2,377 research outputs found

    Dietary fibre and cell-wall polysaccharides in chaenomeles fruits

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    In this paper, research on dietary fibre and cell-wall polysaccharides in chaenomeles fruits is reported and summarised. The dietary fibre in fruits of 12 genotypes of Japanese quince (Chaenomeles japonica) and 1 genotype of flowering quince (C. speciosa) was prepared using two different methods: the Alcohol Insoluble Solid (AIS) method; and the AOAC method for total as well as for soluble and insoluble fibre. The two methods resulted in significantly different estimates, however, no interaction was found between the methods and the genotypes studied. For content of total dietary fibre, three main groups were distinguished, one containing a low amount of fibre (3 genotypes, 28–30 g/100 g dry matter); one containing a moderate amount of fibre (9 genotypes, 30–36 g/100 g dry matter) and an isolated genotype (C. speciosa) that contained a high amount of fibre (38 g/100 g dry matter). The amount and the nature of monomeric sugars in the constituent polysaccharides of the fibre were determined after total hydrolysis of the AIS and the TDF (Total Dietary Fibre). The fibre contained mostly pectic and cellulosic polysaccharides. A sequential extraction scheme allowed the separation of the cell-wall material into its major components (cellulose, pectins and hemicelluloses). The AIS was composed of 30 g pectins, 8 g hemicelluloses and 60 g cellulosic residue/100 g AIS. In 100 g entire dry fruit (800 g entire fresh fruit) there were 11 g pectins, 3 g hemicelluloses and 18 g cellulosic residue. Pectins were mostly located in the flesh of the fruit. Pectins were more efficiently extracted with hot dilute acid than with other extraction media. Pectins had a high degree of methylation (DM) and a low degree of acetylation (DAc). No difference was found in the quantity of polysaccharides extracted from two Japanese quince genotypes, or in the composition of these constituent polysaccharides. The physico-chemical properties of pectins extracted from two genotypes of Japanese quince were studied. On average, the fruits contained 11 g pectins/100 g dry fruit corresponding to 1.4 g pectins/100 g fresh fruit. Pectins were sequentially extracted, and the cells from the flesh of the fruits were observed with a confocal laser scan microscope. Although the dilute acid conditions were the most efficient for extraction of pectins, pectins extracted by water or potassium oxalate had higher (> 600 ml/g) intrinsic viscosities than pectins extracted by dilute acid (< 400 ml/g). Anionic exchange chromatography was performed on the acid-extracted pectins. The pectins were composed of four populations, the first being mainly composed of arabinans, the second of homogalacturonans and the third of rhamnogalacturonans. The composition of the fourth population differed depending on the genotype studied

    Constraints on the variability of quark masses from nuclear binding

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    Based on recent work on nuclear binding, we update and extend the anthropic constraints on the light quark masses, with results that are more tightly constrained than previously obtained. We find that heavy nuclei would fall apart (because the attractive nuclear central potential becomes too weak) if the sum of the light quark masses m_u+m_d would exceed their physical values by 64% (at 95% confidence level). We summarize the anthropic constraints that follow from requiring the existence both of heavy atoms and of hydrogen. With the additional assumption that the quark Yukawa couplings do not vary, these constraints provide a remarkably tight anthropic window for the Higgs vacuum expectation value: 0.39 < v/v_physical < 1.64.Comment: 21 pages, 7 figure

    One size does not fit all: Identifying clusters of physical activity, screen time, and sleep behaviour co-development from childhood to adolescence

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    Purpose Canada was the first to adopt comprehensive 24-h movement guidelines that include recommendations for physical activity, screen time and sleep to promote health benefits. No studies have investigated the concurrent development of these behaviours in youth. The objectives were to assess adherence to the Canadian 24-h movement guidelines for children and youth and estimate co-development of self-reported moderate-to-vigorous intensity physical activity (MVPA), screen time and sleep during 8-years from childhood to adolescence. Methods Nine hundred and twenty three participants of the MATCH study self-reported their MVPA, screen time and sleep duration at least twice over 8 years. MVPA and screen time were measured three times per year (24 cycles), and sleep was measured once per year (8 cycles). Guideline adherence was dichotomised as meeting each specific health behaviour recommendation or not. Multi-group trajectory modeling was used to identify unique trajectories of behavioural co-development. Analyses were stratified by sex. Results Between 10 and 39% of youth did not meet any recommendation at the various cycles of data collection. More than half of youth met only one or two recommendation, and roughly 5% of participants met all three recommendations at one or more study cycle throughout the 8 years of follow-up. Four different trajectories of behavioural co-development were identified for boys and for girls. For boys and girls, a complier (good adherence to the guideline recommendations; 12% boys and 9% girls), a decliner (decreasing adherence to the guideline recommendations; 23% boys and 18% girls) and a non-complier group (low adherence to the guideline recommendations; 42% boys and 42% girls) were identified. In boys, a MVPA-complier group (high MVPA-low screen time; 23%) was identified, whereas in girls a screen-complier group (moderate screen time-low MVPA; 30%) was identified. Conclusions There is a need to recognise that variations from general trends of decreasing MVPA, increasing screen time and decreasing sleep exist. Specifically, we found that although it is uncommon for youth to adhere to the Canadian 24-h movement guidelines, some youth displayed a high likelihood of attaining one or multiple of the behavioural recommendations. Further, patterns of adherence to the guidelines can differ across different sub-groups of youth

