37,200 research outputs found
C-14 and Be-10 in dust deposited during the storm of 16-17 April 2006 in Beijing
No full textThe concentrations of Be-10 and C-14 and values of delta C-13 in samples collected during a major dust storm in Beijing on 16-17 April 2006 were studied. The Be-10 concentrations ranged from 1.69 x 10(8) to 2.07 x 10(8) atom/g, C-14 ages for black carbon (BC) ranged from 3001 to 5181 yr BP and for total inorganic carbon (TIC) from 8464 to 9119 yr BP, and delta C-13 values for BC ranged from -23.15% to -23.80% and for TIC from -5.39% to -5.98%. A comparison of BC content and delta C-13 value between the dust, surface soil in the dust source region, and aerosols in Beijing indicated that BC in the dust deposited in Beijing is significantly incorporated by aerosol BC during the dust transportation. Based on the C-14 ages of BC, the proportion of fossil-fuel-derived BC was 0.35-0.49 of the total. In contrast to BC, the TIC deposited in Beijing can be firmly related to the source area and delta C-13 was not significantly modified during its transportation. According to the C-14 ages of TIC, the proportion of the secondary carbonate in the dust was from 0.63 to 0.70. The results confirm that C-14 of TIC is another useful tracer to indicate the source region of dust besides the content and delta C-13 value of TIC from the arid and semi-arid regions of China.Geochemistry & GeophysicsSCI(E)0ARTICLE2-31790-18005
Observation of Ξ c(2930) 0 and updated measurement of B-→K-Λc+Λ ̄c- at Belle: Belle Collaboration
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Justification of the MHD energy principle for the stability of a confined toroidal plasma
No full textA homolog of Ste6, the a-factor transporter in Saccharomyces cerevisiae, is required for mating but not for monokaryotic fruiting in Cryptococcus neoformans
No full textAmynthas quadriorbis Shen and Chang
No full textAmynthas quadriorbis Shen and Chang, sp. nov. (Figure 2) Type material Holotype. Clitellate (107 mm in length, dissected) collected 17 July 2007 from roadside slope along Waihu Creek (elevation 230 m) near the borders of Douliou and Linnei, Yunlin by C.H. Chang, T.J. Lin and Y.H. Lin (TESRI-O-H- 47) (voucher number: WH 3 P 1). Paratype. One clitellate collected 15 August 2007 from type locality by C.H. Chang, Y.H. Lin and Y.P. Li (TESRI-O-P- 42). Diagnosis Medium earthworm; length (clitellates) 107 – 120 mm. Segments numbering 103 – 129. Setae 60 – 68 in VII, 73 – 76 in XX and 15 – 18 between male pores. Clitellum XIV – XVI. First dorsal pore in 11 / 12. Spermathecal pores invisible or small, three pairs in 6 / 7 – 8 / 9, 0.29 – 0.30 body circumference ventrally apart. Genital papillae absent in preclitellar region. Male pores 0.24 body circumference ventrally apart in XVIII, each on a round porophore surrounded by two to four circular or diamond-shaped shallow skin folds. Two large genital papillae medial to each male porophore: one immediately adjacent to intersegmental furrow of 17 / 18 and the other to 18 / 19. Spermathecae small, three pairs in VII – IX. Seminal vesicles small, two pairs in XI and XII, occupying two-thirds of segmental compartment, each vesicle with a prominent, round or oval dorsal lobe. Prostate glands small in XVII – XVIII. Prostatic duct stout, C-shaped. Accessory glands absent. Description External characters. Total length (clitellates) 107 – 120 mm. Weight 1.19 – 1.54 g. Segments numbering 103 – 129. Clitellum XIV – XVI, setae and dorsal pores absent, length 3.65 – 4.59 mm and width 3.83 – 4.21 mm. Prostomium epilobous. Setae minute, numbering 60 – 68 in VII, 73 – 76 in XX and 15 – 18 between male pores in XVIII. First dorsal pore in 11 / 12. Spermathecal pores invisible or small, three pairs in intersegmental furrows of 6 / 7 – 8 / 9; distance between paired pores 0.29 – 0.30 body circumference ventrally apart. Genital papillae absent in the preclitellar region. Female pore single, mid-ventral in XIV. Male pores paired in XVIII, about 0.24 body circumference ventrally apart, each on a round porophore surrounded by two to four circular or diamond-shaped shallow skin folds. Two large genital papillae medial to each male porophore: one presetal and the other postsetal with the former immediately adjacent to intersegmental furrow of 17 / 18 and the latter to 18 / 19, both confined in segment XVIII, 0.45 – 0.60 mm in diameter with depressed centre (Figure 2 a). Preserved specimens brown on dorsum, brown to greyish brown on clitellum, and greyish on ventrum. Internal characters. Septa 5 / 6 – 7 / 8 thick, 10 / 11 – 13 / 14 muscular, 8 / 9 / 10 absent. Nephridial tufts on anterior faces of 5 / 6 / 7. Gizzard large in VIII – X. Intestine enlarged from XVI. Intestinal caeca paired in XXVII, extending anteriorly to XXII, each long, simple, stout, slightly bent. Oesophageal hearts in XI – XIII. Spermathecae small, three pairs in VII – IX (sexthecate) (Figure 2 b). Each ampulla pearshaped or elongated oval-shaped, 0.56 – 1.03 mm long and 0.40 – 0.70 mm wide, with a slender or stout spermathecal stalk 0.35 – 0.58 mm in length. Diverticulum with an iridescent, oval-shaped seminal chamber of 0.25 – 0.50 mm long and a slender stalk of 0.60 – 0.68 mm in length. Accessory glands absent in the preclitellar region. Holandry: testes small, oval, two pairs in ventrally joined sacs in X and XI. Seminal vesicles small, transversely