimental approaches using viruses to study pathways deregulated in cancer, with a particular focus on viral cellular protein-protein interactions and structures. PMID:21061422

  14. Function of Several Critical Amino Acids in Human Pyruvate Dehydrogenase Revealed by Its Structure

    NASA Technical Reports Server (NTRS)

    Korotchkina, Lioubov G.; Ciszak, E.; Patel, M.

    2004-01-01

    Pyruvate dehydrogenase (E1), an alpha 2 beta 2 tetramer, catalyzes the oxidative decarboxylation of pyruvate and reductive acetylation of lipoyl moieties of the dihydrolipoamide acetyltransferase. The roles of beta W135, alpha P188, alpha M181, alpha H15 and alpha R349 of E1 determined by kinetic analysis were reassessed by analyzing the three-dimensional structure of human E1. The residues identified above are found to play a structural role rather than being directly involved in catalysis: beta W135 is the center residue in the hydrophobic interaction between beta and beta' subunits; alpha P188 and alpha M181 are critical for the conformation of the TPP-binding motif and interaction between alpha and beta subunits; alpha H15, is necessary for the organization of the N-terminus of alpha and alpha'; subunits and alpha R349 supports the interaction of the C-terminus of the alpha subunits with the beta subunits. Analysis of several critical E1 residues confirms the importance of residues distant from the active site for subunit interactions and enzyme function.

  15. Can Student Nurse Critical Thinking Be Predicted from Perceptions of Structural Empowerment within the Undergraduate, Pre-Licensure Learning Environment?

    ERIC Educational Resources Information Center

    Caswell-Moore, Shelley P.

    2013-01-01

    The purpose of this study was to test a model using Rosabeth Kanter's theory (1977; 1993) of structural empowerment to determine if this model can predict student nurses' level of critical thinking. Major goals of nursing education are to cultivate graduates who can think critically with a keen sense of clinical judgment, and who can perform…

  16. Structural and functional neuroimaging in patients with Parkinson's disease and visual hallucinations: A critical review.

    PubMed

    Lenka, Abhishek; Jhunjhunwala, Ketan Ramakant; Saini, Jitender; Pal, Pramod Kumar

    2015-07-01

    Patients with Parkinson's disease (PD) may develop various non-motor symptoms (NMS) during the course of the illness and psychosis is one of the common NMS of PD. Visual hallucinations (VH) are the most common manifestation of psychosis in PD. The exact pathogenesis of VH in patients with PD is not clearly understood. Presence of VH has been described to be associated with rapid cognitive decline and increased nursing home placements in PD patients. A large number of structural and functional neuroimaging studies have been conducted to understand the cerebral basis of VH in PD. Structural imaging studies (Voxel Based Morphometry) have reported grey matter atrophy in multiple regions of the brain such as primary visual cortex, visual association cortex, limbic regions, cholinergic structures such as pedunculopontine nucleus and substantia innominata, which conclude possible alterations of brain regions associated with functions such as visuospatial-perception, attention control and memory. Most functional neuroimaging studies (functional MRI, positron emission tomography and single photon emission computerized tomography) have reported altered activation, blood flow, or reduced metabolism in both dorsal and ventral visual pathways, which probably indicates an alteration in the normal bottom-top visual processing and the presence of an aberrant top-down visual processing. This review critically analyzes the published studies on the structural and functional neuroimaging in PD patients with VH. PMID:25920541

  17. Optimization of tuned mass damper for adjacent buildings with equal properties

    NASA Astrophysics Data System (ADS)

    Bekdaş, Gebrail; Nigdeli, Sinan Melih

    2013-10-01

    During earthquakes, adjacent structures may collide to each other because of insufficient seismic gap. By using tuned mass dampers (TMD), the sway of adjacent buildings be reduced and pounding of structures is prevented. In this case, TMDs must be tuned according to the properties of adjacent structures in order to reduce seismic gap (maximum difference of displacements). Also, adjacent structures with equal properties may collide because live-loads on structures is not constant. Change of live-load affects seismic behavior of structures. In this paper, TMDs for adjacent structures with equal properties are optimized by using harmony search algorithm. The approach is effective to reduce the value of seismic gap needed for protection of structures.

  18. Microhabitat types promote the genetic structure of a micro-endemic and critically endangered mole salamander (Ambystoma leorae) of Central Mexico.

    PubMed

    Sunny, Armando; Monroy-Vilchis, Octavio; Reyna-Valencia, Carlos; Zarco-González, Martha M

    2014-01-01

    The reduced immigration and emigration rates resulting from the lack of landscape connectivity of patches and the hospitality of the intervening matrix could favor the loss of alleles through genetic drift and an increased chance of inbreeding. In order for isolated populations to maintain sufficient levels of genetic diversity and adapt to environmental changes, one important conservation goal must be to preserve or reestablish connectivity among patches in a fragmented landscape. We studied the last known population of Ambystoma leorae, an endemic and critically threatened species. The aims of this study were: (1) to assess the demographic parameters of A. leorae and to distinguish and characterize the microhabitats in the river, (2) to determine the number of existing genetic groups or demes of A. leorae and to describe possible relationships between microhabitats types and demes, (3) to determine gene flow between demes, and (4) to search for geographic locations of genetic discontinuities that limit gene flow between demes. We found three types of microhabitats and three genetically differentiated subpopulations with a significant level of genetic structure. In addition, we found slight genetic barriers. Our results suggest that mole salamander's species are very sensitive to microhabitat features and relatively narrow obstacles in their path. The estimates of bidirectional gene flow are consistent with the pattern of a stepping stone model between demes, where migration occurs between adjacent demes, but there is low gene flow between distant demes. We can also conclude that there is a positive correlation between microhabitats and genetic structure in this population. PMID:25076052

  19. Estimation of critical forest structure metrics through the spatial analysis of airborne laser scanner data

    NASA Astrophysics Data System (ADS)

    Andersen, Hans-Erik

    The effective management of complex forest ecosystems depends on quantification of critical forest structure components. Three important structural components include vertical foliage distribution, tree size distribution, and horizontal spatial pattern. Active remote sensing technologies, such as LIght Detection And Ranging (LIDAR), are well-suited for analysis of three-dimensional forest structure. In this research, a methodology was developed to relate the spatial distribution and pattern of LIDAR data to forest structure metrics, through implementation of stochastic modeling and image analysis techniques. An original approach to estimating the vertical distribution of canopy foliage using multiple return LIDAR is presented. A probabilistically transformed estimate of the canopy foliage profile is derived to approximate model-based profiles developed from field data. Plot-wise goodness-of-fit tests showed the transformed LIDAR-based profile provided an improved estimate of the model-based profile. A methodology is presented for estimating canopy cover and LAI using LIDAR. Two machine vision algorithms, based upon mathematical morphology and Bayesian object recognition, were developed for the spatially-explicit analysis of tree size distributions using high-density LIDAR. The mathematical morphological analysis of the canopy surface model yielded estimates of tree height that were correlated with field-based measurements (r = 0.80). The simulation-based Bayesian object recognition algorithm provided inferences on plot-wise functionals, including Lorey's height, basal area, stem number and volume. A comparison of the maximum a posteriori estimate with field-based measurements showed mean errors (+/-1 st.dev.) for: Height 3.9 +/- 8.9 ft; DBH 0.4 +/- 3.2 in; stem volume 6.9 +/- 38.8 ft3 (n = 17). A methodology was developed to quantify the error budget in automated individual tree-based forest surveys. To investigate horizontal spatial patterns, a novel approach to

  20. Damage criticality and inspection concerns of composite-metallic aircraft structures under blunt impact

    NASA Astrophysics Data System (ADS)

    Zou, D.; Haack, C.; Bishop, P.; Bezabeh, A.

    2015-04-01

    Composite aircraft structures such as fuselage and wings are subject to impact from many sources. Ground service equipment (GSE) vehicles are regarded as realistic sources of blunt impact damage, where the protective soft rubber is used. With the use of composite materials, blunt impact damage is of special interest, since potential significant structural damage may be barely visible or invisible on the structure's outer surface. Such impact can result in local or non-local damage, in terms of internal delamination in skin, interfacial delamination between stiffeners and skin, and fracture of internal reinforced component such as stringers and frames. The consequences of these events result in aircraft damage, delays, and financial cost to the industry. Therefore, it is necessary to understand the criticality of damage under this impact and provide reliable recommendations for safety and inspection technologies. This investigation concerns a composite-metallic 4-hat-stiffened and 5-frame panel, designed to represent a fuselage structure panel generic to the new generation of composite aircraft. The test fixtures were developed based on the correlation between finite element analyses of the panel model and the barrel model. Three static tests at certain amount of impact energy were performed, in order to improve the understanding of the influence of the variation in shear ties, and the added rotational stiffness. The results of this research demonstrated low velocity high mass impacts on composite aircraft fuselages beyond 82.1 kN of impact load, which may cause extensive internal structural damage without clear visual detectability on the external skin surface.

  1. Structural Identifiability of Systems Biology Models: A Critical Comparison of Methods

    PubMed Central

    Chis, Oana-Teodora; Banga, Julio R.; Balsa-Canto, Eva

    2011-01-01

    Analysing the properties of a biological system through in silico experimentation requires a satisfactory mathematical representation of the system including accurate values of the model parameters. Fortunately, modern experimental techniques allow obtaining time-series data of appropriate quality which may then be used to estimate unknown parameters. However, in many cases, a subset of those parameters may not be uniquely estimated, independently of the experimental data available or the numerical techniques used for estimation. This lack of identifiability is related to the structure of the model, i.e. the system dynamics plus the observation function. Despite the interest in knowing a priori whether there is any chance of uniquely estimating all model unknown parameters, the structural identifiability analysis for general non-linear dynamic models is still an open question. There is no method amenable to every model, thus at some point we have to face the selection of one of the possibilities. This work presents a critical comparison of the currently available techniques. To this end, we perform the structural identifiability analysis of a collection of biological models. The results reveal that the generating series approach, in combination with identifiability tableaus, offers the most advantageous compromise among range of applicability, computational complexity and information provided. PMID:22132135

  2. Geographic variation and genetic structure in the Bahama Oriole (Icterus northropi), a critically endangered synanthropic species

    PubMed Central

    Person, Carl; Hayes, William K.

    2015-01-01

    Bird species may exhibit unexpected population structuring over small distances, with gene flow restricted by geographic features such as water or mountains. The Bahama Oriole (Icterus northropi) is a critically endangered, synanthropic island endemic with a declining population of fewer than 300 individuals. It now remains only on Andros Island (The Bahamas), which is riddled with waterways that past studies assumed did not hinder gene flow. We examined 1,858 base pairs of mitochondrial DNA sequenced from four gene regions in 14 birds (roughly 5% of the remaining population) found on the largest land masses of Andros Island (North Andros and Mangrove Cay/South Andros). We sought to discern genetic structuring between the remaining subpopulations and its relationship to current conservation concerns. Four unique haplotypes were identified, with only one shared between the two subpopulations. Nucleotide and haplotype diversity were higher for the North Andros subpopulation than for the Mangrove Cay/South Andros subpopulation. Analysis of molecular variance (AMOVA) yielded a Wright’s fixation index (Fst) of 0.60 (PFst = 0.016), with 40.2% of the molecular variation explained by within-population differences and 59.8% by among-population differences. Based on the mitochondrial regions examined in this study, we suggest the extant subpopulations of Bahama Oriole exhibit significant population structuring over short distances, consistent with some other non-migratory tropical songbird species. PMID:26644974

  3. The RGD finger of Del-1 is a unique structural feature critical for integrin binding

    SciTech Connect

    Schürpf, Thomas; Chen, Qiang; Liu, Jin-huan; Wang, Rui; Springer, Timothy A.; Wang, Jia-huai

    2012-11-13

    Developmental endothelial cell locus-1 (Del-1) glycoprotein is secreted by endothelial cells and a subset of macrophages. Del-1 plays a regulatory role in vascular remodeling and functions in innate immunity through interaction with integrin {alpha}{sub V}{beta}{sub 3}. Del-1 contains 3 epidermal growth factor (EGF)-like repeats and 2 discoidin-like domains. An Arg-Gly-Asp (RGD) motif in the second EGF domain (EGF2) mediates adhesion by endothelial cells and phagocytes. We report the crystal structure of its 3 EGF domains. The RGD motif of EGF2 forms a type II' {beta} turn at the tip of a long protruding loop, dubbed the RGD finger. Whereas EGF2 and EGF3 constitute a rigid rod via an interdomain calcium ion binding site, the long linker between EGF1 and EGF2 lends considerable flexibility to EGF1. Two unique O-linked glycans and 1 N-linked glycan locate to the opposite side of EGF2 from the RGD motif. These structural features favor integrin binding of the RGD finger. Mutagenesis data confirm the importance of having the RGD motif at the tip of the RGD finger. A database search for EGF domain sequences shows that this RGD finger is likely an evolutionary insertion and unique to the EGF domain of Del-1 and its homologue milk fat globule-EGF 8. The RGD finger of Del-1 is a unique structural feature critical for integrin binding.

  4. Geographic variation and genetic structure in the Bahama Oriole (Icterus northropi), a critically endangered synanthropic species.

    PubMed

    Price, Melissa R; Person, Carl; Hayes, William K

    2015-01-01

    Bird species may exhibit unexpected population structuring over small distances, with gene flow restricted by geographic features such as water or mountains. The Bahama Oriole (Icterus northropi) is a critically endangered, synanthropic island endemic with a declining population of fewer than 300 individuals. It now remains only on Andros Island (The Bahamas), which is riddled with waterways that past studies assumed did not hinder gene flow. We examined 1,858 base pairs of mitochondrial DNA sequenced from four gene regions in 14 birds (roughly 5% of the remaining population) found on the largest land masses of Andros Island (North Andros and Mangrove Cay/South Andros). We sought to discern genetic structuring between the remaining subpopulations and its relationship to current conservation concerns. Four unique haplotypes were identified, with only one shared between the two subpopulations. Nucleotide and haplotype diversity were higher for the North Andros subpopulation than for the Mangrove Cay/South Andros subpopulation. Analysis of molecular variance (AMOVA) yielded a Wright's fixation index (F st) of 0.60 (P Fst = 0.016), with 40.2% of the molecular variation explained by within-population differences and 59.8% by among-population differences. Based on the mitochondrial regions examined in this study, we suggest the extant subpopulations of Bahama Oriole exhibit significant population structuring over short distances, consistent with some other non-migratory tropical songbird species. PMID:26644974

  5. Tailoring of SmCo5 for optimal structure, magnetic anisotropy, and reduced criticality

    NASA Astrophysics Data System (ADS)

    Paudyal, Durga; Chouhan, R.; Gschneidner, K. A., Jr.

    SmCo5 orms hexagonal CaCu5-type structure with three non-equivalent sites: Sm (1a), Co (2c), and Co (3g). Sm lies in the middle of the Co (2c) hexagonal layers. Advanced density functional theory calculations employing Hubbard model show crystal field split localized Sm 4f states, which are responsible for the large part of the magnetic anisotropy exhibited by this system. In addition, the hexagonal Co (2c) layers help enhancing the anisotropy. Due to the partially quenched Sm 4f orbital moment, there is a net Sm 4f moment, which also helps enhancing magnetic moment. The substitution of some of the Sm sites by Nd adds Nd 4f multiplet thereby enhancing crystal field split 4f states and overall magnetic moment. The substitution of Co (2c) by Fe is preferred over Co (3g) but the compound becomes chemically unstable. The criticality issues could be addressed by substituting abundant Ce. This work is supported by the Critical Materials Institute, an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office.

  6. Crustal architecture and deep structure of the Namibian continental shelf and adjacent oceanic basins around the landfall of Walvis Ridge from wide-angle seismic and marine magnetotelluric data

    NASA Astrophysics Data System (ADS)

    Planert, L.; Behrmann, J.; Jegen, M.; Heincke, B.; Jokat, W.; Bialas, J.; Marti, A.

    2012-12-01

    results for a marine magnetotelluric profile. Tomographic analysis of the seismic data reveals the velocity structure of the crust down into the uppermost mantle. The probably most striking feature of our models is the sharp lateral transition in crustal structure and thickness associated with the northern boundary zone of Walvis Ridge towards the Angola Basin. Here, the rather thin oceanic crust in the basin lies opposite to the ~35 km thick igneous crustal root founding the highest elevated northern portions of Walvis Ridge. In contrast, the southern termination of Walvis Ridge and the corresponding transition towards the adjacent 25-30 km thick crustal portions further south is much more subdued. Due to the presence of a high-velocity (6.5-7.2 km/s) lower crust we argue that the Namibian shelf south of Walvis Ridge comprises a transitional igneous origin. We suggest that the northern boundary zone close to the landfall of Walvis Ridge represents an important transtensional tectonic feature which may have provoked the preferential extraction of melts into the footwall of this structure.

  7. Analytical description for the critical fixations of evolutionary coordination games on finite complex structured populations

    NASA Astrophysics Data System (ADS)

    Zhang, Liye; Zou, Yong; Guan, Shuguang; Liu, Zonghua

    2015-04-01

    Evolutionary game theory is crucial to capturing the characteristic interaction patterns among selfish individuals. In a population of coordination games of two strategies, one of the central problems is to determine the fixation probability that the system reaches a state of networkwide of only one strategy, and the corresponding expectation times. The deterministic replicator equations predict the critical value of initial density of one strategy, which separates the two absorbing states of the system. However, numerical estimations of this separatrix show large deviations from the theory in finite populations. Here we provide a stochastic treatment of this dynamic process on complex networks of finite sizes as Markov processes, showing the evolutionary time explicitly. We describe analytically the effects of network structures on the intermediate fixations as observed in numerical simulations. Our theoretical predictions are validated by various simulations on both random and scale free networks. Therefore, our stochastic framework can be helpful in dealing with other networked game dynamics.

  8. Imaging the 'mosaic' structure of ICB by pre-critical PcP-PKiKP phases

    NASA Astrophysics Data System (ADS)

    Shen, Z.; Ai, Y.; He, Y.; Jiang, M.

    2013-12-01

    Slowly growing in highly homogeneous liquid outer core, earth inner core has been thought lacking of significant heterogeneous structure. However, seismic observations of recent decades have demonstrated hierarchical heterogeneous structure as hemispherical longitudinal dichotomy superimposed by coda-generating scattering heterogeneities with diameters of tens of kilometers, indicating complicity of inner core crystallizing environment and related dynamic process. Furthermore, as boundary of phase transform and energy-material exchange, ICB has been unveiled as patchy mosaic-like surface, based on high variety of global pre-critical PcP-PKiKP amplitude ratios. From dense arrays deployed across East and South China in the year 2005~2011 and 13 earthquakes of west Pacific subduction zone, we have collected over 150 clear pre-critical PcP-PKiKP waveforms of epicenter distance range between 14~35°, providing an ideal sampling to detect possible ICB regional variation of the East Asia area. The amplitude observation exhibits good geographical coherency which is characterized as region of high density contrast (>1.0g/cm3) located beneath East China demarcated by the low (around or lower than 0.6g/cm3) on the periphery, except the southeastward stretching. This contrasting depicts vividly the claimed 'mosaic' ICB and bridges the gap between hemispherical (~1000km order) and scatter-inducing (~10km order or less) scales of heterogeneity. On the other hand, travel time residues of PcP-PKiKP in our study reveal a complex pattern north of ~18°N perturbed strongly by shallow (crust and mantle) anomalies and remarkable delay of PKiKP in the south, implicating effects of undetected ULVZ below Celebes Sea. This research is supported by the National Natural Science Foundation of China (NSFC, grant 90914011, 41125015). Distribution of PcP-PKiKP relative amplitude ratio

  9. Nonlinear spin wave coupling in adjacent magnonic crystals

    NASA Astrophysics Data System (ADS)

    Sadovnikov, A. V.; Beginin, E. N.; Morozova, M. A.; Sharaevskii, Yu. P.; Grishin, S. V.; Sheshukova, S. E.; Nikitov, S. A.

    2016-07-01

    We have experimentally studied the coupling of spin waves in the adjacent magnonic crystals. Space- and time-resolved Brillouin light-scattering spectroscopy is used to demonstrate the frequency and intensity dependent spin-wave energy exchange between the side-coupled magnonic crystals. The experiments and the numerical simulation of spin wave propagation in the coupled periodic structures show that the nonlinear phase shift of spin wave in the adjacent magnonic crystals leads to the nonlinear switching regime at the frequencies near the forbidden magnonic gap. The proposed side-coupled magnonic crystals represent a significant advance towards the all-magnonic signal processing in the integrated magnonic circuits.

  10. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR...-managing agencies on adjacent lands (both public and private)....

  11. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR...-managing agencies on adjacent lands (both public and private)....

  12. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of off-road vehicle use on Reclamation lands will...

  13. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR...-managing agencies on adjacent lands (both public and private)....

  14. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  15. Structure of the dimerization domain of DiGeorge critical region 8

    SciTech Connect

    Senturia, R.; Faller, M.; Yin, S.; Loo, J.A.; Cascio, D.; Sawaya, M.R.; Hwang, D.; Clubb, R.T.; Guo, F.

    2010-09-27

    Maturation of microRNAs (miRNAs, {approx}22nt) from long primary transcripts [primary miRNAs (pri-miRNAs)] is regulated during development and is altered in diseases such as cancer. The first processing step is a cleavage mediated by the Microprocessor complex containing the Drosha nuclease and the RNA-binding protein DiGeorge critical region 8 (DGCR8). We previously reported that dimeric DGCR8 binds heme and that the heme-bound DGCR8 is more active than the heme-free form. Here, we identified a conserved dimerization domain in DGCR8. Our crystal structure of this domain (residues 298-352) at 1.7 {angstrom} resolution demonstrates a previously unknown use of a WW motif as a platform for extensive dimerization interactions. The dimerization domain of DGCR8 is embedded in an independently folded heme-binding domain and directly contributes to association with heme. Heme-binding-deficient DGCR8 mutants have reduced pri-miRNA processing activity in vitro. Our study provides structural and biochemical bases for understanding how dimerization and heme binding of DGCR8 may contribute to regulation of miRNA biogenesis.

  16. Structural models of human apolipoprotein A-I: a critical analysis and review.

    PubMed

    Brouillette, C G; Anantharamaiah, G M; Engler, J A; Borhani, D W

    2001-03-30

    Human apolipoprotein (apo) A-I has been the subject of intense investigation because of its well-documented anti-atherogenic properties. About 70% of the protein found in high density lipoprotein complexes is apo A-I, a molecule that contains a series of highly homologous amphipathic alpha-helices. A number of significant experimental observations have allowed increasing sophisticated structural models for both the lipid-bound and the lipid-free forms of the apo A-I molecule to be tested critically. It seems clear, for example, that interactions between amphipathic domains in apo A-I may be crucial to understanding the dynamic nature of the molecule and the pathways by which the lipid-free molecule binds to lipid, both in a discoidal and a spherical particle. The state of the art of these structural studies is discussed and placed in context with current models and concepts of the physiological role of apo A-I and high-density lipoprotein in atherosclerosis and lipid metabolism. PMID:11278170

  17. Molecular disorganization of axons adjacent to human lacunar infarcts

    PubMed Central

    Lee, Monica D.; Tung, Spencer; Vinters, Harry V.; Carmichael, S. Thomas

    2015-01-01

    Cerebral microvascular disease predominantly affects brain white matter and deep grey matter, resulting in ischaemic damage that ranges from lacunar infarcts to white matter hyperintensities seen on magnetic resonance imaging. These lesions are common and result in both clinical stroke syndromes and accumulate over time, resulting in cognitive deficits and dementia. Magnetic resonance imaging studies suggest that these lesions progress over time, accumulate adjacent to prior lesions and have a penumbral region susceptible to further injury. The pathological correlates of this adjacent injury in surviving myelinated axons have not been previously defined. In this study, we sought to determine the molecular organization of axons in tissue adjacent to lacunar infarcts and in the regions surrounding microinfarcts, by determining critical elements in axonal function: the morphology and length of node of Ranvier segments and adjacent paranodal segments. We examined post-mortem brain tissue from six patients with lacunar infarcts and tissue from two patients with autosomal dominant retinal vasculopathy and cerebral leukoencephalopathy (previously known as hereditary endotheliopathy with retinopathy, nephropathy and stroke) who accumulate progressive white matter ischaemic lesions in the form of lacunar and microinfarcts. In axons adjacent to lacunar infarcts yet extending up to 150% of the infarct diameter away, both nodal and paranodal length increase by ∼20% and 80%, respectively, reflecting a loss of normal cell-cell adhesion and signalling between axons and oligodendrocytes. Using premorbid magnetic resonance images, brain regions from patients with retinal vasculopathy and cerebral leukoencephalopathy that harboured periventricular white matter hyperintensities were selected and the molecular organization of axons was determined within these regions. As in regions adjacent to lacunar infarcts, nodal and paranodal length in white matter of these patients is

  18. Causes and consequences of fine-scale population structure in a critically endangered freshwater seal

    PubMed Central

    2014-01-01

    Background Small, genetically uniform populations may face an elevated risk of extinction due to reduced environmental adaptability and individual fitness. Fragmentation can intensify these genetic adversities and, therefore, dispersal and gene flow among subpopulations within an isolated population is often essential for maintaining its viability. Using microsatellite and mtDNA data, we examined genetic diversity, spatial differentiation, interregional gene flow, and effective population sizes in the critically endangered Saimaa ringed seal (Phoca hispida saimensis), which is endemic to the large but highly fragmented Lake Saimaa in southeastern Finland. Results Microsatellite diversity within the subspecies (HE = 0.36) ranks among the lowest thus far recorded within the order Pinnipedia, with signs of ongoing loss of individual heterozygosity, reflecting very low effective subpopulation sizes. Bayesian assignment analyses of the microsatellite data revealed clear genetic differentiation among the main breeding areas, but interregional structuring was substantially weaker in biparentally inherited microsatellites (FST = 0.107) than in maternally inherited mtDNA (FST = 0.444), indicating a sevenfold difference in the gene flow mediated by males versus females. Conclusions Genetic structuring in the population appears to arise from the joint effects of multiple factors, including small effective subpopulation sizes, a fragmented lacustrine habitat, and behavioural dispersal limitation. The fine-scale differentiation found in the landlocked Saimaa ringed seal is especially surprising when contrasted with marine ringed seals, which often exhibit near-panmixia among subpopulations separated by hundreds or even thousands of kilometres. Our results demonstrate that population structures of endangered animals cannot be predicted based on data on even closely related species or subspecies. PMID:25005257

  19. Critical Care Delivery: The Importance of Process of Care and ICU Structure to Improved Outcomes: An Update From the American College of Critical Care Medicine Task Force on Models of Critical Care.

    PubMed

    Weled, Barry J; Adzhigirey, Lana A; Hodgman, Tudy M; Brilli, Richard J; Spevetz, Antoinette; Kline, Andrea M; Montgomery, Vicki L; Puri, Nitin; Tisherman, Samuel A; Vespa, Paul M; Pronovost, Peter J; Rainey, Thomas G; Patterson, Andrew J; Wheeler, Derek S

    2015-07-01

    In 2001, the Society of Critical Care Medicine published practice model guidelines that focused on the delivery of critical care and the roles of different ICU team members. An exhaustive review of the additional literature published since the last guideline has demonstrated that both the structure and process of care in the ICU are important for achieving optimal patient outcomes. Since the publication of the original guideline, several authorities have recognized that improvements in the processes of care, ICU structure, and the use of quality improvement science methodologies can beneficially impact patient outcomes and reduce costs. Herein, we summarize findings of the American College of Critical Care Medicine Task Force on Models of Critical Care: 1) An intensivist-led, high-performing, multidisciplinary team dedicated to the ICU is an integral part of effective care delivery; 2) Process improvement is the backbone of achieving high-quality ICU outcomes; 3) Standardized protocols including care bundles and order sets to facilitate measurable processes and outcomes should be used and further developed in the ICU setting; and 4) Institutional support for comprehensive quality improvement programs as well as tele-ICU programs should be provided. PMID:25803647

  20. SU-F-19A-03: Dosimetric Advantages in Critical Structure Dose Sparing by Using a Multichannel Cylinder in High Dose Rate Brachytherapy to Treat Vaginal Cuff Cancer

    SciTech Connect

    Syh, J; Syh, J; Patel, B; Zhang, J; Wu, H; Rosen, L

    2014-06-15

    Purpose: The multichannel cylindrical vaginal applicator is a variation of traditional single channel cylindrical vaginal applicator. The multichannel applicator has additional peripheral channels that provide more flexibility in the planning process. The dosimetric advantage is to reduce dose to adjacent organ at risk (OAR) such as bladder and rectum while maintaining target coverage with the dose optimization from additional channels. Methods: Vaginal HDR brachytherapy plans are all CT based. CT images were acquired in 2 mm thickness to keep integrity of cylinder contouring. The CTV of 5mm Rind with prescribed treatment length was reconstructed from 5mm expansion of inserted cylinder. The goal was 95% of CTV covered by 95% of prescribed dose in both single channel planning (SCP)and multichannel planning (MCP) before proceeding any further optimization for dose reduction to critical structures with emphasis on D2cc and V2Gy . Results: This study demonstrated noticeable dose reduction to OAR was apparent in multichannel plans. The D2cc of the rectum and bladder were showing the reduced dose for multichannel versus single channel. The V2Gy of the rectum was 93.72% and 83.79% (p=0.007) for single channel and multichannel respectively (Figure 1 and Table 1). To assure adequate coverage to target while reducing the dose to the OAR without any compromise is the main goal in using multichannel vaginal applicator in HDR brachytherapy. Conclusion: Multichannel plans were optimized using anatomical based inverse optimization algorithm of inverse planning simulation annealing. The optimization solution of the algorithm was to improve the clinical target volume dose coverage while reducing the dose to critical organs such as bladder, rectum and bowels. The comparison between SCP and MCP demonstrated MCP is superior to SCP where the dwell positions were based on geometric array only. It concluded that MCP is preferable and is able to provide certain features superior to SCP.

  1. Structural versus dynamical origins of mean-field behavior in a self-organized critical model of neuronal avalanches.

    PubMed

    Moosavi, S Amin; Montakhab, Afshin

    2015-11-01

    Critical dynamics of cortical neurons have been intensively studied over the past decade. Neuronal avalanches provide the main experimental as well as theoretical tools to consider criticality in such systems. Experimental studies show that critical neuronal avalanches show mean-field behavior. There are structural as well as recently proposed [Phys. Rev. E 89, 052139 (2014)] dynamical mechanisms that can lead to mean-field behavior. In this work we consider a simple model of neuronal dynamics based on threshold self-organized critical models with synaptic noise. We investigate the role of high-average connectivity, random long-range connections, as well as synaptic noise in achieving mean-field behavior. We employ finite-size scaling in order to extract critical exponents with good accuracy. We conclude that relevant structural mechanisms responsible for mean-field behavior cannot be justified in realistic models of the cortex. However, strong dynamical noise, which can have realistic justifications, always leads to mean-field behavior regardless of the underlying structure. Our work provides a different (dynamical) origin than the conventionally accepted (structural) mechanisms for mean-field behavior in neuronal avalanches. PMID:26651741

  2. Structural versus dynamical origins of mean-field behavior in a self-organized critical model of neuronal avalanches

    NASA Astrophysics Data System (ADS)

    Moosavi, S. Amin; Montakhab, Afshin

    2015-11-01

    Critical dynamics of cortical neurons have been intensively studied over the past decade. Neuronal avalanches provide the main experimental as well as theoretical tools to consider criticality in such systems. Experimental studies show that critical neuronal avalanches show mean-field behavior. There are structural as well as recently proposed [Phys. Rev. E 89, 052139 (2014), 10.1103/PhysRevE.89.052139] dynamical mechanisms that can lead to mean-field behavior. In this work we consider a simple model of neuronal dynamics based on threshold self-organized critical models with synaptic noise. We investigate the role of high-average connectivity, random long-range connections, as well as synaptic noise in achieving mean-field behavior. We employ finite-size scaling in order to extract critical exponents with good accuracy. We conclude that relevant structural mechanisms responsible for mean-field behavior cannot be justified in realistic models of the cortex. However, strong dynamical noise, which can have realistic justifications, always leads to mean-field behavior regardless of the underlying structure. Our work provides a different (dynamical) origin than the conventionally accepted (structural) mechanisms for mean-field behavior in neuronal avalanches.

  3. Aging Theories for Establishing Safe Life Spans of Airborne Critical Structural Components

    NASA Technical Reports Server (NTRS)

    Ko, William L.

    2003-01-01

    New aging theories have been developed to establish the safe life span of airborne critical structural components such as B-52B aircraft pylon hooks for carrying air-launch drop-test vehicles. The new aging theories use the equivalent-constant-amplitude loading spectrum to represent the actual random loading spectrum with the same damaging effect. The crack growth due to random loading cycling of the first flight is calculated using the half-cycle theory, and then extrapolated to all the crack growths of the subsequent flights. The predictions of the new aging theories (finite difference aging theory and closed-form aging theory) are compared with the classical flight-test life theory and the previously developed Ko first- and Ko second-order aging theories. The new aging theories predict the number of safe flights as considerably lower than that predicted by the classical aging theory, and slightly lower than those predicted by the Ko first- and Ko second-order aging theories due to the inclusion of all the higher order terms.

  4. Criticism in the Self, Brain, Relationships, and Social Structure: Implications for Psychodynamic Psychiatry.

    PubMed

    Shahar, Golan

    2016-01-01

    An integrative-psychodynamic theory of criticism in self and relationships is presented (Shahar, 2015). My theoretical starting point is the tension between Authenticity (A; our inherited potential, tantamount to Winnicott's True Self) and Self-Knowledge (SK; what we [think] we know about ourselves). Self-criticism, a formidable dimension of vulnerability to a wide array of psychopathologies, is construed as a distorted form of self-knowledge, reducing internal confusion at the expense of widening the gap between A and SK. Amalgamated by a genetic and neuroanatomic makeup, criticism of the self quickly translates into criticism-based interpersonal exchanges across the life span, culminating in an Axis of Criticism (ACRIM). A psychodynamic-integrative psychotherapy of malignant criticism in self and relationships is described. The article is concluded with some broad reflections on the implication of this work to the theory development and therapeutic action. PMID:27603804

  5. Investigating Predictive Role of Critical Thinking on Metacognition with Structural Equation Modeling

    ERIC Educational Resources Information Center

    Arslan, Serhat

    2015-01-01

    The purpose of this study is to examine the relationships between critical thinking and metacognition. The sample of study consists of 390 university students who were enrolled in different programs at Sakarya University, in Turkey. In this study, the Critical Thinking Disposition Scale and Metacognitive Thinking Scale were used. The relationships…

  6. Microhabitat Types Promote the Genetic Structure of a Micro-Endemic and Critically Endangered Mole Salamander (Ambystoma leorae) of Central Mexico

    PubMed Central

    Sunny, Armando; Monroy-Vilchis, Octavio; Reyna-Valencia, Carlos; Zarco-González, Martha M.

    2014-01-01

    The reduced immigration and emigration rates resulting from the lack of landscape connectivity of patches and the hospitality of the intervening matrix could favor the loss of alleles through genetic drift and an increased chance of inbreeding. In order for isolated populations to maintain sufficient levels of genetic diversity and adapt to environmental changes, one important conservation goal must be to preserve or reestablish connectivity among patches in a fragmented landscape. We studied the last known population of Ambystoma leorae, an endemic and critically threatened species. The aims of this study were: (1) to assess the demographic parameters of A. leorae and to distinguish and characterize the microhabitats in the river, (2) to determine the number of existing genetic groups or demes of A. leorae and to describe possible relationships between microhabitats types and demes, (3) to determine gene flow between demes, and (4) to search for geographic locations of genetic discontinuities that limit gene flow between demes. We found three types of microhabitats and three genetically differentiated subpopulations with a significant level of genetic structure. In addition, we found slight genetic barriers. Our results suggest that mole salamander’s species are very sensitive to microhabitat features and relatively narrow obstacles in their path. The estimates of bidirectional gene flow are consistent with the pattern of a stepping stone model between demes, where migration occurs between adjacent demes, but there is low gene flow between distant demes. We can also conclude that there is a positive correlation between microhabitats and genetic structure in this population. PMID:25076052

  7. Structure and Agency in Learning: A Critical Realist Theory of the Development of Capacity to Reflect on Academic Practice

    ERIC Educational Resources Information Center

    Kahn, Peter; Qualter, Anne; Young, Richard

    2012-01-01

    Theories of learning typically downplay the interplay between social structure and student agency. In this article, we adapt a causal hypothesis from realist social theory and draw on wider perspectives from critical realism to account for the development of capacity to engage in reflection on professional practice in academic roles. We thereby…

  8. Facilitating Interactions through Structured Web-Based Bulletin Boards: A Quasi-Experimental Study on Promoting Learners' Critical Thinking Skills

    ERIC Educational Resources Information Center

    Yang, Ya-Ting C.; Newby, Timothy; Bill, Robert

    2008-01-01

    This experimental study investigated the effectiveness of structured Web-Based Bulletin Board (WBB) discussions in improving the critical thinking (CT) skills of learners involved in veterinary distance learning, as well as their attitudes toward learning via WBBs. The two dependent variables were learners' CT skills and their attitudes toward…

  9. Free surface liquid films of binary mixtures. Two-dimensional steady structures at off-critical compositions

    NASA Astrophysics Data System (ADS)

    Bribesh, Fathi A. M.; Madruga, Santiago

    2016-03-01

    We present steady non-linear solutions of films of confined polymer blends deposited on a solid substrate at off-critical concentrations with a free deformable surface. The solutions are obtained numerically using a variational form of the Cahn-Hilliard equation in the static limit, which allows for internal diffuse interfaces between the two components of the mixture. Existence of most of the branches of non-linear solutions at off-critical concentrations can be predicted from the knowledge of the branching points obtained with a linear stability analysis plus the non-linear solutions at critical concentrations. However, some families of solutions are found not to have correspondence at critical compositions. We take a value for surface tension that allows strong deformations at the sharp free upper surface. Varying the average composition and the length and thickness of the films we find a rich morphology of static films in the form of laterally structure films, layered films, droplets on the substrate, droplets at the free surface, and checkerboard structures. We show that laterally structured solutions are energetically favorable over homogeneous and other structured solutions within the whole spinodal region and even close to the absolute stability binodal boundary.

  10. Probing the caveolin-1 P132L mutant: Critical insights into its oligomeric behavior and structure

    PubMed Central

    Rieth, Monica D.; Lee, Jinwoo; Glover, Kerney Jebrell

    2012-01-01

    Caveolin-1 is the most important protein found in caveolae, which are cell surface invaginations of the plasma membrane that act as signaling platforms. A single point mutation in the transmembrane domain of caveolin-1 (proline 132 to leucine) has deleterious effects on caveolae formation in vivo, and has been implicated in various disease states, particularly aggressive breast cancers. Using a combination of gel filtration chromatography and analytical ultracentrifugation we found that a fully-functional construct of caveolin-1 (Cav162–178) was a monomer in dodecylphosphocholine micelles. In contrast, the P132L mutant of Cav162–178 was dimeric. To explore the dimerization of the P132L mutant further, various truncated constructs (Cav182–178, Cav196–178, Cav162–136, Cav182–136, Cav196–136) were prepared which revealed that oligomerization occurs in the transmembrane domain (residues 96–136) of caveolin-1. To characterize the mutant structurally, solution-state NMR experiments in lyso-myristoylphosphatidylglycerol were undertaken of the Cav196–136 P132L mutant. Chemical shift analysis revealed that compared to the wild type, helix 2 in the transmembrane domain was lengthened by four residues (wild type, residues 111 to 129; mutant, residues 111–133), which corresponds to an extra turn in helix 2 of the mutant. Lastly, point mutations at position 132 of Cav162–178 (P132A, P132I, P132V, P132G, P132W, P132F) revealed that no other hydrophobic amino acid can preserve the monomeric state of Cav162–178 which indicates that proline 132 is critical in supporting proper caveolin-1 behavior. PMID:22506673

  11. Petroleum basins of Sakhalin and adjacent shelf

    SciTech Connect

    Mavrinski, Y.; Koblov, E. )

    1993-09-01

    Sixty-seven oil and gas fields have been discovered on Sakhalin and the adjacent shelf but the distribution of fields is uneven in north Sakhalin, south Sakhalin, and the Tatar basins. The sedimentary cover is composed of sandy, clayey, and siliceous rocks, with volcanogenic and coal-bearing deposits of Upper Cretaceous, Paleogene, and Neogene 8-12 km thick. Marine clayey and siliceous oil source rocks are regionally developed in the section at different stratigraphic levels; the organic matter is of mixed type and the content varies from 0.5 to 1.5%. The upper Oligocene and middle-upper Miocene source rocks in the north Sakhalin basin are typical, and the organic carbon content ranges from 1 to 5%. The level of organic matter catagenesis and conversion into hydrocarbons is high because of the high differential geothermal gradient in the basins, 30-50[degrees]C per km. Porous sandstones in the Miocene form the reservoirs in all fields with the exception of Okruzhnoye, where the pay zone is a siliceous claystone. Growth-fault rollovers and anticlines form the main traps ranging in area from 5 to 300 km[sup 2], with amplitudes between 100 and 600 m. both stratigraphic and structural traps have been identified. Considerable volumes of reserves are associated with the Miocene deposits of north Sakhalin, which are characterized by an optimum combination of oil source rocks, focused migration paths, and thick sequences of reservoirs and cap rocks. Six large fields have been discovered in the past 15 yr. Oil and condensate reserves stand at over 300 million MT, and gas reserves are about 900 billion m[sup 3].

  12. On the time-course of adjacent and non-adjacent transposed-letter priming

    PubMed Central

    Ktori, Maria; Kingma, Brechtsje; Hannagan, Thomas; Holcomb, Phillip J.; Grainger, Jonathan

    2014-01-01

    We compared effects of adjacent (e.g., atricle-ARTICLE) and non-adjacent (e.g., actirle-ARTICLE) transposed-letter (TL) primes in an ERP study using the sandwich priming technique. TL priming was measured relative to the standard double-substitution condition. We found significantly stronger priming effects for adjacent transpositions than non-adjacent transpositions (with 2 intervening letters) in behavioral responses (lexical decision latencies), and the adjacent priming effects emerged earlier in the ERP signal, at around 200 ms post-target onset. Non-adjacent priming effects emerged about 50 ms later and were short-lived, being significant only in the 250-300 ms time-window. Adjacent transpositions on the other hand continued to produce priming in the N400 time-window (300-500 ms post-target onset). This qualitatively different pattern of priming effects for adjacent and non-adjacent transpositions is discussed in the light of different accounts of letter transposition effects, and the utility of drawing a distinction between positional flexibility and positional noise. PMID:25364497

  13. Application of percolation theory to microtomography of structured media: Percolation threshold, critical exponents, and upscaling

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Regenauer-Lieb, Klaus

    2011-01-01

    Percolation theory provides a tool for linking microstructure and macroscopic material properties. In this paper, percolation theory is applied to the analysis of microtomographic images for the purpose of deriving scaling laws for upscaling of properties. We have tested the acquisition of quantities such as percolation threshold, crossover length, fractal dimension, and critical exponent of correlation length from microtomography. By inflating or deflating the target phase and percolation analysis, we can get a critical model and an estimation of the percolation threshold. The crossover length is determined from the critical model by numerical simulation. The fractal dimension can be obtained either from the critical model or from the relative size distribution of clusters. Local probabilities of percolation are used to extract the critical exponent of the correlation length. For near-isotropic samples such as sandstone and bread, the approach works very well. For strongly anisotropic samples, such as highly deformed rock (mylonite) and a tree branch, the percolation threshold and fractal dimension can be assessed with accuracy. However, the uncertainty of the correlation length makes it difficult to accurately extract its critical exponents. Therefore, this aspect of percolation theory cannot be reliably used for upscaling properties of strongly anisotropic media. Other methods of upscaling have to be used for such media.

  14. Structure, process and annual intensive care unit mortality across 69 centers: United States Critical Illness and Injury Trials Group Critical Illness Outcomes Study (USCIITG-CIOS)

    PubMed Central

    Checkley, William; Martin, Greg S; Brown, Samuel M; Chang, Steven Y; Dabbagh, Ousama; Fremont, Richard D; Girard, Timothy D; Rice, Todd W; Howell, Michael D; Johnson, Steven B; O'Brien, James; Park, Pauline K; Pastores, Stephen M; Patil, Namrata T; Pietropaoli, Anthony P; Putman, Maryann; Rotello, Leo; Siner, Jonathan; Sajid, Sahul; Murphy, David J; Sevransky, Jonathan E

    2014-01-01

    Objective Hospital-level variations in structure and process may affect clinical outcomes in intensive care units (ICUs). We sought to characterize the organizational structure, processes of care, use of protocols and standardized outcomes in a large sample of U.S. ICUs. Design We surveyed 69 ICUs about organization, size, volume, staffing, processes of care, use of protocols, and annual ICU mortality. Setting ICUs participating in the United States Critical Illness and Injury Trials Group Critical Illness Outcomes Study (USCIITG-CIOS). Measurements and Main Results We characterized structure and process variables across ICUs, investigated relationships between these variables and annual ICU mortality, and adjusted for illness severity using APACHE II. Ninety-four ICU directors were invited to participate in the study and 69 ICUs (73%) were enrolled, of which 25 (36%) were medical, 24 were surgical (35%) and 20 (29%) were of mixed type, and 64 (93%) were located in teaching hospitals with a median number of 5 trainees per ICU. Average annual ICU mortality was 10.8%, average APACHE II score was 19.3, 58% were closed units and 41% had a 24-hour in-house intensivist. In multivariable linear regression adjusted for APACHE II and multiple ICU structure and process factors, annual ICU mortality was lower in surgical ICUs than in medical ICUs (5.6% lower, 95% CI 2.4%–8.8%) or mixed ICUs (4.5% lower, 95% CI 0.4%–8.7%). We also found a lower annual ICU mortality among ICUs that had a daily plan of care review (5.8% lower, 95% CI 1.6%–10.0%) and a lower bed-to-nurse ratio (1.8% lower when the ratio decreased from 2:1 to 1.5:1; 95% CI 0.25%–3.4%). In contrast, 24-hour intensivist coverage (p=0.89) and closed ICU status (p=0.16) were not associated with a lower annual ICU mortality. Conclusions In a sample of 69 ICUs, a daily plan of care review and a lower bed-to-nurse ratio were both associated with a lower annual ICU mortality. In contrast to 24-hour intensivist

  15. Evolving Relationship Structures in Multi-sourcing Arrangements: The Case of Mission Critical Outsourcing

    NASA Astrophysics Data System (ADS)

    Heitlager, Ilja; Helms, Remko; Brinkkemper, Sjaak

    Information Technology Outsourcing practice and research mainly considers the outsourcing phenomenon as a generic fulfilment of the IT function by external parties. Inspired by the logic of commodity, core competencies and economies of scale; assets, existing departments and IT functions are transferred to external parties. Although the generic approach might work for desktop outsourcing, where standardisation is the dominant factor, it does not work for the management of mission critical applications. Managing mission critical applications requires a different approach where building relationships is critical. The relationships involve inter and intra organisational parties in a multi-sourcing arrangement, called an IT service chain, consisting of multiple (specialist) parties that have to collaborate closely to deliver high quality services.

  16. The influence of structural defects on intragranular critical currents of bulk MgB[sub 2].

    SciTech Connect

    Serquis, A.; Liao, Xiaozhou; Civale, L.; Zhu, Y. T.; Coulter, J. Y.; Peterson, D. E.; Mueller, F. M.

    2002-01-01

    Bulk MgB2 samples were prepared under different synthesis conditions and analyzed by scanning and transmission electron microscopy. The critical current densities were determined from the magnetization versus magnetic field curves of bulk and powder-dispersed-in-epoxy samples. Results show that through a slow cooling process, the oxygen dissolved in bulk MgB2 at high synthesis temperatures can segregate and form nanometer-sized coherent precipitates of Mg(B,O)2 in the MgB2 matrix. Magnetization measurements indicate that these precipitates act as effective flux pinning centers and therefore significantly improve the intra-grain critical current density and its field dependence.

  17. SOLIDS TRANSPORT BETWEEN ADJACENT CAFB FLUIDIZED BEDS

    EPA Science Inventory

    The report gives results of an experimental investigation of a pulsed, dense-phase pneumatic transport system for controlled circulation between adjacent fluidized beds. A model was developed to predict performance. The program provides technical support for EPA's program to demo...

  18. Border separation for adjacent orthogonal fields

    SciTech Connect

    Werner, B.L.; Khan, F.M.; Sharma, S.C.; Lee, C.K.; Kim, T.H. )

    1991-06-01

    Field border separations for adjacent orthogonal fields can be calculated geometrically, given the validity of some important assumptions such as beam alignment and field uniformity. Thermoluminescent dosimetry (TLD) measurements were used to investigate dose uniformity across field junctions as a function of field separation and, in particular, to review the CCSG recommendation for the treatment of medulloblastoma with separate head and spine fields.

  19. Structural and Critical Behaviors of Ag Rough Films Deposited on Liquid Substrates

    NASA Astrophysics Data System (ADS)

    Ye, Gao-xiang; Feng, Chun-mu; Zhang, Qi-rui; Ge, Hong-liang; Zhang, Xuan-jia

    1996-10-01

    A new Ag rough film system, deposited on silicone oil surfaces by rf-magnetron sputtering method, has been fabricated. The chrysanthemum-like surface morphology at micron length scale is observed. It is proposed that the anomalous critical behavior mainly results from the relative shift between the Ag atom clusters and the substrate. The discussion of the deposition mechanism is also presented.

