615 research outputs found
Corethrella (Corethrella) bipigmenta Borkent & Grafe, new species
No full text<i>Corethrella</i> (<i>Corethrella</i>) <i>bipigmenta</i> Borkent & Grafe, new species <p>(Figs. 2 C, 4D, 6D, 8D, 9D, 12D, 13D, 15B)</p> <p> DIAGNOSIS: <i>Male adult.</i> Unknown. <i>Female adult.</i> Only extant species of <i>Corethrella</i> in the Palaearctic, Oriental, Oceanian and northern Australasian Regions with the combination of no pigmentation distal to the single distinct midlength wing band (no subapical band) (Fig. 12D), flagellomeres 1–4 elongate, each similar in length to flagellomere 5 (Fig. 8 D), with non-discrete darker pigmentation on the basal 0.5 of the midfemur and basal 0.3–0.4 of the hind femur, uniformly yellow or light brown hind tibia (Fig. 9D), and abdominal tergites each with anterolateral darker pigmentation (Fig. 13D). Only extant species in Borneo with the combination of flagellomeres 1–4 elongate, each similar in length to flagellomere 5 (Fig. 8 D) and palpal segments 1 and 2 dark brown and contrasting with pale segments 3 and 4 (5 grading from pale to medium brown) (Fig. 6 D).</p> <p> DESCRIPTION: <i>Male adult</i>. Unknown. <i>Female adult.</i> Descriptive statistics: See Tables 1 –5. <b>Head</b>: Outline in anterior view somewhat circular (Fig. 6 D). Coronal suture elongate, extending ventrally past ommatidia. Two large setae on frons between ventromedial area of ommatidia (as in Fig. 16B). Antenna uniformly medium brown; pedicel with distinctive elongate, stout setae. Antennal flagellomeres as in Fig. 8 D; sensilla coeloconica on flagellomeres 1–2, 9–13, only flagellomere 1 with more than one; flagellomere 13 with well-developed apical bifurcation. Clypeus somewhat square. Mandible with moderately small, pointed teeth. Palpus (Fig. 6 D) with segments 1–2 dark brown, segments 3–5 light brown, segment 5 darker apically; segment 3 swollen apically. <b>Thorax</b> (Fig. 9D): Scutum, scutellum mostly light to medium brown, contrasting with darker brown pleura; pale sclerites around base of wing. Posterior portion of dorsocentral row with 2 elongate setae situated somewhat lateral to one another. Prescutal suture elongate, thick, uninterrupted, extending to near dorsocentral row of setae.</p> <p> Anterior anepisternum divided diagonally by sinuous suture, dorsal portion about equal to ventral portion. Ventral portion of posterior anepisternum triangular, uniformly brown, with anterodorsal margin not thick. <b>Wing</b> (Fig. 12D): Apex of R2 slightly distal to apex of M1. Anterior margin with differently, discretely pigmented scales (indicating anterior margin of midlength band), with midlength band, with darker more basal scales restricted to vein C, Sc, slightly in more posterior veins, with basal scales on posterior margin of wing dark; veins (other than costa and wing margin) with well-developed scales. Halter medium brown, equal to or slightly lighter than scutellum. <b>Legs</b> (Fig. 9D): Light brown, with about basal 0.5 of forefemur slightly darker, about basal 0.5 of midfemur darker, about basal 0.3–0.4 of hind femur darker; with darker pigmentation not discrete. With only slender setae, lacking scales. Midleg with thick, subapical setae on each of at least tarsomeres 1–3. Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Empodia thick. <b>Abdomen</b> (Fig. 13D): Tergites 2–7 pale or light brown with anterolateral corners more darkly pigmented, tergite 8 pale or light brown, sternites light brown with sternites 2–6 with anterior portions medium brown, posterior margins pale, sternites 7–8 medium brown. Cercus medium light brown.</p> <p> <i>Immature stages</i>. Unknown.</p> <p> DISTRIBUTION AND BIONOMICS: <i>Corethrella bipigmenta</i> is known only from steep terrain in the mature mixed dipterocarp forest (Figs. 1 E, F) of Ulu Temburong National Park, Brunei, at elevations of 50–120 meters (Fig. 15B). Three females in the type series were collected on 22-VII-2006 from a calling male <i>Megophrys nasuta</i> (Schlegel) at 8:30 PM (Fig. 2 C). A photograph by the second author (Fig. 2 C) shows numerous identical looking female <i>Corethrella</i> on and surrounding the frog: seven were on the legs, two were on the back, and at least 10 were on nearby substrate. Further specimens were collected from other <i>M. nasuta</i> and one other frog species (Table 7). This species has not yet been collected with a frog-call trap.