Grouted and concreted soils: residue mapping of foundation techniques in Flanders,Belgium

Sand is one of the main raw materials used in infrastructure and road construction. While it is a common natural raw material worldwide, the locations where it can be found are not evenly distributed. Because Flanders is highly dependent on imported sand, there is a need to find alternatives. One alternative might be found in the residues from foundation techniques like grout, soil mixed with bentonite, and cemented soils. This paper reports an attempt to determine the annual amount of residues from these foundation techniques available on the Flemish market, by use of a market study. This study estimated that the annual amount of grouted soils and cemented soil remainders is more than 40% of the annual amount of natural sands dredged from the Belgian Continental Shelf. Preliminary tests show that grout and cemented soil remainders could be a valuable replacement for natural sand currently used in low grade applications like sub foundations and stabilized sands.     

Overexpression of the 67-kD laminin receptor correlates with tumour progression in human colorectal carcinoma

The high affinity 67-kD laminin receptor (67LR) is a cell surface protein whose expression is increased in a number of human carcinoma models. To date, 67LR expression in colorectal carcinomas has been examined in a small number of cases. 67LR expression has been immunohistochemically analysed in a large series of human colorectal neoplasms, using the MLuC5 monoclonal antibody. The study included 59 samples of non-neoplastic mucosa, 45 polyps (11 hyperplastic, 34 adenomas), 196 carcinomas, and lymph node metastases of 87 carcinomas. Epithelial cells of normal mucosa and hyperplastic polyps were negative or showed weak positivity in the paranuclear and apical areas of the cytoplasm. In adenomas and carcinomas, the staining was stronger, with a membranous or cytoplasmic pattern. The expression of 67LR correlated significantly with the progression from normal mucosa (22 per cent) to adenoma (44 per cent), carcinoma (61 per cent), and lymph node metastasis (75 per cent) (P < 0.0001). Expression of the laminin receptor showed a tendency to be more frequently positive in advanced stage (III+IV; 67 (III+IV; 67 per cent) when compared with early stage (I+II) carcinomas (54 per cent). The difference, however, was not statistically significant (P = 0.058). In addition, 14 out of 28 (50 per cent) primary carcinomas without 67LR expression became positive in lymph node metastases, while most (86 per cent) of the MLuC5-positive primary carcinomas were also immunoreactive in metastases. In conclusion, these results indicate that 67LR is up-regulated in the progression of human colorectal carcinomas and may play a role in the local and metastatic progression of these tumours.     

Warming and eutrophication effects on the phytoplankton communities of two tropical water systems of different trophic states: An experimental approach

Both global warming and eutrophication are predicted to promote cyanobacterial blooms. At the same time, how tropical phytoplankton communities exhibiting different trophic state systems will respond to temperature variations is less clear. To investigate the effects of temperature changes and nutrient additions on phytoplankton communities, and gain insights regarding possible resistance to these effects, the present study focused on testing the hypothesis that temperature variations and nutrient additions will have a stronger effect on cyanobacteria dominance in eutrophic water system than in oligo‐mesotrophic water systems. Experiments were conducted with phytoplankton communities from two aquatic ecosystems exhibiting different trophic states. To this end, water samples from a eutrophic and oligo‐mesotrophic system were collected and incubated at 25 and 30ºC. Samples receiving additional surplus nitrogen (N) and phosphorus (P) inputs were included to serve as eutrophication treatments. The study results indicated that temperature variations alone did not promote cyanobacteria in water from either the oligo‐mesotrophic or eutrophic water system. However, nutrient enrichment of the water from the eutrophic system significantly boosted the cyanobacteria, with the biomass increasing by factor of 10 for both the 25°C and 30°C treatments. In contrast, eutrophication of the water from the oligo‐mesotrophic system did not change the relative contribution of phytoplankton groups, with the response ratios being much lower than those for the water from the eutrophic system. Although based on a simple experimental design, the results of the present study suggest that cyanobacteria dominance is favoured by further nutrient additions for eutrophic water systems, independently of any direct temperature effects, and that more pristine environments possess some resistance against eutrophication effects. Since global warming is assumed to indirectly intensify eutrophication symptoms, the results of the present study underscore the importance of nutrient control.     