  20. The Limits of Critical Pedagogy: Teaching about Structural Obstacles to Students who Overcame Them

    ERIC Educational Resources Information Center

    Luykx, Aurolyn; Heyman, Josiah

    2013-01-01

    This article focuses on efforts to critically analyze the social reproductive functions of schooling with a group of pre-service teachers in the US-Mexico border region, and on students' reactions to these efforts. The students--all female, predominantly Mexican-American--had experienced both educational discrimination and academic success,…

  1. Effect of obesity on the pharmacokinetics of antimicrobials in critically ill patients: A structured review.

    PubMed

    Alobaid, Abdulaziz S; Hites, Maya; Lipman, Jeffrey; Taccone, Fabio Silvio; Roberts, Jason A

    2016-04-01

    The increased prevalence of obesity presents challenges for clinicians aiming to provide optimised antimicrobial dosing in the intensive care unit. Obesity is likely to exacerbate the alterations to antimicrobial pharmacokinetics when the chronic diseases associated with obesity exist with the acute pathophysiological changes associated with critical illness. The purpose of this paper is to review the potential pharmacokinetic (PK) changes of antimicrobials in obese critically ill patients and the implications for appropriate dosing. We found that hydrophilic antimicrobials (e.g. β-lactams, vancomycin, daptomycin) were more likely to manifest altered pharmacokinetics in critically ill patients who are obese. In particular for β-lactam antibiotics, obesity is associated with a larger volume of distribution (Vd). In obese critically ill patients, piperacillin is also associated with a lower drug clearance (CL). For doripenem, these PK changes have been associated with reduced achievement of pharmacodynamic (PD) targets when standard drug doses are used. For vancomycin, increases in Vd are associated with increasing total body weight (TBW), meaning that the loading dose should be based on TBW even in obese patients. For daptomycin, an increased Vd is not considered to be clinically relevant. For antifungals, little data exist in obese critically ill patients; during fluconazole therapy, an obese patient had a lower Vd and higher CL than non-obese comparators. Overall, most studies suggested that standard dosage regimens of most commonly used antimicrobials are sufficient to achieve PD targets. However, it is likely that larger doses would be required for pathogens with higher minimum inhibitory concentrations. PMID:26988339

  2. A critical survey of vestigial structures in the postcranial skeletons of extant mammals

    PubMed Central

    Moch, John G.

    2015-01-01

    In the Mammalia, vestigial skeletal structures abound but have not previously been the focus of study, with a few exceptions (e.g., whale pelves). Here we use a phylogenetic bracketing approach to identify vestigial structures in mammalian postcranial skeletons and present a descriptive survey of such structures in the Mammalia. We also correct previous misidentifications, including the previous misidentification of vestigial caviid metatarsals as sesamoids. We also examine the phylogenetic distribution of vestigiality and loss. This distribution indicates multiple vestigialization and loss events in mammalian skeletal structures, especially in the hand and foot, and reveals no correlation in such events between mammalian fore and hind limbs. PMID:26623192

  3. The Hidden Rule: A Critical Discussion of Harvard University's Governing Structure. [A Harvard Watch Report].

    ERIC Educational Resources Information Center

    Weissman, Robert

    The governing structure of Harvard University is reviewed, and the findings include the following: (1) Harvard's present administrative and governance structure utilize corporate techniques of management that allow the president to diffuse administrative tasks without diffusing power--the difficulty of locating responsibility in the decentralized…

  4. Adjacent Segment Pathology after Lumbar Spinal Fusion.

    PubMed

    Lee, Jae Chul; Choi, Sung-Woo

    2015-10-01

    One of the major clinical issues encountered after lumbar spinal fusion is the development of adjacent segment pathology (ASP) caused by increased mechanical stress at adjacent segments, and resulting in various radiographic changes and clinical symptoms. This condition may require surgical intervention. The incidence of ASP varies with both the definition and methodology adopted in individual studies; various risk factors for this condition have been identified, although a significant controversy still exists regarding their significance. Motion-preserving devices have been developed, and some studies have shown their efficacy of preventing ASP. Surgeons should be aware of the risk factors of ASP when planning a surgery, and accordingly counsel their patients preoperatively. PMID:26435804

  5. The Crystal Structure of Nitrosomonas europaea Sucrose Synthase Reveals Critical Conformational Changes and Insights into Sucrose Metabolism in Prokaryotes

    PubMed Central

    Wu, Rui; Asención Diez, Matías D.; Figueroa, Carlos M.; Machtey, Matías; Iglesias, Alberto A.; Ballicora, Miguel A.

    2015-01-01

    ABSTRACT In this paper we report the first crystal structure of a prokaryotic sucrose synthase from the nonphotosynthetic bacterium Nitrosomonas europaea. The obtained structure was in an open form, whereas the only other available structure, from the plant Arabidopsis thaliana, was in a closed conformation. Comparative structural analysis revealed a “hinge-latch” combination, which is critical to transition between the open and closed forms of the enzyme. The N. europaea sucrose synthase shares the same fold as the GT-B family of the retaining glycosyltransferases. In addition, a triad of conserved homologous catalytic residues in the family was shown to be functionally critical in the N. europaea sucrose synthase (Arg567, Lys572, and Glu663). This implies that sucrose synthase shares not only a common origin with the GT-B family but also a similar catalytic mechanism. The enzyme preferred transferring glucose from ADP-glucose rather than UDP-glucose like the eukaryotic counterparts. This predicts that these prokaryotic organisms have a different sucrose metabolic scenario from plants. Nucleotide preference determines where the glucose moiety is targeted after sucrose is degraded. IMPORTANCE We obtained biochemical and structural evidence of sucrose metabolism in nonphotosynthetic bacteria. Until now, only sucrose synthases from photosynthetic organisms have been characterized. Here, we provide the crystal structure of the sucrose synthase from the chemolithoautotroph N. europaea. The structure supported that the enzyme functions with an open/close induced fit mechanism. The enzyme prefers as the substrate adenine-based nucleotides rather than uridine-based like the eukaryotic counterparts, implying a strong connection between sucrose and glycogen metabolism in these bacteria. Mutagenesis data showed that the catalytic mechanism must be conserved not only in sucrose synthases but also in all other retaining GT-B glycosyltransferases. PMID:26013491

  6. Atomic structure of recombinant thaumatin II reveals flexible conformations in two residues critical for sweetness and three consecutive glycine residues.

    PubMed

    Masuda, Tetsuya; Mikami, Bunzo; Tani, Fumito

    2014-11-01

    Thaumatin, an intensely sweet-tasting protein used as a sweetener, elicits a sweet taste at 50 nM. Although two major variants designated thaumatin I and thaumatin II exist in plants, there have been few dedicated thaumatin II structural studies and, to date, data beyond atomic resolution had not been obtained. To identify the detailed structural properties explaining why thaumatin elicits a sweet taste, the structure of recombinant thaumatin II was determined at the resolution of 0.99 Å. Atomic resolution structural analysis with riding hydrogen atoms illustrated the differences in the direction of the side-chains more precisely and the electron density maps of the C-terminal regions were markedly improved. Though it had been suggested that the three consecutive glycine residues (G142-G143-G144) have highly flexible conformations, G143, the central glycine residue was successfully modelled in two conformations for the first time. Furthermore, the side chain r.m.s.d. values for two residues (R67 and R82) critical for sweetness exhibited substantially higher values, suggesting that these residues are highly disordered. These results demonstrated that the flexible conformations in two critical residues favoring their interaction with sweet taste receptors are prominent features of the intensely sweet taste of thaumatin. PMID:25066915

  7. Analytic study of chaos of the tent map: Band structures, power spectra, and critical behaviors

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Mori, H.; Shigematsu, H.

    1983-05-01

    Chaotic behaviors of the tent map (a piecewise-linear, continuous map with a unique maximum) are studied analytically throughout its chaotic region in terms of the invariant density and the power spectrum. As the height of the maximum is lowered, successive band-splitting transitions occur in the chaotic region and accumulate to the transition point into the nonchaotic region. The timecorrelation function of nonperiodic orbits and their power spectrum are calculated exactly at the band-splitting points and in the vicinity of these points. The method of eigenvalue problems of the Frobenius-Perron operator is used. 2 m-1 critical modes, where m = 1,2, 3, ..., are found which exhibit the critical slowing-down near the 2 m-1-band to 2 m -band transition point. After the transition these modes become periodic modes which represent the cycling of nonperiodic orbits among 2 m bands together with the periodic modes generated by the preceding band splittings. Scaling laws near the transition point into the nonchaotic region are investigated and a new scaling law is found for the total intensity of the periodic part of the spectrum.

  8. The Catalytic Copper of Peptidylglycine alpha-Hydroxylating Monooxygenase also Plays a Critical Structural Role

    SciTech Connect

    Siebert,X.; Eipper, B.; Mains, R.; Prigge, S.; Blackburn, N.; Amzel, L.

    2005-01-01

    Many bioactive peptides require amidation of their carboxy terminus to exhibit full biological activity. Peptidylglycine alpha-Hydroxylating Monooxygenase (PHM; EC 1.14.17.3), the enzyme that catalyzes the first of the two steps of this reaction, is composed of two domains, each of which binds one copper atom (CuH and CuM). The CuM site includes Met314 and two His residues as ligands. Mutation of Met314 to Ile inactivates PHM, but has only a minimal effect on the EXAFS spectrum of the oxidized enzyme, implying that it contributes only marginally to stabilization of the CuM site. To characterize the role of Met314 as a CuM ligand, we determined the structure of the M314I-PHM mutant. Since the mutant protein failed to crystallize in the conditions of the original wild-type protein, this structure determination required finding a new crystal form. The M314I-PHM mutant structure confirms that the mutation does not abolish CuM binding to the enzyme, but causes other structural perturbations that affect the overall stability of the enzyme and the integrity of the CuH site. To eliminate possible effects of crystal contacts, we redetermined the structure of wt-PHM in the M314I-PHM crystal form and showed that it does not differ from the structure of wt-PHM in the original crystals. M314I-PHM was also shown to be less stable than wt-PHM by Differential Scanning Calorimetry (DSC). Both structural and calorimetric studies point to a structural role for the CuM site, in addition to its established catalytic role.

  9. Secondary Structure Transition and Critical Stress for a Model of Spider Silk Assembly.

    PubMed

    Giesa, Tristan; Perry, Carole C; Buehler, Markus J

    2016-02-01

    Spiders spin their silk from an aqueous solution to a solid fiber in ambient conditions. However, to date, the assembly mechanism in the spider silk gland has not been satisfactorily explained. In this paper, we use molecular dynamics simulations to model Nephila clavipes MaSp1 dragline silk formation under shear flow and determine the secondary structure transitions leading to the experimentally observed fiber structures. While no experiments are performed on the silk fiber itself, insights from this polypeptide model can be transferred to the fiber scale. The novelty of this study lies in the calculation of the shear stress (300-700 MPa) required for fiber formation and identification of the amino acid residues involved in the transition. This is the first time that the shear stress has been quantified in connection with a secondary structure transition. By study of molecules containing varying numbers of contiguous MaSp1 repeats, we determine that the smallest molecule size giving rise to a "silk-like" structure contains six polyalanine repeats. Through a probability analysis of the secondary structure, we identify specific amino acids that transition from α-helix to β-sheet. In addition to portions of the polyalanine section, these amino acids include glycine, leucine, and glutamine. The stability of β-sheet structures appears to arise from a close proximity in space of helices in the initial spidroin state. Our results are in agreement with the forces exerted by spiders in the silking process and the experimentally determined global secondary structure of spidroin and pulled MaSp1 silk. Our study emphasizes the role of shear in the assembly process of silk and can guide the design of microfluidic devices that attempt to mimic the natural spinning process and predict molecular requirements for the next generation of silk-based functional materials. PMID:26669270

  10. Off-Policy Actor-Critic Structure for Optimal Control of Unknown Systems With Disturbances.

    PubMed

    Song, Ruizhuo; Lewis, Frank L; Wei, Qinglai; Zhang, Huaguang

    2016-05-01

    An optimal control method is developed for unknown continuous-time systems with unknown disturbances in this paper. The integral reinforcement learning (IRL) algorithm is presented to obtain the iterative control. Off-policy learning is used to allow the dynamics to be completely unknown. Neural networks are used to construct critic and action networks. It is shown that if there are unknown disturbances, off-policy IRL may not converge or may be biased. For reducing the influence of unknown disturbances, a disturbances compensation controller is added. It is proven that the weight errors are uniformly ultimately bounded based on Lyapunov techniques. Convergence of the Hamiltonian function is also proven. The simulation study demonstrates the effectiveness of the proposed optimal control method for unknown systems with disturbances. PMID:25935054

  11. Evaluation of Pactruss design characteristics critical to space station primary structure

    NASA Technical Reports Server (NTRS)

    Hedgepeth, John M.

    1987-01-01

    Several aspects of the possible application of the Pactruss concept to the primary truss structure of the space station are investigated. Estimates are made of the loads and hinge moments in deploying diagonal members as full deployment is approached. Included are the effects of beam columning and compliance of the surrounding structure. Requirements for joint design are suggested and a two-stage mid-diagonal latching hinge concept is described or analyzed. The problems with providing the experimental and theoretical tools needed for assuring reliable synchronous deployment are discussed and a first attempt at high-fidelity analytical simulation with NASTRAN is described. An alternative construction scenario in which the entire dual-keel truss structure is deployed as a single Shuttle payload is suggested.

  12. Lying to ourselves: rationality, critical reflexivity, and the moral order as 'structured agency'.

    PubMed

    Goodman, Benny

    2016-07-01

    A report suggests that United States' army officers may engage in dishonest reporting regarding their compliance procedures. Similarly, nurses with espoused high ethical standards sometimes fail to live up to them and may do so while deceiving themselves about such practices. Reasons for lapses are complex. However, multitudinous managerial demands arising within 'technical and instrumental rationality' may impact on honest decision-making. This paper suggests that compliance processes, which operates within the social structural context of the technical and instrumental rationality manifest as 'managerialism', contributes to professional 'dishonesty' about lapses in care, sometimes through 'thoughtlessness'. The need to manage risk, measure, account, and control in order to deliver efficiency, effectiveness, and economy (technical rationality) thus has both unintended and dysfunctional consequences. Meeting compliance requirements may be mediated by factors such as the 'affect heuristic' and 'reflexive deliberations' as part of the 'structured agency' of nurses. It is the complexity of 'structured agency' which may explain why some nurses fail to respond to such things as sentinel events, a failure to recognize 'personal troubles' as 'public issues', a failure which to outsiders who expect rational and professional responses may seem inconceivable. There is a need to understand these processes so that nurses can critique the context in which they work and to move beyond either/or explanations of structure or agency for care failures, and professional dishonesty. PMID:27197710

  13. Marked population structure and recent migration in the critically endangered Sumatran orangutan (Pongo abelii).

    PubMed

    Nater, Alexander; Arora, Natasha; Greminger, Maja P; van Schaik, Carel P; Singleton, Ian; Wich, Serge A; Fredriksson, Gabriella; Perwitasari-Farajallah, Dyah; Pamungkas, Joko; Krützen, Michael

    2013-01-01

    A multitude of factors influence how natural populations are genetically structured, including dispersal barriers, inhomogeneous habitats, and social organization. Such population subdivision is of special concern in endangered species, as it may lead to reduced adaptive potential and inbreeding in local subpopulations, thus increasing the risk of future extinctions. With only 6600 animals left in the wild, Sumatran orangutans (Pongo abelii) are among the most endangered, but also most enigmatic, great ape species. In order to infer the fine-scale population structure and connectivity of Sumatran orangutans, we analyzed the most comprehensive set of samples to date, including mitochondrial hyper-variable region I haplotypes for 123 individuals and genotypes of 27 autosomal microsatellite markers for 109 individuals. For both mitochondrial and autosomal markers, we found a pronounced population structure, caused by major rivers, mountain ridges, and the Toba caldera. We found that genetic diversity and corresponding long-term effective population size estimates vary strongly among sampling regions for mitochondrial DNA, but show remarkable similarity for autosomal markers, hinting at male-driven long-distance gene flow. In support of this, we identified several individuals that were most likely sired by males originating from other genetic clusters. Our results highlight the effect of natural barriers in shaping the genetic structure of great ape populations, but also point toward important dispersal corridors on northern Sumatra that allow for genetic exchange. PMID:23077232

  14. The design process for a pumpkin balloon: structural synthesis, structural analysis, and analytical assessment of some critical design issues

    NASA Astrophysics Data System (ADS)

    Schur, W. W.

    Effects of varying parameters in the design of super-pressure balloons of the "pumpkin" shape such as gore design, tendon stiffness, and structural lack-of-fit between tendons and gore seams are exhibited in analytical studies. The importance of an accurate representation of Poisson's effect for the film is demonstrated. Important design aspects that affect load paths and robustness of the design are discussed together with their resolution and quantification where applicable.

  15. Adjuvant formulation structure and composition are critical for the development of an effective vaccine against tuberculosis.

    PubMed

    Orr, Mark T; Fox, Christopher B; Baldwin, Susan L; Sivananthan, Sandra J; Lucas, Elyse; Lin, Susan; Phan, Tony; Moon, James J; Vedvick, Thomas S; Reed, Steven G; Coler, Rhea N

    2013-11-28

    One third of the world is infected with Mycobacterium tuberculosis (Mtb) with eight million new cases of active tuberculosis (TB) each year. Development of a new vaccine to augment or replace the only approved TB vaccine, BCG, is needed to control this disease. Mtb infection is primarily controlled by TH1 cells through the production of IFN-γ and TNF which activate infected macrophages to kill the bacterium. Here we examine an array of adjuvant formulations containing the TLR4 agonist GLA to identify candidate adjuvants to pair with ID93, a lead TB vaccine antigen, to elicit protective TH1 responses. We evaluate a variety of adjuvant formulations including alum, liposomes, and oil-in-water emulsions to determine how changes in formulation composition alter adjuvant activity. We find that alum and an aqueous nanosuspension of GLA synergize to enhance generation of ID93-specific TH1 responses, whereas neither on their own are effective adjuvants for generation of ID93-specific TH1 responses. For GLA containing oil-in-water emulsions, the selection of the oil component is critical for adjuvant activity, whereas a variety of lipid components may be used in liposomal formulations of GLA. The composition of the liposome formulation of ID93/GLA does alter the magnitude of the TH1 response. These results demonstrate that there are multiple solutions for an effective formulation of a novel TB vaccine candidate that enhances both TH1 generation and protective efficacy. PMID:23933525

  16. Critical tipping point distinguishing two types of transitions in modular network structures.

    PubMed

    Shai, Saray; Kenett, Dror Y; Kenett, Yoed N; Faust, Miriam; Dobson, Simon; Havlin, Shlomo

    2015-12-01

    Modularity is a key organizing principle in real-world large-scale complex networks. The relatively sparse interactions between modules are critical to the functionality of the system and are often the first to fail. We model such failures as site percolation targeting interconnected nodes, those connecting between modules. We find, using percolation theory and simulations, that they lead to a "tipping point" between two distinct regimes. In one regime, removal of interconnected nodes fragments the modules internally and causes the system to collapse. In contrast, in the other regime, while only attacking a small fraction of nodes, the modules remain but become disconnected, breaking the entire system. We show that networks with broader degree distribution might be highly vulnerable to such attacks since only few nodes are needed to interconnect the modules, consequently putting the entire system at high risk. Our model has the potential to shed light on many real-world phenomena, and we briefly consider its implications on recent advances in the understanding of several neurocognitive processes and diseases. PMID:26764742

  17. Critical tipping point distinguishing two types of transitions in modular network structures

    NASA Astrophysics Data System (ADS)

    Shai, Saray; Kenett, Dror Y.; Kenett, Yoed N.; Faust, Miriam; Dobson, Simon; Havlin, Shlomo

    2015-12-01

    Modularity is a key organizing principle in real-world large-scale complex networks. The relatively sparse interactions between modules are critical to the functionality of the system and are often the first to fail. We model such failures as site percolation targeting interconnected nodes, those connecting between modules. We find, using percolation theory and simulations, that they lead to a "tipping point" between two distinct regimes. In one regime, removal of interconnected nodes fragments the modules internally and causes the system to collapse. In contrast, in the other regime, while only attacking a small fraction of nodes, the modules remain but become disconnected, breaking the entire system. We show that networks with broader degree distribution might be highly vulnerable to such attacks since only few nodes are needed to interconnect the modules, consequently putting the entire system at high risk. Our model has the potential to shed light on many real-world phenomena, and we briefly consider its implications on recent advances in the understanding of several neurocognitive processes and diseases.

  18. Mitochondrial structure and dynamics as critical factors in honey bee (Apis mellifera L.) caste development.

    PubMed

    Santos, Douglas Elias; Alberici, Luciane Carla; Hartfelder, Klaus

    2016-06-01

    The relationship between nutrition and phenotype is an especially challenging question in cases of facultative polyphenism, like the castes of social insects. In the honey bee, Apis mellifera, unexpected modifications in conserved signaling pathways revealed the hypoxia response as a possible mechanism underlying the regulation of body size and organ growth. Hence, the current study was designed to investigate possible causes of why the three hypoxia core genes are overexpressed in worker larvae. Parting from the hypothesis that this has an endogenous cause and is not due to differences in external oxygen levels we investigated mitochondrial numbers and distribution, as well as mitochondrial oxygen consumption rates in fat body cells of queen and worker larvae during the caste fate-critical larval stages. By immunofluorescence and electron microscopy we found higher densities of mitochondria in queen larval fat body, a finding further confirmed by a citrate synthase assay quantifying mitochondrial functional units. Oxygen consumption measurements by high-resolution respirometry revealed that queen larvae have higher maximum capacities of ATP production at lower physiological demand. Finally, the expression analysis of mitogenesis-related factors showed that the honey bee TFB1 and TFB2 homologs, and a nutritional regulator, ERR, are overexpressed in queen larvae. These results are strong evidence that the differential nutrition of queen and worker larvae by nurse bees affects mitochondrial dynamics and functionality in the fat body of these larvae, hence explaining their differential hypoxia response. PMID:27058771

  19. Critical density solitary waves structures in a hot magnetized dusty plasma with vortexlike ion distribution in phase space

    SciTech Connect

    El-Labany, S.K.; El-Shamy, E.F.

    2005-04-15

    The nonlinear properties of solitary waves structures in a hot magnetized dusty plasma consisting of isothermal hot electrons, nonisothermal ions, and high negatively charged massive dust grains are reported. A modified Korteweg-de Vries (modified KdV) equation, which admits a solitary waves solution, for small but finite amplitude, is derived using a reductive perturbation theory. A nonisothermal ion distribution provides the possibility of existence of rarefactive solitary waves. On the other hand, the dynamics of solitary waves at a critical ion density is governed by KdV equation. The modification in the amplitude and width of the solitary waves structures due to the inclusion of obliqueness and external magnetic field are also investigated.

  20. Neristatin 1 provides critical insight into bryostatin 1 structure-function relationships.

    PubMed

    Kedei, Noemi; Kraft, Matthew B; Keck, Gary E; Herald, Cherry L; Melody, Noeleen; Pettit, George R; Blumberg, Peter M

    2015-04-24

    Bryostatin 1, a complex macrocyclic lactone isolated from Bugula neritina, has been the subject of multiple clinical trials for cancer. Although it functions as an activator of protein kinase C (PKC) in vitro, bryostatin 1 paradoxically antagonizes most responses to the prototypical PKC activator, the phorbol esters. The bottom half of the bryostatin 1 structure has been shown to be sufficient to confer binding to PKC. In contrast, we have previously shown that the top half of the bryostatin 1 structure is necessary for its unique biological behavior to antagonize phorbol ester responses. Neristatin 1 comprises a top half similar to that of bryostatin 1 together with a distinct bottom half that confers PKC binding. We report here that neristatin 1 is bryostatin 1-like, not phorbol ester-like, in its biological activity on U937 promyelocytic leukemia cells. We conclude that the top half of the bryostatin 1 structure is largely sufficient for bryostatin 1-like activity, provided the molecule also possesses an appropriate PKC binding domain. PMID:25808573

  1. Subscale and Full-Scale Testing of Buckling-Critical Launch Vehicle Shell Structures

    NASA Technical Reports Server (NTRS)

    Hilburger, Mark W.; Haynie, Waddy T.; Lovejoy, Andrew E.; Roberts, Michael G.; Norris, Jeffery P.; Waters, W. Allen; Herring, Helen M.

    2012-01-01

    New analysis-based shell buckling design factors (aka knockdown factors), along with associated design and analysis technologies, are being developed by NASA for the design of launch vehicle structures. Preliminary design studies indicate that implementation of these new knockdown factors can enable significant reductions in mass and mass-growth in these vehicles and can help mitigate some of NASA s launch vehicle development and performance risks by reducing the reliance on testing, providing high-fidelity estimates of structural performance, reliability, robustness, and enable increased payload capability. However, in order to validate any new analysis-based design data or methods, a series of carefully designed and executed structural tests are required at both the subscale and full-scale level. This paper describes recent buckling test efforts at NASA on two different orthogrid-stiffened metallic cylindrical shell test articles. One of the test articles was an 8-ft-diameter orthogrid-stiffened cylinder and was subjected to an axial compression load. The second test article was a 27.5-ft-diameter Space Shuttle External Tank-derived cylinder and was subjected to combined internal pressure and axial compression.

  2. Cellular and molecular mechanisms activating the cell death processes by chalcones: Critical structural effects.

    PubMed

    Champelovier, Pierre; Chauchet, Xavier; Hazane-Puch, Florence; Vergnaud, Sabrina; Garrel, Catherine; Laporte, François; Boutonnat, Jean; Boumendjel, Ahcène

    2013-12-01

    Chalcones are naturally occurring compounds with diverse pharmacological activities. Chalcones derive from the common structure: 1,3-diphenylpropenone. The present study aims to better understand the mechanistic pathways triggering chalcones anticancer effects and providing evidences that minor structural difference could lead to important difference in mechanistic effect. We selected two recently investigated chalcones (A and B) and investigated them on glioblastoma cell lines. It was found that chalcone A induced an apoptotic process (type I PCD), via the activation of caspase-3, -8 and -9. Chalcone A also increased CDK1/cyclin B ratios and decreased the mitochondrial transmembrane potential (ΔΨm). Chalcone B induced an autophagic cell death process (type II PCD), ROS-related but independent of both caspases and protein synthesis. Both chalcones increased Bax/Bcl2 ratios and decreased Ki67 and CD71 antigen expressions. The present investigation reveals that despite the close structure of chalcones A and B, significant differences in mechanism of effect were found. PMID:24134853

  3. Syngap1 haploinsufficiency damages a postnatal critical period of pyramidal cell structural maturation linked to cortical circuit assembly

    PubMed Central

    Aceti, Massimiliano; Creson, Thomas K.; Vaissiere, Thomas; Rojas, Camilo; Huang, Wen-Chin; Wang, Ya-Xian; Petralia, Ronald S.; Page, Damon T.; Miller, Courtney A.; Rumbaugh, Gavin

    2014-01-01

    Background Genetic haploinsufficiency of Syngap1 commonly occurs in developmental brain disorders, such as intellectual disability (ID), epilepsy, schizophrenia (SCZ), and autism spectrum (ASD) disorder. Thus, studying mouse models of Syngap1 haploinsufficiency may uncover pathological developmental processes common among distinct brain disorders. Methods A Syngap1 haploinsufficiency model was used to explore the relationship between critical period dendritic spine damage, cortical circuit assembly and the window for genetic rescue in order to understand how damaging mutations disrupt key substrates of mouse brain development. Results Syngap1 mutations broadly disrupted a developmentally sensitive period that corresponded to the period of heightened postnatal cortical synaptogenesis. Pathogenic Syngap1 mutations caused a coordinated acceleration of dendrite elongation and spine morphogenesis, and pruning of these structures in neonatal cortical pyramidal neurons. These mutations also prevented a form of developmental structural plasticity associated with experience-dependent reorganization of brain circuits. Consistent with these findings, Syngap1 mutant mice displayed an altered pattern of long-distance synaptic inputs into a cortical area important for cognition. Interestingly, the ability to genetically improve the behavioral endophenotype of Syngap1 mice decreased slowly over postnatal development and mapped onto the developmental period of coordinated dendritic insults. Conclusions Pathogenic Syngap1 mutations have a profound impact on the dynamics and structural integrity of pyramidal cell postsynaptic structures known to guide the de novo wiring of nascent cortical circuits. These findings support the idea that disrupted critical periods of dendritic growth and spine plasticity may be a common pathological process in developmental brain disorders. PMID:25444158

  4. Probabilistic Estimation of Critical Flaw Sizes in the Primary Structure Welds of the Ares I-X Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Pai, Shantaram S.; Hoge, Peter A.; Patel, B. M.; Nagpal, Vinod K.

    2009-01-01

    The primary structure of the Ares I-X Upper Stage Simulator (USS) launch vehicle is constructed of welded mild steel plates. There is some concern over the possibility of structural failure due to welding flaws. It was considered critical to quantify the impact of uncertainties in residual stress, material porosity, applied loads, and material and crack growth properties on the reliability of the welds during its pre-flight and flight. A criterion--an existing maximum size crack at the weld toe must be smaller than the maximum allowable flaw size--was established to estimate the reliability of the welds. A spectrum of maximum allowable flaw sizes was developed for different possible combinations of all of the above listed variables by performing probabilistic crack growth analyses using the ANSYS finite element analysis code in conjunction with the NASGRO crack growth code. Two alternative methods were used to account for residual stresses: (1) The mean residual stress was assumed to be 41 ksi and a limit was set on the net section flow stress during crack propagation. The critical flaw size was determined by parametrically increasing the initial flaw size and detecting if this limit was exceeded during four complete flight cycles, and (2) The mean residual stress was assumed to be 49.6 ksi (the parent material s yield strength) and the net section flow stress limit was ignored. The critical flaw size was determined by parametrically increasing the initial flaw size and detecting if catastrophic crack growth occurred during four complete flight cycles. Both surface-crack models and through-crack models were utilized to characterize cracks in the weld toe.

  5. A critical switch in the enzymatic properties of the Cid1 protein deciphered from its product-bound crystal structure

    PubMed Central

    Munoz-Tello, Paola; Gabus, Caroline; Thore, Stéphane

    2014-01-01

    The addition of uridine nucleotide by the poly(U) polymerase (PUP) enzymes has a demonstrated impact on various classes of RNAs such as microRNAs (miRNAs), histone-encoding RNAs and messenger RNAs. Cid1 protein is a member of the PUP family. We solved the crystal structure of Cid1 in complex with non-hydrolyzable UMPNPP and a short dinucleotide compound ApU. These structures revealed new residues involved in substrate/product stabilization. In particular, one of the three catalytic aspartate residues explains the RNA dependence of its PUP activity. Moreover, other residues such as residue N165 or the β-trapdoor are shown to be critical for Cid1 activity. We finally suggest that the length and sequence of Cid1 substrate RNA influence the balance between Cid1's processive and distributive activities. We propose that particular processes regulated by PUPs require the enzymes to switch between the two types of activity as shown for the miRNA biogenesis where PUPs can either promote DICER cleavage via short U-tail or trigger miRNA degradation by adding longer poly(U) tail. The enzymatic properties of these enzymes may be critical for determining their particular function in vivo. PMID:24322298

  6. White Oak Creek Embayment time-critical CERCLA removal action sediment-retention structure. Environmental Restoration Program

    SciTech Connect

    Not Available

    1992-09-01

    Over a 20-month period between September 1990 and April 1992, the Department of Energy (DOE), acting through Martin Marietta Energy Systems, Inc., managing contractor for the DOE Oak Ridge Field Office (DOE-OR), conducted a DOE-lead and DOE-funded time-critical removal action at the White Oak Creek Embayment (WOCE), pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The time-critical removal action specifically consisted of the design and construction of a sediment-retention structure across the mouth of WOCE to prevent off-site migration of sediments contaminated by cesium ({sup 137}Cs) into the Clinch River. Construction of a sediment-retention structure was completed in mid-April 1992. The purpose of this report is to meet the substantive requirements of 40 CFR 300.165 describing ``a complete report on the removal operation and the actions taken.`` This section of the NCP specifically addresses on-scene coordinator reports for the Environmental Protection Agency (EPA) Superfund-lead actions and includes several elements that are not applicable to this DOE-lead action. Only those sections that are pertinent and applicable are addressed in this final report.

  7. A critical switch in the enzymatic properties of the Cid1 protein deciphered from its product-bound crystal structure.

    PubMed

    Munoz-Tello, Paola; Gabus, Caroline; Thore, Stéphane

    2014-03-01

    The addition of uridine nucleotide by the poly(U) polymerase (PUP) enzymes has a demonstrated impact on various classes of RNAs such as microRNAs (miRNAs), histone-encoding RNAs and messenger RNAs. Cid1 protein is a member of the PUP family. We solved the crystal structure of Cid1 in complex with non-hydrolyzable UMPNPP and a short dinucleotide compound ApU. These structures revealed new residues involved in substrate/product stabilization. In particular, one of the three catalytic aspartate residues explains the RNA dependence of its PUP activity. Moreover, other residues such as residue N165 or the β-trapdoor are shown to be critical for Cid1 activity. We finally suggest that the length and sequence of Cid1 substrate RNA influence the balance between Cid1's processive and distributive activities. We propose that particular processes regulated by PUPs require the enzymes to switch between the two types of activity as shown for the miRNA biogenesis where PUPs can either promote DICER cleavage via short U-tail or trigger miRNA degradation by adding longer poly(U) tail. The enzymatic properties of these enzymes may be critical for determining their particular function in vivo. PMID:24322298

  8. Microprocessor controlled ultrahigh vacuum evaporations of critical thin films, multilayer structures, and coevaporated materials

    SciTech Connect

    Fischer, H.; Grob, M.; Peter, G.; Koprio, J.A.

    1988-05-01

    The use of a quadrupole mass spectrometer as a rate monitor is described for a fast and accurate deposition control down to very low evaporation rates in an ultrahigh vacuum plant. In several applications of this concept, a rate control down to 0.1 A/s in single-source and coevaporation experiments could be documented for different materials and material combinations. The feasibility of operation at oxygen gas pressures of up to 4.5 x 10/sup -5/ mbar is shown for yttrium/copper coevaporations. Multilayer structures were deposited under microprocessor control with the same rate control method used.

  9. Practical theories for service life prediction of critical aerospace structural components

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Monaghan, Richard C.; Jackson, Raymond H.

    1992-01-01

    A new second-order theory was developed for predicting the service lives of aerospace structural components. The predictions based on this new theory were compared with those based on the Ko first-order theory and the classical theory of service life predictions. The new theory gives very accurate service life predictions. An equivalent constant-amplitude stress cycle method was proposed for representing the random load spectrum for crack growth calculations. This method predicts the most conservative service life. The proposed use of minimum detectable crack size, instead of proof load established crack size as an initial crack size for crack growth calculations, could give a more realistic service life.

  10. Crystal Structure of CCM3, a Cerebral Cavernous Malformation Protein Critical for Vascular Integrity

    SciTech Connect

    Li, X.; Zhang, R; Zhang, H; He, Y; Ji, W; Min, W; Boggon, T

    2010-01-01

    CCM3 mutations are associated with cerebral cavernous malformation (CCM), a disease affecting 0.1-0.5% of the human population. CCM3 (PDCD10, TFAR15) is thought to form a CCM complex with CCM1 and CCM2; however, the molecular basis for these interactions is not known. We have determined the 2.5 {angstrom} crystal structure of CCM3. This structure shows an all {alpha}-helical protein containing two domains, an N-terminal dimerization domain with a fold not previously observed, and a C-terminal focal adhesion targeting (FAT)-homology domain. We show that CCM3 binds CCM2 via this FAT-homology domain and that mutation of a highly conserved FAK-like hydrophobic pocket (HP1) abrogates CCM3-CCM2 interaction. This CCM3 FAT-homology domain also interacts with paxillin LD motifs using the same surface, and partial CCM3 co-localization with paxillin in cells is lost on HP1 mutation. Disease-related CCM3 truncations affect the FAT-homology domain suggesting a role for the FAT-homology domain in the etiology of CCM.

  11. Crystal Structure of CCM3, a Cerebral Cavernous Malformation Protein Critical for Vascular Integrity*

    PubMed Central

    Li, Xiaofeng; Zhang, Rong; Zhang, Haifeng; He, Yun; Ji, Weidong; Min, Wang; Boggon, Titus J.

    2010-01-01

    CCM3 mutations are associated with cerebral cavernous malformation (CCM), a disease affecting 0.1–0.5% of the human population. CCM3 (PDCD10, TFAR15) is thought to form a CCM complex with CCM1 and CCM2; however, the molecular basis for these interactions is not known. We have determined the 2.5 Å crystal structure of CCM3. This structure shows an all α-helical protein containing two domains, an N-terminal dimerization domain with a fold not previously observed, and a C-terminal focal adhesion targeting (FAT)-homology domain. We show that CCM3 binds CCM2 via this FAT-homology domain and that mutation of a highly conserved FAK-like hydrophobic pocket (HP1) abrogates CCM3-CCM2 interaction. This CCM3 FAT-homology domain also interacts with paxillin LD motifs using the same surface, and partial CCM3 co-localization with paxillin in cells is lost on HP1 mutation. Disease-related CCM3 truncations affect the FAT-homology domain suggesting a role for the FAT-homology domain in the etiology of CCM. PMID:20489202

  12. The stochastic structure of critical transitions in water-stressed ecosystems

    NASA Astrophysics Data System (ADS)

    Cueto-Felgueroso, L.; Dentz, M.; Juanes, R.

    2013-12-01

    Changes in the stochastic structure of natural forcing mechanisms, such as precipitation or temperature, are likely to transform the form and function of ecological systems. Climate models and global datasets show that an increase in global temperature may result in an amplification of the hydrological cycle, not necessarily accompanied by significant changes in mean annual precipitation. In arid and semiarid environments, feedbacks between climate, soil moisture and vegetation are linked to the existence of alternative stable ecosystem states. It has been hypothesized that bistability is associated with tipping points, whereby slow changes in rainfall forcing, and random or anthropogenic disturbances, may trigger catastrophic shifts towards degraded states of the ecosystem. Identifying tipping points and characterizing ecosystem resilience are essential in the assessment of ecological services in a changing environment. We develop a stochastic framework to understand the joint probability density function (pdf) of soil moisture and vegetation biomass under stochastic rainfall. We emphasize the impact of amplified hydrological cycles on ecosystems where alternative states are possible. The joint pdf characterizes the states in which the ecosystem is most likely to be found. We show that the structure of precipitation, not just the mean annual precipitation, controls the most likely state of the ecosystem. We synthesize our analysis by proposing a definition of ecosystem resilience that is based on the modality and time dynamics of the soil moisture-biomass joint pdf.

  13. Structural basis of a rationally rewired protein-protein interface critical to bacterial signaling

    PubMed Central

    Podgornaia, Anna I.; Casino, Patricia; Marina, Alberto; Laub, Michael T.

    2013-01-01

    Summary Two-component signal transduction systems typically involve a sensor histidine kinase that specifically phosphorylates a single, cognate response regulator. This protein-protein interaction relies on molecular recognition via a small set of residues in each protein. To better understand how these residues determine the specificity of kinase-substrate interactions, we rationally rewired the interaction interface of a Thermotoga maritima two-component system, HK853-RR468, to match that found in a different two-component system, E. coli PhoR-PhoB. The rewired proteins interacted robustly with each other, but no longer interacted with the parent proteins. Analysis of the crystal structures of the wild-type and mutant protein complexes, along with a systematic mutagenesis study, reveals how individual mutations contribute to the rewiring of interaction specificity. Our approach and conclusions have implications for studies of other protein-protein interactions, protein evolution, and the design of novel protein interfaces. PMID:23954504

  14. Critical issues in the formation of quantum computer test structures by ion implantation

    SciTech Connect

    Schenkel, T.; Lo, C. C.; Weis, C. D.; Schuh, A.; Persaud, A.; Bokor, J.

    2009-04-06

    The formation of quantum computer test structures in silicon by ion implantation enables the characterization of spin readout mechanisms with ensembles of dopant atoms and the development of single atom devices. We briefly review recent results in the characterization of spin dependent transport and single ion doping and then discuss the diffusion and segregation behaviour of phosphorus, antimony and bismuth ions from low fluence, low energy implantations as characterized through depth profiling by secondary ion mass spectrometry (SIMS). Both phosphorus and bismuth are found to segregate to the SiO2/Si interface during activation anneals, while antimony diffusion is found to be minimal. An effect of the ion charge state on the range of antimony ions, 121Sb25+, in SiO2/Si is also discussed.

  15. Structural basis of a rationally rewired protein-protein interface critical to bacterial signaling.

    PubMed

    Podgornaia, Anna I; Casino, Patricia; Marina, Alberto; Laub, Michael T

    2013-09-01

    Two-component signal transduction systems typically involve a sensor histidine kinase that specifically phosphorylates a single, cognate response regulator. This protein-protein interaction relies on molecular recognition via a small set of residues in each protein. To better understand how these residues determine the specificity of kinase-substrate interactions, we rationally rewired the interaction interface of a Thermotoga maritima two-component system, HK853-RR468, to match that found in a different two-component system, Escherichia coli PhoR-PhoB. The rewired proteins interacted robustly with each other, but no longer interacted with the parent proteins. Analysis of the crystal structures of the wild-type and mutant protein complexes and a systematic mutagenesis study reveal how individual mutations contribute to the rewiring of interaction specificity. Our approach and conclusions have implications for studies of other protein-protein interactions and protein evolution and for the design of novel protein interfaces. PMID:23954504

  16. Critical review of the safety assessment of nano-structured silica additives in food.

    PubMed

    Winkler, Hans Christian; Suter, Mark; Naegeli, Hanspeter

    2016-01-01

    The development of nano-materials is viewed as one of the most important technological advances of the 21st century and new applications of nano-sized particles in the production, processing, packaging or storage of food are expected to emerge soon. This trend of growing commercialization of engineered nano-particles as part of modern diet will substantially increase oral exposure. Contrary to the proven benefits of nano-materials, however, possible adverse health effects have generally received less attention. This problem is very well illustrated by nano-structured synthetic amorphous silica (SAS), which is a common food additive since several decades although the relevant risk assessment has never been satisfactorily completed. A no observed adverse effect level of 2500 mg SAS particles/kg body weight per day was derived from the only available long-term administration study in rodents. However, extrapolation to a safe daily intake for humans is problematic due to limitations of this chronic animal study and knowledge gaps as to possible local intestinal effects of SAS particles, primarily on the gut-associated lymphoid system. This uncertainty is aggravated by digestion experiments indicating that dietary SAS particles preserve their nano-sized structure when reaching the intestinal lumen. An important aspect is whether food-borne particles like SAS alter the function of dendritic cells that, embedded in the intestinal mucosa, act as first-line sentinels of foreign materials. We conclude that nano-particles do not represent a completely new threat and that most potential risks can be assessed following procedures established for conventional chemical hazards. However, specific properties of food-borne nano-particles should be further examined and, for that purpose, in vitro tests with decision-making cells of the immune system are needed to complement existing in vivo studies. PMID:27287345

  17. Determining the influence of Itaipu Lake on thermal conditions for soybean development in adjacent lands.

    PubMed

    Wagner-Riddle, C; Werner, S S; Caramori, P; Ricce, W S; Nitsche, P; von Bertoldi, P; de Souza, E F

    2015-10-01

    Previous numerical simulations have suggested that the area adjacent to Itaipu Lake in Southern Brazil is significantly affecting the local thermal regime through development of a lake breeze. This has led to concerns that soybean growth and development, and consequently yield, has been affected by the creation of the artificial lake in this important agricultural region, but a systematic climatological study of the thermal effects of Itaipu Lake has not been conducted. The objectives of this study were to assess the spatial pattern of minimum and maximum air temperatures in a 10-km-wide area adjacent to Itaipu Lake as affected by distance from the water. Measurements were conducted over 3 years in seven transects along the shore of Itaipu Lake, with five weather stations placed in each transect. Phenological observations in soybean fields surrounding the weather stations were also conducted. Generalized additive models for location, scale, and shape (GAMLSS) analysis indicated no difference in the temperature time series as distance from water increased. Semivariograms showed that the random components in the air temperature were predominant and that there was no spatial structure to the signal. Wind direction measured over the three growing seasons demonstrated that, on average, the development of a lake breeze is limited to a few locations and a few hours of the day, supporting the temporal and spatial analysis. Phenological observations did not show differences in the timing of critical soybean stages. We suggest that the concerns that soybean development is potentially affected by the presence of Itaipu Lake are not supported by the thermal environment observed. PMID:25716222

  18. Determining the influence of Itaipu Lake on thermal conditions for soybean development in adjacent lands

    NASA Astrophysics Data System (ADS)

    Wagner-Riddle, C.; Werner, S. S.; Caramori, P.; Ricce, W. S.; Nitsche, P.; von Bertoldi, P.; de Souza, E. F.

    2015-10-01

    Previous numerical simulations have suggested that the area adjacent to Itaipu Lake in Southern Brazil is significantly affecting the local thermal regime through development of a lake breeze. This has led to concerns that soybean growth and development, and consequently yield, has been affected by the creation of the artificial lake in this important agricultural region, but a systematic climatological study of the thermal effects of Itaipu Lake has not been conducted. The objectives of this study were to assess the spatial pattern of minimum and maximum air temperatures in a 10-km-wide area adjacent to Itaipu Lake as affected by distance from the water. Measurements were conducted over 3 years in seven transects along the shore of Itaipu Lake, with five weather stations placed in each transect. Phenological observations in soybean fields surrounding the weather stations were also conducted. Generalized additive models for location, scale, and shape (GAMLSS) analysis indicated no difference in the temperature time series as distance from water increased. Semivariograms showed that the random components in the air temperature were predominant and that there was no spatial structure to the signal. Wind direction measured over the three growing seasons demonstrated that, on average, the development of a lake breeze is limited to a few locations and a few hours of the day, supporting the temporal and spatial analysis. Phenological observations did not show differences in the timing of critical soybean stages. We suggest that the concerns that soybean development is potentially affected by the presence of Itaipu Lake are not supported by the thermal environment observed.

  19. Exchange coupling between laterally adjacent nanomagnets.

    PubMed

    Dey, H; Csaba, G; Bernstein, G H; Porod, W

    2016-09-30

    We experimentally demonstrate exchange-coupling between laterally adjacent nanomagnets. Our results show that two neighboring nanomagnets that are each antiferromagnetically exchange-coupled to a common ferromagnetic bottom layer can be brought into strong ferromagnetic interaction. Simulations show that interlayer exchange coupling effectively promotes ferromagnetic alignment between the two nanomagnets, as opposed to antiferromagnetic alignment due to dipole-coupling. In order to experimentally demonstrate the proposed scheme, we fabricated arrays of pairs of elongated, single-domain nanomagnets. Magnetic force microscopy measurements show that most of the pairs are ferromagnetically ordered. The results are in agreement with micromagnetic simulations. The presented scheme can achieve coupling strengths that are significantly stronger than dipole coupling, potentially enabling far-reaching applications in Nanomagnet Logic, spin-wave devices and three-dimensional storage and computing. PMID:27535227

  20. Boundary Layers of Air Adjacent to Cylinders

    PubMed Central

    Nobel, Park S.

    1974-01-01

    Using existing heat transfer data, a relatively simple expression was developed for estimating the effective thickness of the boundary layer of air surrounding cylinders. For wind velocities from 10 to 1000 cm/second, the calculated boundary-layer thickness agreed with that determined for water vapor diffusion from a moistened cylindrical surface 2 cm in diameter. It correctly predicted the resistance for water vapor movement across the boundary layers adjacent to the (cylindrical) inflorescence stems of Xanthorrhoea australis R. Br. and Scirpus validus Vahl and the leaves of Allium cepa L. The boundary-layer thickness decreased as the turbulence intensity increased. For a turbulence intensity representative of field conditions (0.5) and for νwindd between 200 and 30,000 cm2/second (where νwind is the mean wind velocity and d is the cylinder diameter), the effective boundary-layer thickness in centimeters was equal to [Formula: see text]. PMID:16658855

  1. Application of Neutron-Absorbing Structural-Amorphous Metal (SAM) Coatings for Spent Nuclear Fuel (SNF) Container to Enhance Criticality Safety Control

    SciTech Connect

    Choi, J

    2007-01-12

    This report describes the analysis and modeling approaches used in the evaluation for criticality-control applications of the neutron-absorbing structural-amorphous metal (SAM) coatings. The applications of boron-containing high-performance corrosion-resistant material (HPCRM)--amorphous metal as the neutron-absorbing coatings to the metallic support structure can enhance criticality safety controls for spent nuclear fuel in baskets inside storage containers, transportation casks, and disposal containers. The use of these advanced iron-based, corrosion-resistant materials to prevent nuclear criticality in transportation, aging, and disposal containers would be extremely beneficial to the nuclear waste management programs.