elongated, two pairs in XI and XII, occupying two-thirds of segmental compartment, each vesicle with a prominent, round or oval dorsal lobe. Prostate glands small in XVII – XVIII, smooth, lobed, flower-like. Prostatic duct stout, C-shaped (Figure 2 c). Accessory glands absent. DNA barcode GenBank accession number KU 232820 (WH 3 P 1, holotype). Etymology The name quadriorbis refers to the four large genital papillae in the male pore region. Remarks Amynthas quadriorbis sp. nov. is only known from its type locality in the foothills at elevations <250 m near Douliou, Yunlin, southwestern Taiwan. According to Tsai et al. (2004), the number of native earthworm species decreased while the number of exotic species increased with decreasing elevation, and this species shift is primarily attributable to habitat replacement due to human disturbance. Nowadays only seven native species, Metaphire formosae (Michaelsen, 1922), Amynthas swanus (Tsai 1964), Amynthas binoculatus Tsai, Shen and Tsai, 1999, Amynthas sexpectatus Tsai, Shen and Tsai, 1999, Amynthas tungpuensis Tsai, Shen and Tsai, 1999, Metaphire bununa Tsai, Tsai and Liaw, 2000 and Amynthas penpuensis Shen, Tsai and Tsai, 2003, were found at elevations below 500 m in centro-western Taiwan with A. swanus being the rarest (Tsai et al. 2004 and unpublished data, H.-P. Shen). The fact that A. quadriorbis has only been found in one location throughout the extensive surveys conducted in the region in the last decade suggests that A. quadriorbis is also rare. With their habitat subjected to intensive agricultural activities, both A. swanus and A. quadriorbis may be considered as an endangered species. Amynthas quadriorbis has three pairs of spermathecal pores in intersegmental furrows of 6 / 7 – 8 / 9, and so belongs to the holandric, sexthecate sieboldi species-group of the genus Amynthas (Sims and Easton 1972). Among the members of the sieboldi -group, the peregrine Amynthas hupeiensis (Michaelsen, 1895) from China and Amynthas obscurus (Goto and Hatai, 1898) from Japan have a genital papilla arrangement in the male pore area similar to A. quadriorbis. However, A. hupeiensis has paired genital papillae in the intersegmental furrows of 17 / 18 and 18 / 19 (Chen 1933; Tsai 1964), much higher setal number than A. quadriorbis with 100 – 121 in VIII and 79 – 88 in XX (Tsai 1964) and very long diverticula (Chen 1933; Tsai 1964). Amynthas obscurus is smaller (80 mm long with 76 segments), has an additional pair of papillae in postsetal XIX, and has much lower setal number with 35 – 38 in the spermathecal segments (Goto and Hatai 1898). The arrangement of genital papillae in the male pore area of A. quadriorbis is also similar to that of Amynthas modiglianii (Rosa 1889) from Nias, Indonesia, Amynthas micronarius (Goto and Hatai, 1898) from Japan, and Amynthas tetrapapillatus Quan and Zhong, 1989 from Hainan Island, China. Amynthas modiglianii is an octothecate earthworm with four pairs of spermathecal pores in intersegmental furrows of 5 / 6 – 8 / 9 and has coiled diverticula (Rosa 1889; Michaelsen 1934). Amynthas micronarius is also octothecate without diverticula or with minute diverticula, and has much lower setal number than A. quadriorbis with 26 – 39 in VII and 33 – 51 in XX (Ohfuchi 1937) and welldeveloped prostate glands (Goto and Hatai 1898; Ohfuchi 1937). As for A. tetrapapillatus, it has paired genital papillae in the intersegmental furrows of 17 / 18 and 18 / 19, a pair of spermathecal pores on the dorsal side of the intersegmental furrow of 5 / 6, and much higher setal number than A. quadriorbis with 93 – 107 in VII and 86 – 102 in XX (Quan and Zhong 1989).Published as part of Shen, Huei-Ping, Chang, Chih-Han & Chih, Wen-Jay, 2016, Four new earthworm species of the genus Amynthas (Megascolecidae: Oligochaeta) from southwestern Taiwan with re-description of Amynthas tungpuensis Tsai, Shen and Tsai, 1999, pp. 1889-1910 in Journal of Natural History 50 (29 - 30) on pages 3-7, DOI: 10.1080/00222933.2016.1180721, http://zenodo.org/record/26905
Revisiting revisitation in computer interaction: organic bookmark management
No full textAccording to Milic-Frayling et al. (2004), there are two general ways of user browsing i.e. search (finding a website where the user has never visited before) and revisitation (returning to a website where the user has visited in the past). The issue of search is relevant to search engine technology, whilst revisitation concerns web usage and browser history mechanisms. The support for revisitation is normally through a set of functional built-in icons e.g. History, Back, Forward and Bookmarks. Nevertheless, for returning web users, they normally find it is easier and faster to re-launch an online search again, rather than spending time to find a particular web site from their personal bookmark and history records. Tauscher and Greenberg (1997) showed that revisiting web pages forms up to 58% of the recurrence rate of web browsing. Cockburn and McKenzie (2001) also stated that 81% of web pages have been previously visited by the user. According to Obendorf et al. (2007), revisitation can be divided into four classifications based on time: short-term (72.6% revisits within an hour), medium-term (12% revisits within a day and 7.8% revisits within a week), and long-term (7.6% revisits longer than a week
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