A polynomial alternative to unbounded environment for tissue P systems with cell division

The standard definition of tissue P systems includes a special alphabet whose elements are assumed to appear in the initial configuration of the system in an arbitrarily large number of copies. These objects reside in a distinguished place of the system, called the environment. Such potentially infinite supply of objects seems an unfair tool when designing efficient solutions to computationally hard problems in the framework of membrane computing, by performing a space–time trade-off. This paper deals with computational aspects of tissue P systems with cell division where there is no environment having the property mentioned above. Specifically, we prove that the polynomial complexity classes associated with tissue P systems with cell division and with or without environment are actually identical. As a consequence, we conclude that it is not necessary to have infinitely many copies of some objects in the initial configuration in order to solve NP–complete problems in an efficient way.     

Performance analysis of the Sent-But-Sure strategy for Optical Burst and Packet Switched Networks

This work proposes an analytical model to characterize the performance of a loss-free transmission strategy for Optical Burst and Packet Switched Networks, which ensures that a burst/packet will successfully reach its destination once it has been scheduled in the first link of its path. In this paper this strategy is called Sent-But-Sure (SBS) because it avoids losses in any intermediate node. The SBS strategy combines a routing and wavelength assignment scheme with simple contention resolution mechanisms. As a result, new burst/packet allocation attempts in an intermediate node only contend with bursts/packets in transit coming from a single input link. Moreover, bursts/packets in transit always have priority over bursts/packets whose transmission has not been scheduled yet. These two main features of the SBS strategy allow us to develop an analytical model based on a two-priority M/G/1 queueing model to characterize the network performance.     

Content annotation for the semantic web: an automatic web-based approach

Semantic Annotation is required to add machine-readable content to natural language text. A global initiative such as the Semantic Web directly depends on the annotation of massive amounts of textual Web resources. However, considering the amount of those resources, a manual semantic annotation of their contents is neither feasible nor scalable. In this paper we introduce a methodology to partially annotate textual content of Web resources in an automatic and unsupervised way. It uses several well-established learning techniques and heuristics to discover relevant entities in text and to associate them to classes of an input ontology by means of linguistic patterns. It also relies on the Web information distribution to assess the degree of semantic co-relation between entities and classes of the input domain ontology. Special efforts have been put in minimizing the amount of Web accesses required to evaluate entities in order to ensure the scalability of the approach. A manual evaluation has been carried out to test the methodology for several domains showing promising results.     

Formal communication elimination and sequentialization equivalence proofs for distributed system models

Equivalence reasoning with distributed system models, expressed directly as imperative programs with explicit parallelism, communication operations, storage variables and boolean conditions, remains virtually unexplored. Only reasoning with models expressed as process algebras has been amply dealt with in literature. However, these formalisms do not contemplate either storage variables or Boolean conditions as fundamental items, although these items become essential in most situations. This article develops the foundation of the until now non existent theory of equivalence reasoning with the aforementioned imperative notation and two novel equivalence proof techniques: communication elimination and sequentialization. The development is grounded on state systems and transition interleavings, as treated by Manna and Pnueli. Equivalence proofs safely transform a model via the application of a sequence of equivalence laws; aiming to obtain an equivalent model which is purely sequential, free from internal communication operations and parallelism, as a simplification of the initial model. After this, verification of the original model can be carried out, indirectly, in the simplified model, thus reducing complexity. Some of the presented novel notions are: (1) modular procedure for decomposition of both models and proofs, (2) interface behavior for statement semantics, (3) interface equivalence between behaviors, between statements and between procedures, (4) a set of communication elimination laws and (5) substitution rules of procedure references by their bodies or by references to equivalent procedures. An elimination proof construction algorithm is also presented; when it terminates, deadlock freedom of the original model can be decided. The main design lines of a computer aided equivalence reasoning tool are outlined as well. This is the foundation for a more widely applicable tool. As an illustration, the sequentialization proof of a simplified pipelined processor is overviewed. It is modeled as a distributed system with procedures and two levels of parallelism. The model obtained at the end of the equivalence proof is the sequential loop of a Von Neumann processor. This result establishes that the original model is deadlock-free, behaves as a processor and, as a consequence, the partition of processor functions among parallel processes is correct. The ratio of the upper bounds on the number of states of the final over the initial models, \(\frac{final}{initial}\) , is \(\frac{1}{2^{672}}\) .