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We explore the connections between crustal shortening, volcanism, and mantle dynamics in the Atlas of Morocco. In response to compressional forces and strain localization, this intraplate orogen has evolved far from convergent plate margins. Convective effects, such as lithospheric weakening and plume‐related volcanism, contributed in important ways to the building of high topography. We seek to better understand how crustal and mantle processes interacted during the Atlas' orogeny by combining multiple strands of observations, including new and published data. Constraints on crustal and thermal evolution are combined with new analyses of topographic evolution, petrological, and geochemical data from the Anti‐Atlas volcanic fields, and a simple numerical model of the interactions among crustal deformation, a mantle plume, and volcanism. Our findings substantiate that: (a) crustal deformation and exhumation accelerated during the middle/late Miocene, contemporaneous with the onset of volcanism; (b) volcanism has an anorogenic signature with a deep source; (c) a dynamic mantle upwelling supports the high topography. We propose that a mantle plume and the related volcanism weakened the lithosphere beneath the Atlas and that this favored the localization of crustal shortening along pre‐existing structures during plate convergence. This convective‐tectonic sequence may represent a general mechanism for the modification of continental plates throughout the thermo‐chemical evolution of the supercontinental cycle. Key Points: Crustal thickening is limited and cannot account for the topography elevation of the Atlas systemResumption of volcanism is contemporaneous with the acceleration of crustal deformation and topography growingThe erosion and weakening of the lower lithosphere, as a consequence of mantle plume, may enhance crustal deformation and exhumation [ABSTRACT FROM AUTHOR]

During the second half of the XIX century, several species of red wood ants (Formica rufa group) were used as biological control agents and introduced to the Italian Apennine mountains where they were formerly absent. Among these, Formica lugubris was the most widely introduced alien species. In 1996, however, a taxonomic revision defined two sibling species, F. lugubris and F. paralugubris, each with distinct ecological and behavioural characteristics that differently affect their spatial distribution. The first one can be both monodomous and polydomous with a low number of interlinked nests, and it is obliged to mate by nuptial flight. Conversely, F. paralugubris is usually unicolonial, with a considerable portion of intranest mates. Discrimination between the two species using morphological characters is possible but requires considerable taxonomic expertise. Restriction analysis, whereby presence/absence of a BamHI site in the mitochondrial DNA COI gene results in different restriction profiles, provides an alternative efficient method to unambiguously distinguish F. lugubris from F. paralugubris. We applied this method to identify ant species introduced to several locations in the Campigna Forest of the Foreste Casentinesi, Monte Falterona and Campigna National Park, one of the Italian locations mostly affected by alien ant introductions. This area has considerable ecological relevance. Given the potential impact of ants on native arthropod communities, it is of the most importance to identify which species has been introduced. Contrary to previous assumptions, results of our analysis clearly show that only F. paralugubris is present in the National park. [ABSTRACT FROM AUTHOR]

The Adige River flows from the Eastern Alps to the Adriatic Sea and the understanding of its fluvial dynamics can be improved by geochemical and O-H isotopic investigation. The most negative isotopic compositions are recorded close to the source (δO between −14.1 and −13.8 ‰, δD between −100.3 and −97.0 ‰), and δD and δO values generally increase downstream through the upper part (UP, the mountainous sector), stabilizing along the lower part (LP, the alluvial plain) of the river with δO between −12.4 and −11.8 ‰, δD between −86.9 and −83.7 ‰. The isotopic variations along the stream path (δO-δD vs distance from the source) depict subparallel distributions for all the investigated periods, with less negative values recorded in winter. Total dissolved solids (TDS) concentration shows the lowest value (<100 mg/l) at the river source, jumping to 310 mg/l at the Rio Ram inflow, then decreasing down to the Isarco River confluence; from here, we observed an increase toward the river mouth, with different values in the distinct sampling periods. The lowest values (140-170 mg/l) were recorded during high discharge in spring, whereas higher TDS values (up to 250 mg/l) were recorded during winter low flow conditions. Extreme TDS values were observed in the estuarine samples (up to 450 mg/l), as result of mixing with seawater. The results allow for the identification of distinct water end-members: glacio-nival component(s) characterized by the most negative isotopic composition and extremely low TDS, a rainfall component characterized by intermediate isotopic and elemental composition and groundwater characterized by the less negative isotopic composition and comparatively higher TDS. An additional component is represented by seawater, which is recorded at the lowest reach of the river during drought periods. These contributions variously mix along the stream path in the distinct hydrological periods, and the presented data are a snapshot of the current hydroclimatic conditions. Future investigations will evaluate possible hydrological variations related to meteo-climatic changes. Monitoring is fundamental for future water management to overcome the vanishing of a significant water end-member of the basin, i.e., the glacio-nival reservoir that is severely affected by the ongoing climatic changes. [ABSTRACT FROM AUTHOR]

