113,120 research outputs found
Species- and Trait-Based Reconstructions of the Hydrological Regime in a Tropical Peatland (Central Sumatra, Indonesia) during the Holocene Using Testate Amoebae
No full textPaleoecological reconstructions of hydrological regimes in tropical peatlands during the Holocene are important for the estimation of their responses to changing environments. However, the application of some widely used proxies, such as testate amoebae, is hampered by poor knowledge of their morphology and ecological preferences in the region. The aim of this study is to describe the morphospecies composition of sub-fossil testate amoebae in deposits of a tropical peatland in Central Sumatra (Indonesia) during the Holocene and reconstruct the hydrological regime using morphospecies- and functional-trait-based approaches. In total, 48 testate amoeba morphospecies were observed. Based on morphospecies composition, we distinguished three main periods of peatland development (13,400–8000, 8000–2000, 2000 cal yr BP–present). The application of the morphospecies-based transfer function provided a more reliable reconstruction of the water regime in comparison to the functional trait-based one. The weak performance of the latter might be related to the poor preservation of shells and the greater variation in the functional traits in sub-fossil communities as compared to the training set and linear modeling approach. These results call for future studies on the functional and morphospecies composition of testate amoebae in a wider range of tropical peatlands to improve the quality of hydrological reconstructions
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Comparison of delta C-13 and delta D values of n-alkanes from angiosperms and gymnosperms in Western Europe
No full textComparison of delta C-13 and delta D values of n-alkanes from angiosperms and gymnosperms in Western Europe
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Orbital- and millennial-scale environmental changes between 64 and 20 ka BP recorded in Black Sea sediments
No full textHigh-resolution pollen and dinoflagellate cyst records from sediment core
M72/5-25-GC1 were used to reconstruct vegetation dynamics in northern
Anatolia and surface conditions of the Black Sea between 64 and 20 ka BP.
During this period, the dominance of Artemisia in the pollen record indicates a
steppe landscape and arid climate conditions. However, the concomitant
presence of temperate arboreal pollen suggests the existence of glacial
refugia in northern Anatolia. Long-term glacial vegetation dynamics reveal
two major arid phases ~64–55 and 40–32 ka BP, and two major
humid phases ~54–45 and 28–20 ka BP, correlating with higher
and lower summer insolation, respectively. Dansgaard–Oeschger (D–O) cycles
are clearly indicated by the 25-GC1 pollen record. Greenland interstadials
are characterized by a marked increase in temperate tree pollen, indicating
a spread of forests due to warm/wet conditions in northern Anatolia,
whereas Greenland stadials reveal cold and arid conditions as indicated by
spread of xerophytic biomes. There is evidence for a phase lag of
~500 to 1500 yr between initial warming and forest expansion,
possibly due to successive changes in atmospheric circulation in the North
Atlantic sector. The dominance of Pyxidinopsis psilata and
Spiniferites cruciformis in the dinocyst record indicates
brackish Black Sea conditions during the entire glacial period. The decrease
of marine indicators (marine dinocysts, acritarchs) at ~54 ka
BP and increase of freshwater algae (Pediastrum, Botryococcus) from 32 to 25 ka BP reveals
freshening of the Black Sea surface water. This freshening is possibly
related to humid phases in the region, to connection between Caspian Sea and
Black Sea, to seasonal freshening by floating ice, and/or to closer position
of river mouths due to low sea level. In the southern Black Sea, Greenland
interstadials are clearly indicated by high dinocyst concentrations and
calcium carbonate content, as a result of an increase in primary
productivity. Heinrich events show a similar impact on the environment in the
northern Anatolia/Black Sea region as Greenland stadials
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Stably stratified shear-produced turbulence and large-scalewaves in a lid driven cavity
