Science.gov

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. Brick incinerator structure located adjacent to "motor courts." This example ...

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

    Brick incinerator structure located adjacent to "motor courts." This example is located between Buildings 26 and 27. Facing northeast - Harbor Hills Housing Project, 26607 Western Avenue, Lomita, Los Angeles County, CA

  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. Atrophy of hippocampal subfields and adjacent extrahippocampal structures in dementia with Lewy bodies and Alzheimer's disease.

    PubMed

    Delli Pizzi, Stefano; Franciotti, Raffaella; Bubbico, Giovanna; Thomas, Astrid; Onofrj, Marco; Bonanni, Laura

    2016-04-01

    The hippocampus and adjacent extrahippocampal structures are organized in distinct and specialized regions which process heterogeneous functions, including memory, and visuospatial functions. Specific alterations of the different hippocampal subfields and adjacent extrahippocampal structures could differently contribute to the pathophysiology of Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). Based on visual symptoms which characterize DLB patients, the hippocampal subfields and the adjacent extrahippocampal structures which are mainly involved in the visual functions could be impaired in DLB and preserved in AD. To test this hypothesis, we performed structural magnetic resonance imaging on 19 DLB, 15 AD, and 19 age-matched healthy controls. FreeSurfer's pipelines were used to perform parcellation of hippocampus and adjacent extrahippocampal structures and to assess the structural changes within each region. The cornu ammonis and subiculum were bilaterally damaged in AD and preserved in DLB. The perirhinal cortex and parahippocampus were damaged in DLB but not in AD. Our findings demonstrate that the hippocampal subfields and adjacent extrahippocampal structures were differently altered in AD and DLB. Particularly, DLB patients showed a more focused alteration of the extrahippocampal structures linked to visual functions.

  5. Structural Requirements of HDAC Inhibitors: SAHA Analogs Functionalized Adjacent to the Hydroxamic Acid

    PubMed Central

    Bieliauskas, Anton V.; Weerasinghe, Sujith V. W.; Pflum, Mary Kay H.

    2007-01-01

    Inhibitors of histone deacetylase (HDAC) proteins such as suberoylanilide hydroxamic acid (SAHA) have emerged as effective therapeutic anti-cancer agents. To better understand the structural requirements of HDAC inhibitors, a small molecule library with a variety of substituents attached adjacent to the metal binding hydroxamic acid of SAHA was synthesized. The presence of a substituent adjacent to the hydroxamic acid led to an 800 to 5000-fold decrease in inhibition compared to SAHA. The observed results have implications for drug design, suggesting that HDAC inhibitors with substituents near the metal binding moiety will have inhibitory activities in the μM rather than nM range. PMID:17307359

  6. Geomorphology and structural geology of Saturnalia Fossae and adjacent structures in the northern hemisphere of Vesta

    NASA Astrophysics Data System (ADS)

    Scully, Jennifer E. C.; Yin, A.; Russell, C. T.; Buczkowski, D. L.; Williams, D. A.; Blewett, D. T.; Ruesch, O.; Hiesinger, H.; Le Corre, L.; Mercer, C.; Yingst, R. A.; Garry, W. B.; Jaumann, R.; Roatsch, T.; Preusker, F.; Gaskell, R. W.; Schröder, S. E.; Ammannito, E.; Pieters, C. M.; Raymond, C. A.

    2014-12-01

    Vesta is a unique, intermediate class of rocky body in the Solar System, between terrestrial planets and small asteroids, because of its size (average radius of ∼263 km) and differentiation, with a crust, mantle and core. Vesta's low surface gravity (0.25 m/s2) has led to the continual absence of a protective atmosphere and consequently impact cratering and impact-related processes are prevalent. Previous work has shown that the formation of the Rheasilvia impact basin induced the equatorial Divalia Fossae, whereas the formation of the Veneneia impact basin induced the northern Saturnalia Fossae. Expanding upon this earlier work, we conducted photogeologic mapping of the Saturnalia Fossae, adjacent structures and geomorphic units in two of Vesta's northern quadrangles: Caparronia and Domitia. Our work indicates that impact processes created and/or modified all mapped structures and geomorphic units. The mapped units, ordered from oldest to youngest age based mainly on cross-cutting relationships, are: (1) Vestalia Terra unit, (2) cratered highlands unit, (3) Saturnalia Fossae trough unit, (4) Saturnalia Fossae cratered unit, (5) undifferentiated ejecta unit, (6) dark lobate unit, (7) dark crater ray unit and (8) lobate crater unit. The Saturnalia Fossae consist of five separate structures: Saturnalia Fossa A is the largest (maximum width of ∼43 km) and is interpreted as a graben, whereas Saturnalia Fossa B-E are smaller (maximum width of ∼15 km) and are interpreted as half grabens formed by synthetic faults. Smaller, second-order structures (maximum width of <1 km) are distinguished from the Saturnalia Fossae, a first-order structure, by the use of the general descriptive term 'adjacent structures', which encompasses minor ridges, grooves and crater chains. For classification purposes, the general descriptive term 'minor ridges' characterizes ridges that are not part of the Saturnalia Fossae and are an order of magnitude smaller (maximum width of <1 km vs

  7. 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.

  8. Extended polyglutamine tracts cause aggregation and structural perturbation of an adjacent beta barrel protein.

    PubMed

    Ignatova, Zoya; Gierasch, Lila M

    2006-05-05

    Formation of fibrillar intranuclear inclusions and related neuropathologies of the CAG-repeat disorders are linked to the expansion of a polyglutamine tract. Despite considerable effort, the etiology of these devastating diseases remains unclear. Although polypeptides with glutamine tracts recapitulate many of the observed characteristics of the gene products with CAG repeats, such as in vitro and in vivo aggregation and toxicity in model organisms, extended polyglutamine segments have also been reported to structurally perturb proteins into which they are inserted. Additionally, the sequence context of a polyglutamine tract has recently been shown to modulate its propensity to aggregate. These findings raise the possibility that indirect influences of the repeat tract on adjacent protein domains are contributory to pathologies. Destabilization of an adjacent domain may lead to loss of function, as well as favoring non-native structures in the neighboring domain causing them to be prone to intermolecular association and consequent aggregation. To explore these phenomena, we have used chimeras of a well studied globular protein and exon 1 of huntingtin. We find that expansion of the polyglutamine segment beyond the pathological threshold (>35 glutamines) results in structural perturbation of the neighboring protein whether the huntingtin exon is N- or C-terminal. Elongation of the polyglutamine region also substantially increases the propensity of the chimera to aggregate, both in vitro and in vivo, and in vitro aggregation kinetics of a chimera with a 53-glutamine repeat follow a nucleation polymerization mechanism with a monomeric nucleus.

  9. Multiscale bi-Gaussian filter for adjacent curvilinear structures detection with application to vasculature images.

    PubMed

    Xiao, Changyan; Staring, Marius; Wang, Yaonan; Shamonin, Denis P; Stoel, Berend C

    2013-01-01

    The intensity or gray-level derivatives have been widely used in image segmentation and enhancement. Conventional derivative filters often suffer from an undesired merging of adjacent objects because of their intrinsic usage of an inappropriately broad Gaussian kernel; as a result, neighboring structures cannot be properly resolved. To avoid this problem, we propose to replace the low-level Gaussian kernel with a bi-Gaussian function, which allows independent selection of scales in the foreground and background. By selecting a narrow neighborhood for the background with regard to the foreground, the proposed method will reduce interference from adjacent objects simultaneously preserving the ability of intraregion smoothing. Our idea is inspired by a comparative analysis of existing line filters, in which several traditional methods, including the vesselness, gradient flux, and medialness models, are integrated into a uniform framework. The comparison subsequently aids in understanding the principles of different filtering kernels, which is also a contribution of this paper. Based on some axiomatic scale-space assumptions, the full representation of our bi-Gaussian kernel is deduced. The popular γ-normalization scheme for multiscale integration is extended to the bi-Gaussian operators. Finally, combined with a parameter-free shape estimation scheme, a derivative filter is developed for the typical applications of curvilinear structure detection and vasculature image enhancement. It is verified in experiments using synthetic and real data that the proposed method outperforms several conventional filters in separating closely located objects and being robust to noise.

  10. Laramide structure of the central Sangre de Cristo Mountains and adjacent Raton Basin, southern Colorado

    USGS Publications Warehouse

    Lindsey, D.A.

    1998-01-01

    Laramide structure of the central Sangre de Cristo Mountains (Culebra Range) is interpreted as a system of west-dipping, basement-involved thrusts and reverse faults. The Culebra thrust is the dominant structure in the central part of the range; it dips 30 -55?? west and brings Precambrian metamorphic base-ment rocks over unmetamorphosed Paleozoic rocks. East of the Culebra thrust, thrusts and reverse faults break the basement and overlying cover rocks into north-trending fault blocks; these boundary faults probably dip 40-60?? westward. The orientation of fault slickensides indicates oblique (northeast) slip on the Culebra thrust and dip-slip (ranging from eastward to northward) movement on adjacent faults. In sedimentary cover rocks, east-vergent anticlines overlie and merge with thrusts and reverse faults; these anticlines are interpreted as fault-propagation folds. Minor east-dipping thrusts and reverse faults (backthrusts) occur in both the hanging walls and footwalls of thrusts. The easternmost faults and folds of the Culebra Range form a continuous structural boundary between the Laramide Sangre de Cristo highland and the Raton Basin. Boundary structures consist of west-dipping frontal thrusts flanked on the basinward side by poorly exposed, east-dipping backthrusts. The backthrusts are interpreted to overlie structural wedges that have been emplaced above blind thrusts in the basin margin. West-dipping frontal thrusts and blind thrusts are interpreted to involve basement, but backthrusts are rooted in basin-margin cover rocks. At shallow structural levels where erosion has not exposed a frontal thrust, the structural boundary of the basin is represented by an anticline or monocline. Based on both regional and local stratigraphic evidence, Laramide deformation in the Culebra Range and accompanying synorogenic sedimentation in the western Raton Basin probably took place from latest Cretaceous through early Eocene time. The earliest evidence of uplift and

  11. 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

  12. A modified Kelvin impact model for pounding simulation of base-isolated building with adjacent structures

    NASA Astrophysics Data System (ADS)

    Ye, Kun; Li, Li; Zhu, Hongping

    2009-09-01

    Base isolation can effectively reduce the seismic forces on a superstructure, particularly in low- to medium-rise buildings. However, under strong near-fault ground motions, pounding may occur at the isolation level between the base-isolated building (BIB) and its surrounding retaining walls. To effectively investigate the behavior of the BIB pounding with adjacent structures, after assessing some commonly used impact models, a modified Kelvin impact model is proposed in this paper. Relevant parameters in the modified Kelvin model are theoretically derived and numerically verified through a simple pounding case. At the same time, inelasticity of the isolated superstructure is introduced in order to accurately evaluate the potential damage to the superstructure caused by the pounding of the BIB with adjacent structures. The reliability of the modified Kelvin impact model is validated through numerical comparisons with other impact models. However, the difference between the numerical results from the various impact analytical models is not significant. Many numerical simulations of BIBs are conducted to investigate the influence of various design parameters and conditions on the peak inter-story drifts and floor accelerations during pounding. It is shown that pounding can substantially increase floor accelerations, especially at the ground floor where impacts occur. Higher modes of vibration are excited during poundings, increasing the inter-story drifts instead of keeping a nearly rigid-body motion of the superstructure. Furthermore, higher ductility demands can be imposed on lower floors of the superstructure. Moreover, impact stiffness seems to play a significant role in the acceleration response at the isolation level and the inter-story drifts of lower floors of the superstructure. Finally, the numerical results show that excessive flexibility of the isolation system used to minimize the floor accelerations may cause the BIB to be more susceptible to pounding

  13. Population structure of harbour porpoises Phocoena phocoena in the seas around the UK and adjacent waters.

    PubMed Central

    Walton, M J

    1997-01-01

    The population structure of harbour porpoises from British and adjacent waters was studied by examining variability in a 200 bp (base pair) section of the control region of mitochondrial DNA (mtDNA) extracted from 327 animals. This region contained 20 variable sites giving rise to 24 different haplotypes. Mean nucleotide diversity between all pairs of haplotypes was 0.81% (range 0-4%). The most common haplotype occurred in 63% of the samples and was recorded in all geographical areas; several other haplotypes were present in two or more of the sampling locations. This suggests considerable historical interconnections among populations, probably through gene flow. However, there were significant differences (p < 0.05) as determined by AMOVA (Analysis of Molecular Variance, Excoffier et al. 1992), between porpoises from the northern and southern North Sea, and between the northern North Sea and the Celtic/Irish Sea. The differences were predominantly due to variation among females. This sex-related difference in population genetic structure suggests that males disperse more than females. This has important consequences for evaluating the consequences of incidental catches of porpoises by fisheries in these seas since there may be a greater impact on local populations than is implied by simple calculations of mortality. PMID:9061964

  14. 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

  15. Seismic analysis of adjacent buildings subjected to double pounding considering soil-structure interaction

    NASA Astrophysics Data System (ADS)

    Farghaly, Ahmed Abdelraheem

    2017-02-01

    A 2D model of two adjacent buildings with different heights (6 and 12 floors) and foundation levels without separation distance under seismic load and considering SSI is investigated. A special arrangement of contact elements (gap elements) each 1 m of the low height building in the contact zone is taken into consideration to fulfill all possible deformation contact modes which take place under seismic load (earthquake). Soil is modeled by 2D shell elements in contact with foundations of the two adjacent buildings. This paper focuses on the study of double pounding that takes place between the two adjacent buildings in some upper points at superstructure in the contact zone and also at foundation level. The forces of double pounding between the two adjacent buildings, which increase by softening of the soil, give a valuable assessment of straining actions of the two adjacent buildings and change the behavior of soil under the foundations and around basement floor.

  16. Seismic analysis of adjacent buildings subjected to double pounding considering soil-structure interaction

    NASA Astrophysics Data System (ADS)

    Farghaly, Ahmed Abdelraheem

    2017-03-01

    A 2D model of two adjacent buildings with different heights (6 and 12 floors) and foundation levels without separation distance under seismic load and considering SSI is investigated. A special arrangement of contact elements (gap elements) each 1 m of the low height building in the contact zone is taken into consideration to fulfill all possible deformation contact modes which take place under seismic load (earthquake). Soil is modeled by 2D shell elements in contact with foundations of the two adjacent buildings. This paper focuses on the study of double pounding that takes place between the two adjacent buildings in some upper points at superstructure in the contact zone and also at foundation level. The forces of double pounding between the two adjacent buildings, which increase by softening of the soil, give a valuable assessment of straining actions of the two adjacent buildings and change the behavior of soil under the foundations and around basement floor.

  17. The effects of 3D bioactive glass scaffolds and BMP-2 on bone formation in rat femoral critical size defects and adjacent bones.

    PubMed

    Liu, Wai-Ching; Robu, Irina S; Patel, Rikin; Leu, Ming C; Velez, Mariano; Chu, Tien-Min Gabriel

    2014-08-01

    Reconstruction of critical size defects in the load-bearing area has long been a challenge in orthopaedics. In the past, we have demonstrated the feasibility of using a biodegradable load-sharing scaffold fabricated from poly(propylene fumarate)/tricalcium phosphate (PPF/TCP) loaded with bone morphogenetic protein-2 (BMP-2) to successfully induce healing in those defects. However, there is limited osteoconduction observed with the PPF/TCP scaffold itself. For this reason, 13-93 bioactive glass scaffolds with local BMP-2 delivery were investigated in this study for inducing segmental defect repairs in a load-bearing region. Furthermore, a recent review on BMP-2 revealed greater risks in radiculitis, ectopic bone formation, osteolysis and poor global outcome in association with the use of BMP-2 for spinal fusion. We also evaluated the potential side effects of locally delivered BMP-2 on the structures of adjacent bones. Therefore, cylindrical 13-93 glass scaffolds were fabricated by indirect selective laser sintering with side holes on the cylinder filled with dicalcium phosphate dehydrate as a BMP-2 carrier. The scaffolds were implanted into critical size defects created in rat femurs with and without 10 μg of BMP-2. The x-ray and micro-CT results showed that a bridging callus was found as soon as three weeks and progressed gradually in the BMP group while minimal bone formation was observed in the control group. Degradation of the scaffolds was noted in both groups. Stiffness, peak load and energy to break of the BMP group were all higher than the control group. There was no statistical difference in bone mineral density, bone area and bone mineral content in the tibiae and contralateral femurs of the control and BMP groups. In conclusion, a 13-93 bioactive glass scaffold with local BMP-2 delivery has been demonstrated for its potential application in treating large bone defects.

  18. The sedimentary and crustal velocity structure of Makarov Basin and adjacent Alpha Ridge

    NASA Astrophysics Data System (ADS)

    Evangelatos, John; Funck, Thomas; Mosher, David C.

    2017-01-01

    This study examines the velocity structure of Makarov Basin and the adjacent Alpha Ridge to determine the tectonic origins of these features and link them to the larger Amerasia Basin. Seismic data from sonobuoys distributed along a 650 km-long line extending from Alpha Ridge and across Makarov Basin to the Lomonosov Ridge were analyzed for this purpose. Forward modelling of traveltimes, supported by coincident multi-channel seismic reflection and shipborne gravity data, were used to determine the P-wave velocity structure along the line. The sedimentary cover averages 0.5 km-thick on Alpha Ridge and 1.9 km-thick in Makarov Basin, but reaches up to 5 km-thick at the base of Lomonosov Ridge. Velocities in the sedimentary section range from 1.6 to 4.3 km s- 1. As suggested by relatively high velocities, interbedded volcaniclastic or volcanic rock may occur in the deep sedimentary section. The shallow basement of Alpha Ridge (3.3 to 3.6 km s- 1) is characterized by semi-continuous high amplitude reflections and is interpreted as volcanic rock possibly intercalated with sedimentary rock. Velocities do not vary significantly in the upper and mid-crustal layers between Alpha Ridge and Makarov Basin. Total crustal thickness decreases from 27 km beneath Alpha Ridge to 5 km-thick in Makarov Basin then thickens to > 20 km over a short distance as part of Lomonosov Ridge. The crustal structure of Alpha Ridge is consistent with previous studies suggesting that the Alpha-Mendeleev ridge complex is part of a large igneous province (LIP) with thick igneous crust. The lack of change in crustal velocities between Alpha Ridge and Makarov Basin suggests that the basin, at least partly, either formed during or was influenced by LIP-related magmatism. The rapid transition of crustal thicknesses from Makarov Basin to Lomonosov Ridge supports the interpretation that this section of the ridge is a transform margin.

  19. 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

  20. 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.

  1. Association between Sacral Slanting and Adjacent Structures in Patients with Adolescent Idiopathic Scoliosis

    PubMed Central

    Lee, Choon Sung; Joo, Youn-Suk; Park, Jungu; Hwang, Chang Ju; Lee, Dong-Ho

    2017-01-01

    Background Sacral slanting is a frequent unique phenomenon in patients with adolescent idiopathic scoliosis (AIS) and may be important for selecting the distal fusion level. However, the reason of the phenomenon remains unknown. The purpose of this study was to determine the association between sacral slanting and adjacent structures in patients with AIS. Methods A total of 303 AIS patients who underwent both whole spine standing anteroposterior (AP) and whole leg standing AP radiography were included. The degree of sacral slanting, pelvic obliquity, lumbar curve angles (L1-L4), and L4 tilt were assessed on whole spine standing AP radiographs. Whole leg standing AP radiographs were used to assess the degree of leg length discrepancy (LLD). Demographic data and radiological parameters were analyzed descriptively. Pearson correlation analysis and partial correlation analysis of the parameters were performed. A p-value of less than 0.05 was considered statistically significant. Results The proportion of patients with ≥ 5° of sacral slanting among those with < 3° of pelvic obliquity was 8.9% (27/303). Thirty-two patients (10.6%, 32/303) showed more than 10 mm of LLD. Sacral slanting was positively correlated with pelvic obliquity and lumbar curve (r = 0.445 and r = 0.325, respectively). Pelvic obliquity was also correlated with LLD and L4 tilt (r = 0.123 and r = 0.311, respectively). However, partial correlation analysis showed that LLD was not directly correlated with sacral slanting (r = −0.034). Conclusions Sacral slanting can be thought to be a compensatory mechanism for large lumbar curves, which is accompanied by pelvic obliquity. In contrast, a congenitally slanted upper sacrum may contribute to scoliosis in some cases. LLD was not directly correlated with sacral slanting. PMID:28261428

  2. 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.

  3. 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 (λ 1) 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 λ 1 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

  4. 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

  5. Gleaning Structure from Sound: The Role of Prosodic Contrast in Learning Non-Adjacent Dependencies

    ERIC Educational Resources Information Center

    Grama, Ileana C.; Kerkhoff, Annemarie; Wijnen, Frank

    2016-01-01

    The ability to detect non-adjacent dependencies (i.e. between "a" and "b" in "aXb") in spoken input may support the acquisition of morpho-syntactic dependencies (e.g. "The princess 'is' kiss'ing' the frog"). Functional morphemes in morpho-syntactic dependencies are often marked by perceptual cues that render…

  6. Fish assemblage structure in the hypoxic zone in the Changjiang (Yangtze River) estuary and its adjacent waters

    NASA Astrophysics Data System (ADS)

    Shan, Xiujuan; Jin, Xianshi; Yuan, Wei

    2010-05-01

    Fish assemblage structure in the hypoxic zone in the Changjiang (Yangtze River) estuary and its adjacent waters were analyzed based on data from bottom trawl surveys conducted on the R/V Beidou in June, August and October 2006. Four fish assemblages were identified in each survey using two-way indicator species analysis (TWIA). High fish biomass was found in the northern part, central part and coastal waters of the survey area; in contrast, high fish diversity was found in the southern part of the survey area and the Changjiang estuary outer waters. Therefore, it is difficult to maintain high fishery production when high fish diversity is evenly distributed in the fish community. Fish became smaller and fish size spectra tended to be narrower because of fish species variations and differences in growth characteristics. Fish diversity increased, the age to maturity was reduced and some migrant species were not collected in the surveys. Fish with low economic value, small size, simple age structure and low tropic level were predominant in fish assemblages in the Changjiang estuary and its adjacent waters. The lowest hypoxic value decreased in the Changjiang estuary and its adjacent waters.

  7. 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.

  8. 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.

  9. 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

  10. New data on tectonics of Mendeleev Ridge and adjacent geological structures

    NASA Astrophysics Data System (ADS)

    Chernykh, A. A.; Astafurova, E. G.; Glebovsky, V. Yu.; Korneva, M. S.; Egorova, A. V.; Red'ko, A. G.

    2016-09-01

    The comprehensive analysis of potential field data and recent seismic data revealed two systems of fractures bounding horsts and grabens in terms of the Mendeleev Ridge. The northern part of the ridge is marked by development of pull-apart structures indicating the former existence of oblique extension settings. The area between Mendeleev and Alpha ridges is occupied by a wide NW‒SE-extending sinistral strike-slip zone. It is concluded that these ridges are of continental origin representing former parts of Arctida (Hyperborea) in the pre-Cretaceous time. The ridges were separated and their crust significantly altered during Cretaceous tectono-magmatic activation in the region.

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

    PubMed Central

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

    2016-01-01

    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

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

    USGS Publications Warehouse

    Perry, W.J.; 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

  13. Irreversible Electroporation in the Epidural Space of the Porcine Spine: Effects on Adjacent Structures.

    PubMed

    Tam, Alda L; Figueira, Tomas A; Gagea, Mihai; Ensor, Joe E; Dixon, Katherine; McWatters, Amanda; Gupta, Sanjay; Fuentes, David T

    2016-12-01

    Purpose To determine the effects of irreversible electroporation (IRE) on the neural tissues after ablation in the epidural space of the porcine spine. Materials and Methods The institutional animal care and use committee approved this study. With the IRE electrode positioned in the right lateral recess of the spinal epidural space, 20 IRE ablations were performed with computed tomographic (CT) guidance by using different applied voltages in four animals that were euthanized immediately after magnetic resonance (MR) imaging of the spine, performed 6 hours after IRE (terminal group). Histopathologic characteristics of the neural tissues were assessed and used to select a voltage for a survival study. Sixteen CT-guided IRE ablations in the epidural space were performed by using 667 V in four animals that were survived for 7 days (survival group). Clinical characteristics, MR imaging findings (obtained 6 hours after IRE and before euthanasia), histopathologic characteristics, and simulated electric field strengths were assessed. A one-way analysis of variance was used to compare the simulated electric field strength to histologic findings. Results The mean distance between the IRE electrode and the spinal cord and nerve root was 1.71 mm ± 0.90 and 8.47 mm + 3.44, respectively. There was no clinical evidence of paraplegia after IRE ablation. MR imaging and histopathologic examination showed no neural tissue lesions within the spinal cord; however, five of 16 nerve roots (31.2%) demonstrated moderate wallerian degeneration in the survival group. The severity of histopathologic injury in the survival group was not significantly related to either the simulated electric field strength or the distance between the IRE electrode and the neural structure (P > .05). Conclusion Although the spinal cord appears resistant to the toxic effects of IRE, injury to the nerve roots may be a limiting factor for the use of IRE ablation in the epidural space. (©) RSNA, 2016 Online

  14. 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.

  15. Determining Crustal Structure beneath the New Madrid Seismic Zone and Adjacent Areas: Application of a Reverberation-removal Filter

    NASA Astrophysics Data System (ADS)

    Liu, L.; Gao, S. S.; Liu, K. H.

    2015-12-01

    The New Madrid Seismic Zone (NMSZ) and some of the adjacent areas are covered by a low-velocity sedimentary sequence, giving rise to strong reverberations in the P-to-S receiver functions (RFs) and making it difficult to reliably determine crustal thickness and Poisson's ratio using the conventional H-k stacking technique. Here we apply a newly developed technique (Yu et al., 2015; doi: 10.1002/2014JB011610) to effectively remove or reduce the reverberations from the sedimentary layer to obtain more reliable results. Stacking of a total of 38528 radial RFs recorded by 343 stations in the study area shows systematic spatial variations in crustal thickness (H), Vp/Vs ratio and amplitude (R; relative to the direction P) of the converted Moho phases. Our results indicate that the upper Mississippi Embayment (ME), a broad southwest-plunging trough with the thickest sedimentary layer in the study area, is characterized by a thin crustal thickness (~32 km), while adjacent areas have relatively thicker crust (>40 km). This area also possesses relatively large Vp/Vs (>1.85) values, suggesting possible intrusion of mantle-derived mafic rocks. Most part of the Ozark Uplift is characterized by relatively small Vp/Vs (<1.79) values which indicate an overall felsic crust. In contrast to the NMSZ which is part of the Reelfoot rift, the southern Illinois Basin, which is an intracontinental sag basin, is characterized by a crust of about 45 km which is a few km thicker than the surrounding areas, and a normal Vp/Vs, suggesting sharp differences in crustal structure between rift and sag basins.

  16. 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.

  17. Trace metal mobility and microbial community structure in tropical soils: examples from adjacent forest and grassland ecosystems

    NASA Astrophysics Data System (ADS)

    Wilson, A. D.; Roberts, J. A.; MacPherson, G. L.; Mauck, B. S.; Stallard, R. F.

    2004-12-01

    Many factors determine the quality and sustainability of a soil environment and changes in land use can impact significantly soil geochemistry and the associated soil microbial communities. Native tropical forests and human-constructed grasslands on Barro Colorado Island provide an excellent setting for comparing changes in soil ecosystems in undisturbed and altered landscapes. The goals of this study were to examine biological, chemical, and mineralogical changes in soil properties as a function of land use changes during the wet and dry seasons. Soil pits were excavated at two study sites, a tropical forest and an adjacent plot that has been converted to grassland, during March 2002 and August 2003. The 1 meter deep pits were sampled at 5 cm intervals and characterized for soil organic matter content, soil moisture, community structure and total lipid biomass of the soil microbial community, mineralogy, and trace metal distribution using a sequential extraction method. Results demonstrate that forested soils exhibit higher organic matter content than grassland soils regardless of soil moisture content. Total lipid biomass of the active soil microbial population decreases with depth in both soils, but is elevated in the forested soil, likely correlating with the organic matter content in this system. Diversity of the soil microbial community, determined by PLFA analysis, decreases sharply at the base of the root zone and general trends in community structure are similar in both soils. XRD analysis of the soils reveal that the weathering profile in the forest has extended to a greater depth, but these differences in the mineralogy profile do not exert significant control on trace element mobility. Vanadium, copper, zinc, and aluminum show strong affinities for the organically bound fraction in both soils.

  18. Food structure is critical for optimal health.

    PubMed

    Wahlqvist, Mark L

    2016-03-01

    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".

  19. [Effects of macro-jellyfish abundance dynamics on fishery resource structure in the Yangtze River estuary and its adjacent waters].

    PubMed

    Shan, Xiu-Juan; Zhuang, Zhi-Meng; Jin, Xian-Shi; Dai, Fang-Qun

    2011-12-01

    Based on the bottom trawl survey data in May 2007 and May and June 2008, this paper analyzed the effects of the abundance dynamics of macro-jellyfish on the species composition, distribution, and abundance of fishery resource in the Yangtze River estuary and its adjacent waters. From May 2007 to June 2008, the average catch per haul and the top catch per haul of macro-jellyfish increased, up to 222.2 kg x h(-1) and 1800 kg x h(-1) in June 2008, respectively. The macro-jellyfish were mainly distributed in the areas around 50 m isobath, and not beyond 100 m isobath where was the joint front of the coastal waters of East China Sea, Yangtze River runoff, and Taiwan Warm Current. The main distribution area of macro-jellyfish in June migrated northward, as compared with that in May, and the highest catches of macro-jellyfish in May 2007 and May 2008 were found in the same sampling station (122.5 degrees E, 28.5 degrees N). In the sampling stations with higher abundance of macro-jellyfish, the fishery abundance was low, and the fishery species also changed greatly, mainly composed by small-sized species (Trachurus japonicus, Harpadon nehereus, and Acropoma japonicum) and pelagic species (Psenopsis anomala, Octopus variabilis) and Trichiurus japonicus, and P. anomala accounted for 23.7% of the total catch in June 2008. Larimichthys polyactis also occupied higher proportion of the total catch in sampling stations with higher macro-jellyfish abundance, but the demersal species Lophius litulon was not found, and a few crustaceans were collected. This study showed that macro-jellyfish had definite negative effects on the fishery community structure and abundance in the Yangtze River estuary fishery ecosystem, and further, changed the energy flow patterns of the ecosystem through cascading trophic interactions. Therefore, macro-jellyfish was strongly suggested to be an independent ecological group when the corresponding fishery management measures were considered.

  20. 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.

  1. Critical Scales, Fundamental Structures and Inherent Instabilities of Turbulent Flames

    DTIC Science & Technology

    2015-06-01

    AFRL-OSR-VA-TR-2015-0182 Critical Scales , Fundamental Structures and... of Turbulent Flames Forman Williams UNIVERSITY OF CALIFORNIA SAN DIEGO Final...SUBTITLE Critical Scales , Fundamental Structures and Inherent Instabilities of Turbulent Flames 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-12-1...turbulence scales were both analyzed. It was shown that in both limits interactions of detonations with non-uniform fluid density fields had greater

  2. Photosynthesis irradiance parameters and community structure associated with coastal filaments and adjacent waters in the northern Arabian Sea

    NASA Astrophysics Data System (ADS)

    Toon, Rory K.; Lohrenz, Steven E.; Rathbun, Catherine E.; Michelle Wood, A.; Arnone, Robert A.; Jones, Burton H.; Kindle, John C.; Weidemann, Alan D.

