76 research outputs found

    Genetic variation in the emblematic Puya raimondii (Bromeliaceae) from Huascarán National Park, Peru

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    Puya raimondii, the giant Peruvian and Bolivian terrestrial bromeliad, is an emblematic endemic Andean species well represented in Huascarán National Park in Peru. This park is the largest reserve of puna (high altitude plateau) vegetation. The objective of this study is to report on genetic variation in populations of P. raimondii from Huascarán and neighboring areas. AFLP profiles with four selective primer combinations were retrieved for 60 individuals from different zones. Genetic variability was estimated and a total of 172 bands were detected, of which 79.1% were polymorphic loci. The results showed genetic differentiation among populations, and gene flow. A cluster analysis showed that individuals of P. raimondii populations located in different mountain systems could be grouped together, suggesting long distance dispersal. Thus, conservation strategies for P. raimondii have to take into account exchange between populations located far apart in distance in order to preserve the genetic diversity of this showy species

    Navigating Relationships and Boundaries: Concerns around ICT-uptake for Elderly People

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    Despite a proliferation of research in the use of ICTs to support active and healthy ageing, few have considered the privacy and security concerns particular to the elderly. We investigated the appropriation of tablet devices and a neighborhood portal as well as emerging privacy and security issues through ethnographic and action research in a long-term participatory design (PD) project with elderly participants. We discuss two major themes: a) the tensions related to perceived digital threats and the social pressures of online disclosure to the social environment; and b) the relation of these issues to the ICT appropriation process and the referring challenges we encountered. We argue that there is a need to understand the interleaving of physical and virtual habitats, the various ways resulting in discomfort and the senior citizens' actions – which at first glance appear contradictory. We consider the implications of the issues observed for examining privacy and security concerns more broadly as well as discussing implications for the design of the portal and the shaping of social measures for appropriation support

    Comparative investigation on the value-added products obtained from continuous and batch hydrothermal liquefaction of sewage sludge

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    Hydrothermal liquefaction (HTL) can be considered a promising route for the energy valorisation of waste sewage sludge (SS). However, not much information is available on continuous flow processing. In this study, the mixed SS was subjected to HTL at 350°C for 8 min in a continuous reactor with loadings of 10 wt% in the feed flow. The results show that the mass recovery reached 88%, with a biocrude yield of 30.8 wt% (3.9 wt% N content). The recovered biocrude yields are highly dependent on the selection of the recovery solvent for extraction, and dichloromethane can contribute an additional 3.1 wt% biocrude from aqueous phase, acetone can extract some pyrrole derivatives into the trapped phases. Comparable results were also achieved by performing batch reactions under the same conditions: a slightly higher biocrude yield (33.1 wt%) with an N content of 4.3 wt%. The higher N content observed in the biocrude from the batch process indicates that interactions and chelation between intermediates are enhanced during heating up and cooling period, which lead to more N-containing compounds

    From Double-Pancake Coils to a Layer Wound 5 T REBCO-HTS High Field Insert Coil Design

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    Impedimetric Biosensor Based on a Hechtia argentea Lectin for the Detection of Salmonella spp.

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    A sensitive electrochemical detection method for Salmonella spp. was described, based on the use of Hechtia argentea lectin immobilised on a screen-printed gold electrode. The lectin was extracted from Hechtia argentea, a plant belonging to the Bromeliaceae family. The lectin with molecular weight near 27.4 kDa showed selectivity towards D-mannose, contained on the lipopolysaccharide cell wall of Salmonella spp. Carbohydrate selectivity of the lectin was measured as a change in impedance with respect to concentration. The binding of the bacteria to the biosensor surface increased impedance with increasing concentrations of Salmonella spp., achieving a linear range of detection of 15–2.57 × 107 CFU mL−1, with a limit of detection of 5 CFU mL−1. Increases in impedance were measured using electrochemical impedance spectroscopy and analysed using Nyquist plots. The biosensor was applied in analysis of hen egg samples, and the results were consistent with those obtained using the official analysis methodologyS

    A dual-flow RootChip enables quantification of bi-directional calcium signalling in primary roots

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    One sentence summary: Bi-directional-dual-flow-RootChip to track calcium signatures in Arabidopsis primary roots responding to osmotic stress. Plant growth and survival is fundamentally linked with the ability to detect and respond to abiotic and biotic factors. Cytosolic free calcium (Ca2+) is a key messenger in signal transduction pathways associated with a variety of stresses, including mechanical, osmotic stress and the plants’ innate immune system. These stresses trigger an increase in cytosolic Ca2+ and thus initiate a signal transduction cascade, contributing to plant stress adaptation. Here we combine fluorescent G-CaMP3 Arabidopsis thaliana sensor lines to visualise Ca2+ signals in the primary root of 9-day old plants with an optimised dual-flow RootChip (dfRC). The enhanced polydimethylsiloxane (PDMS) bi-directionaldual-flow-RootChip (bi-dfRC) reported here adds two adjacent inlet channels at the base of the observation chamber, allowing independent or asymmetric chemical stimulation at either the root differentiation zone or tip. Observations confirm distinct early spatio-temporal patterns of salinity (sodium chloride, NaCl) and drought (polyethylene glycol, PEG)-induced Ca2+ signals throughout different cell types dependent on the first contact site. Furthermore, we show that the primary signal always dissociates away from initially stimulated cells. The observed early signaling events induced by NaCl and PEG are surprisingly complex and differ from long-term changes in cytosolic Ca2+ reported in roots. Bi-dfRC microfluidic devices will provide a novel approach to challenge plant roots with different conditions simultaneously, while observing bi-directionality of signals. Future applications include combining the bi-dfRC with H2O2 and redox sensor lines to test root systemic signaling responses to biotic and abiotic factors

