49,267 research outputs found
Hamblin Robert L., Jacobsen R. Brooke, Miller Jerry L.L — A mathematical theory of social change
No full textD. F. Hamblin Robert L., Jacobsen R. Brooke, Miller Jerry L.L — A mathematical theory of social change. In: Population, 30ᵉ année, n°1, 1975. p. 181
Studier Tilegnede Professor Dr. Phil, et Theol. Frants Buhl, Redigeret af J. Jacobsen, 1925
No full textR. C. Studier Tilegnede Professor Dr. Phil, et Theol. Frants Buhl, Redigeret af J. Jacobsen, 1925. In: Revue d'histoire et de philosophie religieuses, 7e année n°1, Janvier-février 1927. p. 90
Studier Tilegnede Professor Dr. Phil, et Theol. Frants Buhl, Redigeret af J. Jacobsen, 1925
No full textR. C. Studier Tilegnede Professor Dr. Phil, et Theol. Frants Buhl, Redigeret af J. Jacobsen, 1925. In: Revue d'histoire et de philosophie religieuses, 7e année n°1, Janvier-février 1927. p. 90
Afroedura leoloensis Jacobsen, Kuhn, Jackman & Bauer, 2014, sp. nov.
No full textAfroedura leoloensis sp. nov. (Fig. 10 B) Afroedura pondolia langi (part) Visser 1984 a (fig. p. 61) Afroedura langi 'Leolo' Jacobsen 1992 a, 1997 Holotype. TM 81113, adult male, Farm Hendriksplaats 281 KT, 24 ° 38 ' S, 30 °08' E, Lydenburg District, (2430 CA) Mpumalanga Province, Republic of South Africa, collectors R. E. Newbery and W. Petersen, 15 November 1985. Paratypes. TM 81115, TM 81125, 81127, same data as for holotype; TM 81119, 81124, Farm Maandagshoek 254 KT, Sekhukhuneland District, Limpopo Province (2430 CA) collector N. H. G. Jacobsen, 25 October 1980; TM 81112, 81116– 81118, same locality as TM 81119, collector R.E.Newbery, 29 June 1982; TM 81126, Farm Kalkfontein 367 KT, Lydenburg District, Mpumalanga Provicne (2430 CC), collector N. H. G. Jacobsen, 23 April 1981; TM 81114, 81121, 81123, 81128, same locality as TM 81126, collectors R. E. Newbery and W. Petersen, 16 November 1985; TM 81122, Kgoloko lokasie, Sekhukhuneland District, Limpopo Province (2429 DB), collector R. E. Newbery, 27 October 1980; TM 81120, Farm De Grooteboom 373 KT, Lydenburg District, Mpumalanga Province (2430 CC), collector N. H. G. Jacobsen, 23 October 1981. Etymology. The specific epithet refers to the Leolo hills in Sekhukhuneland, Limpopo Province, where it was first discovered. Diagnosis. A small Afroedura (maximum SVL 40.5 mm) differing from all other congeners by the following combination of characters: two pairs of enlarged subdigital lamellae per digit; tail faintly verticillate and flattened near base, with four subcaudal rows and 6–7 supracaudal rows per verticil; dorsal scales smooth, 87–95 scale rows at midbody; internasal scales typically absent; 31–35 precloacal pores in males. Description. (based on holotype TM 81113) Adult male; 37.0 mm SVL; 45.0 mm TailL; mass before preservation 0.9 g. Body small and slender, dorsoventrally depressed; head oval, wider than the neck. Rostral approximately 2.5 times wider than high; nostril pierced between rostral, first upper labial and three nasal scales; nasorostrals in moderate contact behind rostral. Scales on snout hexagonal, flattened and much larger than scales on crown of head; nine scales between nasals and eye and 16 scales between eye and ear. Four supraciliary spines. Supralabials 10. Mental wedge-shaped, much longer than wide and in contact with two postmentals. Infralabials eight. Dorsal scales minute, more-or-less homogeneous, smooth, juxtaposed to subimbricate, rounded to slightly hexagonal. Midbody scales 89. Ventrals large, smooth and imbricate. Digits with two pairs of enlarged scansors and six enlarged inferomedian scales under the fourth toe. Precloacal pores in a continuous, almost straight row of 34. Tail broad and flattened near the base, tapering to a fine tip, faintly verticillate; caudal scales arranged in six dorsal and four ventral rows per verticil. Supracaudals subimbricate, almost rectangular; subcaudals as broad as long and imbricate. Two postcloacal spurs on either side of tail base. Color. Pale brown to brown dorsally with 7–8 dark brown irregular crossbands extending from the occiput to sacrum. Crossbands with darker posterior margins and, in most specimens, a white vertebral spot just posterior to each crossband. Limbs longitudinally striped or banded. The paler areas between the stripes are spotted dark brown. Crown of head pale brown with darker spotting and other variegations. Tail with 10 blackish crossbands from base to tip. Venter pinkish; tail brownish with darker markings. Variation. Paratypes and other specimens agree with the holotype in most features of scalation (Table 4). Nasorostrals in broad contact behind rostral but separated posteriorly by a single granule in TM 81120. Scales between nasals and eye 9–12, from eye to ear 16–18. Five supraciliary spines in TM 81115. Mental as long as broad in some specimens; postmentals three in TM 811141. Supralabials 8–10. Infralabials 6–10. Midbody scale rows 87–95. 