  2. Structural determinants of RGS-RhoGEF signaling critical to Entamoeba histolytica pathogenesis.

    PubMed

    Bosch, Dustin E; Kimple, Adam J; Manning, Alyssa J; Muller, Robin E; Willard, Francis S; Machius, Mischa; Rogers, Stephen L; Siderovski, David P

    2013-01-01

    G protein signaling pathways, as key components of physiologic responsiveness and timing, are frequent targets for pharmacologic intervention. Here, we identify an effector for heterotrimeric G protein α subunit (EhGα1) signaling from Entamoeba histolytica, the causative agent of amoebic colitis. EhGα1 interacts with this effector and guanosine triphosphatase-accelerating protein, EhRGS-RhoGEF, in a nucleotide state-selective fashion. Coexpression of EhRGS-RhoGEF with constitutively active EhGα1 and EhRacC leads to Rac-dependent spreading in Drosophila S2 cells. EhRGS-RhoGEF overexpression in E. histolytica trophozoites leads to reduced migration toward serum and lower cysteine protease activity, as well as reduced attachment to, and killing of, host cells. A 2.3 Å crystal structure of the full-length EhRGS-RhoGEF reveals a putative inhibitory helix engaging the Dbl homology domain Rho-binding surface and the pleckstrin homology domain. Mutational analysis of the EhGα1/EhRGS-RhoGEF interface confirms a canonical "regulator of G protein signaling" domain rather than a RhoGEF-RGS ("rgRGS") domain, suggesting a convergent evolution toward heterotrimeric and small G protein cross-talk. PMID:23260656

  3. Structural Determinants of RGS-RhoGEF Signaling Critical to Entamoeba histolytica Pathogenesis

    PubMed Central

    Bosch, Dustin E.; Kimple, Adam J.; Manning, Alyssa J.; Muller, Robin E.; Willard, Francis S.; Machius, Mischa; Rogers, Stephen L.; Siderovski, David P.

    2012-01-01

    Summary G-protein signaling pathways, as key components of physiologic responsiveness and timing, are frequent targets for pharmacologic intervention. Here, we identify an effector for heterotrimeric G-protein α subunit (EhGα1) signaling from Entamoeba histolytica, the causative agent of amoebic colitis. EhGα1 interacts with this effector and GTPase-accelerating protein (GAP), EhRGS-RhoGEF, in a nucleotide state-selective fashion. Co-expression of EhRGS-RhoGEF with constitutively active EhGα1 and EhRacC leads to Rac-dependent spreading in Drosophila S2 cells. EhRGS-RhoGEF overexpression in E. histolytica trophozoites leads to reduced migration toward serum and lower cysteine protease activity, as well as reduced attachment to, and killing of, host cells. A 2.3 Å crystal structure of the full-length EhRGS-RhoGEF reveals a putative inhibitory helix engaging the DH domain Rho-binding surface and the PH domain. Mutational analysis of the EhGα1/EhRGS-RhoGEF interface confirms a canonical RGS domain rather than a RhoGEF-RGS (“rgRGS”) domain, suggesting a convergent evolution toward heterotrimeric and small G-protein cross-talk. PMID:23260656

  4. Dramatic changes in DNA conductance with stretching: structural polymorphism at a critical extension.

    PubMed

    Bag, Saientan; Mogurampelly, Santosh; Goddard Iii, William A; Maiti, Prabal K

    2016-09-21

    In order to interpret recent experimental studies of the dependence of conductance of ds-DNA as the DNA is pulled from the 3'end1-3'end2 ends, which find a sharp conductance jump for a very short (4.5%) stretching length, we carried out multiscale modeling to predict the conductance of dsDNA as it is mechanically stretched to promote various structural polymorphisms. We calculate the current along the stretched DNA using a combination of molecular dynamics simulations, non-equilibrium pulling simulations, quantum mechanics calculations, and kinetic Monte Carlo simulations. For 5'end1-5'end2 attachments we find an abrupt jump in the current within a very short stretching length (6 Å or 17%) leading to a melted DNA state. In contrast, for 3'end1-3'end2 pulling it takes almost 32 Å (84%) of stretching to cause a similar jump in the current. Thus, we demonstrate that charge transport in DNA can occur over stretching lengths of several nanometers. We find that this unexpected behaviour in the B to S conformational DNA transition arises from highly inclined base pair geometries that result from this pulling protocol. We found that the dramatically different conductance behaviors for two different pulling protocols arise from how the hydrogen bonds of DNA base pairs break. PMID:27545499

  5. 30 CFR 56.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance on adjacent tracks. 56.9103 Section..., Hauling, and Dumping Traffic Safety § 56.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  6. 30 CFR 57.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Clearance on adjacent tracks. 57.9103 Section..., Hauling, and Dumping Traffic Safety § 57.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  7. 30 CFR 56.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Clearance on adjacent tracks. 56.9103 Section..., Hauling, and Dumping Traffic Safety § 56.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  8. 30 CFR 57.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance on adjacent tracks. 57.9103 Section..., Hauling, and Dumping Traffic Safety § 57.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  9. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  10. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  11. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  12. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  13. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  14. Study of Local Seismic Events in Lithuania and Adjacent Areas Using Data from the PASSEQ Experiment

    NASA Astrophysics Data System (ADS)

    Janutyte, Ilma; Kozlovskaya, Elena; Motuza, Gediminas

    2013-05-01

    The territory of Lithuania and adjacent areas of the East European Craton have always been considered a region of low seismicity. Two recent earthquakes with magnitudes of more than 5 in the Kaliningrad District (Russian Federation) on 21 September 2004 motivated re-evaluation of the seismic hazard in Lithuania and adjacent territories. A new opportunity to study seismicity in the region is provided by the PASSEQ (Pasive Seismic Experiment) project that aimed to study the lithosphere-asthenosphere structure around the Trans-European Suture Zone. Twenty-six seismic stations of the PASSEQ temporary seismic array were installed in the territory of Lithuania. The stations recorded a number of local and regional seismic events originating from Lithuania and adjacent areas. This data can be used to answer the question of whether there exist seismically active tectonic zones in Lithuania that could be potentially hazardous for critical industrial facilities. Therefore, the aim of this paper is to find any natural tectonic seismic events in Lithuania and to obtain more general view of seismicity in the region. In order to do this, we make a manual review of the continuous data recorded by the PASSEQ seismic stations in Lithuania. From the good quality data, we select and relocate 45 local seismic events using the well-known LocSAT and VELEST location algortithms. In order to discriminate between possible natural events, underwater explosions and on-shore blasts, we analyse spatial distribution of epicenters and temporal distribution of origin times and perform both visual analysis of waveforms and spectral analysis of recordings. We show that the relocated seismic events can be grouped into five clusters (groups) according to their epicenter coordinates and origin and that several seismic events might be of tectonic origin. We also show that several events from the off-shore region in the Baltic Sea (at the coasts of the Kaliningrad District of the Russian Federation) are

  15. The Long-Range Model of High-L Rydberg Fine Structure: A Critical Comparison with Experimental Data..

    NASA Astrophysics Data System (ADS)

    Snow, Erica L.; Wright, Laura E.; Lundeen, Stephen R.

    2006-05-01

    A simple view of the fine structure of non-penetrating Rydberg levels, suggested over 70 years ago [1], was refined to treat the fine structure of helium, lithium [2], and other atoms with S-state ion cores [3]. In this view the ion polarizabilities determine the fine structure pattern. Current experimental techniques provide access to highly excited high-L states in He [4], Li [5], Mg, SiIII [6], and Ba[7], and a test of the long-range model is possible with the availability of independent theoretical calculations. A critical comparison of the data treated with the long-range model will be made to the a-priori calculations of the ionic polarizabilities. [1] Joseph E. Mayer and Maria Goeppert Mayer, Phys. Rev. 43 605 (1933). [2] Richard J. Drachman and A. K. Bhatia, Phys. Rev. A 51 2926 (1995). [3] C. Laughlin, J. Phys. B: At. Mol. Opt. Phys. 28 2787 (1995). [4] G. D. Stevens and S. R. Lundeen, Comments on At. and Mol. Phys., Comments on Mod. Phys. 1,D 207 (2000). [5] C. H. Storry, N. E. Rothery, and E. A. Hessels, Phys. Rev. A 55 128 (1997). [6] R. A. Komara et. al., J. Phys. B: At. Mol. Opt. Phys. 38 S87 (2005). [7] E.L. Snow, et. al. Phys. Rev. A 71, 022510 (2005)

  16. Thorax, Trachea, and Lung Ultrasonography in Emergency and Critical Care Medicine: Assessment of an Objective Structured Training Concept

    PubMed Central

    Breitkreutz, Raoul; Dutiné, Martina; Scheiermann, Patrick; Kujumdshiev, Sandy; Ackermann, Hanns; Seeger, Florian Hartmut; Walcher, Felix; Hirche, Tim Oliver

    2013-01-01

    Background and Study objective. Focused lung ultrasound (LUS) examinations are important tools in critical care medicine. There is evidence that LUS can be used for the detection of acute thoracic lesions. However, no validated training method is available. The goal of this study was to develop and assess an objective structured clinical examination (OSCE) curriculum for focused thorax, trachea, and lung ultrasound in emergency and critical care medicine (THOLUUSE). Methods. 39 trainees underwent a one-day training course in a prospective educational study, including lectures in sonoanatomy and -pathology of the thorax, case presentations, and hands-on training. Trainees' pre- and posttest performances were assessed by multiple choice questionnaires, visual perception tests by interpretation video clips, practical performance of LUS, and identification of specific ultrasound findings. Results. Trainees postcourse scores of correct MCQ answers increased from 56 ± 4% to 82 ± 2% (mean± SD; P < 0.001); visual perception skills increased from 54 ± 5% to 78 ± 3% (P < 0.001); practical ultrasound skills improved, and correct LUS was performed in 94%. Subgroup analysis revealed that learning success was independent from the trainees' previous ultrasound experience. Conclusions. THOLUUSE significantly improves theoretical and practical skills for the diagnosis of acute thoracic lesions. We propose to implement THOLUUSE in emergency medicine training. PMID:24369503

  17. Murine Fam65b forms ring-like structures at the base of stereocilia critical for mechanosensory hair cell function.

    PubMed

    Zhao, Bo; Wu, Zizhen; Müller, Ulrich

    2016-01-01

    Cochlear hair cells convert sound-induced vibration into electrical signals. FAM65B mutations cause hearing loss by an unknown mechanism. Using biochemistry and stochastic optical reconstruction microscopy (STORM), we show here that Fam65b oligomers form a circumferential ring near the basal taper of the mechanically sensitive stereocilia of murine hair cells. Taperin, a second protein near the taper, forms a dense-core-like structure that is disrupted in the absence of Fam65b. Stereocilia of Fam65b-deficient murine hair cells start to develop, but mechanotransduction is affected and stereocilia deteriorate. Yeast-two-hybrid screens identify RhoC as a Fam65b binding partner. RhoC co-localizes with Fam65b in stereocilia and regulates Fam65b oligomerization. Binding to RhoC and oligomerization are critical for Fam65b function. Our findings thus reveal a highly organized compartment near the base of stereocilia that is critical for hair cell function and affected in disease. PMID:27269051

  18. A CapG gain-of-function mutant reveals critical structural and functional determinants for actin filament severing

    PubMed Central

    Zhang, Y; Vorobiev, Sergey M; Gibson, Bruce G; Hao, Binghua; Sidhu, Gurjit S; Mishra, Vishnu S; Yarmola, Elena G; Bubb, Michael R; Almo, Steven C; Southwick, Frederick S

    2006-01-01

    CapG is the only member of the gelsolin family unable to sever actin filaments. Changing amino acids 84–91 (severing domain) and 124–137 (WH2-containing segment) simultaneously to the sequences of gelsolin results in a mutant, CapG-sev, capable of severing actin filaments. The gain of severing function does not alter actin filament capping, but is accompanied by a higher affinity for monomeric actin, and the capacity to bind and sequester two actin monomers. Analysis of CapG-sev crystal structure suggests a more loosely folded inactive conformation than gelsolin, with a shorter S1–S2 latch. Calcium binding to S1 opens this latch and S1 becomes separated from a closely interfaced S2–S3 complex by an extended arm consisting of amino acids 118–137. Modeling with F-actin predicts that the length of this WH2-containing arm is critical for severing function, and the addition of a single amino acid (alanine or histidine) eliminates CapG-sev severing activity, confirming this prediction. We conclude that efficient severing utilizes two actin monomer-binding sites, and that the length of the WH2-containing segment is a critical functional determinant for severing. PMID:16977317

  19. Murine Fam65b forms ring-like structures at the base of stereocilia critical for mechanosensory hair cell function

    PubMed Central

    Zhao, Bo; Wu, Zizhen; Müller, Ulrich

    2016-01-01

    Cochlear hair cells convert sound-induced vibration into electrical signals. FAM65B mutations cause hearing loss by an unknown mechanism. Using biochemistry and stochastic optical reconstruction microscopy (STORM), we show here that Fam65b oligomers form a circumferential ring near the basal taper of the mechanically sensitive stereocilia of murine hair cells. Taperin, a second protein near the taper, forms a dense-core-like structure that is disrupted in the absence of Fam65b. Stereocilia of Fam65b-deficient murine hair cells start to develop, but mechanotransduction is affected and stereocilia deteriorate. Yeast-two-hybrid screens identify RhoC as a Fam65b binding partner. RhoC co-localizes with Fam65b in stereocilia and regulates Fam65b oligomerization. Binding to RhoC and oligomerization are critical for Fam65b function. Our findings thus reveal a highly organized compartment near the base of stereocilia that is critical for hair cell function and affected in disease. DOI: http://dx.doi.org/10.7554/eLife.14222.001 PMID:27269051

  20. Austenitic structure formation in an Fe-32% Ni alloy during slow heating in the critical temperature range

    NASA Astrophysics Data System (ADS)

    Zemtsova, N. D.

    2014-08-01

    Electron diffraction is used to show (for the first time) that the reverse α → γ transformation in an Fe-32% Ni during slow heating develops via the formation of an intermediate paramagnetic 9 R phase. Coarse extended lamellae form according to a shear mechanism in the central part of the temperature range of the reverse transformation, which is called the critical range (here, the physical properties of the alloy change anomalously). The extended lamellae consist of 9 R-phase lamellae with γ-phase interlayers. A high density of periodic stacking faults in the structure of the 9 R phase and a high density of chaotic stacking faults in the complex 9 R + γ phase determine the nature of phase transformation-induced hardening.

  1. Integrating hydrogeophysics and hydrological tracers to characterise the spatial structure of groundwater storage in the critical zone of montane environments

    NASA Astrophysics Data System (ADS)

    Dick, J.; Tetzlaff, D.; Bradford, J.; Soulsby, C.

    2015-12-01

    It is increasingly recognised that groundwater (GW) in montane watersheds has a major influence on the distribution of vegetation communities and ecosystem function, as well as sustaining downstream river flows. In glaciated landscapes, complex and heterogenous drift deposits can have a dominant influence on GW stores and fluxes, and form a poorly understood component of the critical zone. Given the logistical problems and limitations of drilling observation wells in such terrain, hydrogeophysics has outstanding potential to help characterise aquifer structure and understand shallow GW in the critical zone of montane environments. We present the results of electrical resistivity tomography (ERT) surveys in an intensively monitored 3.2km2 watershed in the Scottish Highlands with a strong glacial past. We sought to characterise the structure and spatial organisation of GW stores in diverse quaternary drift deposits. This utilized distributed ERT transects that provided a basis for spatial interpolation using geostatistical methods and high resolution LiDAR surveys. Some transects coincided with shallow observation wells that were used to "ground-truth" the inversion of resistivity data. The surveys showed that the drifts covered around 70% of the catchment and varied from 5m deep on the hillslopes to 40m in the valleys. The water table was within 0.2m of the soil surface in the valley bottom areas and about 1.5m deep on steeper hillslopes. The water content of drifts inferred by the ERT surveys and characterisation of the aquifer properties showed highest water content in the peat (~80%) and basal till (20-30%), and low storage in moraine deposits (10%). Upscaling these estimates of inferred storage to the catchment scale indicated around ~2-3 m of GW storage, equivalent to around 4-6 years of effective precipitation. This generally compared well with independent storage estimates inferred from long-term stable isotope time series collected from the aquifers

  2. A properly configured ring structure is critical for the function of the mitochondrial DNA recombination protein, Mgm101.

    PubMed

    Nardozzi, Jonathan D; Wang, Xiaowen; Mbantenkhu, MacMillan; Wilkens, Stephan; Chen, Xin Jie

    2012-10-26

    Mgm101 is a Rad52-type recombination protein of bacteriophage origin required for the repair and maintenance of mitochondrial DNA (mtDNA). It forms large oligomeric rings of ∼14-fold symmetry that catalyze the annealing of single-stranded DNAs in vitro. In this study, we investigated the structural elements that contribute to this distinctive higher order structural organization and examined its functional implications. A pair of vicinal cysteines, Cys-216 and Cys-217, was found to be essential for mtDNA maintenance. Mutations to the polar serine, the negatively charged aspartic and glutamic acids, and the hydrophobic amino acid alanine all destabilize mtDNA in vivo. The alanine mutants have an increased propensity of forming macroscopic filaments. In contrast, mutations to aspartic acid drastically destabilize the protein and result in unstructured aggregates with severely reduced DNA binding activity. Interestingly, the serine mutants partially disassemble the Mgm101 rings into smaller oligomers. In the case of the C216S mutant, a moderate increase in DNA binding activity was observed. By using small angle x-ray scattering analysis, we found that Mgm101 forms rings of ∼200 Å diameter in solution, consistent with the structure previously established by transmission electron microscopy. We also found that the C216A/C217A double mutant tends to form broken rings, which likely provide free ends for seeding the growth of the super-stable but functionally defective filaments. Taken together, our data underscore the importance of a delicately maintained ring structure critical for Mgm101 activity. We discuss a potential role of Cys-216 and Cys-217 in regulating Mgm101 function and the repair of damaged mtDNA under stress conditions. PMID:22948312

  3. Ambient pressure structural quantum critical point in the phase diagram of (Ca(x)Sr(1-x))(3)Rh(4)Sn(13).

    PubMed

    Goh, S K; Tompsett, D A; Saines, P J; Chang, H C; Matsumoto, T; Imai, M; Yoshimura, K; Grosche, F M

    2015-03-01

    The quasiskutterudite superconductor Sr_{3}Rh_{4}Sn_{13} features a pronounced anomaly in electrical resistivity at T^{*}∼138  K. We show that the anomaly is caused by a second-order structural transition, which can be tuned to 0 K by applying physical pressure and chemical pressure via the substitution of Ca for Sr. A broad superconducting dome is centered around the structural quantum critical point. Detailed analysis of the tuning parameter dependence of T^{*} as well as insights from lattice dynamics calculations strongly support the existence of a structural quantum critical point at ambient pressure when the fraction of Ca is 0.9 (i.e., x_{c}=0.9). This establishes the (Ca_{x}Sr_{1-x})_{3}Rh_{4}Sn_{13} series as an important system for exploring the physics of structural quantum criticality without the need of applying high pressures. PMID:25793843

  4. Interaction between adjacent lightning discharges in clouds

    NASA Astrophysics Data System (ADS)

    Wang, Yanhui; Zhang, Guangshu; Zhang, Tong; Li, Yajun; Wu, Bin; Zhang, Tinglong

    2013-07-01

    Using a 3D lightning radiation source locating system (LLS), three pairs of associated lightning discharges (two or more adjacent lightning discharges following an arbitrary rule that their space-gap was less than 10 km and their time-gap was less than 800 ms) were observed, and the interaction between associated lightning discharges was analyzed. All these three pairs of associated lightning discharges were found to involve three or more charge regions (the ground was considered as a special charge region). Moreover, at least one charge region involved two lightning discharges per pair of associated lightning discharges. Identified from electric field changes, the subsequent lightning discharges were suppressed by the prior lightning discharges. However, it is possible that the prior lightning discharge provided a remaining discharge channel to facilitate the subsequent lightning discharge. The third case provided evidence of this possibility. Together, the results suggested that, if the charges in the main negative charge region can be consumed using artificial lightning above the main negative charge regions, lightning accidents on the ground could be greatly reduced, on the condition that the height of the main negative charge region and the charge intensity of the lower positive charge region are suitable.

  5. Structures adjacent to the Purcell Trench south of Sandpoint, Idaho

    SciTech Connect

    McCarthy, P.T.; Miller, D.M.; Nakata, J.K. ); Hoisch, T.D. )

    1993-04-01

    The Purcell Trench of southern British Columbia and northern Idaho marks the location of an Eocene, east-dipping normal fault that juxtaposes migmatite and coarsely crystalline rocks on the west with relatively unmetamorphosed rocks of the Belt Supergroup and shallow plutons on the east. Well west of the projected Purcell Trench, a broad zone of plastic shearing may record movement on the Purcell Trench fault, but as a deeper manifestation. Mylonitic fabrics in the pre-Tertiary igneous rocks of this zone are diffuse, but outline a shear zone that dips southeast, records top-to-the-east simple shear, and is arched about a NW axis. Preliminary barometric data, pervasively reset Eocene K-Ar ages for biotite and hornblende, and late-kinematic emplacement of a mesozonal 50 Ma (U-Pb zircon) granite all point to a mid-crustal location for the shear zone. However, the rocks lack the intense fabrics and pervasive deformation typical of well-developed mid-crustal shear zones, indicating a discrepancy between the amount of strain accommodated in the rocks south of Sandpoint and the offset generally attributed to the Purcell Trench fault north of Sandpoint. Strain values for the most deformed rocks in the shear zone are about [gamma] = 1.7 based on petrofabric studies, which allows for roughly 5 km of offset across the zone. The lesser offset south of Sandpoint, coupled with lack of brittle deformation in the zone, require a separate mechanism for exhuming rocks in and near the zone. The authors propose that offset on the Newport fault, northwest of Sandpoint, increased southward and accommodated decreased offset on the Purcell Trench fault. Movement on the Newport fault exhumed the midcrustal rocks of the shear zone.

  6. High-speed scanning of critical structures in aviation using coordinate measurement machine and the laser ultrasonic.

    PubMed

    Swornowski, Pawel J

    2012-01-01

    Aviation is one of the know-how spheres containing a great deal of responsible sub-assemblies, in this case landing gear. The necessity for reducing production cycle times while achieving better quality compels metrologists to look for new and improved ways to perform inspection of critical structures. This article describes the ability to determine the shape deviation and location of defects in landing gear using coordinate measuring machines and laser ultrasonic with high-speed scanning. A nondestructive test is the basis for monitoring microcrack and corrosion propagation in the context of a damage-tolerant design approach. This article presents an overview of the basics and of the various metrological aspects of coordinate measurement and a nondestructive testing method in terms of high-speed scanning. The new test method (laser ultrasonic) promises to produce the necessary increase in inspection quality, but this is limited by the wide range of materials, geometries, and structure aeronautic parts used. A technique combining laser ultrasonic and F-SAFT (Fourier-Synthetic Aperture Focusing Technique) processing has been proposed for the detection of small defects buried in landing gear. The experimental results of landing gear inspection are also presented. PMID:22700384

  7. Ares I-X Upper Stage Simulator Structural Analyses Supporting the NESC Critical Initial Flaw Size Assessment

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.; Phillips, Dawn R.; Raju, Ivatury S.

    2008-01-01

    The structural analyses described in the present report were performed in support of the NASA Engineering and Safety Center (NESC) Critical Initial Flaw Size (CIFS) assessment for the ARES I-X Upper Stage Simulator (USS) common shell segment. The structural analysis effort for the NESC assessment had three thrusts: shell buckling analyses, detailed stress analyses of the single-bolt joint test; and stress analyses of two-segment 10 degree-wedge models for the peak axial tensile running load. Elasto-plastic, large-deformation simulations were performed. Stress analysis results indicated that the stress levels were well below the material yield stress for the bounding axial tensile design load. This report also summarizes the analyses and results from parametric studies on modeling the shell-to-gusset weld, flange-surface mismatch, bolt preload, and washer-bearing-surface modeling. These analyses models were used to generate the stress levels specified for the fatigue crack growth assessment using the design load with a factor of safety.

  8. A GIS based urban flood risk analysis model for vulnerability assessment of critical structures during flood emergencies

    NASA Astrophysics Data System (ADS)

    Albano, R.; Sole, A.; Adamowski, J.; Mancusi, L.

    2014-04-01

    Risk analysis has become a priority for authorities and stakeholders in many European countries, with the aim of reducing flooding risk by considering the priority and benefits of possible interventions. Within this context, a flood risk analysis model was developed in this study that is based on GIS, and integrated with a model that assesses the degree of accessibility and operability of strategic emergency response structures in an urban area. The proposed model is unique in that it provides a quantitative estimation of flood risk on the basis of the operability of the strategic emergency structures in an urban area, their accessibility, and connection within the urban system of a city (i.e., connection between aid centres and buildings at risk) in the emergency phase. The results of a case study in the Puglia Region in Southern Italy are described to illustrate the practical applications of this newly proposed approach. The main advantage of the proposed approach is that it allows for the defining of a hierarchy between different infrastructures in the urban area through the identification of particular components whose operation and efficiency are critical for emergency management. This information can be used by decision makers to prioritize risk reduction interventions in flood emergencies in urban areas.

  9. Critical Heat Flux for Downward-Facing Boiling on a Coated Hemispherical Vessel Surrounded by an Insulation Structure

    SciTech Connect

    J. Yang; F. B. Cheung; J. L. Rempe; K. Y. Suh; S. B. Kim

    2005-05-01

    An experimental study was performed to evaluate the effects of surface coating and an enhanced insulation structure on the downward facing boiling process and the critical heat flux on the outer surface of a hemispherical vessel. Steady-state boiling tests were conducted in the Subscale Boundary Layer Boiling (SBLB) facility using an enhanced vessel/insulation design for the cases with and without vessel coatings. Based on the boiling data, CHF correlations were obtained for both plain and coated vessels. It was found that the nucleate boiling rates and the local CHF limits for the case with micro-porous layer coating were consistently higher than those values for a plain vessel at the same angular location. The enhancement in the local CHF limits and nucleate boiling rates was mainly due to the micro-porous layer coating that increased the local liquid supply rate toward the vaporization sites on the vessel surface. For the case with thermal insulation, the local CHF limit tended to increase from the bottom center at first, then decrease toward the minimum gap location, and finally increase toward the equator. This nonmonotonic behavior, which differed significantly from the case without thermal insulation, was evidently due to the local variation of the two-phase motions in the annular channel between the test vessel and the insulation structure.

  10. An engineered dimeric protein pore that spans adjacent lipid bilayers

    PubMed Central

    Mantri, Shiksha; Sapra, K. Tanuj; Cheley, Stephen; Sharp, Thomas H.; Bayley, Hagan

    2013-01-01

    The bottom-up construction of artificial tissues is an underexplored area of synthetic biology. An important challenge is communication between constituent compartments of the engineered tissue and between the engineered tissue and additional compartments, including extracellular fluids, further engineered tissue and living cells. Here we present a dimeric transmembrane pore that can span two adjacent lipid bilayers and thereby allow aqueous compartments to communicate. Two heptameric staphylococcal α-hemolysin (αHL) pores were covalently linked in an aligned cap-to-cap orientation. The structure of the dimer, (α7)2, was confirmed by biochemical analysis, transmission electron microscopy (TEM) and single-channel electrical recording. We show that one of two β barrels of (α7)2 can insert into the lipid bilayer of a small unilamellar vesicle, while the other spans a planar lipid bilayer. (α7)2 pores spanning two bilayers were also observed by TEM. PMID:23591892

  11. Preventing Proximal Adjacent Level Kyphosis With Strap Stabilization.

    PubMed

    Zaghloul, Khaled M; Matoian, Brett J; Denardin, Nicholas B; Patel, Vikas V

    2016-07-01

    A substantial proportion of patients develop proximal junctional kyphosis following spinal surgery. To combat this postoperative change, several techniques have focused on maintaining the structural integrity of adjacent spinal levels and adapting the proximal end of the fusion construct to accommodate the increased mechanical stressors produced by long spinal fusion. The use of Mersilene tape (Ethicon, Somerville, New Jersey) for spine and orthopedic surgery is well documented, although considerably less is known about its use for preventing proximal junctional kyphosis. This article describes a proposed technique using Mersilene tape to provide a check-rein strap stabilization at the proximal end of fusion constructs. Initial data suggest that use of this technique may prevent formation of proximal junctional kyphosis. [Orthopedics. 2016; 39(4):e794-e799.]. PMID:27158827

  12. Geomorphology of portions of western Kentucky and adjacent areas

    SciTech Connect

    Dilamarter, R.C.

    1982-07-01

    The geomorphology of portions of western Kentucky and adjacent areas in Indiana, Illinois and Tennessee is presented as a background for interpreters evaluating the present land surface using remotely sensed imagery. Eight physiographic units were analyzed and are briefly discussed with reference to topography and surface deposits. Great diversity was found to be characteristic of the region, the result of different structural influences and geomorphic processes. The landscape bears the marks of fluvial, glacial, eolian, lacustrine and karstic environments, so a regional geomorphic history was compiled from the literature as an aid to understanding the land surface. Three smaller zones in Kentucky were analyzed in greater detail regarding topography and geomorphic development because of their potential importance in subsurface exploration.

  13. Critical dimension small angle X-ray scattering measurements of FinFET and 3D memory structures

    NASA Astrophysics Data System (ADS)

    Settens, Charles; Bunday, Benjamin; Thiel, Brad; Kline, R. Joseph; Sunday, Daniel; Wang, Chengqing; Wu, Wen-li; Matyi, Richard

    2013-04-01

    We have demonstrated that transmission critical dimension small angle X-ray scattering (CD-SAXS) provides high accuracy and precision CD measurements on advanced 3D microelectronic architectures. The competitive advantage of CD-SAXS over current 3D metrology methods such as optical scatterometry is that CD-SAXS is able to decouple and fit cross-section parameters without any significant parameter cross-correlations. As the industry aggressively scales beyond the 22 nm node, CD-SAXS can be used to quantitatively measure nanoscale deviations in the average crosssections of FinFETs and high-aspect ratio (HAR) memory devices. Fitting the average cross-section of 18:1 isolated HAR contact holes with an effective trapezoid model yielded an average pitch of 796.9 +/- 0.4 nm, top diameter of 70.3 +/- 0.9 nm, height of 1088 +/- 4 nm, and sidewall angle below 0.1°. Simulations of dense 40:1 HAR contact holes and FinFET fin-gate crossbar structures have been analyzed using CD-SAXS to inquire the theoretical precision of the technique to measure important process parameters such as fin CD, height, and sidewall angle; BOX etch recess, thickness of hafnium oxide and titanium nitride layers; gate CD, height, and sidewall angle; and hafnium oxide and titanium nitride etch recess. The simulations of HAR and FinFET structures mimic the characteristics of experimental data collected at a synchrotron x-ray source. Using the CD-SAXS simulator, we estimate the measurement capabilities for smaller similar structures expected at future nodes to predict the applicability of this technique to fulfill important CD metrology needs.

  14. Structural and Geomorphic Controls on Dryland Salinity and Regolith Distribution in the Critical Zone, North-east Tasmania, Australia.

    NASA Astrophysics Data System (ADS)

    Sweeney, M. E.; Moore, C. L.

    2015-12-01

    Salinity occurs in the drier and flatter Australian landscapes because there is insufficient rain to flush salts from critical zone. Changes in land use due to agriculture and urbanisation can accelerate salinity effects, leading to soil and water degradation and threatening infrastructure and ecosystems. The dominant lithology in the salt affected regions of North-east Tasmania is dolerite. The geochemistry of dolerite regolith has been examined in order to understand the association between salinity and weathered dolerite. The electrical conductivity of 1:5 soil-waters is higher in the more weathered material (maximum 4.9 dS/m). This confirms field observations that highly weathered dolerite can serve as a significant store for salt in the landscape. However, the clay content and salinity varies, depending on the local geomorphic context. Dolerite weathering on well-drained slopes has favoured the formation of 1:1 kaolinite clays, and sometimes bauxite formation. Kaolinite-bearing regolith can store salt via matrix diffusion processes. However, there are fault-bounded pockets of colluvium and highly-weathered in situmaterial, where the supply of cations has not been diminished and 2:1 montmorillonite clays dominate. These regions have the capacity to store large volumes of salts. The geomorphology also affects the volume of rain and flux of salt from windblown dust and oceanic aerosols. The chemistry of rainwater from an array of bulk deposition collectors was studied from Spring 2013 to Winter 2014. The average salt flux was 79± 10 kg/ha/yr in the study region, ranging from 170± 12 kg/ha/yr in the north to 42 ± 6 kg/ha/yr inland. To assist in understanding why salt is found in certain parts of the landscape but not in others, it is essential to model how water moves through the critical zone and geological structures. By exploring the complex interactions of geomorphology and other biophysical parameters the study area has been divided into Hydrogeological

  15. Hydrocarbon provinces and productive trends in Libya and adjacent areas

    SciTech Connect

    Missallati, A.A. Ltd., Tripoli )

    1988-08-01

    According to the age of major reservoirs, hydrocarbon occurrences in Libya and adjacent areas can be grouped into six major systems which, according to their geographic locations, can be classified into two major hydrocarbon provinces: (1) Sirte-Pelagian basins province, with major reservoirs ranging from middle-late Mesozoic to early Tertiary, and (2) Murzog-Ghadames basins province, with major reservoirs ranging from early Paleozoic to early Mesozoic. In the Sirte-Pelagian basins province, hydrocarbons have been trapped in structural highs or in stratigraphic wedge-out against structural highs and in carbonate buildups. Here, hydrocarbon generation is characterized by the combined effect of abundant structural relief and reservoir development in the same hydrocarbon systems of the same age, providing an excellent example of hydrocarbon traps in sedimentary basins that have undergone extensive tensional fracturing in a shallow marine environment. In the Murzog-Ghadames basins province, hydrocarbons have been trapped mainly in structural highs controlled by paleostructural trends as basement arches which acted as focal points for oil migration and accumulation.

  16. Probabilistic Structural Analysis Methods for select space propulsion system components (PSAM). Volume 2: Literature surveys of critical Space Shuttle main engine components

    NASA Technical Reports Server (NTRS)

    Rajagopal, K. R.

    1992-01-01

    The technical effort and computer code development is summarized. Several formulations for Probabilistic Finite Element Analysis (PFEA) are described with emphasis on the selected formulation. The strategies being implemented in the first-version computer code to perform linear, elastic PFEA is described. The results of a series of select Space Shuttle Main Engine (SSME) component surveys are presented. These results identify the critical components and provide the information necessary for probabilistic structural analysis. Volume 2 is a summary of critical SSME components.

  17. Experimental Verification of a Critical Condition for the Formation of As-Cast Coarse Columnar Austenite Grain Structure in a Hyperperitectic Carbon Steel

    NASA Astrophysics Data System (ADS)

    Ohno, Munekazu; Maruyama, Masato; Matsuura, Kiyotaka

    2015-11-01

    Experimental verification of a critical condition for the formation of coarse columnar γ grain (CCG) structure in as-cast hyperperitectic carbon steels, which was put forward based on theories of grain growth and phase-field simulations in early studies, is carried out by means of a Bridgman-type directional solidification experiment. The occurrence of the discontinuous and continuous grain growth processes and the resulting formation of CCG and equiaxed γ grain structures, respectively, are demonstrated. Importantly, these changes of the as-cast microstructures and the grain growth modes are in excellent agreement with the previously proposed critical condition of the CCG formation.

  18. Upper critical field of KFe2As2 under pressure: A test for the change in the superconducting gap structure

    SciTech Connect

    Taufour, Valentin; Foroozani, Neda; Tanatar, Makariy A.; Lim, Jinhyuk; Kaluarachchi, Udhara; Kim, Stella K.; Liu, Yong; Lograsso, Thomas A.; Kogan, Vladimir G.; Prozorov, Ruslan; Bud'ko, Sergey L.; Schilling, James S.; Canfield, Paul C.

    2014-06-01

    We report measurements of electrical resistivity under pressure to 5.8 GPa, magnetization to 6.7 GPa, and ac susceptibility to 7.1 GPa in KFe2As2. The previously reported change of slope in the pressure dependence of the superconducting transition temperature Tc(p) at a pressure p*~1.8 GPa is confirmed, and Tc(p) is found to be nearly constant above p* up to 7.1 GPa. The T-p phase diagram is very sensitive to the pressure conditions as a consequence of the anisotropic uniaxial pressure dependence of Tc. Across p*, a change in the behavior of the upper critical field is revealed through a scaling analysis of the slope of Hc2 with the effective mass as determined from the A coefficient of the T2 term of the temperature-dependent resistivity. We show that this scaling provides a quantitative test for the changes of the superconducting gap structure and suggests the development of a kz modulation of the superconducting gap above p* as a most likely explanation.

  19. The Importance of Southern Hemisphere CZOs for Evaluating Spatial Patterns of Chemical Structure in the Critical Zone and Assisting Human Development

    NASA Astrophysics Data System (ADS)

    Chadwick, O.

    2014-12-01

    The US Critical Zone Exploration Network (CZEN) is a network of sites designed to provide a better understanding of the integrated Earth surface system. The capacity of the critical zone to withstand perturbations, whether driven by climate, land use change, or spread of invasive species, depends on its chemical composition and physical state, which in turn depends on the time evolution of the critical zone. Many temperate and/or tectonically active critical zones contain a relatively short history due to rapid erosion but tectonically quiescent, tropical regions of the planet contain much longer records that need to be understood to cover the full suite of critical zone processes. Southern Hemisphere Critical Zone Observatories such as those proposed for Kruger National Park (KNP) in South Africa and for portions of the Yilgarn Craton in Western Australa will allow us to extend our temporal understanding of development of spatial heterogeneity in the chemical and physical structure of the critical zone. In addition to considering Earth and climate boundary conditions, these sites incorporate the roles that humans play in driving critical zone processes. For instance along the edges of KNP there is strong evidence of soil erosions due to periurbanization and small-scale agriculture. The existence of KNP provides an important contrast between a "natural" and "human-dominated" landscape that can be exploited to evaluate human impacts on critical zone resources and to develop targeted mitigation strategies. Western Australia has an exploitive economy that relies on large-scale agriculture and mineral extraction, both are intensive users of water which is scarce. The proposed CZO there will be partly focused on managing water under intense economic pressures. It is evident that if funding can be found for these sites they will enhance both critical zone science and practical applied science.

  20. Ius Chasma Tributary Valleys and Adjacent Plains

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This image covers valley tributaries of Ius Chasma, as well as the plains adjacent to the valleys. Ius Chasma is one of several canyons that make up the Valles Marineris canyon system. Valles Marineris likely formed by extension associated with the growth of the large volcanoes and topographic high of Tharsis to the northwest. As the ground was pulled apart, large and deep gaps resulted in the valleys seen in the top and bottom of this HiRISE image. Ice that was once in the ground could have also melted to create additional removal of material in the formation of the valleys. HiRISE is able to see the rocks along the walls of both these valleys and also impact craters in the image. Rock layers that appear lower down in elevation appear rougher and are shedding boulders. Near the top of the walls and also seen in patches along the smooth plains are brighter layers. These brighter layers are not shedding boulders so they must represent a different kind of rock formed in a different kind of environment than those further down the walls. Because they are highest in elevation, the bright layers are youngest in age. HiRISE is able to see dozens of the bright layers, which are perhaps only a meter in thickness. Darker sand dunes and ripples cover most of the plains and fill the floors of impact craters.

    Image PSP_001351_1715 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on November 9, 2006. The complete image is centered at -8.3 degrees latitude, 275.4 degrees East longitude. The range to the target site was 254.3 km (158.9 miles). At this distance the image scale ranges from 25.4 cm/pixel (with 1 x 1 binning) to 101.8 cm/pixel (with 4 x 4 binning). The image shown here has been map-projected to 25 cm/pixel and north is up. The image was taken at a local Mars time of 3:32 PM and the scene is illuminated from the west with a solar incidence angle of 59 degrees, thus the sun was about

  1. Sound insulation property of membrane-type acoustic metamaterials carrying different masses at adjacent cells

    NASA Astrophysics Data System (ADS)

    Zhang, Yuguang; Wen, Jihong; Zhao, Honggang; Yu, Dianlong; Cai, Li; Wen, Xisen

    2013-08-01

    We present the experimental realization and theoretical understanding of membrane-type acoustic metamaterials embedded with different masses at adjacent cells, capable of increasing the transmission loss at low frequency. Owing to the reverse vibration of adjacent cells, Transmission loss (TL) peaks appear, and the magnitudes of the TL peaks exceed the predicted results of the composite wall. Compared with commonly used configuration, i.e., all cells carrying with identical mass, the nonuniformity of attaching masses causes another much low TL peak. Finite element analysis was employed to validate and provide insights into the TL behavior of the structure.

  2. Correlations between critical current density, j(sub c), critical temperature, T(sub c),and structural quality of Y1B2Cu3O(7-x) thin superconducting films

    NASA Astrophysics Data System (ADS)

    Chrzanowski, J.; Xing, W. B.; Atlan, D.; Irwin, J. C.; Heinrich, B.; Cragg, R. A.; Zhou, H.; Angus, V.; Habib, F.; Fife, A. A.

    1995-04-01

    Correlations between critical current density (j(sub c)) critical temperature (T(sub c)) and the density of edge dislocations and nonuniform strain have been observed in YBCO thin films deposited by pulsed laser ablation on (001) LaAlO3 single crystals. Distinct maxima in j(sub c) as a function of the linewidths of the (00 l) Bragg reflections and as a function of the mosaic spread have been found in the epitaxial films. These maxima in j(sub c) indicate that the magnetic flux lines, in films of structural quality approachingthat of single crystals, are insufficiently pinned which results in a decreased critical current density. T(sub c) increased monotonically with improving crystalline quality and approached a value characteristic of a pure single crystal. A strong correlation between j(sub c) and the density of edge dislocations ND was found. At the maximum of the critical current density the density of edge dislocations was estimated to be N(sub D) approximately 1-2 x 10(exp 9)/sq cm.

  3. Correlations between critical current density, j{sub c}, critical temperature, T{sub c}, and structural quality of Y{sub 1}B{sub 2}Cu{sub 3}O{sub 7-x} thin superconducting films

    SciTech Connect

    Chrzanowski, J.; Xing, W.B.; Atlan, D.

    1994-12-31

    Correlations between critical current density (j{sub c}) critical temperature (T{sub c}) and the density of edge dislocations and nonuniform strain have been observed in YBCO thin films deposited by pulsed laser ablation on (001) LaAlO{sub 3} single crystals. Distinct maxima in j{sub c} as a function of the linewidths of the (00{ell}) Bragg reflections and as a function of the mosaic spread have been found in the epitaxial films. These maxima in j{sub c} indicate that the magnetic flux lines, in films of structural quality approaching that of single crystals, are insufficiently pinned which results in a decreased critical current density. T{sub c} increased monotonically with improving crystalline quality and approached a value characteristic of a pure single crystal. A strong correlation between j{sub c} and the density of edge dislocations N{sub D} was found. At the maximum of the critical current density the density of edge dislocations was estimated to be N{sub D}{approximately}1-2 x 10{sup 9}/cm{sup 2}.

  4. Correlations between critical current density, j(sub c), critical temperature, T(sub c),and structural quality of Y1B2Cu3O(7-x) thin superconducting films

    NASA Technical Reports Server (NTRS)

    Chrzanowski, J.; Xing, W. B.; Atlan, D.; Irwin, J. C.; Heinrich, B.; Cragg, R. A.; Zhou, H.; Angus, V.; Habib, F.; Fife, A. A.

    1995-01-01

    Correlations between critical current density (j(sub c)) critical temperature (T(sub c)) and the density of edge dislocations and nonuniform strain have been observed in YBCO thin films deposited by pulsed laser ablation on (001) LaAlO3 single crystals. Distinct maxima in j(sub c) as a function of the linewidths of the (00 l) Bragg reflections and as a function of the mosaic spread have been found in the epitaxial films. These maxima in j(sub c) indicate that the magnetic flux lines, in films of structural quality approachingthat of single crystals, are insufficiently pinned which results in a decreased critical current density. T(sub c) increased monotonically with improving crystalline quality and approached a value characteristic of a pure single crystal. A strong correlation between j(sub c) and the density of edge dislocations ND was found. At the maximum of the critical current density the density of edge dislocations was estimated to be N(sub D) approximately 1-2 x 10(exp 9)/sq cm.

  5. The Thermomagnetic Instability in Superconducting Films with Adjacent Metal Layer

    NASA Astrophysics Data System (ADS)

    Vestgården, J. I.; Galperin, Y. M.; Johansen, T. H.

    2013-12-01

    Dendritic flux avalanches is a frequently encountered consequence of the thermomagnetic instability in type-II superconducting films. The avalanches, which are potentially harmful for superconductor-based devices, can be suppressed by an adjacent normal metal layer, even when the two layers are not in thermal contact. The suppression of the avalanches in this case is due to so-called magnetic braking, caused by eddy currents generated in the metal layer by propagating magnetic flux. We develop a theory of magnetic braking by analyzing coupled electrodynamics and heat flow in a superconductor-normal metal bilayer. The equations are solved by linearization and by numerical simulation of the avalanche dynamics. We find that in an uncoated superconductor, even a uniform thermomagnetic instability can develop into a dendritic flux avalanche. The mechanism is that a small non-uniformity caused by the electromagnetic non-locality induces a flux-flow hot spot at a random position. The hot spot quickly develops into a finger, which at high speeds penetrates into the superconductor, forming a branching structure. Magnetic braking slows the avalanches, and if the normal metal conductivity is sufficiently high, it can suppress the formation of the dendritic structure. During avalanches, the braking by the normal metal layer prevents the temperature from exceeding the transition temperature of the superconductor. Analytical criteria for the instability threshold are developed using the linear stability analysis. The criteria are found to match quantitatively the instability onsets obtained in simulations.

  6. View of north side from exterior stairs of adjacent building, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of north side from exterior stairs of adjacent building, bottom cut off by fringed buildings, view facing south-southwest - U.S. Naval Base, Pearl Harbor, Industrial X-Ray Building, Off Sixth Street, adjacent to and south of Facility No. 11, Pearl City, Honolulu County, HI

  7. Learning Non-Adjacent Regularities at Age 0 ; 7

    ERIC Educational Resources Information Center

    Gervain, Judit; Werker, Janet F.

    2013-01-01

    One important mechanism suggested to underlie the acquisition of grammar is rule learning. Indeed, infants aged 0 ; 7 are able to learn rules based on simple identity relations (adjacent repetitions, ABB: "wo fe fe" and non-adjacent repetitions, ABA: "wo fe wo", respectively; Marcus et al., 1999). One unexplored issue is…

  8. Delayed Acquisition of Non-Adjacent Vocalic Distributional Regularities

    ERIC Educational Resources Information Center

    Gonzalez-Gomez, Nayeli; Nazzi, Thierry

    2016-01-01

    The ability to compute non-adjacent regularities is key in the acquisition of a new language. In the domain of phonology/phonotactics, sensitivity to non-adjacent regularities between consonants has been found to appear between 7 and 10 months. The present study focuses on the emergence of a posterior-anterior (PA) bias, a regularity involving two…

  9. Structural insights into the mechanism of four-coordinate Cob(II)alamin formation in the active site of the Salmonella enterica ATP:Co(I)rrinoid adenosyltransferase enzyme: critical role of residues Phe91 and Trp93.

    PubMed

    Moore, Theodore C; Newmister, Sean A; Rayment, Ivan; Escalante-Semerena, Jorge C

    2012-12-01

    ATP:co(I)rrinoid adenosyltransferases (ACATs) are enzymes that catalyze the formation of adenosylcobalamin (AdoCbl, coenzyme B(12)) from cobalamin and ATP. There are three families of ACATs, namely, CobA, EutT, and PduO. In Salmonella enterica, CobA is the housekeeping enzyme that is required for de novo AdoCbl synthesis and for salvaging incomplete precursors and cobalamin from the environment. Here, we report the crystal structure of CobA in complex with ATP, four-coordinate cobalamin, and five-coordinate cobalamin. This provides the first crystallographic evidence of the existence of cob(II)alamin in the active site of CobA. The structure suggests a mechanism in which the enzyme adopts a closed conformation and two residues, Phe91 and Trp93, displace 5,6-dimethylbenzimidazole, the lower nucleotide ligand base of cobalamin, to generate a transient four-coordinate cobalamin, which is critical in the formation of the AdoCbl Co-C bond. In vivo and in vitro mutational analyses of Phe91 and Trp93 emphasize the important role of bulky hydrophobic side chains in the active site. The proposed manner in which CobA increases the redox potential of the cob(II)alamin/cob(I)alamin couple to facilitate formation of the Co-C bond appears to be analogous to that utilized by the PduO-type ACATs, where in both cases the polar coordination of the lower ligand to the cobalt ion is eliminated by placing that face of the corrin ring adjacent to a cluster of bulky hydrophobic side chains. PMID:23148601

  10. Species-level view of population structure and gene flow for a critically endangered primate (Varecia variegata)

    PubMed Central

    Baden, Andrea L; Holmes, Sheila M; Johnson, Steig E; Engberg, Shannon E; Louis, Edward E; Bradley, Brenda J

    2014-01-01

    Lemurs are among the world's most threatened mammals. The critically endangered black-and-white ruffed lemur (Varecia variegata), in particular, has recently experienced rapid population declines due to habitat loss, ecological sensitivities to habitat degradation, and extensive human hunting pressure. Despite this, a recent study indicates that ruffed lemurs retain among the highest levels of genetic diversity for primates. Identifying how this diversity is apportioned and whether gene flow is maintained among remnant populations will help to diagnose and target conservation priorities. We sampled 209 individuals from 19 sites throughout the remaining V. variegata range. We used 10 polymorphic microsatellite loci and ∼550 bp of mtDNA sequence data to evaluate genetic structure and population dynamics, including dispersal patterns and recent population declines. Bayesian cluster analyses identified two distinct genetic clusters, which optimally partitioned data into populations occurring on either side of the Mangoro River. Localities north of the Mangoro were characterized by greater genetic diversity, greater gene flow (lower genetic differentiation) and higher mtDNA haplotype and nucleotide diversity than those in the south. Despite this, genetic differentiation across all sites was high, as indicated by high average FST (0.247) and ΦST (0.544), and followed a pattern of isolation-by-distance. We use these results to suggest future conservation strategies that include an effort to maintain genetic diversity in the north and restore connectivity in the south. We also note the discordance between patterns of genetic differentiation and current subspecies taxonomy, and encourage a re-evaluation of conservation management units moving forward. PMID:25077019

  11. Critical Structural and Functional Roles for the N-Terminal Insertion Sequence in Surfactant Protein B Analogs

    PubMed Central

    Walther, Frans J.; Waring, Alan J.; Hernandez-Juviel, Jose M.; Gordon, Larry M.; Wang, Zhengdong; Jung, Chun-Ling; Ruchala, Piotr; Clark, Andrew P.; Smith, Wesley M.; Sharma, Shantanu; Notter, Robert H.

