49,624 research outputs found
The effect of slug grazing on vegetation development and plant species diversity in an experimental grassland
No full text1. Generalist herbivores such as slugs have the potential not only to reduce plant density and biomass, but also to alter species diversity within vegetation. Their impact on species diversity may be either negative, if they concentrate feeding on less abundant plant species, or positive, if they feed on the most abundant species. 2. This study investigated the influence of slugs on plant species diversity in experimental swards produced by sowing a Lolium perenne/Trifolium repens seed mixture in field plots with a large seed bank of mainly arable species. Half of the plots were grazed by Arion lusitanicus Mabille. Plant cover, above-ground biomass and number of plant species were measured over a 3-year period. 3. Vegetation cover increased in the control plots from 50% in the first year to 90% in the third year. Cover was significantly lower in the slug plots in the first year (> 22%), while there were only small differences between treatments in the third year. Slugs reduced total above-ground biomass by > 25% in both the first and third years. 4. Slugs had a negative impact on plant species diversity in the first year, particularly by reducing forb species. In contrast, plant species diversity after 3 years was higher in the slug plots than in the controls, because of the higher number of forb species. Under slug grazing, the biomass and cover of annual and palatable species were reduced, but not the numbers of these species. 5. Our results suggest that slugs can have a significant effect on plant species diversity in plant communities, but that the direction of the effect changes during the course of succession. In the earliest stages, when most species are present as seedlings or juveniles, slug grazing leads to reduced species diversity because favoured species are eliminated. In closed vegetation, in which competitive interactions are important, slugs may reduce the dominance of the more competitive species and thus provide gaps in which plants can establish from seed. As a consequence, slugs tend to cause an increase in plant species diversity, and may also reduce the rate of successional change by promoting the persistence of annual species
LEGO® trifft auf Genregulation bei Prokaryoten am Beispiel des lac- und trp-Operons. Entwickelung eines Funktionsmodells zur Erarbeitung der Genregulation bei Eukaryoten am Beispiel des lac- und trp-Operons
No full textSchmiedebach M, Blümel H, Buschmann J-K, Wegner C. LEGO® trifft auf Genregulation bei Prokaryoten am Beispiel des lac- und trp-Operons. Entwickelung eines Funktionsmodells zur Erarbeitung der Genregulation bei Eukaryoten am Beispiel des lac- und trp-Operons. MNU Journal. Accepted
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Mesophilic-hydrothermal-thermophilic (M-H-T) digestion of green corn straw
No full textMesophilic-hydrothermal (80-160 degrees C, 30 min)-thermophilic (M-H-T) digestion and control tests of mesophilic (M), thermophilic (T), hydrothermal-mesophilic (H-M), and mesophilic-thermophilic digestion (M-T) of green corn straw were conducted for a 20-day fermentation period. The results indicate that M-H-T is an efficient method to improve methane production. A maximum methane yield of 371.74 mL/g volatile solid was obtained by the M (3 days)-H (140 degrees C)-T (17 days) process, which was 20.44%, 16.55%, 31.44%, and 14.31% higher than the yields of the M, T, 140-M, and M-T processes. The enhanced methane production was attributed to (1) the improved hemicellulose degradation and lignin disorganization; (2) prevention of the degradation of soluble sugar, easily hydrolyzed hemicellulose and cellulose into furfural and methylfurfural; and (3) lack of formation of Maillard reaction products during initial hydrothermal treatment. (C) 2015 Elsevier Ltd. All rights reserved
Thylakogaster namibiensis Brenke & Buschmann, 2009, sp. nov.
