Multicentric primary adenocarcinomas of the midgut: the first case report

Multicentric adenocarcinomas of the midgut have not been described; even multiple adenocarcinomas limited to the small intestine are extremely uncommon, with only 14 cases reported in the literature. We report a case of multicentric synchronous involvement of the entire midgut with adenocarcinoma in a 52-yr-old Polish woman who had more than 30 lesions extending from duodenum to mid-transverse colon. There was no family history of cancer. Preoperative evaluation and intraoperative exploration were negative for primary malignancy of the lungs, breasts, ovaries, pancreas, and other parts of the gastrointestinal tract. Results of histopathological examination, immunohistochemical staining, and ras mutational analysis of the lesions uniformly support the diagnosis of multicentric poorly differentiated adenocarcinoma. The cause for this unusual presentation is unknown, although sporadic genetic alteration(s) of oncogene(s) might have been the precipitating event.     

Differential requirement for p56lck in fetal and adult thymopoiesis

The protein tyrosine kinase p56lck is critical for the generation of mature thymocytes in adult mice. However its requirement during the maturation of thymocytes from the fetal to the adult stage has not been clearly defined. We analyzed prenatal and postnatal thymocyte maturation in mice deficient for p56lck (lck[-/-]). Before birth, lck appears to play a crucial role in the expansion and proliferation of CD4+CD8+ double positive thymocytes, whereas proliferation and absolute numbers of CD4-CD8- double negative thymocyte precursors remained within the normal range until the end of the second week postnatal. Three weeks after birth, the total numbers of double negative and immature single positive thymocytes underwent a dramatic reduction that correlated with a decrease in the double positive population. This ontogenic defect was associated with a significant decrease in the proliferation rates of thymocyte precursors. Our data suggest that signaling via p56lck kinase is differentially required within a given phenotypically defined thymocyte subpopulation, depending on its stage of thymocyte maturation.     

On the Design of a Programmable-Gain Amplifier With Built-In Compact DC-Offset Cancellers for Very Low-Voltage WLAN Systems

Two circuit techniques adopted in the design of an embedded programmable-gain amplifier (PGA) for very low-voltage (LV) wireless local-area network systems are presented. A switched-current-resistor (SCR) technique minimizes the bandwidth variation and the transient in gain tuning by stabilizing, concurrently, the PGA's feedback factor and quiescent-operating point. Another technique, inside-opamp dc-offset canceller (DOC), embeds inside the PGA's opamp a subthreshold-biased - integrator for extracting its output dc-offset, while negatively feeding the correction (current) signal back to the opamp at an inherent low-impedance node. The resultant main benefits are: 1) the chip area, for realizing the large time constant in dc-offset extraction, is very small and 2) the lower cutoff of the PGA and the DOC-induced nonlinearity and noise are all suppressed by an amount of the loop gain in closed-loop formation. A 1-V three-stage 52-dB gain range PGA reinforcing such two techniques was designed and fabricated in a 3.3-V 0.35- CMOS process. It consumes 7.4 mW of power while measuring gain-switching transient and IIP3. The means of the lower and upper cutoffs (averaged over 52-dB gain steps) are 2.25 kHz and 17.1 MHz, respectively.     

Kernel Eigenspace-Based MLLR Adaptation

In this paper, we propose an application of kernel methods for fast speaker adaptation based on kernelizing the eigenspace-based maximum-likelihood linear regression adaptation method. We call our new method "kernel eigenspace-based maximum-likelihood linear regression adaptation" (KEMLLR). In KEMLLR, speaker-dependent (SD) models are estimated from a common speaker-independent (SI) model using MLLR adaptation, and the MLLR transformation matrices are mapped to a kernel-induced high-dimensional feature space, wherein kernel principal component analysis is used to derive a set of eigenmatrices. In addition, a composite kernel is used to preserve row information in the transformation matrices. A new speaker's MLLR transformation matrix is then represented as a linear combination of the leading kernel eigenmatrices, which, though exists only in the feature space, still allows the speaker's mean vectors to be found explicitly. As a result, at the end of KEMLLR adaptation, a regular hidden Markov model (HMM) is obtained for the new speaker and subsequent speech recognition is as fast as normal HMM decoding. KEMLLR adaptation was tested and compared with other adaptation methods on the Resource Management and Wall Street Journal tasks using 5 or 10 s of adaptation speech. In both cases, KEMLLR adaptation gives the greatest improvement over the SI model with 11%-20% word error rate reduction     