    2010-01-01

    Background Surfactant protein B (SP-B; 79 residues) belongs to the saposin protein superfamily, and plays functional roles in lung surfactant. The disulfide cross-linked, N- and C-terminal domains of SP-B have been theoretically predicted to fold as charged, amphipathic helices, suggesting their participation in surfactant activities. Earlier structural studies with Mini-B, a disulfide-linked construct based on the N- and C-terminal regions of SP-B (i.e., ∼residues 8–25 and 63–78), confirmed that these neighboring domains are helical; moreover, Mini-B retains critical in vitro and in vivo surfactant functions of the native protein. Here, we perform similar analyses on a Super Mini-B construct that has native SP-B residues (1–7) attached to the N-terminus of Mini-B, to test whether the N-terminal sequence is also involved in surfactant activity. Methodology/Results FTIR spectra of Mini-B and Super Mini-B in either lipids or lipid-mimics indicated that these peptides share similar conformations, with primary α-helix and secondary β-sheet and loop-turns. Gel electrophoresis demonstrated that Super Mini-B was dimeric in SDS detergent-polyacrylamide, while Mini-B was monomeric. Surface plasmon resonance (SPR), predictive aggregation algorithms, and molecular dynamics (MD) and docking simulations further suggested a preliminary model for dimeric Super Mini-B, in which monomers self-associate to form a dimer peptide with a “saposin-like” fold. Similar to native SP-B, both Mini-B and Super Mini-B exhibit in vitro activity with spread films showing near-zero minimum surface tension during cycling using captive bubble surfactometry. In vivo, Super Mini-B demonstrates oxygenation and dynamic compliance that are greater than Mini-B and compare favorably to full-length SP-B. Conclusion Super Mini-B shows enhanced surfactant activity, probably due to the self-assembly of monomer peptide into dimer Super Mini-B that mimics the functions and putative structure of

  12. Magnetic transition from the paramagnetic to long-period structure in RMn{sub 2}O{sub 5} multiferroics: Renormalization group analysis of critical behavior

    SciTech Connect

    Men'shenin, V. V.

    2013-06-15

    A transition from the paramagnetic state to a long-period magnetic structure with an incommensurate wave vector along one crystallographic axis in RMn{sub 2}O{sub 5} multiferroics is considered. An effective Hamiltonian for these oxides is constructed with allowance for spin fluctuations. Critical points are found, and their stability is analyzed using the renormalization group approach. It is shown that critical fluctuations in these compounds admit a second-order phase transition with respect to a multicomponent order parameter.

  13. Response of a continuous anaerobic digester to temperature transitions: A critical range for restructuring the microbial community structure and function.

    PubMed

    Kim, Jaai; Lee, Changsoo

    2016-02-01

    Temperature is a crucial factor that significantly influences the microbial activity and so the methanation performance of an anaerobic digestion (AD) process. Therefore, how to control the operating temperature for optimal activity of the microbes involved is a key to stable AD. This study examined the response of a continuous anaerobic reactor to a series of temperature shifts over a wide range of 35-65 °C using a dairy-processing byproduct as model wastewater. During the long-term experiment for approximately 16 months, the reactor was subjected to stepwise temperature increases by 5 °C at a fixed HRT of 15 days. The reactor showed stable performance within the temperature range of 35-45 °C, with the methane production rate and yield being maximum at 45 °C (18% and 26% greater, respectively, than at 35 °C). However, the subsequent increase to 50 °C induced a sudden performance deterioration with a complete cessation of methane recovery, indicating that the temperature range between 45 °C and 50 °C had a critical impact on the transition of the reactor's methanogenic activity from mesophilic to thermophilic. This serious process perturbation was associated with a severe restructuring of the reactor microbial community structure, particularly of methanogens, quantitatively as well as qualitatively. Once restored by interrupted feeding for about two months, the reactor maintained fairly stable performance under thermophilic conditions until it was upset again at 65 °C. Interestingly, in contrast to most previous reports, hydrogenotrophs largely dominated the methanogen community at mesophilic temperatures while acetotrophs emerged as a major group at thermophilic temperature. This implies that the primary methanogenesis route of the reactor shifted from hydrogen- to acetate-utilizing pathways with the temperature shifts from mesophilic to thermophilic temperatures. Our observations suggest that a mesophilic digester may not need to be cooled at up

  14. Thermoelastic response of thin metal films and their adjacent materials

    SciTech Connect

    Kang, S.; Yoon, Y.; Kim, J.; Kim, W.

    2013-01-14

    A pulsed laser beam applied to a thin metal film is capable of launching an acoustic wave due to thermal expansion. Heat transfer from the thin metal film to adjacent materials can also induce thermal expansion; thus, the properties of these adjacent materials (as well as the thin metal film) should be considered for a complete description of the thermoelastic response. Here, we show that adjacent materials with a small specific heat and large thermal expansion coefficient can generate an enhanced acoustic wave and we demonstrate a three-fold increase in the peak pressure of the generated acoustic wave on substitution of parylene for polydimethylsiloxane.

  15. Ambient Pressure Structural Quantum Critical Point in the Phase Diagram of (CaxSr1-x)3Rh4Sn13

    NASA Astrophysics Data System (ADS)

    Goh, Swee K.; Tompsett, D. A.; Saines, P. J.; Chang, H. C.; Matsumoto, T.; Imai, M.; Yoshimura, K.; Grosche, F. M.

    The quasiskutterudite superconductor Sr3Rh4Sn13 features a pronounced anomaly in electrical resistivity at T* ~ 138 K. The anomaly is caused by a second-order structural transition, which can be tuned to 0 K by applying physical pressure and chemical pressure via the substitution of Ca for Sr. A broad superconducting dome is centered around the structural quantum critical point. Detailed analysis of the tuning parameter dependence of T* as well as insights from lattice dynamics calculations strongly support the existence of a structural quantum critical point at ambient pressure when the fraction of Ca is 0.9 (xc=0.9). This establishes the (CaxSr1-x)3Rh4Sn13 series as an important system for exploring the physics of structural quantum criticality and its interplay with the superconductivity, without the need of applying high pressures. This work was supported by CUHK (Startup Grant, Direct Grant No. 4053071), UGC Hong Kong (ECS/24300214), Trinity College (Cam- bridge), Grants-in-Aid from MEXT (No. 22350029 and 23550152) and Glasstone Bequest (Oxford).

  16. The speciation of marine particulate iron adjacent to active and passive continental margins

    NASA Astrophysics Data System (ADS)

    Lam, Phoebe J.; Ohnemus, Daniel C.; Marcus, Matthew A.

    2012-03-01

    We use synchrotron-based chemical-species mapping techniques to compare the speciation of suspended (1-51 μm) marine particulate iron collected in two open ocean environments adjacent to active and passive continental margins. Chemical-species mapping provides speciation information for heterogeneous environmental samples, and is especially good for detecting spectroscopically distinct trace minerals and species that could not be detectable by other methods. The average oxidation state of marine particulate iron determined by chemical-species mapping is comparable to that determined by standard bulk X-ray Absorption Near Edge Structure spectroscopy. Using chemical-species mapping, we find that up to 43% of particulate Fe in the Northwest Pacific at the depth of the adjacent active continental margin is in the Fe(II) state, with the balance Fe(III). In contrast, particulate iron in the eastern tropical North Atlantic, which receives the highest dust deposition on Earth and is adjacent to a passive margin, is dominated by weathered and oxidized Fe compounds, with Fe(III) contributing 90% of total iron. The balance is composed primarily of Fe(II)-containing species, but we detected individual pyrite particles in some samples within an oxygen minimum zone in the upper thermocline. Several lines of evidence point to the adjacent Mauritanian continental shelf as the source of pyrite to the water column. The speciation of suspended marine particulate iron reflects the mineralogy of iron from the adjacent continental margins. Since the solubility of particulate iron has been shown to be a function of its speciation, this may have implications for the bioavailability of particulate iron adjacent to passive compared to active continental margins.

  17. 73. PASSAGE ADJACENT TO ROOM 232, EAST WING, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. PASSAGE ADJACENT TO ROOM 232, EAST WING, SECOND FLOOR, LOOKING WEST BY NORTHWEST, SHOWING EASTERNMOST ARCH OF FORMER GREAT HALL NORTH ARCADE - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  18. View of viaduct, looking SE from roof of adjacent parking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of viaduct, looking SE from roof of adjacent parking garage. - Mulberry Street Viaduct, Spanning Paxton Creek & Cameron Street (State Route 230) at Mulberry Street (State Route 3012), Harrisburg, Dauphin County, PA

  19. Cement Leakage into Adjacent Vertebral Body Following Percutaneous Vertebroplasty

    PubMed Central

    Park, Jae Hoo; Kim, Hyeun Sung

    2016-01-01

    Percutaneous vertebroplasty (PV) is a minimally invasive procedure for osteoporotic vertebral compression fractures that fail to respond to conventional conservative treatment. It significantly improves intolerable back pain within hours, and has a low complication rate. Although rare, PV is not free of complications, most of which are directly related to cement leakage. Because of its association with new adjacent fracture, the importance of cement leakage into the adjacent disc space is paramount. Here, we report an interesting case of cement leakage into the adjacent upper vertebral body as well as disc space following PV. To the best of our knowledge, there has been no report of cement leakage into the adjacent vertebral body following PV. This rare case is presented along with a review of the literature. PMID:27437018

  20. 1. HEBRONVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR. HEBRONVILLE, BRISTOL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. HEBRONVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR. HEBRONVILLE, BRISTOL CO., MA. Sec. 4116, MP 193.75. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

  1. 3. DODGEVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR DODGEVILLE, BRISTOL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. DODGEVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR DODGEVILLE, BRISTOL CO., MA. Sec. 4116, MP 195.55. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

  2. 33. HISTORIC PLAQUE MARKING WHERE JOHNSTON DIED, ADJACENT TO PATHWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. HISTORIC PLAQUE MARKING WHERE JOHNSTON DIED, ADJACENT TO PATHWAY WITH CONCRETE CULVERT LEADING NORTH OUT OF RAVINE TOWARD JOHNSTON MEMORIAL SITE. VIEW NW. - Shiloh National Military Park Tour Roads, Shiloh, Hardin County, TN

  3. Lock 4 View east of lock wall and adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Lock 4 - View east of lock wall and adjacent roadway built atop tow path. The gate pocket can be seen at center. - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

  4. 1. Ninth Street (west) facade. Adjacent on the north is ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Ninth Street (west) facade. Adjacent on the north is the 9th Street facade of 816 E Street. Both buildings were originally one property. - Riley Building, Rendezvous Adult Magazines & Films, 437 Ninth Street, Northwest, Washington, District of Columbia, DC

  5. 2. THREEQUARTER VIEW FROM ADJACENT ACCESS ROAD SHOWING THREE SPANS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. THREE-QUARTER VIEW FROM ADJACENT ACCESS ROAD SHOWING THREE SPANS AND NORTHWEST APPROACH SPANS, LOOKING SOUTHEAST - Red River Bridge, Spanning Red River at U.S. Highway 82, Garland, Miller County, AR

  6. 1. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING SOUTH. GARAGE TO EXTREME LEFT, BUILDING 1 TO EXTREME RIGHT. - Techwood Homes (Public Housing), Bounded by North Avenue, Parker Street, William Street & Lovejoy Street, Atlanta, Fulton County, GA

  7. 3. View of north side of house facing from adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of north side of house facing from adjacent vacant property. Original wood lap siding and trim is covered by aluminum siding. Recessed side porch is in middle. - 645 South Eighteenth Street (House), Louisville, Jefferson County, KY

  8. 1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE OF THE ADIT OPENINGS (VIEW TO THE NORTH). - Foster Gulch Mine, Fan Housing, Bear Creek 1 mile Southwest of Town of Bear Creek, Red Lodge, Carbon County, MT

  9. 7. August, 1970 9 ORANGE STREET, ADJACENT TO UNITARIAN CHURCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. August, 1970 9 ORANGE STREET, ADJACENT TO UNITARIAN CHURCH (NOT IN STUDY AREA) - Orange & Union Streets Neighborhood Study, 8-31 Orange Street, 9-21 Union Street & Stone Alley, Nantucket, Nantucket County, MA

  10. OBLIQUE OF SOUTHWEST END AND SOUTHEAST SIDE, WITH ADJACENT FACILITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OBLIQUE OF SOUTHWEST END AND SOUTHEAST SIDE, WITH ADJACENT FACILITY 391 IN THE FOREGROUND. - U.S. Naval Base, Pearl Harbor, Joint Intelligence Center, Makalapa Drive in Makalapa Administration Area, Pearl City, Honolulu County, HI

  11. Complications in exodontia--accidental dislodgment to adjacent anatomical areas.

    PubMed

    Grandini, S A; Barros, V M; Salata, L A; Rosa, A L; Soares, U N

    1993-01-01

    The authors report 4 cases of accidental dislodgement of teeth to adjacent anatomical areas during extraction. The causes and their prevention are discussed and solutions for the problem are suggested. PMID:8241759

  12. 6. Detail, vertical guides adjacent to east portal of Tunnel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail, vertical guides adjacent to east portal of Tunnel 28, view to southwest, 135mm lens with electronic flash fill. - Central Pacific Transcontinental Railroad, Tunnel No. 28, Milepost 134.75, Applegate, Placer County, CA

  13. VIEW OF CONSTRUCTION CAMP ROCK FEATURE WITH OVER, ADJACENT TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF CONSTRUCTION CAMP ROCK FEATURE WITH OVER, ADJACENT TO THE COLUMBIA SOUTHERN CANAL. LOOKING NORTHWEST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

  14. Pump house adjacent to the superintendent's house at the west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Pump house adjacent to the superintendent's house at the west end of the complex near Highway 101. Detail of Holloshaft pump. View to the south. - Prairie Creek Fish Hatchery, Hwy. 101, Orick, Humboldt County, CA

  15. VIEW OF NORTHERN AND EASTERN SIDES FROM PARKING LOT ADJACENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF NORTHERN AND EASTERN SIDES FROM PARKING LOT ADJACENT TO BUILDING 199 (POLICE STATION) - U.S. Naval Base, Pearl Harbor, Post Office, Avenue A near Eleventh Avenue, Pearl City, Honolulu County, HI

  16. 24. INTERIOR VIEW, WILLIAM GRAY AT SIZING GUAGE ADJACENT TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. INTERIOR VIEW, WILLIAM GRAY AT SIZING GUAGE ADJACENT TO BRADLEY HAMMER; NOTE THIS IS THE SAME TOOL AS BEING FORGED ABOVE - Warwood Tool Company, Foot of Nineteenth Street, Wheeling, Ohio County, WV

  17. Detail exterior view looking north showing piping system adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail exterior view looking north showing piping system adjacent to engine house. Gas cooling system is on far right. - Burnsville Natural Gas Pumping Station, Saratoga Avenue between Little Kanawha River & C&O Railroad line, Burnsville, Braxton County, WV

  18. VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST CORNER OF BUILDING 23, FACING NORTH - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

  19. 14. Charles Acey Cobb standing adjacent to the fish screen ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Charles Acey Cobb standing adjacent to the fish screen he designed and installed in the Congdon Canal, facing southeast. Photo dates ca. late 1920's. - Congdon Canal, Fish Screen, Naches River, Yakima, Yakima County, WA

  20. 52. EASTSIDE PLANT: GENERAL VIEW OF GOVERNOR ADJACENT TO GENERATOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. EASTSIDE PLANT: GENERAL VIEW OF GOVERNOR ADJACENT TO GENERATOR - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  1. Interior building details of Building A, dungeon cell adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior building details of Building A, dungeon cell adjacent to northwest cell: granite and brick threshold, poured concrete floors, plastered finished walls, vaulted veiling; northwesterly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  2. Rayleigh wave tomography of China and adjacent regions

    NASA Astrophysics Data System (ADS)

    Huang, Zhongxian; Su, Wei; Peng, Yanju; Zheng, Yuejun; Li, Hongyi

    2003-02-01

    This paper presents a tomographic study on the S wave velocity structure of China and adjacent regions. Group velocity dispersions of fundamental Rayleigh waves along more than 4000 paths were determined with frequency-time analysis. The study region was divided into a 1° × 1° grid, and velocities in between grid nodes were calculated by bilinear interpolation. The Occam's inversion scheme was adopted to invert for group velocity distributions. This method is robust and allows us to use a fine grid in model parameterization and thus helps to restore a more realistic velocity pattern. Checkerboard tests were carried out, and the lateral resolution was estimated to be 4°-6° in China and its eastern continental shelves. The resulting group velocity maps from 10 to 184 s showed good correlation with known geological and tectonic features. The pure path dispersion curves at each node were inverted for shear wave velocity structures. The three-dimensional velocity model indicates thick lithospheres in the Yangtze and Tarim platforms and hot upper mantles in Baikal and western Mongolia, coastal area and continental shelves of eastern China, and Indochina and South China Sea regions. The Tibetan Plateau has a very thick crust with a low-velocity zone in its middle. Beneath the crust a north dipping high-velocity zone, mimicking a subducting plate, reaches to 200 km in depth and reaches to the Kunlun Mountains northward. In northern Tibet a low-velocity zone immediately below the Moho extends eastward then turns southward along the eastern edge of the plateau until it connects to the vast low-velocity area in Indochina and the South China Sea.

  3. Adjacent Segment Disease Perspective and Review of the Literature

    PubMed Central

    Saavedra-Pozo, Fanor M.; Deusdara, Renato A. M.; Benzel, Edward C.

    2014-01-01

    Background Adjacent segment disease has become a common topic in spine surgery circles because of the significant increase in fusion surgery in recent years and the development of motion preservation technologies that theoretically should lead to a decrease in this pathology. The purpose of this review is to organize the evidence available in the current literature on this subject. Methods For this literature review, a search was conducted in PubMed with the following keywords: adjacent segment degeneration and disease. Selection, review, and analysis of the literature were completed according to level of evidence. Results The PubMed search identified 850 articles, from which 41 articles were selected and reviewed. The incidence of adjacent segment disease in the cervical spine is close to 3% without a significant statistical difference between surgical techniques (fusion vs arthroplasty). Authors report the incidence of adjacent segment disease in the lumbar spine to range from 2% to 14%. Damage to the posterior ligamentous complex and sagittal imbalances are important risk factors for both degeneration and disease. Conclusion Insufficient evidence exists at this point to support the idea that total disc arthroplasty is superior to fusion procedures in minimizing the incidence of adjacent segment disease. The etiology is most likely multifactorial but it is becoming abundantly clear that adjacent segment disease is not caused by motion segment fusion alone. Fusion plus the presence of abnormal end-fusion alignment appears to be a major factor in creating end-fusion stresses that result in adjacent segment degeneration and subsequent disease. The data presented cast further doubt on previously established rationales for total disc arthroplasty, at least with regard to the effect of total disc arthroplasty on adjacent segment degeneration pathology. PMID:24688337

  4. Approximating the largest eigenvalue of network adjacency matrices

    NASA Astrophysics Data System (ADS)

    Restrepo, Juan G.; Ott, Edward; Hunt, Brian R.

    2007-11-01

    The largest eigenvalue of the adjacency matrix of a network plays an important role in several network processes (e.g., synchronization of oscillators, percolation on directed networks, and linear stability of equilibria of network coupled systems). In this paper we develop approximations to the largest eigenvalue of adjacency matrices and discuss the relationships between these approximations. Numerical experiments on simulated networks are used to test our results.

  5. Critical Thinking.

    ERIC Educational Resources Information Center

    Callison, Daniel

    1998-01-01

    Distinguishes between critical and creative thinking and discusses critical-thinking in relation to modern instructional programs and information literacy. Outlines goals in critical-thinking curriculum, critical thinking skills (student disposition, interpretation, analysis, evaluation, inference, presenting argument, and reflection), and…

  6. Strong Coupling Superconductivity in the Vicinity of the Structural Quantum Critical Point in (CaxSr1-x)3Rh4Sn13

    NASA Astrophysics Data System (ADS)

    Yu, Wing Chi; Cheung, Yiu Wing; Saines, Paul J.; Imai, Masaki; Matsumoto, Takuya; Michioka, Chishiro; Yoshimura, Kazuyoshi; Goh, Swee K.

    The family of the superconducting quasiskutterudites (CaxSr1-x)3Rh4Sn13 features a structural quantum critical point at xc = 0 . 9 , around which a dome-shaped variation of the superconducting transition temperature Tc is found. In this talk, we present the specific heat data for the normal and the superconducting states of the entire series straddling the quantum critical point. Our analysis indicates a significant lowering of the effective Debye temperature on approaching xc, which we interpret as a result of phonon softening accompanying the structural instability. Furthermore, a remarkably large enhancement of 2 Δ /kBTc and ΔC / γTc beyond the Bardeen-Cooper-Schrieffer values is found in the vicinity of the structural quantum critical point. Reference: Wing Chi Yu et al. Phys. Rev. Lett. (in press, 2015) This work was supported by the CUHK (Startup Grant, Direct Grant No. 4053071), UGC Hong Kong (ECS/24300214), Grants-in-Aid from MEXT (22350029 and 23550152), and Glasstone Bequest, Oxford.

  7. Management of the aging of critical safety-related concrete structures in light-water reactor plants

    SciTech Connect

    Naus, D.J.; Oland, C.B. ); Arndt, E.G. )

    1990-01-01

    The Structural Aging Program has the overall objective of providing the USNRC with an improved basis for evaluating nuclear power plant safety-related structures for continued service. The program consists of a management task and three technical tasks: materials property data base, structural component assessment/repair technology, and quantitative methodology for continued-service determinations. Objectives, accomplishments, and planned activities under each of these tasks are presented. Major program accomplishments include development of a materials property data base for structural materials as well as an aging assessment methodology for concrete structures in nuclear power plants. Furthermore, a review and assessment of inservice inspection techniques for concrete materials and structures has been complete, and work on development of a methodology which can be used for performing current as well as reliability-based future condition assessment of concrete structures is well under way. 43 refs., 3 tabs.

  8. T.H. Huxley's criticism of German cell theory: an epigenetic and physiological interpretation of cell structure.

    PubMed

    Richmond, M L

    2000-01-01

    In 1853, the young Thomas Henry Huxley published a long review of German cell theory in which he roundly criticized the basic tenets of the Schleiden-Schwann model of the cell. Although historians of cytology have dismissed Huxley's criticism as based on an erroneous interpretation of cell physiology, the review is better understood as a contribution to embryology. "The Cell-theory" presents Huxley's "epigenetic" interpretation of histological organization emerging from changes in the protoplasm to replace the "preformationist" cell theory of Schleiden and Schwann (as modified by Albert von Kolliker), which posited the nucleus as the seat of organic vitality. Huxley's views influenced a number of British biologists, who continued to oppose German cell theory well into the twentieth century. Yet Huxley was pivotal in introducing the new German program of "scientific zoology" to Britain in the early 1850s, championing its empiricist methodology as a means to enact broad disciplinary and institutional reforms in British natural history. PMID:11640226

  9. Investigation on critical structural motifs of ligands for triggering glucocorticoid receptor nuclear migration through molecular docking simulations.

    PubMed

    Liu, Ya-Lin; Jang, Soonmin; Wang, Shih-Min; Chen, Chiu-Hao; Li, Feng-Yin

    2016-06-01

    The glucocorticoid receptor (GR), a transcription factor regulating gene expression in a ligand-dependent fashion, is known for flexibility in adapting various ligands with their structures ranging from steroid to non-steroid. However, in our previous study, GR shows a stringent discrimination against a set of steroid ligands with highly similar structures for triggering its nuclear migration. In order to resolve this puzzle, we employed molecular docking simulations to investigate the origin of this structural discrimination. By analyzing the docking orientations and the related ligand-GR interaction patterns, we found that the hydrophilicity mismatch between the docking ligand and the GR ligand-binding site is the main cause combined with the steric hindrance and structural rigidness of these steroid ligands. Furthermore, we utilized this knowledge to rationalize how the structure-binding interaction of non-steroid ligands triggers GR nuclear migration with their structures available in Protein Data Bank. PMID:26198481

  10. Challenges and Potential Solutions – Individualised Antibiotic Dosing at the Bedside for Critically Ill Patients: a structured review

    PubMed Central

    Roberts, Jason A.; Aziz, Mohd Hafiz Abdul; Lipman, Jeffrey; Mouton, Johan W.; Vinks, Alexander A.; Felton, Timothy W.; Hope, William W.; Farkas, Andras; Neely, Michael N.; Schentag, Jerome J.; Drusano, George; Frey, Otto R.; Theuretzbacher, Ursula; Kuti, Joseph L.

    2014-01-01

    Summary Infections in critically ill patients are associated with persistently poor clinical outcomes. These patients have severely altered and variable antibiotic pharmacokinetics and are infected by less susceptible pathogens. Antibiotic dosing that does not account for these features is likely to result in sub-optimal outcomes. In this paper, we review the patient- and pathogen-related challenges that contribute to inadequate antibiotic dosing and discuss how a process for individualised antibiotic therapy, that increases the accuracy of dosing, can be implemented to further optimise care for the critically ill patient. The process for optimised antibiotic dosing firstly requires determination of the physiological derangements in the patient that can alter antibiotic concentrations including altered fluid status, microvascular failure, serum albumin concentrations as well as altered renal and hepatic function. Secondly, knowledge of the susceptibility of the infecting pathogen should be determined through liaison with the microbiology laboratory. The patient and pathogen challenges can then be solved by combining susceptibility data with measured antibiotic concentration data (where possible) into a clinical dosing software. Such software uses pharmacokinetic-pharmacodynamic (PK/PD) models from critically ill patients to accurately predict the dosing requirements for the individual patient with the aim of optimising antibiotic exposure and maximising effectiveness. PMID:24768475

  11. Thinking Critically about Critical Thinking

    ERIC Educational Resources Information Center

    Mulnix, Jennifer Wilson

    2012-01-01

    As a philosophy professor, one of my central goals is to teach students to think critically. However, one difficulty with determining whether critical thinking can be taught, or even measured, is that there is widespread disagreement over what critical thinking actually is. Here, I reflect on several conceptions of critical thinking, subjecting…

  12. A critical analysis of air shower structure functions and size spectrum measurements with the NBU air shower array

    NASA Technical Reports Server (NTRS)

    Chaudhuri, N.; Basak, D. K.

    1985-01-01

    A total of 11,000 showers in the size range 10 to the 4 to 10 to the 6 particles so far detected by the NBU air shower array has been analyzed using five different structure functions. A comparison of structure functions in terms: (1) of shower size; and (2) electron density at various core distances has been discussed to indicate the present status of structure functions in air shower analysis.

  13. Seismotectonics of Northeastern United States and adjacent Canada

    SciTech Connect

    Yang, J.; Aggarwal, Y.P.

    1981-06-10

    Data for local earthquakes recorded by a network of stations in northeastern United States and adjacent Canada were analyzed to study the seismicity, the relationship between earthquakes and known faults, the state of stress, and crustal and upper mantle velocity structure. In addition, portable seismographs were deployed in the field to study aftershocks. As a result, accurate locations for about 364 local earthquakes (2< or =m/sub b/< or =5) and 22 focal mechanism solutions were determined. A comparison of the spatial distribution of these events (1970--1979) with historical earthquakes (1534--1959) reveals that seismic activity in the northeast is relatively stationary in space: those areas that have had little or no seismicity historically are relatively aseismic today, whereas the historically active areas are also active today. The instrumental locations, historical seismicity, and focal mechanism solutions show an internal consistency that help us distinguish two distinct seismogenic provinces. (1) The Adirondack-western Quebec province is a northwesterly trending zone of seismic activity, about 200 km wide and at least 500 km long, extending from the SE Adirondacks into western Quebec, Canada. Thrust faulting on planes striking NNW to NW appears to predominate, and the inferred axis of maximum horizontal compression is largely uniform and trends WSW, nearly parallel to the calculated absolute plate motion of North America. Little or no seismicity is found where anorthosite outcrops at the surface. Correlations between gravity anomalies and earthquake locations suggest that seismic activity in this zone is localized to regions of steep NE or SW gradient in Bouguer anomalies. This zone does not appear to extend southeastward to Boston, as proposed by some workers. (2) The Appalachian province is a northeasterly trending zone of seismic activity extending from northern Virginia to New Brunswick, Canada.

  14. Critical Initial Flaw Size Analysis

    NASA Technical Reports Server (NTRS)

    Dawicke, David S.; Raju, Ivatury S.; Cheston, Derrick J.

    2008-01-01

    An independent assessment was conducted to determine the critical initial flaw size (CIFS) for the flange-to-skin weld in the Ares I-X Upper Stage Simulator (USS). The USS consists of several "tuna can" segments that are approximately 216 inches in diameter, 115 inches tall, and 0.5 inches thick. A 6 inch wide by 1 inch thick flange is welded to the skin and is used to fasten adjacent tuna cans. A schematic of a "tuna can" and the location of the flange-to-skin weld are shown in Figure 1. Gussets (shown in yellow in Figure 1) are welded to the skin and flange every 10 degrees around the circumference of the "tuna can". The flange-to-skin weld is a flux core butt weld with a fillet weld on the inside surface, as illustrated in Figure 2. The welding process may create loss of fusion defects in the weld that could develop into fatigue cracks and jeopardize the structural integrity of the Ares I-X vehicle. The CIFS analysis was conducted to determine the largest crack in the weld region that will not grow to failure within 4 lifetimes, as specified by NASA standard 5001 & 5019 [1].

  15. Irreversible Electroporation of a Hepatocellular Carcinoma Lesion Adjacent to a Transjugular Intrahepatic Portosystemic Shunt Stent Graft

    PubMed Central

    Jung, Ernst Michael; Wohlgemuth, Walter A.; Trabold, Benedikt; Haimerl, Michael; Schreyer, Andreas; Stroszczynski, Christian; Wiggermann, Philipp

    2013-01-01

    We report in a 65-year-old man hepatocellular carcinoma adjacent to a transjugular intrahepatic portosystemic shunt stent-graft which was successfully treated with irreversible electroporation (IRE). IRE is a new non-thermal tissue ablation technique which uses electrical pulses to induce cell necrosis by irreversible membrane poration. IRE proved to be more advantageous in the ablation of perivascular tumor with little injury to the surrounding structures. PMID:24043975

  16. The Effects of High-Structure Cooperative versus Low-Structure Collaborative Design of Decision Change, Critical Thinking, and Interaction Pattern during Online Debates

    ERIC Educational Resources Information Center

    Joung, Sunyoung; Keller, John M.

    2004-01-01

    The terms "cooperative" and "collaborative" are sometimes used interchangeably in reference to group learning activities in classrooms and in online settings. However, they can be viewed as differing in terms of characteristics such as pre-structure, task structure, and content structure (Strijbos & Martens, 2001; Panitz, 1996). This study…

  17. Dimensional analysis of earthquake-induced pounding between adjacent inelastic MDOF buildings

    NASA Astrophysics Data System (ADS)

    Zhai, Changhai; Jiang, Shan; Li, Shuang; Xie, Lili

    2015-06-01

    In this study the seismic pounding response of adjacent multi-degree-of-freedom (MDOF) buildings with bilinear inter-story resistance characteristics is investigated through dimensional analysis. The application of dimensional analysis leads to a condensed presentation of the response, and the remarkable self-similarity property for bilinear MDOF buildings with inelastic collision is uncovered. It is shown that when the response is expressed in the appropriate dimensionless form, response spectra for any intensity of the excitation collapse to a single master curve. The reduced Π set explicitly describes the interaction between the colliding structures. The effect of pounding on the MDOF building's response is illustrated using three well-divided spectral regions (amplified, de-amplified and unaffected regions). Parametric studies are conducted to investigate the effects of the story stiffness of structures, the story stiffness ratio and mass ratio of adjacent buildings, the structural inelastic characteristics and the gap size values. Results show that (i) the influence of system stiffness ratio to the lighter and more flexible building is more significant in the first spectral region, where the maximum response of the building is amplified because of pounding; and (ii) the velocity and pounding force of the heavier and stiffer building is unexpectedly sensitive to the mass ratio of adjacent buildings.

  18. Lifetime measurements in 102Pd: Searching for empirical proof of the E(5) critical-point symmetry in nuclear structure

    NASA Astrophysics Data System (ADS)

    Konstantinopoulos, T.; Ashley, S. F.; Axiotis, M.; Spyrou, A.; Harissopulos, S.; Dewald, A.; Litzinger, J.; Möller, O.; Müller-Gatterman, C.; Petkov, P.; Napoli, D. R.; Marginean, N.; de Angelis, G.; Ur, C. A.; Bazzacco, D.; Farnea, E.; Lenzi, S. M.; Vlastou, R.; Balabanski, D.

    2016-01-01

    Lifetimes of yrast and nonyrast states of 102Pd populated via the 92Zr(13C, 3 n ) reaction are measured by means of the recoil distance Doppler-shift technique with a Cologne plunger coupled to a GASP spectrometer. The event-by-event data accumulated at 24 plunger distances in the range of 0.1 μ m to 9 mm are analyzed using the differential decay curve method. The resulting B (E 2 ) values of the γ transitions depopulating yrast-band members up to the Iπ=8+ state are found to deviate significantly from the corresponding predictions of the E(5) critical-point symmetry.

  19. Laplacian versus adjacency matrix in quantum walk search

    NASA Astrophysics Data System (ADS)

    Wong, Thomas G.; Tarrataca, Luís; Nahimov, Nikolay

    2016-06-01

    A quantum particle evolving by Schrödinger's equation contains, from the kinetic energy of the particle, a term in its Hamiltonian proportional to Laplace's operator. In discrete space, this is replaced by the discrete or graph Laplacian, which gives rise to a continuous-time quantum walk. Besides this natural definition, some quantum walk algorithms instead use the adjacency matrix to effect the walk. While this is equivalent to the Laplacian for regular graphs, it is different for non-regular graphs and is thus an inequivalent quantum walk. We algorithmically explore this distinction by analyzing search on the complete bipartite graph with multiple marked vertices, using both the Laplacian and adjacency matrix. The two walks differ qualitatively and quantitatively in their required jumping rate, runtime, sampling of marked vertices, and in what constitutes a natural initial state. Thus the choice of the Laplacian or adjacency matrix to effect the walk has important algorithmic consequences.

  20. Critical Care

    MedlinePlus

    Critical care helps people with life-threatening injuries and illnesses. It might treat problems such as complications from surgery, ... attention by a team of specially-trained health care providers. Critical care usually takes place in an ...

  1. Decoupling Contributions from Canopy Structure and Leaf Optics is Critical for Remote Sensing Leaf Biochemistry (Reply to Townsend, et al.)

    NASA Technical Reports Server (NTRS)

    Knyazikhin, Yuri; Lewis, Philip; Disney, Mathias I.; Stenberg, Pauline; Mottus, Matti; Rautianinen, Miina; Kaufmann, Robert K.; Marshak, Alexander; Schull, Mitchell A.; Carmona, Pedro Latorre; Vanderbilt, Vern; Davis, Anthony B.; Baret, Frederic; Jacquemoud, Stephane; Lyapustin, Alexei; Yang, Yan; Myneni, Ranga B.

    2013-01-01

    Townsend et al. (1) agree that we explained that the apparent relationship (2) between foliar nitrogen (%N) and near-infrared (NIR) canopy reflectance was largely attributable to structure (which is in turn caused by variation in fraction of broadleaf canopy). Our conclusion that the observed correlation with %N was spurious (i.e., lacking a causal basis) is, thus, clearly justified: we demonstrated that structure explained the great majority of observed correlation, where the structural influence was derived precisely via reconciling the observed correlation with radiative-transfer theory. What this also suggests is that such correlations, although observed, do not uniquely provide information on canopy biochemical constituents.

  2. On the Adjacent Eccentric Distance Sum Index of Graphs

    PubMed Central

    Qu, Hui; Cao, Shujuan

    2015-01-01

    For a given graph G, ε(v) and deg(v) denote the eccentricity and the degree of the vertex v in G, respectively. The adjacent eccentric distance sum index of a graph G is defined as ξsv(G)=∑v∈V(G)ε(v)D(v)deg(v), where D(v)=∑u∈V(G)d(u,v) is the sum of all distances from the vertex v. In this paper we derive some bounds for the adjacent eccentric distance sum index in terms of some graph parameters, such as independence number, covering number, vertex connectivity, chromatic number, diameter and some other graph topological indices. PMID:26091095

  3. Crystal Structures and Molecular Dynamics Simulations of Thermophilic Malate Dehydrogenase Reveal Critical Loop Motion for Co-Substrate Binding

    PubMed Central

    Luo, Huei-Ru; Wu, Szu-Pei; Hsu, Chun-Hua

    2013-01-01

    Malate dehydrogenase (MDH) catalyzes the conversion of oxaloacetate and malate by using the NAD/NADH coenzyme system. The system is used as a conjugate for enzyme immunoassays of a wide variety of compounds, such as illegal drugs, drugs used in therapeutic applications and hormones. We elucidated the biochemical and structural features of MDH from Thermus thermophilus (TtMDH) for use in various biotechnological applications. The biochemical characterization of recombinant TtMDH revealed greatly increased activity above 60°C and specific activity of about 2,600 U/mg with optimal temperature of 90°C. Analysis of crystal structures of apo and NAD-bound forms of TtMDH revealed a slight movement of the binding loop and few structural elements around the co-substrate binding packet in the presence of NAD. The overall structures did not change much and retained all related positions, which agrees with the CD analyses. Further molecular dynamics (MD) simulation at higher temperatures were used to reconstruct structures from the crystal structure of TtMDH. Interestingly, at the simulated structure of 353 K, a large change occurred around the active site such that with increasing temperature, a mobile loop was closed to co-substrate binding region. From biochemical characterization, structural comparison and MD simulations, the thermal-induced conformational change of the co-substrate binding loop of TtMDH may contribute to the essential movement of the enzyme for admitting NAD and may benefit the enzyme's activity. PMID:24386145

  4. Critical thickness of high structural quality SrTiO3 films grown on orthorhombic (101) DyScO3

    SciTech Connect

    Hawley, Marilyn E; Biegalski, Michael D; Schlom, Darrell G

    2008-01-01

    Strained epitaxial SrTiO{sub 3} films were grown on orthorhombic (101) DyScO{sub 3} substrates by reactive molecular-beam epitaxy. The epitaxy of this substrate/film combination is cube on cube with a pseudocubic out-of-plane (001) orientation. The strain state and structural perfection of films with thicknesses ranging from 50 to 1000 {angstrom} were examined using x-ray scattering. The critical thickness at which misfit dislocations was introduced was between 350 and 500 {angstrom}. These films have the narrowest rocking curves (full width at half maximum) ever reported for any heteroepitaxial oxide film (0.0018{sup o}). Only a modest amount of relaxation is seen in films exceeding the critical thicknesses even after postdeposition annealing at 700{sup o}C in 1 atm of oxygen. The dependence of strain relaxation on crystallographic direction is attributed to the anisotropy of the substrate. These SrTiO{sub 3} films show structural quality more typical of semiconductors such as GaAs and silicon than perovskite materials; their structural relaxation behavior also shows similarity to that of compound semiconductor films.

  5. Structural Convergence between CryoEM and NMR Reveals Novel Intersubunit Interactions Critical for HIV-1 Capsid Function

    PubMed Central

    Byeon, In-Ja L.; Meng, Xin; Jung, Jinwon; Zhao, Gongpu; Yang, Ruifeng; Ahn, Jinwoo; Shi, Jiong; Concel, Jason; Aiken, Christopher; Zhang, Peijun; Gronenborn, Angela M.

    2009-01-01

    Summary Mature HIV-1 particles contain conical-shaped capsids that enclose the viral RNA genome and perform essential functions in the virus life cycle. Previous structural analysis of two and three-dimensional arrays provided a molecular model of the capsid protein (CA) hexamer and revealed three interfaces. Here, we present a cryoEM study of a tubular assembly of CA and a high-resolution NMR structure of the CA C-terminal domain (CTD) dimer. In the solution dimer structure, the monomers exhibit different relative orientations compared to previous X-ray structures. The solution structure fits extremely well into the EM density map, suggesting that the dimer interface is retained in the assembled CA. We also identified a novel CTD-CTD interface at the local three-fold axis in the cryoEM map and confirmed its functional importance by mutagenesis. In the tubular assembly, CA intermolecular interfaces vary slightly, accommodating the asymmetry present in tubes. This provides the necessary plasticity to allow for controlled virus capsid dis/assembly. PMID:19914170

  6. Critical Thoughts on Critical Thinking

    ERIC Educational Resources Information Center

    Cody, Dean E.

    2006-01-01

    Scholars in many academic areas, including librarians, devote a significant amount of thought to critical thinking. Surveying views of its use and possibility, the author considers some key librarians' thoughts on critical thinking. In conclusion, the inability to define critical thinking means that librarians need to emphasize control of…

  7. Critical Thinking vs. Critical Consciousness

    ERIC Educational Resources Information Center

    Doughty, Howard A.

    2006-01-01

    This article explores four kinds of critical thinking. The first is found in Socratic dialogues, which employ critical thinking mainly to reveal logical fallacies in common opinions, thus cleansing superior minds of error and leaving philosophers free to contemplate universal verities. The second is critical interpretation (hermeneutics) which…

  8. Critically Thinking about Critical Thinking

    ERIC Educational Resources Information Center

    Weissberg, Robert

    2013-01-01

    In this article, the author states that "critical thinking" has mesmerized academics across the political spectrum and that even high school students are now being called upon to "think critically." He furthers adds that it is no exaggeration to say that "critical thinking" has quickly evolved into a scholarly…

  9. How Critical Is Critical Thinking?

    ERIC Educational Resources Information Center

    Shaw, Ryan D.

    2014-01-01

    Recent educational discourse is full of references to the value of critical thinking as a 21st-century skill. In music education, critical thinking has been discussed in relation to problem solving and music listening, and some researchers suggest that training in critical thinking can improve students' responses to music. But what exactly is…

  10. 7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL CONVEYOR; IN THE DISTANCE IS THE FREQUENCY CHANGER HOUSE, WHICH IS ATTACHED TO SWITCH HOUSE NO. 1; LOOKING WEST. - Commonwealth Electric Company, Fisk Street Electrical Generating Station, 1111 West Cermak Avenue, Chicago, Cook County, IL

  11. Colposcopy of vaginal and vulvar human papillomavirus and adjacent sites.

    PubMed

    Hatch, K

    1993-03-01

    Human papillomaviral infections can affect the entire lower female genital tract as multifocal or multicentric disease as well as the surrounding anatomic and adjacent sites. The traditional colposcopic methods are necessary to assist in the diagnosis and help differentiate these infections from other disease mimics. PMID:8392676

  12. Biogeochemistry of hydrothermally and adjacent non-altered soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a field/lab project, students in the Soil Biogeochemistry class of the University of Nevada, Reno described and characterized seven pedons, developed in hydrothermally and adjacent non-hydrothermally altered andesitic parent material near Reno, NV. Hydrothermally altered soils had considerably lo...

  13. 22. Float located adjacent to entry stair in filtration bed. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  14. 2. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING WEST. GEORGIA TECH DORMITORY BUILDING, 581-587 TECHWOOD DRIVE, IN FOREGROUND. - Techwood Homes (Public Housing), Bounded by North Avenue, Parker Street, William Street & Lovejoy Street, Atlanta, Fulton County, GA

  15. 10. Detail and contextual view of bridge and adjacent farmstead ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Detail and contextual view of bridge and adjacent farmstead setting. Note laced vertical compression members, latticed portal strut, decorative strut bracing, and lightness of diagonal and lateral tension members. View to southeast through southeast portal from truss mid-span. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

  16. LEHR NO. 2 AND LEHR NO. 3 ADJACENT TO FURNACE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LEHR NO. 2 AND LEHR NO. 3 ADJACENT TO FURNACE ROOM; THE PIPES AT THE BOTTOM ARE PART OF THE RADIANT HEATING SYSTEM USED FOR HEATING THE FACTORY DURING COLD WEATHER. - Westmoreland Glass Company, Seventh & Kier Streets, Grapeville, Westmoreland County, PA

  17. Effects on stink bugs of field edges adjacent to woodland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers face significant crop losses from stink bug species in the southeastern USA, but the high mobility and polyphagy of the bugs make predictions of their presence in crops difficult. While there is some evidence that they colonize crops from adjacent crops, there are no studies of their colo...

  18. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING INTERSECTION OF ACACIA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING INTERSECTION OF ACACIA ROAD WITH BIRCH CIRCLE. VIEW FACING NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  19. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ENTRY TO NEIGHBORHOOD. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  20. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING WESTERN SIDE OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING WESTERN SIDE OF NEIGHBORHOOD. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  1. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON RIGHT, AND HOUSING AREA ON LEFT. VIEW FACING EAST/NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  2. How subaerial salt extrusions influence water quality in adjacent aquifers

    NASA Astrophysics Data System (ADS)

    Mehdizadeh, Razieh; Zarei, Mehdi; Raeisi, Ezzat

    2015-12-01

    Brines supplied from salt extrusions cause significant groundwater salinization in arid and semi-arid regions where salt rock is exposed to dissolution by episodic rainfalls. Here we focus on 62 of the 122 diapirs of Hormuz salt emergent in the southern Iran. To consider managing the degradation effect that salt extrusions have on the quality of adjoining aquifers, it is first necessary to understand how they influence adjacent water resources. We evaluate here the impacts that these diapirs have on adjacent aquifers based on investigating their geomorphologies, geologies, hydrologies and hydrogeologies. The results indicate that 28/62 (45%) of our sample of salt diapirs have no significant impact on the quality of groundwater in adjoining aquifers (namely Type N), while the remaining 34/62 (55%) degrade nearby groundwater quality. We offer simple conceptual models that account for how brines flowing from each of these types of salt extrusions contaminate adjacent aquifers. We identify three main mechanisms that lead to contamination: surface impact (Type A), subsurface intrusion (Type B) and indirect infiltration (Type C). A combination of all these mechanisms degrades the water quality in nearby aquifers in 19/62 (31%) of the salt diapirs studied. Having characterized the mechanism(s) by which each diapir affects the adjacent aquifer, we suggest a few possible remediation strategies to be considered. For instance, engineering the surface runoff of diapirs Types A and C into nearby evaporation basins would improve groundwater quality.

  3. 45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, NORTH END OF MILL NO. 2, WALL ON LEFT DIVIDING CLOTH ROOM ADDED LATER (PROBABLY C. 1970s). - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  4. Detail of north intermediate abutment pylon showing proximity of adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of north intermediate abutment pylon showing proximity of adjacent 1001-1007 East First Street (James K. Hill and Sons Pickle Works Building), facing east - First Street Bridge, Spanning Los Angeles River at First Street, Los Angeles, Los Angeles County, CA

  5. 8. Exterior view, showing tank and associated piping adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Exterior view, showing tank and associated piping adjacent to Test Cell 6, Systems Integration Laboratory Building (T-28), looking south. - Air Force Plant PJKS, Systems Integration Laboratory, Systems Integration Laboratory Building, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  6. 4. REAR ELEVATION, DETAIL OF CONSTRUCTION, ADJACENT CORNER POSTS BETWEEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. REAR ELEVATION, DETAIL OF CONSTRUCTION, ADJACENT CORNER POSTS BETWEEN BUILDING PERIODS 1 AND 3. NOTE REUSED WOOD STRIP NAILED TO BUILDING PERIOD 1 POST INSCRIBED 'ST. LEONARD'. THERE ARE NO NAIL HOLES IN THE PERIOD 3 POST, THE FARRING STRIPS ADJUST FOR CLADDING - Charles' Gift, State Routes 2 & 4, Lusby, Calvert County, MD

  7. 1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION TOWER. WATER BRAKE TROUGH SEGMENT AT LOWER RIGHT. Looking north northeast. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  8. 4. Elevation looking southwest from adjacent hills on northeast side ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Elevation looking southwest from adjacent hills on northeast side of bridge, taken from river level. Note entire east side and substructure. - Presumpscot Falls Bridge, Spanning Presumptscot River at Allen Avenue extension, 0.75 mile west of U.S. Interstate 95, Falmouth, Cumberland County, ME

  9. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Signals at adjacent control points. 236.404 Section 236.404 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR...

  10. 12. LOG FOUNDATION ELEMENTS OF THE SAWMILL ADJACENT TO THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. LOG FOUNDATION ELEMENTS OF THE SAWMILL ADJACENT TO THE CANAL, LOOKING EAST. BARREN AREA IN FOREGROUND IS DECOMPOSING SAWDUST. DIRT PILE IN BACKGROUND IS THE EDGE OF THE SUMMIT COUNTY LANDFILL. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO

  11. Prose and Poetry Classification and Boundary Detection Using Word Adjacency Network Analysis

    NASA Astrophysics Data System (ADS)

    Roxas, Ranzivelle Marianne; Tapang, Giovanni

    Word adjacency networks constructed from written works reflect differences in the structure of prose and poetry. We present a method to disambiguate prose and poetry by analyzing network parameters of word adjacency networks, such as the clustering coefficient, average path length and average degree. We determine the relevant parameters for disambiguation using linear discriminant analysis (LDA) and the effect size criterion. The accuracy of the method is 74.9 ± 2.9% for the training set and 73.7 ± 6.4% for the test set which are greater than the acceptable classifier requirement of 67.3%. This approach is also useful in locating text boundaries within a single article which falls within a window size where the significant change in clustering coefficient is observed. Results indicate that an optimal window size of 75 words can detect the text boundaries.