The Axum-Adwa igneous complex consists of a basalt-trachyte (syenite) suite emplaced at the northern periphery of the Ethiopian plateau, after the paroxysmal eruption of the Oligocene (ca 30 Ma) continental flood basalts (CFB), which is related to the Afar plume activity. Ar/Ar and K-Ar ages, carried out for the first time on felsic and basaltic rocks, constrain the magmatic age of the greater part of the complex around Axum to 19-15 Ma, whereas trachytic lavas from volcanic centres NE of Adwa are dated ca 27 Ma. The felsic compositions straddle the critical SiO-saturation boundary, ranging from normative quartz trachyte lavas east of Adwa to normative (and modal) nepheline syenite subvolcanic domes (the obelisks stones of ancient axumites) around Axum. Petrogenetic modelling based on rock chemical data and phase equilibria calculations by PELE (Boudreau ) shows that low-pressure fractional crystallization processes, starting from mildly alkaline- and alkaline basalts comparable to those present in the complex, could generate SiO-saturated trachytes and SiO-undersaturated syenites, respectively, which correspond to residual liquid fractions of 17 and 10 %. The observed differentiation processes are consistent with the development of rifting events and formation of shallow magma chambers plausibly located between displaced (tilted) crustal blocks that favoured trapping of basaltic parental magmas and their fractionation to felsic differentiates. In syenitic domes, late- to post-magmatic processes are sometimes evidenced by secondary mineral associations (e.g. Bete Giorgis dome) which overprint the magmatic parageneses, and mainly induce additional nepheline and sodic pyroxene neo-crystallization. These metasomatic reactions were promoted by the circulation of Na-Cl-rich deuteric fluids (600-400 °C), as indicated by mineral and bulk rock chemical budgets as well as by δO analyses on mineral separates. The occurrence of this magmatism post-dating the CFB event, characterized by comparatively lower volume of more alkaline products, conforms to the progressive vanishing of the Afar plume thermal effects and the parallel decrease of the partial melting degrees of the related mantle sources. This evolution is also concomitant with the variation of the tectono-magmatic regime from regional lithospheric extension (CFB eruption) to localized rifting processes that favoured magmatic differentiation. [ABSTRACT FROM AUTHOR]

In this paper a robotic means of magnetic navigation of an endovascular device a few millimeters in diameter is presented. The technique, based on traditional computer-assisted surgery adapted to intravascular medical procedures, includes a manipulator for magnetic dragging interfaced with an ultrasound system for tracking the endovascular device. The main factors affecting device propulsion are theoretically analyzed, including magnetic forces, fluidic forces, and friction forces between the endovascular device and the vessel. A dedicated set-up for measuring locomotion, and for navigation with and against the flow, has been developed and preliminary tests have been performed to derive the best configuration for controlled magnetic dragging in the vascular system. Experimental outcomes are consistent with a simple analytical model that analyzes dragging of the magnetic capsule in a tube. By means of this model, different working conditions can be considered to select the appropriate conditions, for example flow rate, coefficient of friction, or magnetic properties. [ABSTRACT FROM AUTHOR]

Using qualitative data from Ghana, this article explores the role of information in the formation of expectations of migrants and their families back home, with specific reference to the return experience. We develop a typology to illustrate (1) how information influences expectations throughout the migration experience; (2) the ability of the migrant and their family to adapt to those changing expectations, given differing levels of information; and (3) the implications (1) and (2) have for return. Latent tensions and conflicts emerge in which expectations of migrants and migrant families are not harmonious. The evidence shows that the pace of adaptation and change is regulated by access to information; information flow between migrant at destination and home; and the propensity of the migrant to adapt, which is related to the level of financial dependency (or strength of obligation) between migrant and home. The article raises policy questions around information access and information flows, community sensitisation and returnee reintegration, especially in poorer areas.Cet article utilise des données qualitatives sur le Ghana pour étudier le rôle que joue l’information dans la formation des attentes des migrants et de leurs familles, en ciblant plus particulièrement l’expérience du retour. Nous développons une typologie dans le but d’illustrer (1) comment l’information détermine les attentes dans le cas de l’expérience migratoire, (2) la capacité des migrants et de leurs familles à s’adapter à de nouvelles attentes dues à des niveaux d’information différents; et (3) les conséquences que les deux premiers points peuvent avoir sur les conditions du retour. Des tensions latentes se manifestent et des conflits émergent quand les attentes des migrants et de leurs familles ne vont pas dans le même sens. Les témoignages montrent que le rythme d’adaptation et de changement est régulé par l’accès à l’information, que l’information circule entre les migrants arrivés à destination et le pays d’origine, et que la propension des migrants à s’adapter est liée au niveau de dépendance financière (ou au poids des obligations) entre les migrants et le pays d’origine. L’article soulève des questions à propos de l’accès à l’information et les flux d’information, la sensibilisation des communautés, et la réintégration de ceux qui sont de retour, plus particulièrement dans les régions pauvres. [ABSTRACT FROM AUTHOR]