Super-resolution reconstruction in a computational compound-eye imaging system

From consumer electronics to biomedical applications, device miniaturization has shown to be highly desirable. This often includes reducing the size of some optical systems. However, diffraction effects impose a constraint on image quality when we simply scale down the imaging parameters. Over the past few years, compound-eye imaging system has emerged as a promising architecture in the development of compact visual systems. Because multiple low-resolution (LR) sub-images are captured, post-processing algorithms for the reconstruction of a high-resolution (HR) final image from the LR images play a critical role in affecting the image quality. In this paper, we describe and investigate the performance of a compound-eye system recently reported in the literature. We discuss both the physical construction and the mathematical model of the imaging components, followed by an application of our super-resolution algorithm in reconstructing the image. We then explore several variations of the imaging system, such as the incorporation of a phase mask in extending the depth of field, which are not possible with a traditional camera. Simulations with a versatile virtual camera system that we have built verify the feasibility of these additions, and we also report the tolerance of the compound-eye system to variations in physical parameters, such as optical aberrations, that are inevitable in actual systems.     

New Dyes and Intermediates for Synthetic-polymer Fibres. 7,7-Dioxo-Benzo(K, /)thioxan-thene-3,4-dicarboxylic Acid Imides

The synthesis of benzo [k, l] thioxanthene-3,4-dicarbo-xylic acid-7,7-dioxide is described. Condensation of this heterocycle with amines, or oxidation of the corresponding imides of benzo [k, l] thioxanthene-3,4-dicarboxylic acid, affords a new range of dyes which colour synthetic-polymer fibres, especially polyester, in yellow shades of excellent fastness to light and sublimation.     

Effects of velocity slip on the elastohydrodynamic lubrication of short, porous journal bearings

The studies of Beavers and Joseph indicated that velocity slip takes place at the permeable boundary of porous bearings. The purpose of this article is to make an analytical study of a short, porous journal bearing taking into account both the effects of velocity slip at the film-bearing interface and the flexibility of the bearing. An analytical solution for the performance of such bearings is obtained in terms of several parameters involving porosity, slip coefficient, bearing dimensions and speed.     

The impact of alternative regional development strategies on crime rates: Tourism vs. agriculture in Hawaii

In recent years, Hawaii's exports have been dominated by tourism. Expansion of resort development, however, has frequently displaced agricultural land uses. This paper examines the hypothesis that an alteration in the composition of economic activity in the form of a displacement of agriculture by resort development will increase crime with a cross-section analysis of the determinants of crime rates for the island of Oahu in 1975 and a parallel time series analysis for Hawaii over the period 1961–1975. Empirical estimates indicate that a significantly greater amount of burglaries, rapes, and larcenies will occur. Policy implications are then explored.We gratefully acknowledge the helpful comments of B. Campbell, M. Ghali, and W. Miklius. Our research assistants, E. Nishimura and B. Bocalbos performed the computations.     

Pentagastrin stimulates epithelial cell proliferation in duodenal and colonic crypts in fasted rats

In fasted rats, single injection of pentagastrin (250 mug/kg) stimulates epithelial cell proliferation in the duodenum and colon, but not in the esophagus. Fasting for 64 hours suppresses cell proliferation more markedly in colonic crypts than in duodenal crypts, and pentagastrin restores the cell proliferative activity of the colon and duodenum to levels comparable with those of fed rats. In both duodenal and colonic crypts, differentiating-proliferative cells in the mid-portion of the crypts are more responsive to pentagastrin stimulation than immature proliferative cells at the base of the crypts. Non-dividing epithelial cells are not affected. Pentagastrin has no influence on cell proliferation in fed rats.