No full text<i>Thylakogaster namibiensis</i> sp. nov. (Figs. 1–5) <p> <i>Material:</i> 14 specimens of <i>Thylakogaster namibiensis</i> sp. nov. were found at four stations during the Diva 1 expedition (Tab. 1).</p> <p> <i>Holotype:</i> ♂, 1.9 mm, Area 4, Station #340 (EBS 09): 18°18.3’S 004°41.3’E to 18°19.4’S 004°41.9’E, 5395 m depth; ZMH K-40840 A–N, 14 slides. (Diva 1 Id No.: D1- HM9)</p> <p> <i>Paratype (Allotype):</i> 1 ♀, 1.6 mm, Area 4, Station #340 (EBS 09): 18°18.3’S 004°41.3’E to 18°19.4’S 004°41.9’E, 5395 m depth; ZMH K-40842. (D1- HM8)</p> <p> <i>Paratypes:</i> 1 ♂, 1.2mm, Area 5, Station #344 (EBS 10): 17° 06.2' S 004° 41.7' E to 17° 07.5' S 004° 42.3' E, 5415 m depth; ZMH K-40841 A–L, 12 slides. (D1- HM1). 1 juvenile (stage IV) 1.1mm (D1- HM3) and 1 juvenile (stage II) 0.7mm (D1- HM2) both from Area 6, Station #348 (EBS 11): 16° 18.1' S 005° 27.2' E to 16° 19.3' S 005° 27.2' E, 5387m depth; ZMH K-40843, K-40844.</p> <p> <i>Distribution</i>. Known only from the Angola Basin, Atlantic Ocean, 850 km west of Namibia. Depth range: 5387–5415 m.</p> <p> <i>Etymology.</i> Thylakogaster namibiensis sp. nov. is named after the sample locality: the new species was sampled 850 km westwards of the African coast off Namibia, in the Atlantic Ocean.</p> <p> <i>Diagnosis</i>. Cephalothorax-pereon length 3 times longer than wide. Antenna 1 of copulatory male consisting of 3 articles in peduncle and 12 in flagellum, aesthetascs present on articles 9–13 (formula: P3–F12[A8–12]). Article 3 length 1.1 article 2 length. Antenna 2 with 6 articles in peduncle and 11 in flagellum. Pleotelson length 0.66 cephalothorax-pereon length, length 1.34 width. Pleotelson with 30–40 simple spines developed on each lateral half. Uropods mace-like, broadened, inserting beneath broad keel close to rounded tip of pleotelson. Pleotelson nearly as long as broad, with rounded tip and small disto-medial projection, laterally expanded into 2 huge bumps on either side of frontal indentation.</p> <p> <i>Description of male (description of pereopods from juvenile paratypes):</i> Body (Fig. 1a–d) compact, cephalothorax-pereon length width 1.51, dorsoventrally flat and convex, unpigmented.</p> <p>Cephalothorax (Fig. 1a, b, e) rounded, length 0.27 cephalothorax-pereon length. Clearly visible fronsclypeal ridge developed anteriorly. Cephalon fused completely to first pereonite. Antennal insertion located on small projection on dorso-lateral surface.</p> <p>Pereon (Fig. 1a, b) with 1–2 spines on lateral margins of pereonites 1–7 next to coxae. Pereonites 1–3 of subequal proportions. Pereonite 3 widest. Pereonites 4–7 decreasing in length, with one or 2 small simple spines on ventral margins.</p> <p>Pleotelson (Fig. 1a, d, e, g) nearly as long as wide, length 0.66 cephalothorax-pereon length (measured basis of Plt to apex), with rounded tip; located dorsally above pereon and covering more than last 6 pereonites; laterally expanded into 2 huge bumps on either side of a frontal indentation. Pleotelson with 30–40 simple spines on each lateral side, often broken off at ends. Frontal indentation spineless. Uropods tiny, positioned on projecting lobes on ventral side close to pleotelson tip. Comb-like row of thin, unequally bifid setae below insertion of uropods (Fig. 1c)on both posterior margins (Fig. 1d). Setae more closely together than lateral cuticular spines on pleotelson. Both setae and spines increasing in length from tip to basis of pleotelson.</p> <p>Pleopods 1 and 2 in a posterio-dorsal position due to rounded form and position of pleotelson. Pleotelson covered entirely with spines in both sexes. External surfaces of male pleopods 1 and 2 equipped with single rows of spines. Surface of female operculum completely covered with strong spines.</p> <p>Antenna 1 (Fig. 2c, d): about as long as cephalothorax-pereon length, inserting dorso-medially at basis of A2. 3 articles in peduncle: article 1 with 1 broom seta and 1 short simple seta on disto-frontal margin (Fig. 2f). Article 2 with 1 plumose seta on disto-ventral margin. Article 3 without setae. Length ratio of peduncle articles: 1:0.7:0.8. Flagellum composed of 12 articles. Article 1 short, second article elongated, article 12 tiny (Fig. 2e). Length ratio of flagellar articles: 1:5.5:2:2.2:2:2.5:2.5:2.8:2:1.5:2.2:0.25. Flagellar articles with 1–2 fine simple seta. Flagellar articles 8–12 with 1 single aesthetasc each.