    Comparisons were made among size-fractionated photosynthesis-irradiance ( P- E) parameters, chlorophyll a size distributions, and accessory pigment composition of natural phytoplankton assemblages in filaments, coastal upwelling waters, and an oligotrophic region of the northern Arabian Sea during the Fall Intermonsoon in 1995. Differences between P- E parameters, PBmax and αB, were observed between filaments and adjacent waters and were associated with differences in phytoplankton community structure. In a southern filament and coastal upwelled waters, the majority of the estimated biomass (chlorophyll a) was present in the larger (2-20 and 20-200 μm) size fractions; dominant accessory pigments were 19'-butanoyloxyfucoxanthin and peridinin. In higher salinity waters, high percentages of chlorophyll a and lutein/zeaxanthin were observed in the smallest size-fraction (<2 μm). Whole water values of PBmax ranged from 1.77 to 2.31 (g C g chl a-1 h -1) when the majority of the biomass was in the largest fractions. Higher values (more than 4.48 g C g chl a-1 h -1) were determined in whole water samples for communities comprised primarily of small cells. A size dependence was also observed in the value of αB, 0.017 or greater (g C g chl a-1 h -1)/(μmol quanta m -2 s -1) for whole water samples at stations dominated by small cells and 0.013 when derived from stations dominated by large cells. The observed pattern of larger phytoplankton associated with upwelling and filament waters was consistent with previous investigations and was, for the most part, comparable to findings in the California Current system. Our results show that differences in taxonomic composition and photosynthetic characteristics were indeed present between filament waters and other distinct regions; these results suggest that taxonomic variations may be associated with size-related variations in P- E parameters. Our findings provide a unique data set describing filament biology in the northern

  3. An analytical solution for the consideration of the effect of adjacent fuel assemblies; comparison of rectangular and hexagonal structures

    SciTech Connect

    Merk, B.; Rohde, U.

    2012-07-01

    A new analytical method is described to deal with the Leakage Environmental Effect. The method is based on the analytical solution of the two-group diffusion equation for two adjacent fuel assemblies. The quality of the results for this highly efficient method is demonstrated for square fuel assemblies. In additional tests the transferability of the concept to hexagonal VVER-440-type fuel assemblies is shown and a comparison between the results for rectangular and hexagonal assemblies is given. (authors)

  4. A theoretical study of the local electronic structure of two adjacent CuOplanes in YBa 2Cu 3O 7

    NASA Astrophysics Data System (ADS)

    Suter, H. U.; Stoll, E. P.; Hüsser, P.; Schafroth, S.; Meier, P. F.

    1997-08-01

    To reveal the local electronic structure of the two adjacent CuOplanes in YBa 2Cu 3O 7, ab initio studies on a small cluster (Cu 2Y 4O 8) were performed. Electron correlation was investigated with both density functional theory and Møller-Plesset theory. The ionisation energies, electron affinities adn the singlet-triplet differences are discussed with respect to model Hamiltonians of high-T c compounds.

  5. 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.

  6. 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.

  7. 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.

  8. Adjacent positioning of cellular structures enabled by a Cdc42 GTPase-activating protein-mediated zone of inhibition.

    PubMed

    Tong, Zongtian; Gao, Xiang-Dong; Howell, Audrey S; Bose, Indrani; Lew, Daniel J; Bi, Erfei

    2007-12-31

    Cells of the budding yeast Saccharomyces cerevisiae are born carrying localized transmembrane landmark proteins that guide the subsequent establishment of a polarity axis and hence polarized growth to form a bud in the next cell cycle. In haploid cells, the relevant landmark proteins are concentrated at the site of the preceding cell division, to which they recruit Cdc24, the guanine nucleotide exchange factor for the conserved polarity regulator Cdc42. However, instead of polarizing at the division site, the new polarity axis is directed next to but not overlapping that site. Here, we show that the Cdc42 guanosine triphosphatase-activating protein (GAP) Rga1 establishes an exclusion zone at the division site that blocks subsequent polarization within that site. In the absence of localized Rga1 GAP activity, new buds do in fact form within the old division site. Thus, Cdc42 activators and GAPs establish concentric zones of action such that polarization is directed to occur adjacent to but not within the previous cell division site.

  9. Field Structure of a Quasisoliton Approaching the Critical Point

    NASA Astrophysics Data System (ADS)

    Gorshkov, K. A.; Soustova, I. A.; Ermoshkin, A. V.

    2016-03-01

    Within the framework of an approximate approach based on the representation of the Gardnerequation solitons as compound structures (different-polarity kinks), the non-quasistationary evolution of such solitary waves, which is stipulated by the variable quadratic-nonlinearity parameter α. The structure of the composite soliton is studied in cases that are critical for the quasistationary description where the predicted increase in the solitary-wave scales becomes unbounded on finite spatio-temporal intervals. The dependence of the spatial scales of the quasisoliton-field distribution on the quadratic-nonlinearity coefficient near the critical point for the power-law time dependence α(t) is studied in detail. The obtained solution is compared with the results of direct numerical simulation of the Gardner equation with variable coefficients.

  10. Correlative anatomy for the electrophysiologist: ablation for atrial fibrillation. Part II: regional anatomy of the atria and relevance to damage of adjacent structures during AF ablation.

    PubMed

    Macedo, Paula G; Kapa, Suraj; Mears, Jennifer A; Fratianni, Amy; Asirvatham, Samuel J

    2010-07-01

    Ablation procedures for atrial fibrillation have become an established and increasingly used option for managing patients with symptomatic arrhythmia. The anatomic structures relevant to the pathogenesis of atrial fibrillation and ablation procedures are varied and include the pulmonary veins, other thoracic veins, the left atrial myocardium, and autonomic ganglia. Exact regional anatomic knowledge of these structures is essential to allow correlation with fluoroscopy and electrograms and, importantly, to avoid complications from damage of adjacent structures within the chest. We present this information as a series of 2 articles. In a prior issue, we have discussed the thoracic vein anatomy relevant to paroxysmal atrial fibrillation. In the present article, we focus on the atria themselves, the autonomic ganglia, and anatomic issues relevant for minimizing complications during atrial fibrillation ablation.

  11. Critical currents in A-15 structure Nb3Al converted from cold-worked bcc structure

    NASA Technical Reports Server (NTRS)

    Woollam, J. A.; Alterovitz, S. A.; Haugland, E.; Webb, G. W.

    1980-01-01

    The paper considers critical currents in A-15 structure Nb3Al converted from a cold-worked bcc structure. Nb3Al prepared in the ductile phase by quenching and mechanical working followed by conversion to the A-15 structure could carry currents above 10 to the 9th power A/sq m in fields near 20 T. These critical currents are comparable to those of Nb3Ge and V3Ga which are closest competing materials for use in high fields; further enhancement of the critical current is possible if thermal treatments are optimized.

  12. The structure of the human tRNALys3 anticodon bound to the HIV genome is stabilized by modified nucleosides and adjacent mismatch base pairs.

    PubMed

    Bilbille, Yann; Vendeix, Franck A P; Guenther, Richard; Malkiewicz, Andrzej; Ariza, Xavier; Vilarrasa, Jaume; Agris, Paul F

    2009-06-01

    Replication of human immunodeficiency virus (HIV) requires base pairing of the reverse transcriptase primer, human tRNA(Lys3), to the viral RNA. Although the major complementary base pairing occurs between the HIV primer binding sequence (PBS) and the tRNA's 3'-terminus, an important discriminatory, secondary contact occurs between the viral A-rich Loop I, 5'-adjacent to the PBS, and the modified, U-rich anticodon domain of tRNA(Lys3). The importance of individual and combined anticodon modifications to the tRNA/HIV-1 Loop I RNA's interaction was determined. The thermal stabilities of variously modified tRNA anticodon region sequences bound to the Loop I of viral sub(sero)types G and B were analyzed and the structure of one duplex containing two modified nucleosides was determined using NMR spectroscopy and restrained molecular dynamics. The modifications 2-thiouridine, s(2)U(34), and pseudouridine, Psi(39), appreciably stabilized the interaction of the anticodon region with the viral subtype G and B RNAs. The structure of the duplex results in two coaxially stacked A-form RNA stems separated by two mismatched base pairs, U(162)*Psi(39) and G(163)*A(38), that maintained a reasonable A-form helix diameter. The tRNA's s(2)U(34) stabilized the interaction between the A-rich HIV Loop I sequence and the U-rich anticodon, whereas the tRNA's Psi(39) stabilized the adjacent mismatched pairs.

  13. Critical Features of Fragment Libraries for Protein Structure Prediction.

    PubMed

    Trevizani, Raphael; Custódio, Fábio Lima; Dos Santos, Karina Baptista; Dardenne, Laurent Emmanuel

    2017-01-01

    The use of fragment libraries is a popular approach among protein structure prediction methods and has proven to substantially improve the quality of predicted structures. However, some vital aspects of a fragment library that influence the accuracy of modeling a native structure remain to be determined. This study investigates some of these features. Particularly, we analyze the effect of using secondary structure prediction guiding fragments selection, different fragments sizes and the effect of structural clustering of fragments within libraries. To have a clearer view of how these factors affect protein structure prediction, we isolated the process of model building by fragment assembly from some common limitations associated with prediction methods, e.g., imprecise energy functions and optimization algorithms, by employing an exact structure-based objective function under a greedy algorithm. Our results indicate that shorter fragments reproduce the native structure more accurately than the longer. Libraries composed of multiple fragment lengths generate even better structures, where longer fragments show to be more useful at the beginning of the simulations. The use of many different fragment sizes shows little improvement when compared to predictions carried out with libraries that comprise only three different fragment sizes. Models obtained from libraries built using only sequence similarity are, on average, better than those built with a secondary structure prediction bias. However, we found that the use of secondary structure prediction allows greater reduction of the search space, which is invaluable for prediction methods. The results of this study can be critical guidelines for the use of fragment libraries in protein structure prediction.

  14. Critical Features of Fragment Libraries for Protein Structure Prediction

    PubMed Central

    dos Santos, Karina Baptista

    2017-01-01

    The use of fragment libraries is a popular approach among protein structure prediction methods and has proven to substantially improve the quality of predicted structures. However, some vital aspects of a fragment library that influence the accuracy of modeling a native structure remain to be determined. This study investigates some of these features. Particularly, we analyze the effect of using secondary structure prediction guiding fragments selection, different fragments sizes and the effect of structural clustering of fragments within libraries. To have a clearer view of how these factors affect protein structure prediction, we isolated the process of model building by fragment assembly from some common limitations associated with prediction methods, e.g., imprecise energy functions and optimization algorithms, by employing an exact structure-based objective function under a greedy algorithm. Our results indicate that shorter fragments reproduce the native structure more accurately than the longer. Libraries composed of multiple fragment lengths generate even better structures, where longer fragments show to be more useful at the beginning of the simulations. The use of many different fragment sizes shows little improvement when compared to predictions carried out with libraries that comprise only three different fragment sizes. Models obtained from libraries built using only sequence similarity are, on average, better than those built with a secondary structure prediction bias. However, we found that the use of secondary structure prediction allows greater reduction of the search space, which is invaluable for prediction methods. The results of this study can be critical guidelines for the use of fragment libraries in protein structure prediction. PMID:28085928

  15. Structure and tectonic evolution of the Tornquist Zone and adjacent sedimentary basins in Scania and the southern Baltic Sea area

    NASA Astrophysics Data System (ADS)

    Erlström, M.; Thomas, S. A.; Deeks, N.; Sivhed, U.

    1997-04-01

    Southernmost Sweden, Bornholm and the surrounding Baltic Sea region are located on a large-scale releasing bend in the dextral strike-slip system of the Tornquist Zone, with its resulting pull-apart basins. The well constrained geology of Scania and Bornholm has been combined with detailed on- and offshore borehole data and three proprietary marine seismic surveys. This in conjunction with supplementary BABEL deep seismic reflection findings allows a combined 3D interpretation of sediment/structure interactions. As a result, a regional interpretation has emerged which gives a new understanding of the interplay between structural movement on a complex strike-slip fault system (Tornquist Zone) and its intrazonal depressions (Vomb Trough and Colonus Shale Trough) as well as the sedimentation history of associated areas of sediment accumulation (Rønne and Arnager Grabens, Höllviken Halfgraben, Hanö Bay Basin and Skurup Platform). Detailed sequential litho- and seismo-stratigraphic descriptions have been possible by combination of the various data sets. This resulted in the clarification or recognition of previously unknown structural limits to sub-basins and highs in the study area. A 3D chronological (4D) model for the development of the region is proposed. This model takes into account the long-lived structural history combining elements of strike-slip, extension and inversion tectonics. The deep-seated faulting controlling these structures is integrated with the deep structure as revealed by the BABEL line in this area.

  16. 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…

  17. 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

  18. Genetic Structure and Evolutionary History of Three Alpine Sclerophyllous Oaks in East Himalaya-Hengduan Mountains and Adjacent Regions

    PubMed Central

    Feng, Li; Zheng, Qi-Jian; Qian, Zeng-Qiang; Yang, Jia; Zhang, Yan-Ping; Li, Zhong-Hu; Zhao, Gui-Fang

    2016-01-01

    The East Himalaya-Hengduan Mountains (EH-HM) region has a high biodiversity and harbors numerous endemic alpine plants. This is probably the result of combined orographic and climate oscillations occurring since late Tertiary. Here, we determined the genetic structure and evolutionary history of alpine oak species (including Quercus spinosa, Quercus aquifolioides, and Quercus rehderiana) using both cytoplasmic-nuclear markers and ecological niche models (ENMs), and elucidated the impacts of climate oscillations and environmental heterogeneity on their population demography. Our results indicate there were mixed genetic structure and asymmetric contemporary gene flow within them. The ENMs revealed a similar demographic history for the three species expanded their ranges from the last interglacial (LIG) to the last glacial maximum (LGM), which was consistent with effective population sizes changes. Effects of genetic drift and fragmentation of habitats were responsible for the high differentiation and the lack of phylogeographic structure. Our results support that geological and climatic factors since Miocene triggered the differentiation, evolutionary origin and range shifts of the three oak species in the studied area and also emphasize that a multidisciplinary approach combining molecular markers, ENMs and population genetics can yield deep insights into diversification and evolutionary dynamics of species. PMID:27891142

  19. Genetic Structure and Evolutionary History of Three Alpine Sclerophyllous Oaks in East Himalaya-Hengduan Mountains and Adjacent Regions.

    PubMed

    Feng, Li; Zheng, Qi-Jian; Qian, Zeng-Qiang; Yang, Jia; Zhang, Yan-Ping; Li, Zhong-Hu; Zhao, Gui-Fang

    2016-01-01

    The East Himalaya-Hengduan Mountains (EH-HM) region has a high biodiversity and harbors numerous endemic alpine plants. This is probably the result of combined orographic and climate oscillations occurring since late Tertiary. Here, we determined the genetic structure and evolutionary history of alpine oak species (including Quercus spinosa, Quercus aquifolioides, and Quercus rehderiana) using both cytoplasmic-nuclear markers and ecological niche models (ENMs), and elucidated the impacts of climate oscillations and environmental heterogeneity on their population demography. Our results indicate there were mixed genetic structure and asymmetric contemporary gene flow within them. The ENMs revealed a similar demographic history for the three species expanded their ranges from the last interglacial (LIG) to the last glacial maximum (LGM), which was consistent with effective population sizes changes. Effects of genetic drift and fragmentation of habitats were responsible for the high differentiation and the lack of phylogeographic structure. Our results support that geological and climatic factors since Miocene triggered the differentiation, evolutionary origin and range shifts of the three oak species in the studied area and also emphasize that a multidisciplinary approach combining molecular markers, ENMs and population genetics can yield deep insights into diversification and evolutionary dynamics of species.

  20. The effects of timber harvesting on the structure and composition of adjacent old-growth coast redwood forest, California, USA

    USGS Publications Warehouse

    Russell, W.H.; Jones, C.

    2001-01-01

    Data collected across timber harvest boundaries on nine sites within the Redwood National and State Park management area in California, USA, were used to estimate the effective size of old-growth coast redwood preserves. Fourteen variables related to stand structure and composition, wildlife habitat, and physical environment were significantly correlated to distance from the timber harvest boundary using multiple regression analysis. A maximum depth of edge influence of 200 m was determined for variables exhibiting a significant correlation to the distance from the harvest edge. A spatial analysis using ArcView indicated that 53% of the old growth preserved within the study area was influenced by edge conditions, leaving 47% as effective old-growth.

  1. Crustal structure beneath Liaoning province and the Bohai Sea and its adjacent region in China based on ambient noise tomography

    NASA Astrophysics Data System (ADS)

    Pang, Guang-hua; Feng, Ji-Kun; Lin, Jun

    2017-03-01

    The velocity structure of the crust beneath Liaoning province and the Bohai sea in China was imaged using ambient seismic noise recorded by 73 regional broadband stations. All available three-component time series from the 12-month span between January and December 2013 were cross-correlated to yield empirical Green's functions for Rayleigh and Love waves. Phase-velocity dispersion curves for the Rayleigh waves and the Love waves were measured by applying the frequency-time analysis method. Dispersion measurements of the Rayleigh wave and the Love wave were then utilized to construct 2D phase-velocity maps for the Rayleigh wave at 8-35 s periods and the Love wave at 9-32 s periods, respectively. Both Rayleigh and Love phase-velocity maps show significant lateral variations that are correlated well with known geological features and tectonics units in the study region. Next, phase dispersion curves of the Rayleigh wave and the Love wave extracted from each cell of the 2D Rayleigh wave and Love wave phase-velocity maps, respectively, were inverted simultaneously to determine the 3D shear wave velocity structures. The horizontal shear wave velocity images clearly and intuitively exhibit that the earthquake swarms in the Haicheng region and the Tangshan region are mainly clustered in the transition zone between the low- and high-velocity zones in the upper crust, coinciding with fault zones, and their distribution is very closely associated with these faults. The vertical shear wave velocity image reveals that the lower crust downward to the uppermost mantle is featured by distinctly high velocities, with even a high-velocity thinner layer existing at the bottom of the lower crust near Moho in central and northern the Bohai sea along the Tanlu fault, and these phenomena could be caused by the intrusion of mantle material, indicating the Tanlu fault could be just as the uprising channel of deep materials.

  2. 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

  3. 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.

  4. Functional Morphology of the Arm Spine Joint and Adjacent Structures of the Brittlestar Ophiocomina nigra (Echinodermata: Ophiuroidea).

    PubMed

    Wilkie, Iain C

    2016-01-01

    The skeletal morphology of the arm spine joint of the brittlestar Ophiocomina nigra was examined by scanning electron microscopy and the associated epidermis, connective tissue structures, juxtaligamental system and muscle by optical and transmission electron microscopy. The behaviour of spines in living animals was observed and two experiments were conducted to establish if the spine ligament is mutable collagenous tissue: these determined (1) if animals could detach spines to which plastic tags had been attached and (2) if the extension under constant load of isolated joint preparations was affected by high potassium stimulation. The articulation normally operates as a flexible joint in which the articular surfaces are separated by compliant connective tissue. The articular surfaces comprise a reniform apposition and peg-in-socket mechanical stop, and function primarily to stabilise spines in the erect position. Erect spines can be completely immobilised, which depends on the ligament having mutable tensile properties, as was inferred from the ability of animals to detach tagged spines and the responsiveness of isolated joint preparations to high potassium. The epidermis surrounding the joint has circumferential constrictions that facilitate compression folding and unfolding when the spine is inclined. The interarticular connective tissue is an acellular meshwork of collagen fibril bundles and may serve to reduce frictional forces between the articular surfaces. The ligament consists of parallel bundles of collagen fibrils and 7-14 nm microfibrils. Its passive elastic recoil contributes to the re-erection of inclined spines. The ligament is permeated by cell processes containing large dense-core vesicles, which belong to two types of juxtaligamental cells, one of which is probably peptidergic. The spine muscle consists of obliquely striated myocytes that are linked to the skeleton by extensions of their basement membranes. Muscle contraction may serve mainly to

  5. Functional Morphology of the Arm Spine Joint and Adjacent Structures of the Brittlestar Ophiocomina nigra (Echinodermata: Ophiuroidea)

    PubMed Central

    Wilkie, Iain C.

    2016-01-01

    The skeletal morphology of the arm spine joint of the brittlestar Ophiocomina nigra was examined by scanning electron microscopy and the associated epidermis, connective tissue structures, juxtaligamental system and muscle by optical and transmission electron microscopy. The behaviour of spines in living animals was observed and two experiments were conducted to establish if the spine ligament is mutable collagenous tissue: these determined (1) if animals could detach spines to which plastic tags had been attached and (2) if the extension under constant load of isolated joint preparations was affected by high potassium stimulation. The articulation normally operates as a flexible joint in which the articular surfaces are separated by compliant connective tissue. The articular surfaces comprise a reniform apposition and peg-in-socket mechanical stop, and function primarily to stabilise spines in the erect position. Erect spines can be completely immobilised, which depends on the ligament having mutable tensile properties, as was inferred from the ability of animals to detach tagged spines and the responsiveness of isolated joint preparations to high potassium. The epidermis surrounding the joint has circumferential constrictions that facilitate compression folding and unfolding when the spine is inclined. The interarticular connective tissue is an acellular meshwork of collagen fibril bundles and may serve to reduce frictional forces between the articular surfaces. The ligament consists of parallel bundles of collagen fibrils and 7–14 nm microfibrils. Its passive elastic recoil contributes to the re-erection of inclined spines. The ligament is permeated by cell processes containing large dense-core vesicles, which belong to two types of juxtaligamental cells, one of which is probably peptidergic. The spine muscle consists of obliquely striated myocytes that are linked to the skeleton by extensions of their basement membranes. Muscle contraction may serve mainly to

  6. Seismicity and S-wave velocity structure of the crust and the upper mantle in the Baikal rift and adjacent regions

    NASA Astrophysics Data System (ADS)

    Seredkina, Alena; Kozhevnikov, Vladimir; Melnikova, Valentina; Solovey, Oksana

    2016-12-01

    Correlations between seismicity, seismotectonic deformation (STD) field and velocity structure of the crust and the upper mantle in the Baikal rift and the adjacent areas of the Siberian platform and the Mongol-Okhotsk fold belt have been investigated. The 3D S-wave velocity structure up to the depths of 500 km has been modeled using a representative sample of Rayleigh wave group velocity dispersion curves (about 3200 paths) at periods from 10 to 250 s. The STD pattern has been reconstructed from mechanisms of large earthquakes, and is in good agreement with GPS and structural data. Analysis of the results has shown that most of large shallow earthquakes fall in regions of low S-wave velocities in the uppermost mantle (western Mongolia and areas of recent mountain building in southern Siberia) and in zones of their relatively high lateral variations (northeastern flank of the Baikal rift). In the first case the dominant STD regime is compression manifested in a mixture of thrust and strike-slip deformations. In the second case we observe a general predominance of extension.

  7. 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.

  8. Detection of Critical Camera Configurations for Structure from Motion

    NASA Astrophysics Data System (ADS)

    Michelini, M.; Mayer, H.

    2014-03-01

    This paper deals with the detection of critical, i.e., poor or degenerate camera configurations, with a poor or undefined intersection geometry between views. This is the basis for a calibrated Structure from Motion (SfM) approach employing image triplets for complex, unordered image sets, e.g., obtained by combining terrestrial images and images from small Unmanned Aerial Systems (UAS). Poor intersection geometry results from a small ratio between the baseline length and the depth of the scene. If there is no baseline between views, the intersection geometry becomes undefined. Our approach can detect image pairs without or with a very weak baseline (motion degeneracy). For the detection we have developed various metrics and evaluated them by means of extensive experiments with about 1500 image pairs. The metrics are based on properties of the reconstructed 3D points, such as the roundness of the error ellipsoid. The detection of weak baselines is formulated as a classification problem using the metrics as features. Machine learning techniques are applied to improve the classification. By taking into account the critical camera configurations during the iterative composition of the image set, a complete, metric 3D reconstruction of the whole scene could be achieved also in this case. We sketch our approach for the orientation of unordered image sets and finally demonstrate that the approach is able to produce very accurate and reliable orientations.

  9. 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

  10. 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

  11. A Poroelastic Fluid/Structure-Interaction Model of Cerebrospinal Fluid Dynamics in the Cord With Syringomyelia and Adjacent Subarachnoid-Space Stenosis.

    PubMed

    Bertram, C D; Heil, M

    2017-01-01

    An existing axisymmetric fluid/structure-interaction (FSI) model of the spinal cord, pia mater, subarachnoid space, and dura mater in the presence of syringomyelia and subarachnoid-space stenosis was modified to include porous solids. This allowed investigation of a hypothesis for syrinx fluid ingress from cerebrospinal fluid (CSF). Gross model deformation was unchanged by the addition of porosity, but pressure oscillated more in the syrinx and the subarachnoid space below the stenosis. The poroelastic model still exhibited elevated mean pressure in the subarachnoid space below the stenosis and in the syrinx. With realistic cord permeability, there was slight oscillatory shunt flow bypassing the stenosis via the porous tissue over the syrinx. Weak steady streaming flow occurred in a circuit involving craniocaudal flow through the stenosis and back via the syrinx. Mean syrinx volume was scarcely altered when the adjacent stenosis bisected the syrinx, but increased slightly when the syrinx was predominantly located caudal to the stenosis. The fluid content of the tissues over the syrinx oscillated, absorbing most of the radial flow seeping from the subarachnoid space so that it did not reach the syrinx. To a lesser extent, this cyclic swelling in a boundary layer of cord tissue just below the pia occurred all along the cord, representing a mechanism for exchange of interstitial fluid (ISF) and cerebrospinal fluid which could explain recent tracer findings without invoking perivascular conduits. The model demonstrates that syrinx volume increase is possible when there is subarachnoid-space stenosis and the cord and pia are permeable.

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

    PubMed Central

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

    2013-01-01

    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

  13. Determination of microbial biomass and its community structure from the distribution of phospholipid ester-linked fatty acids in sediments of Hiroshima Bay and its adjacent bays

    NASA Astrophysics Data System (ADS)

    Rajendran, N.; Matsuda, O.; Imamura, N.; Urushigawa, Y.

    1992-05-01

    Phospholipid ester-linked fatty acid (PLFA) composition in sediment samples collected from 20 sampling stations of Hiroshima Bay and its adjacent bays are reported. Thirty-one individual fatty acids were identified in the sediments which comprised of saturated, monounsaturated, polyunsaturated and branched fatty acids. A majority of these fatty acids are characteristic of aerobic and anaerobic bacteria especially sulphate-reducing bacteria. PLFA profiles in the sediments varied among the stations indicating the differences in the contributing microbial communities. The calculated biomass also varied from 0·3 × 10 7 to 2·6 × 10 7 cells g -1 dry weight sediment. The shift in microbial community structure within the study area is understood from the seven clusters obtained by the similarity analysis of PLFA composition. The results of environmental parameters revealed the existence of both oxic and anoxic conditions in the study area and the PLFA composition in sediments is discussed in relation to these environmental parameters. Low concentrations of polyunsaturated fatty acids (PUFA) determined in sediments, characteristic of microeukaryotes, could be attributed to the existing environmental conditions and pollution in the study area. Small quantities of long chain fatty acids in sediments indicated that the terrestrial input is low.

  14. Magnetic structures of the low temperature phase of Mn3(VO4)2 - towards understanding magnetic ordering between adjacent Kagomé layers.

    PubMed

    Clemens, Oliver; Rohrer, Jochen; Nénert, Gwilherm

    2016-01-07

    In this article we report on a detailed analysis of the magnetic structures of the magnetic phases of the low temperature (lt-) phase of Mn3(VO4)2 (=Mn3V2O8) with a Kagomé staircase structure determined by means of powder neutron diffraction. Two magnetic transitions were found at ∼25 K (HT1 phase, Cmc'a') and ∼17 K (LT1 phase, Pmc'a'), in excellent agreement with previous reports. The LT1 phase is characterized by commensurate magnetic ordering of the magnetic moments on two magnetic sites of the Mn1a/b (2a + 2d) and Mn2 (8i) ions of the nuclear structure (where for the latter site two different overall orientations of magnetic moments within the ab-plane (Mn2a and Mn2b) can be distinguished. This results in mainly antiferromagnetic interactions between edge-sharing Mn-octahedra within the Kagomé planes. The HT1 phase is characterised by strong spin frustration resulting from the loss of ordering of the magnetic moments of Mn2a/b ions along the b-axis. Both magnetic structures are in agreement with the previously reported ferrimagnetic properties of lt-Mn3(VO4)2 and shed light on the magnetic phase diagram of the compound reported previously. The magnetic structures are discussed with respect to superexchange interaction pathways within the Kagomé layers, which appear to be predominantly antiferromagnetic. The magnetic structures of Mn3(VO4)2 are different compared to those reported for Ni3(VO4)2 and Co3(VO4)2 and represent an unique commensurate way out of spin frustration for compounds with strong antiferromagnetic superexchange interactions within the Kagomé layers. Additionally, we derive a superexchange model, which will be called redox-mediated M-M(')(d(0))-M superexchange and which can help to understand the exclusively ferromagnetic ordering of adjacent Kagomé layers found only for lt-Mn3(VO4)2.

  15. 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

  16. 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

  17. Tectonic structure of Dokdo and adjacent area in the northeastern part of the Ulleung Basin of the East Sea using geophysical data

    NASA Astrophysics Data System (ADS)

    Kim, C.; Jeong, E.; Park, C.; Kwon, B.; Park, G.; Park, J.

    2008-12-01

    The northeastern part of the Ulleung Basin in the East Sea is composed of volcanic islands (Ulleungdo and Dokdo), seamounts (the Anyongbok Seamount, the Simheungtaek and the Isabu Tablemounts), and a deep pathway (Korea Gap). To understand tectonic structure and geophysical characteristics of Dokdo and adjacent area, We analysed geophysical potential data of KORDI(Korea Ocean Research and Development Institute), KIGAM(Korea Institute of Geoscience and Mineral Resources), and NORI(National Oceanographic Research Institute of Korea) around the Dokdo volcanic body except Ulleung Do because of empty data of its large island. Also, we eliminate the effect of water and sediments from the free-air gravity data to process 3D Moho depth inversion. 3D tectonic structure modelling of the study area was developed using Moho depth inversion result and sediment thickness data of NGDC(National Geophysical Data Center). The free-air gravity anomalies of the study area generally reflect bathymetric effects. Although the Dokdo seamounts have a similar topographic size, the decrease of free-air anomaly toward Isabu suggest that Isabu is oldest among the seaounts and have high degree of isostatic compensation. High Bouguer anomalies in the central part of the Ulleung Basin gradually decreases toward the Oki Bank. This feature suggests that the crust/mantle boundary is shallow in the central part of the Ulleung Basin. The complex magnetic pattern of Dokdo suggests that it might have erupted several times during its formation. The magnetic anomaly amplitude of Isabu is much smaller than that of Dokdo. Such low magnetic anomalies are attributed to a secondary change caused by the metamorphism or weathering of ferromagnetic minerals of the seamount during a long period of time after its formation. Analytic signals show high anomalous zones over volcanoes. Also, there are high analytic signal values in Korea Gap indicating magmatic intrusion in thick sediments. The power spectrum analysis

  18. 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.

  19. Piaget's Structural Developmental Psychology. v. Ideology-Critique and the Possibility of a Critical Developmental Theory.

    ERIC Educational Resources Information Center

    Broughton, John M.

    1981-01-01

    This final essay in a five-part series examining Piaget's structural developmental psychology suggests that a psychological theory which integrates aspects of developmental structuralism within a critical social framework can be developed. (Author/RH)

  20. Method or Madness: Federal Oversight Structures for Critical Infrastructure Protection

    DTIC Science & Technology

    2007-12-01

    51 x THIS PAGE INTENTIONALLY LEFT BLANK xi ACKNOWLEDGMENTS As with most things ...daughters, Amber and Lauren, who always say just the right things to keep this all in perspective. Bike rides and soccer games helped to provide just...critical to the functioning of American society. These infrastructures include things often taken for granted: food and water supplies, banking

  1. 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...

  2. Crust structure of the Northern Margin of North China Craton and adjacent region from Sinoprobe-02 North China seismic WAR/R experiment

    NASA Astrophysics Data System (ADS)

    Li, W.; Gao, R.; Keller, G. R.; Li, Q.; Cox, C. M.; Hou, H.; Guan, Y.

