A biochemical microdevice with an integrated chemiluminescence detector

By taking advantage of both the semiconductor properties and the advanced micromachining possibilities of silicon, integration of back-side photodiodes with a microfluidic channel network on a single substrate is accomplished. The resulting microsystem has all fluidic and electrical connections on one side of the chip. Hermetic sealing by anodic bonding is greatly facilitated by the simple topography on the front-side of the chip. To test the chemical functionality and performance of the device a chemiluminescence-based detection scheme is implemented. The introduction and control of the necessary chemical solutions is achieved using a flow injection analysis approach. Hydrogen peroxide is used as a model compound; injected plugs with concentrations in the range of 100 μM to 1 mM are successfully detected.     

100美元，将决定电子书兴衰两重天

作为国内较早接触电子书阅读器的一个用户．从索尼Pocket Edition PRS-300开始，我前后接触的专业电子书产品不下七款。曾经有不少身边的朋友对我随身携带的电子书表示了浓厚的兴趣．但在知道它们最少也要1700元人民币的时候．无一例外地打了退堂鼓。到现在，这些喜欢看书的朋友手中浏览电子书文件的利器基本上多是手机、PDA，NDS和PSP．却没有一个人愿意买下专业的电子书阅读器。深入人心的性价比观念，第一次让我哭笑不得。     

Vulnerability analysis of large concrete dams using the continuum strong discontinuity approach and neural networks

Probabilistic analysis is an emerging field of structural engineering which is very significant in structures of great importance like dams, nuclear reactors etc. In this work a Neural Networks (NN) based Monte Carlo Simulation (MCS) procedure is proposed for the vulnerability analysis of large concrete dams, in conjunction with a non-linear finite element analysis for the prediction of the bearing capacity of the Dam using the Continuum Strong Discontinuity Approach. The use of NN was motivated by the approximate concepts inherent in vulnerability analysis and the time consuming repeated analyses required for MCS. The Rprop algorithm is implemented for training the NN utilizing available information generated from selected non-linear analyses. The trained NN is then used in the context of a MCS procedure to compute the peak load of the structure due to different sets of basic random variables leading to close prediction of the probability of failure. This way it is made possible to obtain rigorous estimates of the probability of failure and the fragility curves for the Scalere (Italy) dam for various predefined damage levels and various flood scenarios. The uncertain properties (modeled as random variables) considered, for both test examples, are the Young’s modulus, the Poisson’s ratio, the tensile strength and the specific fracture energy of the concrete.     

A broad and narrow approach to interactive evolutionary design—An aircraft design example

While interactive evolutionary computation (IEC) is starting to penetrate a larger scientific community, only few researchers have applied IEC to the design of complicated artifacts like machines or transportation systems. The present paper introduces a specific approach to interactive evolutionary computation that breaches the two historical categories of user-defined fitness and selection in each generation (narrow) and occasional user-intervention of an automated evolutionary process to correct the fitness function used for (multi-objective) optimization (broad). To highlight the approach, a real world aircraft design problem is employed that demonstrates the relevance and importance of both features for an effective design process.     

The outcome of patients with upper airway obstruction transported to a regional paediatric intensive care unit

Two cases of nodular hidradenoma of the breast with possibly different origins are reported. Case 1 is of a 58-year-old female with a breast mass in the left, outer lower-quadrant. A histogenetical origin in the skin adnexal glands was suspected due to its superficial location and immunohistochemical findings. Case 2 is of a 44-year-old male with a subareolar nodule and nipple discharge. Histological examination demonstrated that the tumor was located deep in the breast tissue, was surrounded by dilated mammary ducts and exhibited intraductal extensions, which are all features mimicking those of breast cancer. Immunohistochemical positivity against gross cystic disease fluid protein-15 was weakly identified and negativity for endoplasmic reticulum was observed. This case can be interpreted as arising in the mammary ducts. It is well known that various kinds of skin adnexal tumors arise in the breast tissue; however, nodular hidradenoma of the breast is still a rare benign neoplasm. Clinically, nodular hidradenoma of the breast tends to occur in the nipple or subareolar region of the female breast. It should be kept in mind that nodular hidradenoma may occur in mammary ducts and it should be included when differential diagnoses are made of subareolar breast tumors.     

Proportional fair throughput allocation in multirate IEEE 802.11e wireless LANs

Under heterogeneous radio conditions, Wireless LAN stations may use different modulation schemes, leading to a heterogeneity of bit rates. In such a situation, 802.11 DCF allocates the same throughput to all stations independently of their transmitting bit rate; as a result, the channel is used by low bit rate stations most of the time, and efficiency is low. In this paper, we propose a more efficient throughput allocation criterion based on proportional fairness. We find out that, in a proportional fair allocation, the same share of channel time is given to high and low bit rate stations, and, as a result, high bit rate stations obtain more throughput. We propose two schemes of the upcoming 802.11e standard to achieve this allocation, and compare their delay and throughput performance. Albert Banchs received his M.Sc. and Ph.D. degrees in Telecommunications from the Technical University of Catalonia in 1997 and 2002, respectively. His Ph.D. received the national award for best thesis on Broadband Networks granted by the Professional Association of Telecommunication Engineers. He worked for the International Computer Science Institute, Berkeley, in 1997, for Telefonica I+D, Madrid, in 1998 and for NEC Network Laboratories, Heidelberg, from 1998 to 2003. Since 2003 he is with the University Carlos III of Madrid. Dr. Banchs is Associate Editor of IEEE Communications Letters and has been TPC member of several conferences and workshops including INFOCOM, ICC, GLOBECOM and QoS-IP. His current research interests include resource allocation, QoS and performance evaluation of wireless and wired networks. Pablo Serrano was born in Tarifa, Spain, on May 17, 1979. He received a M.Sc. degree in Telecommunications from the University Carlos III of Madrid in 2002. Since that date he is a Ph.D. candidate and a lecturer at the Telematics Department of the same university. His current research interests are performance evaluation and resource allocation of WLAN networks. Huw Edward Oliver received his MA degree in Mathematics at Cambridge University (1980), and his MSc (1985) and PhD (1988) in Computer Science at the University College of Wales, Aberystwyth. He joined Hewlett-Packard Laboratories, Bristol in 1989 to work on Software Development Environments. Following a period at HP’s Software Engineering Systems, Colorado in 1992 he returned to HP Labs in 1993 as Senior Member of Technical Staff and worked on real-time fault tolerant telecommunication systems. From 1997 to 2000 he was appointed Manager of Hewlett-Packard’s Internet Research Institute. He worked as Technical Director of the European MMAPPS Project from 2000 to 2002, as Senior Research Fellow at Lancaster University from 2002 to 2004, and as Visiting Professor at University Carlos III of Madrid from 2004 to 2005. Since 2005 he has been Senior Researcher with Ericsson R&D Ireland, Athlone where he is responsible for the next-generation network management architecture.