No full textWe study experimentally stably stratified sheared turbulence and large-scale flows and waves in a lid driven cavity with a non-zero vertical mean temperature gradient. Geometrical properties of the large-scale vortex (e.g., its size and form) and the level of small-scale turbulence inside the vortex are controlled by the buoyancy (i.e., by the temperature stratification). The observed velocity fluctuations are produced by the shear of the large-scale vortex. At larger stratification obtained in our experiments, the strong turbulence region is located at the upper part of the cavity where the large scale vortex exists. In this region the Brunt-Väisälä frequency is small and increases in the direction outside the large-scale vortex. This is the reason of that the large-scale internal gravity waves are observed in the regions outside the large-scale vortex. We found these waves by analyzing the non instantaneous correlation functions of the temperature and velocity fields. The observed large-scale waves are nonlinear because the frequency of the waves determined from the temperature field measurements is two times smaller than that obtained from the velocity field measurements. The measured intensity of the waves is of the order of the level of the temperature turbulent fluctuations
Tropical rain-forest history from the Colombian Pacific area: a 4200-year pollen record from Laguna Jotaordó
No full textPollen analysis of a 5 m long core from Lake Jotaordó, located in northern ‘Chocó biogeographic area’ (5°48[.minute] N, 76°42[.minute] W) along the Pacific coast of Colombia, shows the environmental history of the rain forest during the last 4200 years. Time control has been based on 6 AMS 14 C dates ranging from 4230 to 365 14 C yr BP. The period of 4230 to 4053 14C yr BP shows sandy deposits and river influence and represents at that time the initial phase of the lake. The composition of the rain forest was different compared to the last 1400 years. Pioneer taxa belonging to Cecropia, Melastomataceae/Combretaceae and Moraceae/Urticaceae dominated the forest. A 30 cm thick organic rich clay from 440 to 410 cm core depth spans a period of 2600 years (from 4050 to 1450 14 C yr BP), pointing to a hiatus in the sediment record, possibly caused by riverine erosion of previously deposited sediments. During the last 1400 years rain forest is characterized by Mauritiella, Euterpe/Geonoma, Iriartea, Pachira aquatica and Malpighiaceae. Floral composition of the rain forest is not constant. Abiotic dynamics caused changes in the drainage system. The presence of human settlements during the last 1000 yrs is evidenced by Zea mays and possibly also by the increase of palms
Ratio of n-6/n-3 in the diets of beef cattle
No full textEffects of feeding heat-treated canola (C), soybean (S) and flax (F) or mixtures on growth and slaughter characteristics, taste and fatty acid (FA) composition of beef tissue were investigated using 128 crossbred steers to determine the potential of improving the nutritional quality of beef for humans. For Trial 1 (48 steers), dietary treatments were: roasted C, extruded C, roasted S, extruded S, roasted F and extruded F. For Trial 2 (80 steers), the dietary treatments were: S:F (1:1), S:C (1:1), C:F (1:1) and S:F:C (1:1:1), and the oilseeds were processed either by roasting or extruding before mixing. Soybean meal and soybean oil were used to give equivalent lipid and protein contents to each experimental diet. The basal diet consisted of grass silage, barley grain, vitamins and minerals. Steers were fed for a minimum of 100d then slaughtered at a uniform degree of finish. Growth and slaughter characteristics of the steers were only slightly affected by dietary treatment in that the soybean-fed steers consumed more feed and had a higher average daily gain than the canola or flax-fed animals in Trial 1. There was no difference in taste panel parameters for any of the treatments. Inclusion of flax in the diet increased the total n-3 content of meat. Similar results were found for canola and C18:1n-9 although this was not the case for soybean and the n-6 FA. For the n-6 FA in the PL and neutral lipid fractions of the meat samples, levels were correlated with high dietary levels of n-6 or n-9 with low levels of n-3 while for the n-3 FA, levels were correlated with high dietary n-3 levels and low n-6 levels. Oilseed processing method did not have an effect on any fatty acid levels. It is possible to modify the FA composition of beef meat toward a healthier profile by including heat-treated oilseeds in the diet to influence the degree of lipid metabolism in the rumen.ID: S0377840111004007; M3: Article; Accession Number: S0377840111004007; Author: M.A. McNiven (a, ⁎); Author: J.L. Duynisveld (b); Author: T. Turner (a); Author: A.W. Mitchell (a); Affiliation: Department of Health Management, Atlantic Veterinary College, University of PEI, Charlottetown, PEI, Canada C1A 4P3; Affiliation: Agriculture and Agri-Food Canada, Nappan, NS, Canada B0L 1C0; Keyword: Oilseeds; Keyword: Roasted; Keyword: Extruded; Keyword: Fatty acids; Keyword: Healthy fat; Number of Pages: 11; Language: English
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