Improved segmentation of deep brain grey matter structures using magnetization transfer (MT) parameter maps.

Basal ganglia and brain stem nuclei are involved in the pathophysiology of various neurological and neuropsychiatric disorders. Currently available structural T1-weighted (T1w) magnetic resonance images do not provide sufficient contrast for reliable automated segmentation of various subcortical grey matter structures. We use a novel, semi-quantitative magnetization transfer (MT) imaging protocol that overcomes limitations in T1w images, which are mainly due to their sensitivity to the high iron content in subcortical grey matter. We demonstrate improved automated segmentation of putamen, pallidum, pulvinar and substantia nigra using MT images. A comparison with segmentation of high-quality T1w images was performed in 49 healthy subjects. Our results show that MT maps are highly suitable for automated segmentation, and so for multi-subject morphometric studies with a focus on subcortical structures.

Registered Flexible Fuel Vehicles

Iowa Code section 452A.33(3) requires a report regarding flexible fuel vehicles registered in Iowa. The report includes the number of flexible fuel vehicles according to year of manufacture; the number of passenger vehicles according to the year of manufacture; and the number of light pickup trucks according to the year of manufacture.

An ultrastructural approach to analogies between fungal structures and needle fibre calcite

Needle fiber calcite (NFC) is an ubiquitous terrestrial secondary calcium carbonate mineral often associated with calcitic nanofibers. NFC's origin has been debated for a long time and a fungal origin is often proposed. Fungi are known to be involved in mineral weathering and production of metal oxalate, but little information exists regarding the genesis of other minerals, such as calcite. In this study, a comparison of similar ultrastructural characteristics of fungal hyphae and NFC has been performed to highlight analogies between both features. These analogies clearly demonstrate the probable close relationship between fungal filaments (hyphae and rhizomorphs) and NFC and its associated nanofibers.

Dynamics of transient domain structures in nematic liquid crystals: The splay Fréedericksz transition

We discuss the dynamics of the transient pattern formation process corresponding to the splay Fréedericksz transition. The emergence and subsequent evolution of the spatial periodicity is here described in terms of the temporal dependence of the wave numbers corresponding to the maxima of the structure factor. Situations of perpendicular as well as oblique field-induced stripes relative to the initial orientation of the director are both examined with explicit indications of the time scales needed for their appearance and posterior development.

Immediate hip spica is as effective as, but more efficient than, flexible intramedullary nailing for femoral shaft fractures in pre-school children.

Flexible intramedullary nailing (FIN) is the gold standard treatment for femur fracture in school-aged children. It has been performed successfully in younger children, although Spica cast immobilisation (SCI) has been the most widely used strategy to date. METHOD: A retrospective analysis was performed between two comparable groups of children aged 1-4 years with a femoral shaft fracture. Two University hospitals, each using specific treatment guidelines, participated in the study: SCI in Group I (Basel, Switzerland) and FIN in Group II (Lausanne, Switzerland). RESULTS: Group I included 19 children with a median age of 26 months (range 12-46 months). Median hospital stay was 1 day (range 0-5 days) and casts were retained for a median duration of 21 days (range 12-29 days). General anaesthesia was used in six children and sedation in four. Skin breakdown secondary to cast irritation occurred in two children (10.5%). The median follow-up was 114 months (range 37-171 months). No significant malunion was noted. Group II included 27 children with a median age of 38.4 months (range 18.7-46.7 months). Median hospital stay was 4 days (range 1-13 days). All children required general anaesthesia for insertion and removal of the nails. Free mobilisation and full weight bearing were allowed at a median of 2 days (range 1-10 days) and 7 days (range 1-30 days), respectively, postoperatively. Nail exteriorisation was noted in three children (11%). The median follow-up was 16.5 months (range 8-172 months). No significant malunion was reported. CONCLUSIONS: Young children with a femoral shaft fracture treated by SCI or FIN had similarly favourable outcomes and complication rates. FIN allowed earlier mobilisation and full weight bearing. Compared to SCI, a greater number of children required general anaesthesia. In a pre-school child with a femoral shaft fracture, immediate SCI applied by a paediatric orthopaedic team following specific guidelines allowed early discharge from hospital with few complications.

