The gastrin-releasing peptide receptor is differentially coupled to adenylate cyclase and phospholipase C in different tissues

A magnetization-prepared sequence, T2-Prep-IR, exploits T1, T2, and chemical shift differences to suppress background tissues relative to arterial blood. The resulting flow-independent angiograms depict vessels with any orientation and flow velocity. No extrinsic contrast agent is required. Muscle is the dominant source of background signal in normal volunteers. However, long-T2 deep venous blood and nonvascular fluids such as edema also contribute background signal in some patients. Three sets of imaging parameters are described to address patient-specific contrast requirements. A rapid, spiral-based, three-dimensional readout is utilized to generate high-resolution angiograms of the lower extremities. Comparisons with x-ray angiography and two-dimensional time-of-flight angiography indicate that this flow-independent technique has unique capabilities to accurately depict stenoses and to visualize slow flow and in-plane vessels.     

Pharmacology and intracellular signaling mechanisms of the native human orphan receptor BRS-3 in lung cancer cells

Neither the native ligand nor the cell biology of the bombesin (Bn)-related orphan receptor subtype 3 (BRS-3) is known. In this study, we used RT-PCR to identify two human lung cancer lines that contain sufficient numbers of native hBRS-3 to allow study: NCI-N417 and NCI-H720. In both cell lines, [DPhe6,betaAla11,Phe13, Nle14]Bn(6-14) stimulates [3H]inositol phosphate. In NCI-N417 cells, binding of 125I-[DTyr6,betaAla11,Phe13,Nle14]Bn(6-14) was saturable and high-affinity. [DPhe6,betaAla11,Phe13,Nle14]Bn(6-14) stimulated phospholipase D activity and a concentration-dependent release of [3H]inositol phosphate (EC50 = 25 nM) and intracellular calcium (EC50 = 14 nM); the increases in intracellular calcium were primarily from intracellular stores. hBRS-3 activation was not coupled to changes in adenylate cyclase activity, [3H]-thymidine incorporation or cell proliferation. No naturally occurring Bn-related peptides bound or activated the hBRS-3 with high affinity. Four different bombesin receptor antagonists inhibited increases in [3H]inositol phosphate. Using cytosensor microphysiometry, we found that [DPhe6,betaAla11,Phe13, Nle14]Bn(6-14) caused concentration-dependent acidification. The results show that native hBRS-3 receptors couple to phospholipases C and D but not to adenylate cyclase and that they stimulate mobilization of intracellular calcium and increase metabolism but not growth. The discovery of human cell lines with native, functional BRS-3 receptors, of new leads for a more hBRS-3-specific antagonist and of the validity of microphysiometry as an assay has yielded important tools that can be used for the identification of a native ligand for hBRS-3 and for the characterization of BRS-3-mediated biological responses.     

Value of anterior chamber lenses in developing countries. Results of a clinical study

There are estimated to be 20 million people blinded by cataracts, 80-90% of whom live in rural areas of developing countries where expert surgical resources are scarce. The majority of all cataract operations are still intracapsular extractions (ICCE). Aphakic correction using spectacles is problematical in developing countries. This study was undertaken to evaluate the safety of multiflex open loop anterior chamber intraocular lenses (AC IOLs). METHODS: A total of 2000 people attending Lahan Eye Hospital, South-east Nepal, with bilateral cataract were randomly allocated to receive in their first eye either ICCE with AC IOL (AC IOL group) or ICCE with aphakic correction (control group). All operations were performed by two ophthalmologists using a standardized technology and 4.5 x operating loupe magnification. Functional and best corrected vision was recorded. The primary outcome measure was poor vision after surgery, which was defined as a visual acuity of less than 6/60 at 1 year follow-up (WHO definition for severe visual impairment and blindness). FINDINGS: The median time needed to perform ICCE was 4.1 min and to perform ICCE with AC IOL 6 min. Of all study patients 91% were examined after 1 year. Five percent of the AC IOL group and 5.4% of the control group had a functional visual acuity of less than 6/60. Causes of reduced vision in the AC IOL group versus the control group were: correctable refractive error (22 vs 29), uveitis/secondary glaucoma (13 vs 2), endophthalmitis (4 vs 7), pre-existing eye diseases (4 vs 5), retinal detachment (0 vs 4), and corneal decompensation (0 vs 1). Of the control group, 24 patients were found to be functionally blind in the operated eye (vision < 3/60) because they did not wear their aphakic spectacles. Normal vision (WHO definition: > or = 6/18) was achieved best corrected in 89.9% of the AC IOL group and 93.2% of the control group. Analysis of additional long-term follow-ups (2-5 years post-operatively) has not yet been completed. INTERPRETATION: This study provides evidence that in developing countries well-manufactured multiflex open loop AC IOLs can be implanted safely by experienced ophthalmologists after routine ICCE, avoiding the disadvantages of aphakic spectacle correction.     