  12. Resonant optical transmission through a one-dimensional photonic crystal adjacent to a thin metal film

    NASA Astrophysics Data System (ADS)

    Yuan, Chang-Sheng; Tang, Han; He, Cheng; Chen, Xiao-Lin; Ni, Xu; Lu, Ming-Hui; Chen, Yan-Feng; Ming, Nai-Ben

    2011-05-01

    We theoretically and experimentally reveal that the large resonant optical transmission (ROT) can be realized through a one-dimensional photonic crystal adjacent to a thin metal film, at a frequency in the original band-gap of the photonic crystal (PC). The influence of periodic number of PC and the thickness of the adjacent metal on the transmission frequency and intensity is studied in detail. An optimum design is given to reach the maximum transmission efficiency, meanwhile a mechanism underlining the ROT phenomenon is proposed. An effective admittance-matching theory is proposed to understand this effect and quantitatively determine the operating frequency, which matches very well with the simulated and measured results. The effects might be very useful to realize some optical filters and sensor devices since the structure is easy for mass production and is matured technically to be prepared in industry.

  13. Reflection on Teaching and Epistemological Structure: Reflective and Critically Reflective Processes in "Pure/Soft" and "Pure/Hard" Fields

    ERIC Educational Resources Information Center

    Kreber, Carolin; Castleden, Heather

    2009-01-01

    We empirically explored whether academics from pure/soft and pure/hard fields engage in reflective practice on teaching differently and, if so, whether these differences could be partially explained by the epistemological structure of their discipline. Interview data from academics in pure/hard (N = 30) and pure/soft fields (N = 10) were…

  14. Protein Structural Studies by Traveling Wave Ion Mobility Spectrometry: A Critical Look at Electrospray Sources and Calibration Issues.

    PubMed

    Sun, Yu; Vahidi, Siavash; Sowole, Modupeola A; Konermann, Lars

    2016-01-01

    The question whether electrosprayed protein ions retain solution-like conformations continues to be a matter of debate. One way to address this issue involves comparisons of collision cross sections (Ω) measured by ion mobility spectrometry (IMS) with Ω values calculated for candidate structures. Many investigations in this area employ traveling wave IMS (TWIMS). It is often implied that nanoESI is more conducive for the retention of solution structure than regular ESI. Focusing on ubiquitin, cytochrome c, myoglobin, and hemoglobin, we demonstrate that Ω values and collisional unfolding profiles are virtually indistinguishable under both conditions. These findings suggest that gas-phase structures and ion internal energies are independent of the type of electrospray source. We also note that TWIMS calibration can be challenging because differences in the extent of collisional activation relative to drift tube reference data may lead to ambiguous peak assignments. It is demonstrated that this problem can be circumvented by employing collisionally heated calibrant ions. Overall, our data are consistent with the view that exposure of native proteins to electrospray conditions can generate kinetically trapped ions that retain solution-like structures on the millisecond time scale of TWIMS experiments. ᅟ PMID:26369778

  15. Protein Structural Studies by Traveling Wave Ion Mobility Spectrometry: A Critical Look at Electrospray Sources and Calibration Issues

    NASA Astrophysics Data System (ADS)

    Sun, Yu; Vahidi, Siavash; Sowole, Modupeola A.; Konermann, Lars

    2016-01-01

    The question whether electrosprayed protein ions retain solution-like conformations continues to be a matter of debate. One way to address this issue involves comparisons of collision cross sections (Ω) measured by ion mobility spectrometry (IMS) with Ω values calculated for candidate structures. Many investigations in this area employ traveling wave IMS (TWIMS). It is often implied that nanoESI is more conducive for the retention of solution structure than regular ESI. Focusing on ubiquitin, cytochrome c, myoglobin, and hemoglobin, we demonstrate that Ω values and collisional unfolding profiles are virtually indistinguishable under both conditions. These findings suggest that gas-phase structures and ion internal energies are independent of the type of electrospray source. We also note that TWIMS calibration can be challenging because differences in the extent of collisional activation relative to drift tube reference data may lead to ambiguous peak assignments. It is demonstrated that this problem can be circumvented by employing collisionally heated calibrant ions. Overall, our data are consistent with the view that exposure of native proteins to electrospray conditions can generate kinetically trapped ions that retain solution-like structures on the millisecond time scale of TWIMS experiments.

  16. Structural Determinant of Human La Protein Critical for Internal Initiation of Translation of Hepatitis C Virus RNA ▿ †

    PubMed Central

    Mondal, Tanmoy; Ray, Upasana; Manna, Asit Kumar; Gupta, Romi; Roy, Siddhartha; Das, Saumitra

    2008-01-01

    Human La protein has been implicated in facilitating internal ribosome entry site (IRES)-mediated translation of hepatitis C virus (HCV). Earlier, we demonstrated that the RNA recognition motif (RRM) encompassing residues 112 to 184 of La protein [La (112-184)] interacts with the HCV IRES near the initiator AUG codon. A synthetic peptide, LaR2C (24-mer), derived from La RRM (112-184), retains RNA binding ability, competes with La protein binding to the HCV IRES, and inhibits translation. The peptide interferes with the assembly of 48S complexes, resulting in the accumulation of preinitiation complexes that are incompetent for the 60S ribosomal subunit joining. Here, nuclear magnetic resonance spectroscopy of the HCV IRES-bound peptide complex revealed putative contact points, mutations that showed reduced RNA binding and translation inhibitory activity. The residues responsible for RNA recognition were found to form a turn in the RRM (112-184) structure. A 7-mer peptide comprising this turn showed significant translation inhibitory activity. The bound structure of the peptide inferred from transferred nuclear Overhauser effect experiments suggests that it is a β turn. This conformation is significantly different from that observed in the free RRM (112-184) NMR structure, suggesting paths toward a better-stabilized mimetic peptide. Interestingly, addition of hexa-arginine tag enabled the peptide to enter Huh7 cells and showed inhibition of HCV IRES function. More importantly, the peptide significantly inhibited replication of the HCV monocistronic replicon. Elucidation of the structural determinant of the peptide provides a basis for developing small peptidomimetic structures as potent anti-HCV therapeutics. PMID:18829760

  17. The relationship between critical thinking and how time is structured in the clinical setting for students in a baccalaureate nursing program.

    PubMed

    Graham, M E

    1995-01-01

    This experimental study was undertaken to investigate the relationship between critical thinking and how time is structured in the clinical setting. A total of 93 respondents completed the Watson-Glaser Critical Thinking Appraisal (CTA) Form: 35 in the comparison group, 29 in the 2-hour/8-hour clinical groups, and 29 in the 5-hour/5-hour clinical groups. Results of the ANOVA test shows that, at Time 1, students in the comparison group had the lowest mean score (9.23) and the 2-hour/8-hour clinical groups had the highest mean score (10.94), suggesting that the three groups were not equal at Time 1 in terms of their critical thinking ability. Nevertheless, the within subjects effects shows that while all three groups indicate positive Time 1-Time 2 changes, only the 5-hour/5-hour groups show a substantial degree of improvement (10.04 to 10.75), i.e., the study groups x time interaction effect is significant (p < .001). This pattern of significance between subjects effects and differential changes in CTA scores over time, with the 5-hour/5-hour groups showing the largest degree of change is consistent among the fine sub-component of the Watson-Glaser Scale. Students in the 5-hour/5-hour groups showed the most improvement in their scores in the area of Interpretation and Evaluation of arguments which was 9.55 at Time 1 and 10.52 at Time 2. PMID:8714922

  18. Early Growth Response1and Fatty Acid Synthase Expression is Altered in Tumor Adjacent Prostate Tissue and Indicates Field Cancerization

    PubMed Central

    Jones, Anna C.; Trujillo, Kristina A.; Phillips, Genevieve K.; Fleet, Trisha M.; Murton, Jaclyn K.; Severns, Virginia; Shah, Satyan K.; Davis, Michael S.; Smith, Anthony Y.; Griffith, Jeffrey K.; Fischer, Edgar G.; Bisoffi, Marco

    2011-01-01

    BACKGROUND Field cancerization denotes the occurrence of molecular alterations in histologically normal tissues adjacent to tumors. In prostate cancer, identification of field cancerization has several potential clinical applications. However, prostate field cancerization remains ill defined. Our previous work has shown up-regulated mRNA of the transcription factor early growth response 1 (EGR-1) and the lipogenic enzyme fatty acid synthase (FAS) in tissues adjacent to prostate cancer. METHODS Immunofluorescence data were analyzed quantitatively by spectral imaging and linear unmixing to determine the protein expression levels of EGR-1 and FAS in human cancerous, histologically normal adjacent, and disease-free prostate tissues. RESULTS EGR-1 expression was elevated in both structurally intact tumor adjacent (1.6× on average) and in tumor (3.0× on average) tissues compared to disease-free tissues. In addition, the ratio of cytoplasmic versus nuclear EGR-1 expression was elevated in both tumor adjacent and tumor tissues. Similarly, FAS expression was elevated in both tumor adjacent (2.7× on average) and in tumor (2.5× on average) compared to disease-free tissues. CONCLUSIONS EGR-1 and FAS expression is similarly deregulated in tumor and structurally intact adjacent prostate tissues and defines field cancerization. In cases with high suspicion of prostate cancer but negative biopsy, identification of field cancerization could help clinicians target areas for repeat biopsy. Field cancerization at surgical margins on prostatectomy specimen should also be looked at as a predictor of cancer recurrence. EGR-1 and FAS could also serve as molecular targets for chemoprevention. PMID:22127986

  19. Structure and function of Plasmodium falciparum malate dehydrogenase: role of critical amino acids in co-substrate binding pocket.

    PubMed

    Pradhan, Anupam; Tripathi, Abhai K; Desai, Prashant V; Mukherjee, Prasenjit K; Avery, Mitchell A; Walker, Larry A; Tekwani, Babu L

    2009-01-01

    The malaria parasite thrives on anaerobic fermentation of glucose for energy. Earlier studies from our laboratory have demonstrated that a cytosolic malate dehydrogenase (PfMDH) with striking similarity to lactate dehydrogenase (PfLDH) might complement PfLDH function in Plasmodium falciparum. The N-terminal glycine motif, which forms a characteristic Rossman dinucleotide-binding fold in the co-substrate binding pocket, differentiates PfMDH (GlyXGlyXXGly) from other eukaryotic and prokaryotic malate dehydrogenases (GlyXXGlyXXGly). The amino acids lining the co-substrate binding pocket are completely conserved in MDHs from different species of human, primate and rodent malaria parasites. Based on this knowledge and conserved domains among prokaryotic and eukaryotic MDH, the role of critical amino acids lining the co-substrate binding pocket was analyzed in catalytic functions of PfMDH using site-directed mutagenesis. Insertion of Ala at the 9th or 10th position, which converts the N-terminal GlyXGlyXXGly motif (characteristic of malarial MDH and LDH) to GlyXXGlyXXGly (as in bacterial and eukaryotic MDH), uncoupled regulation of the enzyme through substrate inhibition. The dinucleotide fold GlyXGlyXXGly motif seems not to be responsible for the distinct affinity of PfMDH to 3-acetylpyridine-adenine dinucleotide (APAD, a synthetic analog of NAD), since Ala9 and Ala10 insertion mutants still utilized APADH. The Gln11Met mutation, which converts the signature glycine motif in PfMDH to that of PfLDH, did not change the enzyme function. However, the Gln11Gly mutant showed approximately a 5-fold increase in catalytic activity, and higher susceptibility to inhibition with gossypol. Asn119 and His174 participate in binding of both co-substrate and substrate. The Asn119Gly mutant exhibited approximately a 3-fold decrease in catalytic efficiency, while mutation of His174 to Asn or Ala resulted in an inactive enzyme. These studies provide critical insights into the co

  20. Seismotectonics of northeastern United States and adjacent Canada

    NASA Astrophysics Data System (ADS)

    Yang, Jih-Ping; Aggarwal, Yash Pal

    1981-06-01

    Data for local earthquakes recorded by a network of stations in northeastern United States and adjacent Canada were analyzed to study the seismicity, the relationship between earthquakes and known faults, the state of stress, and crustal and upper mantle velocity structure. In addition, portable seismographs were deployed in the field to study aftershocks. As a result, accurate locations for about 364 local earthquakes (2 ≤ mb ≤ 5) and 22 focal mechanism solutions were determined. A comparison of the spatial distribution of these events (1970-1979) with historical earthquakes (1534-1959) reveals that seismic activity in the northeast is relatively stationary in space: those areas that have had little or no seismicity historically are relatively aseismic today, whereas the historically active areas are also active today. The instrumental locations, historical seismicity, and focal mechanism solutions show an internal consistency that help us distinguish two distinct seismogenic provinces. (1) The Adirondack-western Quebec province is a northwesterly trending zone of seismic activity, about 200 km wide and at least 500 km long, extending from the SE Adirondacks into western Quebec, Canada. Thrust faulting on planes striking NNW to NW appears to predominate, and the inferred axis of maximum horizontal compression is largely uniform and trends WSW, nearly parallel to the calculated absolute plate motion of North America. Little or no seismicity is found where anorthosite outcrops at the surface. Correlations between gravity anomalies and earthquake locations suggest that seismic activity in this zone is localized to regions of steep NE or SW gradient in Bouguer anomalies. This zone does not appear to extend southeastward to Boston, as proposed by some workers. (2) The Appalachian province is a northeasterly trending zone of seismic activity extending from northern Virginia to New Brunswick, Canada. Highangle reverse or thrust faulting on N to NE trending planes

  1. Structural Insight into the Critical Role of the N-Terminal Region in the Catalytic Activity of Dual-Specificity Phosphatase 26.

    PubMed

    Won, Eun-Young; Lee, Sang-Ok; Lee, Dong-Hwa; Lee, Daeyoup; Bae, Kwang-Hee; Lee, Sang Chul; Kim, Seung Jun; Chi, Seung-Wook

    2016-01-01

    Human dual-specificity phosphatase 26 (DUSP26) is a novel target for anticancer therapy because its dephosphorylation of the p53 tumor suppressor regulates the apoptosis of cancer cells. DUSP26 inhibition results in neuroblastoma cell cytotoxicity through p53-mediated apoptosis. Despite the previous structural studies of DUSP26 catalytic domain (residues 61-211, DUSP26-C), the high-resolution structure of its catalytically active form has not been resolved. In this study, we determined the crystal structure of a catalytically active form of DUSP26 (residues 39-211, DUSP26-N) with an additional N-terminal region at 2.0 Å resolution. Unlike the C-terminal domain-swapped dimeric structure of DUSP26-C, the DUSP26-N (C152S) monomer adopts a fold-back conformation of the C-terminal α8-helix and has an additional α1-helix in the N-terminal region. Consistent with the canonically active conformation of its protein tyrosine phosphate-binding loop (PTP loop) observed in the structure, the phosphatase assay results demonstrated that DUSP26-N has significantly higher catalytic activity than DUSP26-C. Furthermore, size exclusion chromatography-multiangle laser scattering (SEC-MALS) measurements showed that DUSP26-N (C152S) exists as a monomer in solution. Notably, the crystal structure of DUSP26-N (C152S) revealed that the N-terminal region of DUSP26-N (C152S) serves a scaffolding role by positioning the surrounding α7-α8 loop for interaction with the PTP-loop through formation of an extensive hydrogen bond network, which seems to be critical in making the PTP-loop conformation competent for phosphatase activity. Our study provides the first high-resolution structure of a catalytically active form of DUSP26, which will contribute to the structure-based rational design of novel DUSP26-targeting anticancer therapeutics. PMID:27583453

  2. Structural insights into the effect of cholinium-based ionic liquids on the critical micellization temperature of aqueous triblock copolymers.

    PubMed

    Khan, Imran; Umapathi, Reddicherla; Neves, Márcia C; Coutinho, João A P; Venkatesu, Pannuru

    2016-03-16

    Symmetrical poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG) triblock copolymer with 82.5% PEG as the hydrophilic end blocks, and PPG as the hydrophobic middle block, was chosen to study the effect of ionic liquids (ILs) on the critical micellization temperature (CMT) of block copolymers in aqueous solution. In the present work, cholinium-based ILs were chosen to explore the effect of the anions on the copolymer CMT using fluorescence spectroscopy, dynamic light scattering (DLS), viscosity (η), FT-IR spectroscopy, nuclear magnetic resonance (NMR), and direct visualization of the various self-assembled nanostructures by scanning electron microscopy (SEM). The result suggests that ILs have the ability to decrease the CMT of the aqueous copolymer solution which is dependent on the nature of the anions of the ILs. The present study reveals that the hydrophobic part PPG of the copolymer has more influence on this behavior than the PEG hydrophilic part. PMID:26700649

  3. Crystal structures of ryanodine receptor SPRY1 and tandem-repeat domains reveal a critical FKBP12 binding determinant

    NASA Astrophysics Data System (ADS)

    Yuchi, Zhiguang; Yuen, Siobhan M. Wong King; Lau, Kelvin; Underhill, Ainsley Q.; Cornea, Razvan L.; Fessenden, James D.; van Petegem, Filip

    2015-08-01

    Ryanodine receptors (RyRs) form calcium release channels located in the membranes of the sarcoplasmic and endoplasmic reticulum. RyRs play a major role in excitation-contraction coupling and other Ca2+-dependent signalling events, and consist of several globular domains that together form a large assembly. Here we describe the crystal structures of the SPRY1 and tandem-repeat domains at 1.2-1.5 Å resolution, which reveal several structural elements not detected in recent cryo-EM reconstructions of RyRs. The cryo-EM studies disagree on the position of SPRY domains, which had been proposed based on homology modelling. Computational docking of the crystal structures, combined with FRET studies, show that the SPRY1 domain is located next to FK506-binding protein (FKBP). Molecular dynamics flexible fitting and mutagenesis experiments suggest a hydrophobic cluster within SPRY1 that is crucial for FKBP binding. A RyR1 disease mutation, N760D, appears to directly impact FKBP binding through interfering with SPRY1 folding.

  4. Crystal structures of Ryanodine Receptor SPRY1 and tandem-repeat domains reveal a critical FKBP12 binding determinant

    PubMed Central

    Yuchi, Zhiguang; Wong King Yuen, Siobhan M.; Lau, Kelvin; Underhill, Ainsley Q.; Cornea, Razvan L.; Fessenden, James D.; Van Petegem, Filip

    2015-01-01

    Ryanodine receptors (RyRs) form calcium release channels located in the membranes of the sarcoplasmic and endoplasmic reticulum. RyRs play a major role in excitation-contraction coupling and other Ca2+-dependent signaling events, and consist of several globular domains that together form a large assembly. Here we describe the crystal structures of the SPRY1 and tandem-repeat domains at 1.2 – 1.5Å resolution, which reveal several structural elements not detected in recent cryo-EM reconstructions of RyRs. The cryo-EM studies disagree on the position of SPRY domains, which had been proposed based on homology modeling. Computational docking of the crystal structures, combined with FRET studies, show that the SPRY1 domain is located next to FK506-Binding Protein (FKBP). Molecular dynamics flexible fitting and mutagenesis experiments suggest a hydrophobic cluster within SPRY1 that is crucial for FKBP binding. A RyR1 disease mutation, N760D, appears to directly impact FKBP binding through interfering with SPRY1 folding. PMID:26245150

  5. Criticality Model

    SciTech Connect

    A. Alsaed

    2004-09-14

    The ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003) presents the methodology for evaluating potential criticality situations in the monitored geologic repository. As stated in the referenced Topical Report, the detailed methodology for performing the disposal criticality analyses will be documented in model reports. Many of the models developed in support of the Topical Report differ from the definition of models as given in the Office of Civilian Radioactive Waste Management procedure AP-SIII.10Q, ''Models'', in that they are procedural, rather than mathematical. These model reports document the detailed methodology necessary to implement the approach presented in the Disposal Criticality Analysis Methodology Topical Report and provide calculations utilizing the methodology. Thus, the governing procedure for this type of report is AP-3.12Q, ''Design Calculations and Analyses''. The ''Criticality Model'' is of this latter type, providing a process evaluating the criticality potential of in-package and external configurations. The purpose of this analysis is to layout the process for calculating the criticality potential for various in-package and external configurations and to calculate lower-bound tolerance limit (LBTL) values and determine range of applicability (ROA) parameters. The LBTL calculations and the ROA determinations are performed using selected benchmark experiments that are applicable to various waste forms and various in-package and external configurations. The waste forms considered in this calculation are pressurized water reactor (PWR), boiling water reactor (BWR), Fast Flux Test Facility (FFTF), Training Research Isotope General Atomic (TRIGA), Enrico Fermi, Shippingport pressurized water reactor, Shippingport light water breeder reactor (LWBR), N-Reactor, Melt and Dilute, and Fort Saint Vrain Reactor spent nuclear fuel (SNF). The scope of this analysis is to document the criticality computational method. The criticality

  6. Critical Care

    MedlinePlus

    Critical care helps people with life-threatening injuries and illnesses. It might treat problems such as complications from surgery, accidents, infections, and severe breathing problems. It involves ...

  7. Structural Studies of Lipopolysaccharide-defective Mutants from Brucella melitensis Identify a Core Oligosaccharide Critical in Virulence.

    PubMed

    Fontana, Carolina; Conde-Álvarez, Raquel; Ståhle, Jonas; Holst, Otto; Iriarte, Maite; Zhao, Yun; Arce-Gorvel, Vilma; Hanniffy, Seán; Gorvel, Jean-Pierre; Moriyón, Ignacio; Widmalm, Göran

    2016-04-01

    The structures of the lipooligosaccharides fromBrucella melitensismutants affected in the WbkD and ManBcoreproteins have been fully characterized using NMR spectroscopy. The results revealed that disruption ofwbkDgives rise to a rough lipopolysaccharide (R-LPS) with a complete core structure (β-d-Glcp-(1→4)-α-Kdop-(2→4)[β-d-GlcpN-(1→6)-β-d-GlcpN-(1→4)[β-d-GlcpN-(1→6)]-β-d-GlcpN-(1→3)-α-d-Manp-(1→5)]-α-Kdop-(2→6)-β-d-GlcpN3N4P-(1→6)-α-d-GlcpN3N1P), in addition to components lacking one of the terminal β-d-GlcpN and/or the β-d-Glcpresidues (48 and 17%, respectively). These structures were identical to those of the R-LPS fromB. melitensisEP, a strain simultaneously expressing both smooth and R-LPS, also studied herein. In contrast, disruption ofmanBcoregives rise to a deep-rough pentasaccharide core (β-d-Glcp-(1→4)-α-Kdop-(2→4)-α-Kdop-(2→6)-β-d-GlcpN3N4P-(1→6)-α-d-GlcpN3N1P) as the major component (63%), as well as a minor tetrasaccharide component lacking the terminal β-d-Glcpresidue (37%). These results are in agreement with the predicted functions of the WbkD (glycosyltransferase involved in the biosynthesis of the O-antigen) and ManBcoreproteins (phosphomannomutase involved in the biosynthesis of a mannosyl precursor needed for the biosynthesis of the core and O-antigen). We also report that deletion ofB. melitensis wadCremoves the core oligosaccharide branch not linked to the O-antigen causing an increase in overall negative charge of the remaining LPS inner section. This is in agreement with the mannosyltransferase role predicted for WadC and the lack of GlcpN residues in the defective core oligosaccharide. Despite carrying the O-antigen essential inB. melitensisvirulence, the core deficiency in thewadCmutant structure resulted in a more efficient detection by innate immunity and attenuation, proving the role of the β-d-GlcpN-(1→6)-β-d-GlcpN-(1→4)[β-d-GlcpN-(1→6)]-β-d-GlcpN-(1→3)-α-d-Manp-(1→5) structure

  8. A critical study of novel physically structured lipid matrices composed of a homolipid from Capra hircus and theobroma oil.

    PubMed

    Attama, A A; Müller-Goymann, C C

    2006-09-28

    There is increasing interest in drug formulation using lipids. In this study, some physically structured lipid matrices were formulated and characterized for drug delivery applications. Lipid matrices containing a novel homolipid from Capra hircus (goat fat) and theobroma oil, at 25, 50 and 75% (w/w) concentration of the homolipid were formulated by fusion. The lipid matrices were subjected to some characterization procedures such as differential scanning calorimetry (DSC) to ascertain their supramolecular properties, small angle X-ray diffraction (SAXD), wide angle X-ray diffraction (WAXD), polarized light microscopy (PLM) and isothermal heat conduction microcalorimetry (IMC). The internal structures of some selected lipid matrices were also studied by freeze-fracture transmission electron microscopy (FFTEM). DSC results obtained indicated that goat fat has a pre-transition at 15.9 +/- 0.2 degrees C (after 1 week) and melts completely with two detectable melting peaks at 33.0 +/- 0.2 and 49.9 +/- 0.1 degrees C, and total enthalpy of 99.9 +/- 2.5 mJ/mg determined after 6 weeks of preparation. The melting enthalpy of goat fat changed after 3 weeks but remained constant after 6 weeks while the melting enthalpy of the lipid matrix containing 50% (w/w) goat fat changed after 3 and 6 weeks. An increase in lower melting peak was observed in the lipid matrix containing 25% (w/w) goat fat after 6 weeks. WAXD and SAXD of the physically structured lipid matrices showed reflections of the different pure lipids but new interferences were detected in WAXD mostly between 2theta=17.5 degrees and 2theta=27.5 degrees . PLM observation revealed the presence of Maltese crosses for the homolipid at 37 degrees C, which disappeared upon heating at 51.0 degrees C. PLM of the structured lipid matrix containing 25% (w/w) goat fat showed distinct crystal growth after 4 weeks among the admixtures. However, IMC studies did not reveal any change in recrystallization behaviour in this lipid

  9. Structural Studies of Lipopolysaccharide-defective Mutants from Brucella melitensis Identify a Core Oligosaccharide Critical in Virulence*

    PubMed Central

    Fontana, Carolina; Conde-Álvarez, Raquel; Ståhle, Jonas; Holst, Otto; Iriarte, Maite; Zhao, Yun; Arce-Gorvel, Vilma; Hanniffy, Seán; Gorvel, Jean-Pierre; Moriyón, Ignacio; Widmalm, Göran

    2016-01-01

    The structures of the lipooligosaccharides from Brucella melitensis mutants affected in the WbkD and ManBcore proteins have been fully characterized using NMR spectroscopy. The results revealed that disruption of wbkD gives rise to a rough lipopolysaccharide (R-LPS) with a complete core structure (β-d-Glcp-(1→4)-α-Kdop-(2→4)[β-d-GlcpN-(1→6)-β-d-GlcpN-(1→4)[β-d-GlcpN-(1→6)]-β-d-GlcpN-(1→3)-α-d-Manp-(1→5)]-α-Kdop-(2→6)-β-d-GlcpN3N4P-(1→6)-α-d-GlcpN3N1P), in addition to components lacking one of the terminal β-d-GlcpN and/or the β-d-Glcp residues (48 and 17%, respectively). These structures were identical to those of the R-LPS from B. melitensis EP, a strain simultaneously expressing both smooth and R-LPS, also studied herein. In contrast, disruption of manBcore gives rise to a deep-rough pentasaccharide core (β-d-Glcp-(1→4)-α-Kdop-(2→4)-α-Kdop-(2→6)-β-d-GlcpN3N4P-(1→6)-α-d-GlcpN3N1P) as the major component (63%), as well as a minor tetrasaccharide component lacking the terminal β-d-Glcp residue (37%). These results are in agreement with the predicted functions of the WbkD (glycosyltransferase involved in the biosynthesis of the O-antigen) and ManBcore proteins (phosphomannomutase involved in the biosynthesis of a mannosyl precursor needed for the biosynthesis of the core and O-antigen). We also report that deletion of B. melitensis wadC removes the core oligosaccharide branch not linked to the O-antigen causing an increase in overall negative charge of the remaining LPS inner section. This is in agreement with the mannosyltransferase role predicted for WadC and the lack of GlcpN residues in the defective core oligosaccharide. Despite carrying the O-antigen essential in B. melitensis virulence, the core deficiency in the wadC mutant structure resulted in a more efficient detection by innate immunity and attenuation, proving the role of the β-d-GlcpN-(1→6)-β-d-GlcpN-(1→4)[β-d-GlcpN-(1→6)]-β-d-GlcpN-(1→3)-

  10. Using discharge data to reduce structural deficits in a hydrological model with a Bayesian inference approach and the implications for the prediction of critical source areas

    NASA Astrophysics Data System (ADS)

    Frey, M. P.; Stamm, C.; Schneider, M. K.; Reichert, P.

    2011-12-01

    A distributed hydrological model was used to simulate the distribution of fast runoff formation as a proxy for critical source areas for herbicide pollution in a small agricultural catchment in Switzerland. We tested to what degree predictions based on prior knowledge without local measurements could be improved upon relying on observed discharge. This learning process consisted of five steps: For the prior prediction (step 1), knowledge of the model parameters was coarse and predictions were fairly uncertain. In the second step, discharge data were used to update the prior parameter distribution. Effects of uncertainty in input data and model structure were accounted for by an autoregressive error model. This step decreased the width of the marginal distributions of parameters describing the lower boundary (percolation rates) but hardly affected soil hydraulic parameters. Residual analysis (step 3) revealed model structure deficits. We modified the model, and in the subsequent Bayesian updating (step 4) the widths of the posterior marginal distributions were reduced for most parameters compared to those of the prior. This incremental procedure led to a strong reduction in the uncertainty of the spatial prediction. Thus, despite only using spatially integrated data (discharge), the spatially distributed effect of the improved model structure can be expected to improve the spatially distributed predictions also. The fifth step consisted of a test with independent spatial data on herbicide losses and revealed ambiguous results. The comparison depended critically on the ratio of event to preevent water that was discharged. This ratio cannot be estimated from hydrological data only. The results demonstrate that the value of local data is strongly dependent on a correct model structure. An iterative procedure of Bayesian updating, model testing, and model modification is suggested.

  11. Structural Analysis of the Interaction between Dishevelled2 and Clathrin AP-2 Adaptor, A Critical Step in Noncanonical Wnt Signaling

    SciTech Connect

    Yu, Anan; Xing, Yi; Harrison, Stephen C.; Kirchhausen, Tomas

    2010-10-14

    Wnt association with its receptor, Frizzled (Fz), and recruitment by the latter of an adaptor, Dishevelled (Dvl), initiates signaling through at least two distinct pathways (canonical and noncanonical). Endocytosis and compartmentalization help determine the signaling outcome. Our previous work has shown that Dvl2 links at least one Frizzled family member (Fz4) to clathrin-mediated endocytosis by interacting with the {mu}2 subunit of the AP-2 clathrin adaptor, through both a classical endocytic tyrosine motif and a so-called DEP domain. We report here the crystal structure of a chimeric protein that mimics the Dvl2-{mu}2 complex. The DEP domain binds at one end of the elongated, C-terminal domain of {mu}2. This domain:domain interface shows that parts of the {mu}2 surface distinct from the tyrosine-motif site can help recruit specific receptors or adaptors into a clathrin coated pit. Mutation of residues at the DEP-{mu}2 contact or in the tyrosine motif reduce affinity of Dvl2 for {mu}2 and block efficient internalization of Fz4 in response to ligation by Wnt5a. The crystal structure has thus allowed us to identify the specific interaction that leads to Frizzled uptake and to downstream, noncanonical signaling events.

  12. Structural Identification of the Vps18 β-Propeller Reveals a Critical Role in the HOPS Complex Stability and Function*

    PubMed Central

    Behrmann, Heide; Lürick, Anna; Kuhlee, Anne; Balderhaar, Henning Kleine; Bröcker, Cornelia; Kümmel, Daniel; Engelbrecht-Vandré, Siegfried; Gohlke, Ulrich; Raunser, Stefan; Heinemann, Udo; Ungermann, Christian

    2014-01-01

    Membrane fusion at the vacuole, the lysosome equivalent in yeast, requires the HOPS tethering complex, which is recruited by the Rab7 GTPase Ypt7. HOPS provides a template for the assembly of SNAREs and thus likely confers fusion at a distinct position on vacuoles. Five of the six subunits in HOPS have a similar domain prediction with strong similarity to COPII subunits and nuclear porins. Here, we show that Vps18 indeed has a seven-bladed β-propeller as its N-terminal domain by revealing its structure at 2.14 Å. The Vps18 N-terminal domain can interact with the N-terminal part of Vps11 and also binds to lipids. Although deletion of the Vps18 N-terminal domain does not preclude HOPS assembly, as revealed by negative stain electron microscopy, the complex is instable and cannot support membrane fusion in vitro. We thus conclude that the β-propeller of Vps18 is required for HOPS stability and function and that it can serve as a starting point for further structural analyses of the HOPS tethering complex. PMID:25324549

  13. Critical Muralism

    ERIC Educational Resources Information Center

    Rosette, Arturo

    2009-01-01

    This study focuses on the development and practices of Critical Muralists--community-educator-artist-leader-activists--and situates these specifically in relation to the Mexican mural tradition of los Tres Grandes and in relation to the history of public art more generally. The study examines how Critical Muralists address artistic and…

  14. Interaction between two adjacent grounded sources in frequency domain semi-airborne electromagnetic survey

    NASA Astrophysics Data System (ADS)

    Zhou, Haigen; Lin, Jun; Liu, Changsheng; Kang, Lili; Li, Gang; Zeng, Xinsen

    2016-03-01

    Multi-source and multi-frequency emission method can make full use of the valuable and short flight time in frequency domain semi-airborne electromagnetic (FSAEM) exploration, which has potential to investigate the deep earth structure in complex terrain region. Because several sources are adjacent in multi-source emission method, the interaction of different sources should be considered carefully. An equivalent circuit model of dual-source is established in this paper to assess the interaction between two individual sources, where the parameters are given with the typical values based on the practical instrument system and its application. By simulating the output current of two sources in different cases, the influence from the adjacent source is observed clearly. The current waveforms show that the mutual resistance causes the fluctuation and drift in another source and that the mutual inductance causes transient peaks. A field test with dual-source was conducted to certify the existence of interaction between adjacent sources. The simulation of output current also shows that current errors at low frequency are mainly caused by the mutual resistance while those at high frequency are mainly due to the mutual inductance. Increasing the distance between neighboring sources is a proposed measure to reduce the emission signal errors with designed ones. The feasible distance is discussed in the end. This study gives a useful guidance to lay multi sources to meet the requirement of measurement accuracy in FSAEM survey.

  15. Interaction between two adjacent grounded sources in frequency domain semi-airborne electromagnetic survey.

    PubMed

    Zhou, Haigen; Lin, Jun; Liu, Changsheng; Kang, Lili; Li, Gang; Zeng, Xinsen

    2016-03-01

    Multi-source and multi-frequency emission method can make full use of the valuable and short flight time in frequency domain semi-airborne electromagnetic (FSAEM) exploration, which has potential to investigate the deep earth structure in complex terrain region. Because several sources are adjacent in multi-source emission method, the interaction of different sources should be considered carefully. An equivalent circuit model of dual-source is established in this paper to assess the interaction between two individual sources, where the parameters are given with the typical values based on the practical instrument system and its application. By simulating the output current of two sources in different cases, the influence from the adjacent source is observed clearly. The current waveforms show that the mutual resistance causes the fluctuation and drift in another source and that the mutual inductance causes transient peaks. A field test with dual-source was conducted to certify the existence of interaction between adjacent sources. The simulation of output current also shows that current errors at low frequency are mainly caused by the mutual resistance while those at high frequency are mainly due to the mutual inductance. Increasing the distance between neighboring sources is a proposed measure to reduce the emission signal errors with designed ones. The feasible distance is discussed in the end. This study gives a useful guidance to lay multi sources to meet the requirement of measurement accuracy in FSAEM survey. PMID:27036795

  16. ON THE WIND-INDUCED EXCHANGE BETWEEN INDIAN RIVER BAY, DELAWARE AND THE ADJACENT CONTINENTAL SHELF. (R826945)

    EPA Science Inventory

    The structure of the wind-induced exchange between Indian River Bay, Delaware and the adjacent continental shelf is examined based on current measurements made at the Indian River Inlet which represents the only conduit of exchange between the bay and the coastal ocean. Local ...

  17. 38. VIEW OF COTTRELL MAGNETIC IMPULSE GENERATOR ADJACENT TO SIX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. VIEW OF COTTRELL MAGNETIC IMPULSE GENERATOR ADJACENT TO SIX GAP ROTARY RECTIFIER. THIS UNIT GENERATED A MAGNETIC PULSE WHICH WAS TRANSMITTED TO THE COLLECTION PLATES IN THE ELECTROSTATIC PRECIPITATOR CHAMBER. THESE PERIODIC PULSES VIBRATE THE PLATES AND CAUSE PRECIPITATED ARTICLES OF SMOKE AND FLY ASH TO FALL TO THE BOTTOM OF THE PRECIPITATOR CHAMBER. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  18. Conference room 211, adjacent to commander's quarters, with vault door ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Conference room 211, adjacent to commander's quarters, with vault door at right. Projection area at center is equipped with automatic security drapes. Projection room uses a 45 degree mirror to reflect the image onto the frosted glass screen. Door on far left leads to display area senior battle staff viewing bridge, and the commander's quarters - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  19. Epithelial dysplasia immediately adjacent to oral squamous cell carcinomas.

    PubMed

    Wright, A; Shear, M

    1985-08-01

    A number of workers have attempted to identify dysplastic features which may be predictors of malignant change, by prospective studies of dysplastic lesions. In the present study we have looked at dysplastic changes immediately adjacent to established squamous carcinomas in an attempt to determine whether any predictors can be identified in this way. Eighty cases were included in the study for whom information on tobacco usage was known. Clinical details were recorded. Histological features in epithelium immediately adjacent to the carcinoma were studied in representative sections. Eighteen specific histological characteristics were noted as present or absent. Data were transferred by Conversational Monitoring System (CMS) terminal, processed and analyzed by the Statistical Analysis System (SAS) Computer package. Only 8 patients were non-smokers (10%). Dysplastic changes in adjacent epithelium were frequently multicentric. Changes appear to occur first in the basal layer in the form of disturbance of polarity or basal cell hyperplasia, while other dysplastic features are absent. The feature referred to as basal cell hyperplasia appears, in fact, to represent disturbed epithelial maturation. In 80% of cases increased nucleo-cytoplasmic ratio appears to result from a decrease in cytoplasmic volume rather than increased nuclear size. A defect in RNA synthesis may be a factor. A sharp decrease in inflammatory cells in the lamina propria of adjacent epithelium, compared with that of the carcinoma, was observed. Russell bodies were noted in 5 of the 8 lesions in non-smokers (63%) and in 16 of 72 lesions in smokers (22%) (p less than 0.001; Chi2 17.65). PMID:3928850

  20. 20. Interior view of fuel storage pit or vault adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Interior view of fuel storage pit or vault adjacent to Test Cell 9 in Component Test Laboratory (T-27), looking west. Photograph shows upgraded instrumentation, piping, tanks, and technological modifications installed in 1997-99 to accommodate component testing requirements for the Atlas V missile. - Air Force Plant PJKS, Systems Integration Laboratory, Components Test Laboratory, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  1. FMRI evidence of acupoints specificity in two adjacent acupoints.

    PubMed

    Liu, Hua; Xu, Jian-Yang; Li, Lin; Shan, Bao-Ci; Nie, Bin-Bin; Xue, Jing-Quan

    2013-01-01

    Objectives. Acupoint specificity is the foundation of acupuncture treatment. The aim of this study is to investigate whether the acupoint specificity exists in two adjacent acupoints. Design and Setting. Two adjacent real acupoints, LR3 (Taichong) and ST44 (Neiting), and a nearby nonacupoint were selected. Thirty-three health volunteers were divided into three groups in random order, and each group only received acupuncture at one of the three points. While they received acupuncture, fMRI scan was performed. Results. The common cerebral activated areas responding to LR3 and ST44 included the contralateral primary somatosensory area (SI) and ipsilateral cerebellum. Acupuncture at LR3 specifically activated contralateral middle occipital gyrus, ipsilateral medial frontal gyrus, superior parietal lobe, middle temporal gyrus, rostral anterior cingulate cortex (rACC), lentiform nucleus, insula, and contralateral thalamus. Stimulation at ST44 selectively activated ipsilateral secondary somatosensory area (SII), contralateral middle frontal gyrus, inferior frontal gyrus, lingual gyrus, lentiform nucleus, and bilateral posterior cingulate cortex (PCC). Conclusions. Acupuncture at adjacent acupoints elicits distinct cerebral activation patterns, and those specific patterns might be involved in the mechanism of the specific therapeutic effects of different acupoints. PMID:23762172

  2. Divergent viral presentation among human tumors and adjacent normal tissues.

    PubMed

    Cao, Song; Wendl, Michael C; Wyczalkowski, Matthew A; Wylie, Kristine; Ye, Kai; Jayasinghe, Reyka; Xie, Mingchao; Wu, Song; Niu, Beifang; Grubb, Robert; Johnson, Kimberly J; Gay, Hiram; Chen, Ken; Rader, Janet S; Dipersio, John F; Chen, Feng; Ding, Li

    2016-01-01

    We applied a newly developed bioinformatics system called VirusScan to investigate the viral basis of 6,813 human tumors and 559 adjacent normal samples across 23 cancer types and identified 505 virus positive samples with distinctive, organ system- and cancer type-specific distributions. We found that herpes viruses (e.g., subtypes HHV4, HHV5, and HHV6) that are highly prevalent across cancers of the digestive tract showed significantly higher abundances in tumor versus adjacent normal samples, supporting their association with these cancers. We also found three HPV16-positive samples in brain lower grade glioma (LGG). Further, recurrent HBV integration at the KMT2B locus is present in three liver tumors, but absent in their matched adjacent normal samples, indicating that viral integration induced host driver genetic alterations are required on top of viral oncogene expression for initiation and progression of liver hepatocellular carcinoma. Notably, viral integrations were found in many genes, including novel recurrent HPV integrations at PTPN13 in cervical cancer. Finally, we observed a set of HHV4 and HBV variants strongly associated with ethnic groups, likely due to viral sequence evolution under environmental influences. These findings provide important new insights into viral roles of tumor initiation and progression and potential new therapeutic targets. PMID:27339696

  3. Osteochondroma of the hip with adjacent bursal chondromatosis.

    PubMed

    Gould, Elaine S; Baker, Kevin S; Huang, Mingqian; Khan, Fazel; Hoda, Syed

    2014-12-01

    It is well established that irregular bursae can form adjacent to an osteochondroma (bursa exostotica) as a result of mechanical irritation and that these bursae can be complicated by inflammation, hemorrhage, or infection. Bursal chondromatosis is a rare complication, with only seven published cases in the literature according to our searches. We present the case of a 53-year-old female who presented with slowly progressive left hip/thigh pain and was found to have an osteochondroma arising from the lesser trochanter with numerous ossified bodies in the adjacent soft tissues. MRI demonstrated osteochondral bodies in a fluid-filled bursa adjacent to the osteochondroma, with several of the bodies noted to be fairly displaced from the osteochondroma cartilaginous cap. At surgery, the osteochondroma was removed and numerous bodies of varying sizes were excised, some of which were noted to be adherent to the bursal lining and others that were separated/distant from the cartilage cap. The question arises as to whether this process represents bursal chondromatosis resulting from benign neoplasia of cells lining the abnormal bursa, "cartilage shedding" from the osteochondromatous cap, or both. The purpose in presenting this case is to introduce a rare complication of an osteochondroma, demonstrate that soft tissue calcification and osteochondral densities displaced from an underlying osteochondroma are not always the result of sarcomatous degeneration, and provide support for the theory that cells lining a bursa in a nonphysiologic location can undergo benign neoplasia with subsequent formation of osteochondral bodies. PMID:25001874

  4. Divergent viral presentation among human tumors and adjacent normal tissues

    PubMed Central

    Cao, Song; Wendl, Michael C.; Wyczalkowski, Matthew A.; Wylie, Kristine; Ye, Kai; Jayasinghe, Reyka; Xie, Mingchao; Wu, Song; Niu, Beifang; Grubb, Robert; Johnson, Kimberly J.; Gay, Hiram; Chen, Ken; Rader, Janet S.; Dipersio, John F.; Chen, Feng; Ding, Li

    2016-01-01

    We applied a newly developed bioinformatics system called VirusScan to investigate the viral basis of 6,813 human tumors and 559 adjacent normal samples across 23 cancer types and identified 505 virus positive samples with distinctive, organ system- and cancer type-specific distributions. We found that herpes viruses (e.g., subtypes HHV4, HHV5, and HHV6) that are highly prevalent across cancers of the digestive tract showed significantly higher abundances in tumor versus adjacent normal samples, supporting their association with these cancers. We also found three HPV16-positive samples in brain lower grade glioma (LGG). Further, recurrent HBV integration at the KMT2B locus is present in three liver tumors, but absent in their matched adjacent normal samples, indicating that viral integration induced host driver genetic alterations are required on top of viral oncogene expression for initiation and progression of liver hepatocellular carcinoma. Notably, viral integrations were found in many genes, including novel recurrent HPV integrations at PTPN13 in cervical cancer. Finally, we observed a set of HHV4 and HBV variants strongly associated with ethnic groups, likely due to viral sequence evolution under environmental influences. These findings provide important new insights into viral roles of tumor initiation and progression and potential new therapeutic targets. PMID:27339696

  5. Using BRDFs for accurate albedo calculations and adjacency effect corrections

    SciTech Connect

    Borel, C.C.; Gerstl, S.A.W.

    1996-09-01

    In this paper the authors discuss two uses of BRDFs in remote sensing: (1) in determining the clear sky top of the atmosphere (TOA) albedo, (2) in quantifying the effect of the BRDF on the adjacency point-spread function and on atmospheric corrections. The TOA spectral albedo is an important parameter retrieved by the Multi-angle Imaging Spectro-Radiometer (MISR). Its accuracy depends mainly on how well one can model the surface BRDF for many different situations. The authors present results from an algorithm which matches several semi-empirical functions to the nine MISR measured BRFs that are then numerically integrated to yield the clear sky TOA spectral albedo in four spectral channels. They show that absolute accuracies in the albedo of better than 1% are possible for the visible and better than 2% in the near infrared channels. Using a simplified extensive radiosity model, the authors show that the shape of the adjacency point-spread function (PSF) depends on the underlying surface BRDFs. The adjacency point-spread function at a given offset (x,y) from the center pixel is given by the integral of transmission-weighted products of BRDF and scattering phase function along the line of sight.

  6. Investigation of Threshold Voltage Disturbance Caused by Programmed Adjacent Cell in Virtual Source/Drain NAND Flash Memory

    NASA Astrophysics Data System (ADS)

    Kim, Wandong; Kwon, Dae Woong; Ji, Jung Hwan; Lee, Jung Hoon; Lee, Jong-Ho; Shin, Hyungcheol; Park, Byung-Gook

    2011-04-01

    In this paper, we investigate the threshold voltage disturbance caused by programmed adjacent cells in virtual source/drain (VSD) NAND flash memory device. The fringing field induced by charge in an adjacent memory node inhibits the inversion of virtual source/drain region. So, it increases the threshold voltage of the read cell. This is a drawback for the multi-level cell (MLC) operation. The device simulation and measurement data of fabricated devices show that the disturbance increases as the cell gate length and VSD length decreases. It can be minimized by the electric field concentration induced by the arch shape structure.

  7. Can electromagnetic fields influence the structure and enzymatic digest of proteins? A critical evaluation of microwave-assisted proteomics protocols

    PubMed Central

    Damm, Markus; Nusshold, Christoph; Cantillo, David; Rechberger, Gerald N.; Gruber, Karl; Sattler, Wolfgang; Kappe, C. Oliver

    2012-01-01

    This study reevaluates the putative advantages of microwave-assisted tryptic digests compared to conventionally heated protocols performed at the same temperature. An initial investigation of enzyme stability in a temperature range of 37–80 °C demonstrated that trypsin activity declines sharply at temperatures above 60 °C, regardless if microwave dielectric heating or conventional heating is employed. Tryptic digests of three proteins of different size (bovine serum albumin, cytochrome c and β-casein) were thus performed at 37 °C and 50 °C using both microwave and conventional heating applying accurate internal fiber-optic probe reaction temperature measurements. The impact of the heating method on protein degradation and peptide fragment generation was analyzed by SDS-PAGE and MALDI-TOF-MS. Time-dependent tryptic digestion of the three proteins and subsequent analysis of the corresponding cleavage products by MALDI-TOF provided virtually identical results for both microwave and conventional heating. In addition, the impact of electromagnetic field strength on the tertiary structure of trypsin and BSA was evaluated by molecular mechanics calculations. These simulations revealed that the applied field in a typical laboratory microwave reactor is 3–4 orders of magnitude too low to induce conformational changes in proteins or enzymes. PMID:22889711

  8. NuMA-microtubule interactions are critical for spindle orientation and the morphogenesis of diverse epidermal structures.

