Stress distribution in thick-walled cylinder due to non-uniform radial pressure on the example of reinforcement corrosion in concrete

This paper presents an analytical solution to the non-uniform pressure on thick-walled cylinder. The formulation is based on the linear elasticity theory (plain strain) and stress function method. As an example, the proposed solution is used to model the stress distribution due to non-uniform steel reinforcement corrosion in concrete. The model is formulated considering different scenarios of corrosion pressure distribution. It is validated against the finite element model for different cases of non-uniform pressure distributions. The results show that the corrosion-induced cracks are likely to start just beyond the anodic zone. This is confirmed by the experimental tests on concrete cylinder exposed to non-uniform accelerated corrosion of steel reinforcement. The model can be effectively used to calculate the distribution of corrosion-induced stresses in concrete.     

Histologically confirmed changes on CT of reoperated low-grade astrocytomas

During a 15-year period 37 patients with primary low-grade astrocytoma have been operated upon twice in our institute. CT and histological data at the time of the first and second operations were compared. The majority of primary astrocytomas showed as a low-density area without contrast enhancement; minimal, mainly marginal enhancement was present in six cases. At reoperation 10 tumours were histologically unchanged; the corresponding CT studies displayed a nonenhancing lesion, although insignificant contrast uptake could be seen in three cases. There were 18 tumours which had transformed into anaplastic astrocytoma: CT before repeat surgery showed more or less marked enhancement. In all nine cases which progressed into glioblastoma multiforme strong contrast enhancement was seen on CT at the time of recurrence. Although the grade of contrast uptake varied, the appearance of or increase in enhancement was a sign of some degree of anaplastic change, particularly convincing in cases of dedifferentiated glioblastoma multiforme.     

The conformal alpha shape filtration

Conformal alpha shapes are a new filtration of the Delaunay triangulation of a finite set of points in ℝ^d. In contrast to (ordinary) alpha shapes the new filtration is parameterized by a local scale parameter instead of the global scale parameter in alpha shapes. The local scale parameter conforms to the local geometry and is motivated from applications and previous algorithms in surface reconstruction. We show how conformal alpha shapes can be used for surface reconstruction of non-uniformly sampled surfaces, which is not possible with alpha shapes.     

Reaching-to-eat in humans post-stroke: Fluctuating components within a constant pattern.

Reaching movements of the arm and hand become automatic early in development and are used throughout one's life span. Studies on skilled reaching have focused on the kinematic aspects and have advanced our knowledge of the individual motor components of reaching. It has also been shown that motor behaviors are organized in terms of ethologically relevant actions, rather than by motor components. Thus, it is important to analyze how the motor components of reaching are performed within the overall action as a whole. The objective of the present study was to examine the motor components of reaching-to-eat within the context of the overall behavior in stroke participants. Results show that reaching-to-eat involves the whole body to produce isolated actions of the limb and changes after stroke in three fundamental ways: abnormal use of nonkinematic aspects of movement, body-limb disintegration, and a disruption in the temporal aspect of the phases of reaching-to-eat. The movements within the behavior can reorganize, possibly a reflection of dynamic interactions between behavioral compensation and neuroplasticity, while the overall performance of the behavior remains the same. Such subtle flexibility may be part of the process of recovery. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fair content dissemination in participatory DTNs

Thanks to advances in the computing capabilities and added functionalities of modern mobile devices, creating and consuming digital media on the move has never been so easy and popular. Most of the DTN routing protocols proposed in the literature to enable content sharing have been exploiting users’ mobility patterns, in order to maximise the delivery probability, while minimising the overall network overhead (e.g., number of message replicas in the system, messages’ path length). Common to all these protocols has been the assumption that devices are willing to participate in the content distribution network; however, because of battery constraints, participation cannot be taken for granted, especially if the very same subset of devices are continuously selected as content carriers, simply because of their mobility properties. Indeed, we demonstrate that state-of-the-art DTN routing protocols distribute load in a highly unfair manner, with detrimental effects on delivery once the assumption of unconditional participation is lifted. To overcome this limitation, we propose a load-balancing mechanism whereby nodes maintain local estimates of network workload, and use them to direct traffic towards the least loaded portion of the network. We implement the mechanism on top of a source-based DTN routing protocol, and demonstrate, by means of simulation using a variety of real mobility traces, that high delivery is now achieved without compromising fairness.     

Adjuvant therapy with dibromodulcitol and BCNU increases survival of adults with malignant gliomas. EORTC Brain Tumor Group

OBJECTIVE: We tested adjuvant chemotherapy combining dibromodulcitol (DBD) and bischloroethylnitrosourea (BCNU) given postoperatively to adults with newly diagnosed supratentorial malignant gliomas. METHODS: We enrolled 269 patients, 255 of whom were eligible. After surgery, we treated all patients with radiation therapy, using a median dose of 60 Gy given in 30 fractions. After randomization, patients in the chemotherapy group also received (1) six weekly courses, administered during irradiation, of DBD 700 mg/m2 and (2) one to nine (median, four) courses, administered during the first year following radiation therapy, of DBD 1,000 mg/m2 on day 1 and BCNU 150 mg/m2 on day 2, with the course being repeated every 6 weeks. RESULTS: Patients treated with radiation therapy along with DBD plus BCNU (group 2) had significantly longer survival time (p = 0.044) and time to progression (p = 0.003) than did those treated with radiation therapy alone (group 1). The median survival time was 13.0 months for group 2 and 10.4 months for group 1; the median time to progression was 8.1 months for group 2 and 6.7 months for group 1. The percentage of patients alive at 18 and 24 months was 34% and 21% in group 2 compared with 21% and 12% in group 1. CONCLUSION: DBD plus BCNU is an effective adjuvant therapy for malignant glioma.     

Building a Usable and Accessible Semantic Web Interaction Platform

Semantic Web applications take off is being slower than expected, at least with respect to “real-world” applications and users. One of the main reasons for this lack of adoption is that most Semantic Web user interfaces are still immature from the usability and accessibility points of view. This is due to the novelty of these technologies, but this also motivates the exploration of alternative interaction paradigms, different from the “traditional” Web or Desktop applications ones. Our proposal is realized in the Rhizomer platform, which explores the possibilities of the object–action interaction paradigm at the Web scale. This paradigm is well suited for heterogeneous resource spaces such as those common in the Semantic Web. Resources, described by metadata, correspond to the objects in the paradigm. Semantic web services, which are dynamically associated to these objects, correspond to the actions. The platform is being put into practice in the context of a research project in order to build an open application for media distribution based on Semantic Web technologies. Moreover, its usability and accessibility have been evaluated in this real setting and compared to similar systems.