0–8 enlarged inferomedian scales under fourth toe. Precloacal pores in male paratypes 31–35 (except for TM 81126, which has only 11), females lacking pores. Original tails 50.00– 55.9 % of total length. Supracaudal scales in 6 or 7 rows per tail whorl. Tail has been autotomized in 54.5 % of the specimens examined (n= 17). Distribution. Endemic to the Leolo Hills and outcrops above the Steelpoort River on either side of the border between Mpumalanga and Limpopo Provinces (Fig. 6). Natural history. Exclusively rupicolous, apparently limited to norite and granitic formations. Afroedura leoloensis sp. nov. lives in narrow crevices under exfoliating rock. These are usually on the underside of boulders with the openings facing downwards, protecting them from rain. The species is found in Sekhukhune Mountain Bushveld (SVcb 28) and Leolo Summit Sourveld (GM 20) (Mucina & Rutherford 2006) at an elevation of 1200–1800 m a.s.l. Two eggs are laid at a time and measure 8.9 –9.0 x 6.1–6.4 mm with a mass of 0.2 g. The eggs appear to be laid in midsummer and are initially soft-shelled, adhering to the rock and then hardening. Remarks. Afroedura leoloensis sp. nov. is a member of the A. langi clade (Figs. 1–2; see Remarks under A. granitica sp. nov.). This species exhibits the highest number of precloacal pores (31–35) not only in its clade, but in the genus as a whole, and may thus be distinguished from its congeners.Published as part of Jacobsen, Niels H. G., Kuhn, Arianna L., Jackman, Todd R. & Bauer, Aaron M., 2014, A phylogenetic analysis of the southern African gecko genus Afroedura Loveridge (Squamata: Gekkonidae), with the description of nine new species from Limpopo and Mpumalanga provinces of South Africa, pp. 451-501 in Zootaxa 3846 (4) on pages 486-487, DOI: 10.11646/zootaxa.3846.4.1, http://zenodo.org/record/25049
Cisgenesis: an important sub-invention for traditional plant breeding companies
No full textModern plant breeding is highly dependent on new technologies to master future problems. More traits have to be combined, frequently originating from wild species. Traditional breeding is connected with linkage drag problems. The crop plant itself and its crossable species represent the traditional breeders gene pool. GM-breeding is a new way of improving existing varieties. Transgenes originate from non-crossable species and are representing a new gene pool. For release of GM-plants into the environment and onto the market in Europe Directive 2001/18/EC has been developed, primarily based on GM-technology and not on gene source. In society, opposition against GM crops is complicating the implementation of GM crops. In this paper, it is shown that not only transgenes, representing a new gene pool but also cisgenes and intragenes are available, representing the breeders gene pool. Cisgenes are natural genes and intragenes are composed of functional parts of natural genes from the crop plant itself or from crossable species. Cisgenesis is the combined use of only cisgenes with marker-free transformation, mimicking linkage drag free introgression breeding in one step. Therefore, cisgenesis is a new sub-invention in the traditional breeding field and indicates the need for reconsideration of GM Directives. Inventions are frequently containing not only hardware elements, but also software and orgware elements. For cisgenesis it is foreseen that the technical (hardware) and bioinformatic (software) elements will develop smoothly, but that implementation in society is highly dependent on acceptance and regulations (orgware). It could be made in a step by step approach by specific crop-gene derogations from the Directive, followed by adding cisgenesis to annex 1b of Directive 2001/18/EC for exemption. At present GM crops can only be introduced by large companies. An open innovation approach for cisgenesis by public private partnership including traditional SMEs has been discussed. Cisgenesis has been exemplified for resistance breeding of potato to Phytophthtora infestans