    The Voices of History: theorising the interpersonal semantics of historical discourses

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    ‘The individual consumer, the learner of history, is offered an impressive array of discursive products geared to catch his or her attention, to persuade him or her of the truth of whatever message is transmitted’ (Blanco and Rosa 1997: 197. In this article I examine these discursive products from the perspective of ‘voice’. I do this as a way of bringing to conscious attention the strategies that historians use in order to persuade and position the ‘consumer’. ‘Voice’ in recent systemic linguistic theorizing refers to distinctive configurations of APPRAISAL choices. Within the domain of history, research to date has identified three main configurations or voices—‘recorder’, ‘interpreter’, and ‘adjudicator’. Central to the research reported on in this article is Martin’s APPRAISAL framework (Martin 1997, 2000). APPRAISAL 1 systems are the semantic resources used to negotiate emotions, judgments, and valuations. In this article I will examine how choices from these systems vary in ways that are systematic — different history texts speak with different ‘voices’. These voices, I argue, are a key rhetorical strategy in history discourse. Different combinations of APPRAISAL resources are drawn on to negotiate the heteroglossic positions of their audiences. As such they are a key resource for both the professional and apprentice historian in their assessment of interpretations of the past

    Phenomenology of the Equivalence Principle with Light Scalars

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    Light scalar particles with couplings of sub-gravitational strength, which can generically be called 'dilatons', can produce violations of the equivalence principle. However, in order to understand experimental sensitivities one must know the coupling of these scalars to atomic systems. We report here on a study of the required couplings. We give a general Lagrangian with five independent dilaton parameters and calculate the "dilaton charge" of atomic systems for each of these. Two combinations are particularly important. One is due to the variations in the nuclear binding energy, with a sensitivity scaling with the atomic number as A−1/3A^{-1/3}. The other is due to electromagnetism. We compare limits on the dilaton parameters from existing experiments.Comment: 5 page

    Gaussian stationary processes over graphs, general frame and maximum likelihood identification

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    In this paper, using spectral theory of Hilbertian operators, we study ARMA Gaussian processes indexed by graphs. We extend Whittle maximum likelihood estimation of the parameters for the corresponding spectral density and show their asymptotic optimality

    Investigating Red Knot Migration Ecology along the Georgia and South Carolina Coasts: Spring 2019 Season Summaries

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    The rufa subspecies of the Red Knot (Calidris canutus) has declined significantly in the past 35 years, leading to federal listing (US Fish and Wildlife Service Federal Register Vol. 79 No. 238, 2014a) under the Endangered Species Act in the United States (16 U.S.C. 1531 et. seq) and Canada (COSEWIC 2007, SARA 2007). Evidence for the decline is seen in long-term surveys of a major spring staging site (Dunne et al 1982, Clark et al. 1993, Niles et al. 2008) and the largest known over-wintering site (Morrison et al. 2004). In only 30 years, the estimated population has declined from 100,000-150,000 to possibly below 30,000 (Niles et al. 2007) leading some researchers to suggest the population is highly vulnerable to extinction (Baker et al. 2004). The determination of regional population estimates and identification of major stopover sites are considered to be the highest priority for the Georgia Department of Natural Resources State Wildlife Action Plan (2015), the Atlantic Flyway Shorebird Business Strategy (Winn et al. 2013), the US Shorebird Plan (Brown et al. 2001), the USFWS Red Knot Spotlight Species Action Plan (2010), and the Western Hemisphere Shorebird Reserve Network (WHSRN) Red Knot Conservation Plan for the Western Hemisphere (Niles et al. 2010a). The Georgia Department of Natural Resources State Wildlife Action Plan ranks the Red Knot as a high priority species (with state status of “Rare”) and ranks research of the Red Knot as one of the primary conservation actions needed within the state. A band resight program was initiated along the Georgia coastal barrier islands during the fall of 2011 and spring of 2013 and 2015-2016 giving baseline information for those seasons (Lyons et al. 2017, Smith et al. 2017). A trapping and tagging project was initiated in South Carolina in recent years, though there has been no systematic resight effort within the state. The patterns observed in both studies suggest that Red Knots are using the south-Atlantic through Delaware Bay in spring as an open network of staging areas. Recent tagging results in South Carolina have documented direct spring flights from South Carolina to James Bay, suggesting that the south-Atlantic stopovers are more important in the life-cycle of shorebirds than is currently thought. It is currently unknown what percentage of Red Knots use the direct flight strategy vs. stopping in Delaware Bay on their northbound migration. Winter resighting work conducted in South Carolina suggests that virtually no Red Knots wintering along the south-Atlantic use Delaware Bay in spring migration. Although movement and settlement “decisions” are likely influenced by foraging conditions throughout the network, investigations into the factors driving movements during migration is necessary to better understand Red Knot migration ecology. This is critical in developing appropriate stopover models and adaptive management tools for land managers. The Georgia Department of Natural Resources, the South Carolina Department of Natural Resources, the US Fish and Wildlife Service, and The Center for Conservation Biology will initiate a Red Knot tagging and resighting program along the Atlantic Coast of Georgia during the spring of 2019 to be paired with the ongoing programs within Delaware Bay and elsewhere along the flyway. This project will provide critical data that will be used to analyze the ongoing questions regarding Red Knot habitat choice decision making in the south Atlantic Coast in spring. A large percentage (3-6%) of Red Knots have been previously captured and tagged with unique 2 to 3 digits alpha-numeric bands. This marked population allows for mark-resight studies of migratory populations of Red Knots with no capturing involved. A total of 27,356 Red Knots were detected during daily surveys in spring 2019 along the Georgia and South Carolina Coasts; of those, 4,917 were scanned for flags, and 315 individually banded Red Knots were resighted a total of 523 times from within the spring migrant population. A total of 71 marked to unmarked ratios were recorded during the field season, with an average of 3.6% of Red Knots individually marked over the course of the spring. The rough estimate for the total number of knots cycling through during the spring season is estimated superpopulation size for the spring 2019 season is 8,750 (3.6% of birds tagged and 315 individuals recorded). The Georgia Coast is a major stopover area annually for rufa Red Knots in spring migration and in certain years in fall migration. The superpopulation utilizing the coast in fall migration can exceed 23,000 birds (Lyons et al. 2017) and the rough estimate of spring migration superpopulation from this study is approximately 8,750 birds. The total estimated population of rufa Red Knots is 42,000 birds (Andres et al. 2012), suggesting that a high percentage of rufa knots are using the Georgia Coast in spring and in some years fall migration. There appears to be less variation in spring migration superpopulations between years than in fall migration, suggesting a more stable (but less abundant) food source for spring migrants

