A gene catalogue for post-diapause development of an anhydrobiotic arthropod Artemia franciscana

<p>Abstract</p> <p>Background</p> <p>Diapause is a reversible state of developmental suspension and found among diverse taxa, from plants to animals, including marsupials and some other mammals. Although previous work has accumulated ample data, the molecular mechanism underlying diapause and reactivation from it remain elusive.</p> <p>Results</p> <p>Using <it>Artemia franciscana</it>, a model organism to study the development of post-diapause embryos in Arthropod, we sequenced random clones up to a total of 28,039 ESTs from four cDNA libraries made from dehydrated cysts and three time points after rehydration/reactivation, which were assembled into 8,018 unigene clusters. We identified 324 differentially-expressed genes (DEGs, <it>P </it>< 0.05) based on pairwise comparisons of the four cDNA libraries. We identified a group of genes that are involved in an anti-water-deficit system, including proteases, protease inhibitors, heat shock proteins, and several novel members of the late embryogenesis abundant (LEA) protein family. In addition, we classified most of the up-regulated genes after cyst reactivation into metabolism, biosynthesis, transcription, and translation, and this result is consistent with the rapid development of the embryo. Some of the specific expressions of DEGs were confirmed experimentally based on quantitative real-time PCR.</p> <p>Conclusion</p> <p>We found that the first 5-hour period after rehydration is most important for embryonic reactivation of <it>Artemia</it>. As the total number of expressed genes increases significantly, the majority of DEGs were also identified in this period, including a group of water-deficient-induced genes. A group of genes with similar functions have been described in plant seeds; for instance, one of the novel LEA members shares ~70% amino-acid identity with an <it>Arabidopsis </it>EM (embryonic abundant) protein, the closest animal relative to plant LEA families identified thus far. Our findings also suggested that not only nutrition, but also mRNAs are produced and stored during cyst formation to support rapid development after reactivation.</p

Effects of Absorptive Capacity on Organizational Predisposition Toward Information Systems

This paper draws on the theory of absorptive capacity and related work to identify its dimensions and examine its impact on organizational propensity to adopt novel, complex interorganizational technologies. Specifically, it seeks to examine the causal pathway through which absorptive capacity affects organizational adoption intention. Survey-based research was carried out to test this theory. Data was collected from the CEO, the CFO, and the CIO to measure the level of absorptive capacity and its dimensions, and their intentions to adopt financial electronic data interchange (FEDI). A firm-level structural model was developed. LISREL and PLS were used for testing the measurement and structural models respectively. The results indicate that absorptive capacity’s relationship with adoption intention is mediated by decision-makers’ attitudes toward using FEDI. Preexisting related knowledge and aggressiveness of technology policy contribute significantly to absorptive capacity’s impact on adoption intention. Implications for theory and practice are discussed

Adaptive backstepping control for optimal descent with embedded autonomy

Using Lyapunov stability theory, an adaptive backstepping controller is presented in this paper for optimal descent tracking. Unlike the traditional approach, the proposed control law can cope with input saturation and failure which enables the embedded autonomy of lander system. In addition, this control law can also restrain the unknown bounded terms (i.e., disturbance). To show the controller’s performance in the presence of input saturation, input failure and bounded external disturbance, simulation was carried out under a lunar landing scenario

Functional characterization of the mitochondrial 12S rRNA C1494T mutation associated with aminoglycoside-induced and non-syndromic hearing loss

In this study, we report the biochemical characterization of the deafness-associated mitochondrial 12S rRNA C1494T mutation using 27 cybrid cell lines constructed by transferring mitochondria from 9 lymphoblastoid cell lines derived from a Chinese family into human mitochondrial DNA (mtDNA)-less (ρ°) cells. Six cybrids derived from two asymptomatic members, and nine cybrids derived from three symptomatic members of the Chinese family carrying the C1494T mutation exhibited ∼38 and 43% decrease in the rate of mitochondrial protein labeling, respectively, compared with twelve cybrids derived from four Chinese control individuals. These defects are apparently a primary contributor to significant reductions in the rate of overall respiratory capacity or the rate of malate/glutamate promoted respiration, or succinate/G3P-promoted respiration, or TMPD/ascorbate-promoted respiration in mutant cybrid cell lines derived from either symptomatic or asymptomatic individuals. Furthermore, the very significant/nearly identical increase in the ratio of doubling times in DMDM medium in the presence/absence of high concentration of paromomycin was observed in symptomatic or asymptomatic cybrid cell lines carrying the C1494T mutation as compared with the average rate in control cell lines. These observations provide the direct biochemical evidences that the C1494T mutation is a pathogenic mtDNA mutation associated with aminoglycoside-induced and non-syndromic hearing loss. In addition, these data provide the first biochemical evidence that nuclear background plays a critical role in the phenotypic manifestation of non-syndromic hearing loss and aminoglycoside toxicity associated with the C1494T mutation

Micro- and nano-fluidics around HAB cells

Have you ever wondered how algae stay so clean? Most flowering-plant leaves also stay clean. Under air, films of water and “dirt” are repelled. Repulsion forces the water into droplets that easily roll off because these leaves are covered in hydrophobic nm- to µm- sized grooves and pillars, producing superhydrophobicity (SH) at the surface. Similarly, most algal cells bear a glycocalyx of organic fibrils that give surface structure, and are often hydrophobic. Glycocalyxes serve many functions, but whether they produce SH is poorly known. SH coatings are being developed to prevent fouling of ships and aquaculture structures without using toxins, so this technology could help understand how algae defeat fouling. Glycocalyxes are composed of exopolymeric secretions (EPS), and algae sometimes make the water more viscous using this tightly and more loosely bound EPS. EPS is also sometimes sticky. SH cuticles on copepods may change ambient fluid microdynamics by allowing slip at their surfaces, and facilitate filter feeding. By managing ambient viscosity and surface properties including slipping and sticking, algae may have the tools to engineer ambient fluidics and stay clean and unfouled

A GROUP TECHNOLOGY BASED REPRESENTATION FOR PRODUCT PORTFOLIOS

ABSTRACT Repository based applications for portfolio design offer the potential for leveraging archived design data with computational searches. Toward the development of such search tools, we present a representation for product portfolios that is an extension of an existing Group Technology (GT) coding scheme. Relevance to portfolio design is treated with a case study example of a hand held grinder design. Results of this work provide a numerical coding representation that captures function, form, material and manufacturing data for systems. This extends the current GT line work by combining these four types of design data and clarifying the use of the functional basis in a GT code. The results serve as a useful starting point for the development of portfolio design algorithms, such as genetic algorithms, that account for this combination of design information