</p> <p> TAXONOMIC DISCUSSION: The three type specimens of <i>C. bipigmenta</i> were noted by Borkent (2008) in the taxonomic discussion of <i>C. nippon</i> (but mistakenly stated as coming from Sungai Belalong). This species is very similar to <i>C. nanoantennalis</i> but differs in the relative lengths of flagellomeres 1–4.</p> <p> <i>Corethrella bipigmenta</i> is placed in the <i>drakensbergensis</i> species group for the same reason that <i>C. nanoantennalis</i> was placed there, along with the same caveats (Fig. 19). However, it appears that this species has synapomorphy 40 (pedicel with strong setae), which would place it elsewhere in the phylogeny of the Corethrellidae. We are inclined however, to question the validity of this synapomorphy – it is often difficult to interpret consistently in specimens and its distribution may have been misrepresented by Borkent (2008).</p> <p> TYPES: Holotype, female adult on microscope slide, labeled " HOLOTYPE <i>Corethrella bipigmenta</i> Borkent and Grafe ", "Tributary of Sungai Temburong in Temburong district of Brunei Darussalam, 115° 09'E, 4° 33'N, 22-VIII-2006, U. Grafe, CD2069" (CNCI). Paratypes on microscope slides: 2 Ƥ, labeled as for holotype (1, CNCI; 1 UBD). Paratypes on pins: 2 Ƥ, from Kuala Belalong, Ulu Temburong NP, Brunei, 50 m, 23-VII-2007 (CNCI); 4 Ƥ, from Sungai Esu, Ulu Temburong NP, Brunei, 60 m, 11-VII-2008 (CNCI); 2 Ƥ, from Sungai Baki, Ulu Temburong NP, Brunei, 120 m, 18-VII-2008 (1 CNCI; 1 UBD); 1 Ƥ, Sungai Mata Ikan, Ulu Temburong NP, Brunei, 110 m, 10-VII-2008, (UBD).</p> <p> DERIVATION OF SPECIFIC EPITHET: The name <i>bipigmenta</i> (two, pigment) refers to differently pigmented palpal segments 1–2 (dark) and segments 3–5 (lightly pigmented) of females of this species.</p>Published as part of <i>Borkent, Art & Grafe, Ulmar, 2012, The Frog-Biting Midges of Borneo — From Two to Eleven Species (Corethrellidae: Diptera), pp. 1-45 in Zootaxa 3279</i> on pages 10-11, DOI: <a href="http://zenodo.org/record/210864">10.5281/zenodo.210864</a>
Research article
No full textBackground: In many species of birds, pair bonded males and females precisely co-ordinate their vocalisations to form duets. Duetting behaviour, although still somewhat of an enigma, is thought to function primarily in territorial defence and mate guarding. We identify an additional function of duetting in an afrotropical bird, the tropical boubou (Laniarius aethiopicus), that uses one duet type as a postconflict display probably to advertise victory to other boubous. Results: We simulated intrusions into boubou territories in the field in Ivory Coast, West Africa using playbacks of four different types of boubou duets to test the use of the presumptive acoustic victory display before, during and after playbacks. These staged encounters resulted in either retreat of the focal birds during playback or continued presence accompanied by vocal displays after playback had ceased. Losers of encounters never sung after retreating whereas 11 out of 18 pairs sung the presumptive victory duet after the encounter. Analysis revealed that the presumptive victory display was sung significantly more often after than before or during the playback treatment
Carnivorous <i>Nepenthes</i> pitcher plants are a rich food source for a diverse vertebrate community
No full textCarnivorous pitcher plants capture insect prey to acquire essential nutrients while growing on extremely poor soils. A few individual species have evolved mutualistic relationships with small mammals that visit the traps to harvest nectar, and in return leave faecal droppings in the pitchers. Here we report that a diverse guild of nectar-harvesting vertebrates visits pitchers of two common lowland Nepenthes species without providing any obvious benefit for the plants. Over four consecutive field seasons, we observed four species of sunbirds and one species of tree shrew drinking nectar from pitcher plants. Foraging activity was highest in the morning and late afternoon. Van Hasselt’s, Brown-throated and olive-backed sunbirds were regular and highly abundant pitcher visitors in two different field sites. A crimson sunbird and a lesser tree shrew were each observed harvesting nectar on one occasion. The