    2011-12-01

    . The records were cut to 60s and reduced by 8 km/s. The initial velocity model began with a subhorizontal multilayer frame, in which the velocity was constructed and modified from adjacent deep seismic sounding sections for the profile, and the structure was constrained by the high-resolution deep seismic reflection stack section alone the same profile. The 2D ray-tracing program RAYINVR was used for forward modeling and inversion of travel times (Zelt, 1992), and VMED was used for creating and modifying velocity models. The travel time modeling was done using the top to bottom approach layer by layer. The velocity model was altered by trial and error, and travel times were calculated many times until the agreement between observed and calculated travel times were acceptable. Subsequently, the forward model was updated by damped least-squares inversion for the velocity and interface nodes. In our modeling, calculated travel times fit observed travel times for all trace with RMS of 0.1-0.2.The final velocity models derived for the profile reveals large variations both in structure and velocity. Supported by Sinoprobe-02 and US NSF PIRE grant (0730154)

  3. 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.

  4. 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

  5. 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.

  6. Structure of critical lines in quenched lattice QCD with the Wilson quark action

    SciTech Connect

    Aoki, S.; Kaneda, T.; Ukawa, A.

    1997-08-01

    The structure of critical lines of a vanishing pion mass for the Wilson quark action is examined in quenched lattice QCD. Numerical evidence is presented that the critical lines spread into five branches beyond {beta}=5.6{endash}5.7 at zero temperature. It is also shown that the critical lines disappear in the deconfined phase for the case of finite temperatures. {copyright} {ital 1997} {ital The American Physical Society}

  7. 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

  8. 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.…

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

    PubMed

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

    2014-05-01

    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.

  10. Structure of a fluid interface near the critical point

    NASA Technical Reports Server (NTRS)

    Schmidt, James W.

    1988-01-01

    The structure of the liquid-liquid interface of three very different mixtures (carbon disulfide + methanol, methanol + cyclohexane + deuterated cyclohexane, and nitrobenzene + n-decane) has been studied using ellipsometry in the reduced temperature range between 0.0009 and 0.042. Although the elliptical thickness varies by an order of magnitude between these mixtures, the data from all three mixtures can be scaled to the same universal constant by a combined mean-field plus capillary-wave model of the interface. The universal constant determined experimentally is significantly less than the theoretical value.

  11. 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.

  12. A critical review of nanotechnologies for composite aerospace structures

    NASA Astrophysics Data System (ADS)

    Kostopoulos, Vassilis; Masouras, Athanasios; Baltopoulos, Athanasios; Vavouliotis, Antonios; Sotiriadis, George; Pambaguian, Laurent

    2017-03-01

    The past decade extensive efforts have been invested in understanding the nano-scale and revealing the capabilities offered by nanotechnology products to structural materials. Integration of nano-particles into fiber composites concludes to multi-scale reinforced composites and has opened a new wide range of multi-functional materials in industry. In this direction, a variety of carbon based nano-fillers has been proposed and employed, individually or in combination in hybrid forms, to approach the desired performance. Nevertheless, a major issue faced lately more seriously due to the interest of industry is on how to incorporate these nano-species into the final composite structure through existing manufacturing processes and infrastructure. This interest originates from several industrial applications needs that request the development of new multi-functional materials which combine enhanced mechanical, electrical and thermal properties. In this work, an attempt is performed to review the most representative processes and related performances reported in literature and the experience obtained on nano-enabling technologies of fiber composite materials. This review focuses on the two main composite manufacturing technologies used by the aerospace industry; Prepreg/Autoclave and Resin Transfer technologies. It addresses several approaches for nano-enabling of composites for these two routes and reports latest achieved results focusing on performance of nano-enabled fiber reinforced composites extracted from literature. Finally, this review work identifies the gap between available nano-technology integration routes and the established industrial composite manufacturing techniques and the challenges to increase the Technology Readiness Level to reach the demands for aerospace industry applications.

  13. A critical review of nanotechnologies for composite aerospace structures

    NASA Astrophysics Data System (ADS)

    Kostopoulos, Vassilis; Masouras, Athanasios; Baltopoulos, Athanasios; Vavouliotis, Antonios; Sotiriadis, George; Pambaguian, Laurent

    2016-07-01

    The past decade extensive efforts have been invested in understanding the nano-scale and revealing the capabilities offered by nanotechnology products to structural materials. Integration of nano-particles into fiber composites concludes to multi-scale reinforced composites and has opened a new wide range of multi-functional materials in industry. In this direction, a variety of carbon based nano-fillers has been proposed and employed, individually or in combination in hybrid forms, to approach the desired performance. Nevertheless, a major issue faced lately more seriously due to the interest of industry is on how to incorporate these nano-species into the final composite structure through existing manufacturing processes and infrastructure. This interest originates from several industrial applications needs that request the development of new multi-functional materials which combine enhanced mechanical, electrical and thermal properties. In this work, an attempt is performed to review the most representative processes and related performances reported in literature and the experience obtained on nano-enabling technologies of fiber composite materials. This review focuses on the two main composite manufacturing technologies used by the aerospace industry; Prepreg/Autoclave and Resin Transfer technologies. It addresses several approaches for nano-enabling of composites for these two routes and reports latest achieved results focusing on performance of nano-enabled fiber reinforced composites extracted from literature. Finally, this review work identifies the gap between available nano-technology integration routes and the established industrial composite manufacturing techniques and the challenges to increase the Technology Readiness Level to reach the demands for aerospace industry applications.

  14. Critical behavior of the quantum Ising model on a fractal structure.

    PubMed

    Yi, Hangmo

    2013-07-01

    We study the critical behavior of the transverse-field quantum Ising model on a fractal structure, namely the Sierpinski carpet. When a magnetic field Δ is applied perpendicular to the Ising spin direction, quantum fluctuations affect the transition between the ferromagnetic and the paramagnetic phases. Employing the continuous-time quantum Monte Carlo simulation method and the finite-size scaling analysis, we investigate the interplay between the quantum fluctuations and the exotic dimensionality of the fractal structure and its effect on the critical behavior. As the transverse magnetic field increases, the critical temperature monotonically decreases until it apparently vanishes at a critical field Δ(c), beyond which the system becomes paramagnetic at all temperatures. However, the critical exponents are independent of Δ and remain the same as in the purely classical(Δ=0) case.

  15. 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.

  16. Structure of an N276-Dependent HIV-1 Neutralizing Antibody Targeting a Rare V5 Glycan Hole Adjacent to the CD4 Binding Site

    SciTech Connect

    Wibmer, Constantinos Kurt; Gorman, Jason; Anthony, Colin S.; Mkhize, Nonhlanhla N.; Druz, Aliaksandr; York, Talita; Schmidt, Stephen D.; Labuschagne, Phillip; Louder, Mark K.; Bailer, Robert T.; Abdool Karim, Salim S.; Mascola, John R.; Williamson, Carolyn; Moore, Penny L.; Kwong, Peter D.; Morris, Lynn; Kirchhoff, F.

    2016-08-31

    ABSTRACT

    All HIV-1-infected individuals develop strain-specific neutralizing antibodies to their infecting virus, which in some cases mature into broadly neutralizing antibodies. Defining the epitopes of strain-specific antibodies that overlap conserved sites of vulnerability might provide mechanistic insights into how broadly neutralizing antibodies arise. We previously described an HIV-1 clade C-infected donor, CAP257, who developed broadly neutralizing plasma antibodies targeting an N276 glycan-dependent epitope in the CD4 binding site. The initial CD4 binding site response potently neutralized the heterologous tier 2 clade B viral strain RHPA, which was used to design resurfaced gp120 antigens for single-B-cell sorting. Here we report the isolation and structural characterization of CAP257-RH1, an N276 glycan-dependent CD4 binding site antibody representative of the early CD4 binding site plasma response in donor CAP257. The cocrystal structure of CAP257-RH1 bound to RHPA gp120 revealed critical interactions with the N276 glycan, loop D, and V5, but not with aspartic acid 368, similarly to HJ16 and 179NC75. The CAP257-RH1 monoclonal antibody was derived from the immunoglobulin-variable IGHV3-33 and IGLV3-10 genes and neutralized RHPA but not the transmitted/founder virus from donor CAP257. Its narrow neutralization breadth was attributed to a binding angle that was incompatible with glycosylated V5 loops present in almost all HIV-1 strains, including the CAP257 transmitted/founder virus. Deep sequencing of autologous CAP257 viruses, however, revealed minority variants early in infection that lacked V5 glycans. These glycan-free V5 loops are unusual holes in the glycan shield that may have been necessary for initiating this N276 glycan-dependent CD4 binding site B-cell lineage.

    IMPORTANCEThe conserved CD4 binding site on gp120 is a major target for HIV-1 vaccine design, but key events in the elicitation and maturation of

  17. Structure of an N276-Dependent HIV-1 Neutralizing Antibody Targeting a Rare V5 Glycan Hole Adjacent to the CD4 Binding Site

    PubMed Central

    Wibmer, Constantinos Kurt; Gorman, Jason; Anthony, Colin S.; Mkhize, Nonhlanhla N.; Druz, Aliaksandr; York, Talita; Schmidt, Stephen D.; Labuschagne, Phillip; Louder, Mark K.; Bailer, Robert T.; Abdool Karim, Salim S.; Mascola, John R.; Williamson, Carolyn; Moore, Penny L.

    2016-01-01

    ABSTRACT All HIV-1-infected individuals develop strain-specific neutralizing antibodies to their infecting virus, which in some cases mature into broadly neutralizing antibodies. Defining the epitopes of strain-specific antibodies that overlap conserved sites of vulnerability might provide mechanistic insights into how broadly neutralizing antibodies arise. We previously described an HIV-1 clade C-infected donor, CAP257, who developed broadly neutralizing plasma antibodies targeting an N276 glycan-dependent epitope in the CD4 binding site. The initial CD4 binding site response potently neutralized the heterologous tier 2 clade B viral strain RHPA, which was used to design resurfaced gp120 antigens for single-B-cell sorting. Here we report the isolation and structural characterization of CAP257-RH1, an N276 glycan-dependent CD4 binding site antibody representative of the early CD4 binding site plasma response in donor CAP257. The cocrystal structure of CAP257-RH1 bound to RHPA gp120 revealed critical interactions with the N276 glycan, loop D, and V5, but not with aspartic acid 368, similarly to HJ16 and 179NC75. The CAP257-RH1 monoclonal antibody was derived from the immunoglobulin-variable IGHV3-33 and IGLV3-10 genes and neutralized RHPA but not the transmitted/founder virus from donor CAP257. Its narrow neutralization breadth was attributed to a binding angle that was incompatible with glycosylated V5 loops present in almost all HIV-1 strains, including the CAP257 transmitted/founder virus. Deep sequencing of autologous CAP257 viruses, however, revealed minority variants early in infection that lacked V5 glycans. These glycan-free V5 loops are unusual holes in the glycan shield that may have been necessary for initiating this N276 glycan-dependent CD4 binding site B-cell lineage. IMPORTANCE The conserved CD4 binding site on gp120 is a major target for HIV-1 vaccine design, but key events in the elicitation and maturation of different antibody lineages to this site

  18. The Emergent Structure of Feeling: What Does It Mean for Critical Educational Studies and Research?

    ERIC Educational Resources Information Center

    Lingard, Bob; Gale, Trevor

    2007-01-01

    Critical research in education is not what it used to be. It must now engage with a differently structured and globalized world with different social and material conditions for its peoples. This paper sets out to name the contemporary structure of feeling in which education researchers now work, particularly in terms of what now is to be the…

  19. Maximum-entropy large-scale structures of Boolean networks optimized for criticality

    NASA Astrophysics Data System (ADS)

    Möller, Marco; Peixoto, Tiago P.

    2015-04-01

    We construct statistical ensembles of modular Boolean networks that are constrained to lie at the critical line between frozen and chaotic dynamic regimes. The ensembles are maximally random given the imposed constraints, and thus represent null models of critical networks. By varying the network density and the entropic cost associated with biased Boolean functions, the ensembles undergo several phase transitions. The observed structures range from fully random to several ordered ones, including a prominent core-periphery-like structure, and an 'attenuated' two-group structure, where the network is divided in two groups of nodes, and one of them has Boolean functions with very low sensitivity. This shows that such simple large-scale structures are the most likely to occur when optimizing for criticality, in the absence of any other constraint or competing optimization criteria.

  20. 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

  1. Teaching critical thinking for transfer across domains. Dispositions, skills, structure training, and metacognitive monitoring.

    PubMed

    Halpern, D F

    1998-04-01

    Advances in technology and changes in necessary workplace skills have made the ability to think critically more important than ever before, yet there is ample evidence that many adults consistently engage in flawed thinking. Numerous studies have shown that critical thinking, defined as the deliberate use of skills and strategies that increase the probability of a desirable outcome, can be learned in ways that promote transfer to novel contexts. A 4-part empirically based model is proposed to guide teaching and learning for critical thinking: (a) a dispositional component to prepare learners for effortful cognitive work, (b) instruction in the skills of critical thinking, (c) training in the structural aspects of problems and arguments to promote transcontextual transfer of critical-thinking skills, and (d) a metacognitive component that includes checking for accuracy and monitoring progress toward the goal.

  2. Critical current and electric transport properties of superconducting epitaxial Nb(Ti)N submicron structures

    NASA Astrophysics Data System (ADS)

    Klimov, A.; Słysz, W.; Guziewicz, M.; Kolkovsky, V.; Wegrzecki, M.; Bar, J.; Marchewka, M.; Seredyński, B.

    2016-12-01

    Critical current and current-voltage characteristics of epitaxial Nb(Ti)N submicron ultrathin structures were measured as function of temperature. For 700-nm-wide bridge we found current-driven vortex de-pinning at low temperatures and thermally activated flux flow closer to the transition temperature, as the limiting factors for the critical current density. For 100-nm-wide meander we observed combination of phase-slip activation and vortex-anti-vortex pair (VAP) thermal excitation. Our Nb(Ti)N meander structure demonstrates high de-pairing critical current densities 107 A/cm2 at low temperatures, but the critical currents are much smaller due to presence of the local constrictions.

  3. 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.

  4. SU-E-T-346: Effect of Jaw Position On Dose to Critical Structures in 3-D Conformal Radiotherapy Treatment of Pancreatic Cancer

    SciTech Connect

    Paudel, N; Han, E; Liang, X; Morrill, S; Zhang, X; Hardee, M; Penagaricano, J; Ratanatharathorn, V

    2015-06-15

    Purpose: Three-dimensional conformal therapy remains a valid and widely used modality for pancreatic radiotherapy treatment. It usually meets dose constraints on critical structures. However, careful positioning of collimation jaws can reduce dose to the critical structures. Here we investigate the dosimetric effect of jaw position in MLC-based 3-D conformal treatment planning on critical structures. Methods: We retrospectively selected seven pancreatic cancer patients treated with 3-D conformal radiotherapy. We started with treatment plans (Varian Truebeam LINAC, Eclipse TPS, AAA, 18MV) having both x and y jaws aligned with the farthest extent of the block outline (8mm around PTV). Then we subsequently moved either both x-jaws or all x and y jaws outwards upto 3 cm in 1 cm increments and investigated their effect on average and maximum dose to neighboring critical structures keeping the same coverage to treatment volume. Results: Lateral displacement of both x-jaws by 1cm each increased kidney and spleen mean dose by as much as 1.7% and 1.3% respectively and superior inferior displacement increased liver, right kidney, stomach and spleen dose by as much as 2.1%, 2%, 5.2% and 1.6% respectively. Displacement of all x and y-jaws away by 1cm increased the mean dose to liver, right kidney, left kidney, bowels, cord, stomach and spleen by as much as 4.9%, 5.9%, 2.1%, 2.8%, 7.4%, 10.4% and 4.2% respectively. Percentage increase in mean dose due to 2 and 3cm jaw displacement increased almost linearly with the displaced distance. Changes in maximum dose were much smaller (mostly negligible) than the changes in mean dose. Conclusion: Collimation jaw position affects dose mostly to critical structures adjacent to it. Though treatment plans with MLCs conforming the block margin usually meet dose constraints to critical structures, keeping jaws all the way in, to the edge of the block reduces dose to the critical structures during radiation treatment.

  5. 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.

  6. Judgments of Information Structure in L2 French: Nativelike Performance and the Critical Period Hypothesis

    ERIC Educational Resources Information Center

    Reichle, Robert V.

    2010-01-01

    Previous studies using judgments of morphosyntactic errors have shown mixed evidence for a critical period for L2 acquisition (e.g., Birdsong & Molis, Journal of Memory and Language 44: 235-249, 2001, Johnson & Newport, Cognitive Psychology 21: 60-99, 1989). This study uses anomalies in the domain of information structure, the interface…

  7. 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…

  8. Atomic and Molecular Structure in Chemical Education: A Critical Analysis from Various Perspectives of Science Education.

    ERIC Educational Resources Information Center

    Tsaparlis, Georgios

    1997-01-01

    Provides a critical analysis of the role that atomic theory plays in the science curriculum from elementary through secondary school. Examines structural concepts from the perspective of the theory of meaningful learning, information processing theory, and the alternative conceptions movement. Contains 54 references. (DDR)

  9. 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)

  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. Wireless structural health monitoring for critical members of civil infrastructures using piezoelectric active sensors

    NASA Astrophysics Data System (ADS)

    Park, Seunghee; Yun, Chung-Bang; Inman, Daniel J.; Park, Gyuhae

    2008-03-01

    This paper presents several challenging issues on wireless structural health monitoring techniques for critical members of civil infrastructures using piezoelectric active sensors. The basic concept of the techniques is to monitor remotely the structural integrity by observing the impedance variations at the piezoelectric active sensors distributed to critical members of a host structure. An active sensing node incorporating on-board microprocessor and radio frequency telemetry is introduced in a sense of tailoring wireless sensing technology to the impedance method. A data compression algorithm using principal component analysis is embedded into the on-board chip of the active sensing node. The data compression algorithm would promote efficiency in terms of both power management and noise elimination of the active sensor node. Finally, a piezoelectric sensor self-diagnosis issue is touched introducing a new impedance model equation that incorporates the effects of sensor and bonding defects.

  12. 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.

  13. Pressure effects on the electronic structure and superconducting critical temperature of Li2B2.

    PubMed

    Martínez-Guerra, E; Ortíz-Chi, F; Curtarolo, S; de Coss, R

    2014-03-19

    We present the structural, electronic and superconducting properties of Li2B2 under pressure within the framework of the density functional theory. The structural parameters, electronic band structure, phonon frequency of the E2g phonon mode and superconducting critical temperature Tc were calculated for pressures up to 20 GPa. We predicted that the superconducting critical temperature of Li2B2 is about 11 K and this decreases as pressure increases. We found that even though the lattice dynamics of the E2g phonon mode is similar to MgB2, the reduction of the σ-band density of states at Fermi level and the raising of the E2g phonon frequency with pressure were determinant to decrease λ and consequently Tc.

  14. 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

  15. 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.

  16. 15. View north from the adjacent B & O railroad ...

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

    15. View north from the adjacent B & O railroad bridge of Pier No. 5 and portion of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  17. 7. View north from the adjacent B & O railroad ...

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

    7. View north from the adjacent B & O railroad bridge of Pier No. 1 and portions of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  18. 8. View north from the adjacent B & O railroad ...

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

    8. View north from the adjacent B & O railroad bridge of Pier No. 2 and portions of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  19. Evaluating upper versus lower crustal extension through structural reconstructions and subsidence analysis of basins adjacent to the D'Entrecasteaux Islands, eastern Papua New Guinea

    NASA Astrophysics Data System (ADS)

    Fitz, Guy; Mann, Paul

    2013-06-01

    The D'Entrecasteaux Island (DEI) gneiss domes are fault-bounded domes with ~2.5 km of relief exposing ultrahigh-pressure (UHP) and high-pressure (HP) metamorphic gneisses and migmatites exhumed in an Oligocene-Miocene arc-continent collision and subduction zone subject to late Miocene to recent continental extension. Multichannel seismic reflection data and well data show the Trobriand basin formed as a fore-arc basin caused by southward Miocene subduction at the Trobriand trench. Subduction slowed at ~8 Ma as the margin transitioned to an extensional tectonic environment. Since then, the Trobriand basin has subsided 1-2.5 km as a broad sag basin with few normal faults deforming the basin fill. South of the DEI, the Goodenough rift basin developed after extension began (~8 Ma) as the hanging wall of the north-dipping Owen-Stanley normal fault that bounds the basin's southern margin. The lack of upper crustal extension accompanying subsidence in the Trobriand and Goodenough basins suggests depth-dependent lithospheric extension since 8 Ma has accompanied uplift of the DEI gneiss domes. Structural reconstructions of seismic profiles show 2.3-13.4 km of basin extension in the upper crust, while syn-rift basin subsidence values indicate at least 20.7-23.6 km of extension occurred in the entire crust since ~8 Ma. Results indicating thinning is preferentially accommodated in the lower crust surrounding the DEI are used to constrain a schematic model of uplift of the DEI domes involving vertical exhumation of buoyant, postorogenic lower crust, far-field extension from slab rollback, and an inverted two-layer crustal density structure.

  20. 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.

  1. 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

  2. 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.

  3. Genetic structure of Sakhalin spruce (Picea glehnii) in northern Japan and adjacent regions revealed by nuclear microsatellites and mitochondrial gene sequences.

    PubMed

    Aizawa, Mineaki; Yoshimaru, Hiroshi; Takahashi, Makoto; Kawahara, Takayuki; Sugita, Hisashi; Saito, Hideyuki; Sabirov, Renat N

    2015-01-01

    The genetic structure of Sakhalin spruce (Picea glehnii) was studied across the natural range of the species, including two small isolated populations in south Sakhalin and Hayachine, by using six microsatellite loci and maternally inherited mitochondrial gene sequences. We also analyzed P. jezoensis, a sympatric spruce in the range. Genetic diversity of P. glehnii was higher in central Hokkaido and the lowest in the Hayachine. Bayesian clustering and principal coordinate analysis by using the microsatellites indicated that the Hayachine was clearly distinct from other populations, implying that it had undergone strong genetic drift since the last glacial period. P. glehnii harbored four mitochondrial haplotypes, two of which were shared with P. jezoensis. One of the two was observed without geographical concentration, suggesting its derivation from ancestral polymorphism. Another was observed in south Sakhalin and in P. jezoensis across Sakhalin. The Bayesian clustering--by using four microsatellite loci, including P. jezoensis populations--indicated unambiguous species delimitation, but with possible admixture of P. jezoensis genes into P. glehnii in south Sakhalin, where P. glehnii is abundantly overwhelmed by P. jezoensis; this might explain the occurrence of introgression of the haplotype of P. jezoensis into P. glehnii.

  4. Impact of Surgical Evaluation of Additional Cine Magnetic Resonance Imaging for Advanced Thymoma with Infiltration of Adjacent Structures: The Thoracic Surgeon's View.

    PubMed

    Ried, Michael; Hnevkovsky, Stefanie; Neu, Reiner; von Süßkind-Schwendi, Marietta; Götz, Andrea; Hamer, Okka W; Schalke, Berthold; Hofmann, Hans-Stefan

    2017-04-01

    Background Preoperative radiological assessment is important for clarification of surgical operability for advanced thymic tumors. Objective was to determine the feasibility of magnetic resonance imaging (MRI) with cine sequences for evaluation of cardiovascular tumor invasion. Patients and Methods This prospective study included patients with advanced thymoma, who underwent surgical resection. All patients received preoperative computed tomography (CT) scan and cine MRI. Results Tumor infiltration was surgically confirmed in the pericardium (n = 12), myocardium (n = 1), superior caval vein (SCV; n = 3), and aorta (n = 2). A macroscopic complete resection was possible in 10 patients, whereas 2 patients with aortic or myocardial tumor invasion had R2 resection. The positive predictive value (PPV) was 50% for cine MRI compared with 0% for CT scan regarding myocardial tumor infiltration. The PPV for tumor infiltration of the aorta was 50%, with a higher sensitivity for the CT scan (100 vs. 50%). Infiltration of the SCV could be detected slightly better with cine MRI (PPV 75 vs. 66.7%). Conclusion Cine MRI seems to improve the accuracy of preoperative staging of advanced thymoma regarding infiltration of cardiovascular structures and supports the surgical approach.

  5. Dynamical Signatures of Structural Connectivity Damage to a Model of the Brain Posed at Criticality.

    PubMed

    Haimovici, Ariel; Balenzuela, Pablo; Tagliazucchi, Enzo

    2016-12-01

    Synchronization of brain activity fluctuations is believed to represent communication between spatially distant neural processes. These interareal functional interactions develop in the background of a complex network of axonal connections linking cortical and subcortical neurons, termed the human "structural connectome." Theoretical considerations and experimental evidence support the view that the human brain can be modeled as a system operating at a critical point between ordered (subcritical) and disordered (supercritical) phases. Here, we explore the hypothesis that pathologies resulting from brain injury of different etiologies are related to this model of a critical brain. For this purpose, we investigate how damage to the integrity of the structural connectome impacts on the signatures of critical dynamics. Adopting a hybrid modeling approach combining an empirical weighted network of human structural connections with a conceptual model of critical dynamics, we show that lesions located at highly transited connections progressively displace the model toward the subcritical regime. The topological properties of the nodes and links are of less importance when considered independently of their weight in the network. We observe that damage to midline hubs such as the middle and posterior cingulate cortex is most crucial for the disruption of criticality in the model. However, a similar effect can be achieved by targeting less transited nodes and links whose connection weights add up to an equivalent amount. This implies that brain pathology does not necessarily arise due to insult targeted at well-connected areas and that intersubject variability could obscure lesions located at nonhub regions. Finally, we discuss the predictions of our model in the context of clinical studies of traumatic brain injury and neurodegenerative disorders.

  6. 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

  7. 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.

  8. Identifying the Critical Links in Road Transportation Networks: Centrality-based approach utilizing structural properties

    SciTech Connect

    Chinthavali, Supriya

    2016-04-01

    Surface transportation road networks share structural properties similar to other complex networks (e.g., social networks, information networks, biological networks, and so on). This research investigates the structural properties of road networks for any possible correlation with the traffic characteristics such as link flows those determined independently. Additionally, we define a criticality index for the links of the road network that identifies the relative importance in the network. We tested our hypotheses with two sample road networks. Results show that, correlation exists between the link flows and centrality measures of a link of the road (dual graph approach is followed) and the criticality index is found to be effective for one test network to identify the vulnerable nodes.

  9. 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

  10. 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

  11. Geologic structure and occurrence of gas in part of southwestern New York. Part 1, Structure and gas possibilities of the Oriskany sandstone in Steuben, Yates, and parts of the adjacent counties

    USGS Publications Warehouse

    Bradley, W.H.; Pepper, J.F.

    1941-01-01

    The area covered by this report is in southwestern New York and includes a little more than 3,000 square miles in Steuben and Yates counties and parts of the six adjacent counties. This area has been mapped to determine the structural attitude of the exposed rocks, so as to aid those interested in prospecting for natural gas in the Oriskany sandstone of Lower Devonian age.Because of the gentle regional dip toward the southwest, the youngest beds are exposed in the southwest corner of the area, and progressively older beds crop out northeastward in successive bands that strike generally northwest. All the exposed rocks are of Upper Devonian age except those in a narrow belt at the extreme north edge of the area, where a small thickness of Middle Devonian rocks crops out. The maximum thickness of beds so exposed is nearly 4,000 feet, of which the lower part is predominantly soft dark shale and the upper part predominantly fine-grained sandstone and gray shale. All the beds are marine except a few tongues of continental deposits red shale and sandstone and gray mudstone in the youngest beds. All the beds thicken southeastward, so that there is a northwestward convergence between any two lithologic units in the series. More than 30 key horizons that are persistent and distinctive were mapped, and altitudes on these key horizons served as a basis for constructing the structure contour map. Many of the key horizons are formation or member boundaries, but others are the tops or bottoms of limestone or sandstone beds within formations. All the stratigraphic units mapped are purely lithologic. (See pi. 2.)The Tully limestone, which crops out along the northern border of the area, is an easily recognizable and therefore valuable key bed for subsurface correlations in this part of the State. Below the Tully limestone is a thick body of Middle Devonian shales of the Hamilton group which rests on another valuable key bed, the hard, cherty Onondaga limestone, also of Middle

  12. Ion Dynamics and Field Structure of Quasi-perpendicular Collisionless Shocks near the Critical Mach Number

    NASA Astrophysics Data System (ADS)

    Balikhin, M. A.; Malkov, M.; Sagdeev, R.; Dudnikova, G.

    2015-12-01

    The structure of subcritical (laminar) collisionless shocks has been understood long time ago. When the Mach number exceeds a critical value, some of the incident ions are reflected. This needs to be included into the description of the shock structure and entropy production at the shock front. We present an analytical model of ion reflection from a quasi-perpendicular collisionless shock and the formation of the foot region associated with this reflection. Reflected ions perturb the electrostatic and magnetic fields in the foot region which we self-consistently include in determining the fraction of reflected ions, depending on the Mach number of the shock. The subsequent motion of the shock reflected ions downstream and formation of the downstream field structure is analyzed. Models for thermalization of the downstream plasma and approaches to Rankine-Hugoniot relations will also be discussed. The obtained overall shock structure is compared with the Cluster observations.

  13. 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

  14. 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.

  15. 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.

  16. Critical Soil-Structure Interaction Analysis Considerations for Seismic Qualification of Safety Equipment

    SciTech Connect

    Hossain, Q A

    2004-03-04

    While developing seismic analysis models for buildings that support safety-related equipment, a number of issues should be considered to ensure that the input motions for performing seismic qualification of safety-related equipment are properly defined. These considerations are listed and discussed here with special attention to the effect and importance of the interaction among the foundation soil, the building structure, the equipment anchors, and the equipment structure. Typical industry practices are critically examined to assess their adequacy for determining the input motions for equipment seismic qualification. The features that are considered essential in a soil-structure interaction (SSI) model are described. Also, the effects of inappropriate treatment or representation of these features are discussed.

  17. 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

  18. 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

  19. 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.

  20. Finite-temperature scaling of trace distance discord near criticality in spin diamond structure

    NASA Astrophysics Data System (ADS)

    Cheng, W. W.; Wang, X. Y.; Sheng, Y. B.; Gong, L. Y.; Zhao, S. M.; Liu, J. M.

    2017-02-01

    In this work we explore the quantum correlation quantified by trace distance discord as a measure to analyze the quantum critical behaviors in the Ising-XXZ diamond structure at finite temperatures. It is found that the first-order derivative of the trace distance discord exhibits a maximum around the critical point at finite temperatures. By analyzing the finite-temperature scaling behavior, we show that such a quantum correlation can detect exactly the quantum phase transitions from the entan-gled state in ferrimagnetic phase to an unentangled state in ferrimagnetic phase or to an unentangled state in ferromagnetic phase. The results also indicate that the above two kinds of transitions can be distinguished by the different finite-temperature scaling behaviors. Moreover, we find that the trace distance discord, in contrast to other typical quantum correlations (e.g., concurrence, quantum discord and Hellinger distance), may be more reliable to exactly spotlight the critical points of this model at finite temperatures under certain situations.

  1. Finite-temperature scaling of trace distance discord near criticality in spin diamond structure

    PubMed Central

    Cheng, W. W.; Wang, X. Y.; Sheng, Y. B.; Gong, L. Y.; Zhao, S. M.; Liu, J. M.

    2017-01-01

    In this work we explore the quantum correlation quantified by trace distance discord as a measure to analyze the quantum critical behaviors in the Ising-XXZ diamond structure at finite temperatures. It is found that the first-order derivative of the trace distance discord exhibits a maximum around the critical point at finite temperatures. By analyzing the finite-temperature scaling behavior, we show that such a quantum correlation can detect exactly the quantum phase transitions from the entan-gled state in ferrimagnetic phase to an unentangled state in ferrimagnetic phase or to an unentangled state in ferromagnetic phase. The results also indicate that the above two kinds of transitions can be distinguished by the different finite-temperature scaling behaviors. Moreover, we find that the trace distance discord, in contrast to other typical quantum correlations (e.g., concurrence, quantum discord and Hellinger distance), may be more reliable to exactly spotlight the critical points of this model at finite temperatures under certain situations. PMID:28198404

  2. 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.