</p> <p>Antenna 2 (Fig. 2b): length 2.0 cephalothorax-pereon length. Peduncle with 6 articles (Articles 1 broken off, article 2 damaged during dissection). Articles 1–4 short (only articles 2–4 are illustrated). Article 3 with 1 small seta on ventral side. Article 4 with 2 unequally bifid setae on dorsal side. Articles 5 and 6 elongated, bearing unequally bifid setae at irregular intervals (Articles 5 partially fractured in illustrated specimen). Setae insert with slight elevation, most setae broken off. Length ratio of peduncle articles: 1:1.1:0.5:1:8:14. Flagellum with 11 articles, first and second elongated, remaining articles smaller, subequal. Flagellar articles 1, 3 and 5 without setae, 8 with 1, articles 2, 4, 7, 9 and 10 with 2 setae. Article 6 with 3 small and thin simple setae. Article 11 with 5 long, thin setae on distal end (Fig. 2a).</p> <p>Mandibles (Fig. 2g, h): proximally broad, tapering distally, without palp. Left mandible with long, slender, simple, medial seta. Right mandible with 1 short, simple seta medially and 1 slender, simple spine and short, strong spine laterally.</p> <p> Left incisor process with 5 teeth with cuticular wrinkles, ventral-most tooth largest, remaining teeth decreasing in size to dorsal side. <i>Lacinia mobilis</i> of left mandible broad, bearing 4 prominent teeth and 1 small tooth. Setal row of 4 curved spines and 2 slender, simple setae. Molar process finger-like, with 7 long, slender, simple setae.</p> <p>Right incisor process with 5 broad teeth of approximately same size, with cuticular wrinkles. Setal row of 5 curved spines, each spine serrated with 7 strong, short teeth; between curved spines some long and slender simple setae. Molar process finger-like, distal with 12 long, slender, simple setae.</p> <p>Maxilla 1 (Fig. 3e, f): Outer lobe of left maxilla 1 terminally with 11 spine-like setae: 6 stout and rough serrated setae, 4 long setae serrated and equipped with a dense comb of fine setae and 1 simple, fine, ventral seta. Outer lobe of right maxilla 1 terminally with 11 spine-like setae of comparable size: 7 stout and rough serrated setae, 2 setae serrated and equipped with dense comb of fine setae and ventrally 2 simple fine setae. Inner lobe of right maxilla 1 with 3 long and slender setae.</p> <p>Maxilla 2 (Fig. 4a, b): middle and outer lobe subequal in length. Tips of middle and outer lobes with 3 long, single, side, plumose seta and 1 simple, media seta. Outer lobe also with 2 combs of 4 fine setae laterodistally. Inner lobe shorter and broader than middle and outer lobes. Inner lobe with 11 simple setae: 8 short on tip and 3 long on median margin. Proximal to these with 3 long and 7 small additional setae.</p> <p>Maxilliped (Fig. 3a–d): epipodite small and triangular, carrying numerous fine setae on its surface and lateral margins, reaching only half of length of lobe. Lateral margin of lobe irregularly rounded, tip truncated, with simple setae. Distal part of lateral margin of lobe with row of fine setae. Medial margin of lobe straight. Lobes connected by 5 (left lobe 3, right lobe 2) retinacula (Fig. 3b, d). Retinacula with 5 prominent teeth and cuticular wrinkles. Palpus long and slender, about twice as long as lobe. Palpus tapering distally, composed of 5 articles. All articles with numerous fine setae on surface and lateral margins. Length ratio of articles: 0.3:0.7:1:1.5:1.2. All articles with thin, long setae as follows: 1 with single seta, 2 with 2, 3 with 4, 4 with 3 and 5 with 7 long setae.</p> <p>Pereopods (Fig. 4c–f): all pereopods insert on elongated lateral projection (Fig. 1a, e)</p> <p>Pereopod 1 (Fig. 4d): robust, length 1.3 cephalothorax-pereon length, subchelate with prominent, strong, unequally bifid setae of altering length on basis, ischium, merus and carpus. Basis with 1 unequally bifid seta on ventral margin. Ischium length 0.5 basis length, with 3 unequally bifid setae and 2 simple setae on ventral and 2 unequally bifid setae on dorsal margin. Merus short, with 6 unequally bifid setae, 3 on ventral and 3 on dorso-frontal margin. Carpus elongated, longer than basis, with 11 strong unequally bifid on ventral margin opposite to propodus and dactylus and 5 additionally unequally bifid setae on proximal medial surface.</p> <p>Propodus with row of 5 fine setae on ventral and 2 simple setae on dorsal margin. Dactylus with 9 long simple setae (Fig. 4f).</p> <p>Pereopods 2–7 slender, sub-similar walking legs. Coxa of pereopods 2 to 7 recognizable but fused with pereonites and only slightly movable. All coxae with 3–5 strong, simple spines.