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1. Fabrication of bulk piezoelectric and dielectric BaTiO 3 ceramics using paste extrusion 3D printing technique

   https://doi.org/10.1111/jace.16242  

   Kim, Hoejin ; Renteria‐Marquez, Anabel ; Islam, Md Didarul ; Chavez, Luis A. ; Garcia Rosales, Carlos A. ; Ahsan, Md Ariful ; Tseng, Tzu‐Liang Bill ; Love, Norman D. ; Lin, Yirong ( December 2018 , Journal of the American Ceramic Society)

   A simple and facile method was developed to fabricate functional bulk barium titanate (BaTiO₃,BT) ceramics using the paste extrusion 3D printing technique. TheBTceramic is a lead‐free ferroelectric material widely used for various applications in sensors, energy storage, and harvesting. There are several traditional methods (eg, tape casting) to process bulkBTceramics but they have disadvantages such as difficult handing without shape deformation, demolding, complex geometric shapes, expansive molds, etc. In this research, we utilized the paste extrusion 3D printing technique to overcome the traditional issues and developed printable ceramic suspensions containingBTceramic powder, polyvinylidene fluoride (PVDF), N,N‐dimethylformamide (DMF) through simple mixing method and chemical formulation. ThisPVDFsolution erformed multiple roles of binder, plasticizer, and dispersant for excellent manufacturability while providing high volume percent and density of the final bulk ceramic. Based on empirical data, it was found that the maximum binder ratio with good viscosity and retention for desired geometry is 1:8.8, while the maximumBTcontent is 35.45 vol% (77.01 wt%) in order to achieve maximum density of 3.93 g/cm³(65.3%) for 3D printedBTceramic. Among different sintering temperatures, it was observed that the sinteredBTceramic at 1400°C had highest grain growth and tetragonality which affected high performing piezoelectric and dielectric properties, 200 pC/N and 4730 at 10³ Hz respectively. This paste extrusion 3D printing technique and simple synthesis method for ceramic suspensions are expected to enable rapid massive production, customization, design flexibility of the bulk piezoelectric and dielectric devices for next generation technology.

    

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2. All 17 S‐locus F‐box proteins of the S 2 ‐ and S 3 ‐haplotypes of Petunia inflata are assembled into similar SCF complexes with a specific function in self‐incompatibility

   https://doi.org/10.1111/tpj.13222  

   Li, Shu ; Williams, Justin S. ; Sun, Penglin ; Kao, Teh‐hui ( August 2016 , The Plant Journal)

   The collaborative non‐self‐recognition model for S‐RNase‐based self‐incompatibility predicts that multiple S‐locus F‐box proteins (SLFs) produced by pollen of a givenS‐haplotype collectively mediate ubiquitination and degradation of all non‐self S‐RNases, but not self S‐RNases, in the pollen tube, thereby resulting in cross‐compatible pollination but self‐incompatible pollination. We had previously used pollen extracts containingGFP‐fused S₂‐SLF1 (SLF1 with anS₂‐haplotype) ofPetunia inflatafor co‐immunoprecipitation (Co‐IP) and mass spectrometry (MS), and identified PiCUL1‐P (a pollen‐specific Cullin1), PiSSK1 (a pollen‐specific Skp1‐like protein) and PiRBX1 (a conventional Rbx1) as components of theSCF^S2–SLF1complex. Using pollen extracts containing PiSSK1:FLAG:GFPfor Co‐IP/MS, we identified two additionalSLFs (SLF4 andSLF13) that were assembled intoSCF^SLFcomplexes. As 17SLFgenes (SLF1toSLF17) have been identified inS₂andS₃pollen, here we examined whether all 17SLFs are assembled into similar complexes and, if so, whether these complexes are unique toSLFs. We modified the previous Co‐IP/MSprocedure, including the addition of style extracts from four differentS‐genotypes to pollen extracts containing PiSSK1:FLAG:GFP, to perform four separate experiments. The results taken together show that all 17SLFs and anSLF‐like protein,SLFLike1 (encoded by anS‐locus‐linked gene), co‐immunoprecipitated with PiSSK1:FLAG:GFP. Moreover, of the 179 other F‐box proteins predicted byS₂andS₃pollen transcriptomes, only a pair with 94.9% identity and another pair with 99.7% identity co‐immunoprecipitated with PiSSK1:FLAG:GFP. These results suggest thatSCF^SLFcomplexes have evolved specifically to function in self‐incompatibility.

    

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3. Expressed exome capture sequencing: A method for cost‐effective exome sequencing for all organisms

   https://doi.org/10.1111/1755-0998.12905  

   Puritz, Jonathan B. ; Lotterhos, Katie E. ( June 2018 , Molecular Ecology Resources)

   Exome capture is an effective tool for surveying the genome for loci under selection. However, traditional methods require annotated genomic resources. Here, we present a method for creatingcDNAprobes from expressedmRNA, which are then used to enrich and capture genomicDNAfor exon regions. This approach, called “EecSeq,” eliminates the need for costly probe design and synthesis. We tested EecSeq in the eastern oyster,Crassostrea virginica, using a controlled exposure experiment. Four adult oysters were heat shocked at 36°C for 1 hr along with four control oysters kept at 14°C. StrandedmRNAlibraries were prepared for two individuals from each treatment and pooled. Half of the combined library was used for probe synthesis, and half was sequenced to evaluate capture efficiency. GenomicDNAwas extracted from all individuals, enriched via captured probes, and sequenced directly. We found that EecSeq had an average capture sensitivity of 86.8% across all known exons and had over 99.4% sensitivity for exons with detectable levels of expression in themRNAlibrary. For all mapped reads, over 47.9% mapped to exons and 37.0% mapped to expressed targets, which is similar to previously published exon capture studies. EecSeq displayed relatively even coverage within exons (i.e., minor “edge effects”) and even coverage across exonGCcontent. We discovered 5,951SNPs with a minimum average coverage of 80×, with 3,508SNPs appearing in exonic regions. We show that EecSeq provides comparable, if not superior, specificity and capture efficiency compared to costly, traditional methods.

