726 research outputs found

    Enhancement of Water Transport and Microstructural Changes Induced by High-Intesity Ultrasound Application on Orange Peel Drying

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    The main aim of this work was to evaluate the effect of high-intensity ultrasound (US) on the drying kinetics of orange peel as well as its influence on the microstructural changes induced during drying. Convective drying kinetics of orange peel slabs were carried out at a relative humidity of 26.5±0.9%, 40 °C and 1 m/s with (AIR+US) and without (AIR) ultrasound application. In order to identify the US effect on water transport, drying kinetics were analyzed by taking the diffusion theory into account. Fresh, AIR and AIR+US dried samples were analyzed using Cryo-Scanning Electron Microscopy. Results showed that the drying kinetics of orange peel were significantly improved by US application, which involved a significant (p<0.05) improvement of mass transfer coefficient and effective moisture diffusivity. The effects on mass transfer properties were confirmed with microstructural observations. In the cuticle surface of flavedo, the pores were obstructed by the spread of the waxy components, this fact evidencing US effects on the air solid interfaces. Furthermore, the cells of the albedo were disrupted by US, as it created large intercellular air spaces facilitating water transfer through the tissue.The authors would like to acknowledge the financial support of MICINN and CEE (European Regional Development Fund) from projects Ref. DPI2009-14549-C04-04, PSE-060000-2009-003, and FP6-2004-FOOD-23140 HIGHQ RTE.GarcĂ­a PĂ©rez, JV.; Ortuño Cases, C.; Puig GĂłmez, CA.; CĂĄrcel CarriĂłn, JA.; PĂ©rez Munuera, IM. (2012). Enhancement of Water Transport and Microstructural Changes Induced by High-Intesity Ultrasound Application on Orange Peel Drying. Food and Bioprocess Technology. 5(6):2256-2265. https://doi.org/10.1007/s11947-011-0645-0S2256226556Alandes, L., Perez-Munuera, I., Llorca, E., Quiles, A., & Hernando, I. (2009). 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    Cell walls of the dimorphic fungal pathogens Sporothrix schenckii and Sporothrix brasiliensis exhibit bilaminate structures and sloughing of extensive and intact layers

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    This work was supported by the Fundação Carlos Chagas de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), grants E-26/202.974/2015 and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), grants 229755/2013-5, Brazil. LMLB is a senior research fellow of CNPq and Faperj. NG acknowledged support from the Wellcome Trust (Trust (097377, 101873, 200208) and MRC Centre for Medical Mycology (MR/N006364/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Developing country consumers’ acceptance of biofortified foods: a synthesis

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    The success of biofortified staple crops depends on whether they are accepted and consumed by target populations. In the past 8 years, several studies were undertaken to understand consumers’ acceptance of foods made with biofortified staple crops. Consumer acceptance is measured in terms of their sensory evaluation and economic valuation of biofortified varieties vis-à-vis conventional ones. These studies apply expert sensory panel and hedonic trait analyses methods adopted from food sciences literature, as well as various preference elicitation methods (including experimental auctions, revealed choice experiments, and stated choice experiments) adopted from experimental economics literature. These studies also test the impact of various levers on consumers’ evaluation and valuation for biofortified foods. These levers include (i) nutrition information and the media through which such information is conveyed; (ii) the length and content of nutrition information; (iii) different branding options; (iv) the nature (national or international) of the branding/certification agency that is endorsing the biofortified staple food; and (v) the nature (national or international) of the agency that is delivering the biofortified staple food. This paper brings together evidence on consumer acceptance of biofortified crops on 5 crops across 7 countries in Africa, Asia and Latin America. The results of these studies are expected to aid in the development of biofortified crops that consumers like, as well as in the development of appropriate marketing and consumer awareness or information campaigns to encourage the switch in consumption from traditional staples to biofortified ones

