39 research outputs found

    MY DAY: JOSEPH H. TIMKO

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    Magnetically Triggered Nanocomposite Membranes: A Versatile Platform for Triggered Drug Release

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    Author Manuscript 2012 March 9.Drug delivery devices based on nanocomposite membranes containing thermoresponsive nanogels and superparamagnetic nanoparticles have been demonstrated to provide reversible, on−off drug release upon application (and removal) of an oscillating magnetic field. We show that the dose of drug delivered across the membrane can be tuned by engineering the phase transition temperature of the nanogel, the loading density of nanogels in the membrane, and the membrane thickness, allowing for on-state delivery of model drugs over at least 2 orders of magnitude (0.1−10 μg/h). The zero-order kinetics of drug release across the membranes permit drug doses from a specific device to be tuned according to the duration of the magnetic field. Drugs over a broad range of molecular weights (500−40000 Da) can be delivered by the same membrane device. Membrane-to-membrane and cycle-to-cycle reproducibility is demonstrated, suggesting the general utility of these membranes for drug delivery.Ruth L. Kirschstein National Research Service AwardNational Institutes of Health (U.S.) (Award F32GM096546

    Evolution of a horizontally acquired legume gene, albumin 1, in the parasitic plant Phelipanche aegyptiaca and related species

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    abstract: Background Parasitic plants, represented by several thousand species of angiosperms, use modified structures known as haustoria to tap into photosynthetic host plants and extract nutrients and water. As a result of their direct plant-plant connections with their host plant, parasitic plants have special opportunities for horizontal gene transfer, the nonsexual transmission of genetic material across species boundaries. There is increasing evidence that parasitic plants have served as recipients and donors of horizontal gene transfer (HGT), but the long-term impacts of eukaryotic HGT in parasitic plants are largely unknown. Results Here we show that a gene encoding albumin 1 KNOTTIN-like protein, closely related to the albumin 1 genes only known from papilionoid legumes, where they serve dual roles as food storage and insect toxin, was found in Phelipanche aegyptiaca and related parasitic species of family Orobanchaceae, and was likely acquired by a Phelipanche ancestor via HGT from a legume host based on phylogenetic analyses. The KNOTTINs are well known for their unique “disulfide through disulfide knot” structure and have been extensively studied in various contexts, including drug design. Genomic sequences from nine related parasite species were obtained, and 3D protein structure simulation tests and evolutionary constraint analyses were performed. The parasite gene we identified here retains the intron structure, six highly conserved cysteine residues necessary to form a KNOTTIN protein, and displays levels of purifying selection like those seen in legumes. The albumin 1 xenogene has evolved through >150 speciation events over ca. 16 million years, forming a small family of differentially expressed genes that may confer novel functions in the parasites. Moreover, further data show that a distantly related parasitic plant, Cuscuta, obtained two copies of albumin 1 KNOTTIN-like genes from legumes through a separate HGT event, suggesting that legume KNOTTIN structures have been repeatedly co-opted by parasitic plants. Conclusions The HGT-derived albumins in Phelipanche represent a novel example of how plants can acquire genes from other plants via HGT that then go on to duplicate, evolve, and retain the specialized features required to perform a unique host-derived function.The electronic version of this article is the complete one and can be found online at: http://bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-13-4

    Hydroxyapatite catalyzed hydrothermal liquefaction transforms food waste from an environmental liability to renewable fuel