    

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4. Experimentally disentangling the influence of dispersal and habitat filtering on benthic invertebrate community structure

   https://doi.org/10.1111/fwb.12995  

   Brown, Bryan L. ; Wahl, Charles ; Swan, Christopher M. ( September 2017 , Freshwater Biology)

   Ecological communities are structured by a combination of local processes like habitat filtering and species interactions, and regional forces driven by the dispersal of organisms between localities on a landscape. Previous studies suggest that the position of local communities within a dispersal network can greatly influence the relative influence of these two sets of processes on community assembly. However, the majority of previous investigations have used models or inferences based on observational data to investigate these hypotheses, while experiments directly addressing this question have been rare.

   We experimentally investigated the relative influence of local and regional processes in structuring benthic invertebrate communities using artificial streams. We manipulated three factors—source pool for the macroinvertebrate community (headwater vs. mainstem) as a surrogate of network location, habitat complexity (high vs. low) in the flume, and dispersal (high vs. low)—and followed changes in macroinvertebrate community structure for 8 weeks.

   Previous research suggests that because headwater (HW) streams are isolated within river networks,HWs are less influenced by regional processes relative to more well‐connected mainstems (MSs). We therefore predicted (i) that flumes colonised from aHWsource community would respond more strongly to our dispersal treatment than those colonised byMScommunities becauseMSwere already largely structured through dispersal‐driven processes, and (ii) that bothHWandMScommunities would respond to manipulations of local habitat, indicating that responses to the dispersal treatment were a direct result of dispersal driven dynamics rather than specific affinity for conditions in the flumes.

   Both of our predictions were strongly supported by the results of the experiment. For flumes withHWsource pools, the high dispersal treatment had significantly higher diversity than low dispersal flumes. However, this difference only occurred in flumes withHWsource pools and did not occur in flumes withMSsources. There was also strong evidence of community composition inHWflumes shifting significantly towards the macroinvertebrate composition in our experimental dispersal treatment. The major effect of experimental dispersal was to introduce new species in fairly low abundances as would be expected from dispersal via drift over a relatively short time. BothMSandHWcolonised flumes showed highly significant signals of habitat filtering, though the influence of specific habitat differed between the source types.

   These results support the hypothesis that dispersal driven processes are a more important structuring force in well‐connected areas of networks by experimentally demonstrating the responsiveness of previously isolated communities to experimentally induced dispersal. They also demonstrate that this responsiveness is not due to an inherent difference in habitat affinity since source communities from bothHWs andMSs responded to manipulation of habitat variables. This experiment only simulated one type of dispersal process in streams—drifting—and did not include simulated dispersal from other sources, nor did it include population dynamics given the relatively short duration of the experiment. Nevertheless, the sensitivity of previously isolated communities to one type of simulated dispersal is a powerful indication of the mechanisms that structure these systems.

    

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5. Analysis of condensed tannins in Populus spp. using reversed phase UPLC‐PDA‐(−)esi‐MS following thiolytic depolymerisation

   https://doi.org/10.1002/pca.2810  

   Rubert‐Nason, Kennedy F. ; Lindroth, Richard L. ( December 2018 , Phytochemical Analysis)

   Condensed tannins (CTs) are proanthocyanidin heteropolymers that are widely distributed among plants. Their biochemical properties are determined by molecular structure (e.g. polymer size, hydroxylation, stereochemistry). InPopulus, genetically and environmentally‐determined CT concentrations have been related to ecological effects, while the potential role of CT molecular structure has received little attention.

   Evaluate CT polymerisation, major constituent monomers, stereochemistry and overall content inPopulus tremuloidesfoliage using ultra‐high‐performance liquid chromatography with photodiode array and mass spectrometry (UPLC‐PDA‐(−)esi‐MS) detection following thiolytic depolymerisation of the CTs.

   CTs were extracted from dried foliage of sixP. tremuloidesgenotypes into methanol and thiolytically depolymerised into constituent monomers. Calibration standards were prepared by thiolysis of CT mixtures isolated fromP. tremuloidesfoliage on Sephadex LH‐20, followed by preparative high‐performance liquid chromatography (HPLC).

   Populus tremuloidesCTs contained predominantly repeating subunits of three putative stereoisomers each of catechin and gallocatechin. Linear calibrations for standards of these subunits and their thioethers (purities 44–87%, UPLC‐(−)esi‐MS) were generally stable over the course of 10 months. CT polymer size, hydroxylation, stereochemistry and concentrations differed among genotypes.

   This thiolysis‐UPLC‐PDA‐(−)esiMS method was optimised for analysis of CT polymer size, hydroxylation, stereochemistry, and total concentration inPopulusfoliage. It revealed significant variation in each of these properties amongP. tremuloidesgenotypes, and will facilitate evaluation of how environmental factors affect CT molecular structures.

    

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