    Endonuclease-independent LINE-1 retrotransposition at mammalian telomeres

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    Long interspersed element-1 (LINE-1 or L1) elements are abundant, non-long-terminal-repeat (non-LTR) retrotransposons that comprise 17% of human DNA(1). The average human genome contains similar to 80-100 retrotransposition- competent L1s (ref. 2), and they mobilize by a process that uses both the L1 endonuclease and reverse transcriptase, termed target-site primed reverse transcription(3-5). We have previously reported an efficient, endonuclease-independent L1 retrotransposition pathway (ENi) in certain Chinese hamster ovary (CHO) cell lines that are defective in the non-homologous end-joining (NHEJ) pathway of DNA double-strand-break repair(6). Here we have characterized ENi retrotransposition events generated in V3 CHO cells, which are deficient in DNA-dependent protein kinase catalytic subunit (DNA-PKcs) activity and have both dysfunctional telomeres and an NHEJ defect. Notably, similar to 30% of ENi retrotransposition events insert in an orientation-specific manner adjacent to a perfect telomere repeat (5'-TTAGGG-3'). Similar insertions were not detected among ENi retrotransposition events generated in controls or in XR-1 CHO cells deficient for XRCC4, an NHEJ factor that is required for DNA ligation but has no known function in telomere maintenance. Furthermore, transient expression of a dominant-negative allele of human TRF2 ( also called TERF2) in XRCC4-deficient XR-1 cells, which disrupts telomere capping, enables telomere-associated ENi retrotransposition events. These data indicate that L1s containing a disabled endonuclease can use dysfunctional telomeres as an integration substrate. The findings highlight similarities between the mechanism of ENi retrotransposition and the action of telomerase, because both processes can use a 3' OH for priming reverse transcription at either internal DNA lesions or chromosome ends(7,8). Thus, we propose that ENi retrotransposition is an ancestral mechanism of RNA-mediated DNA repair associated with non-LTR retrotransposons that may have been used before the acquisition of an endonuclease domain.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62964/1/nature05560.pd

    L1TD1 Is a Marker for Undifferentiated Human Embryonic Stem Cells

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    Human embryonic stem cells (hESC) are stem cells capable of differentiating into cells representative of the three primary embryonic germ layers. There has been considerable interest in understanding the mechanisms regulating stem cell pluripotency, which will ultimately lead to development of more efficient methods to derive and culture hESC. In particular, Oct4, Sox2 and Nanog are transcription factors known to be important in maintenance of hESC. However, many of the downstream targets of these transcription factors are not well characterized. Furthermore, it remains unknown whether additional novel stem cell factors are involved in the establishment and maintenance of the stem cell state.Here we show that a novel gene, L1TD1 (also known as FLJ10884 or ECAT11), is abundantly expressed in undifferentiated hESC. Differentiation of hESC via embryoid body (EB) formation or BMP4 treatment results in the rapid down-regulation of L1TD1 expression. Furthermore, populations of undifferentiated and differentiated hESC were sorted using the stem cell markers SSEA4 and TRA160. Our results show that L1TD1 is enriched in the SSEA4-positive or TRA160-positive population of hESC. Using chromatin immunoprecipitation we found enriched association of Nanog to the predicted promoter region of L1TD1. Furthermore, siRNA-mediated knockdown of Nanog in hESC also resulted in downregulation of L1TD1 expression. Finally, using luciferase reporter assay we demonstrated that Nanog can activate the L1TD1 upstream promoter region. Altogether, these results provide evidence that L1TD1 is a downstream target of Nanog.Taken together, our results suggest that L1TD1 is a downstream target of Nanog and represents a useful marker for identifying undifferentiated hESC

    Defending the genome from the enemy within:mechanisms of retrotransposon suppression in the mouse germline

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    The viability of any species requires that the genome is kept stable as it is transmitted from generation to generation by the germ cells. One of the challenges to transgenerational genome stability is the potential mutagenic activity of transposable genetic elements, particularly retrotransposons. There are many different types of retrotransposon in mammalian genomes, and these target different points in germline development to amplify and integrate into new genomic locations. Germ cells, and their pluripotent developmental precursors, have evolved a variety of genome defence mechanisms that suppress retrotransposon activity and maintain genome stability across the generations. Here, we review recent advances in understanding how retrotransposon activity is suppressed in the mammalian germline, how genes involved in germline genome defence mechanisms are regulated, and the consequences of mutating these genome defence genes for the developing germline

