9,517 research outputs found

    Cochlear Implant Outcomes and Genetic Mutations in Children with Ear and Brain Anomalies

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    Background. Specific clinical conditions could compromise cochlear implantation outcomes and drastically reduce the chance of an acceptable development of perceptual and linguistic capabilities. These conditions should certainly include the presence of inner ear malformations or brain abnormalities. The aims of this work were to study the diagnostic value of high resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in children with sensorineural hearing loss who were candidates for cochlear implants and to analyse the anatomic abnormalities of the ear and brain in patients who underwent cochlear implantation. We also analysed the effects of ear malformations and brain anomalies on the CI outcomes, speculating on their potential role in the management of language developmental disorders. Methods. The present study is a retrospective observational review of cochlear implant outcomes among hearing-impaired children who presented ear and/or brain anomalies at neuroimaging investigations with MRI and HRCT. Furthermore, genetic results from molecular genetic investigations (GJB2/GJB6 and, additionally, in selected cases, SLC26A4 or mitochondrial-DNA mutations) on this study group were herein described. Longitudinal and cross-sectional analysis was conducted using statistical tests. Results. Between January 1, 1996 and April 1, 2012, at the ENT-Audiology Department of the University Hospital of Ferrara, 620 cochlear implantations were performed. There were 426 implanted children at the time of the present study (who were <18 years). Among these, 143 patients (64 females and 79 males) presented ear and/or brain anomalies/lesions/malformations at neuroimaging investigations with MRI and HRCT. The age of the main study group (143 implanted children) ranged from 9 months and 16 years (average = 4.4; median = 3.0). Conclusions. Good outcomes with cochlear implants are possible in patients who present with inner ear or brain abnormalities, even if central nervous system anomalies represent a negative prognostic factor that is made worse by the concomitant presence of cochlear malformations. Common cavity and stenosis of the internal auditory canal (less than 2 mm) are negative prognostic factors even if brain lesions are absent

    Histomorphological and functional contralateral symmetry in the gastrocnemius muscles of the laboratory rat

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    It is usual in anatomical and physiological research to assess the effects of some intervention on extremities (e.g., training programmes or injury recovery protocols) using one muscle for the intervention and its contralateral as control. However, the existence of laterality (left-handedness or right-handedness) in athletes of different specialties is widely recognized. In rats, gastrocnemius is one of the muscles most widely used because of its importance in locomotion and high relative limb mass. Since we have not found studies reporting laterality assessment on the morphology and function in rat gastrocnemius, our study aimed to evaluate the fibre histochemical, morphometrical and muscle force contractile properties between right and left gastrocnemius of the laboratory rat. Fibre type proportion, fibre morphometrical measurements, muscle capillarization and muscle force properties were analysed in the right and left gastrocnemius of six male rats. No statistically significant differences (p=0.265) were found in gastrocnemius to body weight ratio (¿) between right (6.55±0.40) and left (6.49±0.40) muscles. The muscles analysed showed a great degree of heterogeneity in fibre type distribution, having three clearly distinguished regions named red, mixed and white. In the three regions, there were no statistical differences in fibre type proportions between right and left gastrocnemius, as is indicated by the p-values (from 0.203 to 0.941) obtained after running t-Student paired tests for each fibre type. When analysing fibre cross-sectional area, individual fibre capillarization and fibre circularity, no significant differences between right and left gastrocnemius in any of these morphometrical parameters were found in any muscle region or fibre type. Most of the p-values (70%) resulting from running t-Student paired tests were higher than 0.400, and the lowest p-value was 0.115. Seemingly, global capillary and fibre densities were not statistically different between right and left sides in all muscle regions with p-values ranging from 0.337 to 0.812. Force parameters normalized to gastrocnemius mass (mN·g-1) did not show any significant difference between right (PF=74.0±13.4, TF=219.4±13.0) and left (PF=70.9±10.7, TF=213.0±18.0) muscles with p=0.623 (PF) and p=0.514 (TF). Twitch time parameters (ms) also lacked significant differences between the two sides (CT: 43.4±8.6 vs 45.0±14.3, P=0.639; HRT: 77.6±15.0 vs 82.3±25.3, p=0.475). Finally, both muscles also showed similar (p=0.718) fatigue properties. We did find an absence of laterality at the morphological and functional levels, which raises the possibility of using right and left gastrocnemius muscles interchangeably for experimental designs where one muscle is used to analyse data after a physiological intervention and its contralateral muscle plays the control role, thus allowing unbiased paired comparisons to derive accurate conclusions

