Terephthalic acid synthesis at higher concentrations in high-temperature liquid water. 2. Eliminating undesired byproducts

We synthesized terephthalic acid (TPA) from p -xylene at an initial concentration above its solubility limit in high-temperature liquid water (HTW). The nominal p -xylene loading at the reaction conditions was 0.4 mol L −1 , which is the highest reported to date for generation of high TPA yields (>70 mol %) in HTW. The presence of two liquid phases during the reaction did not appear to accelerate the rate, unlike behavior reported for some other organic reactions done “on water” at lower temperatures. Adding oxygen gas in a large increment during synthesis produced a black liquid and a black solid byproduct, which is a previously undocumented problem. Adding oxygen in smaller increments prevented formation of the liquid and solid byproducts and also provided high selectivities (90 mol %) and yields (>70 mol %) of TPA. These results demonstrate the feasibility of HTW as a medium for TPA synthesis at p -xylene concentrations even higher than its solubility limit. © 2009 American Institute of Chemical Engineers AIChE J, 2009Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63001/1/11761_ftp.pd

Alternative trans-splicing of Caenorhabditis elegans sma-9/schnurri generates a short transcript that provides tissue-specific function in BMP signaling

<p>Abstract</p> <p>Background</p> <p>Transcription cofactors related to <it>Drosophila </it>Schnurri facilitate the transcriptional programs regulated by BMP signaling in <it>C. elegans</it>, <it>Drosophila</it>, Xenopus, and mouse. In different systems, Schnurri homologs have been shown to act as either agonists or antagonists of Smad function, and as either positive or negative regulators of transcription. How Schnurri proteins achieve this diversity of activities is not clear. The <it>C. elegans sma-9/schnurri </it>locus undergoes alternative splicing, including an unusual <it>trans</it>-splicing event that could generate two non-overlapping shorter transcripts.</p> <p>Results</p> <p>We demonstrate here that the shorter transcripts are expressed <it>in vivo</it>. Furthermore, we find that one of the short transcripts plays a tissue-specific role in <it>sma-9 </it>function, contributing to the patterning of male-specific sensory rays, but not to the regulation of body size. Based on previous results, we suggest that this transcript encodes a C-terminal SMA-9 isoform that may provide transcriptional activation activity, while full length isoforms may mediate transcriptional repression and/or activation in a context-dependent manner.</p> <p>Conclusion</p> <p>The alternative <it>trans</it>-splicing of <it>sma-9 </it>may contribute to the diversity of functions necessary to mediate tissue-specific outputs of BMP signaling.</p

Lensless high-resolution on-chip optofluidic microscopes for Caenorhabditis elegans and cell imaging

Low-cost and high-resolution on-chip microscopes are vital for reducing cost and improving efficiency for modern biomedicine and bioscience. Despite the needs, the conventional microscope design has proven difficult to miniaturize. Here, we report the implementation and application of two high-resolution (≈0.9 μm for the first and ≈0.8 μm for the second), lensless, and fully on-chip microscopes based on the optofluidic microscopy (OFM) method. These systems abandon the conventional microscope design, which requires expensive lenses and large space to magnify images, and instead utilizes microfluidic flow to deliver specimens across array(s) of micrometer-size apertures defined on a metal-coated CMOS sensor to generate direct projection images. The first system utilizes a gravity-driven microfluidic flow for sample scanning and is suited for imaging elongate objects, such as Caenorhabditis elegans; and the second system employs an electrokinetic drive for flow control and is suited for imaging cells and other spherical/ellipsoidal objects. As a demonstration of the OFM for bioscience research, we show that the prototypes can be used to perform automated phenotype characterization of different Caenorhabditis elegans mutant strains, and to image spores and single cellular entities. The optofluidic microscope design, readily fabricable with existing semiconductor and microfluidic technologies, offers low-cost and highly compact imaging solutions. More functionalities, such as on-chip phase and fluorescence imaging, can also be readily adapted into OFM systems. We anticipate that the OFM can significantly address a range of biomedical and bioscience needs, and engender new microscope applications

Connecting teachers’ language knowledge, perceived ability and instructional practices to Grade 1 students’ literacy outcomes

We examined the associations between teachers’ knowledge of language and literacy constructs, perceived ability to teach early literacy skills, instructional practice, and students’ early reading outcomes. The results showed that teacher knowledge predicted quality of instruction, but neither quality of instruction nor teacher knowledge were associated with stronger decoding or word reading outcomes once earlier decoding skills were controlled. Differentiation of instruction was observed more in classrooms with lower initial decoding skills, and it contributed to better decoding at Time 2. Finally, perceived ability predicted decoding and years of experience predicted word reading at Time 2

Chloride intracellular channel proteins respond to heat stress in Caenorhabditis elegans