    Characterization of LINE-1 Ribonucleoprotein Particles

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    The average human genome contains a small cohort of active L1 retrotransposons that encode two proteins (ORF1p and ORF2p) required for their mobility (i.e., retrotransposition). Prior studies demonstrated that human ORF1p, L1 RNA, and an ORF2p-encoded reverse transcriptase activity are present in ribonucleoprotein (RNP) complexes. However, the inability to physically detect ORF2p from engineered human L1 constructs has remained a technical challenge in the field. Here, we have employed an epitope/RNA tagging strategy with engineered human L1 retrotransposons to identify ORF1p, ORF2p, and L1 RNA in a RNP complex. We next used this system to assess how mutations in ORF1p and/or ORF2p impact RNP formation. Importantly, we demonstrate that mutations in the coiled-coil domain and RNA recognition motif of ORF1p, as well as the cysteine-rich domain of ORF2p, reduce the levels of ORF1p and/or ORF2p in L1 RNPs. Finally, we used this tagging strategy to localize the L1–encoded proteins and L1 RNA to cytoplasmic foci that often were associated with stress granules. Thus, we conclude that a precise interplay among ORF1p, ORF2p, and L1 RNA is critical for L1 RNP assembly, function, and L1 retrotransposition

    The Microprocessor controls the activity of mammalian retrotransposons

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    More than half of the human genome is made of transposable elements whose ongoing mobilization is a driving force in genetic diversity; however, little is known about how the host regulates their activity. Here, we show that the Microprocessor (Drosha-DGCR8), which is required for microRNA biogenesis, also recognizes and binds RNAs derived from human long interspersed element 1 (LINE-1), Alu and SVA retrotransposons. Expression analyses demonstrate that cells lacking a functional Microprocessor accumulate LINE-1 mRNA and encoded proteins. Furthermore, we show that structured regions of the LINE-1 mRNA can be cleaved in vitro by Drosha. Additionally, we used a cell culture–based assay to show that the Microprocessor negatively regulates LINE-1 and Alu retrotransposition in vivo. Altogether, these data reveal a new role for the Microprocessor as a post-transcriptional repressor of mammalian retrotransposons and a defender of human genome integrity.S.R.H. was supported by a Marie Curie Intra-European Fellowship and a Marie Curie CIG-Grant (PCIG10-GA-2011-303812). M.P. and E.E. were supported by the Spanish Ministry of Science (BIO2011-23920) and by the Sandra Ibarra Foundation (CSD2009-00080). M.P. is supported by the Novo Nordisk Foundation. J.L.G.-P. is supported by FP7-PEOPLE-2007-4-3-IRG, CICE-FEDER-P09-CTS-4980, PeS-FEDER-PI-002, FIS-FEDER-PI11/01489 and the Howard Hughes Medical Institute (IECS-55007420). J.F.C. was supported by Core funding from the Medical Research Council and by the Wellcome Trust (grant 095518/B/11/Z)

    Dry Needling for Spine Related Disorders: a Scoping Review

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    Introduction/Background: The depth and breadth of research on dry needling (DN) has not been evaluated specifically for symptomatic spine related disorders (SRD) from myofascial trigger points (TrP), disc, nerve and articular structures not due to serious pathologies. Current literature appears to support DN for treatment of TrP. Goals of this review include identifying research published on DN treatment for SRD, sites of treatment and outcomes studied. Methods: A scoping review was conducted following Levac et al.’s five part methodological framework to determine the current state of the literature regarding DN for patients with SRD. Results: Initial and secondary search strategies yielded 55 studies in the cervical (C) region (71.43%) and 22 in the thoracolumbar-pelvic (TLP) region (28.57%). Most were randomized controlled trials (60% in C, 45.45% in TLP) and clinical trials (18.18% in C, 22.78% in TLP). The most commonly treated condition was TrP for both the C and TLP regions. In the C region, DN was provided to 23 different muscles, with the trapezius as treatment site in 41.88% of studies. DN was applied to 31 different structures in the TLP region. In the C region, there was one treatment session in 23 studies (41.82%) and 2–6 treatments in 25 (45.45%%). For the TLP region, one DN treatment was provided in 8 of the 22 total studies (36.36%) and 2–6 in 9 (40.9%). The majority of experimental designs had DN as the sole intervention. For both C and TLP regions, visual analogue scale, pressure pain threshold and range of motion were the most common outcomes. Conclusion: For SRD, DN was primarily applied to myofascial structures for pain or TrP diagnoses. Many outcomes were improved regardless of diagnosis or treatment parameters. Most studies applied just one treatment which may not reflect common clinical practice. Further research is warranted to determine optimal treatment duration and frequency. Most studies looked at DN as the sole intervention. It is unclear whether DN alone or in addition to other treatment procedures would provide superior outcomes. Functional outcome tools best suited to tracking the outcomes of DN for SRD should be explored.https://doi.org/10.1186/s12998-020-00310-
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