Search

Morphometric similarity networks (MSNs) estimate organization of the cortex as a biologically meaningful set of similarities between anatomical features at the macro- and microstructural level, derived from multiple structural MRI (sMRI) sequences. These networks are clinically relevant, predicting 40% variance in IQ. However, the sequences required (T1w, T2w, DWI) to produce these networks are longer acquisitions, less feasible in some populations. Thus, estimating MSNs using features from T1w sMRI is attractive to clinical and developmental neuroscience. We studied whether reduced-feature approaches approximate the original MSN model as a potential tool to investigate brain structure. In a large, homogenous dataset of healthy young adults (from the Human Connectome Project, HCP), we extended previous investigations of reduced-feature MSNs by comparing not only T1w-derived networks, but also additional MSNs generated with fewer MR sequences, to their full acquisition counterparts. We produce MSNs that are highly similar at the edge level to those generated with multimodal imaging; however, the nodal topology of the networks differed. These networks had limited predictive validity of generalized cognitive ability. Overall, when multimodal imaging is not available or appropriate, T1w-restricted MSN construction is feasible, provides an appropriate estimate of the MSN, and could be a useful approach to examine outcomes in future studies.

Flies were collected by sweep net from the vicinity of two small groups of "backyard" poultry (10-20 chickens per group) that had been identified as infected with exotic Newcastle disease virus (family Paramyxoviridae, genus avulavirus, ENDV) in Los Angeles County, CA, during the 2002-2003 END outbreak. Collected flies were subdivided into pools and homogenized in brain-heart infusion broth with antibiotics. The separated supernatant was tested for the presence of ENDV by inoculation into embryonated chicken eggs. Exotic Newcastle disease virus was isolated from pools of Phaenicia cuprina (Wiedemann), Fannia canicularis (L.), and Musca domestica L., and it was identified by hemagglutination inhibition with Newcastle disease virus antiserum. Viral concentration in positive pools was low (

For geosynthetic reinforced column supported embankments (GRCSE) supporting a high embankment, lateral forces associated with lateral sliding and embankment stability often govern the acceptability of a given design under serviceability conditions. Frequently, the complex soil-structure-geosynthetic interaction, the size, and the three- dimensional nature of a GRCSE necessitate the use of numerical analysis to assess embankment performance relative to serviceability criteria. However, traditional finite element method techniques used to model serviceability behaviour are limited in their ability to model the geotechnical mechanisms associated with column installation, equilibration, and group installation effects. These installation effects are examined herein based on a GRCSE field case study located in Melbourne, Australia, that has been extensively instrumented. The role that these installation effects have on the performance of the GRCSE is highlighted and the behaviour of the columns supporting the embankment is emphasized. It is shown that cracking of the unreinforced columns supporting the embankment is likely inevitable and that the reduction of lateral resistance provided by the columns should be accounted for in design. The suitability of various numerical approaches currently used in design to model the columns supporting the GRCSE, and the embankment itself, are discussed and recommendations are made. Key words: geosynthetic, field case study, column-supported embankment, installation effects. Pour les remblais colonne renforcee aux geosynthetiques (<>), soutenir un haut talus, les forces laterales associees au glissement lateral et la stabilite du remblai regissent souvent l'acceptabilite de la conception etant sous conditions de maintenance. Frequemment, l'interaction complexe sol- structure-geosynthetique, la taille et la nature tridimensionnelle d'un GRCSE necessite l'utilisation d'analyse numerique pour evaluer le rendement de remblais par rapport aux criteres de maintenance. Cependant, les techniques traditionnelles d'elements finis utilises pour modeliser le comportement de maintenance sont limitees dans leur capacite a modeliser les mecanismes geotechniques associes a l'installation de colonne, l'equilibre et les effets d'installation du groupe. Ces effets sont examines dans le present document et sont fondes sur une etude de cas sur le terrain GRCSE situe a Melbourne, en Australie, qui a ete largement instrumente. Le role que ces effets d'installation ont sur la performance de GRCSE est mis en evidence et le comportement des colonnes soutenant le talus est souligne. Il est demontre que la fissuration des murs colonnes soutenant le remblai est probablement inevitable et que la reduction de la resistance laterale fournie par les colonnes doit etre prise en compte dans la conception. La pertinence des differentes approches numeriques actuellement utilisee dans le modele de conception de colonnes soutenant le GRCSE, et le remblai lui- meme sont discutes et des recommandations sont formulees. [Traduit par la Redaction] Mots-cles: geosynthetique, etude de cas sur le terrain, remblai soutenu par colonne, effets d'installation., Introduction The design of geosynthetic reinforced column supported embankments (GRCSEs) requires the consideration of a number of limit state conditions. These typically include, but are not limited to, the following: [...]

Post-construction data from an instrumented geosynthetic reinforced column supported embankment (GRCSE) on drilled displacement columns in Melbourne, Australia, show the time-dependent development of arching over the 2 year monitoring period and a strong relationship between the development of arching stresses and subsoil settlement. A ground reaction curve is adopted to describe the development of arching stresses and good agreement is found for the period observed thus far. Predictions of arching stresses and load-transfer platform behaviour are presented for the remaining design life. Four phases of arching stress development (initial, maximum, load-recovery, and creep strain phases) are shown to describe the time-dependent, and subsoil-dependent, development of arching stresses that can be expected to occur in many field embankments. Of the four phases, the load-recovery phase is the most important with respect to load-transfer platform design, as it predicts the breakdown of arching stresses in the long term due to increasing subsoil settlement. This has important implications in assessing the appropriate design stress for the geosynthetic reinforcement layers, but also the deformation of the load-transfer platform in the long term. Key words: arching, geosynthetics, load-transfer platform, column-supported embankment, field case study. Les donnees apres la construction d'une colonne renforcee de maniere geosynthetique instrumentee sur du remblai (GRCSE) soutenu sur les colonnes a deplacement fore a Melbourne, Australie, montrent l'evolution dans le temps du developpement de l'effet de voute sur la periode de surveillance de deux annees et une relation forte entre le developpement de contrainte de l'effet de voute et le tassement du sous-sol. Une courbe de reaction du terrain est adoptee pour decrire le developpement de grandes contraintes de l'effet de voute et un bon accord est trouve pour la periode observee jusqu'a present. Les predictions de contraintes de l'effet de voute et du comportement de la plate-forme de transfert de charge sont presentees pour le reste de la duree de vie theorique. Quatre phases de developpement de contraintes de l'effet de voute (la phase initiale, maximum, reprise du chargement et deformation due au fluage) sont indiquees pour decrire l'evolution de contraintes de l'effet de voute en temps, et dans le sous-sol, qui peut se produire dans de nombreux remblais. Des quatre phases, la phase de reprise de charge est la plus importante en ce qui a trait a la conception de la plate-forme de transfert de charge, car elle prevoit l'effondrement des contraintes a long terme en raison de l'augmentation du tassement du sous-sol. Ceci a des implications importantes dans l'evaluation de la contrainte admissible appropriee pour les couches de renforcement geosynthetique, mais aussi la deformation de la plate-forme de transfert de charge a long terme. [Traduit par la Redaction] Mots-cles: effet de voute, geosynthetiques, plate-forme de transfert de charge, remblai soutenu par la colonne, etude de cas sur le terrain., Introduction Ground improvement using geosynthetic reinforcement and column supported embankments (GRCSEs) is an increasingly popular design solution to support embankments for road and rail applications. A significant quantity of research [...]