  3. 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.

  4. Target Highlights in CASP9: Experimental Target Structures for the Critical Assessment of Techniques for Protein Structure Prediction

    PubMed Central

    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.; Jayaraman, Seetharaman; 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, i.e. 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 manuscript, 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 fibre protein gp37 from bacteriophage T4, the cyclic GMP-dependent protein kinase Iβ (PKGIβ) dimerization/docking domain, the ectodomain of the JTB (Jumping Translocation Breakpoint) transmembrane receptor, Autotaxin (ATX) in complex with an inhibitor, the DNA-Binding J-Binding Protein 1 (JBP1) 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 (PBS) core-membrane linker (LCM) phycobiliprotein ApcE from Synechocystis, the Heat shock protein 90 (Hsp90) activators PFC0360w and PFC0270w from Plasmodium falciparum, and 2-oxo-3-deoxygalactonate kinase from Klebsiella pneumoniae. PMID:22020785

  5. Critical joints in large composite primary aircraft structures. Volume 1: Technical summary

    NASA Technical Reports Server (NTRS)

    Bunin, Bruce L.

    1985-01-01

    A program was conducted at Douglas Aircraft Company to develop the technology for critical joints in composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. In fulfilling this objective, analytical procedures for joint design and analysis were developed during Phase 1 of the program. Tests were conducted at the element level to supply the empirical data required for methods development. Large composite multirow joints were tested to verify the selected design concepts and for correlation with analysis predictions. The Phase 2 program included additional tests to provide joint design and analysis data, and culminated with several technology demonstration tests of a major joint area representative of a commercial transport wing. The technology demonstration program of Phase 2 is discussed. The analysis methodology development, structural test program, and correlation between test results and analytical strength predictions are reviewed.

  6. Structural Stability of Planar Homogeneous Polynomial Vector Fields: Applications to Critical Points and to Infinity

    NASA Astrophysics Data System (ADS)

    Llibre, Jaume; Pérez del Río, Jesús S.; Rodríguez, José Angel

    1996-03-01

    LetHmbe the space of planar homogeneous polynomial vector fields of degreemendowed with the coefficient topology. We characterize the setΩmof the vector fields ofHmthat are structurally stable with respect to perturbations inHmand we determine the exact number of the topological equivalence classes inΩm. The study of structurally stable homogeneous polynomial vector fields is very useful for understanding some interesting features of inhomogeneous vector fields. Thus, by using this characterization we can do first an extension of the Hartman-Grobman Theorem which allows us to study the critical points of planar analytical vector fields whosek-jets are zero for allk

  7. 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

    2016-06-10

    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.

  8. 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.

  9. 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.

  10. 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.

  11. Urinary clearance of albumin is critically determined by its tertiary structure.

    PubMed

    Clavant, Steven P; Comper, Wayne D

    2003-12-01

    The excretion of serum albumin in the urine is considered the net result of renal glomerular filtration and tubular uptake. During routine experiments, we observed that a batch of tritium-labeled albumin yielded anomalous results, being excreted in the urine of isolated perfused kidneys at 10 times the rate of normal tritiated albumin. This anomalous albumin, when simultaneously studied with normal carbon 14-labeled albumin, exhibited 10 times greater excretion than normal [(14)C]albumin. Anomalous albumin could not be reversed to normal albumin by means of conditioning with blood. In vivo clearances of anomalous albumin could not be quantitated because anomalous albumin is degraded during circulation. Anomalous albumin appeared to have the same molecular size (as determined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, capillary electrophoresis, and gel chromatography) and isoelectric-point profile (2-dimensional electrophresis) as normal albumin. Normal albumin could be transformed to anomalous albumin with alkali/heat treatment. Reverse-phase high-pressure liquid chromatography analysis of fragments from tryptic digests of anomalous albumin, alkali/heat-treated albumin, and normal albumin suggest that anomalous albumin and alkali/heat-treated albumin have altered tertiary structure, possibly as a result of denaturation and disulfide exchange. These studies show that the tertiary structure of albumin, beyond simple size and charge, is a critical determinant for albumin processing by the kidney and suggest that a specific albumin-recognition event by the kidneys is critical to normal renal handling of albumin.

  12. Genetic variation and structure in remnant population of critically endangered Melicope zahlbruckneri

    USGS Publications Warehouse

    Raji, J. A.; Atkinson, Carter T.

    2016-01-01

    The distribution and amount of genetic variation within and between populations of plant species are important for their adaptability to future habitat changes and also critical for their restoration and overall management. This study was initiated to assess the genetic status of the remnant population of Melicope zahlbruckneri–a critically endangered species in Hawaii, and determine the extent of genetic variation and diversity in order to propose valuable conservation approaches. Estimated genetic structure of individuals based on molecular marker allele frequencies identified genetic groups with low overall differentiation but identified the most genetically diverse individuals within the population. Analysis of Amplified Fragment Length Polymorphic (AFLP) marker loci in the population based on Bayesian model and multivariate statistics classified the population into four subgroups. We inferred a mixed species population structure based on Bayesian clustering and frequency of unique alleles. The percentage of Polymorphic Fragment (PPF) ranged from 18.8 to 64.6% for all marker loci with an average of 54.9% within the population. Inclusion of all surviving M. zahlbruckneri trees in future restorative planting at new sites are suggested, and approaches for longer term maintenance of genetic variability are discussed. To our knowledge, this study represents the first report of molecular genetic analysis of the remaining population of M. zahlbruckneri and also illustrates the importance of genetic variability for conservation of a small endangered population.

  13. 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.

  14. 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…

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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.

  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. 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.

  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. 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.

  4. Density dependence in an age-structured population of great tits: identifying the critical age classes.

    PubMed

    Gamelon, Marlène; Grøtan, Vidar; Engen, Steinar; Bjørkvoll, Eirin; Visser, Marcel E; Saether, Bernt-Erik

    2016-09-01

    Classical approaches for the analyses of density dependence assume that all the individuals in a population equally respond and equally contribute to density dependence. However, in age-structured populations, individuals of different ages may differ in their responses to changes in population size and how they contribute to density dependence affecting the growth rate of the whole population. Here we apply the concept of critical age classes, i.e., a specific scalar function that describes how one or a combination of several age classes affect the demographic rates negatively, in order to examine how total density dependence acting on the population growth rate depends on the age-specific population sizes. In a 38-yr dataset of an age-structured great tit (Parus major) population, we find that the age classes, including the youngest breeding females, were the critical age classes for density regulation. These age classes correspond to new breeders that attempt to take a territory and that have the strongest competitive effect on other breeding females. They strongly affected population growth rate and reduced recruitment and survival rates of all breeding females. We also show that depending on their age class, females may differently respond to varying density. In particular, the negative effect of the number of breeding females was stronger on recruitment rate of the youngest breeding females. These findings question the classical assumptions that all the individuals of a population can be treated as having an equal contribution to density regulation and that the effect of the number of individuals is age independent. Our results improve our understanding of density regulation in natural populations.

  5. Stereotactic radiotherapy using Novalis for craniopharyngioma adjacent to optic pathways.

    PubMed

    Hashizume, Chisa; Mori, Yoshimasa; Kobayashi, Tatsuya; Shibamoto, Yuta; Nagai, Aiko; Hayashi, Naoki

    2010-06-01

    Craniopharyngioma has benign histological character. However, because of proximity to optic pathways, pituitary gland, and hypothalamus, it may cause severe and permanent damage to such critical structures and can even be life threatening. Total surgical resection is often difficult. This study aims to evaluate treatment results of Novalis stereotactic radiotherapy (SRT) for craniopharyngioma adjacent to optic pathways. Ten patients (six men, four women) with craniopharyngioma and median age of 56.5 years (range 10-74 years) were treated by SRT using Novalis from July 2006 through March 2009. Median volume of tumor was 7.9 ml (range 1.1-21 ml). Three-dimensional noncoplanar five- or seven-beam SRT or coplanar five-beam SRT with intensity modulation was performed. Total dose of 30-39 Gy in 10-15 fractions (median 33 Gy) was delivered to the target. Ten patients were followed up for 9-36 months (median 25.5 months). Response rate was 80% (8/10), and control rate was 100%. Improvement of neurological symptoms was observed in five patients. No serious complications due to SRT were found. SRT for craniopharyngioma may be a safe and effective treatment. Longer follow-up is necessary to determine long-term tumor control or late complications.

  6. 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.

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

    PubMed

    Senturia, Rachel; Faller, Michael; Yin, Sheng; Loo, Joseph A; Cascio, Duilio; Sawaya, Michael R; Hwang, Daniel; Clubb, Robert T; Guo, Feng

    2010-07-01

    Maturation of microRNAs (miRNAs, approximately 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 A 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.

  8. Interaction of Adjacent Amino Acids

    NASA Astrophysics Data System (ADS)

    Sheu, Sheh-Yi; Yang, Dah-Yen

    2008-02-01

    Ramachandran plots display the dihedral angles of a single protein residue. We here propose a crossed torsion angle plot called SSY-plot between two neighboring amino acids and demonstrate that a special coherence motion can exist between some very special amino acid pairs leading to spontaneous unusual structures. We also suggest that the existence of two domains corresponds to a bifurcation between two different protein structures and that the special pair is the key to producing these two structures. These are two different structures and are produced spontaneously without an external agent.

  9. 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

  10. If You Structure It, They Will Learn ...: Critical Thinking in Physical Education Classes

    ERIC Educational Resources Information Center

    McBride, Ron E.

    2004-01-01

    Though in its infancy, research on the use of critical thinking in physical education has shown promising results. To many, the notion of combining critical thinking and physical education might even be seen as a contradiction in terms. This article explores the dispositional aspect of critical thinking and asks two questions: (1) Are students…

  11. Critical taper wedge strength varies with structural style: results from distinct-element models

    NASA Astrophysics Data System (ADS)

    Strayer, L. M.; Suppe, J.

    2015-12-01

    Critical-taper theory has given diverse insight into kinematics, roles of erosion and sedimentation, and the morphology of compressive mountain belts. We have made progress by recasting the parameter-rich mathematics into a simpler form that describes a linear, co-varying relationship between surface slope and detachment dip (α, β), and internal- and basal-sliding strengths (W, F). Using distinct-element models, we tested this simpler theory over a range of wedge strengths and structural styles. We also obtained W & F from observations of surface slope α and detachment dip β in active natural systems, all of which including the numerical models, show wedges are strong but detachments are weak, with F/W=0.1 or less. Model-derived W & F vary about a mean that matches geometry-derived values. Time- and spatially-averaged dynamical F & W are observed to be equal to wedge-derived results. Critical taper reflects the dynamical strengths during wedge growth and is controlled dynamically as base friction varies between an assigned quasi-static value and lower values during slip events. In the wedge, W varies more than F, which may also be true for natural systems. Detachments have frictional stick/slip behavior on a basal wall, but the wedge has more going on within it. Tandem faulting & folding serve to simultaneously weaken and strengthen the wedge, and may occur anywhere: structural style appears to be important to wedge strength evolution. The dynamics of deformation within the wedge and slip upon the base control the finite wedge geometry: static strengths drop to dynamic levels during seismicity, resulting in materials and faults that are weaker than prescribed in models or determined by testing. Relationships between α and W & F are complex. All sudden, stepwise changes in α, W & F with time coincide with seismicity spikes in the models. Large events trigger or are triggered by large changes in F and W. We examine the complex details of dynamically driven

  12. 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.

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

    PubMed

    Moosavi, S Amin; Montakhab, Afshin

    2015-01-01

    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.

  14. 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.

  15. 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 OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  16. 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 OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  17. 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 OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  18. 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...

  19. 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...

  20. On the quantum critical behaviour of a model of structural phase transitions with long-range interaction

    NASA Astrophysics Data System (ADS)

    Pisanova, E. S.; Tonchev, N. S.

    2010-11-01

    The pure quantum limit of an exactly solvable lattice model describing structural phase transitions in an anharmonic crystal with long-range interaction is considered. At the upper quantum critical dimension the free energy density at T = 0 in the neighbourhood of the quantum critical point is exactly calculated in terms of the Lambert W-function. For the three real physical dimensions, the exact results, obtained here, and the asymptotic ones are compared. It is pointed out that the Lambert W-function turns out to be a very effective tool for an exact computation of non-universal characteristics in the upper critical dimensions, especially in a broader neighbourhood of the critical region.

  1. 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…

  2. Exploring the Structure of the Watson-Glaser Critical Thinking Appraisal: One Scale or Many Subscales?

    ERIC Educational Resources Information Center

    Bernard, Robert M.; Zhang, Dai; Abrami, Philip C.; Sicoly, Fiore; Borokhovski, Evgueni; Surkes, Michael A.

    2008-01-01

    Critical thinking (CT) has been of longstanding interest among scholars, educators, and others who are concerned with thinking skills. The Watson-Glaser Critical Thinking Appraisal (WGCTA) is the oldest and among the most widely used and studied CT measure. It was constructed around five subscales (or CT skills): inference, recognition of…

  3. 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

  4. 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…

  5. Examining the Relationship between Middle School Students' Critical Reading Skills, Science Literacy Skills and Attitudes: A Structural Equation Modeling

    ERIC Educational Resources Information Center

    Karademir, Ersin; Ulucinar, Ufuk

    2017-01-01

    The purpose of this study is to verify the causal relationship between middle school students' critical reading skills, science literacy skills and attitudes towards science literacy with research data according to the default model. Through the structural equation modeling, path analysis has been applied in the study which was designed in…

  6. Residue network in protein native structure belongs to the universality class of a three-dimensional critical percolation cluster.

    PubMed

    Morita, Hidetoshi; Takano, Mitsunori

    2009-02-01

    Single protein molecules are regarded as contact networks of amino-acid residues. Relationships between the shortest path lengths and the numbers of residues within single molecules in the native structures are examined for various sized proteins. A universal scaling among proteins is obtained, which shows that the residue networks are fractal networks. This universal fractal network is characterized with three kinds of dimensions: the network topological dimension D{c} approximately 1.9 , the fractal dimension D{f} approximately 2.5 , and the spectral dimension D{s} approximately 1.3 . These values are in surprisingly good coincidence with those of the three-dimensional critical percolation cluster. Hence the residue contact networks in the protein native structures belong to the universality class of the three-dimensional percolation cluster. The criticality is relevant to the ambivalence in the protein native structures, the coexistence of stability and instability, both of which are necessary for protein functions.

  7. Residue network in protein native structure belongs to the universality class of a three-dimensional critical percolation cluster

    NASA Astrophysics Data System (ADS)

    Morita, Hidetoshi; Takano, Mitsunori

    2009-02-01

    Single protein molecules are regarded as contact networks of amino-acid residues. Relationships between the shortest path lengths and the numbers of residues within single molecules in the native structures are examined for various sized proteins. A universal scaling among proteins is obtained, which shows that the residue networks are fractal networks. This universal fractal network is characterized with three kinds of dimensions: the network topological dimension Dc≈1.9 , the fractal dimension Df≈2.5 , and the spectral dimension Ds≈1.3 . These values are in surprisingly good coincidence with those of the three-dimensional critical percolation cluster. Hence the residue contact networks in the protein native structures belong to the universality class of the three-dimensional percolation cluster. The criticality is relevant to the ambivalence in the protein native structures, the coexistence of stability and instability, both of which are necessary for protein functions.

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

    PubMed

    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.

  9. 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

  10. Impact of patient rotational errors on target and critical structure dose in IMRT: A 3D simulation study

    NASA Astrophysics Data System (ADS)

    Arumugam, S.; Xing, A.; Vial, P.; Scotti, A.; Stirton, R.; Goozee, G.; Holloway, Lois

    2013-06-01

    The impact of 3D rotational errors in patient positioning on dose delivered target volumes and critical structures in IMRT was studied. Patient rotational errors ranging from -30 to +30 was introduced to IMRT treatment plans of pelvis, head and neck and brain treatment sites and the impact of rotational error on DVH metrics was assessed. The magnitude of impact of rotational error on the error in dose delivered to the target volume and critical structures depends on the location of the structures from plan isocentre. In studied plans, a maximum percentage difference of up to -9.8(1s=13.4) % in D95 to PTV was observed for head and neck treatments. Similarly, in Brain treatments a maximum difference of up to 24.0(1s=33.0) % in maximum dose of Optic chiasm was observed. The results suggest that failure to correct patient's rotational error results in under-dosage to target volumes and over-dosage to the critical structures in some specific treatment scenarios.

  11. 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.

  12. 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, and…

  13. 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

  14. Processing multiple non-adjacent dependencies: evidence from sequence learning.

    PubMed

    de Vries, Meinou H; Petersson, Karl Magnus; Geukes, Sebastian; Zwitserlood, Pienie; Christiansen, Morten H

    2012-07-19

    Processing non-adjacent dependencies is considered to be one of the hallmarks of human language. Assuming that sequence-learning tasks provide a useful way to tap natural-language-processing mechanisms, we cross-modally combined serial reaction time and artificial-grammar learning paradigms to investigate the processing of multiple nested (A(1)A(2)A(3)B(3)B(2)B(1)) and crossed dependencies (A(1)A(2)A(3)B(1)B(2)B(3)), containing either three or two dependencies. Both reaction times and prediction errors highlighted problems with processing the middle dependency in nested structures (A(1)A(2)A(3)B(3)_B(1)), reminiscent of the 'missing-verb effect' observed in English and French, but not with crossed structures (A(1)A(2)A(3)B(1)_B(3)). Prior linguistic experience did not play a major role: native speakers of German and Dutch-which permit nested and crossed dependencies, respectively-showed a similar pattern of results for sequences with three dependencies. As for sequences with two dependencies, reaction times and prediction errors were similar for both nested and crossed dependencies. The results suggest that constraints on the processing of multiple non-adjacent dependencies are determined by the specific ordering of the non-adjacent dependencies (i.e. nested or crossed), as well as the number of non-adjacent dependencies to be resolved (i.e. two or three). Furthermore, these constraints may not be specific to language but instead derive from limitations on structured sequence learning.

  15. 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

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

    PubMed

    Senter, Phil; 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.

  17. Fouling assemblages on offshore wind power plants and adjacent substrata

    NASA Astrophysics Data System (ADS)

    Wilhelmsson, Dan; Malm, Torleif

    2008-09-01

    A significant expansion of offshore wind power is expected in the near future, with thousands of turbines in coastal waters, and various aspects of how this may influence the coastal ecology including disturbance effects from noise, shadows, electromagnetic fields, and changed hydrological conditions are accordingly of concern. Further, wind power plants constitute habitats for a number of organisms, and may locally alter assemblage composition and biomass of invertebrates, algae and fish. In this study, fouling assemblages on offshore wind turbines were compared to adjacent hard substrate. Influences of the structures on the seabed were also investigated. The turbines differed significantly from adjacent boulders in terms of assemblage composition of epibiota and motile invertebrates. Species number and Shannon-Wiener diversity were, also, significantly lower on the wind power plants. It was also indicated that the turbines might have affected assemblages of invertebrates and algae on adjacent boulders. Off shore wind power plant offer atypical substrates for fouling assemblages in terms of orientation, depth range, structure, and surface texture. Some potential ecological implications of the addition of these non-natural habitats for coastal ecology are discussed.

  18. Structural and mutational analysis of a conserved gene (DGSI) from the minimal DiGeorge syndrome critical region.

    PubMed

    Gong, W; Emanuel, B S; Galili, N; Kim, D H; Roe, B; Driscoll, D A; Budarf, M L

    1997-02-01

    The majority of patients with DiGeorge syndrome (DGS), velocardiofacial syndrome (VCFS), conotruncal anomaly face syndrome (CTAFS) and some individuals with familial or sporadic conotruncal cardiac defects have hemizygous deletions of chromosome 22. Most patients with these disorders share a common large deletion, spanning > 1.5 Mb within 22q11.21-q11.23. Recently, the smallest region of deletion overlap has been narrowed to a 250 kb area, the minimal DGS critical region (MDGCR), which includes the locus D22S75 (N25). We have isolated and characterized a novel, highly conserved gene, DGSI, within the MDGCR. DGSI has 10 exons and nine introns encompassing 1702 bp of cDNA sequence and 11 kb of genomic DNA. The encoded protein has 476 amino acids with a predicted mol. wt of 52.6 kDa. The intron-exon boundaries have been analyzed and conform to the consensus GT/AG motif. The corresponding murine Dgsi has been isolated and localized to proximal mouse chromosome 16. The mouse gene contains the same number of exons and introns, and the predicted protein has 479 amino acids with 93.2% identity to that of the human DGSI gene. By database searching, both genes have significant homology to a Caenorhabditis elegans hypothetical protein, F42H10.7. Further, mutation analysis has been performed in 16 patients, who have no detectable 22q11.2 deletion and some of the characteristic clinical features of DGS/VCFS. We have detected eight sequence variants in DGSI. These occurred in the 5'-untranslated region, the coding region and the intronic regions adjacent to the intron-exon boundaries of the gene. Seven of the eight variants were also present in normal controls or unaffected family members, suggesting they may not be of etiologic significance.

  19. 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.

  20. Critical slowing down exponents in structural glasses: Random orthogonal and related models

    NASA Astrophysics Data System (ADS)

    Caltagirone, F.; Ferrari, U.; Leuzzi, L.; Parisi, G.; Rizzo, T.

    2012-08-01

    An important prediction of mode-coupling theory is the relationship between the power-law decay exponents in the β regime and the consequent definition of the so-called exponent parameter λ. In the context of a certain class of mean-field glass models with quenched disorder, the physical meaning of λ has recently been understood, yielding a method to compute it exactly in a static framework. In this paper we exploit this new technique to compute the critical slowing down exponents for such models including, as special cases, the Sherrington-Kirkpatrick model, the p-spin model, and the random orthogonal model.

  1. Self-organized criticality and coevolution of network structure and dynamics.

    PubMed

    Fronczak, Piotr; Fronczak, Agata; Hołyst, Janusz A

    2006-04-01

    We investigate, by numerical simulations, how the avalanche dynamics of the Bak-Tang-Wiesenfeld sandpile model can induce emergence of scale-free networks and how this emerging structure affects dynamics of the system.

  2. The effect of mesenchymal stem cell sheets on structural allograft healing of critical sized femoral defects in mice.

    PubMed

    Long, Teng; Zhu, Zhenan; Awad, Hani A; Schwarz, Edward M; Hilton, Matthew J; Dong, Yufeng

    2014-03-01

    Structural bone allografts are widely used in the clinic to treat critical sized bone defects, despite lacking the osteoinductive characteristics of live autografts. To address this, we generated revitalized structural allografts wrapped with mesenchymal stem/progenitor cell (MSC) sheets, which were produced by expanding primary syngenic bone marrow derived cells on temperature-responsive plates, as a tissue-engineered periosteum. In vitro assays demonstrated maintenance of the MSC phenotype in the sheets, suggesting that short-term culturing of MSC sheets is not detrimental. To test their efficacy in vivo, allografts wrapped with MSC sheets were transplanted into 4-mm murine femoral defects and compared to allografts with direct seeding of MSCs and allografts without cells. Evaluations consisted of X-ray plain radiography, 3D microCT, histology, and biomechanical testing at 4- and 6-weeks post-surgery. Our findings demonstrate that MSC sheets induce prolonged cartilage formation at the graft-host junction and enhanced bone callus formation, as well as graft-host osteointegration. Moreover, a large periosteal callus was observed spanning the allografts with MSC sheets, which partially mimics live autograft healing. Finally, biomechanical testing showed a significant increase in the structural and functional properties of MSC sheet grafted femurs. Taken together, MSC sheets exhibit enhanced osteogenicity during critical sized bone defect repair, demonstrating the feasibility of this tissue engineering solution for massive allograft healing.

  3. Low genetic diversity and strong population structure shaped by anthropogenic habitat fragmentation in a critically endangered primate, Trachypithecus leucocephalus.

    PubMed

    Wang, W; Qiao, Y; Li, S; Pan, W; Yao, M

    2017-02-15

    Habitat fragmentation may strongly impact population genetic structure and reduce the genetic diversity and viability of small and isolated populations. The white-headed langur (Trachypithecus leucocephalus) is a critically endangered primate species living in a highly fragmented and human-modified habitat in southern China. We examined the population genetic structure and genetic diversity of the species and investigated the environmental and anthropogenic factors that may have shaped its population structure. We used 214 unique multi-locus genotypes from 41 social groups across the main distribution area of T. leucocephalus, and found strong genetic structure and significant genetic differentiation among local populations. Our landscape genetic analyses using a causal modelling framework suggest that a large habitat gap and geographical distance represent the primary landscape elements shaping genetic structure, yet high levels of genetic differentiation also exist between patches separated by a small habitat gap or road. This is the first comprehensive study that has evaluated the population genetic structure and diversity of T. leucocephalus using nuclear markers. Our results indicate strong negative impacts of anthropogenic land modifications and habitat fragmentation on primate genetic connectivity between forest patches. Our analyses suggest that two management units of the species could be defined, and indicate that habitat continuity should be enforced and restored to reduce genetic isolation and enhance population viability.Heredity advance online publication, 15 February 2017; doi:10.1038/hdy.2017.2.

  4. Origami structures with a critical transition to bistability arising from hidden degrees of freedom

    NASA Astrophysics Data System (ADS)

    Silverberg, Jesse L.; Na, Jun-Hee; Evans, Arthur A.; Liu, Bin; Hull, Thomas C.; Santangelo, Christian D.; Lang, Robert J.; Hayward, Ryan C.; Cohen, Itai

    2015-04-01

    Origami is used beyond purely aesthetic pursuits to design responsive and customizable mechanical metamaterials. However, a generalized physical understanding of origami remains elusive, owing to the challenge of determining whether local kinematic constraints are globally compatible and to an incomplete understanding of how the folded sheet’s material properties contribute to the overall mechanical response. Here, we show that the traditional square twist, whose crease pattern has zero degrees of freedom (DOF) and therefore should not be foldable, can nevertheless be folded by accessing bending deformations that are not explicit in the crease pattern. These hidden bending DOF are separated from the crease DOF by an energy gap that gives rise to a geometrically driven critical bifurcation between mono- and bistability. Noting its potential utility for fabricating mechanical switches, we use a temperature-responsive polymer-gel version of the square twist to demonstrate hysteretic folding dynamics at the sub-millimetre scale.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Critical State Finite Element Models of Contractional Fault-Related Folding: Structural and Mechanical Analyses

    NASA Astrophysics Data System (ADS)

    Albertz, M.; Lingrey, S.; Sanz, P. F.

    2011-12-01

    Geometric/kinematic models of the common fault-related fold types (fault-bend, fault-propagation, detachment folding) typically assume a simplified flexural-slip based bed-parallel simple shear mechanism. The magnitude of local strain is a function of layer dip change irrespective of material properties. Line-lengths parallel to and layer thicknesses orthogonal to the flexural-slip surface remain constant. This study reports on a range of more complicated kinematic and mechanical responses observed in fourteen idealized forward numerical models of contractional fault-related folding. The models test the effects of material properties, initial fault dip, and the presence of weak inter-layer detachment horizons. We employ a Lagrangian finite element method with adaptive remeshing and a constitutive model that is based on critical state mechanics. This approach allows for large, volumetric deformation and realistic evolution of the failure envelope during progressive deformation. We demonstrate that material properties affect the way faults propagate and thus exert a significant control on resultant fold layer geometry. In most cases, these geometries differ from the flexural-slip based kinematic idealizations. For instance, models of uniform sandstone properties exhibit efficient strain localization and clear patterns of fault tip propagation. Uniform shale properties tends to inhibit fault propagation due to distributed plastic deformation. Models with mixed inter-layered sandstone and shale deform in a disharmonic manner, resembling lobate-cuspate arrangements that are common to many outcrop-scale folds. Inter-layer detachments accommodate shortening by bed-parallel slip, resulting in fault-bend fold kinematics, imbrication of sand layers, and a general absence of fault propagation across layers. Constant area based plane strain restoration of the deformed models recovers the first-order contractional deformation (80-90% of true contractional strain). Constant line

  10. Structure of fluctuations near mean-field critical points and spinodals and its implication for physical processes.

    PubMed

    Klein, W; Gould, Harvey; Gulbahce, Natali; Rundle, J B; Tiampo, K

    2007-03-01

    We analyze the structure of fluctuations near critical points and spinodals in mean-field and near-mean-field systems. Unlike systems that are non-mean-field, for which a fluctuation can be represented by a single cluster in a properly chosen percolation model, a fluctuation in mean-field and near-mean-field systems consists of a large number of clusters, which we term fundamental clusters. The structure of the latter and the way that they form fluctuations has important physical consequences for phenomena as diverse as nucleation in supercooled liquids, spinodal decomposition and continuous ordering, and the statistical distribution of earthquakes. The effects due to the fundamental clusters implies that they are physical objects and not only mathematical constructs.

  11. High Resolution Three-Dimensional MR Imaging of the Skull Base: Compartments, Boundaries, and Critical Structures.

    PubMed

    Blitz, Ari Meir; Aygun, Nafi; Herzka, Daniel A; Ishii, Masaru; Gallia, Gary L

    2017-01-01

    High-resolution 3D MRI of the skull base allows for a more detailed and accurate assessment of normal anatomic structures as well as the location and extent of skull base pathologies than has previously been possible. This article describes the techniques employed for high-resolution skull base MRI including pre- and post-contrast constructive interference in the steady state (CISS) imaging and their utility for evaluation of the many small structures of the skull base, focusing on those regions and concepts most pertinent to localization of cranial nerve palsies and in providing pre-operative guidance and post-operative assessment. The concept of skull base compartments as a means of conceptualizing the various layers of the skull base and their importance in assessment of masses of the skull base is discussed.

  12. 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.

  13. Critical transition to bistability arising from hidden degrees of freedom in origami structures

    NASA Astrophysics Data System (ADS)

    Cohen, Itai; Silverberg, Jesse; Na, Jun-Hee; Evans, Arthur; Liu, Bin; Hull, Thomas; Santangelo, Christian; Lang, Robert; Hayward, Ryan

    2015-03-01

    Origami, the traditional art of paper folding, is now being used to design responsive, dynamic, and customizable mechanical metamaterials. The remarkable abilities of these origami-inspired devices emerge from a predefined crease pattern, which couples kinematic folding constraints to the geometric placement of creases. In spite of this progress, a generalized physical understanding of origami remains elusive due to the challenge in determining whether local kinematic constraints are globally compatible, and an incomplete understanding of how bending and crease plasticity found in real materials contribute to the overall mechanical response. Here, we show experimentally and theoretically that the traditional square twist, whose crease pattern has zero degrees of freedom (DOF) and therefore should not be foldable, is nevertheless able to be folded by accessing higher energy scale deformations associated with bending. Due to the separation of bending and crease energy scales, these hidden DOF lead to a geometrically-driven critical bifurcation between mono- and bistability. The scale-free geometric underpinnings of this physical phenomenon suggest a generalized design principle that can be useful for fabricating micro- and nanoscale mechanical switches.

  14. Adhesion to tooth structure: a critical review of "micro" bond strength test methods.

    PubMed

    Armstrong, Steve; Geraldeli, Saulo; Maia, Rodrigo; Raposo, Luís Henrique Araújo; Soares, Carlos José; Yamagawa, Junichiro

    2010-02-01

    The objective of this paper is to critically review the literature regarding the mechanics, geometry, load application and other testing parameters of "micro" shear and tensile adhesion tests, and to outline their advantages and limitations. The testing of multiple specimens from a single tooth conserves teeth and allows research designs not possible using conventional 'macro' methods. Specimen fabrication, gripping and load application methods, in addition to material properties of the various components comprising the resin-tooth adhesive bond, will influence the stress distribution and consequently, the nominal bond strength and failure mode. These issues must be understood; as should the limitations inherent to strength-based testing of a complicated adhesive bond joining dissimilar substrates, for proper test selection, conduct and interpretation. Finite element analysis and comprehensive reporting of test conduct and results will further our efforts towards a standardization of test procedures. For the foreseeable future, both "micro" and "macro" bond strength tests will, as well as various morphological and spectroscopic investigative techniques, continue to be important tools for improving resin-tooth adhesion to increase the service life of dental resin-based composite restorations.