Laguerre geometry of hypersurfaces in R-n
No full textLaguerre geometry of surfaces in R-3 is given in the book of Blaschke [Vorlesungen uber Differentialgeometrie, Springer, Berlin Heidelberg New York (1929)], and has been studied by Musso and Nicolodi [Trans. Am. Math. soc. 348, 4321-4337 (1996); Abh. Math. Sem. Univ. Hamburg 69, 123-138 (1999); Int. J. Math. 11(7), 911-924 (2000)], Palmer [Remarks on a variation problem in Laguerre geometry. Rendiconti di Mathematica, Serie VII, Roma, vol. 19, pp. 281-293 (1999)] and other authors. In this paper we study Laguerre differential geometry of hypersurfaces in R-n. For any umbilical free hypersurface x:M -> R-n with non-zero principal curvatures we define a Laguerre invariant metric g on M and a Laguerre invariant self-adjoint operator S:TM -> TM, and show that {g,S} is a complete Laguerre invariant system for hypersurfaces in R-n with >= 4. We calculate the Euler-Lagrange equation for the Laguerre volume functional of Laguerre metric by using Laguerre invariants. Using the Euclidean space R-n, the semi-Euclidean space R-1(n) and the degenerate space R-0(n) we define three Laguerre space forms URn, UR1n and UR0n and define the Laguerre embeddings URn1 -> URn and UR0n -> URn, analogously to what happens in the Moebius geometry where we have Moebius space forms S-n, H-n and R-n (spaces of constant curvature) and conformal embeddings H-n -> S-n and R-n -> S-n[cf. Liu et al. in Tohoku Math. J. 53, 553-569 (2001) and Wang in Manuscr. Math. 96, 517-534 (1998)]. Using these Laguerre embeddings we can unify the Laguerre geometry of hypersurfaces in R-n, R-1(n) and R-0(n). As an example we show that minimal surfaces in R-1(3) or R-0(3) are Laguerre minimal in R-3.MathematicsSCI(E)0ARTICLE173-9512
Afroedura waterbergensis Jacobsen, Kuhn, Jackman & Bauer, 2014, sp. nov.
No full textAfroedura waterbergensis sp. nov. (Fig. 11 A) Afroedura langi 'Waterberg' Jacobsen 1990, 1992a, 1997 Holotype. TM 81266, adult female, Farm Waterval 601 LQ, 23 ° 53 ' S, 27 ° 39 ' E, Waterberg District (2327 DC), Limpopo Province, collectors N. H. G. Jacobsen & R. E. Newbery, 20 January 1987. Paratypes. TM 81267, 81269, 81273, Farm Fancy 556 LQ, Waterberg District, Limpopo Province (2327 DC), collectors N. H. G. Jacobsen & R. E. Newbery, 22 January 1987. TM 81268, 81270, Farm Fourieskloof 557 LQ, Waterberg District, Limpopo Province (2327 DC), collector R. E. Newbery, 26 September 1979; TM 81271–81272, same data as for holotype. Etymology. The specific epithet refers to the Waterberg massif, Limpopo Province, to which the species is endemic. Diagnosis. A small Afroedura (maximum SVL 46 mm) differing from all other congeners by the following combination of characters: two pairs of enlarged subdigital lamellae per digit; tail moderately verticillate (semiverticillate) and flattened near base, with four subcaudal rows and 7 supracaudal rows per verticil; dorsal scales smooth, 92–99 scale rows at midbody; internasal scales absent; 4–7 precloacal pores in males. Description. (based on holotype TM 81266) Adult female, SVL 44.0 mm; TailL 53.0 mm; mass before preservation 2.2 g. A small to medium-sized, dorsoventrally depressed gecko. Head oval, neck thick, almost as wide as head. Rostral approximately 2.5 times wider than high; nostril pierced between rostral, first supralabial and three nasals; nasorostrals large and in contact behind rostral. Scales on snout rounded but not flattened, decreasing in size posteriorly to crown of head; 9–10 granular scales between nasals and eye and 18 from eye to ear; 3–4 supraciliary spines; supralabials 11. Mental longer than broad and not wedge-shaped; postmentals two; infralabials nine. Dorsal scales smooth, juxtaposed, uniform and rounded, becoming larger and oblique laterally. Midbody scales in 101 rows. Ventral scales hexagonal to rounded, smooth and juxtaposed. Hindlimbs robust, feet moderately enlarged. Digits with two pairs of enlarged scansors and 4 th toe with six enlarged inferomedian scales. Precloacal pores absent. Tail semi-verticillate, flattened and tapered, constricted at base and widening at the beginning of the first verticil. Caudal scales arranged in verticils with seven dorsal and four ventral rows. Supracaudals subimbricate, more or less square with a rounded posterior margin; subcaudals imbricate wider than or as wide as long. Two postcloacal spurs on either side of tail base. Color. Brown to pale brown above with 6–7 wavy dark brown to blackish