    The Janthinobacterium sp. HH01 genome encodes a homologue of the V. cholerae CqsA and L. pneumophila LqsA autoinducer synthases

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    Janthinobacteria commonly form biofilms on eukaryotic hosts and are known to synthesize antibacterial and antifungal compounds. Janthinobacterium sp. HH01 was recently isolated from an aquatic environment and its genome sequence was established. The genome consists of a single chromosome and reveals a size of 7.10 Mb, being the largest janthinobacterial genome so far known. Approximately 80% of the 5,980 coding sequences (CDSs) present in the HH01 genome could be assigned putative functions. The genome encodes a wealth of secretory functions and several large clusters for polyketide biosynthesis. HH01 also encodes a remarkable number of proteins involved in resistance to drugs or heavy metals. Interestingly, the genome of HH01 apparently lacks the N-acylhomoserine lactone (AHL)-dependent signaling system and the AI-2-dependent quorum sensing regulatory circuit. Instead it encodes a homologue of the Legionella- and Vibrio-like autoinducer (lqsA/cqsA) synthase gene which we designated jqsA. The jqsA gene is linked to a cognate sensor kinase (jqsS) which is flanked by the response regulator jqsR. Here we show that a jqsA deletion has strong impact on the violacein biosynthesis in Janthinobacterium sp. HH01 and that a jqsA deletion mutant can be functionally complemented with the V. cholerae cqsA and the L. pneumophila lqsA genes

    The Reserva de la Biosfera Barranca de Metztitlán (Hidalgo): An illustrated checklist of bromeliads and orchids and their high levels of Mexican endemisms

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    This study presents a list of species of the two most important families with epiphytic elements, Bromeliaceae and Orchidaceae, from the Reserva de la Biosfera Barranca de Metztitlán (RBBM), the largest Reserve in Hidalgo, Mexico. Thirty-four species are included, 26 corresponding to species in three genera of bromeliads, and eight species in six genera of orchids. The new records represent 26.5% of the total listed in the area; nine of them are new records for the Reserve (RBBM) and one is new for Hidalgo State. This study reveals that endemism for both families is very important in the Reserve (55.88%), since it includes 13 Mexican bromeliads, of which two are endemic to Hidalgo and one to the Reserve, and three orchids, two endemic to Mexico and one to the Reserve. We found species with different types of relative abundance: rare (16) and occasional (7). Additionally, we include information about the category (IUCN, CITES, NOM-059-SEMARNAT) as well as uses reported in the literature for the species in the RBBM. The checklist is strictly based on information obtained from deposited herbarium specimens as well as from those collected during fieldwork. We suggest that a conservation plan (in situ and ex situ) for the RBBM is important and necessary. The predominant habit for both families is epiphytic (17 species); even though there are terrestrial (7) and saxicolous (2), and the remaining are facultative species (8). Nine species are included in some risk category. The present work is the most complete and updated list of Bromeliaceae and Orchidaceae for this important natural area in the Mexican State of Hidalgo. However, more fieldwork is needed to document the biodiversity of the area in general and its flora in particular, as a way to highlight the importance of protected areas in preserving biodiversity

    Perceptions and attitudes of bicyclists towards self-driving cars: a mixed methods approach

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    Efforts to advance Autonomous Vehicles (AVs) have taken on a central role in research and development in recent years and will have a significant influence on road traffic in the future. Research on AVs has mainly focused on the technology itself and the direct users of AVs and their acceptance. However, the role of bicyclists, interacting with AVs in traffic, is not yet researched as thoroughly. Using a mixed methods approach, we combine quantitative results from a survey among bicyclists (N = 889) and qualitative results from a focus group (N = 19) to give insights into bicyclists’ attitudes and expectations towards self-driving cars. The results showed that bicyclists’ affinity for technology is a significant predictor for both their trust and perceived safety towards self-driving cars, as well as an effect of age and gender on these variables. Both from the quantitative and qualitative results, it is clear that flawless functioning of the technology of AVs is a prerequisite for bicyclists encountering and interacting with AVs in traffic, and that the status of the vehicle (autonomous vs. non-autonomous) is very important as well as easy to understand signals that indicate the next manoeuvres of the AV. For supporting interaction with AVs, we found that bicyclists are open to External Human Machine Interface (eHMI) solutions, as long as these ensure inclusion and support the easily-accessible nature of bicycling. Our findings can inform the design of eHMIs that help shape the interaction between bicyclists and AVs in the future, and provide insights on which factors determine the perception of AVs and, ultimately, the acceptance of AVs as part of road traffic
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