  15. A Study of the Dependence of Microsegregation on Critical Solidification Parameters in Rapidly-Quenched Structures.

    DTIC Science & Technology

    1982-01-01

    steel (Refs. 2,3,5), hardfacing on a nickel base superalloy (Refs. 2,3,7) gold on nickel (Ref. 8), and copper-nickel on structural steel (Ref. 9). Addi...34 Hardfacing of Nimonic 75 Using 2 kW Continuous-Wave CO2 Laser", Metals Tech., June 1980, p 232. 8. C. W. Draper and L. S. Meyer, "Laser Surface Alloying of

  16. Age structure is critical to the population dynamics and survival of honeybee colonies

    PubMed Central

    Betti, M. I.; Wahl, L. M.

    2016-01-01

    Age structure is an important feature of the division of labour within honeybee colonies, but its effects on colony dynamics have rarely been explored. We present a model of a honeybee colony that incorporates this key feature, and use this model to explore the effects of both winter and disease on the fate of the colony. The model offers a novel explanation for the frequently observed phenomenon of ‘spring dwindle’, which emerges as a natural consequence of the age-structured dynamics. Furthermore, the results indicate that a model taking age structure into account markedly affects the predicted timing and severity of disease within a bee colony. The timing of the onset of disease with respect to the changing seasons may also have a substantial impact on the fate of a honeybee colony. Finally, simulations predict that an infection may persist in a honeybee colony over several years, with effects that compound over time. Thus, the ultimate collapse of the colony may be the result of events several years past. PMID:28018627

  17. 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.

  18. 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

  19. 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.

  20. Highly Critical Exchange of Primary Structure Parts at the Fully Integrated NIRSpec-Instrument for JWST

    NASA Astrophysics Data System (ADS)

    Funke, Matthias; Ehrenwinkler, Ralf; Jentsch, Michael; Jollet, Delphine

    2014-06-01

    As the successor of the Hubble Space Telescope a new spacecraft, the James Webb Space Telescope (JWST), is currently under development at NASA and affiliated partners. One of the ESA contributions to the JWST is the Near Infrared Spectrograph, NIRSpec - capable of high resolution spectroscopy which was developed by Airbus Defence and Space (former Astrium Satellites) under contract of ESA.This paper deals with the challenge of replacing elements in the primary structural load path without violating the achieved high precision alignment of the fully integrated instrument.

  1. 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.

  2. Quantum size effect in Pb(100) films: Critical role of crystal band structure

    NASA Astrophysics Data System (ADS)

    Wei, C. M.; Chou, M. Y.

    2007-05-01

    We report first-principles calculations of Pb(100) films up to 22 monolayers to study variations in the surface energy and work function as a function of film thickness. An even-odd oscillation is found in these two quantities, while a jelliumlike model for this s-p metal predicts a periodicity of about three monolayers. This unexpected result is explained by considering a coherent superposition of contributions from quantum-well states centered at both the Γ¯ and Mmacr points in the two-dimensional Brillouin zone, demonstrating the importance of crystal band structure in studying the quantum size effect in metal thin films.

  3. 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.

  4. Strong spatial genetic structure reduces reproductive success in the critically endangered plant genus Pseudomisopates.

    PubMed

    Amat, María E; Silvertown, Jonathan; Vargas, Pablo

    2013-01-01

    Clonal growth can be a double-edged sword for endangered species, because the short-term insurance against extinction may incur a longer-term hazard of creating small inbred populations with low fecundity. In the present study, we quantify the advantages and disadvantages of clonal growth regarding the fitness of the central Iberian monotypic endangered genus Pseudomisopates. Preliminary studies showed that the species is self-incompatible and exhibits extensive clonal growth with plants flowering profusely. However, seeds at many sites seemed to be unviable, and no seedlings have been observed in the field. A fully replicated nested sampling design (n = 100) was conducted to explore genetic (using seven SSR loci) and environmental factors potentially affecting seed viability, such as: 1) clonal and genetic diversity, 2) spatial genetic structure, and 3) environmental factors (shrub cover and grazing). Generalized Linear Mixed Models were fitted relating genetic and environmental variables to reproductive variables (seed viability and flower display). Our results indicate that the relatively low genotypic diversity of the population (PD = 0.23), as quantified by SSRs, and the strong spatial genetic structure observed are congruent with intense clonal growth. This clonal growth is enhanced by unfavorable environmental conditions, such as canopy closure and grazing. Under these circumstances, both flower display and mate availability decrease, thus hindering sexual reproduction. Indeed, a mixed reproductive system (clonal and sexual) to escape environmental stochasticity is crucial for the survival of Pseudomisopates, a species inhabiting a disturbance-prone ecosystem.

  5. Critical role of tedizolid in the treatment of acute bacterial skin and skin structure infections

    PubMed Central

    Ferrández, Olivia; Urbina, Olatz; Grau, Santiago

    2017-01-01

    Tedizolid phosphate has high activity against the Gram-positive microorganisms mainly involved in acute bacterial skin and skin structure infections, such as strains of Staphylococcus aureus (including methicillin-resistant S. aureus strains and methicillin-sensitive S. aureus strains), Streptococcus pyogenes, Streptococcus agalactiae, the Streptococcus anginosus group, and Enterococcus faecalis, including those with some mechanism of resistance limiting the use of linezolid. The area under the curve for time 0–24 hours/minimum inhibitory concentration (MIC) pharmacodynamic ratio has shown the best correlation with the efficacy of tedizolid, versus the time above MIC ratio and the maximum drug concentration/minimum inhibitory concentration ratio. Administration of this antibiotic for 6 days has shown its noninferiority versus administration of linezolid for 10 days in patients with skin and skin structure infections enrolled in two Phase III studies (ESTABLISH-1 and ESTABLISH-2). Tedizolid’s more favorable safety profile and dosage regimen, which allow once-daily administration, versus linezolid, position it as a good therapeutic alternative. However, whether or not the greater economic cost associated with this antibiotic is offset by its shorter treatment duration and possibility of oral administration in routine clinical practice has yet to be clarified. PMID:28053508

  6. 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.

  7. Crystal structure of CCM3, a cerebral cavernous malformation protein critical for vascular integrity.

    PubMed

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

    2010-07-30

    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 A 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.

  8. Nucleotide binding domains of human CFTR: a structural classification of critical residues and disease-causing mutations.

    PubMed

    Eudes, R; Lehn, P; Férec, C; Mornon, J-P; Callebaut, I

    2005-09-01

    Defective function of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) causes CF, the most frequent lethal inherited disease among the Caucasian population. The structure of this chloride ion channel includes two nucleotide-binding domains (NBDs), whose ATPase activity controls channel gating. Recently, the experimental structures of mouse and human CFTR NBD1 and our model of the human CFTR NBD1/NBD2 heterodimer have provided new insights into specific structural features of the CFTR NBD dimer. In the present work, we provide a structural classification of CF-causing mutations which may complement the existing functional classification. Our analysis also identified amino acid residues which may play a critical role in interdomain interaction and are located at the NBD1-NBD2 interface or on the surface of the dimer. In particular, a cluster of aromatic amino acids, which includes F508 and straddles the two NBDs, might be directly involved in the interaction of the NBD1/NBD2 heterodimer with the channel-forming membrane-spanning domains.

  9. A substrate-bound structure of cyanobacterial biliverdin reductase identifies stacked substrates as critical for activity

    PubMed Central

    Takao, Haruna; Hirabayashi, Kei; Nishigaya, Yuki; Kouriki, Haruna; Nakaniwa, Tetsuko; Hagiwara, Yoshinori; Harada, Jiro; Sato, Hideaki; Yamazaki, Toshimasa; Sakakibara, Yoichi; Suiko, Masahito; Asada, Yujiro; Takahashi, Yasuhiro; Yamamoto, Ken; Fukuyama, Keiichi; Sugishima, Masakazu; Wada, Kei

    2017-01-01

    Biliverdin reductase catalyses the last step in haem degradation and produces the major lipophilic antioxidant bilirubin via reduction of biliverdin, using NAD(P)H as a cofactor. Despite the importance of biliverdin reductase in maintaining the redox balance, the molecular details of the reaction it catalyses remain unknown. Here we present the crystal structure of biliverdin reductase in complex with biliverdin and NADP+. Unexpectedly, two biliverdin molecules, which we designated the proximal and distal biliverdins, bind with stacked geometry in the active site. The nicotinamide ring of the NADP+ is located close to the reaction site on the proximal biliverdin, supporting that the hydride directly attacks this position of the proximal biliverdin. The results of mutagenesis studies suggest that a conserved Arg185 is essential for the catalysis. The distal biliverdin probably acts as a conduit to deliver the proton from Arg185 to the proximal biliverdin, thus yielding bilirubin. PMID:28169272

  10. 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.

  11. Measurement of Critical Structures around Paraclinoidal Area : A Cadaveric Morphometric Study

    PubMed Central

    Lee, Hyun-Woo; Park, Hyun-Seok; Yoo, Ki-Soo; Kim, Ki-Uk

    2013-01-01

    Objective Although removal of the anterior clinoid process (ACP) is essential surgical technique, studies about quantitative measurements of the space broadening by the anterior clinoidectomy are rare. The purposes of this study are to investigate the dimension of the ACP, to quantify the improved exposure of the parasellar space after extradural anterior clinoidectomy and to measure the correlation of each structure around the paraclinoidal area. Methods Eleven formalin-fixed Korean adult cadaveric heads were used and frontotemporal craniotomies were done bilaterally. The length of C6 segment of the internal carotid artery on its lateral and medial side and optic nerve length were checked before and after anterior clinoidectomy. The basal width and height of the ACP were measured. The relationships among the paraclinoidal structures were assessed. The origin and projection of the ophthalmic artery (OA) were investigated. Results The mean values of intradural basal width and height of the ACP were 10.82 mm and 7.61 mm respectively. The mean length of the C6 lateral and medial side increased 49%. The mean length of optic nerve increased 97%. At the parasellar area, the lengths from the optic strut to the falciform liament, distal dural ring, origin of OA were 6.69 mm, 9.36 mm and 5.99 mm, respectively. The distance between CN III and IV was 11.06 mm. Conclusion With the removal of ACP, exposure of the C6 segments and optic nerve can expand 49% and 97%, respectively. This technique should be among a surgeon's essential skills for treating lesions around the parasellar area. PMID:24044074

  12. Wood production response to climate change will depend critically on forest composition and structure.

    PubMed

    Coomes, David A; Flores, Olivier; Holdaway, Robert; Jucker, Tommaso; Lines, Emily R; Vanderwel, Mark C

    2014-12-01

    Established forests currently function as a major carbon sink, sequestering as woody biomass about 26% of global fossil fuel emissions. Whether forests continue to act as a global sink will depend on many factors, including the response of aboveground wood production (AWP; MgC ha(-1 ) yr(-1) ) to climate change. Here, we explore how AWP in New Zealand's natural forests is likely to change. We start by statistically modelling the present-day growth of 97 199 individual trees within 1070 permanently marked inventory plots as a function of tree size, competitive neighbourhood and climate. We then use these growth models to identify the factors that most influence present-day AWP and to predict responses to medium-term climate change under different assumptions. We find that if the composition and structure of New Zealand's forests were to remain unchanged over the next 30 years, then AWP would increase by 6-23%, primarily as a result of physiological responses to warmer temperatures (with no appreciable effect of changing rainfall). However, if warmth-requiring trees were able to migrate into currently cooler areas and if denser canopies were able to form, then a different AWP response is likely: forests growing in the cool mountain environments would show a 30% increase in AWP, while those in the lowland would hardly respond (on average, -3% when mean annual temperature exceeds 8.0 °C). We conclude that response of wood production to anthropogenic climate change is not only dependent on the physiological responses of individual trees, but is highly contingent on whether forests adjust in composition and structure.

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

    PubMed

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

    2016-06-10

    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.

  14. 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.

  15. A critical analysis of dipole-moment calculations as obtained from experimental and theoretical structure factors.

    PubMed

    Poulain-Paul, Agnieszka; Nassour, Ayoub; Jelsch, Christian; Guillot, Benoit; Kubicki, Maciej; Lecomte, Claude

    2012-11-01

    Three models of charge-density distribution - Hansen-Coppens multipolar, virtual atom and kappa - of different complexities, different numbers of refined parameters, and with variable levels of restraints, were tested against theoretical and high-resolution X-ray diffraction structure factors for 2-methyl-4-nitro-1-phenyl-1H-imidazole-5-carbonitrile. The influence of the model, refinement strategy, multipole level and treatment of the H atoms on the dipole moment was investigated. The dipole moment turned out to be very sensitive to the refinement strategy. Also, small changes in H-atom treatment can greatly influence the calculated magnitude and orientation of the dipole moment. The best results were obtained when H atoms were kept in positions determined by neutron diffraction and anisotropic displacement parameters (obtained by SHADE, in this case) were used. Also, constraints on kappa values of H atoms were found to be superior to the free refinement of these parameters. It is also shown that the over-parametrization of the multipolar model, although possibly leading to better residuals, in general gives worse dipole moments.

  16. A Passage into Critical Theory.

    ERIC Educational Resources Information Center

    Lynn, Steven

    1990-01-01

    Shows how a single passage might be handled by New Criticism, structuralism, deconstructionism, psychological criticism, and feminist criticism. Concludes that a plurality of critical approaches is better than a unity of approach. (RS)

  17. Adjacent-level arthroplasty following cervical fusion.

    PubMed

    Rajakumar, Deshpande V; Hari, Akshay; Krishna, Murali; Konar, Subhas; Sharma, Ankit

    2017-02-01

    OBJECTIVE Adjacent-level disc degeneration following cervical fusion has been well reported. This condition poses a major treatment dilemma when it becomes symptomatic. The potential application of cervical arthroplasty to preserve motion in the affected segment is not well documented, with few studies in the literature. The authors present their initial experience of analyzing clinical and radiological results in such patients who were treated with arthroplasty for new or persistent arm and/or neck symptoms related to neural compression due to adjacent-segment disease after anterior cervical discectomy and fusion (ACDF). METHODS During a 5-year period, 11 patients who had undergone ACDF anterior cervical discectomy and fusion (ACDF) and subsequently developed recurrent neck or arm pain related to adjacent-level cervical disc disease were treated with cervical arthroplasty at the authors' institution. A total of 15 devices were implanted (range of treated levels per patient: 1-3). Clinical evaluation was performed both before and after surgery, using a visual analog scale (VAS) for pain and the Neck Disability Index (NDI). Radiological outcomes were analyzed using pre- and postoperative flexion/extension lateral radiographs measuring Cobb angle (overall C2-7 sagittal alignment), functional spinal unit (FSU) angle, and range of motion (ROM). RESULTS There were no major perioperative complications or device-related failures. Statistically significant results, obtained in all cases, were reflected by an improvement in VAS scores for neck/arm pain and NDI scores for neck pain. Radiologically, statistically significant increases in the overall lordosis (as measured by Cobb angle) and ROM at the treated disc level were observed. Three patients were lost to follow-up within the first year after arthroplasty. In the remaining 8 cases, the duration of follow-up ranged from 1 to 3 years. None of these 8 patients required surgery for the same vertebral level during the follow

  18. Structural and mechanistic insights into nuclear transport and delivery of the critical pluripotency factor Oct4 to DNA.

    PubMed

    Okuyama, Takahide; Yamagishi, Ryosuke; Shimada, Jiro; Ikeda, Masaaki; Maruoka, Yayoi; Kaneko, Hiroki

    2017-02-06

    Oct4 is a master regulator of the induction and maintenance of cellular pluripotency, and has crucial roles in early stages of differentiation. It is the only factor that cannot be substituted by other members of the same protein family to induce pluripotency. However, although Oct4 nuclear transport and delivery to target DNA are critical events for reprogramming to pluripotency, little is known about the molecular mechanism. Oct4 is imported to the nucleus by the classical nuclear transport mechanism, which requires importin α as an adaptor to bind the nuclear localization signal (NLS). Although there are structures of complexes of the NLS of transcription factors (TFs) in complex with importin α, there are no structures available for complexes involving intact TFs. We have therefore modeled the structure of the complex of the whole Oct4 POU domain and importin α2 using protein-protein docking and molecular dynamics. The model explains how the Ebola virus VP24 protein has a negative effect on the nuclear import of STAT1 by importin α but not on Oct4, and how Nup 50 facilitates cargo release from importin α. The model demonstrates the structural differences between the Oct4 importin α bound and DNA bound crystal states. We propose that the "expanded linker" between the two DNA-binding domains of Oct4 is an intrinsically disordered region and that its conformational changes have a key role in the recognition/binding to both DNA and importin α. Moreover, we propose that this structural change enables efficient delivery to DNA after release from importin α.

  19. 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)

  20. 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

  1. Critical initial smoothness of a two-dimensional interface for well-defined needle-structure growth

    NASA Astrophysics Data System (ADS)

    Mineev, M. B.

    1990-12-01

    Considering two-dimensional evolution of an interface, we identify qualitatively different regimes dependent on the initial smoothenss of the front characterized by the parameter γ that describes how fast an initial Fourier coefficient A0k decreases with k, when k-->∞, where A0k=e-α-βkγ. It is shown that for γ>2, after some time, the front's shape has a starlike well-defined needle structure. The number of needles increases with time, and the needles develop into cusps in finite time. For γ<=2, the starlike symmetry is broken and we have a less regular form. The conclusion is that for an almost flat initial front (α>>1, β<<1) the critical smoothness is γ=2.

  2. 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

    2015-03-06

    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.

  3. 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

  4. 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.

  5. 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.

  6. 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....

  7. 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....

  8. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.404 Signals at adjacent control points. Signals at adjacent controlled... 49 Transportation 4 2011-10-01 2011-10-01 false Signals at adjacent control points....

  9. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.404 Signals at adjacent control points. Signals at adjacent controlled... 49 Transportation 4 2010-10-01 2010-10-01 false Signals at adjacent control points....

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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.

  16. Rap1 in Candida albicans: an Unusual Structural Organization and a Critical Function in Suppressing Telomere Recombination▿

    PubMed Central

    Yu, Eun Young; Yen, Wei-Feng; Steinberg-Neifach, Olga; Lue, Neal F.

    2010-01-01

    Rap1 (repressor activator protein 1) is a conserved multifunctional protein initially identified as a transcriptional regulator of ribosomal protein genes in Saccharomyces cerevisiae but subsequently shown to play diverse functions at multiple chromosomal loci, including telomeres. The function of Rap1 appears to be evolutionarily plastic, especially in the budding yeast lineages. We report here our biochemical and molecular genetic characterizations of Candida albicans Rap1, which exhibits an unusual, miniaturized domain organization in comparison to the S. cerevisiae homologue. We show that in contrast to S. cerevisiae, C. albicans RAP1 is not essential for cell viability but is critical for maintaining normal telomere length and structure. The rap1 null mutant exhibits drastic telomere-length dysregulation and accumulates high levels of telomere circles, which can be largely attributed to aberrant recombination activities at telomeres. Analysis of combination mutants indicates that Rap1 and other telomere proteins mediate overlapping but nonredundant roles in telomere protection. Consistent with the telomere phenotypes of the mutant, C. albicans Rap1 is localized to telomeres in vivo and recognizes the unusual telomere repeat unit with high affinity and sequence specificity in vitro. The DNA-binding Myb domain of C. albicans Rap1 is sufficient to suppress most of the telomere aberrations observed in the null mutant. Notably, we were unable to detect specific binding of C. albicans Rap1 to gene promoters in vivo or in vitro, suggesting that its functions are more circumscribed in this organism. Our findings provide insights on the evolution and mechanistic plasticity of a widely conserved and functionally critical telomere component. PMID:20008550

  17. 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

  18. 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.

  19. Random mutagenesis of yeast 25S rRNA identify bases critical for 60S subunit structural integrity and function

    PubMed Central

    Nemoto, Naoki; Udagawa, Tsuyoshi; Chowdhury, Wasimul; Kitabatake, Makoto; Shin, Byung-shik; Hiraishi, Hiroyuki; Wang, Suzhi; Singh, Chingakham Ranjit; Brown, Susan J.; Ohno, Mutsuhito; Asano, Katsura

    2013-01-01

    In yeast Saccharomyces cerevisiae, 25S rRNA makes up the major mass and shape of the 60S ribosomal subunit. During translation initiation, the 60S subunit joins the 40S initiation complex, producing the 80S initiation complex. During elongation, the 60S subunit binds the CCA-ends of aminoacyl- and peptidyl-tRNAs at the A-loop and P-loop, respectively, transferring the peptide onto the α-amino group of the aminoacyl-tRNA. To study the role of 25S rRNA in translation in vivo, we randomly mutated 25S rRNA and isolated and characterized seven point mutations that affected yeast cell growth and polysome profiles. Four of these mutations, G651A, A1435U, A1446G and A1587G, change a base involved in base triples crucial for structural integrity. Three other mutations change bases near the ribosomal surface: C2879U and U2408C alter the A-loop and P-loop, respectively, and G1735A maps near a Eukarya-specific bridge to the 40S subunit. By polysome profiling in mmslΔ mutants defective in nonfunctional 25S rRNA decay, we show that some of these mutations are defective in both the initiation and elongation phases of translation. Of the mutants characterized, C2879U displays the strongest defect in translation initiation. The ribosome transit-time assay directly shows that this mutation is also defective in peptide elongation/termination. Thus, our genetic analysis not only identifies bases critical for structural integrity of the 60S subunit, but also suggests a role for bases near the peptidyl transferase center in translation initiation. PMID:26824023

  20. 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.

  1. 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.

  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 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.

  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. Strong Coupling Superconductivity in the Vicinity of the Structural Quantum Critical Point in (Ca(x)Sr(1-x))₃Rh₄Sn₁₃.

    PubMed

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

    2015-11-13

    The family of the superconducting quasiskutterudites (Ca(x)Sr(1-x))(3)Rh(4)Sn(13) features a structural quantum critical point at x(c)=0.9, around which a dome-shaped variation of the superconducting transition temperature T(c) is found. Using specific heat, we probe 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 x(c), which we interpret as a result of phonon softening accompanying the structural instability. Furthermore, a remarkably large enhancement of 2Δ/k(B)T(c) and ΔC/γT(c) beyond the Bardeen-Cooper-Schrieffer values is found in the vicinity of the structural quantum critical point. The phase diagram of (Ca(x)Sr(1-x))(3)Rh(4)Sn(13) thus provides a model system to study the interplay between structural quantum criticality and strong electron-phonon coupling superconductivity.

  5. 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

  6. SU-F-BRD-14: Dose Weighted Linear Energy Transfer Analysis of Critical Structures in Proton Therapy of Pediatric Brain Tumor Patients

    SciTech Connect

    Pirlepesov, F.; Shin, J.; Moskvin, V. P.; Gray, J.; Hua, C.; Gajjar, A.; Krasin, M. J.; Merchant, T. E.; Farr, J. B.; Li, Z.

    2015-06-15

    Purpose: Dose weighted Linear Energy Transfer (LETd) analysis of critical structures may be useful in understanding the side effects of the proton therapy. The objective is to analyze the differences between LETd and dose distributions in brain tumor patients receiving double scattering proton therapy, to quantify LETd variation in critical organs, and to identify beam arrangements contributing to high LETd in critical organs. Methods: Monte Carlo simulations of 9 pediatric brain tumor patients were performed. The treatment plans were reconstructed with the TOPAS Monte Carlo code to calculate LETd and dose. The beam data were reconstructed proximal to the aperture of the double scattering nozzle. The dose and LETd to target and critical organs including brain stem, optic chiasm, lens, optic nerve, pituitary gland, and hypothalamus were computed for each beam. Results: Greater variability in LETd compared to dose was observed in the brainstem for patients with a variety of tumor types including 5 patients with tumors located in the posterior fossa. Approximately 20%–44% brainstem volume received LETd of 5kev/µm or greater from beams within gantry angles 180°±30° for 5 patients treated with a 3 beam arrangement. Critical organs received higher LETd when located in the vicinity of the beam distal edge. Conclusion: This study presents a novel strategy in the evaluation of the proton treatment impact on critical organs. While the dose to critical organs is confined below the required limits, the LETd may have significant variation. Critical organs in the vicinity of beam distal edge receive higher LETd and depended on beam arrangement, e.g. in posterior fossa tumor treatment, brainstem receive higher LETd from posterior-anterior beams. This study shows importance of the LETd analysis of the radiation impact on the critical organs in proton therapy and may be used to explain clinical imaging observations after therapy.

  7. Crystal Structure of Vaccinia Viral A27 Protein Reveals a Novel Structure Critical for Its Function and Complex Formation with A26 Protein

    PubMed Central

    Hsieh, Fu-Lien; Ko, Tzu-Ping; Lin, Cheng-Tse; Ho, Meng-Ru; Wang, Iren; Hsu, Shang-Te Danny; Guo, Rey-Ting; Chang, Wen; Wang, Andrew H. J.

    2013-01-01

    Vaccinia virus envelope protein A27 has multiple functions and is conserved in the Orthopoxvirus genus of the poxvirus family. A27 protein binds to cell surface heparan sulfate, provides an anchor for A26 protein packaging into mature virions, and is essential for egress of mature virus (MV) from infected cells. Here, we crystallized and determined the structure of a truncated form of A27 containing amino acids 21–84, C71/72A (tA27) at 2.2 Å resolution. tA27 protein uses the N-terminal region interface (NTR) to form an unexpected trimeric assembly as the basic unit, which contains two parallel α-helices and one unusual antiparallel α-helix; in a serpentine way, two trimers stack with each other to form a hexamer using the C-terminal region interface (CTR). Recombinant tA27 protein forms oligomers in a concentration-dependent manner in vitro in gel filtration. Analytical ultracentrifugation and multi-angle light scattering revealed that tA27 dimerized in solution and that Leu47, Leu51, and Leu54 at the NTR and Ile68, Asn75, and Leu82 at the CTR are responsible for tA27 self-assembly in vitro. Finally, we constructed recombinant vaccinia viruses expressing full length mutant A27 protein defective in either NTR, CTR, or both interactions; the results demonstrated that wild type A27 dimer/trimer formation was impaired in NTR and CTR mutant viruses, resulting in small plaques that are defective in MV egress. Furthermore, the ability of A27 protein to form disulfide-linked protein complexes with A26 protein was partially or completely interrupted by NTR and CTR mutations, resulting in mature virion progeny with increased plasma membrane fusion activity upon cell entry. Together, these results demonstrate that A27 protein trimer structure is critical for MV egress and membrane fusion modulation. Because A27 is a neutralizing target, structural information will aid the development of inhibitors to block A27 self-assembly or complex formation against vaccinia virus

  8. 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…

  9. 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

  10. A Study of the Pronunciation of Words Containing Adjacent Vowels.

    ERIC Educational Resources Information Center

    Greif, Ivo P.

    To determine the usefulness of the commonly taught phonics rule, "only pronounce the first vowel in words that contain adjacent vowels" (the VV rule, with the first "v" pronounced with the long vowel sound), two new studies applied it to words with adjacent vowels in several lists and dictionaries. The first study analyzed words containing…

  11. 47 CFR 90.221 - Adjacent channel power limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Adjacent channel power limits. 90.221 Section 90.221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.221 Adjacent channel...

  12. 47 CFR 90.221 - Adjacent channel power limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Adjacent channel power limits. 90.221 Section 90.221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.221 Adjacent channel...

  13. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  14. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  15. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  16. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  17. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  18. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  19. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  20. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  1. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  2. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  3. Varied interactions between proviruses and adjacent host chromatin.

    PubMed Central

    Conklin, K F; Groudine, M

    1986-01-01

    Retroviruses integrated at unique locations in the host genome can be expressed at different levels. We have analyzed the preintegration sites of three transcriptionally competent avian endogenous proviruses (evs) to determine whether the various levels of provirus expression correlate with their location in active or inactive regions of chromatin. Our results show that in three of four cell types, the chromatin conformation (as defined by relative nuclease sensitivity) of virus preintegration sites correlates with the level of expression of the resident provirus in ev+ cells: two inactive proviruses (ev-1 and ev-2) reside in nuclease-resistant chromatin domains and one active provirus (ev-3) resides in a nuclease-sensitive domain. Nuclear runoff transcription assays reveal that the preintegration sites of the active and inactive viruses are not transcribed. However, in erythrocytes of 15-day-old chicken embryos (15d RBCs), the structure and activity of the ev-3 provirus is independent of the conformation of its preintegration site. In this cell type, the ev-3 preintegration site is organized in a nuclease-resistant conformation, while the ev-3 provirus is in a nuclease-sensitive conformation and is transcribed. In addition, the nuclease sensitivity of host sequences adjacent to ev-3 is altered in ev-3+ 15d RBCs relative to that found in 15d RBCs that lack ev-3. These data suggest that the relationship between preintegration site structure and retrovirus expression is more complex than previously described. Images PMID:3025623

  4. 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.

  5. 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).

  6. Dynamic structure factor of density fluctuations from direct imaging very near (both above and below) the critical point of SF(6).

    PubMed

    Oprisan, Ana; Oprisan, Sorinel A; Bayley, Brittany; Hegseth, John J; Garrabos, Yves; Lecoutre-Chabot, Carole; Beysens, Daniel

    2012-12-01

    Large density fluctuations were observed by illuminating a cylindrical cell filled with sulfur hexafluoride (SF(6)), very near its liquid-gas critical point (|T-T(c)|< 300 μK) and recorded using a microscope with 3 μm spatial resolution. Using a dynamic structure factor algorithm, we determined from the recorded images the structure factor (SF), which measures the spatial distribution of fluctuations at different moments, and the correlation time of fluctuations. This method authorizes local measurements in contrast to the classical scattering techniques that average fluctuations over the illuminating beam. We found that during the very early stages of phase separation the SF scales with the wave vector q according to the Lorentzian q(-2), which shows that the liquid and vapor domains are just emerging. The critical wave number, which is related to the characteristic length of fluctuations, steadily decreases over time, supporting a sustained increase in the spatial scale of the fluctuating domains. The scaled evolution of the critical wave number obeys the universal evolution for the interconnected domains at high volume fraction with an apparent power law exponent of -0.35 ± 0.02. We also determined the correlation time of the fluctuations and inferred values for thermal diffusivity coefficient very near the critical point, above and below. The values were used to pinpoint the crossing of T(c) within 13 μK.

  7. Blind testing cross-linking/mass spectrometry under the auspices of the 11th critical assessment of methods of protein structure prediction (CASP11)

    PubMed Central

    2016-01-01

    Determining the structure of a protein by any method requires various contributions from experimental and computational sides. In a recent study, high-density cross-linking/mass spectrometry (HD-CLMS) data in combination with ab initio structure prediction determined the structure of human serum albumin (HSA) domains, with an RMSD to X-ray structure of up to 2.5 Å, or 3.4 Å in the context of blood serum. This paper reports the blind test on the readiness of this technology through the help of Critical Assessment of protein Structure Prediction (CASP). We identified between 201-381 unique residue pairs at an estimated 5% FDR (at link level albeit with missing site assignment precision evaluation), for four target proteins. HD-CLMS proved reliable once crystal structures were released. However, improvements in structure prediction using cross-link data were slight. We identified two reasons for this. Spread of cross-links along the protein sequence and the tightness of the spatial constraints must be improved. However, for the selected targets even ideal contact data derived from crystal structures did not allow modellers to arrive at the observed structure. Consequently, the progress of HD-CLMS in conjunction with computational modeling methods as a structure determination method, depends on advances on both arms of this hybrid approach. PMID:28317030

  8. 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.

  9. 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.