Chloride intracellular channel proteins (CLICs) are multi-functional proteins that are expressed in various cell types and differ in their subcellular location. Two CLIC homologs, EXL-1 (excretory canal abnormal like-1) and EXC-4 (excretory canal abnormal± 4), are encoded in the Caenorhabditis elegans genome, providing an excellent model to study the functional diversification of CLIC proteins. EXC-4 functions in excretory canal formation during normal animal development. However, to date, the physiological function of EXL-1 remains largely unknown. In this study, we demonstrate that EXL-1 responds specifically to heat stress and translocates from the cytoplasm to the nucleus in intestinal cells and body wall muscle cells under heat shock. In contrast, we do not observe EXC-4 nuclear translocation under heat shock. Full protein sequence analysis shows that EXL-1 bears a non-classic nuclear localization signal (NLS) that EXC-4 is lacking. All mammalian CLIC members have a nuclear localization signal, with the exception of CLIC3. Our phylogenetic analysis of the CLIC gene families across various animal species demonstrates that the duplication of CLICs in protostomes and deuterostomes occurred independently and that the NLS was subsequently lost in amniotes and nematodes, suggesting convergent evolution. We also observe that EXL-1 nuclear translocation occurs in a timely ordered manner in the intestine, from posterior to anterior regions. Finally, we find that exl-1 loss of function mutants are more susceptible to heat stress than wild-type animals, demonstrating functional relevance of the nuclear translocation. This research provides the first link between CLICs and environmental heat stress. We propose that C. elegans CLICs evolved to achieve different physiological functions through subcellular localization change and spatial separation in response to external or internal signals

The effects of teaching complex grapheme-phoneme correspondences : Evidence from a dual site cluster trial with at-risk Grade 2 students

We evaluated the impact of teaching complex grapheme–phoneme correspondences (GPC) derived from the Simplicity Principle to at-risk poor readers in Grade 2 classrooms, using a two-arm dual site matched control trial intervention. Poor word readers (n = 149) were allocated to either a) Simplicity GPC (n= 79) or b) Letter-Name Control (n= 70) small group reading programs, and received intervention for 12–15 hours over 12 weeks. Students were matched on baseline reading, language, parent demographics, and observed regular classroom teaching quality. Results of hierarchical data modeling showed advantages for the GPC-group for word reading, pseudoword reading, and sentence comprehension at post-test moderated by pre-test phonological awareness skills. The results provide support for teaching complex GPCs derived from the Simplicity Principle as an approach to intervention for word reading, but suggest that children with low PA need additional supports

TGF-β pathways in aging and immunity: lessons from Caenorhabditis elegans

The Transforming Growth Factor-β (TGF-β) superfamily of signaling molecules plays critical roles in development, differentiation, homeostasis, and disease. Due to the conservation of these ligands and their signaling pathways, genetic studies in invertebrate systems including the nematode Caenorhabditis elegans have been instrumental in identifying signaling mechanisms. C. elegans is also a premier organism for research in longevity and healthy aging. Here we summarize current knowledge on the roles of TGF-β signaling in aging and immunity

Risk, ambiguity and quantum decision theory

In the present article we use the quantum formalism to describe the effects of risk and ambiguity in decision theory. The main idea is that the probabilities in the classic theory of expected utility are estimated probabilities, and thus do not follow the classic laws of probability theory. In particular, we show that it is possible to use consistently the classic expected utility formula, where the probability associated to the events are computed with the equation of quantum interference. Thus we show that the correct utility of a lottery can be simply computed by adding to the classic expected utility a new corrective term, the uncertainty utility, directly connected with the quantum interference term.Comment: 1 figur

Potential of heat pipe technology in nuclear seawater desalination

The official published version of this article can be found at the link below.Heat pipe technology may play a decisive role in improving the overall economics, and public perception on nuclear desalination, specifically on seawater desalination. When coupled to the Low-Temperature Multi-Effect Distillation process, heat pipes could effectively harness most of the waste heat generated in various types of nuclear power reactors. Indeed, the potential application of heat pipes could be seen as a viable option to nuclear seawater desalination where the efficiency to harness waste heat might not only be enhanced to produce larger quantities of potable water, but also to reduce the environmental impact of nuclear desalination process. Furthermore, the use of heat pipe-based heat recovery systems in desalination plant may improve the overall thermodynamics of the desalination process, as well as help to ensure that the product water is free from any contamination which occur under normal process, thus preventing operational failure occurrences as this would add an extra loop preventing direct contact between radiation and the produced water. In this paper, a new concept for nuclear desalination system based on heat pipe technology is introduced and the anticipated reduction in the tritium level resulting from the use of heat pipe systems is discussed

The habitats humans provide:factors affecting the diversity and composition of arthropods in houses

Abstract The indoor biome is a novel habitat which recent studies have shown exhibit not only high microbial diversity, but also high arthropod diversity. Here, we analyze findings from a survey of 50 houses (southeastern USA) within the context of additional survey data concerning house and room features, along with resident behavior, to explore how arthropod diversity and community composition are influenced by physical aspects of rooms and their usage, as well as the lifestyles of human residents. We found that indoor arthropod diversity is strongly influenced by access to the outdoors and carpeted rooms hosted more types of arthropods than non-carpeted rooms. Arthropod communities were similar across most room types, but basements exhibited more unique community compositions. Resident behavior such as house tidiness, pesticide usage, and pet ownership showed no significant influence on arthropod community composition. Arthropod communities across all rooms in houses exhibit trophic structure—with both generalized predators and scavengers included in the most frequently found groups. These findings suggest that indoor arthropods serve as a connection to the outdoors, and that there is still much yet to be discovered about their impact on indoor health and the unique ecological dynamics within our homes