Objectives: To illustrate the CT and MRI features of spinal osteoblastomas and correlate the imaging with histological findings.Design: In a retrospective review the CT and MRI features of spinal osteoblastomas with respect to mineralisation, signal intensity (SI), adjacent reactive changes, enhancement following gadolinium-DTPA (5 cases) and adjacent soft tissue masses were compared and correlated with the histological findings including the degree of osteoid formation and matrix mineralisation, vascularity and surrounding reactive changes in bone and soft tissue.Patients: Eleven patients (7 males and 4 females; age range 8-43 years, mean age 19.5 years) with 12 osteoblastomas (1 patient suffered a recurrence) were studied.Results: All lesions showed classical features on CT with varying degrees of matrix mineralisation, whereas MRI identified mineralisation in only eight of 12 cases. MRI showed low signal intensity of the lesion on both T1- and T2-weighted sequences in several cases in the absence of heavy mineralisation. In these cases, histological examination revealed diffuse osteoid production by the tumour. All patients given gadolinium showed enhancement within the tumour on MRI. Reactive bone marrow changes were identified on MRI in 10 cases, and in five of these the changes were at multiple levels. An adjacent soft tissue mass was demonstrated in five cases, but extraosseous tumour was present histologically in only two of these.Conclusions: The MRI appearances of spinal osteoblastomas are varied and show no characteristic features. MRI may also overestimate the extent of the lesion due to extensive reactive changes and adjacent soft tissue masses. CT should continue to be the investigation of choice for the characterisation and local staging of suspected spinal osteoblastomas. [ABSTRACT FROM AUTHOR]

Objective: To illustrate the variety of paravertebral muscle abnormalities as seen on computed tomography (CT) or magnetic resonance imaging (MRI) in association with spinal osteoblastomas and correlate the findings with the presence of scoliosis.Design: In a retrospective study the clinical notes, plain radiographic, CT and/or MRI features were reviewed for the presence of scoliosis and paravertebral muscle abnormality (either inflammation or atrophy).Patients: Twelve patients (7 male, 5 female) with a mean age of 17 years were studied. Three lesions occurred in the cervical spine, five in the thoracic spine and four in the lumbar spine.Results and Conclusions: Nine patients had scoliosis. All patients with a thoracic or lumbar lesion and scoliosis (n = 8) had an associated abnormality of the paravertebral muscles (usually atrophy with fatty replacement). One patient with a lumbar lesion and no scoliosis had normal paravertebral muscles. One patient with a cervical lesion had thoracic scoliosis but no muscle abnormality in the cervical region, while two patients with cervical lesions and no scoliosis showed muscle abnormalities. The results support the clinical hypothesis that scoliosis in patients with spinal osteoblastoma is due to paravertebral muscle spasm, although this would not appear to be the case for cervical lesions. [ABSTRACT FROM AUTHOR]

Active locomotion of wireless capsule endoscopes has the potential to improve the diagnostic yield of this painless technique for the diagnosis of gastrointestinal tract disease. In order to design effective locomotion mechanisms, a quantitative measure of the propelling force required to effectively move a capsule inside the gastrointestinal tract is necessary. In this study, we introduce a novel wireless platform that is able to measure the force opposing capsule motion, without perturbing the physiologic conditions with physical connections to the outside of the gastrointestinal tract. The platform takes advantage of a wireless capsule that is magnetically coupled with an external permanent magnet. A secondary contribution of this manuscript is to present a real-time method to estimate the axial magnetic force acting on a wireless capsule manipulated by an external magnetic field. In addition to the intermagnetic force, the platform provides real-time measurements of the capsule position, velocity, and acceleration. The platform was assessed with benchtop trials within a workspace that extends 15 cm from each side of the external permanent magnet, showing average error in estimating the force and the position of less than 0.1 N and 10 mm, respectively. The platform was also able to estimate the dynamic behavior of a known resistant force with an error of 5.45%. Finally, an in vivo experiment on a porcine colon model validated the feasibility of measuring the resistant force in opposition to magnetic propulsion of a wireless capsule. [ABSTRACT FROM AUTHOR]