    Impact of daylighting on total energy use in offices of varying architectural features in Italy: Results from a parametric study

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    The growing attention towards the optimization of the overall performance of a building, in terms of both indoor environmental quality and energy consumption, has brought about the need to carry out analyses, which consider the interactions of all affecting parameters. In particular, thermal and daylighting analysis should be carried out in synergy to ensure the best performance in both domains. Within this framework, the paper presents a study on daylighting and energy behavior of rooms with different architectural features. The study has been conceived to account for a broad range of possible configurations of office buildings in the climate site of Turin (Northern Italy), and has been performed through numerical simulations carried out with Daysim and EnergyPlus. The results outline the daylighting performance (in terms of spatial Daylight Autonomy (sDA)) and the energy demand for lighting, heating and cooling and demonstrate that optimizing daylighting can lead to a reduction of the total energy demand of an office

    Upward Book Embeddings of st-Graphs

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    We study k-page upward book embeddings (kUBEs) of st-graphs, that is, book embeddings of single-source single-sink directed acyclic graphs on k pages with the additional requirement that the vertices of the graph appear in a topological ordering along the spine of the book. We show that testing whether a graph admits a kUBE is NP-complete for k >= 3. A hardness result for this problem was previously known only for k = 6 [Heath and Pemmaraju, 1999]. Motivated by this negative result, we focus our attention on k=2. On the algorithmic side, we present polynomial-time algorithms for testing the existence of 2UBEs of planar st-graphs with branchwidth b and of plane st-graphs whose faces have a special structure. These algorithms run in O(f(b)* n+n^3) time and O(n) time, respectively, where f is a singly-exponential function on b. Moreover, on the combinatorial side, we present two notable families of plane st-graphs that always admit an embedding-preserving 2UBE

    Unilateral climate policy and competitiveness: The implications of differential emission pricing

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    Unilateral emission reduction commitments raise concerns on international competitiveness and emission leakage that result in preferential regulatory treatment of domestic energy-intensive and trade-exposed industries. Our analysis illustrates the potential pitfalls of climate policy design which narrowly focuses on competitiveness concerns about energy-intensive and trade-exposed (EITE) branches. The sector-specific gains of preferential regulation in favour of these branches must be traded off against the additional burden imposed on other industries. Beyond burden shifting between industries, differential emission pricing bears the risk for substantial excess cost in emission reduction as policy concedes (too) low carbon prices to EITE industries and thereby foregoes relatively cheap abatement options in these sectors. From the perspective of global cost-effectiveness we find that differential emission pricing of EITE industries hardly reduces emission leakage since the latter is driven through robust international energy market responses to emission constraints. As a consequence the scope for efficiency compared to uniform pricing is very limited. Only towards stringent emission reduction targets will a moderate price differentiation achieve sufficient gains from leakage reduction to offset the losses of diverging marginal abatement cost.unilateral climate policy design, leakage, competitiveness

    Object integration requires attention: visual search for Kanizsa figures in parietal extinction

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    The contribution of selective attention to object integration is a topic of debate: integration of parts into coherent wholes, such as in Kanizsa figures, is thought to arise either from pre-attentive, automatic coding processes or from higher-order processes involving selective attention. Previous studies have attempted to examine the role of selective attention in object integration either by employing visual search paradigms or by studying patients with unilateral deficits in selective attention. Here, we combined these two approaches to investigate object integration in visual search in a group of five patients with left-sided parietal extinction. Our search paradigm was designed to assess the effect of left- and right-grouped nontargets on detecting a Kanizsa target square. The results revealed comparable reaction time (RT) performance in patients and controls when they were presented with displays consisting of a single to-be-grouped item that had to be classified as target vs. nontarget. However, when display size increased to two items, patients showed an extinction-specific pattern of enhanced RT costs for nontargets that induced a partial shape grouping on the right, i.e., in the attended hemifield (relative to the ungrouped baseline). Together, these findings demonstrate a competitive advantage for right-grouped objects, which in turn indicates that in parietal extinction, attentional competition between objects particularly limits integration processes in the contralesional, i.e., left hemifield. These findings imply a crucial contribution of selective attentional resources to visual object integration
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