  10. PIXE analysis of elements in gastric cancer and adjacent mucosa

    NASA Astrophysics Data System (ADS)

    Liu, Qixin; Zhong, Ming; Zhang, Xiaofeng; Yan, Lingnuo; Xu, Yongling; Ye, Simao

    1990-04-01

    The elemental regional distributions in 20 resected human stomach tissues were obtained using PIXE analysis. The samples were pathologically divided into four types: normal, adjacent mucosa A, adjacent mucosa B and cancer. The targets for PIXE analysis were prepared by wet digestion with a pressure bomb system. P, K, Fe, Cu, Zn and Se were measured and statistically analysed. We found significantly higher concentrations of P, K, Cu, Zn and a higher ratio of Cu compared to Zn in cancer tissue as compared with normal tissue, but statistically no significant difference between adjacent mucosa and cancer tissue was found.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. SU-E-T-170: Characterization of the Location, Extent, and Proximity to Critical Structures of Target Volumes Provides Detail for Improved Outcome Predictions Among Pancreatic Cancer Patients

    SciTech Connect

    Cheng, Z; Moore, J; Rosati, L; Mian, O; Narang, A; Herman, J; McNutt, T

    2015-06-15

    Purpose: In radiotherapy, size, location and proximity of the target to critical structures influence treatment decisions. It has been shown that proximity of the target predicts dosimetric sparing of critical structures. In addition to dosimetry, precise location of disease has further implications such as tumor invasion, or proximity to major arteries that inhibit surgery. Knowledge of which patients can be converted to surgical candidates by radiation may have high impact on future treat/no-treat decisions. We propose a method to improve our characterization of the location of pancreatic cancer and treatment volume extent with respect to nearby arteries with the goal of developing features to improve clinical predictions and decisions. Methods: Oncospace is a local learning health system that systematically captures clinical outcomes and all aspects of radiotherapy treatment plans, including overlap volume histograms (OVH) – a measure of spatial relationships between two structures. Minimum and maximum distances of PTV and OARs based on OVH, PTV volume, anatomic location by ICD-9 code, and surgical outcome were queried. Normalized distance to center from the left and right kidney was calculated to indicate tumor location and laterality. Distance to critical arteries (celiac, superior mesenteric, common hepatic) is validated by surgical status (borderline resectable, locally advanced converted to resectable). Results: There were 205 pancreas stereotactic body radiotherapy patients treated from 2009–2015 queried. Location/laterality of tumor based on kidney OVH show strong trends between location by OVH and by ICD-9. Compared to the locally advanced group, the borderline resectable group showed larger geometrical distance from critical arteries (p=0.03). Conclusion: Our platform enabled analysis of shape/size-location relationships. These data suggest that PTV volume and attention to distance between PTVs and surrounding OARs and major arteries may be

  16. 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].

  17. Overall view of tower and adjacent aircraft shelters on flight ...

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

    Overall view of tower and adjacent aircraft shelters on flight line. View to east. - Plattsburgh Air Force Base, Security Guard Tower, Florida Street at Aircraft Shelters Area, Plattsburgh, Clinton County, NY

  18. 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

  19. 10. View north from the adjacent B & O railroad ...

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

    10. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  20. 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

  1. 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

  2. 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

  3. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, ...

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

    VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING SOUTH. GARAGE TO EXTREME LEFT, BUILDING 1 TO EXTREME RIGHT. - Techwood Homes, Building No. 16, 488-514 Techwood Drive, Atlanta, Fulton County, GA

  4. View from water showing south facade and adjacent boat slips ...

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

    View from water showing south facade and adjacent boat slips (Facility Nos. S375 & S376) - U.S. Naval Base, Pearl Harbor, Boat House, Hornet Avenue at Independence Street, Pearl City, Honolulu County, HI

  5. Cement Leakage into Adjacent Vertebral Body Following Percutaneous Vertebroplasty.

    PubMed

    Park, Jae Hoo; Kim, Hyeun Sung; Kim, Seok Won

    2016-06-01

    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.

  6. 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

  7. Basement, room 23, looking southwest into two adjacent offices with ...

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

    Basement, room 23, looking southwest into two adjacent offices with soundproof walls and pedestal flooring - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOME, ...

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

    VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOME, LOOKING WEST. GEORGIA TECH DORMITORY BUILDING, 581-587 TECHWOOD DRIVE, IN FOREGROUND. - Techwood Homes, Building No. 16, 488-514 Techwood Drive, Atlanta, Fulton County, GA

  19. 72. View of reservoir adjacent to south wall of blowing ...

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

    72. View of reservoir adjacent to south wall of blowing engine house where water from furnaces was allowed to cool. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  20. 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…

  1. 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…

  2. Metal content of biopsies adjacent to dental cast alloys.

    PubMed

    Garhammer, Pauline; Schmalz, G; Hiller, K-A; Reitinger, T

    2003-06-01

    Single case reports indicate that components of dental alloys accumulate in the adjacent soft tissue of the oral cavity. However, data on a wider range of dental alloys and patient groups are scarce. Therefore, the aim of the present study was to examine the metal content of oral tissues adjacent to dental alloys showing persisting signs of inflammation or other discoloration (affected sites) and of healthy control sites with no adjacent metal restoration in 28 patients. The composition of the adjacent alloys was analyzed and compared to the alloy components in the affected sites. Tissue analysis was performed using atomic absorption spectroscopy. Alloy analysis was performed with energy-dispersive X-ray analysis. In the affected sites, the metals Ag, Au, Cu, and Pd prevailed compared to control sites, reflecting the frequency distribution of single metals in the adjacent alloys. In most cases (84%), at least one of the analyzed metals was a component of the alloy and also detected in the tissue. Metal components from almost all dental cast alloys can be detected in adjacent tissue.

  3. 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.

  4. Mitotic cells form actin-based bridges with adjacent cells to provide intercellular communication during rounding.

    PubMed

    Fykerud, Tone A; Knudsen, Lars M; Totland, Max Z; Sørensen, Vigdis; Dahal-Koirala, Shiva; Lothe, Ragnhild A; Brech, Andreas; Leithe, Edward

    2016-11-01

    In order to achieve accurate chromosome segregation, eukaryotic cells undergo a dramatic change in morphology to obtain a spherical shape during mitosis. Interphase cells communicate directly with each other by exchanging ions and small molecules via gap junctions, which have important roles in controlling cell growth and differentiation. As cells round up during mitosis, the gap junctional communication between mitotic cells and adjacent interphase cells ceases. Whether mitotic cells use alternative mechanisms for mediating direct cell-cell communication during rounding is currently unknown. Here, we have studied the mechanisms involved in the remodeling of gap junctions during mitosis. We further demonstrate that mitotic cells are able to form actin-based plasma membrane bridges with adjacent cells during rounding. These structures, termed "mitotic nanotubes," were found to be involved in mediating the transport of cytoplasm, including Rab11-positive vesicles, between mitotic cells and adjacent cells. Moreover, a subpool of the gap-junction channel protein connexin43 localized in these intercellular bridges during mitosis. Collectively, the data provide new insights into the mechanisms involved in the remodeling of gap junctions during mitosis and identify actin-based plasma membrane bridges as a novel means of communication between mitotic cells and adjacent cells during rounding.

  5. Mitotic cells form actin-based bridges with adjacent cells to provide intercellular communication during rounding

    PubMed Central

    Fykerud, Tone A.; Knudsen, Lars M.; Totland, Max Z.; Dahal-Koirala, Shiva; Lothe, Ragnhild A.; Brech, Andreas; Leithe, Edward

    2016-01-01

    ABSTRACT In order to achieve accurate chromosome segregation, eukaryotic cells undergo a dramatic change in morphology to obtain a spherical shape during mitosis. Interphase cells communicate directly with each other by exchanging ions and small molecules via gap junctions, which have important roles in controlling cell growth and differentiation. As cells round up during mitosis, the gap junctional communication between mitotic cells and adjacent interphase cells ceases. Whether mitotic cells use alternative mechanisms for mediating direct cell-cell communication during rounding is currently unknown. Here, we have studied the mechanisms involved in the remodeling of gap junctions during mitosis. We further demonstrate that mitotic cells are able to form actin-based plasma membrane bridges with adjacent cells during rounding. These structures, termed “mitotic nanotubes,” were found to be involved in mediating the transport of cytoplasm, including Rab11-positive vesicles, between mitotic cells and adjacent cells. Moreover, a subpool of the gap-junction channel protein connexin43 localized in these intercellular bridges during mitosis. Collectively, the data provide new insights into the mechanisms involved in the remodeling of gap junctions during mitosis and identify actin-based plasma membrane bridges as a novel means of communication between mitotic cells and adjacent cells during rounding. PMID:27625181

  6. 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 ...

  7. Structural and functional analysis of critical amino acids in TMVI of the NHE1 isoform of the Na+/H+ exchanger.

    PubMed

    Tzeng, Jennifer; Lee, Brian L; Sykes, Brian D; Fliegel, Larry

    2011-09-01

    The mammalian Na(+)/H(+) exchanger isoform 1 (NHE1) resides on the plasma membrane and exchanges one intracellular H(+) for one extracellular Na(+). It maintains intracellular pH and regulates cell volume, and cell functions including growth and cell differentiation. Previous structural and functional studies on TMVI revealed several amino acids that are potentially pore lining. We examined these and other critical residues by site-directed mutagenesis substituting Asn227→Ala, Asp, Arg; Ile233→Ala; Leu243→Ala; Glu247→Asp, Gln; Glu248→Asp, Gln. Mutant NHE1 proteins were characterized in AP-1 cells, which do not express endogenous NHE1. All the TMVI critical amino acids were highly sensitive to substitution and changes often lead to a dysfunctional protein. Mutations of Asn227→Ala, Asp, Arg; Ile233→Ala; Leu243→Ala; Glu247→Asp; Glu248→Gln yielded significant reduction in NHE1 activity. Mutants of Asn227 demonstrated defects in protein expression, targeting and activity. Substituting Asn227→Arg and Ile233→Ala decreased the surface localization and expression of NHE1 respectively. The pore lining amino acids Ile233 and Leu243 were both essential for activity. Glu247 was not essential, but the size of the residue at this location was important while the charge on residue Glu248 was more critical to NHE1 function. Limited trypsin digestion on Leu243→Ala and Glu248→Gln revealed that they had increased susceptibility to proteolytic attack, indicating an alteration in protein conformation. Modeling of TMVI with TMXI suggests that these TM segments form part of the critical fold of NHE1 with Ile233 and Leu465 of TMXI forming a critical part of the extracellular facing ion conductance pathway.

  8. A critical size for emergence of nonbulk electronic and geometric structures in dodecanethiolate-protected Au clusters.

    PubMed

    Negishi, Yuichi; Nakazaki, Tafu; Malola, Sami; Takano, Shinjiro; Niihori, Yoshiki; Kurashige, Wataru; Yamazoe, Seiji; Tsukuda, Tatsuya; Häkkinen, Hannu

    2015-01-28

    We report on how the transition from the bulk structure to the cluster-specific structure occurs in n-dodecanethiolate-protected gold clusters, Au(n)(SC12)m. To elucidate this transition, we isolated a series of Au(n)(SC12)m in the n range from 38 to ∼520, containing five newly identified or newly isolated clusters, Au104(SC12)45, Au(∼226)(SC12)(∼76), Au(∼253)(SC12)(∼90), Au(∼356)(SC12)(∼112), and Au(∼520)(SC12)(∼130), using reverse-phase high-performance liquid chromatography. Low-temperature optical absorption spectroscopy, powder X-ray diffractometry, and density functional theory (DFT) calculations revealed that the Au cores of Au144(SC12)60 and smaller clusters have molecular-like electronic structures and non-fcc geometric structures, whereas the structures of the Au cores of larger clusters resemble those of the bulk gold. A new structure model is proposed for Au104(SC12)45 based on combined approach between experiments and DFT calculations.

  9. Archetypal Criticism.

    ERIC Educational Resources Information Center

    Chesebro, James W.; And Others

    1990-01-01

    Argues that archetypal criticism is a useful way of examining universal, historical, and cross-cultural symbols in classrooms. Identifies essential features of an archetype; outlines operational and critical procedures; illustrates archetypal criticism as applied to the cross as a symbol; and provides a synoptic placement for archetypal criticism…

  10. Long-Term Retention of an Intraorbital Metallic Foreign Body Adjacent to the Optic Nerve

    PubMed Central

    Siedlecki, Andrew N.; Deng, Jie; Miller, Donald M.

    2016-01-01

    We report the case of an asymptomatic 47 year-old male patient who suffered a penetrating wound from a metallic foreign body that became embedded adjacent to the optic nerve for over thirty years, as well as the associated examination, imaging, and fundus photography. Intraorbital metallic foreign bodies can be well tolerated and may not require surgical intervention despite proximity to important structures. PMID:27818817

  11. 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.

  12. Correlation of local structure peculiarities and critical current density of 2G MOCVD YBCO tapes with BaZrO3 nanoinclusions

    NASA Astrophysics Data System (ADS)

    Menushenkov, A. P.; Ivanov, V. G.; Chepikov, V. N.; Nygaard, R. R.; Soldatenko, A. V.; Rudnev, I. A.; Osipov, M. A.; Mineev, N. A.; Kaul, A. R.; Mathon, O.; Monteseguro, V.

    2017-04-01

    We have studied the influence of BaZrO3 nanoinclusions on the local structure and critical current density of second-generation high temperature superconducting tapes based on YBa2Cu3O7‑δ (YBCO) films. The films were made by metal–organic chemical vapor deposition (MOCVD). The crystal and local structure of the materials under study were analysed by x-ray diffraction and x-ray absorption spectroscopy (EXAFS + XANES). We have found that, being added at MOCVD process, Zr forms BaZrO3 nanoinclusions in YBCO matrix. The distance between Zr and the neighboring atoms is shorter than that one in a bulk crystalline BaZrO3, so we conclude that the nanoinclusions are in compressed state. The incorporation of 5 mol% BaZrO3 minimizes the static disorder of Cu–O bonds and maximizes their stiffness in YBCO. We show that the local structure peculiarities correlate well with the observed critical current behavior and consider this to be additional evidence in favor of small amounts of BaZrO3 nanoinclusions as efficient pinning centers.

  13. Critical behavior of the ferromagnetic q -state Potts model in fractal dimensions: Monte Carlo simulations on Sierpinski and Menger fractal structures

    NASA Astrophysics Data System (ADS)

    Monceau, Pascal

    2006-09-01

    The extension of the phase diagram of the q -state Potts model to noninteger dimension is investigated by means of Monte Carlo simulations on Sierpinski and Menger fractal structures. Both multicanonical and canonical simulations have been carried out with the help of the Wang-Landau and the Wolff cluster algorithms. Lower bounds are provided for the critical values qc of q where a first-order transition is expected in the cases of two structures whose fractal dimension is smaller than 2: The transitions associated with the seven-state and ten-state Potts models on Sierpinski carpets with fractal dimensions df≃1.8928 and df≃1.7925 , respectively, are shown to be second-order ones, the renormalization eigenvalue exponents yh are calculated, and bounds are provided for the renormalization eigenvalue exponents yt and the critical temperatures. Moreover, the results suggest that second-order transitions are expected to occur for very large values of q when the fractal dimension is lowered below 2—that is, in the case of hierarchically weakly connected systems with an infinite ramification order. At last, the transition associated with the four-state Potts model on a fractal structure with a dimension df≃2.631 is shown to be a weakly first-order one.

  14. Role of biomarkers in cardiac structure phenotyping in heart failure with preserved ejection fraction: critical appraisal and practical use.

    PubMed

    D'Elia, Emilia; Vaduganathan, Muthiah; Gori, Mauro; Gavazzi, Antonello; Butler, Javed; Senni, Michele

    2015-12-01

    Heart failure (HF) with preserved ejection fraction (HFpEF) is a heterogeneous clinical syndrome characterized by cardiovascular, metabolic, and pro-inflammatory diseases associated with advanced age and extracardiac comorbidities. All of these conditions finally lead to impairment of myocardial structure and function. The large phenotypic heterogeneity of HFpEF from pathophysiological underpinnings presents a major hurdle to HFpEF therapy. The new therapeutic approach in HFpEF should be targeted to each HF phenotype, instead of the 'one-size-fits-all' approach, which has not been successful in clinical trials. Unless the structural and biological determinants of the failing heart are deeply understood, it will be impossible to appropriately differentiate HFpEF patients, identify subtle myocardial abnormalities, and finally reverse abnormal cardiac function. Based on evidence from endomyocardial biopsies, some of the specific cardiac structural phenotypes to be targeted in HFpEF may be represented by myocyte hypertrophy, interstitial fibrosis, myocardial inflammation associated with oxidative stress, and coronary disease. Once the diagnosis of HFpEF has been established, a potential approach could be to use a panel of biomarkers to identify the main cardiac structural HFpEF phenotypes, guiding towards more appropriate therapeutic strategies. Accordingly, the purpose of this review is to investigate the potential role of biomarkers in identifying different cardiac structural HFpEF phenotypes and to discuss the merits of a biomarker-guided strategy in HFpEF.

  15. 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.

  16. 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.

  17. Self-organized criticality

    NASA Astrophysics Data System (ADS)

    Turcotte, Donald L.

    1999-10-01

    The concept of self-organized criticality was introduced to explain the behaviour of the sandpile model. In this model, particles are randomly dropped onto a square grid of boxes. When a box accumulates four particles they are redistributed to the four adjacent boxes or lost off the edge of the grid. Redistributions can lead to further instabilities with the possibility of more particles being lost from the grid, contributing to the size of each avalanche. These model 'avalanches' satisfied a power-law frequency-area distribution with a slope near unity. Other cellular-automata models, including the slider-block and forest-fire models, are also said to exhibit self-organized critical behaviour. It has been argued that earthquakes, landslides, forest fires, and species extinctions are examples of self-organized criticality in nature. In addition, wars and stock market crashes have been associated with this behaviour. The forest-fire model is particularly interesting in terms of its relation to the critical-point behaviour of the site-percolation model. In the basic forest-fire model, trees are randomly planted on a grid of points. Periodically in time, sparks are randomly dropped on the grid. If a spark drops on a tree, that tree and adjacent trees burn in a model fire. The fires are the `avalanches' and they are found to satisfy power-law frequency-area distributions with slopes near unity. This forest-fire model is closely related to the site-percolation model, that exhibits critical behaviour. In the forest-fire model there is an inverse cascade of trees from small clusters to large clusters, trees are lost primarily from model fires that destroy the largest clusters. This quasi steady-state cascade gives a power-law frequency-area distribution for both clusters of trees and smaller fires. The site-percolation model is equivalent to the forest-fire model without fires. In this case there is a transient cascade of trees from small to large clusters and a power

  18. Biomechanical effects of pedicle screw fixation on adjacent segments.

    PubMed

    Kyaw, Thein Aung; Wang, Zhuo; Sakakibara, Toshihiko; Yoshikawa, Takamasa; Inaba, Tadashi; Kasai, Yuichi

    2014-07-01

    Various biomechanical investigations have attempted to clarify the aetiology of adjacent segment disease (ASD). However, no biomechanical study has examined in detail the deformation behaviour of the adjacent segments when both pure torque and an angular displacement load are applied to the vertebrae along multiple segments. The purpose of this study is to investigate the biomechanical effects of pedicle screw fixation on adjacent segments. Ten cadaveric lumbar spines (L2-L5) of boars were used. Control and fusion models were prepared by disc damage and pedicle screw fixation of each specimen, and then, bending and rotation tests were performed using a six-axis material tester. In the biomechanical tests regulated by an angular displacement load, the range of motion (ROM) of the cranial and caudal adjacent segments in antero-posterior flexion and lateral bending was increased by about 20 % (p < 0.05), and the maximal torque in the fusion model was about threefold (p < 0.05) that in the control model. And in axial rotation, the ROM of cranial and caudal adjacent segments was increased by about 100 % (p < 0.001), and the maximal torque was about sixfold (p < 0.01) that in the control model. The ROM of adjacent segments was significantly increased after pedicle screw fixation as assessed by biomechanical tests regulated by an angular displacement load, but not in those regulated by torque. We present the results of biomechanical tests regulated by torque and angular displacement and show that the maximum torque of the fusion model was larger than that of the control model in the biomechanical test regulated by an angular displacement load, suggesting that mechanical stress on the segments adjacent to the fused segment is large. We think that ASD arises after spinal fusion surgery as a mechanism to compensate for the ROM lost due to excessive fusion by pedicle screw fixation, so that a large torque may be applied to adjacent segments within a physiologically

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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

  4. Structural Insight into the Critical Role of the N-Terminal Region in the Catalytic Activity of Dual-Specificity Phosphatase 26

    PubMed Central

    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

  5. A comparison of populations of island and adjacent mainland species of Caribbean Selenops (Araneae: Selenopidae) spiders.

    PubMed

    Crews, Sarah C; Puente-Rolón, Alberto R; Rutstein, Elliot; Gillespie, Rosemary G

    2010-03-01

    The role of the landscape in structuring populations has been the focus of numerous studies, in particular, the extent to which islands provide opportunities for isolation, and the consistency of such an effect across lineages. The current study examines this phenomenon using a series of relatively widespread taxa, all within a single genus of spiders, Selenops. We focus on the Caribbean Islands and adjacent Mesoamerican mainland to examine how the islands per se dictate structure across lineages. We use molecular genetic data from mitochondrial and nuclear genes to examine the population structure of seven species of Selenops. Comparisons are made between species found in the Greater Antilles, Lesser Antilles, and adjacent mainland. Results indicate that geography has little effect on the population structure of mainland species. In contrast, population structure appears to be partitioned by island in the insular Caribbean. Within islands, the amount of population structure for each species is variable and may be dictated more by ecological or demographic parameters, rather than geographic location. The overall conclusion is that the extent to which a given lineage is structured is highly variable across species, with this variability overwhelming any general signal of geographical isolation.

  6. Topology prediction of Brucella abortus Omp2b and Omp2a porins after critical assessment of transmembrane beta strands prediction by several secondary structure prediction methods.

    PubMed

    Paquet, J Y; Vinals, C; Wouters, J; Letesson, J J; Depiereux, E

    2000-02-01

    In order to propose a reliable model for Brucella porin topology, several structure prediction methods were evaluated in their ability to predict porin topology. Four porins of known structure were selected as test-cases and their secondary structure delineated. The specificity and sensitivity of 11 methods were separately evaluated. Our critical assessment shows that some secondary structure prediction methods (PHD, Dsc, Sopma) originally designed to predict globular protein structure are useful on porin topology prediction. The overall best prediction is obtained by combining these three "generalist" methods with a transmembrane beta strand prediction technique. This "consensus" method was applied to Brucella porins Omp2b and Omp2a, sharing no sequence homology with any other porin. The predicted topology is a 16-stranded antiparallel beta barrel with Omp2a showing a higher number of negatively charged residue in the exposed loops than Omp2b. Experiments are in progress to validate the proposed topology and the functional hypotheses. The ability of the proposed consensus method to predict topology of complex outer membrane protein is briefly discussed.

  7. Laplacian versus adjacency matrix in quantum walk search

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    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.

  8. Acetonitrile-induced unfolding of porcine pepsin A: A proposal for a critical role of hydration structures in conformational stability.

    PubMed

    Cardoso, T; Oliveira, C; Sarmento, A C; Pereira, A; Nutley, M A; Jess, T; Kelly, S M; Cooper, A; Price, N C; Pires, E; Barros, M

    2009-10-01

    In order to increase understanding of the basis of the stability of the native conformational state of porcine pepsin A, a strategy based on induction and monitoring of protein denaturation was developed. Structural perturbation was achieved by adding acetonitrile (MeCN) to the protein-solvent system. MeCN was found to induce non-coincident disruption of the secondary and tertiary structural features of pepsin A. It is proposed that gross unfolding is prompted by disruption of the protein hydration pattern induced by the organic co-solvent. It should be noted that the functional properties and thermal stability of the protein were already impaired before the onset of global unfolding. Low and intermediate contents of MeCN in the protein-solvent system affected the sharpness of the thermal transition and the degree of residual structure of the heat-denatured state. The importance of hydration to the conformational stability of pepsin A in its biologically active state is discussed.

  9. Crystal structures of ryanodine receptor SPRY1 and tandem-repeat domains reveal a critical FKBP12 binding determinant

    PubMed Central

    Yuchi, Zhiguang; Yuen, Siobhan M. Wong King; 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 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. PMID:26245150

  10. Critical incident reporting systems.

    PubMed

    Ahluwalia, Jag; Marriott, Lin

    2005-02-01

    Approximately 10% of all hospital admissions are complicated by critical incidents in which harm is caused to the patient - this amounts to more than 850,000 incidents annually. Critical incident reporting (CIR) systems refer to the structured reporting, collation and analysis of such incidents. This article describes the attributes required for an effective CIR system. Example neonatal trigger events and a management pathway for handling a critical incident report are described. The benefits and limitations of CIR systems, reactive and prospective approaches to the analysis of actual or potential critical incidents and the assessment of risk are also reviewed. Individual human error is but one contributor in the majority of critical incidents. Recognition of this and the fostering of an organisational culture that views critical incident reports as an opportunity to learn and to improve future patient care is vital if CIR systems are to be effective.

  11. 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.

  12. 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)-

  13. 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

  14. Modeling fires in adjacent ship compartments with computational fluid dynamics

    SciTech Connect

    Wix, S.D.; Cole, J.K.; Koski, J.A.

    1998-05-10

    This paper presents an analysis of the thermal effects on radioactive (RAM) transportation packages with a fire in an adjacent compartment. An assumption for this analysis is that the adjacent hold fire is some sort of engine room fire. Computational fluid dynamics (CFD) analysis tools were used to perform the analysis in order to include convective heat transfer effects. The analysis results were compared to experimental data gathered in a series of tests on tile US Coast Guard ship Mayo Lykes located at Mobile, Alabama.

  15. Management of adjacent segment disease after cervical spinal fusion.

    PubMed

    Kepler, Christopher K; Hilibrand, Alan S

    2012-01-01

    Adjacent segment disease (ASD) was described after long-term follow-up of patients treated with cervical fusion. The term describes new-onset radiculopathy or myelopathy referable to a motion segment adjacent to previous arthrodesis and often attributed to alterations in the biomechanical environment after fusion. Evidence suggests that ASD affects between 2% and 3% of patients per year. Although prevention of ASD was one major impetus behind the development of motion-sparing surgery, the literature does not yet clearly distinguish a difference in the rate of ASD between fusion and disk replacement. Surgical techniques during index surgery may reduce the rate of ASD.

  16. 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

  17. Critical rearing parameters of Tetrastichus planipennisi (Hymenoptera: Eulophidae) as affected by host plant substrate and host-parasitoid group structure.

    PubMed

    Duan, Jian J; Oppel, Craig

    2012-06-01

    In laboratory assays, we evaluated the potential impact of host plant substrate types, host-parasitoid group sizes (densities), and parasitoid-to-host ratios on select fitness parameters of the larval endoparasitoid Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae), newly introduced for biological control of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in the United States. Results from our study showed that offspring production and critical fitness parameters (body size and sex ratio) of T. planipennisi from parasitized emerald ash borer larvae are significantly influenced by host plant substrate type, host-parasitoid group size, parasitoid-to-host ratio, or a combination in the primary exposure assay. The number of both female and male T. planipennisi progeny was significantly greater when emerald ash borer larvae were inserted into tropical ash [Fraxinus uhdei (Wenz.) Lingelsh.] logs rather than green ash (Fraxinus pensylvanica Marshall). When maintained at a constant 1:1 parasitoid-to-host ratio, assays with larger host-parasitoid group sizes (3:3-12:12) produced significantly greater numbers of both male and female offspring per parental wasp compared with those with the single host-parasitoid (1:1) group treatment. As the parasitoid-to-host ratio increased from 1:1 to 8:1 in the assay, the average brood size (number of offspring per parasitized emerald ash borer larva) increased significantly, whereas the average brood sex ratio (female to male) changed from being female-biased (6:1) to male-biased (1:2); body size of female offspring as measured by the length of ovipositor and left hind tibia also was reduced significantly. Based on these findings, we suggest that the current method of rearing T. planipennisi with artificially infested-emerald ash borer larvae use the tropical ash logs for emerald ash borer insertion, a larger (> or = 3:3) host-parasitoid group size and 1:1 parasitoid-to-host ratio in the primary

  18. The ways of reliability enhancement of welded metal structures for critical applications in the conditions of low climatic temperatures

    NASA Astrophysics Data System (ADS)

    Saraev, Yu. N.; Bezborodov, V. P.; Gladkovsky, S. V.; Golikov, N. I.

    2016-11-01

    The paper studies how the energy parameters of an effective welding technology based on adaptive pulse-arc welding method influence the microstructure, mechanical characteristics and fatigue strength of low carbon steel 09G2S welded joint. It is established that the application of the adaptive pulse-arc welding method with modulated current (CMW) as compared to the welding method with direct current (DCW) allows one to obtain a welded joint of this steel with high reserve impact strength, dynamic fracture toughness and fatigue strength of metallic structures at operation temperatures up to -60°C.

  19. A programmable DNA origami nanospring that reveals force-induced adjacent binding of myosin VI heads.

    PubMed

    Iwaki, M; Wickham, S F; Ikezaki, K; Yanagida, T; Shih, W M

    2016-12-12

    Mechanosensitive biological nanomachines such as motor proteins and ion channels regulate diverse cellular behaviour. Combined optical trapping with single-molecule fluorescence imaging provides a powerful methodology to clearly characterize the mechanoresponse, structural dynamics and stability of such nanomachines. However, this system requires complicated experimental geometry, preparation and optics, and is limited by low data-acquisition efficiency. Here we develop a programmable DNA origami nanospring that overcomes these issues. We apply our nanospring to human myosin VI, a mechanosensory motor protein, and demonstrate nanometre-precision single-molecule fluorescence imaging of the individual motor domains (heads) under force. We observe force-induced transitions of myosin VI heads from non-adjacent to adjacent binding, which correspond to adapted roles for low-load and high-load transport, respectively. Our technique extends single-molecule studies under force and clarifies the effect of force on biological processes.

  20. 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.

  1. A programmable DNA origami nanospring that reveals force-induced adjacent binding of myosin VI heads

    PubMed Central

    Iwaki, M.; Wickham, S. F.; Ikezaki, K.; Yanagida, T.; Shih, W. M.

    2016-01-01

    Mechanosensitive biological nanomachines such as motor proteins and ion channels regulate diverse cellular behaviour. Combined optical trapping with single-molecule fluorescence imaging provides a powerful methodology to clearly characterize the mechanoresponse, structural dynamics and stability of such nanomachines. However, this system requires complicated experimental geometry, preparation and optics, and is limited by low data-acquisition efficiency. Here we develop a programmable DNA origami nanospring that overcomes these issues. We apply our nanospring to human myosin VI, a mechanosensory motor protein, and demonstrate nanometre-precision single-molecule fluorescence imaging of the individual motor domains (heads) under force. We observe force-induced transitions of myosin VI heads from non-adjacent to adjacent binding, which correspond to adapted roles for low-load and high-load transport, respectively. Our technique extends single-molecule studies under force and clarifies the effect of force on biological processes. PMID:27941751

  2. 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

  3. 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.

  4. Technical decision making with higher order structure data: utilization of differential scanning calorimetry to elucidate critical protein structural changes resulting from oxidation.

    PubMed

    Arthur, Kelly K; Dinh, Nikita; Gabrielson, John P

    2015-04-01

    Differential scanning calorimetry (DSC) is a useful tool for monitoring thermal stability of the molecular conformation of proteins. Here, we present an example of the sensitivity of DSC to changes in stability arising from a common chemical degradation pathway, oxidation. This Note is part of a series of industry case studies demonstrating the application of higher order structure data for technical decision making. For this study, six protein products from three structural classes were evaluated at multiple levels of oxidation. For each protein, the melting temperature (Tm ) decreased linearly as a function of oxidation; however, differences in the rate of change in Tm , as well as differences in domain Tm stability were observed across and within structural classes. For one protein, analysis of the impact of oxidation on protein function was also performed. For this protein, DSC was shown to be a leading indicator of decreased antigen binding suggesting a subtle conformation change may be underway that can be detected using DSC prior to any observable impact on product potency. Detectable changes in oxidized methionine by mass spectrometry (MS) occurred at oxidation levels below those with a detectable conformational or functional impact. Therefore, by using MS, DSC, and relative potency methods in concert, the intricate relationship between a primary structural modification, changes in conformational stability, and functional impact can be elucidated.