</p> <p>Pereopod 2 (Fig. 4c): length 1.4 cephalothorax-pereon length. Basis with 3 slender simple setae on ventral margin (see remarks). Ischium as long as broad, with 5 unequally bifid setae, 1 on ventral and 4 on dorsal margin. Merus with 2 setae on ventral and 4 setae on dorsal margin. Carpus long, slender, with row of long unequally bifid setae and long simple setae on ventral margin opposite to propodus. 4 unequally bifid setae dorsally and additionally 1 broom seta distally. Propodus narrower, but as long as carpus. Propodus with more than 18 long, robust, unequally bifid setae. Terminally with 7 slender, simple setae. Dactylus with 7 long simple setae (Fig. 4e).</p> <p>Pleopods (Fig. 5a–e): male pleopods 1 and 2 forming posterio-ventral part of pleotelson, completely covering branchial cavity.</p> <p>Pleopod 1 (Fig. 5a): male pleopod 1, length 3.7 width, lateral margins nearly parallel, tapering in the distal fifth. Ventral surface with row of 4 strong spines each. Disto-lateral corners with 8 small, hair-like setae.</p> <p>Pleopod 2 (Fig. 5e): male pleopod 2, length 3.0 width,with 2 rows of 7 cuticular spines on external surface. Lateral margin with dense row of long, slender setae. Stylet (endopodite) short, robust, stylet length 0.33 protopod length. Exopodite forms a small lobe disto-medial of endopodite.</p> <p>Pleopod 2 (Fig. 1g): female pleopod 2 tapering distally, truncate proximally, completely covering branchial cavity. External surface with irregularly distributed cuticular spines.</p> <p>Pleopod 3 (Fig. 5b): exopodite elongated and hemispherical, 2-articulated, lateral and disto-medial margins with rows of numerous long, hair-like setae, distal article with 1 simple seta apically. Endopod length 1.4 width, distally rounded, with 3 strong, plumose, terminal setae and hair-like, medial and apical setae.</p> <p>Pleopod 4 (Fig. 5c): transparent, small, length 2.5 width, without setae, exopodite slender.</p> <p>Pleopod 5 (Fig. 5d): transparent, small, length 2.8 width ratio, without setae, exopodite reduced.</p> <p>Uropods (Fig. 1c, f): inserting beneath broad keel on ventral margin of branchial cavity close to tip of pleotelson, uniramous, cylindrical. Distal part swollen, rounded, with 5 hair-like setae.</p> <p> <i>Remarks.</i> The copulatory male described bares only the antenna 1 and the first pereopods. The rest of the long appendages were broken off at their basis. For description of the lost antenna and the pereopod 2, a comparably large paratype was used. Except for the individuals described here, the long and extremely fragile antenna 1, antenna 2 and pereopods 3 to 7 were broken off on all specimens of <i>T. namibiensis</i> sp. nov., or the specimens were significantly smaller. Male and female of <i>T. namibiensis</i> show no sexual dimorphism, besides the female may be expanded if oostegites are developed.</p> <p>The inner lobe of the left maxillula and the distal part of the merus of pereopod 2 were damaged during dissection. The cuticular wrinkles on the surface of pleopod 3 may be artefacts.</p>Published as part of <i>Brenke, Nils & Buschmann, Anika, 2009, Thylakogaster namibiensis sp. nov. (Isopoda: Asellota: Janiroidea), a new species of Haplomunnidae from the southeast Atlantic deep sea *, pp. 381-394 in Zootaxa 2096 (1)</i> on pages 384-390, DOI: 10.11646/zootaxa.2096.1.23, <a href="http://zenodo.org/record/5323453">http://zenodo.org/record/5323453</a>
Contribution of Information and Communication Technology (ICT) in Country’S H-Index
No full textThe aim of this study is to examine the effect of Information and Communication Technology (ICT) development on country’s scientific ranking as measured by H-index. Moreover, this study applies ICT development sub-indices including ICT Use, ICT Access and ICT skill to find the distinct effect of these sub-indices on country’s H-index. To this purpose, required data for the panel of 14 Middle East countries over the period 1995 to 2009 is collected. Findings of the current study show that ICT development increases the H-index of the sample countries. The results also indicate that ICT Use and ICT Skill sub-indices positively contribute to higher H-index but the effect of ICT access on country’s H-index is not clear.Cite as:
FARHADI, M., SALEHI, H., EMBI, M. A., FOOLADI, M., FARHADI, H., AGHAEI CHADEGANI, A., & ALE EBRAHIM, N. (2013). Contribution of Information and Communication Technology (ICT) in Country’S H-Index. Journal of Theoretical and Applied Information Technology, 57(1), 122-127