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    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in LeClerc, H., Tompsett, G., Paulsen, A., McKenna, A., Niles, S., Reddy, C., Nelson, R., Cheng, F., Teixeira, A., & Timko, M. Hydroxyapatite catalyzed hydrothermal liquefaction transforms food waste from an environmental liability to renewable fuel. IScience, 25(9), (2022): 104916, https://doi.org/10.1016/j.isci.2022.104916.Food waste is an abundant and inexpensive resource for the production of renewable fuels. Biocrude yields obtained from hydrothermal liquefaction (HTL) of food waste can be boosted using hydroxyapatite (HAP) as an inexpensive and abundant catalyst. Combining HAP with an inexpensive homogeneous base increased biocrude yield from 14 ± 1 to 37 ± 3%, resulting in the recovery of 49 ± 2% of the energy contained in the food waste feed. Detailed product analysis revealed the importance of fatty-acid oligomerization during biocrude formation, highlighting the role of acid-base catalysts in promoting condensation reactions. Economic and environmental analysis found that the new technology has the potential to reduce US greenhouse gas emissions by 2.6% while producing renewable diesel with a minimum fuel selling price of $1.06/GGE. HAP can play a role in transforming food waste from a liability to a renewable fuel.This work was funded by the DOE Bioenergy Technology Office (DE-EE0008513), a DOE DBIR (DE-SC0015784) and the MassCEC. The authors thank WenWen Yao, Department of Environmental Science at WPI, for TOC analysis, Mainstream Engineering for heating value characterization of the oil and solid samples, Wei Fan for assistance in obtaining SEM images and, Julia Martin and Ronald Grimm for their assistance in collecting XPS data, and Jeffrey R. Page for his assistance with oil upgrading and analysis. HOL was partially funded for this work by NSF Graduate Research Fellowship award number 2038257. A portion of this work was performed at the National High Magnetic Field Laboratory Ion Cyclotron Resonance user facility, which is supported by the NSF Division of Materials Research and Division of Chemistry through DMR 16-44779 and the State of Florida

    The Social Appearance Anxiety Scale in Italian adolescent populations: Construct validation and group discrimination in community and clinical eating disorders samples

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    Anxiety in situations where one’s overall appearance (including body shape) may be negatively evaluated is hypothesized to play a central role in Eating Disorders (EDs) and in their co-occurrence with Social Anxiety Disorder (SAD). Three studies were conducted among community (N = 1995) and clinical (N = 703) ED samples of 11- to 18-year-old Italian girls and boys to (a) evaluate the psychometric qualities and measurement equivalence/invariance (ME/I) of the Social Appearance Anxiety (SAA) Scale (SAAS) and (b) determine to what extent SAA or other situational domains of social anxiety related to EDs distinguish adolescents with an ED only from those with SAD. Results upheld the one-factor structure and ME/I of the SAAS across samples, gender, age categories, and diagnostic status (i.e., ED participants with and without comorbid SAD). The SAAS demonstrated high internal consistency and 3-week test–retest reliability. The strength of the inter-relationships between SAAS and measures of body image, teasing about appearance, ED symptoms, depression, social anxiety, avoidance, and distress, as well as the ability of SAAS to discriminate community adolescents with high and low levels of ED symptoms and community participants from ED participants provided construct validity evidence. Only SAA strongly differentiated adolescents with any ED from those with comorbid SAD (23.2 %). Latent mean comparisons across all study groups were performed and discussed

    Next generation sequencing analysis reveals a relationship between rDNA unit diversity and locus number in <it>Nicotiana</it> diploids

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    Abstract Background Tandemly arranged nuclear ribosomal DNA (rDNA), encoding 18S, 5.8S and 26S ribosomal RNA (rRNA), exhibit concerted evolution, a pattern thought to result from the homogenisation of rDNA arrays. However rDNA homogeneity at the single nucleotide polymorphism (SNP) level has not been detailed in organisms with more than a few hundred copies of the rDNA unit. Here we study rDNA complexity in species with arrays consisting of thousands of units. Methods We examined homogeneity of genic (18S) and non-coding internally transcribed spacer (ITS1) regions of rDNA using Roche 454 and/or Illumina platforms in four angiosperm species, Nicotiana sylvestris, N. tomentosiformis, N. otophora and N. kawakamii. We compared the data with Southern blot hybridisation revealing the structure of intergenic spacer (IGS) sequences and with the number and distribution of rDNA loci. Results and Conclusions In all four species the intragenomic homogeneity of the 18S gene was high; a single ribotype makes up over 90% of the genes. However greater variation was observed in the ITS1 region, particularly in species with two or more rDNA loci, where >55% of rDNA units were a single ribotype, with the second most abundant variant accounted for >18% of units. IGS heterogeneity was high in all species. The increased number of ribotypes in ITS1 compared with 18S sequences may reflect rounds of incomplete homogenisation with strong selection for functional genic regions and relaxed selection on ITS1 variants. The relationship between the number of ITS1 ribotypes and the number of rDNA loci leads us to propose that rDNA evolution and complexity is influenced by locus number and/or amplification of orphaned rDNA units at new chromosomal locations.</p

