Marc S. Weinberg

Bio: Marc S. Weinberg is an academic researcher from University of the Witwatersrand. The author has contributed to research in topics: RNA interference & Gene silencing. The author has an hindex of 46, co-authored 175 publications receiving 6480 citations. Previous affiliations of Marc S. Weinberg include College of Charleston & Scripps Research Institute.

A micromachined comb-drive tuning fork rate gyroscope

Abstract: The development of single-crystal and polysilicon tuning fork gyroscopes of very small size and low cost using microfabrication technology is reported. These tuning fork gyroscopes are extremely rugged, inherently balanced, and easy to fabricate. For a 1-mm gyroscope, projected performance is 10 to 100 degrees /hr for bias stability and for resolution in a 60-Hz bandwidth. To date, 5000 degrees /hr in a 60 Hz bandwidth has been demonstrated. The principle of operation, projected and measured performance and fabrication of silicon, polysilicon, and nickel units and associated electronics and control issues are discussed. >

The antisense strand of small interfering RNAs directs histone methylation and transcriptional gene silencing in human cells.

Abstract: To determine mechanistically how siRNAs mediate transcriptional gene silencing (TGS) in human cells, we have measured histone methylation at targeted promoters, the dependency on active transcription, and whether or not both strands of the siRNA are required for siRNA-mediated TGS. We report here that siRNA treatment increases both H3K9 and H3K27 methylation of the targeted EF1A promoter and that this increase is dependent on nuclear specific delivery of the siRNA. We also find that TGS can be directed by the antisense strand alone, and requires active transcription by RNA polymerase II in human cells as evidenced by sensitivity to α-amanatin. The observation of antisense strand-specific siRNA-mediated TGS of EF1A was substantiated by targeting the U3 region of the HIV-1 LTR/promoter. Furthermore, we show that the antisense strand of siRNA EF52 associates with the transiently expressed Flag-tagged DNMT3A, the targeted EF1A promoter, and trimethylated H3K27. The observations reported here implicate a functional link between siRNA-mediated targeting of genomic regions (promoters), RNA Pol II function, histone methylation, and DNMT3A and support a paradigm in which the antisense strands of siRNAs alone can direct sequence-specific transcriptional gene silencing in human cells.

Error sources in in-plane silicon tuning-fork MEMS gyroscopes

Abstract: This paper analyzes the error sources defining tactical-grade performance in silicon, in-plane tuning-fork gyroscopes such as the Honeywell-Draper units being delivered for military applications. These analyses have not yet appeared in the literature. These units incorporate crystalline silicon anodically bonded to a glass substrate. After general descriptions of the tuning-fork gyroscope, ordering modal frequencies, fundamental dynamics, force, and fluid coupling, which dictate the need for vacuum packaging, mechanical quadrature, and electrical coupling are analyzed. Alternative strategies for handling these engineering issues are discussed by introducing the Systron Donner/BEI quartz rate sensor, a successful commercial product, and the Analog Device (ADXRS), which is designed for automotive applications.

Working equations for piezoelectric actuators and sensors

Abstract: A new solution to the force, displacements, and charges developed in piezoelectric beams is derived. Differing from previous solutions, this development determines the neutral axis where the bending strains are zero and results in a closed form solution (without matrix inversion). With the closed form, simplifications become evident which increase understanding and facilitate calculations. These equations are than expanded to account for axial, built-in strains in the beam. A design example where axial forces exerted by the piezoelectric layer are important is presented.

Integrative Genomics Viewer

Abstract: Rapid improvements in sequencing and array-based platforms are resulting in a flood of diverse genome-wide data, including data from exome and whole-genome sequencing, epigenetic surveys, expression profiling of coding and noncoding RNAs, single nucleotide polymorphism (SNP) and copy number profiling, and functional assays. Analysis of these large, diverse data sets holds the promise of a more comprehensive understanding of the genome and its relation to human disease. Experienced and knowledgeable human review is an essential component of this process, complementing computational approaches. This calls for efficient and intuitive visualization tools able to scale to very large data sets and to flexibly integrate multiple data types, including clinical data. However, the sheer volume and scope of data pose a significant challenge to the development of such tools.

The emerging role of lncRNAs in cancer

Abstract: It is increasingly evident that many of the genomic mutations in cancer reside inside regions that do not encode proteins. However, these regions are often transcribed into long noncoding RNAs (lncRNAs). The recent application of next-generation sequencing to a growing number of cancer transcriptomes has indeed revealed thousands of lncRNAs whose aberrant expression is associated with different cancer types. Among the few that have been functionally characterized, several have been linked to malignant transformation. Notably, these lncRNAs have key roles in gene regulation and thus affect various aspects of cellular homeostasis, including proliferation, survival, migration or genomic stability. This review aims to summarize current knowledge of lncRNAs from the cancer perspective. It discusses the strategies that led to the identification of cancer-related lncRNAs and the methodologies and challenges involving the study of these molecules, as well as the imminent applications of these findings to the clinic.

Transposable elements and the epigenetic regulation of the genome.

Abstract: Overlapping epigenetic mechanisms have evolved in eukaryotic cells to silence the expression and mobility of transposable elements (TEs). Owing to their ability to recruit the silencing machinery, TEs have served as building blocks for epigenetic phenomena, both at the level of single genes and across larger chromosomal regions. Important progress has been made recently in understanding these silencing mechanisms. In addition, new insights have been gained into how this silencing has been co-opted to serve essential functions in 'host' cells, highlighting the importance of TEs in the epigenetic regulation of the genome.

Micromachined inertial sensors

Abstract: This paper presents a review of silicon micromachined accelerometers and gyroscopes. Following a brief introduction to their operating principles and specifications, various device structures, fabrication, technologies, device designs, packaging, and interface electronics issues, along with the present status in the commercialization of micromachined inertial sensors, are discussed. Inertial sensors have seen a steady improvement in their performance, and today, microaccelerometers can resolve accelerations in the micro-g range, while the performance of gyroscopes has improved by a factor of 10/spl times/ every two years during the past eight years. This impressive drive to higher performance, lower cost, greater functionality, higher levels of integration, and higher volume will continue as new fabrication, circuit, and packaging techniques are developed to meet the ever increasing demand for inertial sensors.