Whole transcriptome analysis of the coral Acropora millepora reveals complex responses to CO2-driven acidification during the initiation of calcification.

The impact of ocean acidification (OA) on coral calcification, a subject of intense current interest, is poorly understood in part because of the presence of symbionts in adult corals. Early life history stages of Acropora spp. provide an opportunity to study the effects of elevated CO(2) on coral calcification without the complication of symbiont metabolism. Therefore, we used the Illumina RNAseq approach to study the effects of acute exposure to elevated CO(2) on gene expression in primary polyps of Acropora millepora, using as reference a novel comprehensive transcriptome assembly developed for this study. Gene ontology analysis of this whole transcriptome data set indicated that CO(2) -driven acidification strongly suppressed metabolism but enhanced extracellular organic matrix synthesis, whereas targeted analyses revealed complex effects on genes implicated in calcification. Unexpectedly, expression of most ion transport proteins was unaffected, while many membrane-associated or secreted carbonic anhydrases were expressed at lower levels. The most dramatic effect of CO(2) -driven acidification, however, was on genes encoding candidate and known components of the skeletal organic matrix that controls CaCO(3) deposition. The skeletal organic matrix effects included elevated expression of adult-type galaxins and some secreted acidic proteins, but down-regulation of other galaxins, secreted acidic proteins, SCRiPs and other coral-specific genes, suggesting specialized roles for the members of these protein families and complex impacts of OA on mineral deposition. This study is the first exhaustive exploration of the transcriptomic response of a scleractinian coral to acidification and provides an unbiased perspective on its effects during the early stages of calcification.

Effectiveness of frequency mapping on 28 nm device broken scan chain failures.

Frequency mapping methodology is an effective diagnostic tool for detection of manufacturing defects in scan chains. It analyses reflected laser modulations from toggling scan cells to localize defective scan path or scan cell. In this paper, we demonstrate experimentally that the use of solid immersion lens technology to enhance signal and spatial resolution is not a prerequisite for this technique up till 28 nm technology node. We present case studies to show the effectiveness of frequency mapping for detecting systematic and random broken scan chain failures on a 28 nm technology node test chip. We achieved 81% success rate in this methodology.

Design considerations for refractive solid immersion lens: application to subsurface integrated circuit fault localization using laser induced techniques.

With fast scaling and advancement of integrated circuit (IC) technology, circuitries have become smaller and denser. New materials and more sophisticated designs have evolved. These changes reduced the effectiveness of conventional laser induced fault localization techniques. Since IC fault localization is the most critical step in failure analysis, there are strong motivations to improve both spatial resolution and sensitivity of such systems to meet the new challenges from advanced technology. Refractive solid immersion lens (RSIL) is well known to enhance the laser spot size which directly affects resolution and sensitivity in back side fault localizations. In practice, it is difficult to operate RSIL at the ideal configurations to obtain the smallest spot resolution. It is necessary to understand the resolution performance at the other design focal planes. Besides resolution, there are also other factors that affect sensitivity in a RSIL enhanced system. This paper identifies and characterizes key RSIL design parameters to optimize RSIL performance on laser induced techniques. We report that the most efficient conditions are achieved close to aplanatic RSIL design to within 20-25 microm (for a 1 mm diameter lens), and the backing objective should be the minimum numerical aperture required for optimum resolution performance. The size of the mechanical clear aperture opening should be large enough (>80%) to exploit the advantage of aplanatic RSIL. RSIL is developed on a laser scanning optical microscope in this work, and a resolution of 0.3 microm (for a wavelength of 1340 nm) was achieved over a range of operating conditions. A quantitative resolution of 0.25 microm is achieved and a pitch structure of 0.4 microm is easily resolvable. Close to 15 times enhancement in laser induced signal is obtained.