Lah–Ribarič type inequalities for (h, g; m)-convex functions
No full textRecently introduced new class of (h, g; m)-convex functions unifies a certain range of convexity, thus allowing the generalizations of know results. In this paper we prove Lah–Ribarič type inequalities for (h, g; m)-convex functions from which we obtain inequalities of Hermite–Hadamard, Fejér, Giaccardi, Popoviciu and Petrović. © 2021, The Author(s) under exclusive licence to The Royal Academy of Sciences, Madrid
Mrs. H. M. Evers
No full textNewspaper Article - 'Mrs. H. M. Evers' - Mrs. Evers hopes she can learn much about the living conditions here and the possibilities for the Dutch settlers.Alberta Women's Institutes; AWI CollectionMRS. H. M. EVERS
I bring out his capital immediately
and until such time as their capital
is released things are quite
difficult. "' There are very few
provinces in Canada that will supply
the Dutch settlers with a loan",
Mr. Jensma stated.
On her arrival here Mrs. Evers
i was astounded at the unusua1.
building of the city and the large
• ields of wheat. " Of course we have
wheat too, but ours is only a small
country so we have to be very
economical and not spend out
land too freely". The buildings are
much taller and narrower, especially
in the cities. Wood is very
expensive so most of the homes are
built of brick and concrete with
corrugated steel and tile roofs.
Give True Picture
In her travels across the country
Mrs. Evers hopes she can lenrn
much about the living conditions
here and the possibilities for the
Dutch settlers so when she re-
| turns to her homeland she will b- i
able to give the women of Holland
all the information possible and
prepare them for their great adventure.
Mrs. Evers and her family reside
on a 150 acre farm in the
northern part of the country. Her
daughter Tjaakje is a teacher in
home economics and her son.
Luken, works on the farm.
Besides serving on the immigration
board she is a member of the
international board of the YWCA;
the international Council of Women:
international corporation of
Dutch Country Wives: the international
organization of the Associated
Country Women of thr
World: and a member of the Women's
Institutes.
She will leave on Tuesday for
Toronto, where she will be met by
Mr. W. Blome. who is with the
Netherlands Immigration Board
in Ottawa.
A doctor declares the British
people are taking 10.000,000 aspirin
tablets a day
Altitudinal distribution of alien plant species in the Swiss Alps
No full textIn summer 2003 we recorded the presence and abundance of alien plant species at 232 sites (107 railway stations and 125 road sites) along mountain passes in the Swiss Alps. The altitudinal distribution of species was related to the current abundance of the species in Switzerland and time since introduction. A total of 155 alien taxa were recorded. Numbers of species per site declined exponentially with altitude, and only a few species were found in the alpine zone (> 2000 m). In contrast, species richness among comparable native taxa appeared to be nearly independent of altitude over the range investigated. Maximum altitude reached by alien species was related positively to both total area occupied in Switzerland and to time since introduction. A comparison of the results with earlier records suggests that many species, particularly those previously restricted to low or intermediate altitudes, have advanced their altitudinal limits over the past few decades. Various hypotheses are presented to explain the declining abundance of alien species with altitude: low-altitude filter effects, low propagule pressure, and genetic swamping of peripheral populations at higher altitudes. However, at present we do not have sufficient evidence to determine the relative importance of these effects. We conclude that invasion into mountain areas such as the Swiss Alps tends to proceed rather slowly, though the process may be accelerated by climatic warming. For this reason, further research to investigate the processes determining how plants invade mountain areas is urgently needed. And more generally, investigations into the distribution of alien species along strong altitudinal gradients may provide valuable insights into the mechanisms driving the spread of alien organisms. (c) 2005 Rubel Foundation, ETH Zurich. Published by Elsevier GmbH. All rights reserved
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