  5. Critical thinking.

    PubMed

    Price, A; Price, B

    1996-05-01

    Critical thinking is a process applied to midwifery theory, research and experience. It is a positive activity, responsive to context, drawing on negative and positive triggers and emotions to suggest ways of acting in future. Practice-based and reflective midwifery assignments should reflect the midwifery goals of critical thinking. This may require adjustments in assessment criteria and a questioning of standard academic conventions.

  6. 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…

  7. 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

  8. 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...

  9. 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

  10. Measurement Methods to Determine Air Leakage Between Adjacent Zones

    SciTech Connect

    Hult, Erin L.; Dickerhoff, Darryl J.; Price, Phillip N.

    2012-09-01

    Air leakage between adjacent zones of a building can lead to indoor air quality and energy efficiency concerns, however there is no existing standard for measuring inter-zonal leakage. In this study, synthesized data and field measurements are analyzed in order to explore the uncertainty associated with different methods for collecting and analyzing fan pressurization measurements to calculate interzone leakage.

  11. 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

  12. 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

  13. 11. View north from the adjacent B & O railroad ...

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

    11. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site, including Pier No. 4. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  14. 12. View north from the adjacent B & O railroad ...

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

    12. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site, including Pier No. 4. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  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. 47 CFR 73.810 - Third adjacent channel interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.810 Third adjacent channel... power FM, FM translator or FM booster station to such affected station and to the Commission. (ii) A full power FM, FM translator or FM booster station shall review all complaints it receives,...

  17. 47 CFR 73.810 - Third adjacent channel interference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.810 Third adjacent channel... power FM, FM translator or FM booster station to such affected station and to the Commission. (ii) A full power FM, FM translator or FM booster station shall review all complaints it receives,...

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

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

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

    3. View of side of house facing north from adjacent property. Original wood siding and trim is visible. Note: later addition to rear of house is shown in right side of photograph. - 322 South Fifteenth Street (House), Louisville, Jefferson County, KY

  4. 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

  5. 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.

  6. MTR COOLING TOWER. BASIN IS ADJACENT TO PUMP HOUSE. CAMERA ...

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

    MTR COOLING TOWER. BASIN IS ADJACENT TO PUMP HOUSE. CAMERA FACES SOUTHEAST TOWARD NORTH SIDE OF PUMP HOUSE. INL NEGATIVE NO. 2690. Unknown Photographer, 6/1951. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  7. 1. VIEW FROM SOUTHWEST SHOWING SOUTH (FRONT) ELEVATION, ADJACENT LOUGHRAN ...

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

    1. VIEW FROM SOUTHWEST SHOWING SOUTH (FRONT) ELEVATION, ADJACENT LOUGHRAN BUILDING (BASSIN'S RESTAURANT) (HABS No. DC-357), 501-511 14TH STREET (THE LOCKER ROOM) HABS No. DC-356) ON CORNER, AND MUNSEY BUILDING (HABS No. DC-358) - William J. Stone Building, 1345 E Street Northwest, Washington, District of Columbia, DC

  8. 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

  9. 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

  10. 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

  11. Structure-Function Analysis of VapB4 Antitoxin Identifies Critical Features of a Minimal VapC4 Toxin-Binding Module

    PubMed Central

    Jin, Guangze; Pavelka, Martin S.

    2015-01-01

    ABSTRACT Bacterial toxin-antitoxin systems play a critical role in the regulation of gene expression, leading to developmental changes, reversible dormancy, and cell death. Type II toxin-antitoxin pairs, composed of protein toxins and antitoxins, exist in nearly all bacteria and are classified into six groups on the basis of the structure of the toxins. The VapBC group comprises the most common type II system and, like other toxin-antitoxin systems, functions to elicit dormancy by inhibiting protein synthesis. Activation of toxin function requires protease degradation of the VapB antitoxin, which frees the VapC toxin from the VapBC complex, allowing it to hydrolyze the RNAs required for translation. Generally, type II antitoxins bind with high specificity to their cognate toxins via a toxin-binding domain and endow the complex with DNA-binding specificity via a DNA-binding domain. Despite the ubiquity of VapBC systems and their critical role in the regulation of gene expression, few functional studies have addressed the details of VapB-VapC interactions. Here we report on the results of experiments designed to identify molecular determinants of the specificity of the Mycobacterium tuberculosis VapB4 antitoxin for its cognate VapC4 toxin. The results identify the minimal domain of VapB4 required for this interaction as well as the amino acid side chains required for binding to VapC4. These findings have important implications for the evolution of VapBC toxin-antitoxin systems and their potential as targets of small-molecule protein-protein interaction inhibitors. IMPORTANCE VapBC toxin-antitoxin pairs are the most widespread type II toxin-antitoxin systems in bacteria, where they are thought to play key roles in stress-induced dormancy and the formation of persisters. The VapB antitoxins are critical to these processes because they inhibit the activity of the toxins and provide the DNA-binding specificity that controls the synthesis of both proteins. Despite the

  12. Critical role of CD4 T cells in maintaining lymphoid tissue structure for immune cell homeostasis and reconstitution.

    PubMed

    Zeng, Ming; Paiardini, Mirko; Engram, Jessica C; Beilman, Greg J; Chipman, Jeffrey G; Schacker, Timothy W; Silvestri, Guido; Haase, Ashley T

    2012-08-30

    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.

  13. Reduced graphene oxide composites with water soluble copolymers having tailored lower critical solution temperatures and unique tube-like structure

    PubMed Central

    Namvari, Mina; Biswas, Chandra S.; Galluzzi, Massimiliano; Wang, Qiao; Du, Bing; Stadler, Florian J.

    2017-01-01

    Nanohybrids of graphene with water soluble polymer were synthesized using ‘grafting from’ method. GO, prepared by modified Hummers’ method, was first reacted with sodium azide. Alkyne-terminated RAFT-CTA was synthesized by reaction of propargyl alcohol and S-1-dodecyl-S’-(α,α‘-dimethyl-α”-acetic acid) trithiocarbonate. RAFT-CTA was grafted onto the GO sheets by facile click-reaction and subsequently, N-isopropylacrylamide (NIPAM) and N-ethyleacrylamide (NEAM) were polymerized on graphene sheets via RAFT polymerization method. The respective copolymers with different ratios were also prepared. The nanohybrids were characterized by FTIR, XRD, TGA, Raman, SEM, and AFM. Both SEM and AFM clearly showed rod-like structures for rGO-PNEAM. XRD showed a small peak at 2θ = 19.21°, corresponding to d-spacing ≈ 4.6 Å. In addition, the nanohybrids showed a very broad temperature range for the LCST in water between ca. 30 and 70 °C. PMID:28291225

  14. Reduced graphene oxide composites with water soluble copolymers having tailored lower critical solution temperatures and unique tube-like structure

    NASA Astrophysics Data System (ADS)

    Namvari, Mina; Biswas, Chandra S.; Galluzzi, Massimiliano; Wang, Qiao; Du, Bing; Stadler, Florian J.

    2017-03-01

    Nanohybrids of graphene with water soluble polymer were synthesized using ‘grafting from’ method. GO, prepared by modified Hummers’ method, was first reacted with sodium azide. Alkyne-terminated RAFT-CTA was synthesized by reaction of propargyl alcohol and S-1-dodecyl-S’-(α,α‘-dimethyl-α”-acetic acid) trithiocarbonate. RAFT-CTA was grafted onto the GO sheets by facile click-reaction and subsequently, N-isopropylacrylamide (NIPAM) and N-ethyleacrylamide (NEAM) were polymerized on graphene sheets via RAFT polymerization method. The respective copolymers with different ratios were also prepared. The nanohybrids were characterized by FTIR, XRD, TGA, Raman, SEM, and AFM. Both SEM and AFM clearly showed rod-like structures for rGO-PNEAM. XRD showed a small peak at 2θ = 19.21°, corresponding to d-spacing ≈ 4.6 Å. In addition, the nanohybrids showed a very broad temperature range for the LCST in water between ca. 30 and 70 °C.

  15. Critical role of γ-phosphate in structural transition of Na,K-ATPase upon ATP binding

    NASA Astrophysics Data System (ADS)

    Petrushanko, Irina Yu.; Mitkevich, Vladimir A.; Anashkina, Anastasia A.; Klimanova, Elizaveta A.; Dergousova, Elena A.; Lopina, Olga D.; Makarov, Alexander A.

    2014-06-01

    Active transport of sodium and potassium ions by Na,K-ATPase is accompanied by the enzyme conformational transition between E1 and E2 states. ATP and ADP bind to Na,K-ATPase in the E1 conformation with similar affinity but the properties of enzyme in complexes with these nucleotides are different. We have studied thermodynamics of Na,K-ATPase binding with adenine nucleotides at different temperatures using isothermal titration calorimetry. Our data indicate that β-phosphate is involved in complex formation by increasing the affinity of adenine nucleotides to Na,K-ATPase by an order of magnitude, while γ-phosphate does not affect it. ATP binding to Na,K-ATPase in contrast to ADP binding generates a structural transition in the enzyme, which is consistent with the movement of a significant portion of the surface area to a solvent-protected state. We propose that ATP binding leads to convergence of the nucleotide-binding and phosphorylation domains transferring the enzyme from the ``E1-open'' to ``E1-closed'' conformation ready for phosphorylation.

  16. Reduced graphene oxide composites with water soluble copolymers having tailored lower critical solution temperatures and unique tube-like structure.

    PubMed

    Namvari, Mina; Biswas, Chandra S; Galluzzi, Massimiliano; Wang, Qiao; Du, Bing; Stadler, Florian J

    2017-03-14

    Nanohybrids of graphene with water soluble polymer were synthesized using 'grafting from' method. GO, prepared by modified Hummers' method, was first reacted with sodium azide. Alkyne-terminated RAFT-CTA was synthesized by reaction of propargyl alcohol and S-1-dodecyl-S'-(α,α'-dimethyl-α"-acetic acid) trithiocarbonate. RAFT-CTA was grafted onto the GO sheets by facile click-reaction and subsequently, N-isopropylacrylamide (NIPAM) and N-ethyleacrylamide (NEAM) were polymerized on graphene sheets via RAFT polymerization method. The respective copolymers with different ratios were also prepared. The nanohybrids were characterized by FTIR, XRD, TGA, Raman, SEM, and AFM. Both SEM and AFM clearly showed rod-like structures for rGO-PNEAM. XRD showed a small peak at 2θ = 19.21°, corresponding to d-spacing ≈ 4.6 Å. In addition, the nanohybrids showed a very broad temperature range for the LCST in water between ca. 30 and 70 °C.

  17. 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

  18. 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.

  19. Can electromagnetic fields influence the structure and enzymatic digest of proteins? A critical evaluation of microwave-assisted proteomics protocols.

    PubMed

    Damm, Markus; Nusshold, Christoph; Cantillo, David; Rechberger, Gerald N; Gruber, Karl; Sattler, Wolfgang; Kappe, C Oliver

    2012-10-22

    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.

  20. 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

  1. 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…

  2. 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.

  3. Use of human lung tissue for studies of structural changes associated with chronic ozone exposure: opportunities and critical issues.

    PubMed Central

    Lippmann, M

    1993-01-01

    Definitive information on the chronic effects of exposure to ozone (O3) 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 O3 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 O3. This paper discusses the advantages and limitations of further studies of structural changes in human lung tissue in relation to chronic O3 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. PMID:8206033

  4. On the critical evaluation of growth/no growth assessment of Zygosaccharomyces bailii with optical density measurements: liquid versus structured media.

    PubMed

    Mertens, L; Van Derlinden, E; Dang, T D T; Cappuyns, A M; Vermeulen, A; Debevere, J; Moldenaers, P; Devlieghere, F; Geeraerd, A H; Van Impe, J F

    2011-06-01

    Growth/no growth (G/NG) studies that include the effect of medium structure have typically been performed for (pathogenic) bacteria and on the basis of gelatin/agar as a gelling agent. In this study, the growth potential of the spoilage yeast Zygosaccharomyces bailii was investigated in two model systems that resemble the macroscopic physicochemical and rheological properties of acidic sauces. In a Carbopol model system, the effect of pH (3.5-4.5), glycerol concentration (17-32%), acetic acid concentration (1.5-2.0%) and medium structure (3 levels) was investigated. In xanthan gum, the behavior of the yeast was studied at different levels of pH (3.5-4.5), NaCl concentration (0.5-13.5%), acetic acid concentration (0-2.0%) and medium structure (2 levels). Rheologically, viscoelastic moduli failed to discriminate between different forms of microbial growth, whereas yield stress data appeared to provide a better indication. In general, G/NG results revealed an unexpected increase of growth probability as a function of medium structure, both at 22 and 30 °C. Whether this behavior is the result of an underlying growth-promoting mechanism could not be explained from a macroscopic point of view (e.g., macrorheology, a(w)), but may be more related to the local microscopic properties of the gels. In a second part of this study, the potential use and information content of optical density measurements for G/NG data collection in structured media were critically evaluated and confronted with their practical relevance to the food industry.

  5. Structure-function analysis of the human ferroportin iron exporter (SLC40A1): effect of hemochromatosis type 4 disease mutations and identification of critical residues.

    PubMed

    Le Gac, Gérald; Ka, Chandran; Joubrel, Rozenn; Gourlaouen, Isabelle; Lehn, Pierre; Mornon, Jean-Paul; Férec, Claude; Callebaut, Isabelle

    2013-10-01

    Ferroportin (SLC40A1) is the only known iron exporter in mammals and is considered a key coordinator of the iron balance between intracellular and systemic iron homeostasis. However, the structural organization of ferroportin in the lipid bilayer remains controversial and very little is known about the mechanism underlying iron egress. In the present study, we have developed an approach based on comparative modeling, which has led to the construction of a model of the three-dimensional (3D) structure of ferroportin by homology to the crystal structure of a Major Facilitator Superfamily member (EmrD). This model predicts atomic details for the organization of ferroportin transmembrane helices and is in agreement with our current understanding of the ferroportin function and its interaction with hepcidin. Using in vitro experiments, we demonstrate that this model can be used to identify novel critical amino acids. In particular, we show that the tryptophan residue 42 (p.Trp42), which is localized within the extracellular end of the ferroportin pore, is likely involved in both the iron export function and in the mechanism of inhibition by hepcidin. Thus, our 3D model provides a new perspective for understanding the molecular basis of ferroportin functions and dysfunctions.

  6. The Objective Structured Clinical Examination (OSCE) as a strategy for assessing clinical competence in midwifery education in Ireland: a critical review.

    PubMed

    Smith, Valerie; Muldoon, Kathryn; Biesty, Linda

    2012-09-01

    In Ireland, to register as a midwife, all student midwives must be deemed competent to practice with the assessment of competence an essential component of midwifery education. A variety of assessment strategies, including observed practice, clinical interviews, portfolios of reflection, the Objective Structured Clinical Examination (OSCE) and written examination papers, are utilised to assess midwifery students' clinical competence. In this paper, a critical review of the OSCE as a strategy for assessing clinical competence in one third level institution in Ireland is offered. Although utilised for assessing competence across a range of areas (e.g. obstetric emergencies and pharmacology/drug administration), the use of the OSCE for assessing midwifery students' competence in lactation and infant feeding practices, as an example for this paper, is described. The advantages, disadvantages, validity and reliability of the OSCE, as an assessment strategy, are critically explored. Recognising that no single assessment strategy can provide all the information required to assess something as complex as clinical performance, the OSCE, when viewed alongside other forms of assessment, and with relevance to the topic under examination, may be considered a valuable strategy for enhancing the assessment of students' clinical competence, and for embracing diversity within midwifery education and training.

  7. 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 ...

  8. Critical Careers.

    ERIC Educational Resources Information Center

    Bowles, Roger A.

    2001-01-01

    Reports the critical shortage of qualified equipment technicians, especially in biomedical equipment. Cites the importance of encouraging careers in this field and describes a source of occupational information. (SK)

  9. 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.

  10. 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

  11. 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

  12. 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

  13. Surgical treatment of complex axis fractures with adjacent segment instability.

    PubMed

    Wang, Lei; Xia, Tian; Dong, Shuanghai; Zhao, Qinghua; Tian, Jiwei

    2012-03-01

    This study investigates the clinical and radiographic characteristics of complex axis fractures with adjacent segment instability and describes the outcome of surgical treatment. Twenty-one patients (14 male, seven female; mean age=34 years) with complex axis fractures and adjacent segment instability who were treated between August 2003 and June 2009 were retrospectively reviewed. Treatment selection was based on fracture type and stability of the upper cervical segments. All patients were immobilized with a hard collar for three months after surgery. The mean follow-up period was 12 months (range=6-36 months). No intraoperative surgery-related complications were observed and fusion was achieved in all patients. The outcome was excellent for 17 patients, good for two patients, fair for one patient, and poor for one patient. The upper cervical segments that can become unstable due to complex axis fractures include the atlantoaxial and C2-3 joints. Recommended surgical treatments produce good results.

  14. On the Circulation Manifold for Two Adjacent Lifting Sections

    NASA Technical Reports Server (NTRS)

    Zannetti, Luca; Iollo, Angelo

    1998-01-01

    The circulation functional relative to two adjacent lifting sections is studied for two cases. In the first case we consider two adjacent circles. The circulation is computed as a function of the displacement of the secondary circle along the axis joining the two centers and of the angle of attack of the secondary circle, The gradient of such functional is computed by deriving a set of elliptic functions with respect both to their argument and to their Period. In the second case studied, we considered a wing-flap configuration. The circulation is computed by some implicit mappings, whose differentials with respect to the variation of the geometrical configuration in the physical space are found by divided differences. Configurations giving rise to local maxima and minima in the circulation manifold are presented.

  15. 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.

  16. Structure and stability of superconducting core of single-core MgB2/Cu,Nb tube composite with a high critical current

    NASA Astrophysics Data System (ADS)

    Krinitsina, T. P.; Kuznetsova, E. I.; Blinova, Yu. V.; Rakov, D. N.; Belotelova, Yu. N.; Sudareva, S. V.; Degtyarev, M. V.; Romanov, E. P.

    2014-06-01

    The core of a single-core MgB2/Cu,Nb composite, which has been prepared by the ex-situ technique and exhibits a high critical current equal to 427 A (at 0 T and 4.2 K, j c ≥ 105 A/cm2), has been studied using various structural methods. Two kinds of MgB2 crystals were observed; those of the first kind is large, highly dense crystals characterized by a low oxygen content (2-8 at %) and the others are fine, weakly coupled crystallites characterized by high oxygen content (4-21 at %). To perform a comparative analysis of the structures, we have also studied an MgB2 bulk sample synthesized at 1000°C. It was found that two phases with the same lattice are formed; they differ in the magnesium and boron contents (within the homogeneity range), impurity oxygen content and microstructure as well but differ slightly in the lattice parameters. The two-phase state of MgB2 bulk sample is due to the mechanism of its formation, which includes the melting of magnesium, the dissolution of solid boron in it, and the crystallization of MgB2 from the melt with the formation of dendrite-like structure characterized by corresponding redistribution of components and impurities. To a certain degree, the two-phase structure of MgB2 bulk sample is inherited by the MgB2/Cu,Nd composite prepared by ex-situ technique (annealing of composite at 700°C). It was shown that oxygen in the MgB2 compound is the destabilizing factor and leads to the transformation of the superconductor into MgO.

  17. Osmium complex binding to mismatched methylcytosine: effect of adjacent bases.

    PubMed

    Nomura, Akiko; Tainaka, Kazuki; Okamoto, Akimitsu

    2009-01-01

    We investigated the efficiency of osmium complex formation at 5-methylcytosine in mismatched DNA duplexes. Osmium complexation was not observed in fully matched duplexes, whereas the complexation site and efficiency in mismatched duplexes depended on the 5'-neighboring base of the 5-methylcytosine. In particular, when the base adjacent to the 5' side of the mismatched base pair was thymine, a unique side reaction was observed. However, the mismatched base pairs did not influence the selectivity of osmium complexation with methylated DNA.

  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. 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

  20. Four-body central configurations with adjacent equal masses

    NASA Astrophysics Data System (ADS)

    Deng, Yiyang; Li, Bingyu; Zhang, Shiqing

    2017-04-01

    For any convex non-collinear central configuration of the planar Newtonian 4-body problem with adjacent equal masses m1 =m2 ≠m3 =m4, with equal lengths for the two diagonals, we prove it must possess a symmetry and must be an isosceles trapezoid; furthermore, which is also an isosceles trapezoid when the length between m1 and m4 equals the length between m2 and m3.

  1. 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

  2. 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

  3. Predicting Agenesis of the Mandibular Second Premolar from Adjacent Teeth

    PubMed Central

    2015-01-01

    Early diagnosis of agenesis of the mandibular second premolar (P2) enhances management of the dental arch in the growing child. The aim of this study was to explore the relationship in the development of the mandibular first molar (M1) and first premolar (P1) at early stages of P2 (second premolar). Specifically, we ask if the likelihood of P2 agenesis can be predicted from adjacent developing teeth. We selected archived dental panoramic radiographs with P2 at crown formation stages (N = 212) and calculated the likelihood of P2 at initial mineralisation stage ‘Ci’ given the tooth stage of adjacent teeth. Our results show that the probability of observing mandibular P2 at initial mineralisation stage ‘Ci’ decreased as both the adjacent P1 and M1 matured. The modal stage at P2 ‘Ci’ was P1 ‘Coc’ (cusp outline complete) and M1 ‘Crc’ (crown complete). Initial mineralisation of P2 was observed up to P1 ‘Crc’ and M1 stage ‘R½’ (root half). The chance of observing P2 at least ‘Coc’ (coalescence of cusps) was considerably greater prior to these threshold stages compared to later stages of P1 and M1. These findings suggest that P2 is highly unlikely to develop if P1 is beyond ‘Crc’ and M1 is beyond ‘R½’. PMID:26673218

  4. Adjacent Segment Disease in the Cervical and Lumbar Spine.

    PubMed

    Tobert, Daniel G; Antoci, Valentin; Patel, Shaun P; Saadat, Ehsan; Bono, Christopher M

    2017-04-01

    Adjacent segment disease (ASD) is disappointing long-term outcome for both the patient and clinician. In contrast to adjacent segment degeneration, which is a common radiographic finding, ASD is less common. The incidence of ASD in both the cervical and lumbar spine is between 2% and 4% per year, and ASD is a significant contributor to reoperation rates after spinal arthrodesis. The etiology of ASD is multifactorial, stemming from existing spondylosis at adjacent levels, predisposed risk to degenerative changes, and altered biomechanical forces near a previous fusion site. Numerous studies have sought to identify both patient and surgical risk factors for ASD, but a consistent, sole predictor has yet to be found. Spinal arthroplasty techniques seek to preserve physiological biomechanics, thereby minimizing the risk of ASD, and long-term clinical outcome studies will help quantify its efficacy. Treatment strategies for ASD are initially nonoperative, provided a progressive neurological deficit is not present. The spine surgeon is afforded many surgical strategies once operative treatment is elected. The goal of this manuscript is to consider the etiologies of ASD, review its manifestations, and offer an approach to treatment.

  5. Perceptual processing of adjacent and nonadjacent tactile nontargets.

    PubMed

    Evans, P M; Craig, J C; Rinker, M A

    1992-11-01

    Previous research has shown that subjects appear unable to restrict processing to a single finger and ignore a stimulus presented to an adjacent finger. Furthermore, the evidence suggests that, at least for moving stimuli, an adjacent nontarget is fully processed to the level of incipient response activation. The present study replicated and expanded upon these original findings. The results of Experiment 1 showed that an equally large response-competition effect occurred when the nontarget was presented to adjacent and nonadjacent fingers (on the same hand). The results of Experiment 2 showed that the effects observed in Experiment 1 (and in previous studies) were also obtained with stationary stimuli. Although small, there was some indication in the results of Experiment 2 that interference may dissipate more rapidly with distance with stationary stimuli. An additional finding was that interference effects were observed in both experiments with temporal separations between the target and nontarget of up to 100 msec. In Experiment 3, target and nontarget stimuli were presented to opposite hands. Although reduced, interference was still evident with target and nontarget stimuli presented to opposite hands. Varying the physical distance between hands did not produce any change in the amount of interference. The results suggest that the focus of attention on the skin extends nearly undiminished across the fingers of one hand and is not dependent upon the physical distance between sites of stimulation.

  6. 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.

  7. 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.

  8. Historic surface faulting in continental United States and adjacent parts of Mexico

    USGS Publications Warehouse

    Bonilla, M.G.

    1967-01-01

    This report summarizes geometric aspects of approximately 35 instances of historic faulting of the ground surface in the continental United States and adjacent parts of Mexico. This information is of immediate importance in the selection and evaluation of sites for vital structures such as nuclear power plants. The data are presented in a table and graphs which show the quantitative relations between various aspects of the faulting. Certain items in the table that are uncertain, poorly known, or not in the published literature are briefly described in the text.

  9. 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

  10. 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

  11. Interleukin-10 Is Produced by a Specific Subset of Taste Receptor Cells and Critical for Maintaining Structural Integrity of Mouse Taste Buds

    PubMed Central

    Chai, Jinghua; Zhou, Minliang; Simon, Nirvine; Huang, Liquan

    2014-01-01

    Although inflammatory responses are a critical component in defense against pathogens, too much inflammation is harmful. Mechanisms have evolved to regulate inflammation, including modulation by the anti-inflammatory cytokine interleukin-10 (IL-10). Previously we have shown that taste buds express various molecules involved in innate immune responses, including the proinflammatory cytokine tumor necrosis factor (TNF). Here, using a reporter mouse strain, we show that taste cells also express the anti-inflammatory cytokine IL-10. Remarkably, IL-10 is produced by only a specific subset of taste cells, which are different from the TNF-producing cells in mouse circumvallate and foliate taste buds: IL-10 expression was found exclusively in the G-protein gustducin-expressing bitter receptor cells, while TNF was found in sweet and umami receptor cells as reported previously. In contrast, IL-10R1, the ligand-binding subunit of the IL-10 receptor, is predominantly expressed by TNF-producing cells, suggesting a novel cellular hierarchy for regulating TNF production and effects in taste buds. In response to inflammatory challenges, taste cells can increase IL-10 expression both in vivo and in vitro. These findings suggest that taste buds use separate populations of taste receptor cells that coincide with sweet/umami and bitter taste reception to modulate local inflammatory responses, a phenomenon that has not been previously reported. Furthermore, IL-10 deficiency in mice leads to significant reductions in the number and size of taste buds, as well as in the number of taste receptor cells per taste bud, suggesting that IL-10 plays critical roles in maintaining structural integrity of the peripheral gustatory system. PMID:24523558

  12. 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.; Jayko, Angela S.; Irwin, W.P.; Aalto, K.R.; Carver, G.A.; Clarke, S.H.; 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

  13. Digital depth horizon compilations of the Alaskan North Slope and adjacent Arctic regions

    USGS Publications Warehouse

    Saltus, Richard W.; Bird, Kenneth J.

    2003-01-01

    Data have been digitized and combined to create four detailed depth horizon grids spanning the Alaskan North Slope and adjacent offshore areas. These map horizon compilations were created to aid in petroleum system modeling and related studies. Topography/bathymetry is extracted from a recent Arctic compilation of global onshore DEM and satellite altimetry and ship soundings offshore. The Lower Cretaceous Unconformity (LCU), the top of the Triassic Shublik Formation, and the pre-Carboniferous acoustic basement horizon grids are created from numerous seismic studies, drill hole information, and interpolation. These horizons were selected because they mark critical times in the geologic evolution of the region as it relates to petroleum. The various horizons clearly show the major tectonic elements of this region including the Brooks Range, Colville Trough, Barrow Arch, Hanna Trough, Chukchi Platform, Nuwuk Basin, Kaktovik Basin, and Canada Basin. The gridded data are available in a variety of data formats for use in regional studies.

  14. 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.

  15. Soil chemistry adjacent to roads treated with dust control products at Squaw Creek National Wildlife Refuge

    USGS Publications Warehouse

    Kunz, Bethany K.

    2016-01-01

    The health of soils along roadways is critical for maximizing habitat quality and minimizing negative ecological effects of roads. Adjacent to unpaved roads, soil chemistry may be altered by the deposition of dust, as well as by road treatment with dust suppressants or soil stabilizer products. If present in roadside soils, these product residues may be available to plants, terrestrial invertebrates, or small mammals. Unfortunately, very few studies have attempted to track the transport of dust suppressants after application. As part of a larger ongoing study on the environmental effects of dust suppressant products on roadside plants and animals, we sampled roadside soils at Squaw Creek National Wildlife Refuge (NWR). Replicated road sections at Squaw Creek NWR had been previously treated with two road products—calcium chloride-based durablend-C™ and synthetic iso-alkane EnviroKleen®. In order to quantify the effect of dust suppressant treatment on roadside soils, we took replicated composite soil samples one year after treatment at 1m and 4m from the road’s edge, and analyzed samples for a suite of soil chemistry variables (pH, conductivity, NO3-N, P, K, Ca, Mg, Na and S). We also assessed dust suppressant product residues in the soil. For durablend-C™, we used soil conductivity as an indicator. For EnviroKleen®, we developed a method for extraction and isolation, followed by analysis with gas chromatography/mass spectrometry to look for a specific EnviroKleen® signature. Surprisingly, soil conductivity was not elevated adjacent to road sections treated with durablend-C™, relative to other sections. EnviroKleen® was detectable at both 1m and 4m from treated sections at concentrations from 1 to 1500 mg/kg, and was non-detectable in soils adjacent to the untreated section. The most notable characteristic of soils across all treated and untreated sections at 1m was elevated calcium (up to 30,000 mg/kg), likely as a result of dust deposition from the

  16. 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.

  17. 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

  18. Adjacent segment disease and C-ADR: promises fulfilled?

    PubMed Central

    Riew, K Daniel; Schenk-Kisser, Jeannette M.; Skelly, Andrea C.

    2012-01-01

    Study design: Systematic review. Clinical question: Do the rates and timing of adjacent segment disease (ASD) differ between cervical total disc arthroplasty (C-ADR) and anterior cervical discectomy and fusion (ACDF) in patients treated for cervical degenerative disc disease? Methods: A systematic search of MEDLINE/PubMed and bibliographies of key articles was done to identify studies with long-term follow-up for symptomatic and/or radiographic ASD comparing C-ADR with fusion for degenerative disc disease of the cervical spine. The focus was on studies with longer follow-up (48–60 months) of primary US Food and Drug Administration trials of Prestige ST, Prodisc-C, and Bryan devices as available. Trials of other discs with a minimum of 24 months follow-up were considered for inclusion. Studies evaluating lordosis/angle changes at adjacent segments and case series were excluded. Results: From 14 citations identified, four reports from three randomized controlled trials and four nonrandomized studies are summarized. Risk differences between C-ADR and ACF for symptomatic ASD were 1.5%–2.3% and were not significant across RCT reports. Time to development of ASD did not significantly differ between treatments. Rates of radiographic ASD were variable. No meaningful comparison of ASD rates based on disc design was possible. No statistical differences in adjacent segment range of motion were noted between treatment groups. Conclusion: Our analysis reveals that, to date, there is no evidence that arthroplasty decreases ASD compared with ACDF; the promise of arthroplasty decreasing ASD has not been fulfilled. PMID:23236312

  19. 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.

  20. Stereoselective Organocatalytic Synthesis of Oxindoles with Adjacent Tetrasubstituted Stereocenters.

    PubMed

    Engl, Oliver D; Fritz, Sven P; Wennemers, Helma

    2015-07-06

    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.