crossbands extending from the occiput to the sacrum. Posterior margin of crossbands darker and with white spots in indentations. A vertebral row of white spots is most pronounced. Crown of head marbled with dark brown and a dark brown stripe extending from the nostril through the eye, merging into the occipital crossbar. Limbs striped with dark brown, with interstices spotted and a reticulate pattern on the thighs. Venter white to whitish pink. Tail with seven crossbands at regular intervals. Underside of tail brown with incomplete pale crossbars. Variation. Paratypes and other specimens agree with the holotype in most features of scalation (Table 4). Scales from eye to ear 16–18. Mental in some specimens only as long as wide. Supralabials 8–11. Infralabials 7–9. Midbody scale rows 92–99. Eight enlarged inferomedian scales under 4 th toe in TM 81272. Precloacal pores in males in continuous series of 4–7. 0–3 postcloacal spurs on either side of tail base. Original tails 50.0– 56.4 % of total length. Supracaudal scales in 6–7 (rarely 8) rows per tail whorl. 33 % of specimens have regenerated tails (n= 6). Distribution. Endemic to the western Waterberg massif, Limpopo Province (Fig. 6). Natural history. Afroedura waterbergensis sp. nov. is a rupicolous gecko found in crevices between rocks on rocky outcrops and cliff faces of Waterberg sandstone. It inhabits both vertical and horizontal dry crevices. It has only been observed in Waterberg Mountain Bushveld (SVcb 17) (Mucina & Rutherford 2006) at an elevation of 1000 m a.s.l. Remarks. Afroedura waterbergensis sp. nov. is the westernmost member of its genus in Limpopo Province. It may be more widespread along the Waterberg than the current records indicate. It is a member of the A. langi complex and may be easily distinguished from all other members of this clade on the basis of its low number of precloacal pores (see Table 4).Published as part of Jacobsen, Niels H. G., Kuhn, Arianna L., Jackman, Todd R. & Bauer, Aaron M., 2014, A phylogenetic analysis of the southern African gecko genus Afroedura Loveridge (Squamata: Gekkonidae), with the description of nine new species from Limpopo and Mpumalanga provinces of South Africa, pp. 451-501 in Zootaxa 3846 (4) on pages 488-490, DOI: 10.11646/zootaxa.3846.4.1, http://zenodo.org/record/25049
Selective amplification of frequency comb modes via optical injection locking of a semiconductor laser: influence of adjacent unlocked comb modes
No full textOptical injection locking can be used to isolate and amplify individual comb modes from an optical frequency comb (OFC). However, it has been observed that for narrow spaced OFCs (e.g. 250 MHz), the adjacent comb modes are still present in the output of the locked laser. These residual modes experience some amplification relative to the injected signal, however the gain is significantly less than for the locked mode. We report the measurement of this sidemode amplification for a semiconductor laser injection locked to a 250 MHz spaced OFC. It was found that this amplification can be well suppressed by tuning the frequency difference between the free running laser and the OFC mode it was locked to. The sidemode amplification was then investigated numerically by solving the laser rate equations under optical injection. It was found that the main contribution to the sidemode amplification was due to phase modulation induced by the residual comb modes. The detuning dependent suppression occurs due to destructive interference between pairs of equidistant comb modes
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
57. The Oxyrhynchus Papyri, vol. XLIX. Edited with translations and notes by A. Bulow-Jacobsen, J. E. G. Whitehorne, with contributions of R. Hübner, J. C. Shelton, S. A. Stephens, J. Bingen, D. Foraboschi, S. S. Foulk, P. J. Parsons, J. R. Rea, R. D. Sullivan and members of the Istituto Papirologico G. Vitelli, Florence (Graeco-Roman Memoirs, n° 69)
No full textIrigoin Jean. 57. The Oxyrhynchus Papyri, vol. XLIX. Edited with translations and notes by A. Bulow-Jacobsen, J. E. G. Whitehorne, with contributions of R. Hübner, J. C. Shelton, S. A. Stephens, J. Bingen, D. Foraboschi, S. S. Foulk, P. J. Parsons, J. R. Rea, R. D. Sullivan and members of the Istituto Papirologico G. Vitelli, Florence (Graeco-Roman Memoirs, n° 69). In: Revue des Études Grecques, tome 96, fascicule 455-459, Janvier-décembre 1983. pp. 346-347
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