    Coping and Emotional Intelligence in Women with a History of Eating Disordered Behavior

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    Eating disorders pose a serious problem in our society. Studies have found that there is a negative correlation between eating disorders and emotional coping mechanisms, a factor of emotional intelligence (EI). This study was designed to discover if women who have a history of eating disorders resemble women who report no current or past history of eating disorders and women with current eating problems. Participants included 157 college females. It was found that women who reported a history of eating problems resembled the control group on most measures

    Genome resources for climate‐resilient cowpea, an essential crop for food security

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    [EN] Cowpea (Vigna unguiculata L. Walp.) is a legume crop that is resilient to hot and drought-prone climates, and a primary source of protein in sub-Saharan Africa and other parts of the developing world. However, genome resources for cowpea have lagged behind most other major crops. Here we describe foundational genome resources and their application to the analysis of germplasm currently in use in West African breeding programs. Resources developed from the African cultivar IT97K-499-35 include a whole-genome shotgun (WGS) assembly, a bacterial artificial chromosome (BAC) physical map, and assembled sequences from 4355 BACs. These resources and WGS sequences of an additional 36 diverse cowpea accessions supported the development of a genotyping assay for 51 128 SNPs, which was then applied to five bi-parental RIL populations to produce a consensus genetic map containing 37 372 SNPs. This genetic map enabled the anchoring of 100 Mb of WGS and 420 Mb of BAC sequences, an exploration of genetic diversity along each linkage group, and clarification of macrosynteny between cowpea and common bean. The SNP assay enabled a diversity analysis of materials from West African breeding programs. Two major subpopulations exist within those materials, one of which has significant parentage from South and East Africa and more diversity. There are genomic regions of high differentiation between subpopulations, one of which coincides with a cluster of nodulin genes. The new resources and knowledge help to define goals and accelerate the breeding of improved varieties to address food security issues related to limited-input small-holder farming and climate stressSIDevelopment of the cowpea iSelect was supported by the Feed the Future Innovation Laboratory for Climate Resilient Cowpea (USAID Cooperative Agreement AID-OAA-A-13-00070) and the 2014 Illumina Agricultural Greater Good Initiative. BAC library construction, physical mapping and BAC-end sequencing was supported by the Generation Challenge Program ‘Tropical Legumes 1’ project. MTP BAC sequencing was supported by NSF IIS-1526742 (‘III:Small:Algorithms for Genome Assembly’). Partial support was also provided by Hatch Project CA-R-BPS-5306-H. ‘GSS’ sequencing (Timko et al., 2008) was supported by Kirkhouse Trust. The sequencing and genotyping of Chinese germplasm was partially supported by the National Key Technology Research & Development Program of China (2013BAD01B04-12) and the National Ten-Thousand Talents Program of China (to P. Xu

    NEEDS SEEDED STRATEGIES

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    This paper addresses the issue of developing strategies starting from the identification and comprehension of true consumer needs. Needs and opportunities are linked to markets, benefits and strategies through a specific 3D model based on Maslow�s pyramid. A further model, denoted the PIE (Persons, Institutions and Enterprises), also contextualises needs seeded strategies also for institutions. Furthermore the paper builds on declared and latent needs and the author shows how both can live together, or separately, irrespective whether or not one sees them from the demand or supply side. The argument is that demand strategies are essentially based on declared needs and are �red ocean� in nature while supply strategies pace consumers by hitting latent needs and produce �blue ocean� favoured strategies. It is argued that current strategy frameworks e.g. Porter�s competitive advantage, Wernerfelt�s resourcebased strategy and Hax and Wilde�s integrated competitive advantage models, need to pace rather than chase the consumer. Strategies are considered as being the outcome of strategic choices that enterprises need to answer in order to stay or become (more) competitive. If an enterprise is to build its strategy on satisfying consumer needs then it is necessary to view resources from two perspectives, namely customers and assets. For each one of these two resources three possible scenarios are discussed namely that the resources are Insufficient, Limited or AbundantStrategy, Blue-ocean, Red-ocean, Declared, Latent, Needs
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