    PubMed

    Seldin, Lindsey; Muroyama, Andrew; Lechler, Terry

    2016-01-01

    Mitotic spindle orientation is used to generate cell fate diversity and drive proper tissue morphogenesis. A complex of NuMA and dynein/dynactin is required for robust spindle orientation in a number of cell types. Previous research proposed that cortical dynein/dynactin was sufficient to generate forces on astral microtubules (MTs) to orient the spindle, with NuMA acting as a passive tether. In this study, we demonstrate that dynein/dynactin is insufficient for spindle orientation establishment in keratinocytes and that NuMA's MT-binding domain, which targets MT tips, is also required. Loss of NuMA-MT interactions in skin caused defects in spindle orientation and epidermal differentiation, leading to neonatal lethality. In addition, we show that NuMA-MT interactions are also required in adult mice for hair follicle morphogenesis and spindle orientation within the transit-amplifying cells of the matrix. Loss of spindle orientation in matrix cells results in defective differentiation of matrix-derived lineages. Our results reveal an additional and direct function of NuMA during mitotic spindle positioning, as well as a reiterative use of spindle orientation in the skin to build diverse structures. PMID:26765568

  9. NuMA-microtubule interactions are critical for spindle orientation and the morphogenesis of diverse epidermal structures

    PubMed Central

    Seldin, Lindsey; Muroyama, Andrew; Lechler, Terry

    2016-01-01

    Mitotic spindle orientation is used to generate cell fate diversity and drive proper tissue morphogenesis. A complex of NuMA and dynein/dynactin is required for robust spindle orientation in a number of cell types. Previous research proposed that cortical dynein/dynactin was sufficient to generate forces on astral microtubules (MTs) to orient the spindle, with NuMA acting as a passive tether. In this study, we demonstrate that dynein/dynactin is insufficient for spindle orientation establishment in keratinocytes and that NuMA’s MT-binding domain, which targets MT tips, is also required. Loss of NuMA-MT interactions in skin caused defects in spindle orientation and epidermal differentiation, leading to neonatal lethality. In addition, we show that NuMA-MT interactions are also required in adult mice for hair follicle morphogenesis and spindle orientation within the transit-amplifying cells of the matrix. Loss of spindle orientation in matrix cells results in defective differentiation of matrix-derived lineages. Our results reveal an additional and direct function of NuMA during mitotic spindle positioning, as well as a reiterative use of spindle orientation in the skin to build diverse structures. DOI: http://dx.doi.org/10.7554/eLife.12504.001 PMID:26765568

  10. A critical appraisal of the zero-multipole method: Structural, thermodynamic, dielectric, and dynamical properties of a water system

    NASA Astrophysics Data System (ADS)

    Wang, Han; Nakamura, Haruki; Fukuda, Ikuo

    2016-03-01

    We performed extensive and strict tests for the reliability of the zero-multipole (summation) method (ZMM), which is a method for estimating the electrostatic interactions among charged particles in a classical physical system, by investigating a set of various physical quantities. This set covers a broad range of water properties, including the thermodynamic properties (pressure, excess chemical potential, constant volume/pressure heat capacity, isothermal compressibility, and thermal expansion coefficient), dielectric properties (dielectric constant and Kirkwood-G factor), dynamical properties (diffusion constant and viscosity), and the structural property (radial distribution function). We selected a bulk water system, the most important solvent, and applied the widely used TIP3P model to this test. In result, the ZMM works well for almost all cases, compared with the smooth particle mesh Ewald (SPME) method that was carefully optimized. In particular, at cut-off radius of 1.2 nm, the recommended choices of ZMM parameters for the TIP3P system are α ≤ 1 nm-1 for the splitting parameter and l = 2 or l = 3 for the order of the multipole moment. We discussed the origin of the deviations of the ZMM and found that they are intimately related to the deviations of the equilibrated densities between the ZMM and SPME, while the magnitude of the density deviations is very small.

  11. Critical role of CD4 T cells in maintaining lymphoid tissue structure for immune cell homeostasis and reconstitution

    PubMed Central

    Zeng, Ming; Paiardini, Mirko; Engram, Jessica C.; Beilman, Greg J.; Chipman, Jeffrey G.; Schacker, Timothy W.; Silvestri, Guido

    2012-01-01

    Loss of the fibroblastic reticular cell (FRC) network in lymphoid tissues during HIV-1 infection has been shown to impair the survival of naive T cells and limit immune reconstitution after antiretroviral therapy. What causes this FRC loss is unknown. Because FRC loss correlates with loss of both naive CD4 and CD8 T-cell subsets and decreased lymphotoxin-β, a key factor for maintenance of FRC network, we hypothesized that loss of naive T cells is responsible for loss of the FRC network. To test this hypothesis, we assessed the consequences of antibody-mediated depletion of CD4 and CD8 T cells in rhesus macaques and sooty mangabeys. We found that only CD4 T-cell depletion resulted in FRC loss in both species and that this loss was caused by decreased lymphotoxin-β mainly produced by the CD4 T cells. We further found the same dependence of the FRC network on CD4 T cells in HIV-1–infected patients before and after antiretroviral therapy and in other immunodeficiency conditions, such as CD4 depletion in cancer patients induced by chemotherapy and irradiation. CD4 T cells thus play a central role in the maintenance of lymphoid tissue structure necessary for their own homeostasis and reconstitution. PMID:22613799

  12. Critical Zone Observatories (CZOs): Integrating measurements and models of Earth surface processes to improve prediction of landscape structure, function and evolution

    NASA Astrophysics Data System (ADS)

    Chorover, J.; Anderson, S. P.; Bales, R. C.; Duffy, C.; Scatena, F. N.; Sparks, D. L.; White, T.

    2012-12-01

    The "Critical Zone" - that portion of Earth's land surface that extends from the outer periphery of the vegetation canopy to the lower limit of circulating groundwater - has evolved in response to climatic and tectonic forcing throughout Earth's history, but human activities have recently emerged as a major agent of change as well. With funding from NSF, a network of currently six CZOs is being developed in the U.S. to provide infrastructure, data and models that facilitate understanding the evolution, structure, and function of this zone at watershed to grain scales. Each CZO is motivated by a unique set of hypotheses proposed by a specific investigator team, but coordination of cross-site activities is also leading to integration of a common set of multi-disciplinary tools and approaches for cross-site syntheses. The resulting harmonized four-dimensional datasets are intended to facilitate community-wide exploration of process couplings among hydrology, ecology, soil science, geochemistry and geomorphology across the larger (network-scale) parameter space. Such an approach enables testing of the generalizability of findings at a given site, and also of emergent hypotheses conceived independently of an original CZO investigator team. This two-pronged method for developing a network of individual CZOs across a range of watershed systems is now yielding novel observations and models that resolve mechanisms for Critical Zone change occurring on geological to hydrologic time-scales. For example, recent advances include improved understanding of (i) how mass and energy flux as modulated by ecosystem exchange transforms bedrock to structured, soil-mantled and/or erosive landscapes; (ii) how long-term evolution of landscape structure affects event-based hydrologic and biogeochemical response at pore to catchment scales; (iii) how complementary isotopic measurements can be used to resolve pathways and time scales of water and solute transport from canopy to stream, and

  13. Critics and Criticism of Education

    ERIC Educational Resources Information Center

    Ornstein, Allan C.

    1977-01-01

    Radical educational critics, such as Edgar Friedenberg, Paul Goodman, A. S. Neill, John Holt, Jonathan Kozol, Herbert Kohl, James Herndon, and Ivan Illich, have few constructive goals, no strategy for broad change, and a disdain for modernization and compromise. Additionally, these critics, says the author, fail to consider social factors related…

  14. Functional angiocoupling between follicles and adjacent corpus luteum in heifers.

    PubMed

    Ginther, O J; Siddiqui, M A R; Baldrighi, J M

    2016-07-15

    In single ovulating cattle, ipsilateral versus contralateral interovarian relationships refer to a dominant follicle (DF) and CL in the same versus opposite ovaries. The ipsilateral relationship consists of the DF-CL and the devoid (no DF or CL) intraovarian pattern, and the contralateral relationship consists of the DF pattern and the CL pattern. The DF-CL pattern involves positive effects on both the DF and CL when adjacent (≤3-mm apart) versus separated as follows: greater diameter of DF (e.g., 10.5 ± 0.4 vs. 9.0 ± 0.4 mm), greater percentage of the DF wall with color Doppler signals of blood flow (40.2% ± 2.0% vs. 24.5% ± 1.9%), greater cross-sectional area of the CL (2.2 ± 0.1 vs. 1.8 ± 0.2 cm(2)), and greater percentage of the entire CL with blood flow signals (51.8% ± 1.2% vs. 42.5% ± 3.1%). Additional examples of positive coupling are (1) future DF on Day 0 (day of ovulation) is closer to the CL than the future largest subordinate and (2) diameter of growing follicles on Day 0 and the growth rate on Days 0 to 2 are greater for follicles that are adjacent than separated from the CL. An example of a negative intraovarian effect is decreasing diameter and loss of future DF status of a largest follicle when adjacent to a regressing CL. The impact of the continuity of ovarian angioarchitecture during the periovulatory follicular wave was exemplified in 17 of 18 waves by conversion of an ovary with only the preovulatory follicle to the postovulatory DF-CL pattern. Functional angiocoupling from commonality in angioarchitecture of the DF and adjacent CL would account for both the positive two-way coupling between DF and CL during the luteal phase and the negative effect of a regressing CL on an adjacent follicle during luteolysis. PMID:27056414

  15. Sequence-structure correlations in silk: Poly-Ala repeat of N. clavipes MaSp1 is naturally optimized at a critical length scale.

    PubMed

    Bratzel, Graham; Buehler, Markus J

    2012-03-01

    Spider silk is a self-assembling biopolymer that outperforms many known materials in terms of its mechanical performance despite being constructed from simple and inferior building blocks. While experimental studies have shown that the molecular structure of silk has a direct influence on the stiffness, toughness, and failure strength of silk, few molecular-level analyses of the nanostructure of silk assemblies in particular under variations of genetic sequences have been reported. Here we report atomistic-level structures of the MaSp1 protein from the Nephila Clavipes spider dragline silk sequence, obtained using an in silico approach based on replica exchange molecular dynamics (REMD) and explicit water molecular dynamics. We apply this method to study the effects of a systematic variation of the poly-alanine repeat lengths, a parameter controlled by the genetic makeup of silk, on the resulting molecular structure of silk at the nanoscale. Confirming earlier experimental and computational work, a structural analysis reveals that poly-alanine regions in silk predominantly form distinct and orderly β-sheet crystal domains while disorderly regions are formed by glycine-rich repeats that consist of 3(10)-helix type structures and β-turns. Our predictions are directly validated against experimental data based on dihedral angle pair calculations presented in Ramachandran plots combined with an analysis of the secondary structure content. The key result of our study is our finding of a strong dependence of the resulting silk nanostructure depending on the poly-alanine length. We observe that the wildtype poly-alanine repeat length of six residues defines a critical minimum length that consistently results in clearly defined β-sheet nanocrystals. For poly-alanine lengths below six, the β-sheet nanocrystals are not well-defined or not visible at all, while for poly-alanine lengths at and above six, the characteristic nanocomposite structure of silk emerges with no

  16. Use of human lung tissue for studies of structural changes associated with chronic ozone exposure: Opportunities and critical issues

    SciTech Connect

    Lippmann, M.

    1993-12-01

    Definitive information on the chronic effects of exposure to ozone (O{sub 3}) in humans is not available. There is a strong concern that ozone could produce chronic lung damage in humans on the basis that exposures are ubiquitous at levels that produce transient symptoms, function deficits, and lung inflammation in humans and chronic lung damage in laboratory animals. Both prospective and national population surveys suggest an association between chronic O{sub 3} exposure and reduced lung function, and a pilot investigation of autopsied lungs of accident victims in Los Angeles reported an unexpectedly high incidence of disease in the centriacinar region, the lung region known to receive the highest dose of inhaled O{sub 3}. This paper discusses the advantages and limitations of further studies of structural changes in human lung tissue in relation to chronic O{sub 3} exposure. The major advantages of such studies are that (a) measurable effects may be related to realistic chronic exposures, (b) the effects may be described quantitatively and compared directly to those obtained in chronic animal inhalation exposures, and (c) evidence for chronic effects may be obtained much more rapidly than in prospective studies. The major limitations are the difficulties in obtaining sufficient reliable information on residential history, physical activity out-of-doors, and smoking and other confounding exposures to lung irritants from next of kin, and limited availability of adequate air quality data for determining ambient concentrations at places of residence and/or outdoor exercise. The paper also discusses approaches to minimizing these limitations in the design of specific studies. 15 refs.

  17. Structure-Function Analyses of a Staphylococcus epidermidis Autoinducing Peptide Reveals Motifs Critical for AgrC-type Receptor Modulation.

    PubMed

    Yang, Tian; Tal-Gan, Yftah; Paharik, Alexandra E; Horswill, Alexander R; Blackwell, Helen E

    2016-07-15

    Staphylococcus epidermidis is frequently implicated in human infections associated with indwelling medical devices due to its ubiquity in the skin flora and formation of robust biofilms. The accessory gene regulator (agr) quorum sensing (QS) system plays a prominent role in the establishment of biofilms and infection by this bacterium. Agr activation is mediated by the binding of a peptide signal (or autoinducing peptide, AIP) to its cognate AgrC receptor. Many questions remain about the role of QS in S. epidermidis infections, as well as in mixed-microbial populations on a host, and chemical modulators of its agr system could provide novel insights into this signaling network. The AIP ligand provides an initial scaffold for the development of such probes; however, the structure-activity relationships (SARs) for activation of S. epidermidis AgrC receptors by AIPs are largely unknown. Herein, we report the first SAR analyses of an S. epidermidis AIP by performing systematic alanine and d-amino acid scans of the S. epidermidis AIP-I. On the basis of these results, we designed and identified potent, pan-group inhibitors of the AgrC receptors in the three S. epidermidis agr groups, as well as a set of AIP-I analogs capable of selective AgrC inhibition in either specific S. epidermidis agr groups or in another common staphylococcal species, S. aureus. In addition, we uncovered a non-native peptide agonist of AgrC-I that can strongly inhibit S. epidermidis biofilm growth. Together, these synthetic analogs represent new and readily accessible probes for investigating the roles of QS in S. epidermidis colonization and infections. PMID:27159024

  18. Critical laminar shear-temperature effects on the nano- and mesoscale structure of a model fat and its relationship to oil binding and rheological properties.

    PubMed

    Acevedo, Nuria C; Block, Jane M; Marangoni, Alejandro G

    2012-01-01

    This article reports on the effect of laminar shear on structural and mechanical properties of physical mixtures of fully hydrogenated soybean oil (FHSO) in soybean oil (SO). Blends were crystallized statically and under laminar shear rates of 30 and 240 s(-1) at different wall temperatures (-10, 0, 20 degrees C). The micro- and nanocrystalline structures were characterized using Polarized Light Microscopy (PLM), and Cryogenic Transmission Electron Microscopy (Cryo-TEM). Rheological analysis was used to determine changes in mechanical properties. Oil-binding capacity was analyzed through the measurement of the oil lost from the fat samples (OL). Shearing greatly affected the structure at the nano- and mesoscale. At low shear rates, blends displayed the largest increase in crystal size with an increase in wall temperature at both the nano- and mesoscale. On the other hand, at shear rates of 240 s(-1), the effect of crystallization temperature was observed only at the nanoscale since no changes in meso-crystal sizes were observed at different temperatures. Crystallization under laminar shear promoted the growth of spherical crystalline particles at the mesoscale, called here "solid-lipid meso-particles". Crystallization under higher shear rates led to the formation of a weak network with low oil-binding capacity and promoted the asymmetric growth of nanoplatelets. In statically crystallized blends, nanoplatelets had an aspect ratio of -2, while in sheared blends this value increased significantly. These results revealed the existence of critical shear rate values above which strong alterations in the structure of the solid crystalline network took place. Shearing also affected the material's strength. Laminar shear induced a decrease in elastic modulus and yield stress values which was more pronounced at higher shear rate-temperature combinations. Shear-temperature combinations were successfully used to structure fats at the nano and mesoscale. PMID:23234167

  19. Lance water injection tests adjacent to the 281-3H retention basin at the Savannah River Site, Aiken, South Carolina

    SciTech Connect

    Freifeld, B.; Myer, L.; Moridis, G.; Cook, P.; James, A.; Pellerin, L.; Pruess, K.

    1996-09-01

    A pilot-scale field demonstration of waste isolation using viscous- liquid containment barriers has been planned for the 281-3H retention basin at the Savannah River Site, Aiken, SC. The 281-3H basin is a shallow retention/seepage basin contaminated mainly by radionuclides. The viscous-liquid containment barrier utilizes the permeation of liquid grout to either entomb the contaminants within a monolithic grout structure or to isolate the waste by drastically reducing the permeability, of the soils around the plume. A clear understanding of the hydrogeologic setting of the retention basin is necessary for proper design of the viscous liquid barrier. To aid in the understanding of the hydrogeology of the 281-3H retention basin, and to obtain critical parameters necessary for grout injection design, a series of tests were undertaken in a region immediately adjacent to the basin. The objectives of the LWIT were: 1. To evaluate the general performance of the Lance Injection Technique for grout emplacement at the site, including the range and upper limits of injection pressures, the flow rates applicable for site conditions, as well as the mechanical forces needed for lance penetration. 2. To obtain detailed information on the injectability of the soils immediately adjacent to the H-area retention basin. 3. To identify any high permeability zones suitable for injection and evaluate their spatial distribution. 4. To perform ground penetrating radar (GPR) to gain information on the structure of the soil column and to compare the results with LWIT data. This report will focus on results pertinent to these objectives.

  20. Bose-Einstein condensation in mesoscopic systems: The self-similar structure of the critical region and the nonequivalence of the canonical and grand canonical ensembles

    NASA Astrophysics Data System (ADS)

    Kocharovsky, V. V.; Kocharovsky, Vl. V.; Tarasov, S. V.

    2016-01-01

    The analytical theory of Bose-Einstein condensation of an ideal gas in mesoscopic systems has been briefly reviewed in application to traps with arbitrary shapes and dimension. This theory describes the phases of the classical gas and the formed Bose-Einstein condensate, as well as the entire vicinity of the phase transition point. The statistics and thermodynamics of Bose-Einstein condensation have been studied in detail, including their self-similar structure in the critical region, transition to the thermodynamic limit, effect of boundary conditions on the properties of a system, and nonequivalence of the description of Bose-Einstein condensation in different statistical ensembles. The complete classification of universality classes of Bose-Einstein condensation has been given.

  1. The NMR structure of the II-III-VI three-way junction from the Neurospora VS ribozyme reveals a critical tertiary interaction and provides new insights into the global ribozyme structure.

    PubMed

    Bonneau, Eric; Girard, Nicolas; Lemieux, Sébastien; Legault, Pascale

    2015-09-01

    As part of an effort to structurally characterize the complete Neurospora VS ribozyme, NMR solution structures of several subdomains have been previously determined, including the internal loops of domains I and VI, the I/V kissing-loop interaction and the III-IV-V junction. Here, we expand this work by determining the NMR structure of a 62-nucleotide RNA (J236) that encompasses the VS ribozyme II-III-VI three-way junction and its adjoining stems. In addition, we localize Mg(2+)-binding sites within this structure using Mn(2+)-induced paramagnetic relaxation enhancement. The NMR structure of the J236 RNA displays a family C topology with a compact core stabilized by continuous stacking of stems II and III, a cis WC/WC G•A base pair, two base triples and two Mg(2+) ions. Moreover, it reveals a remote tertiary interaction between the adenine bulges of stems II and VI. Additional NMR studies demonstrate that both this bulge-bulge interaction and Mg(2+) ions are critical for the stable folding of the II-III-VI junction. The NMR structure of the J236 RNA is consistent with biochemical studies on the complete VS ribozyme, but not with biophysical studies performed with a minimal II-III-VI junction that does not contain the II-VI bulge-bulge interaction. Together with previous NMR studies, our findings provide important new insights into the three-dimensional architecture of this unique ribozyme. PMID:26124200

  2. The NMR structure of the II–III–VI three-way junction from the Neurospora VS ribozyme reveals a critical tertiary interaction and provides new insights into the global ribozyme structure

    PubMed Central

    Bonneau, Eric; Girard, Nicolas; Lemieux, Sébastien; Legault, Pascale

    2015-01-01

    As part of an effort to structurally characterize the complete Neurospora VS ribozyme, NMR solution structures of several subdomains have been previously determined, including the internal loops of domains I and VI, the I/V kissing-loop interaction and the III–IV–V junction. Here, we expand this work by determining the NMR structure of a 62-nucleotide RNA (J236) that encompasses the VS ribozyme II–III–VI three-way junction and its adjoining stems. In addition, we localize Mg2+-binding sites within this structure using Mn2+-induced paramagnetic relaxation enhancement. The NMR structure of the J236 RNA displays a family C topology with a compact core stabilized by continuous stacking of stems II and III, a cis WC/WC G•A base pair, two base triples and two Mg2+ ions. Moreover, it reveals a remote tertiary interaction between the adenine bulges of stems II and VI. Additional NMR studies demonstrate that both this bulge–bulge interaction and Mg2+ ions are critical for the stable folding of the II–III–VI junction. The NMR structure of the J236 RNA is consistent with biochemical studies on the complete VS ribozyme, but not with biophysical studies performed with a minimal II–III–VI junction that does not contain the II–VI bulge–bulge interaction. Together with previous NMR studies, our findings provide important new insights into the three-dimensional architecture of this unique ribozyme. PMID:26124200

  3. The genesis of Typhoon Nuri as observed during the Tropical Cyclone Structure 2008 (TCS-08) field experiment - Part 1: The role of the easterly wave critical layer

    NASA Astrophysics Data System (ADS)

    Montgomery, M. T.; Lussier, L. L., III; Moore, R. W.; Wang, Z.

    2010-10-01

    An observational and real-time model forecast study of the genesis of Typhoon Nuri during the Tropical Cyclone Structure 2008 (TCS-08) field campaign in the western North Pacific sector is presented. Analysis and observational data show that the surrounding base state is an easterly trade wind flow and the precursor disturbance to Typhoon Nuri is an easterly wave that originates in the ITCZ in the Central Pacific. This disturbance can be tracked more than 10 days prior to tropical storm formation. An overview of the field data is presented here using a newly proposed dynamical framework for tropical cyclone formation within the critical layer of an easterly wave. Despite propagating through a hostile environment ripe with strong vertical wind shear and relatively dry air, the easterly wave critical layer protects the proto-vortex and allows it to gestate until it reaches a more favorable environment. Within this protective "Kelvin cat's eye flow" located within the wave's critical layer existed a sweet spot, defined as the intersection between the wave trough and critical latitude, which is the preferred location for tropical cyclogenesis. Global Forecast System Final Analyses and IR satellite imagery, which shows convective bands wrapping around the sweet spot as genesis nears, confirm that this sweet spot is the location where Typhoon Nuri's dominant low-level circulation emerges. United States Air Force C130 and Naval Research Laboratory P3 research flights on 16 and 17 August collected flight-level, dropwindsonde, and Doppler radar data that allowed an evaluation of the dynamic and thermodynamic processes within the cat's eye circulation. The dropwindsonde analyses identifies the precursor easterly wave disturbance on 16 August and identifies an area of weak low-level cyclonic circulation on 17 August. Real-time forecasts were produced using operational global prediction model data to support scientific missions during TCS-08. These forecasts were found to be

  4. The genesis of Typhoon Nuri as observed during the Tropical Cyclone Structure 2008 (TCS-08) field experiment - Part 1: The role of the easterly wave critical layer

    NASA Astrophysics Data System (ADS)

    Montgomery, M. T.; Lussier, L. L., III; Moore, R. W.; Wang, Z.

    2009-09-01

    An observational and real-time model forecast study of the genesis of Typhoon Nuri during the Tropical Cyclone Structure 2008 (TCS-08) field campaign in the western North Pacific sector is presented. Analysis and observational data show that the surrounding base state flow was an easterly trade wind flow and the precursor disturbance to Typhoon Nuri was an easterly wave that originated in the ITCZ in the Central Pacific and can be tracked more than 10 days prior to tropical storm formation. An overview of the field data is presented here using a newly proposed dynamical framework for tropical cyclone formation within the critical layer of an easterly wave. Despite propagating through a hostile environment ripe with strong vertical wind shear and relatively dry air, the easterly wave critical layer protected the proto-vortex and allowed it to gestate until it reached a more favorable environment. Within this protective "Kelvin's cat's eye flow" located within the wave's critical layer existed a "sweet spot", defined as the intersection between the wave trough and critical latitude, which was the preferred location for tropical cyclogenesis. Global Forecast System Final Analyses and IR satellite imagery, which shows convective bands wrapping around the sweet spot as genesis nears, confirm that this sweet spot is the location where Typhoon Nuri's dominant low-level circulation emerges. United States Air Force C130 and Naval Research Laboratory P3 research flights on 16 and 17 August collected flight-level, dropwindsonde, and Doppler radar data that allowed an evaluation of the dynamic and thermodynamic processes within the cat's eye. The dropwindsonde analyses identified the precursor easterly wave disturbance on 16 August and identified an area of weak low-level cyclonic circulation on 17 August. During the TCS-08 experiment "real-time forecasts" were produced in real-time using operational global prediction model data to support scientific missions. These forecasts

  5. Adjacent central venous catheters can result in immediate aspiration of infused drugs during renal replacement therapy.

    PubMed

    Kam, K Y R; Mari, J M; Wigmore, T J

    2012-02-01

    Dual-lumen haemodiafiltration catheters enable continuous renal replacement therapy in the critically ill and are often co-located with central venous catheters used to infuse drugs. The extent to which infusions are immediately aspirated by an adjacent haemodiafiltration catheter remains unknown. A bench model was constructed to evaluate this effect. A central venous catheter and a haemodiafiltration catheter were inserted into a simulated central vein and flow generated using centrifugal pumps within the simulated vein and haemodiafiltration circuit. Ink was used as a visual tracer and creatinine solution as a quantifiable tracer. Tracers were completely aspirated by the haemodiafiltration catheter unless the infusion was at least 1 cm downstream to the arterial port. No tracer was aspirated from catheters infusing at least 2 cm downstream. Orientation of side ports did not affect tracer elimination. Co-location of central venous and haemodiafiltration catheters may lead to complete aspiration of infusions into the haemodiafilter with resultant drug under-dosing. PMID:22059378

  6. Impact of adjacent land use on coastal wetland sediments.

    PubMed

    Karstens, Svenja; Buczko, Uwe; Jurasinski, Gerald; Peticzka, Robert; Glatzel, Stephan

    2016-04-15

    Coastal wetlands link terrestrial with marine ecosystems and are influenced from both land and sea. Therefore, they are ecotones with strong biogeochemical gradients. We analyzed sediment characteristics including macronutrients (C, N, P, K, Mg, Ca, S) and heavy metals (Mn, Fe, Cu, Zn, Al, Co, Cr, Ni) of two coastal wetlands dominated by Phragmites australis at the Darss-Zingst Bodden Chain, a lagoon system at the Southern Baltic Sea, to identify the impact of adjacent land use and to distinguish between influences from land or sea. In the wetland directly adjacent to cropland (study site Dabitz) heavy metal concentrations were significantly elevated. Fertilizer application led to heavy metal accumulation in the sediments of the adjacent wetland zones. In contrast, at the other study site (Michaelsdorf), where the hinterland has been used as pasture, heavy metal concentrations were low. While the amount of macronutrients was also influenced by vegetation characteristics (e.g. carbon) or water chemistry (e.g. sulfate), the accumulation of heavy metals is regarded as purely anthropogenic influence. A principal component analysis (PCA) based on the sediment data showed that the wetland fringes of the two study sites are not distinguishable, neither in their macronutrient status nor in their concentrations of heavy metals, whereas the interior zones exhibit large differences in terms of heavy metal concentrations. This suggests that seaside influences are minor compared to influences from land. Altogether, heavy metal concentrations were still below national precautionary and action values. However, if we regard the macronutrient and heavy metal concentrations in the wetland fringes as the natural background values, an accumulation of trace elements from agricultural production in the hinterland is apparent. Thus, coastal wetlands bordering croplands may function as effective pollutant buffers today, but the future development has to be monitored closely to avoid

  7. Structure of an outer surface lipoprotein BBA64 from the Lyme disease agent Borrelia burgdorferi which is critical to ensure infection after a tick bite.

    PubMed

    Brangulis, Kalvis; Tars, Kaspars; Petrovskis, Ivars; Kazaks, Andris; Ranka, Renate; Baumanis, Viesturs

    2013-06-01

    Lyme disease is a tick-borne infection caused by the transmission of Borrelia burgdorferi from infected Ixodes ticks to a mammalian host during the blood meal. Previous studies have shown that the expression of B. burgdorferi surface-localized lipoproteins, which include BBA64, is up-regulated during the process of tick feeding. Although the exact function of BBA64 is not known, this lipoprotein is critical for the transmission of the spirochete from the tick salivary glands to the mammalian organism after a tick bite. Since the mechanism of development of the disease and the functions of the surface lipoproteins associated with borreliosis are still poorly understood, the crystal structure of the B. burgdorferi outer surface lipoprotein BBA64 was solved at 2.4 Å resolution in order to obtain a better insight into the pathogenesis of B. burgdorferi and to promote the discovery of novel potential preventive drugs against Lyme disease. In this study, the crystal structure of BBA64 was also compared with that of the paralogous protein CspA (also referred to as BbCRASP-1, CRASP-1 or BBA68). CspA is the complement regulator-acquiring surface protein-1 of B. burgdorferi; its structure is known, but its function apparently differs from that of BBA64. It is demonstrated that unlike the homologous CspA, BBA64 does not form a homodimer. Their differences in function could be explained by divergence in their amino-acid sequences, electrostatic surface potentials and overall tertiary structures. The C-terminal part of BBA64 has a different conformation to that of CspA; the conformation of this region is essential for the proper function of CspA. PMID:23695254

  8. Structure-activity relations of leucine derivatives reveal critical moieties for cellular uptake and activation of mTORC1-mediated signaling.

    PubMed

    Nagamori, Shushi; Wiriyasermkul, Pattama; Okuda, Suguru; Kojima, Naoto; Hari, Yoshiyuki; Kiyonaka, Shigeki; Mori, Yasuo; Tominaga, Hideyuki; Ohgaki, Ryuichi; Kanai, Yoshikatsu

    2016-04-01

    Among amino acids, leucine is a potential signaling molecule to regulate cell growth and metabolism by activating mechanistic target of rapamycin complex 1 (mTORC1). To reveal the critical structures of leucine molecule to activate mTORC1, we examined the structure-activity relationships of leucine derivatives in HeLa S3 cells for cellular uptake and for the induction of phosphorylation of p70 ribosomal S6 kinase 1 (p70S6K), a downstream effector of mTORC1. The activation of mTORC1 by leucine and its derivatives was the consequence of two successive events: the cellular uptake by L-type amino acid transporter 1 (LAT1) responsible for leucine uptake in HeLa S3 cells and the activation of mTORC1 following the transport. The structural requirement for the recognition by LAT1 was to have carbonyl oxygen, alkoxy oxygen of carboxyl group, amino group and hydrophobic side chain. In contrast, the requirement for mTORC1 activation was more rigorous. It additionally required fixed distance between carbonyl oxygen and alkoxy oxygen of carboxyl group, and amino group positioned at α-carbon. L-Configuration in chirality and appropriate length of side chain with a terminal isopropyl group were also important. This confirmed that LAT1 itself is not a leucine sensor. Some specialized leucine sensing mechanism with rigorous requirement for agonistic structures should exist inside the cells because leucine derivatives not transported by LAT1 did not activate mTORC1. Because LAT1-mTOR axis is involved in the regulation of cell growth and cancer progression, the results from this study may provide a new insight into therapeutics targeting both LAT1 and leucine sensor. PMID:26724922

  9. Dynamic networks community detection via low rank component recovery of adjacency matrices

    NASA Astrophysics Data System (ADS)

    Bao, Wei; Michailidis, George

    Dynamic community detection in networks has been of high interest due to its various applications. In this work, we apply low rank extraction technique on adjacency matrices to approximate the community structures. Not only can we accurately identify the phase transition time points where significant changes in the community structures occur, but also we can increase the accuracy of the core community structures recovered in the `peace' time ranges by averaging the low rank components. A systematic methodology has been proposed as how to accomplish the target. Factor model, and stochastic block model (including weighted scenario) have been tested for the robustness of our model. Besides, applications on both Kuramoto model and US Senate Roll Call data are also carried out and interesting results are obtained.

  10. Exophytic Atheroma Mimicking Papillary Fibroelastoma Adjacent to the Aortic Valve.

    PubMed

    Cho, Tomoki; Tokunaga, Shigehiko; Yasuda, Shota; Izubuchi, Ryo; Masuda, Munetaka

    2015-09-01

    Follow-up echocardiography in a 69-year-old man with alcoholic cardiomyopathy showed a mass above the aortic valve near the left coronary ostium. Transesophageal echocardiography and computed tomography suggested a papillary fibroelastoma with a high risk of embolism. At operation we found an exophytic atheroma adjacent to the left coronary artery orifice. The atheroma was removed, and the patient made an uneventful recovery. We describe this very rare case of an exophytic atheroma mimicking a papillary fibroelastoma situated at the left coronary orifice. PMID:26354633

  11. Synthesis of a Molecule with Four Different Adjacent Pnictogens.

    PubMed

    Hinz, Alexander; Schulz, Axel; Villinger, Alexander

    2016-08-22

    The synthesis of a molecule containing four adjacent different pnictogens was attempted by conversion of a Group 15 allyl analogue anion [Mes*NAsPMes*](-) (Mes*=2,4,6-tri-tert-butylphenyl) with antimony(III) chloride. A suitable precursor is Mes*N(H)AsPMes* (1) for which several syntheses were investigated. The anions afforded by deprotonation of Mes*N(H)AsPMes* were found to be labile and, therefore, salts could not be isolated. However, the in situ generated anions could be quenched with SbCl3 , yielding Mes*N(SbCl2 )AsPMes* (4). PMID:27377437

  12. Stereoselective Organocatalytic Synthesis of Oxindoles with Adjacent Tetrasubstituted Stereocenters.

    PubMed

    Engl, Oliver D; Fritz, Sven P; Wennemers, Helma

    2015-07-01

    Oxindoles with adjacent tetrasubstituted stereocenters were obtained in high yields and stereoselectivities by organocatalyzed conjugate addition reactions of monothiomalonates (MTMs) to isatin-derived N-Cbz ketimines. The method requires only a low catalyst loading (2 mol %) and proceeds under mild reaction conditions. Both enantiomers are accessible in good yields and excellent stereoselectivities by using either Takemoto's catalyst or a cinchona alkaloid derivative. The synthetic methodology allowed establishment of a straightforward route to derivatives of the gastrin/cholecystokinin-B receptor antagonist AG-041R. PMID:26033441

  13. Interaction of Cracks Between Two Adjacent Indents in Glass

    NASA Technical Reports Server (NTRS)

    Choi, S. R.; Salem, J. A.

    1993-01-01

    Experimental observations of the interaction behavior of cracks between two adjacent indents were made using an indentation technique in soda-lime glass. It was specifically demonstrated how one indent crack initiates and propagates in the vicinity of another indent crack. Several types of crack interactions were examined by changing the orientation and distance of one indent relative to the other. It was found that the residual stress field produced by elastic/plastic indentation has a significant influence on controlling the mode of crack interaction. The interaction of an indent crack with a free surface was also investigated for glass and ceramic specimens.

  14. CLOUD PEAK PRIMITIVE AREA AND ADJACENT AREAS, WYOMING.

    USGS Publications Warehouse

    Kiilsgaard, Thor H.; Patten, Lowell L.

    1984-01-01

    The results of a mineral survey of the Cloud Peak Primitive Area and adjacent areas in Wyoming indicated little promise for the occurrence of mineral resources. There are some prospect workings, particularly in the northern part of the area, but in none of them were there indications that ore had been mined. Samples from the workings, from nearby rocks and sediments from streams that drain the area did not yield any metal values of significance. The crystalline rocks that underlie the area do not contain oil and gas or coal, products that are extracted from the younger rocks that underlie basins on both sides of the study area.

  15. Drivers of tall shrub proliferation adjacent to the Dempster Highway, Northwest Territories, Canada

    NASA Astrophysics Data System (ADS)

    Cameron, Emily A.; Lantz, Trevor C.

    2016-04-01

    Arctic ecosystems are undergoing rapid changes as a result of climate warming and more frequent disturbances. Disturbances can have particularly large effects on high-latitude ecosystems when ecosystem structure and function is controlled by strong feedbacks between soil conditions, vegetation, and ground thermal regime. In this study we investigated the impact of road construction and maintenance on vegetation structure and biomass along the Dempster Highway where it crosses the Peel Plateau in the Northwest Territories. To explore drivers of tall shrub proliferation and to quantify shrub proliferation in this region of continuous permafrost, greyscale air photos (1975) and Quickbird satellite imagery (2008) were used to map landcover change within two 0.6 km2 belts next to the road and two 0.6 km2 belts 500 m away from the road. Maps showing areas where: 1) tall shrubs expanded, and 2) dwarf shrub tundra resisted invasion were then used to select field sites where a suite of biophysical variables were measured. Rapid tall shrub proliferation and greater biomass adjacent to the road indicate that disturbance can facilitate vegetation change in tundra environments. Our field data also suggests that increased shrub proliferation adjacent to the road was caused by greater soil moisture. Tall shrub proliferation adjacent to the road occurred at lower elevation sites characterized by wetter soils with thicker organic layers. Areas that resisted tall shrub encroachment were located at higher elevations and had drier soils with thin organic layers. Our observations also support previous work illustrating that tall shrub expansion next to the highway promotes strong positive feedbacks to ongoing shrub growth and proliferation.

  16. Geology of the Cape Mendocino, Eureka, Garberville, and Southwestern Part of the Hayfork 30 x 60 Minute Quadrangles and Adjacent Offshore Area, Northern California

    USGS Publications Warehouse

    McLaughlin, Robert J.; Ellen, S.D.; Blake, M.C., Jr.; Jayko, Angela S.; Irwin, W.P.; Aalto, K.R.; Carver, G.A.; Clarke, S.H., Jr.; Barnes, J.B.; Cecil, J.D.; Cyr, K.A.

    2000-01-01

    Introduction These geologic maps and accompanying structure sections depict the geology and structure of much of northwestern California and the adjacent continental margin. The map area includes the Mendocino triple junction, which is the juncture of the North American continental plate with two plates of the Pacific ocean basin. The map area also encompasses major geographic and geologic provinces of northwestern California. The maps incorporate much previously unpublished geologic mapping done between 1980 and 1995, as well as published mapping done between about 1950 and 1978. To construct structure sections to mid-crustal depths, we integrate the surface geology with interpretations of crustal structure based on seismicity, gravity and aeromagnetic data, offshore structure, and seismic reflection and refraction data. In addition to describing major geologic and structural features of northwestern California, the geologic maps have the potential to address a number of societally relevant issues, including hazards from earthquakes, landslides, and floods and problems related to timber harvest, wildlife habitat, and changing land use. All of these topics will continue to be of interest in the region, as changing land uses and population density interact with natural conditions. In these interactions, it is critical that the policies and practices affecting man and the environment integrate an adequate understanding of the geology. This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (ceghmf.ps, ceghmf.pdf, ceghmf.txt), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The

  17. Structure and Function of the E. coli Protein YmgB: a Protein Critical for Biofilm Formation and Acid-resistance

    PubMed Central

    Lee, Jintae; Page, Rebecca; García-Contreras, Rodolfo; Palermino, Jeanne-Marie; Zhang, Xue-Song; Doshi, Ojus; Wood, Thomas K.; Peti, Wolfgang

    2007-01-01

    The Escherichia coli gene cluster ymgABC was identified in transcriptome studies to play a role in biofilm development and stability. In this study we show that YmgB represses biofilm formation in rich medium containing glucose, decreases cellular motility, and protects the cell from acid indicating that YmgB plays a major role in acid-resistance in E. coli. Our data also shows that these phenotypes are potentially mediated through interactions with the important cell signal indole. In addition, gel shift assays suggest that YmgB may be a non-specific DNA-binding protein. Using nickel-enrichment DNA microarrays, we show that YmgB binds, either directly or indirectly via a second protein, genes important for biofilm formation. To advance our understanding of the function of YmgB, we used X-ray crystallography to solve the structure of the protein to 1.8 Å resolution. YmgB is a biological dimer that is structurally homologous to the E. coli gene regulatory protein Hha, despite its low sequence identity of only 5%. This supports our DNA microarray data that YmgB is a gene regulatory protein. Therefore, this protein, which clearly has a critical role in acid-resistance in E. coli, has been renamed as AriR for regulator of acid-resistance influenced by indole. PMID:17765265

  18. Structure and Function of the Escherichia coli Protein YmgB: A Protein Critical for Biofilm Formation and Acid-resistance

    SciTech Connect

    Lee,J.; Page, R.; Garcia-Contreras, R.; Palermino, J.; Zhang, X.; Doshi, O.; Wood, T.; Peti, W.

    2007-01-01

    The Escherichia coli gene cluster ymgABC was identified in transcriptome studies to have a role in biofilm development and stability. In this study, we showed that YmgB represses biofilm formation in rich medium containing glucose, decreases cellular motility, and protects the cell from acid indicating that YmgB has a major role in acid-resistance in E. coli. Our data show that these phenotypes are potentially mediated through interactions with the important cell signal indole. In addition, gel mobility-shift assays suggest that YmgB may be a non-specific DNA-binding protein. Using nickel-enrichment DNA microarrays, we showed that YmgB binds, either directly or indirectly, via a probable ligand, genes important for biofilm formation. To advance our understanding of the function of YmgB, we used X-ray crystallography to solve the structure of the protein to 1.8 A resolution. YmgB is a biological dimer that is structurally homologous to the E. coli gene regulatory protein Hha, despite having only 5% sequence identity. This supports our DNA microarray data showing that YmgB is a gene regulatory protein. Therefore, this protein, which clearly has a critical role in acid-resistance in E. coli, has been renamed as AriR for regulator of acid resistance influenced by indole.

  19. Stabilization of endangered part of structures by building dry brunt brick buttressing, critical case study of plane wall in DKG-North Area, Mohenjo daro

    NASA Astrophysics Data System (ADS)

    Shaikh, J. M.; Park, J.

    2013-07-01

    'World Heritage Sites' are places or buildings of outstanding universal value recognized as constituting a world heritage 'for whose protection it is the duty of the international community as a whole to co-operate'. The concept of World Heritage is at the core of the World Heritage Convention, adopted by Heritage List as a means of identifying, protecting, conserving and presenting those parts of the world's natural and cultural heritage that are of sufficient 'outstanding universal value' to be the responsibility of the international community as a whole. By joining the Convention, nation states are pledged to safeguard the WH S by protecting their national heritage. UNESCO in 1972, to which 160 nations have now been adhered. The Convention came into force in 1975 and established a Site in their territory as part of a universally agreed policy for World. Moenjodaro site covering an area of 555 Acres out of which only 10 % of it has been excavated by exposing 50 Kilometer standing walls. The wall of the main street of DK G Area, Mohen jo Daro partially deformed, due to the torque effects this is studied here on a lateral cross wall in the chief house. Furthermore, the resulting behaviour of the bucking wall demonstrates the significant loadbearing capacity of the structure under service conditions and its high sensitivity to imposed changes of the geometry. Although the tensile stresses exceeded the flexural strength at the vertices and the length of the wall, hence both the geometry and condition of this area are critical for the safety of the wall. The results of this study can improve the assessment and thus help in the preservation of many important structures of the metropolitan city. Here the hydrous characteristic of the brick is studied as a general phenomenon, it is observed that the remains of the sites located in Sindh suffered a lot mostly due to age, human neglect variations of atmospheric condition, severe temperature and natural disasters. The main

  20. Image registration using a weighted region adjacency graph

    NASA Astrophysics Data System (ADS)

    Al-Hasan, Muhannad; Fisher, Mark

    2005-04-01

    Image registration is an important problem for image processing and computer vision with many proposed applications in medical image analysis.1, 2 Image registration techniques attempt to map corresponding features between two images. The problem is particularly difficult as anatomy is subject to elastic deformations. This paper considers this problem in the context of graph matching. Firstly, weighted Region Adjacency Graphs (RAGs) are constructed from each image using an approach based on watershed saliency. 3 The vertices of the RAG represent salient regions in the image and the (weighted) edges represent the relationship (bonding) between each region. Correspondences between images are then determined using a weighted graph matching method. Graph matching is considered to be one of the most complex problems in computer vision, due to its combinatorial nature. Our approach uses a multi-spectral technique to graph matching first proposed by Umeyama4 to find an approximate solution to the weighted graph matching problem (WGMP) based on the singular value decomposition of the adjacency matrix. Results show the technique is successful in co-registering 2-D MRI images and the method could be useful in co-registering 3-D volumetric data (e.g. CT, MRI, SPECT, PET etc.).

  1. Stress Wave Interaction Between Two Adjacent Blast Holes

    NASA Astrophysics Data System (ADS)

    Yi, Changping; Johansson, Daniel; Nyberg, Ulf; Beyglou, Ali

    2016-05-01

    Rock fragmentation by blasting is determined by the level and state of stress in the rock mass subjected to blasting. With the application of electronic detonators, some researchers stated that it is possible to achieve improved fragmentation through stress wave superposition with very short delay times. This hypothesis was studied through theoretical analysis in the paper. First, the stress in rock mass induced by a single-hole shot was analyzed with the assumptions of infinite velocity of detonation and infinite charge length. Based on the stress analysis of a single-hole shot, the stress history and tensile stress distribution between two adjacent holes were presented for cases of simultaneous initiation and 1 ms delayed initiation via stress superposition. The results indicated that the stress wave interaction is local around the collision point. Then, the tensile stress distribution at the extended line of two adjacent blast holes was analyzed for a case of 2 ms delay. The analytical results showed that the tensile stress on the extended line increases due to the stress wave superposition under the assumption that the influence of neighboring blast hole on the stress wave propagation can be neglected. However, the numerical results indicated that this assumption is unreasonable and yields contrary results. The feasibility of improving fragmentation via stress wave interaction with precise initiation was also discussed. The analysis in this paper does not support that the interaction of stress waves improves the fragmentation.

  2. Adjacent flaps for lower lip reconstruction after mucocele resection.

    PubMed

    Ying, Binbin

    2012-03-01

    Mucocele forms because of salivary gland mucous extravasation or retention and is usually related to trauma in the area of the lower lip. It is a common benign lesion in the oral region. Although there are many conservative treatments such as the creation of a pouch (marsupialization), freezing (cryosurgery), micromarsupialization, and CO2 laser vaporization, surgical resection is the most commonly used means. Generally speaking, an elliptic incision was made to fully enucleate the lesion along with the overlying mucosa and the affected glands, then direct suturing is adequate. However, in some cases, direct suturing could cause lower lip deformity, and adjacent flaps for lower lip reconstruction after mucocele resection might be quite necessary. Based on our experience, adjacent mucosal flaps could be used when lesions were close to or even break through the vermilion border or their diameters were much more than 1 cm. A-T advancement flaps and transposition flaps were the mostly applied ones. Follow-up showed that all patients realized primary healing after 1 week postoperatively with satisfactory lower lip appearance, and there was no sign of increasing incidence of relapse. PMID:22421867

  3. Historical volcanoes of Armenia and adjacent areas: What is revisited?

    NASA Astrophysics Data System (ADS)

    Karakhanian, A.; Jrbashyan, R.; Trifonov, V.; Philip, H.; Arakelian, S.; Avagyan, A.; Baghdassaryan, H.; Davtian, V.

    2006-07-01

    The validity of some data in Karakhanian et al. [Karakhanian, A., Djrbashian, R., Trifonov V., Philip H., Arakelian S., Avagian, A., 2002. Holocene-historical volcanism and active faults as natural risk factor for Armenia and adjacent countries. Journal of Volcanology and Geothermal Research, 113, 1, 319-344; Karakhanian, A., Jrbashyan, R., Trifonov, V., Philip, H., Arakelian, S., Avagyan, A., Baghdassaryan, H., Davtian, V., Ghoukassyan, Yu., 2003. Volcanic hazards in the region of the Armenian nuclear power plant. Journal of Volcanology and Geothermal Research, 126/1-2, 31-62] that are revisited by R. Haroutiunian is considered. A conclusion is made that the revisions suggested by Haroutiunian concern unessential parts of the content of work by Karakhanian et al. [Karakhanian, A., Djrbashian, R., Trifonov V., Philip H., Arakelian S., Avagian, A., 2002. Holocene-historical volcanism and active faults as natural risk factor for Armenia and adjacent countries. Journal of Volcanology and Geothermal Research, 113, 1, 319-344; Karakhanian, A., Jrbashyan, R., Trifonov, V., Philip, H., Arakelian, S., Avagyan, A., Baghdassaryan, H., Davtian, V., Ghoukassyan, Yu., 2003. Volcanic hazards in the region of the Armenian nuclear power plant. Journal of Volcanology and Geothermal Research, 126/1-2, 31-62]. This article presents new evidence and re-proves the earlier conclusions that are disputed or revised by R. Haroutiunian.

  4. A new version of regional ocean reanalysis for coastal waters of China and adjacent seas

    NASA Astrophysics Data System (ADS)

    Han, Guijun; Li, Wei; Zhang, Xuefeng; Wang, Xidong; Wu, Xinrong; Fu, Hongli; Zhang, Xiaoshuang; Zhang, Lianxin; Li, Dong

    2013-07-01

    A new regional ocean reanalysis over multiple decades (1958-2008) for the coastal waters of China and adjacent seas has been completed by the National Marine Data and Information Service (NMDIS) under the CORA (China Ocean ReAnalysis) project. Evaluations were performed on three aspects: (1) the improvement of general reanalysis quality; (2) eddy structures; and (3) decadal variability of sea surface height anomalies (SSHAs). Results showed that the quality of the new reanalysis has been enhanced beyond ˜40% (39% for temperature, 44% for salinity) in terms of the reduction of root mean squared errors (RMSEs) for which the reanalysis values were compared to observed values in the observational space. Compared to the trial version released to public in 2009, the new reanalysis is able to reproduce more detailed eddy structures as seen in satellite and in situ observations. EOF analysis of the reanalysis SSHAs showed that the new reanalysis reconstructs the leading modes of SSHAs much better than the old version. These evaluations suggest that the new CORA regional reanalysis represents a much more useful dataset for the community of the coastal waters of China and adjacent seas.