Minimizing makespan during environmental stress screening using a genetic algorithm and an ant colony optimization

The environmental stress screening (ESS) chamber employed in a typical electronics manufacturing service (EMS) provider’s facility is used for screening products, attempting to expose defects that cannot be detected by visual inspection or electrical testing. The ESS chambers are bottleneck work centers in most of the EMS facilities. This research uses a genetic algorithm (GA) and an ant colony optimization (ACO) to solve the job-scheduling problem at the ESS chamber where the makespan of the process is minimized. The performances of the two approaches were compared against some of the first-fit (FF) techniques from the literature. Both the GA and ACO techniques produced satisfactory results up to a job size of 40. Furthermore, ACO generally requires a longer computational time, while offering more consistent solution quality.     

Distributed source coding using syndromes (DISCUS): design and construction

We address the problem of compressing correlated distributed sources, i.e., correlated sources which are not co-located or which cannot cooperate to directly exploit their correlation. We consider the related problem of compressing a source which is correlated with another source that is available only at the decoder. This problem has been studied in the information theory literature under the name of the Slepian-Wolf (1973) source coding problem for the lossless coding case, and as "rate-distortion with side information" for the lossy coding case. We provide a constructive practical framework based on algebraic trellis codes dubbed as DIstributed Source Coding Using Syndromes (DISCUS), that can be applicable in a variety of settings. Simulation results are presented for source coding of independent and identically distributed (i.i.d.) Gaussian sources with side information available at the decoder in the form of a noisy version of the source to be coded. Our results reveal the promise of this approach: using trellis-based quantization and coset construction, the performance of the proposed approach is 2-5 dB from the Wyner-Ziv (1976) bound.     

Yield optimization in large RAM's with hierarchical redundancy

The authors present and analyze large RAM architectures with hierarchical redundancy and determine the optimal redundancy organization for yield enhancement. A two-level redundancy scheme is used for defect tolerance, and the defect distribution is modeled using the compounded Poisson model. The tree random access memory (TRAM), which has been proposed as a design methodology for future multimegabit memories (N. Jarwala et al., 1988) is considered as an example for modeling and optimization. The results show that the two-level hierarchical redundancy approach, with spare bit and word lines within memory quadrants, and additional spare modules for global sparing, along with redundant interconnections can efficiently provide defect tolerance and viable yields for future generations of high-density dynamic random access memories     

The hyper-deBruijn networks: scalable versatile architecture

Both Hypercube and deBruijn networks possess desirable properties. It should be understood, though, that some of the attractive features of one are not found in the other. The architecture proposed in this paper is a combination of these architectures, providing some of the desirable properties of both the networks such as admitting many computationally important networks, flexibility in terms of connections per node as well as level of fault-tolerance. Also the network allows a simple VLSI layout, scalability as well as decomposability. Thus, these networks can be a potential candidate for VLSI multiprocessor networks. The proposed network possesses logarithmic diameter, optimal connectivity, and simple routing algorithms amendable to networks with faults. Importantly, in addition to being pancyclic, these hyper-deBruijn networks admit most computationally important subnetworks including rings, multidimensional meshes, complete binary trees, and mesh of trees with perfect dilation. Techniques for optimal one-to-all (OTA) broadcasting in these networks are presented. As an intermediate result, this technique provides the fastest OTA broadcasting in binary deBruijn networks as well. The recent renewed interest in binary deBruijn networks makes this later result valuable     

A mathematical model for industrial projects location

The location of an industrial project is one of the major decisions an entrepreneur has to take. The classical approach in locational analysis is based on cost minimization (especially the aggregate transport cost). Later investigations have dealt with profit maximization. This paper presents the method of developing a comprehensive model for determining the optimum plant location for an industry—considering both the objective (quantitative) factors and the subjective (non-quantitative) factors. The approach followed here identifies all the objective factors and the subjective factors at the micro level and optimizes the overall benefit to the entrepreneur. A method has been devised to evaluate the intangible factors and to combine them with the tangible factors to obtain the overall locational measure. This is done by converting the factors into consistent and dimensionless indices for comprehensive evaluation. Thus the model presented here can be used as a tool to determine the optimum plant location for a new industrial project and also to establish priorities among the feasible plant locations.