Ultra wideband: the radio link of the future?

A new data transmission technique is about to create a revolution in the field of wireless local area networks. This new method, called Ultra Wideband, is based on the transmission of data through the communication channel below the noise floor. It involves transmitting very short duration pulses, which has the effect of spreading the signal energy across a wide frequency range. The objective of this article is to report on the state of the art in this research area, and to outline the main advantages of this promising data transmission method.     

Optimal operation of batch reactors—a personal view

This paper presents a personal, thus necessarily subjective, view of the operation of batch and semi-batch reactors. The emphasis is on safety, product quality and scale-up. Key characteristics of discontinuous reaction systems are discussed, along with the resulting implications for monitoring, control and optimization. The industrial needs are compared with the research solutions proposed by academia. It is argued that, in industry, measurement and modeling issues are often more important than the algorithmic aspects related to the computation of control and optimization strategies. Major challenges and selected research opportunities are discussed.     

Clinical and therapeutic aspects of spontaneous pneumothorax in human immunodeficiency virus infection: 9 cases

Spontaneous pneumothorax in HIV infected patients are mostly due to a sub-pleural necrotizing pneumonitis most often related to Pneumocystis carinii pneumonia. From our experience of nine patients and a review of the literature, we describe the clinical characteristics and therapeutic management and confirm the frequent failure of simple chest tube drainage and the high morbidity and mortality rate despite treatment. An aggressive stepped-care management of thoracoscopic talc poudrage as initial therapy should be evaluated.     

Speckle filtering in SAR images by contrast modification,comparison with a large class of filters

Speckle appearing in synthetic aperture radar (sar) images is generated by coherent processing of radar signals. Basically the speckle has the nature of multiplicative noise. Recently, several methods have been proposed to remove speckle in sar images, among them, Lee’s methods, Frost’s method and Zamperoni’s method. In this paper, we propose an effective method for smoothing speckle-corrupted images. Digital processing is introduced, based on a contrast modification in a multi-resolution pyramid image representation. The contrast modification is realized by a median filter or an adaptive order filter giving a reconstructed image. For assessing this new method, we realized a comparative study with several noise-smoothing algorithms.     

Diffusion-Weighted MRI and Response to Anti-Cancer Therapies

In oncology practice, longitudinal studies are routinely conducted to monitor the size and enhancement of tumors in cancer patients undergoing therapy. Imaging protocols typically use gadolinium-enhanced T₁-weighted images or T₂-weighted images from which tumor size is inferred and tumor response estimated. The past few years have also seen the emergence of diffusion-weighted magnetic resonance imaging (DWMRI) as a potential alternative to monitor therapeutic response (Kauppinen, R.A., NMR Biomed. 2002, 15, 6). The attractiveness of DWMRI resides in its ability to detect local microstructural changes associated with treatment long before their effects are translated into effective size changes. Damage to cell membrane integrity, changes in viscosity, and/or relative size of intra- vs. extracellular compartments all translate into changes in the apparent diffusion coefficient of tumor water measured by DWMRI. This dependence makes DWMRI a particularly sensitive method to detect response to a wide variety of chemotherapeutic agents. This review will focus on the emerging role of DWMRI to monitor the response of tumors to anti-cancer chemotherapies.     

A method for automatic design error location and correction in combinational logic circuits

We present a new diagnostic algorithm, based on backward-propagation, for localising design errors in combinational logic circuits. Three hypotheses are considered, that cover all single gate replacement and insertion errors. Diagnosis-oriented test patterns are generated in order to rapidly reduce the suspected area where the error lies. The originality of our method is the use of patterns which do not detect the error, in addition to detecting patterns. A theorem shows that, in favourable cases, only two patterns suffice to get a correction. We have implemented the test generation and diagnosis algorithms. Results obtained on benchmarks show that the error is always found, after the application of a small number of test patterns, with an execution time proportional to the circuit size. This work is partially supported by EUREKA “JESSI-AC3” project and the ESPRIT Basic Research Action CHARME Working Group #6018.     

1‐(1H‐Indol‐3‐yl)ethanamine Derivatives as Potent Staphylococcus aureus NorA Efflux Pump Inhibitors

The synthesis of 37 1‐(1H‐indol‐3‐yl)ethanamine derivatives, including 12 new compounds, was achieved through a series of simple and efficient chemical modifications. These indole derivatives displayed modest or no intrinsic anti‐staphylococcal activity. By contrast, several of the compounds restored, in a concentration‐dependent manner, the antibacterial activity of ciprofloxacin against Staphylococcus aureus strains that were resistant to fluoroquinolones due to overexpression of the NorA efflux pump. Structure–activity relationships studies revealed that the indolic aldonitrones halogenated at position 5 of the indole core were the most efficient inhibitors of the S. aureus NorA efflux pump. Among the compounds, (Z)‐N‐benzylidene‐2‐(tert‐butoxycarbonylamino)‐1‐(5‐iodo‐1H‐indol‐3‐yl)ethanamine oxide led to a fourfold decrease of the ciprofloxacin minimum inhibitory concentration against the SA‐1199B strain when used at a concentration of 0.5 mg L ^?1. To the best of our knowledge, this activity is the highest reported to date for an indolic NorA inhibitor. In addition, a new antibacterial compound, tert‐butyl (2‐(3‐hydroxyureido)‐2‐(1H‐indol‐3‐yl)ethyl)carbamate, which is not toxic for human cells, was also found.     

Place Attachment Among Older Adults Living in Four Communities in Flanders,Belgium

There is strong evidence that age brings an increasing attachment to social and physical environments. However, the extent to which the experience of place attachment may vary between different types of locations remains underexplored in ageing research. Using a mixed-method approach consisting of two consecutive phases, this article aims to identify contextual factors that either promote or impede older people's attachment to place. In the first phase, quantitative data from the Belgian Ageing Studies were used to purposively select four municipalities: two with relatively strong and two with relatively weak place attachments among the older population. In the second, qualitative phase, two focus groups with local stakeholders and 20 semi-structured interviews with older residents were conducted in each of the four case study areas in order to explain and build on the quantitative results. The qualitative findings focus on two contextual factors that have been linked to place attachment: the physical–spatial environment and population turnover. The study identifies the various pathways between these factors and older people's attachments. The article concludes by discussing practical and policy issues raised by the research.