  5. Cryptic Population Structuring and the Role of the Isthmus of Tehuantepec as a Gene Flow Barrier in the Critically Endangered Central American River Turtle

    PubMed Central

    González-Porter, Gracia P.; Maldonado, Jesús E.; Flores-Villela, Oscar; Vogt, Richard C.; Janke, Axel; Fleischer, Robert C.; Hailer, Frank

    2013-01-01

    The critically endangered Central American River Turtle (Dermatemys mawii) is the only remaining member of the Dermatemydidae family, yet little is known about its population structuring. In a previous study of mitochondrial (mt) DNA in the species, three main lineages were described. One lineage (Central) was dominant across most of the range, while two other lineages were restricted to Papaloapan (PAP; isolated by the Isthmus of Tehuantepec and the Sierra de Santa Marta) or the south-eastern part of the range (1D). Here we provide data from seven polymorphic microsatellite loci and the R35 intron to re-evaluate these findings using DNA from the nuclear genome. Based on a slightly expanded data set of a total of 253 samples from the same localities, we find that mtDNA and nuclear DNA markers yield a highly congruent picture of the evolutionary history and population structuring of D. mawii. While resolution provided by the R35 intron (sequenced for a subset of the samples) was very limited, the microsatellite data revealed pronounced population structuring. Within the Grijalva-Usumacinta drainage basin, however, many populations separated by more than 300 kilometers showed signals of high gene flow. Across the entire range, neither mitochondrial nor nuclear DNA show a significant isolation-by-distance pattern, but both genomes highlight that the D. mawii population in the Papaloapan basin is genetically distinctive. Further, both marker systems detect unique genomic signals in four individuals with mtDNA clade 1D sampled on the southeast edge of the Grijalva-Usumacinta basin. These individuals may represent a separate cryptic taxon that is likely impacted by recent admixture. PMID:24086253

  6. Low Genetic Diversity and Strong Geographical Structure of the Critically Endangered White-Headed Langur (Trachypithecus leucocephalus) Inferred from Mitochondrial DNA Control Region Sequences

    PubMed Central

    Wang, Weiran; Qiao, Yu; Pan, Wenshi; Yao, Meng

    2015-01-01

    Many Asian colobine monkey species are suffering from habitat destruction and population size decline. There is a great need to understand their genetic diversity, population structure and demographic history for effective species conservation. The white-headed langur (Trachypithecus leucocephalus) is a Critically Endangered colobine species endemic to the limestone karst forests in southwestern China. We analyzed the mitochondrial DNA (mtDNA) control region sequences of 390 fecal samples from 40 social groups across the main distribution areas, which represented one-third of the total extant population. Only nine haplotypes and 10 polymorphic sites were identified, indicating remarkably low genetic diversity in the species. Using a subset of 77 samples from different individuals, we evaluated genetic variation, population structure, and population demographic history. We found very low values of haplotype diversity (h = 0.570 ± 0.056) and nucleotide diversity (π = 0.00323 ± 0.00044) in the hypervariable region I (HVRI) of the mtDNA control region. Distribution of haplotypes displayed marked geographical pattern, with one population (Chongzuo, CZ) showing a complete lack of genetic diversity (having only one haplotype), whereas the other population (Fusui, FS) having all nine haplotypes. We detected strong population genetic structure among habit patches (ΦST = 0.375, P < 0.001). In addition, the Mantel test showed a significant correlation between the pairwise genetic distances and geographical distances among social groups in FS (correlation coefficient = 0.267, P = 0.003), indicting isolation-by-distance pattern of genetic divergence in the mtDNA sequences. Analyses of demographic history suggested an overall stable historical population size and modest population expansion in the last 2,000 years. Our results indicate different genetic diversity and possibly distinct population history for different local populations, and suggest that CZ and FS should be

  7. Critical Thinking

    ERIC Educational Resources Information Center

    Villano, Matt

    2006-01-01

    True excellence in technology implementation emerges when IT, administrative, and academic leaders link IT to mission-critical institutional objectives, investing in hardware and software to serve an explicit purpose and a distinct population of users. This article illustrates that at public institutions of higher education in New Hampshire as…

  8. Ammonia- and methane-oxidizing microorganisms in high-altitude wetland sediments and adjacent agricultural soils.

    PubMed

    Yang, Yuyin; Shan, Jingwen; Zhang, Jingxu; Zhang, Xiaoling; Xie, Shuguang; Liu, Yong

    2014-12-01

    Ammonia oxidation is known to be carried out by ammonia-oxidizing bacteria (AOB) and archaea (AOA), while methanotrophs (methane-oxidizing bacteria (MOB)) play an important role in mitigating methane emissions from the environment. However, the difference of AOA, AOB, and MOB distribution in wetland sediment and adjacent upland soil remains unclear. The present study investigated the abundances and community structures of AOA, AOB, and MOB in sediments of a high-altitude freshwater wetland in Yunnan Province (China) and adjacent agricultural soils. Variations of AOA, AOB, and MOB community sizes and structures were found in water lily-vegetated and Acorus calamus-vegetated sediments and agricultural soils (unflooded rice soil, cabbage soil, and garlic soil and flooded rice soil). AOB community size was higher than AOA in agricultural soils and lily-vegetated sediment, but lower in A. calamus-vegetated sediment. MOB showed a much higher abundance than AOA and AOB. Flooded rice soil had the largest AOA, AOB, and MOB community sizes. Principal coordinate analyses and Jackknife Environment Clusters analyses suggested that unflooded and flooded rice soils had relatively similar AOA, AOB, and MOB structures. Cabbage soil and A. calamus-vegetated sediment had relatively similar AOA and AOB structures, but their MOB structures showed a large difference. Nitrososphaera-like microorganisms were the predominant AOA species in garlic soil but were present with a low abundance in unflooded rice soil and cabbage soil. Nitrosospira-like AOB were dominant in wetland sediments and agricultural soils. Type I MOB Methylocaldum and type II MOB Methylocystis were dominant in wetland sediments and agricultural soils. Moreover, Pearson's correlation analysis indicated that AOA Shannon diversity was positively correlated with the ratio of organic carbon to nitrogen (p < 0.05). This work could provide some new insights toward ammonia and methane oxidation in soil and wetland sediment

  9. Post larval, short-term, colonization patterns: The effect of substratum complexity across subtidal, adjacent, habitats

    NASA Astrophysics Data System (ADS)

    García-Sanz, Sara; Tuya, Fernando; Navarro, Pablo G.; Angulo-Preckler, Carlos; Haroun, Ricardo J.

    2012-10-01

    Benthic habitats are colonized by organisms from the water column and adjacent habitats. There are, however, variations in the 'acceptability' of any habitat to potential colonists. We assessed whether the structural complexity of artificial substrata affected patterns of short-term colonization of post larval faunal assemblages across subtidal habitats within a coastal landscape. Specifically, we tested whether short-term colonization patterns on 3 types of artificial substrata encompassing a range of complexities, including a leaf-like unit, a cushion-shaped leaf-like unit and a cushion-shaped unit, were consistent across 4 adjacent habitats: macroalgal-dominated bottoms, urchin-grazed barrens, seagrass meadows and sandy patches, at Gran Canaria (eastern Atlantic). A total of 16,174 organisms were collected after 4 weeks and 4 taxonomic groups (Crustacea, Chordata, Echinodermata and Mollusca) dominated the assemblage. Despite considerable among-taxa variability being observed in response to habitat effects, the total abundance of colonizers, as well as the abundance of Arthropoda, Chordata and Echinodermata, was affected by the habitat where collectors were deployed, but did not differ among types of collectors. Similarly, the assemblage structure of colonizers was mainly affected by the habitat, but not by the type of collector; habitat contributed to explain most variation in the assemblage structure of the four dominant taxonomic groups (from ca. 5.44-19.23%), and obscured, in all cases, variation explained by the type of collector. As a result, the variation in short-term colonization patterns of faunal assemblages into artificial collectors was mostly affected by variation associated with habitats rather than by differences in the structural complexity of collectors. The largest abundances of colonizers, particularly Echinodermata, were found on sandy patches relative to other habitats, suggesting that the 'availability', rather than any particular attribute

  10. Overcoming the Refractory Expression of Secreted Recombinant Proteins in Mammalian Cells through Modification of the Signal Peptide and Adjacent Amino Acids

    PubMed Central

    Güler-Gane, Gülin; Kidd, Sara; Sridharan, Sudharsan; Vaughan, Tristan J.; Wilkinson, Trevor C. I.

    2016-01-01

    The expression and subsequent purification of mammalian recombinant proteins is of critical importance to many areas of biological science. To maintain the appropriate tertiary structure and post-translational modifications of such proteins, transient mammalian expression systems are often adopted. The successful utilisation of these systems is, however, not always forthcoming and some recombinant proteins prove refractory to expression in mammalian hosts. In this study we focussed on the role of different N-terminal signal peptides and residues immediately downstream, in influencing the level of secreted recombinant protein obtained from suspension HEK293 cells. Using secreted alkaline phosphatase (SEAP) as a model protein, we identified that the +1/+2 downstream residues flanking a heterologous signal peptide significantly affect secreted levels. By incorporating these findings we conducted a comparison of different signal peptide sequences and identified the most productive as secrecon, a computationally-designed sequence. Importantly, in the context of the secrecon signal peptide and SEAP, we also demonstrated a clear preference for specific amino acid residues at the +1 position (e.g. alanine), and a detrimental effect of others (cysteine, proline, tyrosine and glutamine). When proteins that naturally contain these “undesirable” residues at the +1 position were expressed with their native signal peptide, the heterologous secrecon signal peptide, or secrecon with an additional alanine at the +1 or +1 and +2 position, the level of expression differed significantly and in an unpredictable manner. For each protein, however, at least one of the panel of signal peptide/adjacent amino acid combinations enabled successful recombinant expression. In this study, we highlight the important interplay between a signal peptide and its adjacent amino acids in enabling protein expression, and we describe a strategy that could enable recombinant proteins that have so far

  11. Overcoming the Refractory Expression of Secreted Recombinant Proteins in Mammalian Cells through Modification of the Signal Peptide and Adjacent Amino Acids.

    PubMed

    Güler-Gane, Gülin; Kidd, Sara; Sridharan, Sudharsan; Vaughan, Tristan J; Wilkinson, Trevor C I; Tigue, Natalie J

    2016-01-01

    The expression and subsequent purification of mammalian recombinant proteins is of critical importance to many areas of biological science. To maintain the appropriate tertiary structure and post-translational modifications of such proteins, transient mammalian expression systems are often adopted. The successful utilisation of these systems is, however, not always forthcoming and some recombinant proteins prove refractory to expression in mammalian hosts. In this study we focussed on the role of different N-terminal signal peptides and residues immediately downstream, in influencing the level of secreted recombinant protein obtained from suspension HEK293 cells. Using secreted alkaline phosphatase (SEAP) as a model protein, we identified that the +1/+2 downstream residues flanking a heterologous signal peptide significantly affect secreted levels. By incorporating these findings we conducted a comparison of different signal peptide sequences and identified the most productive as secrecon, a computationally-designed sequence. Importantly, in the context of the secrecon signal peptide and SEAP, we also demonstrated a clear preference for specific amino acid residues at the +1 position (e.g. alanine), and a detrimental effect of others (cysteine, proline, tyrosine and glutamine). When proteins that naturally contain these "undesirable" residues at the +1 position were expressed with their native signal peptide, the heterologous secrecon signal peptide, or secrecon with an additional alanine at the +1 or +1 and +2 position, the level of expression differed significantly and in an unpredictable manner. For each protein, however, at least one of the panel of signal peptide/adjacent amino acid combinations enabled successful recombinant expression. In this study, we highlight the important interplay between a signal peptide and its adjacent amino acids in enabling protein expression, and we describe a strategy that could enable recombinant proteins that have so far

  12. Simultaneous segmentation and generalisation of non-adjacent dependencies from continuous speech.

    PubMed

    Frost, Rebecca L A; Monaghan, Padraic

    2016-02-01

    Language learning requires mastering multiple tasks, including segmenting speech to identify words, and learning the syntactic role of these words within sentences. A key question in language acquisition research is the extent to which these tasks are sequential or successive, and consequently whether they may be driven by distinct or similar computations. We explored a classic artificial language learning paradigm, where the language structure is defined in terms of non-adjacent dependencies. We show that participants are able to use the same statistical information at the same time to segment continuous speech to both identify words and to generalise over the structure, when the generalisations were over novel speech that the participants had not previously experienced. We suggest that, in the absence of evidence to the contrary, the most economical explanation for the effects is that speech segmentation and grammatical generalisation are dependent on similar statistical processing mechanisms. PMID:26638049

  13. Air bubble-shock wave interaction adjacent to gelantine surface

    NASA Astrophysics Data System (ADS)

    Lush, P. A.; Tomita, Y.; Onodera, O.; Takayama, K.; Sanada, N.; Kuwahara, M.; Ioritani, N.; Kitayama, O.

    1990-07-01

    The interaction between a shock wave and an air bubble-adjacent to a gelatine surface is investigated in order to simulate human tissue damage resulting from extracorporeal shock wave lithotripsy. Using high speed cine photography it is found that a shock wave of strength 11 MPa causes 1-3 mm diameter bubbles to produce high velocity microjets with penetration rates of approximately 110 m/s and penetration depths approximately equal to twice the initial bubble diameter. Theoretical considerations for liquid impact on soft solid of similar density indicate that microjet velocities will be twice the penetration rate, i.e. 220 m/s in the present case. Such events are the probable cause of observed renal tissue damage.

  14. 38. METAL WORKING TOOLS AND MACHINES ADJACENT TO THE CIRCA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. METAL WORKING TOOLS AND MACHINES ADJACENT TO THE CIRCA 1900 MICHIGAN MACHINERY MFG. CO. PUNCH PRESS NEAR THE CENTER OF THE FACTORY BUILDING. AT THE LEFT FOREGROUND IS A MOVABLE TIRE BENDER FOR SHAPING ELI WINDMILL WHEEL RIMS. AT THE CENTER IS A FLOOR-MOUNTED CIRCA 1900 SNAG GRINDER OF THE TYPE USED FOR SMOOTHING ROUGH CASTINGS. ON THE WHEELED WORK STATION IS A SUNNEN BUSHING GRINDER, BEHIND WHICH IS A TRIPOD CHAIN VICE. IN THE CENTER BACKGROUND IS A WOODEN CHEST OF DRAWERS WHICH CONTAINS A 'RAG DRAWER' STILL FILLED WITH CLOTH RAGS PLACED IN THE FACTORY BUILDING AT THE INSISTENCE OF LOUISE (MRS. ARTHUR) KREGEL FOR THE CONVENIENCE AND CLEANLINESS OF WORKERS. IN THE LEFT BACKGROUND IS A CIRCA 1900 CROSS-CUTOFF CIRCULAR SAW. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  15. Laser ablation of human atherosclerotic plaque without adjacent tissue injury

    NASA Technical Reports Server (NTRS)

    Grundfest, W. S.; Litvack, F.; Forrester, J. S.; Goldenberg, T.; Swan, H. J. C.

    1985-01-01

    Seventy samples of human cadaver atherosclerotic aorta were irradiated in vitro using a 308 nm xenon chloride excimer laser. Energy per pulse, pulse duration and frequency were varied. For comparison, 60 segments were also irradiated with an argon ion and an Nd:YAG laser operated in the continuous mode. Tissue was fixed in formalin, sectioned and examined microscopically. The Nd:YAG and argon ion-irradiated tissue exhibited a central crater with irregular edges and concentric zones of thermal and blast injury. In contrast, the excimer laser-irradiated tissue had narrow deep incisions with minimal or no thermal injury. These preliminary experiments indicate that the excimer laser vaporizes tissue in a manner different from that of the continuous wave Nd:YAG or argon ion laser. The sharp incision margins and minimal damage to adjacent normal tissue suggest that the excimer laser is more desirable for general surgical and intravascular uses than are the conventionally used medical lasers.

  16. GOAT ROCKS WILDERNESS AND ADJACENT ROADLESS AREAS, WASHINGTON.

    USGS Publications Warehouse

    Church, S.E.; Close, T.J.

    1984-01-01

    The Goat Rocks Wilderness and adjacent roadless areas are a rugged, highly forested, scenic area located on the crest of the Cascade Range in south-central Washington. Several mineral claims have been staked in the area. Mineral surveys were conducted. Geochemical, geophysical, and geologic investigations indicate that three areas have probable mineral-resource potential for base metals in porphyry-type deposits. Available data are not adequate to permit definition of the potential for oil and gas. There is little likelihood for the occurrence of other kinds of energy resources in the area. Evaluation of resource potential in the three areas identified as having probable mineral-resource potential could be improved by more detailed geochemical studies and geologic mapping.

  17. Scolopendromorpha of New Guinea and adjacent islands (Myriapoda, Chilopoda).

    PubMed

    Schileyko, Arkady A; Stoev, Pavel E

    2016-01-01

    The centipede fauna of the second largest island in the world, New Guinea, and its adjacent islands, is poorly known, with most information deriving from the first half of the 20th century. Here we present new data on the order Scolopendromorpha based on material collected in the area in the last 40 years, mainly by Bulgarian and Latvian zoologists. The collections comprise eleven species of six genera and three families. The diagnosis of Cryptops (Trigonocryptops) is emended in the light of the recent findings. The old and doubtful record of Scolopendra multidens Newport, 1844 from New Guinea is referred to S. subspinipes Leach, 1815 and the species is here excluded from the present day list of New Guinean scolopendromorphs. Cryptops nepalensis Lewis, 1999 is here recorded from New Guinea for the first time. An annotated list and an identification key to the scolopendromorphs of the studied region are presented. PMID:27515618

  18. Increased apoptosis in gastric mucosa adjacent to intestinal metaplasia

    PubMed Central

    van Grieken, N C T; Meijer, G A; zur Hausen, A; Meuwissen, S G M; Baak, J P A; Kuipers, E J

    2003-01-01

    Background: The biological processes involved in the development of gastric mucosal atrophy and intestinal metaplasia are still incompletely understood. Reports testing the hypothesis that apoptosis leads to atrophy have yielded conflicting results. The availability of new antibodies for the detection of apoptotic cells in tissue sections has facilitated the analysis of the role of apoptosis in the gastritis–atrophy–intestinal metaplasia sequence. Methods: Archival material from 40 gastric resection specimens with normal mucosa (n = 5), chronic active gastritis (n = 17), or intestinal metaplasia (n = 18) was studied. Immunohistochemistry was performed using antibodies directed against cleaved cytokeratin 18 and active caspase 3. Slides were scored on a 0–3 scale for the presence of apoptotic cells. Results: Normal gastric mucosa contained low numbers of apoptotic cells at the surface epithelium (mean score, 0.20). This number was significantly increased in cases with chronic gastritis (mean score, 1.06) and in those with intestinal metaplasia (mean score, 2.56). Within the intestinal metaplasia cases, 44 different foci of intestinal metaplasia were identified. In 39 of these 44 areas, concentrations of apoptotic cells were seen immediately adjacent to the foci of intestinal metaplasia, but not in the metaplastic epithelium itself. Conclusions: Apoptosis is uncommon in normal gastric mucosa. Chronic inflammation and intestinal metaplasia are associated with increased apoptosis, but occur mainly at the mucosal surface and not in the deeper layers. These findings do not support the concept that apoptosis underlies the loss of gastric glands and leads to atrophy, but the observed concentration of apoptotic epithelial cells adjacent to foci of intestinal metaplasia could be related to heterogeneity of epithelial damage, causing apoptosis, to which intestinal metaplasia is a response. PMID:12719456

  19. Classical Hodgkin Lymphoma Arising Adjacent to a Breast Implant.

    PubMed

    Ryan, Ciara; Ged, Yasser; Quinn, Fiona; Walker, Jan; Kennedy, John; Gillham, Charles; Pittaluga, Stefania; McDermott, Ronan; Vandenberghe, Elisabeth; Grant, Cliona; Flavin, Richard

    2016-08-01

    Breast implant-associated lymphoma has recently gained wide recognition. Anaplastic large cell lymphoma (ALCL) is the most frequently diagnosed subtype in this setting but the spectrum is broadening. A 66-year-old woman developed swelling and itch around her saline implant 6 years after its insertion. Imaging revealed a fluid collection surrounding the implant with an adjacent mass. Microscopy showed sclerotic tissue punctuated by discrete cellular nodules comprising small lymphocytes, eosinophils and interspersed large atypical Hodgkin Reed-Sternberg (HRS)-like cells. The HRS-like cells stained positively for CD30 and CD15 by immunohistochemistry. Small T-lymphocytes formed rosettes around HRS-like cells. Appearances were consistent with classical Hodgkin lymphoma (HL). Multiplex polymerase chain reaction demonstrated no clonal rearrangements of immunoglobulin or T-cell receptor genes, however, a t(14;18)(q32;q21)BCL2-JH translocation involving the major breakpoint region of the bcl2 gene was present. Staging positron emission tomography-computed tomography scan revealed FDG-avid masses in the right axilla and pelvis. Subsequent pathological examination identified low-grade follicular lymphoma (FL) with a t(14;18) translocation at these sites. To our knowledge, this is the first case of HL arising adjacent to a breast implant. An awareness of this diagnosis is important as classical HL, with its prominent mixed inflammatory background, may be overlooked as a reactive process when histologically assessing capsulectomy specimens. It is also important in the differential diagnosis for implant-associated ALCL as both contain large atypical CD30-positive cells highlighting the need for full immunohistochemical and molecular workup in such cases. This case also adds to the large body of literature regarding the association between HL and FL. PMID:26888955

  20. Effect of Fluoridated Sealants on Adjacent Tooth Surfaces

    PubMed Central

    Cagetti, M.G.; Carta, G.; Cocco, F.; Sale, S.; Congiu, G.; Mura, A.; Strohmenger, L.; Lingström, P.; Campus, G.

    2014-01-01

    A double-blind randomized clinical trial was performed in 6- to 7-yr-old schoolchildren to evaluate, in a 30-mo period, whether the caries increment on the distal surface of the second primary molars adjacent to permanent first molars sealed with fluoride release compounds would be lower with respect to those adjacent to permanent first molars sealed with a nonfluoridated sealant. In sum, 2,776 subjects were enrolled and randomly divided into 3 groups receiving sealants on sound first molars: high-viscosity glass ionomer cement (GIC group); resin-based sealant with fluoride (fluoride-RB group); and a resin-based sealant without fluoride (RB group). Caries (D1 – D3 level) was recorded on the distal surface of the second primary molar, considered the unit of analysis including only sound surfaces at the baseline. At baseline, no differences in caries prevalence were recorded in the 3 groups regarding the considered surfaces. At follow-up, the prevalence of an affected unit of analysis was statistically lower (p = .03) in the GIC and fluoride-RB groups (p = .04). In the GIC group, fewer new caries were observed in the unit of analysis respect to the other 2 groups. Incidence rate ratios (IRRs) were 0.70 (95% confidence interval: 0.50, 0.68; p < .01) for GIC vs. RB and 0.79 (95% confidence interval: 0.53, 1.04; p = .005) for fluoride-RB vs. RB. Caries incidence was significantly associated with low socioeconomic status (IRR = 1.18; 95% confidence interval: 1.10, 1.42; p = .05). Dental sealant high-viscosity GIC and fluoride-RB demonstrated protection against dental caries, and there was evidence that these materials afforded additional protection for the tooth nearest to the sealed tooth (clinical trial registration NCT01588210). PMID:24846910

  1. Crystal Structure of Acivicin-Inhibited [gamma]-Glutamyltranspeptidase Reveals Critical Roles for Its C-Terminus in Autoprocessing and Catalysis

    SciTech Connect

    Williams, Kristin; Cullati, Sierra; Sand, Aaron; Biterova, Ekaterina I.; Barycki, Joseph J.

    2009-03-27

    Helicobacter pylori {gamma}-glutamyltranspeptidase (HpGT) is a general {gamma}-glutamyl hydrolase and a demonstrated virulence factor. The enzyme confers a growth advantage to the bacterium, providing essential amino acid precursors by initiating the degradation of extracellular glutathione and glutamine. HpGT is a member of the N-terminal nucleophile (Ntn) hydrolase superfamily and undergoes autoprocessing to generate the active form of the enzyme. Acivicin is a widely used {gamma}-glutamyltranspeptidase inhibitor that covalently modifies the enzyme, but its precise mechanism of action remains unclear. The time-dependent inactivation of HpGT exhibits a hyperbolic dependence on acivicin concentration with k{sub max} = 0.033 {+-} 0.006 s{sup -1} and K{sub I} = 19.7 {+-} 7.2 {micro}M. Structure determination of acivicin-modified HpGT (1.7 {angstrom}; R{sub factor} = 17.9%; R{sub free} = 20.8%) demonstrates that acivicin is accommodated within the {gamma}-glutamyl binding pocket of the enzyme. The hydroxyl group of Thr 380, the catalytic nucleophile in the autoprocessing and enzymatic reactions, displaces chloride from the acivicin ring to form the covalently linked complex. Within the acivicin-modified HpGT structure, the C-terminus of the protein becomes ordered with Phe 567 positioned over the active site. Substitution or deletion of Phe 567 leads to a >10-fold reduction in enzymatic activity, underscoring its importance in catalysis. The mobile C-terminus is positioned by several electrostatic interactions within the C-terminal region, most notably a salt bridge between Arg 475 and Glu 566. Mutational analysis reveals that Arg 475 is critical for the proper placement of the C-terminal region, the Tyr 433 containing loop, and the proposed oxyanion hole.

  2. Influence of defects on the critical behavior at the 105 K structural phase transition of SrTiO3: On the origin of the two length scale critical fluctuations

    NASA Astrophysics Data System (ADS)

    Hünnefeld, H.; Niemöller, T.; Schneider, J. R.; Rütt, U.; Rodewald, S.; Fleig, J.; Shirane, G.

    2002-07-01

    The temperature dependence of the sharp and the broad component of the critical scattering above the cubic-to-tetragonal phase transition of SrTiO3 has been studied by means of high-resolution triple-crystal diffractometry using 100-200 keV synchrotron radiation in five samples differing with respect to growth technique and oxygen vacancy concentrations. Emphasis is on changes in the critical behavior, the critical temperature, and the strain fields at the transition from bulk to surface. The sharp component was observed only in surface near regions of highly perfect crystals and is coupled to the occurrence of a long-range strain gradient that was identified by an exponential increase of mosaicity, lattice parameter fluctuations, and Bragg-peak intensity when approaching the surface from the bulk of the sample. Vanishing of the sharp component was observed at the polished/etched surface of a platelet cut off the large perfect crystal after release of strain due to free bending of the platelet. The values of the critical temperature observed in the bulk of the different samples vary between 98.7<=Tc<=105.8 K. In the surface near regions of a highly perfect float-zone grown crystal a variation of Tc of about 0.5 K has been found. Concerning the broad component the critical exponent describing the temperature dependence of the inverse correlation length κb varies between 0.73<=νb<=1.19, the exponent for the susceptibility between 1.49<=χb<=2.9, however, the ratio of the two exponents is almost sample independent and equal to χb/νb=2.1 with a variance of 0.2, in good agreement with the theoretical value of 1.97 obtained by LeGouillou and Zinn-Justin [Phys. Rev. B 21, 3976 (1980)]. The occurrence of the sharp component did not affect significantly the critical exponents for the underlying broad component of the critical scattering. The exponents for the sharp component observed in surface near layers of about 100 μ m thickness at the highly perfect float zone and

  3. Genetic diversity and population structure of the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) as revealed by mitochondrial and microsatellite DNA.

    PubMed

    Chen, Minmin; Zheng, Jinsong; Wu, Min; Ruan, Rui; Zhao, Qingzhong; Wang, Ding

    2014-01-01

    Ecological surveys have indicated that the population of the critically endangered Yangtze finless porpoise (YFP, Neophocaena asiaeorientalis asiaeorientalis) is becoming increasingly small and fragmented, and will be at high risk of extinction in the near future. Genetic conservation of this population will be an important component of the long-term conservation effort. We used a 597 base pair mitochondrial DNA (mtDNA) control region and 11 microsatellite loci to analyze the genetic diversity and population structure of the YFP. The analysis of both mtDNA and microsatellite loci suggested that the genetic diversity of the YFP will possibly decrease in the future if the population keeps declining at a rapid rate, even though these two types of markers revealed different levels of genetic diversity. In addition, mtDNA revealed strong genetic differentiation between one local population, Xingchang-Shishou (XCSS), and the other five downstream local populations; furthermore, microsatellite DNA unveiled fine but significant genetic differentiation between three of the local populations (not only XCSS but also Poyang Lake (PY) and Tongling (TL)) and the other local populations. With an increasing number of distribution gaps appearing in the Yangtze main steam, the genetic differentiation of local populations will likely intensify in the future. The YFP is becoming a genetically fragmented population. Therefore, we recommend attention should be paid to the genetic conservation of the YFP. PMID:24968271

  4. Genetic Diversity and Population Structure of the Critically Endangered Yangtze Finless Porpoise (Neophocaena asiaeorientalis asiaeorientalis) as Revealed by Mitochondrial and Microsatellite DNA

    PubMed Central

    Chen, Minmin; Zheng, Jinsong; Wu, Min; Ruan, Rui; Zhao, Qingzhong; Wang, Ding

    2014-01-01

    Ecological surveys have indicated that the population of the critically endangered Yangtze finless porpoise (YFP, Neophocaena asiaeorientalis asiaeorientalis) is becoming increasingly small and fragmented, and will be at high risk of extinction in the near future. Genetic conservation of this population will be an important component of the long-term conservation effort. We used a 597 base pair mitochondrial DNA (mtDNA) control region and 11 microsatellite loci to analyze the genetic diversity and population structure of the YFP. The analysis of both mtDNA and microsatellite loci suggested that the genetic diversity of the YFP will possibly decrease in the future if the population keeps declining at a rapid rate, even though these two types of markers revealed different levels of genetic diversity. In addition, mtDNA revealed strong genetic differentiation between one local population, Xingchang–Shishou (XCSS), and the other five downstream local populations; furthermore, microsatellite DNA unveiled fine but significant genetic differentiation between three of the local populations (not only XCSS but also Poyang Lake (PY) and Tongling (TL)) and the other local populations. With an increasing number of distribution gaps appearing in the Yangtze main steam, the genetic differentiation of local populations will likely intensify in the future. The YFP is becoming a genetically fragmented population. Therefore, we recommend attention should be paid to the genetic conservation of the YFP. PMID:24968271

  5. Using pre-critical PKiKP-PcP phases to constrain the regional structures of the inner core boundary beneath East Asia

    NASA Astrophysics Data System (ADS)

    Shen, Zhongyin; Ai, Yinshuang; He, Yumei; Jiang, Mingming

    2016-03-01

    We collected 177 pre-critical PKiKP-PcP records, assembling a wealth of traveltime and amplitude data. These observations sample the inner core boundary (ICB) beneath East Asia with good spatial coverage. Combined with previous studies, our results demonstrate a 100-km-wide anomaly with positive PKiKP-PcP traveltime residuals surrounded by negatives beneath the Yellow Sea area (123°E, 33°N) (Yellow Sea anomaly). After correcting the elliptic effects and mantle Vp heterogeneities based on the tomography models, the residuals of the Yellow Sea anomaly remain at least 0.6 s faster than those of the surrounding areas, suggesting a thickening of 2-3 km between the ICB and core mantle boundary (CMB). Due to the negative CMB topography along the western Pacific rim, we attribute this anomaly mainly to negative ICB topography. Across the northern border of the Yellow Sea anomaly, PKiKP/PcP amplitude ratios increase by approximately 50% from north to south, which can be explained by an approximately 0.6 g/cm3 raise in ICB density contrast. These traveltime and amplitude features suggest a mosaic structure at the ICB beneath the Yellow Sea areas.

  6. Topological analysis of the periodic structures in a harmonically driven bubble oscillator near Blake's critical threshold: Infinite sequence of two-sided Farey ordering trees

    NASA Astrophysics Data System (ADS)

    Hegedűs, Ferenc

    2016-03-01

    The topology of the stable periodic orbits of a harmonically driven bubble oscillator, the Rayleigh-Plesset equation, in the space of the excitation parameters (pressure amplitude and frequency) has been revealed numerically. This topology is governed by a hierarchy of two-sided Farey trees initiated from a unique primary structure defined also by a simple asymmetric Farey tree. The sub-topology of each of these building blocks is driven by a homoclinic tangency of a periodic saddle. This self-similar organisation is a suitable basis for a general description, since it is in good agreement with partial results obtained in other periodically forced oscillators and iterated maps. The applied ambient pressure in the model is near but still below Blake's critical threshold. Therefore, this paper is also a straightforward continuation of the work of Hegedűs [1], who first found numerical evidence for the existence of stable, period 1 solutions beyond Blake's threshold. The present findings are crucial for the extension of the available numerical results from period 1 to arbitrary periodicity.

  7. 33 CFR 110.140 - Buzzards Bay, Nantucket Sound, and adjacent waters, Mass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., and adjacent waters, Mass. 110.140 Section 110.140 Navigation and Navigable Waters COAST GUARD..., Nantucket Sound, and adjacent waters, Mass. Link to an amendment published at 76 FR 35744, June 20, 2011. (a... adjacent waters, Mass. (a) * * * (2) Anchorage B. All waters bounded by a line beginning at 41°36′42.3″...

  8. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... distilled spirits plant and adjacent bonded wine cellar. 19.162 Section 19.162 Alcohol, Tobacco Products and... bond for distilled spirits plant and adjacent bonded wine cellar. (a) One bond satisfying two requirements. A proprietor who operates a bonded wine cellar that is adjacent to the proprietor's...

  9. Pn tomographic velocity and anisotropy beneath the Tibetan Plateau and the adjacent regions

    NASA Astrophysics Data System (ADS)

    Lü, Y.; Ni, S.; Liu, B.; Sun, Y.

    2011-11-01

    We present a tomographic velocity and anisotropy model of the uppermost mantle beneath the Tibetan Plateau and the adjacent regions. The investigation analyzed 105,385 Pn phase readings from the International Seismological Centre (ISC) and the China Earthquake Data Center. The average Pn velocity under the study area is approximately 8.15 km/s, with velocity perturbations up to 3-4%. We find high Pn velocities under the Indian Plate and in the Tarim and Sichuan basins, low Pn velocities under the Hindu Kush and in Myanmar and the adjacent region, and especially low Pn velocities under the area north of the Indus-Yarlung Zangbo suture. The high Pn velocity anomalies of the Indian Plate are discontinuous at the collision region in the east-west direction, indicating that the Indian Plate probably subducts in a piecewise manner. Distributions of Pn velocities are used to validate mechanisms for the subduction of the Indian Plate presented in previous studies. In addition, Pn anisotropy is obtained simultaneously with Pn velocity. At plate collision zones, the fast Pn anisotropy direction is parallel to the direction of the collision edge. We validate the existence of Pn anisotropy under these regions and discuss the relationship of anisotropy with tectonic structure and plate movement.

  10. Diversity of fungi from the mound nests of Formica ulkei and adjacent non-nest soils.

    PubMed

    Duff, Lyndon B; Urichuk, Theresa M; Hodgins, Lisa N; Young, Jocelyn R; Untereiner, Wendy A

    2016-07-01

    Culture-based methods were employed to recover 3929 isolates of fungi from soils collected in May and July 2014 from mound nests of Formica ulkei and adjacent non-nest sites. The abundance, diversity, and richness of species from nest mounds exceeded those of non-mound soils, particularly in July. Communities of fungi from mounds were more similar to those from mounds than non-mounds; this was also the case for non-mound soils with the exception of one non-mound site in July. Species of Aspergillus, Paecilomyces, and Penicillium were dominant in nest soils and represented up to 81.8% of the taxa recovered. Members of the genus Aspergillus accounted for the majority of Trichocomaceae from nests and were represented almost exclusively by Aspergillus navahoensis and Aspergillus pseudodeflectus. Dominant fungi from non-mound sites included Cladosporium cladosporioides, Geomyces pannorum, and species of Acremonium, Fusarium, Penicillium, and Phoma. Although mound nests were warmer than adjacent soils, the dominance of xerotolerant Aspergillus in soils from mounds and the isolation of the majority of Trichocomaceae at 25 and 35 °C suggests that both temperature and water availability may be determinants of fungal community structure in nests of F. ulkei. PMID:27192606

  11. The ground beetles (Coleoptera: Carabidae) of the Strandzha Mountain and adjacent coastal territories (Bulgaria and Turkey)

    PubMed Central

    Guéorguiev, Borislav

    2016-01-01

    Abstract Background The knowledge of the ground-beetle fauna of Strandzha is currently incomplete, and is largely based on data from the Bulgarian part of the region and on records resulting from casual collecting. This study represents a critical revision of the available literature, museum collections and a three years field study of the carabid beetles of the Bulgarian and Turkish parts of Strandzha Mountain and the adjacent Black Sea Coast territories. New information A total of 328 species and subspecies of Carabidae, belonging to 327 species from the region of Strandzha Mountain and adjacent seacoast area, have been listed. Of these, 77 taxa represent new records for the Bulgarian part of the region, and 110 taxa new records for Turkish part of the studied region. Two taxa, one subgenus (Haptotapinus Reitter, 1886) and one species (Pterostichus crassiusculus), are new to the fauna of Bulgaria. Based on a misidentification, the species Apotomus testaceus is excluded from the list of the Bulgarian fauna. Seven species (Carabus violaceus azurescens, Apotomus rufus, Platynus proximus, Molops alpestris kalofericus, M. dilatatus angulicollis, Pterostichus merklii, and Calathus metallicus) are treated as doubtful for the regional fauna, and one (Apotomus rufus) also for the Bulgarian fauna. Altogether, 43 taxa collected in the Turkish part of the region are new for European Turkey. New taxa for Turkey are the genera Myas and Oxypselaphus, the subgenus Feronidius, and nine species and subspecies (Carabus granulatus granulatus, Dyschirius tristis, Bembidion normannum apfelbecki, B. subcostatum vau, Acupalpus exiguus, Myas chalybaeus, Oxypselaphus obscurus, Pterostichus leonisi, Pt. melas). In addition, there are a further seven species that are here confirmed for Turkey. PMID:27099564

  12. New Classification for Clinically Symptomatic Adjacent Segment Pathology in Cervical Disc Disease

    PubMed Central

    2015-01-01

    Study Design Clinical adjacent segment pathology (CASP) is common after cervical disc surgery. A critical examination of 320 patients operated for cervical disc prolapse revealed that CASP can also occur in patients with congenital and degenerative fusion of cervical spine. This has not been studied in depth and there is a need for a practically applicable classification of CASP. Purpose To develop a new classification scheme of CASP. Overview of Literature A review of the literature did not reveal a practically applicable classification incorporating the occurrence of CASP in congenital and degenerative fusion cases. Methods This was a retrospective analysis of 320 patients operated (509 disc spaces) on for cervical disc prolapse. Cases (n=316) were followed-up for 3-11 years. Random sampling of 220 patients with postoperative magnetic resonance imaging (MRI) in 165 cases was analyzed. Results Six symptomatic CASP cases required resurgery (1.9%), eight cases involved MRI proven CASP with axial neck pain only and 13 patients were asymptomatic with radiological adjacent segment pathology (RASP). The frequency rate was 8.5% (27/316). Four cases of congenital or degenerative fusion of vertebra developed CASP requiring surgery. CASP is classified as primary or secondary follows. Primary A1 was congenital fusion of vertebra and primary A2 was degenerative fusion of the vertebra. Secondary, which was after cervical disc surgery, comprised B1 (RASP in asymptomatic patients), B2 (CASP in patients with axial neck pain), and B3 (CASP with myeloradiculopathy). B3 was subdivided into single-level CASP (B3a) and multiple-level CASP (B3b). Conclusions Symptomatic CASP requiring resurgery is infrequent. CASP can occur in patients with congenital and degenerative fusion of the cervical spine. A new classification for CASP along with treatment strategy is proposed. Patients in Primary CASP and B3 CASP require resurgery while others require only observation. PMID:26712514

  13. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2001 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The thermostat for CVX sits inside the white cylinder on a support structure that is placed inside a pressure canister. A similar canister holds the electronics and control systems. The CVX-2 arrangement is identical. The principal investigator is Dr. Robert F. Berg (not shown) of the National Institutes of Standards and Technology, Gaithersburg, MD. This is a detail view of MSFC 0100143.

  14. Capping motifs stabilize the leucine-rich repeat protein PP32 and rigidify adjacent repeats.

    PubMed

    Dao, Thuy P; Majumdar, Ananya; Barrick, Doug

    2014-06-01

    Capping motifs are found to flank most β-strand-containing repeat proteins. To better understand the roles of these capping motifs in organizing structure and stability, we carried out folding and solution NMR studies on the leucine-rich repeat (LRR) domain of PP32, which is composed of five tandem LRR, capped by α-helical and β-hairpin motifs on the N- and C-termini. We were able to purify PP32 constructs lacking either cap and containing destabilizing substitutions. Removing the C-cap results in complete unfolding of PP32. Removing the N-cap has a much less severe effect, decreasing stability but retaining much of its secondary structure. In contrast, the dynamics and tertiary structure of the first two repeats are significantly perturbed, based on (1)H-(15)N relaxation studies, chemical shift perturbations, and residual dipolar couplings. However, more distal repeats (3 to C-cap) retain their native tertiary structure. In this regard, the N-cap drives the folding of adjacent repeats from what appears to be a molten-globule-like state. This interpretation is supported by extensive analysis using core packing substitutions in the full-length and N-cap-truncated PP32. This work highlights the importance of caps to the stability and structural integrity of β-strand-containing LRR proteins, and emphasizes the different contributions of the N- and C-terminal caps. PMID:24659532

  15. Challenging the state-of-the-art in protein structure prediction: Highlights of experimental target structures for the 10th Critical Assessment of Techniques for Protein Structure Prediction Experiment CASP10

    PubMed Central

    Kryshtafovych, Andriy; Moult, John; Bales, Patrick; Bazan, J. Fernando; Biasini, Marco; Burgin, Alex; Chen, Chen; Cochran, Frank V.; Craig, Timothy K.; Das, Rhiju; Fass, Deborah; Garcia-Doval, Carmela; Herzberg, Osnat; Lorimer, Donald; Luecke, Hartmut; Ma, Xiaolei; Nelson, Daniel C.; van Raaij, Mark J.; Rohwer, Forest; Segall, Anca; Seguritan, Victor; Zeth, Kornelius; Schwede, Torsten

    2014-01-01

    For the last two decades, CASP has assessed the state of the art in techniques for protein structure prediction and identified areas which required further development. CASP would not have been possible without the prediction targets provided by the experimental structural biology community. In the latest experiment, CASP10, over 100 structures were suggested as prediction targets, some of which appeared to be extraordinarily difficult for modeling. In this paper, authors of some of the most challenging targets discuss which specific scientific question motivated the experimental structure determination of the target protein, which structural features were especially interesting from a structural or functional perspective, and to what extent these features were correctly reproduced in the predictions submitted to CASP10. Specifically, the following targets will be presented: the acid-gated urea channel, a difficult to predict trans-membrane protein from the important human pathogen Helicobacter pylori; the structure of human interleukin IL-34, a recently discovered helical cytokine; the structure of a functionally uncharacterized enzyme OrfY from Thermoproteus tenax formed by a gene duplication and a novel fold; an ORFan domain of mimivirus sulfhydryl oxidase R596; the fibre protein gp17 from bacteriophage T7; the Bacteriophage CBA-120 tailspike protein; a virus coat protein from metagenomic samples of the marine environment; and finally an unprecedented class of structure prediction targets based on engineered disulfide-rich small proteins. PMID:24318984

  16. The Current Tectonics of the Yukon and Adjacent Area

    NASA Astrophysics Data System (ADS)

    Hyndman, R. D.; Leonard, L. J.

    2014-12-01

    The current tectonics across the Yukon and adjacent areas of western Northwest Territories (NWT) and northern British Columbia appear to be driven primarily by the Yakutat Terrane collision, an "indenter" in the corner of the Gulf of Alaska. GPS data show 1-10 mm/yr northward and eastward, decreasing inland. The rates from earthquake statistics are similar although there are important discrepancies. The eastern Cordillera earthquake mechanisms are mainly thrust in the Mackenzie Mountains of southwestern NWT where the Cordillera upper crust is overthrusting the craton. To the north, the mechanisms are mainly strike-slip in the Richardson Mountains that appear to lie along the edge of the craton. The deformation appears to be limited to the hot and weak Cordillera with the strong craton providing an irregular eastern boundary. For example, there is an eastward bow in the craton edge and the deformation in the Mackenzie Mountains. On the Beaufort Sea margin in the region of the Mackenzie Delta there appears to be a type of "subduction zone" with the continent very slowly overthrusting the oceanic plate, a process that has continued since at least the Cretaceous. A northward moving continental margin block is bounded by left lateral faulting in the west (Canning Displacement Zone of eastern Alaska) and right lateral faulting in the east (Richardson Mountains in eastern Yukon). There is almost no seismicity on this thrust belt but as for some other subduction zones such as Cascadia there is the potential for very infrequent great earthquakes.

  17. [Comparative proteomic analysis of cancerous and adjacent normal lung tissues].

    PubMed

    Lee, Ki Beom; Pi, Kyung Bae

    2010-01-01

    Lung cancer is the leading cause of cancer-related mortality in industrialized countries. Unfortunately, most lung cancers are found too late for a cure, therefore early detection and treatment is very important. We have applied proteomic analysis by using two-dimensional gel electrophoresis and peptide mass fingerprinting techniques for examination of cancerous and adjacent non-cancerous lung tissues from the same patient. The aim of the study was to find proteins, which could be used as biomarkers for diagnosis and monitoring of this disease. Indeed, we found differences in expression of several proteins, related to various cellular activities, such as, chaperoning (e.g., GRP96, GRP78, HSP27), metabolism and oxidation stress (e.g., L-fucose, GST), cytoskeleton (e.g., tubulin beta 2/3, beta actin), cell adhesion (e.g., annexin A5/3), binding proteins (e.g., 14-3-3 theta) and signal transduction. These changes may be important for progression of carcinogenesis; they may be used as the molecular-support for future diagnostic markers. PMID:21395069

  18. Snow Distribution Patterns in Clearings and Adjacent Forest

    NASA Astrophysics Data System (ADS)

    Golding, Douglas L.; Swanson, Robert H.

    1986-12-01

    Snow accumulation patterns were determined for clearings and adjacent forest at Marmot Creek experimental watershed and James River, Alberta. At maximum accumulation snow water equivalent (SWE) was greater in clearings than in forest whether clearings were large, as in 8- to 13-ha blocks where SWE averaged 20% more than in the forest, or small as in the ¼ to 6-H (height) diameter circular clearings where SWE was 13-45% greater than in the forest. SWE was 42 to 52% less in north than in south sectors of 2-6 H clearings. These differences increased with clearing size and time since beginning of accumulation period and are caused by snow ablation (melt and evaporation), a function of direct solar radiation reaching the snowpack. In such situations the snow that has accumulated on the ground cannot be considered a measure of the snow that has actually fallen there. For water balances and hydrologic modeling, snow measurements in partially cleared watersheds must be adjusted for temporal and spatial factors specific to the watershed.

  19. Particulate Matter Levels in Ambient Air Adjacent to Industrial Area

    NASA Astrophysics Data System (ADS)

    Mohamed, R. M. S. R.; Nizam, N. M. S.; Al-Gheethi, A. A.; Lajis, A.; Kassim, A. H. M.

    2016-07-01

    Air quality in the residential areas adjacent to the industrial regions is of great concern due to the association with human health risks. In this work, the concentrations of particulate matter (PM10) in the ambient air of UTHM campus was investigated tostudy the air qualityand their compliance to the Malaysian Ambient Air Quality Guidelines (AAQG). The PM10 samples were taken over 24 hours from the most significant area at UTHM including Stadium, KolejKediamanTunDr. Ismail (KKTDI) and MakmalBahan. The meteorological parameters; temperature, relative humidity, wind speed and wind direction as well as particulate matterwere estimated by using E-Sampler Particulate Matter (PM10) Collector. The highest concentrations of PM10 (55.56 µg/m3) was recorded at MakmalBahan during the working and weekend days. However, these concentrations are less than 150 pg/m3. It can be concluded that although UTHM is surrounded by the industrial area, the air quality in the campus still within the standards limits.

  20. Macrobenthos of Yenisei Bay and the adjacent Kara Sea shelf

    NASA Astrophysics Data System (ADS)

    Galkin, S. V.; Vedenin, A. A.

    2015-07-01

    Trawl samples were collected in the northern region of Yenisei Bay and adjacent parts of the Kara Sea shelf. A total of eight stations were taken. We found more than 200 species of benthic organisms. A consecutive replacement of benthic communities is observed when going to the north from the Ob and Yenisei estuaries to the open parts of the sea. We could distinguish four different species complexes in the investigated area: a brackish-water complex where Saduria entomon is dominant; an intermediate complex where S. sibirica, S. sabini and Portlandia aestuariorum are dominant; a transitional complex with P. arctica as a dominant species and with a small amount of Ophiocten sericeum; a marine complex where O. sericeum is dominant. When salinity increased, some brackish-water species were replaced by related euryhaline species. One such example was the replacement of brackish-water Saduria entomon isopods by two euryhaline species: S. sibirica and S. sabini. The consecutive replacement of benthic communities showed a break near Sverdrup Island. In this area the marine complex was replaced by a transitional complex with P. arctica.