Influence of bedrock structures on the spatial pattern of erosional landforms in small alpine catchments

Structural settings and lithological characteristics are traditionally assumed to influence the development of erosional landforms, such as gully networks and rock couloirs, in steep mountain rock basins. The structural control of erosion of two small alpine catchments of distinctive rock types is evaluated by comparing the correspondences between the orientations of their gullies and rock couloirs with (1) the sliding orientations of potential slope failures mechanisms, and (2) the orientation of the maximum joint frequency, this latter being considered as the direction exploited primarily by erosion and mass wasting processes. These characteristic orientations can be interpreted as structural weaknesses contributing to the initiation and propagation of erosion. The morphostructural analysis was performed using digital elevation models and field observations. The catchment comprised of magmatic intrusive rocks shows a clear structural control, mostly expressed through potential wedges failure. Such joint configurations have a particular geometry that encourages the development of gullies in hard rock, e.g. through enhanced gravitational and hydrological erosional processes. In the catchment underlain by sedimentary rocks, penetrative joints that act as structural weaknesses seem to be exploited by gullies and rock couloirs. However, the lithological setting and bedding configuration prominently control the development of erosional landforms, and influence not only the local pattern of geomorphic features, but the general morphology of the catchment. The orientations of the maximum joint frequency are clearly associated with the gully network, suggesting that its development is governed by anisotropy in rock strength. These two catchments are typical of bedrock-dominated basins prone to intense processes of debris supply. This study suggests a quantitative approach for describing the relationship between bedrock jointing and geomorphic features geometry. Incorporation of bedrock structure can be relevant when studying processes governing the transfer of clastic material, for the assessment of sediment yields and in landforms evolution models.

Cellular perspectives on the glutamate-monoamine interactions in limbic lobe structures and their relevance for some psychiatric disorders.

Dopaminergic, serotonergic and noradrenergic nuclei form the trimonoamine modulating system (TMMS). This system modulates emotional/motivational activities mediated by the limbic circuitry, where glutamate is the major excitatory neurotransmitter. Two main concepts are the basis of this review. First, since 1950 and the discovery of the antipsychotic activity of the dopamine D2 receptor antagonist chlorpromazine, it appears that drugs that can modulate the TMMS possess therapeutic psychiatric properties. Second, the concept of glutamate/trimonoamine imbalance in the cortico-striato-thalamo-cortical loop that has been so successful in explaining the pathophysiology of Parkinson disease has been applied in the pathophysiology of schizophrenia. This review will focus on the complex interactions between the fast synaptic glutamatergic transmission and the TMMS in specific parts of the limbic lobe and we will try to link these interactions to some psychiatric disorders, mainly depression, schizophrenia and drug addiction.

Catch-up growth strategies differ between body structures: interactions between age and structure-specific growth in wild nestling Alpine swifts

1. Little is known on the occurrence and magnitude of faster than normal (catch-up) growth in response to periods of undernutrition in the wild, and the extent to which different body structures compensate and over what timescales is poorly understood. 2. We investigated catch-up growth in nestling Alpine Swifts, Apus melba, by comparing nestling growth trajectories in response to a naturally occurring 1-week period of inclement weather and undernutrition with growth of nestlings reared in a good year. 3. In response to undernutrition, nestlings exhibited a hierarchy of tissues preservation and compensation, with body mass being restored quickly after the end of the period of undernutrition, acceleration of skeletal growth occurring later in development, and compensation in wing length occurring mostly due to a prolongation of growth and delayed fledging. 4. The effect of undernutrition and subsequent catch-up growth was age-dependent, with older nestlings being more resilient to undernutrition, and in turn having less need to compensate later in the development. 5. This shows that young in a free-living bird population can compensate in body mass and body size for a naturally occurring period of undernutrition, and that the timing and extent of compensation varies with age and between body structures.

Alternative Flexible Overlays, HR-229, 1988

The objective of this project was to determine if any of several cutback and emulsified asphalt plant mixed and road mixed overlays had the ability to resist thermal cracking at low temperatures without inducing shoving and/or ruttinq at high temperatures. A 2.6 mile section of Osceola County road A-34 and a 7.0 mile section of A-46 were divided into 14 test sections of various lengths. After six years, results show an MC-3000 asphalt cutback cold mix can reduce the amount of reflective cracking when compared to an AC-5 hot mix. This can be done without inducing high temperature related problems. Cold road mixing can be effective in reducing cracking on low volume roads. However, more experience is required if the full benefits of road mixing are to be realized.