  1. 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.

  2. Astronaut Charles Duke stands at rock adjacent to 'House Rock'

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Astronaut Charles M. Duke Jr., Apollo 16 lunar module pilot, stands at a rock adjacent (south) to the huge 'House Rock' (barely out of view at right edge). Note shadow at extreme right center where the two moon-exploring crewmen of the mission sampled what they referred to as the 'eastwest split of House Rock' or the open space between this rock and 'House Rock'. Duke has a sample bag in his hand, and a lunar surface rake leans against the large boulder.

  3. Empires and percolation: stochastic merging of adjacent regions

    NASA Astrophysics Data System (ADS)

    Aldous, D. J.; Ong, J. R.; Zhou, W.

    2010-01-01

    We introduce a stochastic model in which adjacent planar regions A, B merge stochastically at some rate λ(A, B) and observe analogies with the well-studied topics of mean-field coagulation and of bond percolation. Do infinite regions appear in finite time? We give a simple condition on λ for this hegemony property to hold, and another simple condition for it to not hold, but there is a large gap between these conditions, which includes the case λ(A, B) ≡ 1. For this case, a non-rigorous analytic argument and simulations suggest hegemony.

  4. Critical Information at Critical Moments

    ERIC Educational Resources Information Center

    Fierman, Ben; Thrower, Raymond H., Jr.

    2011-01-01

    On a daily basis, administrators are reminded of the potential, perhaps the likelihood, of violence or natural crises on their campuses. Comprehensive studies have been conducted and point to recommendations and best practices for planning, preparing, responding to, and recovering from critical incidents. The International Association of Campus…

  5. Investigation on Reflection of Tectonic Pattern in ASG EUPOS Data in the Sudetes and Adjacent Areas

    NASA Astrophysics Data System (ADS)

    Szczerbowski, Zbigniew

    2016-12-01

    The GNSS data evaluated from on observation of ASG EUPOS stations in the Sudety Mts. and in adjacent areas is analyzed by the author in the scope of disturbances in daily solutions that can be induced by tectonics stress. The daily position changes derived from GNSS data demonstrate the long or short term trends, which are affected by offsets of different nature. Author presents an analysis based on frequency of parameter - displacement vector azimuth. The aim of the analysis is to show statistical significance of observed small values of temporal displacements, which values are not normally distributed. There are "outliers" of the normal distribution of displacement azimuths, which values show a certain reproducibility, which corresponds to orientations of tectonic lines. That suggests small, short time movements along boundaries of horsts and grabens - a crustal-extension structure of the area. However derived results (values of displacements) are less than a limitation error, temporal distributions of coordinates are not random as usually data errors. So in author's opinion the spatial-temporal evolution of horizontal displacements of ASG EUPOS stations in the Sudety Mts. and in adjacent areas are determined by expressions of underlying geological structures.

  6. 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.

  7. Structure of C-terminal Tandem BRCT Repeats of Rtt107 Protein Reveals Critical Role in Interaction with Phosphorylated Histone H2A during DNA Damage Repair*

    PubMed Central

    Li, Xinxin; Liu, Kaixian; Li, Fudong; Wang, Juncheng; Huang, Hongda; Wu, Jihui; Shi, Yunyu

    2012-01-01

    Rtt107 (regulator of Ty1 transposition 107; Esc4) is a DNA repair protein from Saccharomyces cerevisiae that can restore stalled replication forks following DNA damage. There are six BRCT (BRCA1 C-terminal) domains in Rtt107 that act as binding sites for other recruited proteins during DNA repair. Several Rtt107 binding partners have been identified, including Slx4, Rtt101, Rad55, and the Smc5/6 (structural maintenance of chromosome) protein complex. Rtt107 can reportedly be recruited to chromatin in the presence of Rtt101 and Rtt109 upon DNA damage, but the chromatin-binding site of Rtt107 has not been identified. Here, we report our investigation of the interaction between phosphorylated histone H2A (γH2A) and the C-terminal tandem BRCT repeats (BRCT5-BRCT6) of Rtt107. The crystal structures of BRCT5-BRCT6 alone and in a complex with γH2A reveal the molecular basis of the Rtt107-γH2A interaction. We used in vitro mutagenesis and a fluorescence polarization assay to confirm the location of the Rtt107 motif that is crucial for this interaction. In addition, these assays indicated that this interaction requires the phosphorylation of H2A. An in vivo phenotypic analysis in yeast demonstrated the critical role of BRCT5-BRCT6 and its interaction with γH2A during the DNA damage response. Our results shed new light on the molecular mechanism by which Rtt107 is recruited to chromatin in response to stalled DNA replication forks. PMID:22262834

  8. Abundance, diversity and functional gene expression of denitrifier communities in adjacent riparian and agricultural zones.

    PubMed

    Dandie, Catherine E; Wertz, Sophie; Leclair, Caissie L; Goyer, Claudia; Burton, David L; Patten, Cheryl L; Zebarth, Bernie J; Trevors, Jack T

    2011-07-01

    Lands under riparian and agricultural management differ in soil properties, water content, plant species and nutrient content and are therefore expected to influence denitrifier communities, denitrification and nitrous oxide (N(2) O) emissions. Denitrifier community abundance, denitrifier community structure, denitrification gene expression and activity were quantified on three dates in a maize field and adjacent riparian zone. N(2) O emissions were greater in the agricultural zone, whereas complete denitrification to N(2) was greater in the riparian zone. In general, the targeted denitrifier community abundance did not change between agricultural and riparian zones. However, nosZ gene expression was greater in the riparian zone than the agricultural zone. The community structure of nirS-gene-bearing denitrifiers differed in June only, whereas the nirK-gene-bearing community structure differed significantly between the riparian and the agricultural zones at all dates. The nirK-gene-bearing community structure was correlated with soil pH, while no significant correlations were found between nirS-gene-bearing community structure and soil environmental variables or N(2) O emissions, denitrification or denitrifier enzyme activity. The results suggested for the nirK and nirS-gene-bearing communities different factors control abundance vs. community structure. The nirK-gene-bearing community structure was also more responsive than the nirS-gene-bearing community structure to change between the two ecosystems.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. Coexistence Analysis of Adjacent Long Term Evolution (LTE) Systems

    SciTech Connect

    Aulama, Mohannad M.; Olama, Mohammed M

    2013-01-01

    As the licensing and deployment of Long term evolution (LTE) systems are ramping up, the study of coexistence of LTE systems is an essential topic in civil and military applications. In this paper, we present a coexistence study of adjacent LTE systems aiming at evaluating the effect of inter-system interference on system capacity and performance as a function of some of the most common mitigation techniques: frequency guard band, base station (BS) antenna coupling loss, and user equipment (UE) antenna spacing. A system model is constructed for two collocated macro LTE networks. The developed model takes into consideration the RF propagation environment, power control scheme, and adjacent channel interference. Coexistence studies are performed for a different combination of time/frequency division duplex (TDD/FDD) systems under three different guard-bands of 0MHz, 5MHz, and 10MHz. Numerical results are presented to advice the minimum frequency guard band, BS coupling loss, and UE antenna isolation required for a healthy system operation.

  14. SU-E-T-01: (In)dependence of Plan Quality On Treatment Modalities and Target-To-Critical Structure Geometry for Brain Tumor

    SciTech Connect

    Ruan, D; Shao, W; Low, D; Kupelian, P; Qi, S X

    2015-06-15

    Purpose: To evaluate and test the hypothesis that plan quality may be systematically affected by treatment delivery techniques and target-tocritical structure geometric relationship in radiotherapy for brain tumor. Methods: Thirty-four consecutive brain tumor patients treated between 2011–2014 were analyzed. Among this cohort, 10 were planned with 3DCRT, 11 with RadipArc, and 13 with helical IMRT on TomoTherapy. The selected dosimetric endpoints (i.e., PTV V100, maximum brainstem/chiasm/ optic nerve doses) were considered as a vector in a highdimensional space. A Pareto analysis was performed to identify the subset of Pareto-efficient plans.The geometric relationships, specifically the overlapping volume and centroid-of-mass distance between each critical structure to the PTV were extracted as potential geometric features. The classification-tree analyses were repeated using these geometric features with and without the treatment modality as an additional categorical predictor. In both scenarios, the dominant features to prognosticate the Pareto membership were identified and the tree structures to provide optimal inference were recorded. The classification performance was further analyzed to determine the role of treatment modality in affecting plan quality. Results: Seven Pareto-efficient plans were identified based on dosimetric endpoints (3 from 3DCRT, 3 from RapicArc, 1 from Tomo), which implies that the evaluated treatment modality may have a minor influence on plan quality. Classification trees with/without the treatment modality as a predictor both achieved accuracy of 88.2%: with 100% sensitivity and 87.1% specificity for the former, and 66.7% sensitivity and 96.0% specificity for the latter. The coincidence of accuracy from both analyses further indicates no-to-weak dependence of plan quality on treatment modality. Both analyses have identified the brainstem to PTV distance as the primary predictive feature for Pareto-efficiency. Conclusion: Pareto

  15. [Critical incidents].

    PubMed

    Scheidegger, D

    2005-03-01

    In medicine real severe mishaps are rare. On the other hand critical incidents are frequent. Anonymous critical incident reporting systems allow us to learn from these mishaps. This learning process will make our daily clinical work safer Unfortunately, before these systems can be used efficiently our professional culture has to be changed. Everyone in medicine has to admit that errors do occur to see the need for an open discussion. If we really want to learn from errors, we cannot punish the individual, who reported his or her mistake. The interest is primarily in what has happened and why it has happened and not who has committed this mistake. The cause for critical incidents in medicine is in over 80% the human factor Poor communication, work under enormous stress, conflicts and hierarchies are the main cause. This has been known for many years, therefore have already 15 years ago high-tech industries, like e.g. aviation, started to invest in special courses on team training. Medicine is a typical profession were until now only the individual performance decided about the professional career Communication, conflict management, stress management, decision making, risk management, team and team resource management were subjects that have never been taught during our preor postgraduate education. These points are the most important ones for an optimal teamwork. A multimodular course designed together with Swissair (Human Aspect Development medical, HADmedical) helps to cover, as in aviation, the soft factor and behavioural education in medicine and to prepare professionals in health care to work as a real team.

  16. 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.

  17. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2012-10-01 2012-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  18. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2010-10-01 2010-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  19. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2011-10-01 2011-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  20. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2013-10-01 2013-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  1. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2014-10-01 2014-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  2. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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...

  3. 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...

  4. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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...

  5. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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...

  6. 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

  7. 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.

  8. 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.

  9. Scolopendromorpha of New Guinea and adjacent islands (Myriapoda, Chilopoda).

    PubMed

    Schileyko, Arkady A; Stoev, Pavel E

    2016-08-04

    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.

  10. 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.

  11. Reconnaissance geologic map of Kodiak Island and adjacent islands, Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.

    2013-01-01

    Kodiak Island and its adjacent islands, located on the west side of the Gulf of Alaska, contain one of the largest areas of exposure of the flysch and melange of the Chugach terrane of southern Alaska. However, in the past 25 years, only detailed mapping covering small areas in the archipelago has been done. This map and its associated digital files (Wilson and others, 2005) present the best available mapping compiled in an integrated fashion. The map and associated digital files represent part of a systematic effort to release geologic map data for the United States in a uniform manner. The geologic data have been compiled from a wide variety of sources, ranging from state and regional geologic maps to large-scale field mapping. The map data are presented for use at a nominal scale of 1:500,000, although individual datasets (see Wilson and others, 2005) may contain data suitable for use at larger scales.

  12. 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

  13. Scale-dependent interactions between vegetation, landscape, and climate: How critical zone structure influences ecohydrological reslience in a rapidly changing world

    NASA Astrophysics Data System (ADS)

    Brooks, P. D.; Barnard, H. R.; Chorover, J.; Fan, Y.; Gallo, E. L.; Godsey, S.; Maxwell, R. M.; McNamara, J. P.; Swetnam, T. L.; Tague, N.

    2015-12-01

    Concurrent changes in climate, land cover, and population are pushing coupled human and natural systems outside of the historical range of natural variability, presenting major challenges to the management of natural and built environments worldwide. A comprehensive understanding of how precipitation is partitioned to ecosystem and societal water resources is central to many of these challenges. Although considerable progress has been made advancing process understanding and developing ecohydrological models, a key challenge remains applying this knowledge to landscape and regional scales of resource management. Approaches to address this challenge, ranging from deterministic to probabilistic models, all face the challenge of identifying scale breaks in the coupling between biotic and abiotic processes. We employ an alternative, complementary approach, combining newer observations (e.g. high resolution aerial LiDAR; isotopes) and established techniques to identify scale breaks and transitions in how ecological processes, occurring on relatively short timescales, are coupled to longer-term development of critical zone, that typically develops over longer time scales. At stand scales, vegetation structure strongly controls the fraction of precipitation partitioned to evaporation by influencing both solar radiation and turbulence with a net change in effective precipitation (water available for transpiration, recharge, or streamflow) of as much as 25%. At hillslope scales, topographic shading or exposure has similar magnitude effects on total evapotranspiration, while topographically driven water subsidy can double carbon storage through increases in both tree size and number. At catchment-scales, the coupling between vegetation, climate, and the physical landscape results in a predictable signature in hydrologic partitioning that reflects regional susceptibility to drought. Importantly, these transitions in biophysical interactions, occurring at scales from 0.01 to

  14. Genetic diversity and population structure of Nuphar submersa (Nymphaeaceae), a critically endangered aquatic plant endemic to Japan, and implications for its conservation.

    PubMed

    Shiga, Takashi; Yokogawa, Masashi; Kaneko, Shingo; Isagi, Yuji

    2017-01-01

    Nuphar submersa (Nymphaeaceae) is a critically endangered freshwater macrophyte indigenous to central Japan, with only four small extant populations represented across its entire range. We investigated the genotypic and genetic diversity as well as the genetic structure of all extant individuals of N. submersa based on analysis of 15 microsatellite loci. Among 278 individual ramets, 52 multilocus genotypes were detected: 30 genotypes in Nikko City (NIK), 18 in Nasukarasuyama City (NAS), 3 in Mooka City (MOK), and 1 in Sakura City (SAK). The average number of alleles per locus ranged from 1.20 to 1.93, whereas the observed and expected heterozygosities ranged from 0.11 to 0.33 and from 0.10 to 0.24, respectively. With the exception of SAK, all populations contained multiple clones, but our results indicated low levels of within-population genetic diversity. The populations NIK and NAS comprised few large or middle-sized genets and many small genets. The populations NIK and NAS were suggested to comprise large old, old fragmented, and/or young small genets resulting from seedling establishment. All four populations were differentiated, and gene flow between the populations was restricted (average level of gene flow (Nm) = 0.122, G' ST  = 0.639). Of the total genetic diversity, 67.20 and 9.13% were attributable to inter- and intra-population diversity, respectively. STRUCTURE analysis revealed two or three well-differentiated groups of populations. Cluster I comprised one population (NIK) and cluster II comprised the remaining populations at K = 2. The populations NIK, NAS, and the remaining populations were assigned to clusters I, II, and III, respectively, at K = 3. For conservation practices, we recommend that each cluster be regarded as a different management unit. We further suggest that artificial gene flow among MOK and SAK populations is an appropriate option, whereas NIK should not be reinforced with genotypes from the remaining populations.

  15. 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.

  16. Regional Jurassic geologic framework of Alabama coastal waters area and adjacent Federal waters area

    USGS Publications Warehouse

    Mink, R.M.; Bearden, B.L.; Mancini, E.A.

    1989-01-01

    To date, numerous Jurassic hydrocarbon fields and pools have been discovered in the Cotton Valley Group, Haynesville Formation, Smackover Formation and Norphlet Formation in the tri-state area of Mississippi, Alabama and Florida, and in Alabama State coastal waters and adjacent Federal waters area. Petroleum traps are basement highs, salt anticlines, faulted salt anticlines and extensional faults associated with salt movement. Reservoirs include continental and marine sandstones, limestones and dolostones. Hydrocarbon types are oil, condensate and natural gas. The onshore stratigraphic and structural information can be used to establish a regional geologic framework for the Jurassic for the State coastal waters and adjacent Federal waters areas. Evaluation of the geologic information along with the hydrocarbon data from the tri-state area indicates that at least three Jurassic hydrocarbon trends (oil, oil and gas condensate, and deep natural gas) can be identified onshore. These onshore hydrocarbon trends can be projected into the Mobile area in the Central Gulf of Mexico and into the Pensacola, Destin Dome and Apalachicola areas in the Eastern Gulf of Mexico. Substantial reserves of natural gas are expected to be present in Alabama State waters and the northern portion of the Mobile area. Significant accumulations of oil and gas condensate may be encountered in the Pensacola, Destin Dome, and Apalachicola areas. ?? 1989.

  17. 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

  18. 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

  19. Cu, Cr and As distribution in soils adjacent to pressure-treated decks, fences and poles.

    PubMed

    Chirenje, Tait; Ma, L Q; Clark, C; Reeves, M

    2003-01-01

    Chromated copper arsenate (CCA)-treated wood has been widely used in the Southeastern United States to protect wood products from microbial and fungal decay. The aims of this study were to (1). determine the distribution of arsenic (As), chromium (Cr), and copper (Cu), in soils surrounding CCA-treated wood structures such as decks, fences and poles; and (2). evaluate the impacts of these structures on As, Cr and Cu loading of the soils. Profile and lateral soil samples were collected under CCA-treated decks and adjacent to poles and fences. The results showed elevation of As, Cr and Cu concentrations close to and under the structures, with mean As concentrations as high as 23 mg x kg(-1) close to utility poles compared with less than 3 mg x kg (-1) at distances of about 1.5 m away. Concentrations of As, Cr, and Cu decreased with depth in areas close to CCA-treated poles. However, these results were only apparent in relatively new structures. A combination of weathering and leaching with time may have reduced the impact in older poles. Increased concentrations of As, Cu and Cr were also observed close to CCA-treated decks and fences, with age showing a similar impact. These results are helpful for CCA-treated wood product users to determine the safe use of these structures.

  20. 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

  1. 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

  2. TU-G-BRA-05: Predicting Volume Change of the Tumor and Critical Structures Throughout Radiation Therapy by CT-CBCT Registration with Local Intensity Correction

    SciTech Connect

    Park, S; Robinson, A; Kiess, A; Quon, H; Wong, J; Lee, J; Plishker, W; Shekhar, R

    2015-06-15

    can accurately predict the tumor volume change with reduced errors. Although demonstrated only on HN nodal GTVs, the results imply improved accuracy for other critical structures. This work was supported by NIH/NCI under grant R42CA137886.

  3. 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.

  4. Meiobenthos and nematode community in Yenisei Bay and adjacent parts of the Kara Sea shelf

    NASA Astrophysics Data System (ADS)

    Portnova, D. A.; Garlitska, L. A.; Udalov, A. A.; Kondar, D. V.

    2017-01-01

    Material is collected on a meridional profile from Yenisei Bay to adjacent parts of the Kara Sea shelf. The length of the profile is 550 km; 13 to 62 m depths. A multiple corer and Niemistö corer are used as sampling tools. The meiobenthos is represented by 13 taxa. Nematodes are the most abundant taxon, and harpacticoid copepods (Harpacticoida) are subdominant. The abundance and taxonomic diversity of meiobenthos and nematodes increases from the freshwater part of Yenisei Bay towards the Kara Sea shelf. Three types of taxocene are distinguished: freshwater, brackish-water, and marine. The taxocene of the estuary is not distinguished by any specific set of species and consists of species characteristic of the nematode community both in the freshwater and marine zones. The trophic structure of the taxocene of nematodes in Yenisei Bay is dominated by nematodes with well-defined stoma and are differently armed. The estuary and shelf are dominated by selective and nonselective deposit feeders.

  5. 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

  6. Electron microscopic analysis of synaptic inputs from the median preoptic nucleus and adjacent regions to the supraoptic nucleus in the rat.

    PubMed

    Armstrong, W E; Tian, M; Wong, H

    1996-09-16

    The median preoptic nucleus (MnPo) is critical for normal fluid balance, mediating osmotically evoked drinking and neurohypophysial hormone secretion. The influence of the MnPo on vasopressin and oxytocin release is in part through direct connections to the supraoptic and paraventricular nucleus. In the present investigation the synaptic contacts between the MnPo and supraoptic neurons were investigated in rats by ultrastructural examination of terminals labeled anterogradely with the tracers Phaseolus vulgaris-leucoagglutinin or biotinylated dextran. At the light microscopic level, labeled fibers within the supraoptic nucleus branched frequently, were punctuated by varicosities, and were distributed throughout the nucleus without preference for the known distributions of oxytocin and vasopressin neurons. At the ultrastructural level, synapses were associated with many of these varicosities. The ratio of labeled axodendritic to axosomatic synapses encountered was roughly consistent with a uniform innervation of dendrites and somata. The great majority of synapses were characterized by symmetrical contacts. Similar results were found for a few injections made in the organum vasculosum of the lamina terminalis, just rostral to the MnPo, and in the immediately adjacent periventricular preoptic area. Coupled with other recent anatomical and electrophysiological evidence, these results suggest there is a strong monosynaptic pathway from structures along the ventral lamina terminalis to the supraoptic nucleus.

  7. Tissue microenvironments within functional cortical subdivisions adjacent to focal stroke.

    PubMed

    Katsman, Diana; Zheng, Jian; Spinelli, Kateri; Carmichael, S Thomas

    2003-09-01

    Stroke produces a region of complete cell death and areas of partial damage, injury, and gliosis. The spatial relationship of these regions of damage to the infarct core and within spared neuronal circuits has not been identified. A model of cortical stroke was developed within functional subsets of the somatosensory cortex. Infarct size, regions of apoptosis, oxidative DNA damage, heat shock protein induction, and subtypes of reactive gliosis were precisely mapped with the somatosensory body map, quantified, and interrelated. Three tissue microenvironments were recognized: zones of partial ischemic damage, heat shock protein induction, and distributed gliosis. These three zones involved progressively more distant cortical regions, each larger than the infarct core. The zone of partial ischemic damage represents an overlap region of apoptotic cell death, oxidative DNA damage, loss of synaptic connections, and local reactive gliosis. The zone of distributed gliosis occupies distinct functional areas of the somatosensory cortex. The tissue reorganization induced by stroke is much larger than the stroke site itself. Adjacent tissue microenvironments are sites of distinct reactive cellular signaling and may serve as a link between the processes of acute cell death and delayed neuronal plasticity after focal stroke.

  8. Light scattering by adjacent red blood cells: a mathematical model

    NASA Astrophysics Data System (ADS)

    Uzunoglou, Nikolaos K.; Stamatakos, Georgios; Koutsouris, Dimitrios; Yova-Loukas, Dido M.

    1995-01-01

    Simple approximate scattering theories such as the Rayleigh-Gans theory are not generally applicable to the case of light scattering by red blood cell (RBC) aggregates, including thrombus. This is mainly due to the extremely short distance separating erythrocytes in the aggregates (of the order of 25 nm) as well as to the substantial size of the aggregates. Therefore, in this paper a new mathematical model predicting the electromagnetic field produced by the scattering of a plane electromagnetic wave by a system of two adjacent RBCs is presented. Each RBC is modeled as a homogeneous dielectric ellipsoid of complex index of refraction surrounded by transparent plasma. The relative position and orientation of the ellipsoids are arbitrary. Scattering is formulated in terms of an integral equation which, however, contains two singular kernels. The singular equation is transformed into a pair of nonsingular integral equations for the Fourier transform of the internal field of each RBC. The latter equations are solved by reducing them by quadrature into a matrix equation. The resulting solutions are used to estimate the scattering amplitude. Convergence aspects concerning the numerical calculation of the matrix elements originating from the interaction between the RBCs are also presented.

  9. Congenital stenosis and adjacent segment disease in the cervical spine.

    PubMed

    Eubanks, Jason David; Belding, Jon; Schnaser, Erik; Rowan, Andrew; Moffitt, Gable; Weaver, John; Reich, Michael S; Bechtel, Chris; Xie, Ke; Gande, Abhiram; Hohl, Justin; Braly, Brett; Hilibrand, Alan; Kang, James D

    2013-10-01

    Symptomatic adjacent segment disease (ASD) after anterior cervical fusion (ACF) is reported in 25% of patients at 10 years postoperatively. Debate continues as to whether this degeneration is due to the natural history of the disk or the changed biomechanics after ACF. This study explored whether congenital stenosis predisposes patients to an increased incidence of ASD after ACF. A retrospective review of 635 patients with myelopathy or radiculopathy was performed; 364 patients had complete records for review. Patients underwent 1- to 5-level ACF (94 one-level, 145 two-level, 79 three-level, 45 four-level, and 1 five-level). Radiographs were evaluated for bony congenital stenosis using validated parameters, and ASD was measured according to Hilibrand's criteria and correlated with symptomatic ASD. Congenital stenosis was found in 21.7% of patients and radiographic ASD in 33.5%, with a significant association between these parameters. However, symptomatic ASD occurred in 11.8% of patients; no association between congenital stenosis and symptomatic ASD or myelopathy and ASD was found. Clinical results demonstrated excellent or good Robinson scores in 86.2% of patients and Odom scores in 87% of patients. Despite mostly excellent to good outcomes, symptomatic ASD is common after ACF. Although congenital stenosis appears to increase the incidence of radiographic ASD, it does not appear to predict symptomatic ASD.

  10. The hydraulics of exchange flow between adjacent confined building zones

    NASA Astrophysics Data System (ADS)

    Nabi, Saleh; Flynn, Morris

    2012-11-01

    Buoyancy-driven flow between two finite zones containing fluid of slightly different density is investigated. The two zones are connected through a common opening that spans the channel width so that a two layer exchange flow develops once it is removed. In the zone that initially contained dense fluid, a buoyant plume of light fluid mixes with the dense fluid leading, over time, to the development of a nontrivial ambient density stratification. Meanwhile, dense fluid flows as a gravity current into the zone that initially contained light fluid. This gravity current reflects from the end wall and propagates back toward the opening in the form of an internal bore. When the bore reaches the opening, the dynamics of the exchange flow (and consequently the source conditions of the buoyant plume) are substantially altered. Such dynamics are modeled by combining elements of gravity current, internal bore, plume and exchange flow theory; model predictions, such as that the density jump across the first front steadily decreases once the exchange flow becomes transient, are corroborated by salt-bath laboratory experiments. Substantially different predictions arise when either or both of the adjacent zones are assumed to be well-mixed so that no vertical gradient of density is allowed.

  11. 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.

  12. Alteration-weakening leading to localized deformation in a damage aureole adjacent to a dormant shear zone

    NASA Astrophysics Data System (ADS)

    Backeberg, Nils R.; Rowe, Christie D.; Barshi, Naomi

    2016-09-01

    Deformation adjacent to faults and shear zones is traditionally thought to correlate with slip. Inherited structures may control damage geometry, localizing fluid flow and deformation in a damage aureole around structures, even after displacement has ceased. In this paper we document a post-shearing anastomosing foliation and fracture network that developed to one side of the Mesoarchean Marmion Shear Zone. This fracture network hosts the low-grade, disseminated Hammond Reef gold deposit. The shear zone juxtaposed a greenstone belt against tonalite gneiss and was locked by an intrusion that was emplaced during the final stages of suturing. After cessation of activity, fluids channeled along fault- and intrusion-related fractures led to the pervasive sericitization of feldspars. Foliated zones resulted from flattening in the weaker sericite-rich tonalite during progressive alteration without any change in the regional NW-SE shortening direction. The anastomosing pattern may have been inherited from an earlier ductile fabric, but sericite alteration and flattening fabrics all formed post-shearing. Thus, the apparent foliated fracture network adjacent to the Marmion Shear Zone is a second-order effect of shear-related damage, distinct in time from shear activity, adjacent to an effectively dormant shear zone. This phenomenon has implications for understanding the relative timing of fault zone activity, alteration and (in this case) gold mineralization related to long-term fault zone permeability.

  13. 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.

  14. 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.

  15. Calcium-catalyzed asymmetric synthesis of 3-tetrasubstituted oxindoles: efficient construction of adjacent quaternary and tertiary chiral centers.

    PubMed

    Shimizu, Shota; Tsubogo, Tetsu; Xu, Pengyu; Kobayashi, Shū

    2015-04-17

    Chiral Ca-catalyzed asymmetric addition reactions of 3-substituted oxindoles with N-Boc-imines afford 3-tetrasubstituted oxindole derivatives bearing adjacent quaternary and tertiary chiral centers, which are key structures for biological activities. Ubiquitous and nontoxic Ca catalysts (1-10 mol %) work well in this reaction, and high yields (up to 99%) and selectivities (up to >99% ee) of the products with wide substrate scope have been attained. The structures of the chiral Ca catalysts and intermediary Ca enolates are also discussed.

  16. Platelets in Critical Illness.

    PubMed

    Levi, Marcel

    2016-04-01

    In patients with critical illness, thrombocytopenia is a frequent laboratory abnormality. However frequent this may occur, a low platelet count is not an epiphenomenon, but a marker with further significance. It is always important to assess the proper cause for thrombocytopenia in critically ill patients because different underlying disorders may precipitate different diagnostic and therapeutic management strategies. Platelets are part of the first-line defense of the body against bleeding; hence, thrombocytopenia may increase the risk of hemorrhage. In case of systemic inflammatory syndromes, such as the response to sepsis, disseminated intravascular platelet activation may occur. This will contribute to microvascular failure and thereby play a role in the development of organ dysfunction. Platelets are circulating blood cells that will normally not interact with the intact vessel wall but that may swiftly respond to endothelial disruption (which is often part of the pathogenesis of critical illness) by adhering to subendothelial structures, followed by interaction with each other, thereby forming a platelet aggregate. The activated platelet (phospholipid) membrane may form a suitable surface on which further coagulation activation may occur. A low platelet count is a strong and independent predictor of an adverse outcome in critically ill patients, thereby facilitating a simple and practically risk assessment in these patients and potentially guiding the use of complex or expensive treatment strategies.

  17. 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.

  18. 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…

  19. Mammalian enabled (Mena) is a critical regulator of cardiac function.

    PubMed

    Aguilar, Frédérick; Belmonte, Stephen L; Ram, Rashmi; Noujaim, Sami F; Dunaevsky, Olga; Protack, Tricia L; Jalife, Jose; Todd Massey, H; Gertler, Frank B; Blaxall, Burns C

    2011-05-01

    Mammalian enabled (Mena) of the Drosophila enabled/vasodilator-stimulated phosphoprotein gene family is a cytoskeletal protein implicated in actin regulation and cell motility. Cardiac Mena expression is enriched in intercalated discs (ICD), the critical intercellular communication nexus between adjacent muscle cells. We previously identified Mena gene expression to be a key predictor of human and murine heart failure (HF). To determine the in vivo function of Mena in the heart, we assessed Mena protein expression in multiple HF models and characterized the effects of genetic Mena deletion on cardiac structure and function. Immunoblot analysis revealed significant upregulation of Mena protein expression in left ventricle tissue from patients with end-stage HF, calsequestrin-overexpressing mice, and isoproterenol-infused mice. Characterization of the baseline cardiac function of adult Mena knockout mice (Mena(-/-)) via echocardiography demonstrated persistent cardiac dysfunction, including a significant reduction in percent fractional shortening compared with wild-type littermates. Electrocardiogram PR and QRS intervals were significantly prolonged in Mena(-/-) mice, manifested by slowed conduction on optical mapping studies. Ultrastructural analysis of Mena(-/-) hearts revealed disrupted organization and widening of ICD structures, mislocalization of the gap junction protein connexin 43 (Cx43) to the lateral borders of cardiomyoycytes, and increased Cx43 expression. Furthermore, the expression of vinculin (an adherens junction protein) was significantly reduced in Mena(-/-) mice. We report for the first time that genetic ablation of Mena results in cardiac dysfunction, highlighted by diminished contractile performance, disrupted ICD structure, and slowed electrical conduction.

  20. Critical Configurations of Hard Disks on the Torus

    SciTech Connect

    Mason, J.

    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.