  1. Herbicide interchange between a stream and the adjacent alluvial aquifer

    USGS Publications Warehouse

    Wang, W.; Squillace, P.

    1994-01-01

    Herbicide interchange between a stream and the adjacent alluvial aquifer and quantification of herbicide bank storage during high streamflow were investigated at a research site on the Cedar River flood plain, 10 km southeast of Cedar Rapids, Iowa. During high streamflow in March 1990, alachlor, atrazine, and metolachlor were detected at concentrations above background in water from wells as distant as 20, 50, and 10 m from the river's edge, respectively. During high streamflow in May 1990, alachlor, atrazine, cyanazine, and metolachlor were detected at concentrations above background as distant as 20, 50, 10, and 20 m from the river's edge, respectively. Herbicide bank storage took place during high streamflow when hydraulic gradients were from the river to the alluvial aquifer and the laterally infiltrating river water contained herbicide concentrations larger than background concentrations in the aquifer. The herbicide bank storage can be quantified by multiplying herbicide concentration by the "effective area" that a well represented and an assumed porosity of 0.25. During March 1990, herbicide bank storage values were calculated to be 1.7,79, and 4.0 mg/m for alachlor, atrazine, and metolachlor, respectively. During May 1990, values were 7.1, 54, 11, and 19 mg/m for alachlor, atrazine, cyanazine, and metolachlor, respectively. ?? 1994 American Chemical Society.

  2. Apical infection spreading to adjacent teeth: a case report.

    PubMed

    Komabayashi, Takashi; Jiang, Jin; Zhu, Qiang

    2011-06-01

    This case report describes apical infection on tooth number 24 that spread to adjacent teeth, resulting in devitalized teeth numbers 23 and 25. The 25-year-old Caucasian female patient was referred to the endodontic resident clinic because of uncontrolled apical infection. Root-end surgery and root-end filling of teeth numbers 23, 24, and 25 were performed. The histopathological diagnosis was a periapical cyst; however, the clinical surgical finding of a purulence-filled bone cavity also revealed a periapical abscess. After root-end surgery and regenerative therapy using Mineral Trioxide Aggregate, Bio-Oss xenograft material, and Bio-Gide resorbable collagen membrane, the patient had no symptoms. Radiographs showed the apical lesion had healed satisfactorily at the 6-month, 1-year, and 2-year follow-ups. The clinical implication of this rare case suggests the importance of standard endodontic diagnostic procedures for pulpal and apical diagnosis, prevention of apical periodontitis exacerbation by reducing bacterial factors, and the effectiveness of healing large bone defects using regenerative materials. PMID:21458327

  3. Seismic responses of two adjacent buildings. I. Data and analyses

    USGS Publications Warehouse

    Celebi, Mehmet

    1993-01-01

    In this two-part paper, responses of two, adjacent, seven-story buildings in Norwalk, California, to the Whittier-Narrows, Calif, earthquake of Oct. 1, 1987 are studied. Building A, instrumented according to code recommendations, and building B, extensively instrumented, are offset by 16.3 m from one another. The data set includes motions from the superstructure of both buildings, from a downhole below the foundation of building B, and from three free-field sites. Part I of the paper includes descriptions of the buildings, site, instrumentation, and analysis of the data of each building. System identification and spectral analysis techniques are employed in part I. Building A has identical first-mode frequencies of 0.65 Hz for both building axes. The strong-motion response characteristics of building A are considerably different than those determined from low-amplitude tests. Building B has fundamental modes at 0.76 Hz and 0.83 Hz in the major and minor axes, respectively. Torsional and diaphragm effects in building B are negligible.

  4. Concentric network symmetry grasps authors' styles in word adjacency networks

    NASA Astrophysics Data System (ADS)

    Amancio, Diego R.; Silva, Filipi N.; Costa, Luciano da F.

    2015-06-01

    Several characteristics of written texts have been inferred from statistical analysis derived from networked models. Even though many network measurements have been adapted to study textual properties at several levels of complexity, some textual aspects have been disregarded. In this paper, we study the symmetry of word adjacency networks, a well-known representation of text as a graph. A statistical analysis of the symmetry distribution performed in several novels showed that most of the words do not display symmetric patterns of connectivity. More specifically, the merged symmetry displayed a distribution similar to the ubiquitous power-law distribution. Our experiments also revealed that the studied metrics do not correlate with other traditional network measurements, such as the degree or the betweenness centrality. The discriminability power of the symmetry measurements was verified in the authorship attribution task. Interestingly, we found that specific authors prefer particular types of symmetric motifs. As a consequence, the authorship of books could be accurately identified in 82.5% of the cases, in a dataset comprising books written by 8 authors. Because the proposed measurements for text analysis are complementary to the traditional approach, they can be used to improve the characterization of text networks, which might be useful for applications based on stylistic classification.

  5. Seismic responses of two adjacent buildings. II. Interaction

    USGS Publications Warehouse

    Celebi, Mehmet

    1993-01-01

    Presented in this part of the two-part paper is a study of the relations between earthquake motions recorded from two, adjacent, seven-story buildings, from a downhole below the foundation of one of the buildings and from three free-field sites, all within one city block. This unique data set was obtained during the Whittier-Narrows, Calif. earthquake of Oct. 1, 1987, Part I includes background information on the two buildings, the site, and the data set. Building response characteristics of a code-type instrumented building (A) and an extensively instrumented building (B) are also studied. In this part, spectral analysis techniques are used to study the relationships between the motions of the roofs and basements, the downhole and the free-field sites. It is asserted that there is building-soil-building interaction between the two buildings at a frequency of 2.35 Hz. Furthermore, the free-field motions are shown to be influenced by the presence of the buildings.

  6. Parasites of two native fishes in adjacent Adirondack lakes.

    PubMed

    Bauer, Eric F; Whipps, Christopher M

    2013-08-01

    This survey of parasites in 2 adjacent lakes is the first of its kind in the Adirondack Park of New York State. Wolf Lake is designated as a heritage lake whereas nearby Deer Lake is limnologically similar but has at least 5 introduced fish species. Both lakes have 2 native species, i.e., white sucker (Catostomus commersoni) and redbreast sunfish (Lepomis auritus), which were the focus of this study. Parasite communities of both hosts were surveyed and compared between each lake and were statistically evaluated for differences in species similarity, prevalence, mean intensity, and mean abundance. Between lakes, white suckers had significant differences in the prevalence of 4 parasite species (Myxobolus sp. 2, Myxobolus bibulatus, Octospinifer macilentis, and Pomphorhynchus bulbocoli) and mean abundances of 4 parasites (neascus larvae, Octospinifer macilentis, Pomphorhynchus bulbocoli, and Glaridacris confusus). Redbreast sunfish had significant differences in the prevalence of 3 species (Myxobolus uvuliferis, a coccidian species, and Spinitectus carolini) and differences in parasite mean abundance of 5 species (neascus larvae, Clinostomum marginatum , Leptorhynchoides thecatus, Spinitectus carolini, and Eustrongylides sp.). Differences in component communities between lakes were found and, although the exact causes cannot be determined by this study, we speculate on several possible explanations. PMID:23384764

  7. Critical mechanical structure of superconducting high current coils for fast ramped accelerator magnets with high repetition rates in long term operation

    NASA Astrophysics Data System (ADS)

    Fischer, E.; Schnizer, P.; Weiss, K.; Nyilas, A.; Mierau, A.; Sikler, G.

    2010-06-01

    The heavy ion synchrotron SIS100 is the core component of the Facility for Antiproton and Ion Research (FAIR) currently under construction at GSI in Darmstadt. It is rapidly cycled with a ramp rate of 4 T/s up to 2 T maximum field and a repetition frequency of 1 Hz. The superconducting coils of the Nuclotron-type magnets utilise a hollow cable cooled with a forced two phase helium flow. These coils must operate reliably over a period of at least 20 years and thus survive 2 · 10 load cycles. Intensive R&D is necessary to find the optimal solution preventing any possible damage of the coils by the fast pulsing loads over the life time taking into account the complex fine structure of the cable and coil designs as well as its sensitive influence on the field quality, AC loss generation and quench protection. We used FEM codes to analyse critical aspects of various design options and had manufactured coils for detailed mechanical tests. These tests on samples extracted from the coil are: thermal expansion measurements in all three directions on the cable package itself and its composite elements, compression tests and investigation of the Inter Laminar Shear Stress (ILSS). The stress strain behaviour of the cable package was measured along the transversal direction; the most important one to sustain the cycling load by Lorentz forces. A second sample was fatigue tested. Successful integral operation test results for the coil mechanics have been obtained within our first experimental runs on the prototype dipole magnets already started at GSI in the end of 2008.

  8. Exploring the Anti-Cancer Activity of Novel Thiosemicarbazones Generated through the Combination of Retro-Fragments: Dissection of Critical Structure-Activity Relationships

    PubMed Central

    Rasko, Nathalie; Potůčková, Eliška; Mrozek-Wilczkiewicz, Anna; Musiol, Robert; Małecki, Jan G.; Sajewicz, Mieczysław; Ratuszna, Alicja; Muchowicz, Angelika; Gołąb, Jakub; Šimůnek, Tomáš; Richardson, Des R.; Polanski, Jaroslaw

    2014-01-01

    Thiosemicarbazones (TSCs) are an interesting class of ligands that show a diverse range of biological activity, including anti-fungal, anti-viral and anti-cancer effects. Our previous studies have demonstrated the potent in vivo anti-tumor activity of novel TSCs and their ability to overcome resistance to clinically used chemotherapeutics. In the current study, 35 novel TSCs of 6 different classes were designed using a combination of retro-fragments that appear in other TSCs. Additionally, di-substitution at the terminal N4 atom, which was previously identified to be critical for potent anti-cancer activity, was preserved through the incorporation of an N4-based piperazine or morpholine ring. The anti-proliferative activity of the novel TSCs were examined in a variety of cancer and normal cell-types. In particular, compounds 1d and 3c demonstrated the greatest promise as anti-cancer agents with potent and selective anti-proliferative activity. Structure-activity relationship studies revealed that the chelators that utilized “soft” donor atoms, such as nitrogen and sulfur, resulted in potent anti-cancer activity. Indeed, the N,N,S donor atom set was crucial for the formation of redox active iron complexes that were able to mediate the oxidation of ascorbate. This further highlights the important role of reactive oxygen species generation in mediating potent anti-cancer activity. Significantly, this study identified the potent and selective anti-cancer activity of 1d and 3c that warrants further examination. PMID:25329549

  9. Exploring the anti-cancer activity of novel thiosemicarbazones generated through the combination of retro-fragments: dissection of critical structure-activity relationships.

    PubMed

    Serda, Maciej; Kalinowski, Danuta S; Rasko, Nathalie; Potůčková, Eliška; Mrozek-Wilczkiewicz, Anna; Musiol, Robert; Małecki, Jan G; Sajewicz, Mieczysław; Ratuszna, Alicja; Muchowicz, Angelika; Gołąb, Jakub; Simůnek, Tomáš; Richardson, Des R; Polanski, Jaroslaw

    2014-01-01

    Thiosemicarbazones (TSCs) are an interesting class of ligands that show a diverse range of biological activity, including anti-fungal, anti-viral and anti-cancer effects. Our previous studies have demonstrated the potent in vivo anti-tumor activity of novel TSCs and their ability to overcome resistance to clinically used chemotherapeutics. In the current study, 35 novel TSCs of 6 different classes were designed using a combination of retro-fragments that appear in other TSCs. Additionally, di-substitution at the terminal N4 atom, which was previously identified to be critical for potent anti-cancer activity, was preserved through the incorporation of an N4-based piperazine or morpholine ring. The anti-proliferative activity of the novel TSCs were examined in a variety of cancer and normal cell-types. In particular, compounds 1d and 3c demonstrated the greatest promise as anti-cancer agents with potent and selective anti-proliferative activity. Structure-activity relationship studies revealed that the chelators that utilized "soft" donor atoms, such as nitrogen and sulfur, resulted in potent anti-cancer activity. Indeed, the N,N,S donor atom set was crucial for the formation of redox active iron complexes that were able to mediate the oxidation of ascorbate. This further highlights the important role of reactive oxygen species generation in mediating potent anti-cancer activity. Significantly, this study identified the potent and selective anti-cancer activity of 1d and 3c that warrants further examination. PMID:25329549

  10. Rpn1 provides adjacent receptor sites for substrate binding and deubiquitination by the proteasome

    PubMed Central

    Shi, Yuan; Chen, Xiang; Elsasser, Suzanne; Stocks, Bradley B.; Tian, Geng; Lee, Byung-Hoon; Shi, Yanhong; Zhang, Naixia; de Poot, Stefanie A. H.; Tuebing, Fabian; Sun, Shuangwu; Vannoy, Jacob; Tarasov, Sergey G.; Engen, John R.; Finley, Daniel; Walters, Kylie J.

    2016-01-01

    Structured Abstract INTRODUCTION The ubiquitin-proteasome system comprises hundreds of distinct pathways of degradation, which converge at the step of ubiquitin recognition by the proteasome. Five proteasomal ubiquitin receptors have been identified, two that are intrinsic to the proteasome (Rpn10 and Rpn13) and three reversibly associated proteasomal ubiquitin receptors (Rad23, Dsk2, and Ddi1). RATIONALE We found that the five known proteasomal ubiquitin receptors of yeast are collectively nonessential for ubiquitin recognition by the proteasome. We therefore screened for additional ubiquitin receptors in the proteasome and identified subunit Rpn1 as a candidate. We used nuclear magnetic resonance (NMR) spectroscopy to characterize the structure of the binding site within Rpn1, which we term the T1 site. Mutational analysis of this site showed its functional importance within the context of intact proteasomes. T1 binds both ubiquitin and ubiquitin-like (UBL) proteins, in particular the substrate-delivering shuttle factor Rad23. A second site within the Rpn1 toroid, T2, recognizes the UBL domain of deubiquitinating enzyme Ubp6, as determined by hydrogen-deuterium exchange mass spectrometry analysis and validated by amino acid substitution and functional assays. The Rpn1 toroid thus serves a critical scaffolding role within the proteasome, helping to assemble multiple proteasome cofactors as well as substrates. RESULTS Our results indicate that proteasome subunit Rpn1 can recognize both ubiquitin and UBL domains of substrate shuttling factors that themselves bind ubiquitin and function as reversibly-associated proteasomal ubiquitin receptors. Recognition is mediated by the T1 site within the Rpn1 toroid, which supports proteasome function in vivo. We found that the capacity of T1 to recognize both ubiquitin and UBL proteins was shared with Rpn10 and Rpn13. The surprising multiplicity of ubiquitin-recognition domains within the proteasome may promote enhanced

  11. Highly condensed chromatins are formed adjacent to subtelomeric and decondensed silent chromatin in fission yeast

    PubMed Central

    Matsuda, Atsushi; Chikashige, Yuji; Ding, Da-Qiao; Ohtsuki, Chizuru; Mori, Chie; Asakawa, Haruhiko; Kimura, Hiroshi; Haraguchi, Tokuko; Hiraoka, Yasushi

    2015-01-01

    It is generally believed that silent chromatin is condensed and transcriptionally active chromatin is decondensed. However, little is known about the relationship between the condensation levels and gene expression. Here we report the condensation levels of interphase chromatin in the fission yeast Schizosaccharomyces pombe examined by super-resolution fluorescence microscopy. Unexpectedly, silent chromatin is less condensed than the euchromatin. Furthermore, the telomeric silent regions are flanked by highly condensed chromatin bodies, or ‘knobs'. Knob regions span ∼50 kb of sequence devoid of methylated histones. Knob condensation is independent of HP1 homologue Swi6 and other gene silencing factors. Disruption of methylation at lysine 36 of histone H3 (H3K36) eliminates knob formation and gene repression at the subtelomeric and adjacent knob regions. Thus, epigenetic marks at H3K36 play crucial roles in the formation of a unique chromatin structure and in gene regulation at those regions in S. pombe. PMID:26205977

  12. Navigated Pin-Point Approach to Osteoid Osteoma Adjacent to the Facet Joint of Spine

    PubMed Central

    Neo, Masashi; Takemoto, Mitsuru; Nishizawa, Kazuya; Imai, Shinji

    2016-01-01

    Osteoid osteoma (OO) is a benign osteoblastic tumor. Its curative treatment is complete removal of the nidus, where intraoperative localization of the nidus governs clinical results. However, treatment can be difficult since the lesion is often invisible over the bony surface. Accordingly, establishment of an ideal less invasive surgical strategy for spinal OO remains yet unsettled. We illustrate the efficacy of a computed tomography (CT)-based navigation system in excising OO located adjacent to the facet joint of spine. In our 2 cases, complete and pin-point removal of the nidus located close to the facet joint was successfully achieved, without excessive removal of the bone potentially leading to spinal instability and possible damage of nearby neurovascular structures. We advocate a less invasive approach to spinal OO, particularly in an environment with an available CT-based navigation system. PMID:26949472

  13. Contrasting microbial assemblages in adjacent water masses associated with the East Australian Current.

    PubMed

    Seymour, Justin R; Doblin, Martina A; Jeffries, Thomas C; Brown, Mark V; Newton, Kelly; Ralph, Peter J; Baird, Mark; Mitchell, James G

    2012-10-01

    Different oceanographic provinces host discrete microbial assemblages that are adapted to local physicochemical conditions. We sequenced and compared the metagenomes of two microbial communities inhabiting adjacent water masses in the Tasman Sea, where the recent strengthening of the East Australian Current (EAC) has altered the ecology of coastal environments. Despite the comparable latitude of the samples, significant phylogenetic differences were apparent, including shifts in the relative frequency of matches to Cyanobacteria, Crenarchaeota and Euryarchaeota. Fine-scale variability in the structure of SAR11, Prochlorococcus and Synechococcus populations, with more matches to 'warm-water' ecotypes observed in the EAC, indicates the EAC may drive an intrusion of tropical microbes into temperate regions of the Tasman Sea. Furthermore, significant shifts in the relative importance of 17 metabolic categories indicate that the EAC prokaryotic community has different physiological properties than surrounding waters. PMID:23760900

  14. Spatiotemporal distribution of bacterioplankton and bacteriobenthos in the Amur Liman and adjacent sea areas

    NASA Astrophysics Data System (ADS)

    Karetnikova, E. A.; Garetova, L. A.

    2015-09-01

    Data on the abundance and the ecological-trophic structure of bacterioplankton and bacteriobenthos communities in the Amur Liman and adjacent waters collected in June 2007 have been compared to the relevant data of 2006. Interyear changes of bacterioplankton abundance have been found to depend on the intensity of the Amur River runoff. Correlation analysis has revealed a negative dependence of the abundance of bacterioplankton, bacteriobenthos, and their ecological-trophic groups on water salinity, as well as direct relations between these biotic components and organic matter in water and bottom sediments. The microbiological indicators of water quality ranked the studied waters as classes III-IV in 2006 and as classes II-III in 2007. The high total abundance of bacteriobenthos (109-1010 cells/g) is a result of the functioning of a marginal filter rather than the direct pollution of the liman.

  15. Evidence for a thick oceanic crust adjacent to the Norwegian Margin

    NASA Astrophysics Data System (ADS)

    Mutter, John C.; Talwani, Manik; Stoffa, Paul L.

    1984-01-01

    The oceanic crust created during this first few million years of accretion in the Norwegian-Greenland Sea lies at an unusually shallow depth for its age, has a smooth upper surface, and in many places the results of multichannel seismic reflection profiling reveal that its upper layers comprise a remarkable sequence of arcuate, seaward-dipping reflectors. These have been attributed to lava flows generated during a brief period of subaerial seafloor spreading. We describe the results of inversions of digitally recorded sonobuoy measurements and two-ship expanded spread profiles collected over the oceanic crust adjacent to the Norwegian passive margin. We find that the crust of the deep Lofoten Basin is indistinguishable from normal oceanic crust in thickness and structure. Closer to the margin we observe up to a four times expansion in thickness of layers with velocities equal to those of oceanic layer 2, while the layer 3 region retains approximately the same thickness. The area over which the seaward-dipping reflectors can be observed on reflection profiles corresponds to the region of greatest expansion in "Layer 2" thickness. In the very oldest crust immediately adjacent to an escarpment that probably marks the continent-ocean boundary, we see evidence for a low velocity zone overlying an indistinct reflector that may mark the dyke-lava interface in the thick crust. Comparing the structure of the thick crust to that of eastern Iceland, we find a strong resemblance, especially in the expansion in thickness of material with layer 2 velocities. These results support the suggestion that during the earliest stages of spreading extrusive volcanism at the ridge crest was unusually voluminous, building a thick pile of lavas erupted from a subaerial spreading center.

  16. Tidally influenced alongshore circulation at an inlet-adjacent shoreline

    USGS Publications Warehouse

    Hansen, Jeff E.; Elias, Edwin P.L.; List, Jeffrey H.; Erikson, Li H.; Barnard, Patrick L.

    2013-01-01

    The contribution of tidal forcing to alongshore circulation inside the surfzone is investigated at a 7 km long sandy beach adjacent to a large tidal inlet. Ocean Beach in San Francisco, CA (USA) is onshore of a ∼150 km2 ebb-tidal delta and directly south of the Golden Gate, the sole entrance to San Francisco Bay. Using a coupled flow-wave numerical model, we find that the tides modulate, and in some cases can reverse the direction of, surfzone alongshore flows through two separate mechanisms. First, tidal flow through the inlet results in a barotropic tidal pressure gradient that, when integrated across the surfzone, represents an important contribution to the surfzone alongshore force balance. Even during energetic wave conditions, the tidal pressure gradient can account for more than 30% of the total alongshore pressure gradient (wave and tidal components) and up to 55% during small waves. The wave driven component of the alongshore pressure gradient results from alongshore wave height and corresponding setup gradients induced by refraction over the ebb-tidal delta. Second, wave refraction patterns over the inner shelf are tidally modulated as a result of both tidal water depth changes and strong tidal flows (∼1 m/s), with the effect from currents being larger. These tidally induced changes in wave refraction result in corresponding variability of the alongshore radiation stress and pressure gradients within the surfzone. Our results indicate that tidal contributions to the surfzone force balance can be significant and important in determining the direction and magnitude of alongshore flow.

  17. Tidally influenced alongshore circulation at an inlet-adjacent shoreline

    NASA Astrophysics Data System (ADS)

    Hansen, Jeff E.; Elias, Edwin; List, Jeffrey H.; Erikson, Li H.; Barnard, Patrick L.

    2013-03-01

    The contribution of tidal forcing to alongshore circulation inside the surfzone is investigated at a 7 km long sandy beach adjacent to a large tidal inlet. Ocean Beach in San Francisco, CA (USA) is onshore of a ˜150 km2 ebb-tidal delta and directly south of the Golden Gate, the sole entrance to San Francisco Bay. Using a coupled flow-wave numerical model, we find that the tides modulate, and in some cases can reverse the direction of, surfzone alongshore flows through two separate mechanisms. First, tidal flow through the inlet results in a barotropic tidal pressure gradient that, when integrated across the surfzone, represents an important contribution to the surfzone alongshore force balance. Even during energetic wave conditions, the tidal pressure gradient can account for more than 30% of the total alongshore pressure gradient (wave and tidal components) and up to 55% during small waves. The wave driven component of the alongshore pressure gradient results from alongshore wave height and corresponding setup gradients induced by refraction over the ebb-tidal delta. Second, wave refraction patterns over the inner shelf are tidally modulated as a result of both tidal water depth changes and strong tidal flows (˜1 m/s), with the effect from currents being larger. These tidally induced changes in wave refraction result in corresponding variability of the alongshore radiation stress and pressure gradients within the surfzone. Our results indicate that tidal contributions to the surfzone force balance can be significant and important in determining the direction and magnitude of alongshore flow.

  18. The influence of vortex pinning and grain boundary structure on critical currents across grain boundaries in YBa{sub 2}Cu{sub 3}O{sub x}.

    SciTech Connect

    Miller, D. J.

    1998-10-27

    We have used studies of single grain boundaries in YBCO thin films and bulk bicrystals to study the influence of vortex pinning along a grain boundary on dissipation. The critical current density for transport across grain boundaries in thin films is typically more than an order of magnitude larger than that measured for transport across grain boundaries in bulk samples. For low disorientation angles, the difference in critical current density within the grains that form the boundary can contribute to the substantial differences in current density measured across the boundary. However, substantial differences exist in the critical current density across boundaries in thin film compared to bulk bicrystals even in the higher angle regime in which grain boundary dissipation dominates. The differences in critical current density in this regime can be understood on the basis of vortex pinning along the boundary.

  19. Are Hot Spots between Two Plasmonic Nanocubes of Silver or Gold Formed between Adjacent Corners or Adjacent Facets? A DDA Examination.

    PubMed

    Hooshmand, Nasrin; Bordley, Justin A; El-Sayed, Mostafa A

    2014-07-01

    Of all the plasmonic solid nanoparticles, single Ag or Au nanocubes are known to be plasmonic nanoparticles with strong plasmonic fields, which are concentrated around their corners. However, when nanoparticles aggregate, they do so in a face-to face arrangement. The formation of hot spots between plasmonic nanoparticles in close proximity to each other is known to greatly enhance their plasmonic fields which are important in the field of imaging. Thus, what is the structural development of hot spots between two nanocubes in a dimer? Do they form between the corners or are they between the adjacent facets, and what does this depend on? A detailed discrete dipole approximation (DDA) simulation of Au-Au and Ag-Ag dimers suggests that there is a competition between their formation in these two locations, which depends on the polarization direction of the exciting light (with respect to the interparticle axis in the dimer), its intensity and the wavelength as well as the interparticle separation of the dimer. PMID:26279539

  20. Pathogenesis of the discal cysts communicating with an adjacent herniated disc. Histological and ultrastructual studies of two cases.

    PubMed

    Kobayashi, Shigeru; Takeno, Kenichi; Uchida, Kenzo; Yayama, Takafumi; Nakajima, Hideaki; Miyazaki, Tsuyoshi; Guerrero, Alexander; Baba, Hisatoshi

    2010-03-01

    Discal cyst of the lumbar spine is a very rare cause of back pain and sciatica. We report two cases of discal cysts communicating with an adjacent herniated disc. From CT and MRI findings, they were diagnosed as having a discal cyst in the epidural space, which compressed the nerve root. After an adequate surgical field was obtained with a microscope and a Casper retractor, the discal cyst could be excised and satisfactory decompression of the adjacent nerve root was obtained. From histological and electron microscopic study, the presence of residual herniated tissues was confirmed in the cyst wall. Macrophages played an important role in the absorption of herniated tissue and the formation of the discal cyst. Hemorrhage in the cyst wall will make the serous hemorrhagic fluid-filled cystic structure in the absorbed spaces of the prolapsed disc. In this study, we confirmed that the discal cyst could have developed from the absorption process of a disc herniation. PMID:20138794

  1. Physical, Structural and Operational Vulnerability of Critical Facilities in Valle de Chalco Solidaridad, Estado de Mexico, Mexico. Case of study: Avándaro, San Isidro and El Triunfo

    NASA Astrophysics Data System (ADS)

    Garcia Payne, D. G.; Novelo-Casanova, D. A.; Ponce-Pacheco, A. B.; Espinosa-Campos, O.; Huerta-Parra, M.; Reyes-Pimentel, T.; Rodriguez, F.; Benitez-Olivares, I.

    2010-12-01

    Valle de Chalco Solidaridad is located in Mexico City Metropolitan Area in Estado de Mexico, Mexico. In this town there is a sewage canal called “La Compañía”. A wall of this canal collapsed on February 5, 2010 due to heavy rains creating the flooding of four surrounding communities. It is important to point out that this area is frequently exposed to floods. In this work, we consider a critical facility as an essential structure for performance, health care and welfare within a community or/and as a place that can be used as shelter in case of emergency or disaster. Global vulnerability (the sum of the three measured vulnerabilities) of the 25 critical facilities identified in the locations of Avándaro, San Isidro and El Triunfo was assessed using the Community Vulnerability Assessment Tool developed by the National Oceanic and Atmospheric Administration (NOAA). For each critical facility we determined its operational, structural and physical vulnerabilities. For our analysis, we considered the four main natural hazards to which Valle de Chalco is exposed: earthquakes, floods, landslides and sinking. We considered five levels of vulnerability using a scale from 1 to 5, where values range from very low to very high vulnerability, respectively. A critical facilities database was generated by collecting general information for three categories: schools, government and church. Each facility was evaluated considering its location in relation to identified high-risk areas. Our results indicate that in average, the global vulnerability of all facilities is low, however, there are particular cases in which this global vulnerability is high. The average operational vulnerability of the three communities is moderate. The global structural vulnerability (sum of the structural vulnerability for the four analyzed hazards) is moderate. In particular, the structural vulnerability to earthquakes is low, to landslides is very low, to flooding is moderate and to sinking is

  2. Trace element fingerprinting of cockle (Cerastoderma edule) shells can reveal harvesting location in adjacent areas.

    PubMed

    Ricardo, Fernando; Génio, Luciana; Costa Leal, Miguel; Albuquerque, Rui; Queiroga, Henrique; Rosa, Rui; Calado, Ricardo

    2015-01-01

    Determining seafood geographic origin is critical for controlling its quality and safeguarding the interest of consumers. Here, we use trace element fingerprinting (TEF) of bivalve shells to discriminate the geographic origin of specimens. Barium (Ba), manganese (Mn), magnesium (Mg), strontium (Sr) and lead (Pb) were quantified in cockle shells (Cerastoderma edule) captured with two fishing methods (by hand and by hand-raking) and from five adjacent fishing locations within an estuarine system (Ria de Aveiro, Portugal). Results suggest no differences in TEF of cockle shells captured by hand or by hand-raking, thus confirming that metal rakes do not act as a potential source of metal contamination that could somehow bias TEF results. In contrast, significant differences were recorded among locations for all trace elements analysed. A Canonical Analysis of Principal Coordinates (CAP) revealed that 92% of the samples could be successfully classified according to their fishing location using TEF. We show that TEF can be an accurate, fast and reliable method to determine the geographic origin of bivalves, even among locations separated less than 1 km apart within the same estuarine system. Nonetheless, follow up studies are needed to determine if TEF can reliably discriminate between bivalves originating from different ecosystems. PMID:26149418

  3. Late Quaternary history of the southwestern St. Lawrence Lowlands and adjacent Adirondack Highlands

    SciTech Connect

    Pair, D.L. . Dept. of Geology)

    1993-03-01

    The reconstruction of Late Wisconsinan ice retreat, proglacial lakes, and Champlain Sea history from the northwest Adirondack slope and adjacent St. Lawrence Lowlands is critical to the synthesis of a regional picture of deglacial events in the eastern Great Lakes region. Unfortunately, these same areas are well known for their limited exposures, landforms covered by thick forest, large tracts of land inaccessible to detailed field mapping, and the overall paucity of glacial materials preserved on upland surfaces. Despite these limitations, a model which utilizes multiple and field-truthed evidence has been used to designate areas where ice border deposits indicate a substantial recessional position. It employs the following criteria in this analysis: sedimentology and morphostratigraphy of morainal landform segments and related sediments; orientation and continuity of ice border drainage channels; and the relationship of ice borders and drainage systems to well documented local and regional water bodies which accompanied ice retreat. The results of this approach have provided a unique regional picture of deglaciation. Despite the inherent limitations of working in upland areas to reconstruct glacial events, detailed morphostratigraphic correlations based on multiple lines of evidence can yield important information. The positions of five former ice borders have been reconstructed from the available data. These ice margins correspond closely with those documented previously by others adjoining areas. This type of study, utilizing multiple and field-truthed lines of evidence, constitutes a tangible step towards understanding the nature and history of ice retreat along this portion of the Laurentide Ice Sheet.

  4. A plot tree structure to represent surface flow connectivity in rural catchments: definition and application for mining critical source areas and temporal conditions

    NASA Astrophysics Data System (ADS)

    Gascuel-Odoux, Chantal; Cordier, Marie-Odile; Grimaldi, Catherine; Salmon-Monviola, Jordy; Masson, Veronique; Squividant, Herve; Trepos, Ronan

    2013-04-01

    ., Tortrat F., Cordier M.O., 2009. A plot drainage network as a conceptual tool for the spatial representation of surface flow pathways in agricultural catchments. Computer and Geosciences, 35, 276-288. Gascuel-Odoux C., Aurousseau P., Cordier M.O., Durand P., Garcia F., Masson, V., Salmon-Monviola J., Tortrat F., Trepos, R. 2009. A decision-oriented model to evaluate the effect of land use and management on herbicide contamination in stream water. Environmental modelling and software, 24, 1433-1446. Gascuel-Odoux C., Aurousseau, P., Doray, T., Squividant, H., Macary, F., Uny, D., Grimaldi, C., 2011. Incorporating landscape features in a plot tree structure to represent surface flow connectivity in rural catchments. Hydrological Processes, 25, 3625-3636. Salmon-Monviola J., Gascuel-Odoux C., Garcia F., Tortrat F., Cordier M.O., Masson V., Trepos R., 2011. Simulating the effect of technical and environmental constraints on the spatio-temporal distribution of herbicide applications and stream losses. Agriculture, Environment and Ecosystems, 140, 382-394. Trepos, R., Masson V., Cordier, M.O., Gascuel-Odoux, C., Salmon-Monviola J., 2012. Mining simulation data by rule induction to determine critical source areas of stream water pollution by herbicides. Computers and Electronics in Agriculture 86: 75-88.

  5. Results of en bloc resection for hepatocellular carcinoma extending to adjacent organs

    PubMed Central

    Zhou, Yan-Ming; Sui, Cheng-Jun; Li, Bin; Xu, Feng; Kan, Tong; Yang, Jia-Mei

    2012-01-01

    Background To curatively resect hepatocellular carcinoma (HCC) with adjacent organ extension, the combined resection of these organs is inevitable. We analyzed the safety and effectiveness of en bloc resection for HCC extending to adjacent organs. Methods From December 2002 to May 2006, we compared the surgical outcomes of patients with HCC extending to adjacent organs with those of closely matched, randomly selected patients with HCC without adjacent organ extension. Results We included 42 patients whose HCC extended to adjacent organs and 126 patients whose HCC did not extend to adjacent organs. There was no significant difference in survival, operative morbidity or mortality between the groups. In patients with HCC extending to adjacent organs, histopathological examination of the specimen revealed true tumour invasion in 13 and adhesion in 29 patients. Those with tumour invasion were more likely to have a high incidence of capsule infiltration, microvascular invasion and early intrahepatic recurrence (≤ 1 yr after hepatectomy). The 5-year overall survival of patients with tumour invasion was 11.5%, whereas that of patients with tumour adhesion was 38.1% (p = 0.033). Conclusion En bloc resection is a safe and effective therapy for HCC extending to adjacent organs. Tumour invasion to adjacent organs exhibits a more aggressive clinical behaviour and is associated with worse survival than tumour adhesion. PMID:22617536

  6. Stabilities of ant nests and their adjacent soils

    NASA Astrophysics Data System (ADS)

    Echezona, B. C.; Igwe, C. A.

    2012-10-01

    Nests habour ants and termites and protect them from harsh environmental conditions. The structural stabilities of nests were studied to ascertain their relative vulnerability to environmental stresses. Arboreal-ant nests were pried from different trees, while epigeous-termite nests were excavated from soil surface within the sample area. Soils without any visible sign of ant or termite activity were also sampled 6 m away from the nests as control. Laboratory analysis result showed that irrespective of the tree hosts, the aggregate stabilities of the ant nests were lower than those of the ground termite, with nests formed on Cola nitida significantly showing lower aggregate stability (19.7%) than other antnest structures. Clay dispersion ratio, moisture content, water stable aggregate class <0.25mm and sand mass were each negatively correlated with aggregate stability, while water stable aggregate class1.00-0.50 mm gave a positive correlation. Nest structures were dominated more by water stable aggregate class >2.00 mm but path analysis demonstrated that water stable aggregate class <0.25 mm contributed most to the higher aggregate stability of the termite nest than the other nest. Nest aggregates had greater structural stability compared to the control soil. The higher structural stability of termite nests over other nest and soil was considered a better adaptive mechanism against body desiccation.

  7. Critical Pedagogy for Critical Mathematics Education

    ERIC Educational Resources Information Center

    Tutak, Fatma Aslan; Bondy, Elizabeth; Adams, Thomasenia L.

    2011-01-01

    This article provides a brief introduction to critical pedagogy and further discussion on critical mathematics education. Critical mathematics education enables students to read the world with mathematics. Three emerging domains of mathematics education related to critical mathematics education are discussed in this manuscript: ethnomathematics,…

  8. Assessment of Bacterial bph Gene in Amazonian Dark Earth and Their Adjacent Soils

    PubMed Central

    Brossi, Maria Julia de Lima; Mendes, Lucas William; Germano, Mariana Gomes; Lima, Amanda Barbosa; Tsai, Siu Mui

    2014-01-01

    Amazonian Anthrosols are known to harbour distinct and highly diverse microbial communities. As most of the current assessments of these communities are based on taxonomic profiles, the functional gene structure of these communities, such as those responsible for key steps in the carbon cycle, mostly remain elusive. To gain insights into the diversity of catabolic genes involved in the degradation of hydrocarbons in anthropogenic horizons, we analysed the bacterial bph gene community structure, composition and abundance using T-RFLP, 454-pyrosequencing and quantitative PCR essays, respectively. Soil samples were collected in two Brazilian Amazon Dark Earth (ADE) sites and at their corresponding non-anthropogenic adjacent soils (ADJ), under two different land use systems, secondary forest (SF) and manioc cultivation (M). Redundancy analysis of T-RFLP data revealed differences in bph gene structure according to both soil type and land use. Chemical properties of ADE soils, such as high organic carbon and organic matter, as well as effective cation exchange capacity and pH, were significantly correlated with the structure of bph communities. Also, the taxonomic affiliation of bph gene sequences revealed the segregation of community composition according to the soil type. Sequences at ADE sites were mostly affiliated to aromatic hydrocarbon degraders belonging to the genera Streptomyces, Sphingomonas, Rhodococcus, Mycobacterium, Conexibacter and Burkholderia. In both land use sites, shannon's diversity indices based on the bph gene data were higher in ADE than ADJ soils. Collectively, our findings provide evidence that specific properties in ADE soils shape the structure and composition of bph communities. These results provide a basis for further investigations focusing on the bio-exploration of novel enzymes with potential use in the biotechnology/biodegradation industry. PMID:24927167

  9. Assessment of bacterial bph gene in Amazonian dark earth and their adjacent soils.

    PubMed

    Brossi, Maria Julia de Lima; Mendes, Lucas William; Germano, Mariana Gomes; Lima, Amanda Barbosa; Tsai, Siu Mui

    2014-01-01

    Amazonian Anthrosols are known to harbour distinct and highly diverse microbial communities. As most of the current assessments of these communities are based on taxonomic profiles, the functional gene structure of these communities, such as those responsible for key steps in the carbon cycle, mostly remain elusive. To gain insights into the diversity of catabolic genes involved in the degradation of hydrocarbons in anthropogenic horizons, we analysed the bacterial bph gene community structure, composition and abundance using T-RFLP, 454-pyrosequencing and quantitative PCR essays, respectively. Soil samples were collected in two Brazilian Amazon Dark Earth (ADE) sites and at their corresponding non-anthropogenic adjacent soils (ADJ), under two different land use systems, secondary forest (SF) and manioc cultivation (M). Redundancy analysis of T-RFLP data revealed differences in bph gene structure according to both soil type and land use. Chemical properties of ADE soils, such as high organic carbon and organic matter, as well as effective cation exchange capacity and pH, were significantly correlated with the structure of bph communities. Also, the taxonomic affiliation of bph gene sequences revealed the segregation of community composition according to the soil type. Sequences at ADE sites were mostly affiliated to aromatic hydrocarbon degraders belonging to the genera Streptomyces, Sphingomonas, Rhodococcus, Mycobacterium, Conexibacter and Burkholderia. In both land use sites, shannon's diversity indices based on the bph gene data were higher in ADE than ADJ soils. Collectively, our findings provide evidence that specific properties in ADE soils shape the structure and composition of bph communities. These results provide a basis for further investigations focusing on the bio-exploration of novel enzymes with potential use in the biotechnology/biodegradation industry. PMID:24927167

  10. The lithosphere of Ellesmere Island and adjacent northwestern Greenland (CALE 'A' transect onshore)

    NASA Astrophysics Data System (ADS)

    Stephenson, R.; Schiffer, C.; Oakey, G. N.

    2013-12-01

    Ellesmere Island, in Canada's Arctic, comprises a series of ~SW-NE trending tectonic provinces, the crustal structure and geological expression of which represent a combination of interplate, accretionary orogenesis in the Palaeozoic (Caledonian equivalent and Ellesmerian orogenies) and intraplate orogenesis in the Cenozoic (Eurekan Orogeny). The present-day topography of Ellesmere Island is closely related to the crustal architecture of these tectonic provinces, which includes the adjacent polar continental margin. A two-dimensional lithosphere-scale model is presented that crosses Ellesmere Island from northern Baffin Bay to the Arctic Ocean, part of Transect 'A' of the Circum-Arctic Lithosphere Evolution (CALE) project. The model is based on gravity and magnetic data constrained by mapped geological structure as well as a not yet unpublished Receiver Function study, based on teleseismic data acquired between 2010 and 2012 by a passive seismological array on Ellesmere Island called 'ELLITE'. In northern Baffin Bay and on parts of the polar margin of Ellesmere Island (and adjacent northwestern Greenland), published crustal scale seismic refraction velocity models also provide some constraint to the lithosphere model. The most recent tectonic event governing the geological and physiographic character of Ellesmere Island is the Eurekan Orogeny, an intraplate orogeny that developed as a consequence of North Atlantic-Arctic plate reorganisations and the resulting convergence of Greenland against Ellesmere Island in the Palaeogene. The basement of the Eurekan orogen comprises Precambrian-aged lithosphere in its northernmost (Pearya terrane) and southeasternmost (Greenland-Canada craton) parts as well as possibly younger lithosphere accreted during Palaeozoic orogenesis in central Ellesmere Island. Its southern margin, marking the southern terminus of the constructed lithosphere model, comprises the late Precambrian-Early Palaeozoic passive continental margin of

  11. The Structure and the Criterion-Related Validity of the Copes Test of Critical Terms and the Copes Test of Science Concepts.

    ERIC Educational Resources Information Center

    Shah, Rashid Ahmed

    Two tests used in the evaluation of the Conceptually Oriented Program in Elementary Science were analyzed by using the responses of 341 children. The COPES Test of Science Concepts and the COPES Test of Critical Terms were both shown to have a high content validity. Item analysis data showed that not all items in the tests discriminated…

  12. Global Citizenship as Education for Peacebuilding in a Divided Society: Structural and Contextual Constraints on the Development of Critical Dialogic Discourse in Schools

    ERIC Educational Resources Information Center

    Reilly, Jacqueline; Niens, Ulrike

    2014-01-01

    In post-conflict and divided societies, global citizenship education has been described as a central element of peacebuilding education, whereby critical pedagogy is seen as a tool to advance students' thinking, transform their views and promote democratic behaviours. The present study investigates understandings of and attitudes to global…

  13. Critical Configurations of Hard Disks on the Torus

    2013-04-16

    CCHDT constructs and classifies various arrangements of hard disks of a single radius places on the unit square with periodic boundary conditions. Specifially, a given configuration is evolved to the nearest critical point on a smoothed hard disk energy fuction, and is classified by the adjacency matrix of the canonically labelled contact graph.

  14. A numerical study of the plume in Cape Fear River Estuary and adjacent coastal ocean

    NASA Astrophysics Data System (ADS)

    Xia, M.; Xia, L.; Pietrafesa, L. J.

    2006-12-01

    Cape Fear River Estuary (CFRE), located in southeast North Carolina, is the only river estuary system in the state which is directly connected to the Atlantic Ocean. It is also an important nursery for economically and ecologically important juvenile fish, crabs, shrimp, and other species because of the tidal influence and saline waters. In this study, Environmental Fluid Dynamic Code (EFDC) is used to simulate the salinity plume and trajectory distribution at the mouth of the CFRE and adjacent coastal ocean. Prescribed with the climatological freshwater discharge rates in the rivers, the modeling system was used to simulate the salinity plume and trajectory distribution distribution in the mouth of the CFRE under the influence of climatological wind conditions and tidal effect. We analyzed the plume formation processes and the strong relationship between the various plume distributions with respect to the wind and river discharge in the region. The simulations also indicate that strong winds tend to reduce the surface CFRE plume size and distorting the bulge region near the estuary mouth due to enhanced wind induced surface mixing. Even moderate wind speeds could fully reverse the buoyancy-driven plume structure in CFRE under normal river discharge conditions. Tide and the river discharge also are important factors to influence the plume structure. The comparions between the distribution of salinity plume and trajectory also are discussed in the study.

  15. Electrophysiological interaction through the interstitial space between adjacent unmyelinated parallel fibers.

    PubMed Central

    Barr, R C; Plonsey, R

    1992-01-01

    The influence of interstitial or extracellular potentials on propagation usually has been ignored, often through assuming these potentials to be insignificantly different from zero, presumably because both measurements and calculations become much more complex when interstitial interactions are included. This study arose primarily from an interest in cardiac muscle, where it has been well established that substantial interstitial potentials occur in tightly packed structures, e.g., tens of millivolts within the ventricular wall. We analyzed the electrophysiological interaction between two adjacent unmyelinated fibers within a restricted extracellular space. Numerical evaluations made use of two linked core-conductor models and Hodgkin-Huxley membrane properties. Changes in transmembrane potentials induced in the second fiber ranged from nonexistent with large intervening volumes to large enough to initiate excitation when fibers were coupled by interstitial currents through a small interstitial space. With equal interstitial and intracellular longitudinal conductivities and close coupling, the interaction was large enough (induced Vm approximately 20 mV peak-to-peak) that action potentials from one fiber initiated excitation in the other, for the 40-microns radius evaluated. With close coupling but no change in structure, propagation velocity in the first fiber varied from 1.66 mm/ms (when both fibers were simultaneously stimulated) to 2.84 mm/ms (when the second fiber remained passive). Although normal propagation through interstitial interaction is unlikely, the magnitudes of the electrotonic interactions were large and may have a substantial modulating effect on function. Images FIGURE 1 PMID:1600078

  16. Pelagic ciliate communities within the Amundsen Sea polynya and adjacent sea ice zone, Antarctica

    NASA Astrophysics Data System (ADS)

    Jiang, Yong; Liu, Qian; Yang, Eun Jin; Wang, Min; Kim, Tae Wan; Cho, Kyoung-Ho; Lee, SangHoon

    2016-01-01

    Polynyas, areas of open water surrounded by sea ice, are sites of intense primary production and ecological hotspots in the Antarctic Ocean. This study determined the spatial variation in communities of pelagic ciliates in an Amundsen Sea polynya (ASP) and adjacent sea ice zones (SIZ) during austral summer from February to March 2012, and the results were compared with biotic and abiotic environmental factors. The species number, abundance and biomass were higher in the ASP than SIZ. Canonical analysis indicated that the communities in the ASP were distinct from those under the sea ice. The pelagic ciliate community structure was closely correlated with environmental variability. Several primary environmental variables, both alone and in combination, were found to affect community spatial patterns. The ciliate biomasses in the ASP and SIZ areas were both significantly correlated with total and nano-Chl a. This analysis of the ciliated microzooplankton communities associated with high primary production provides new insights into the roles of ciliates in biogeochemical cycles in high-latitude polynyas. Additionally, our findings provide detailed data on the composition, distribution, and structure of polynya ciliate communities in the Amundsen Sea.

  17. Variable length adjacent partitioning for PTS based PAPR reduction of OFDM signal

    NASA Astrophysics Data System (ADS)

    Ibraheem, Zeyid T.; Rahman, Md. Mijanur; Yaakob, S. N.; Razalli, Mohammad Shahrazel; Kadhim, Rasim A.

    2015-05-01

    Peak-to-Average power ratio (PAPR) is a major drawback in OFDM communication. It leads the power amplifier into nonlinear region operation resulting into loss of data integrity. As such, there is a strong motivation to find techniques to reduce PAPR. Partial Transmit Sequence (PTS) is an attractive scheme for this purpose. Judicious partitioning the OFDM data frame into disjoint subsets is a pivotal component of any PTS scheme. Out of the existing partitioning techniques, adjacent partitioning is characterized by an attractive trade-off between cost and performance. With an aim of determining effects of length variability of adjacent partitions, we performed an investigation into the performances of a variable length adjacent partitioning (VL-AP) and fixed length adjacent partitioning in comparison with other partitioning schemes such as pseudorandom partitioning. Simulation results with different modulation and partitioning scenarios showed that fixed length adjacent partition had better performance compared to variable length adjacent partitioning. As expected, simulation results showed a slightly better performance of pseudorandom partitioning technique compared to fixed and variable adjacent partitioning schemes. However, as the pseudorandom technique incurs high computational complexities, adjacent partitioning schemes were still seen as favorable candidates for PAPR reduction.

  18. 33 CFR 334.70 - Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations. 334.70 Section 334.70 Navigation and Navigable Waters CORPS... REGULATIONS § 334.70 Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations. (a)...

  19. 33 CFR 334.70 - Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations. 334.70 Section 334.70 Navigation and Navigable Waters CORPS... REGULATIONS § 334.70 Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations. (a)...

  20. 33 CFR 334.70 - Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations. 334.70 Section 334.70 Navigation and Navigable Waters CORPS... REGULATIONS § 334.70 Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations. (a)...