    A cryogenic liquid-mirror telescope on the moon to study the early universe

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    We have studied the feasibility and scientific potential of zenith observing liquid mirror telescopes having 20 to 100 m diameters located on the moon. They would carry out deep infrared surveys to study the distant universe and follow up discoveries made with the 6 m James Webb Space Telescope (JWST), with more detailed images and spectroscopic studies. They could detect objects 100 times fainter than JWST, observing the first, high-red shift stars in the early universe and their assembly into galaxies. We explored the scientific opportunities, key technologies and optimum location of such telescopes. We have demonstrated critical technologies. For example, the primary mirror would necessitate a high-reflectivity liquid that does not evaporate in the lunar vacuum and remains liquid at less than 100K: We have made a crucial demonstration by successfully coating an ionic liquid that has negligible vapor pressure. We also successfully experimented with a liquid mirror spinning on a superconducting bearing, as will be needed for the cryogenic, vacuum environment of the telescope. We have investigated issues related to lunar locations, concluding that locations within a few km of a pole are ideal for deep sky cover and long integration times. We have located ridges and crater rims within 0.5 degrees of the North Pole that are illuminated for at least some sun angles during lunar winter, providing power and temperature control. We also have identified potential problems, like lunar dust. Issues raised by our preliminary study demand additional in-depth analyses. These issues must be fully examined as part of a scientific debate we hope to start with the present article.Comment: 35 pages, 11 figures. To appear in Astrophysical Journal June 20 200

    USING 3D MODELS TO GENERATE LABELS FOR PANOPTIC SEGMENTATION OF INDUSTRIAL SCENES

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    Industrial companies often require complete inventories of their infrastructure. In many cases, a better inventory leads to a direct reduction of cost and uncertainty of engineering. While large scale panoramic surveys now allow these inventories to be performed remotely and reduce time on-site, the time and money required to visually segment the many types of components on thousands of high resolution panoramas can make the process infeasible. Recent studies have shown that deep learning techniques, namely deep neural networks, can accurately perform panoptic segmentation of things and stuff and hence be used to inventory the components of a picture. In order to train those deep architectures with specific industrial equipment, not available in public datasets, our approach uses an as-built 3D model of an industrial building to procedurally generate labels. Our results show that, despite the presence of errors during the generation of the dataset, our method is able to accurately perform panoptic segmentation on images of industrial scenes. In our testing, 80% of generated labels were correctly identified (non null intersection over union, i.e. true positive) by the panoptic segmentation, with great performance levels even for difficult classes, such as reflective heat insulators. We then visually investigated the 20% of true negative, and discovered that 80% were correctly segmented, but were counted as true negative because of errors in the dataset generation. Demonstrating this level of accuracy for panoptic segmentation on industrial panoramas for inventories also offers novel perspectives for 3D laser scan processing
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