vertebrates harvested nectar from the pitcher rim (peristome) of N. rafflesiana and from the underside of the pitcher lid of N. gracilis. A comparison of the nectar production of these and three further sympatric species revealed exceptionally high quantities of nectar for N. rafflesiana. Other factors such as plant and pitcher abundance and the habitat preferences of the observed vertebrates are likely to also play a role in their choice to visit particular species. This is the first account of a case of obvious nectar robbing from Nepenthes pitchers by a guild of species that are too large to serve as prey, while the pitcher size and shape prevent faecal droppings from reaching the pitcher’s inside. This interaction provides an example of a possible starting point for the evolution of the elaborate mutualistic relationships observed in some species. Follow-up adaptations of pitcher shape could enable the plants to catch the droppings of their visitors and turn an exploitative relationship into a mutualism
Ideabuilding, Occupation and construction: Christoph Grafe in a conversation with Stephen Bates and Jonathan Sergison / Ideebouwen, bewoning en constructie: Christoph Grafe in gesprek met Stephen Bates en Jonathan Sergison
No full textArchitectureArchitectur
Acht jaar na Nine+One: Een gesprek tussen Mark Linnemann, Matthijs Bouw, Mechtild Stuhlmacher, en Christoph Grafe / Eight years after Nine+One: a conversation between Mark Linnemann, Matthijs Bouw, Mechtild Stuhlmacher and Christoph Grafe
No full textIn 1997 lanceerde Kristin Feireiss, de toenmalige directrice van het Nederlands Architectuurinstituut (NAi) een tentoonstellingenreeks over toen jonge architectenbureaus onder de titel 'Nine+One'. In haar voorwoord voor de catalogus zette Feireiss haar redenen uiteen voor dit initiatief waarmee ze de aandacht wilde opeisen voor een nieuwe generatie architecten in Nederland. Hoe wel de architecten grofweg een generatie vertegenwoordigden en vrijwel allemaal in de jaren tachtig aan de Technische Universiteit Delft waren opgeleid, was er volgens Feireiss niet sprake van een nieuwe beweging of school, maar van een reeks individuele zoektochten, gevoed door een 'sceptische houding ten opzichte van allesomvattende theorieen' voorbij het 'Modernisme zonder dogma' van een generatie eerder. Ondanks deze nadruk op de verscheidenheid van de agenda's van de afzonderlijke bureaus werd de tentoonstelling (die na de presentaties in het NAi op een reis over de we reid werd gestuurd) vooral gezien als een teken van een tendens en als een presentatie van een nieuwe, frisse, onbevangen en lichtvoetige Nederlandse architectuur, en als zodanig markeerde het publiciteitsinitiatief van de NAi-directrice mogelijk het hoogtepunt van de party van de Nederlandse architectuur van de jaren negentig. Acht jaar later vormt de veranderde situatie van de architectuur en de samenleving in Nederland de achtergrond van een gesprek aan een Amsterdamse eettafel. Zijn de thematieken waarmee jonge Nederlandse architecten zich in de jaren negentig profileerden nog relevant in de context van de gepolariseerde samenleving van na 2001 en 2002? En welke perspectieven openen zich, nu de dynamiek van de hoogconjunctuur verdwenen is?ArchitectureArchitectur
Figure 7 in Carnivorous Nepenthes pitcher plants are a rich food source for a diverse vertebrate community
No full textFigure 7. Large nectar droplets (arrow) regularly accumulate on the lower lid surface of Nepenthes gracilis pitchers early in the morning.Published as part of <i>Bauer, Ulrike, Rembold, Katja & Grafe, T. Ulmar, 2015, Carnivorous Nepenthes pitcher plants are a rich food source for a diverse vertebrate community, pp. 483-495 in Journal of Natural History 50</i> on page 491, DOI: 10.1080/00222933.2015.1059963, <a href="http://zenodo.org/record/3985530">http://zenodo.org/record/3985530</a>
Enhancement of K+ conductance improves in vitro the contraction force of skeletal muscle in hypokalemic periodic paralysis
No full textAn abnormal ratio between Na+ and K+ conductances seems to be the cause for the depolarization and paralysis of skeletal muscle in primary hypokalemic periodic paralysis. Recently we have shown that the k+ channel opener cromakalim hyperpolarizes mammalian skeletal muscle fibers. Now we have studied the effects of this drug on the twitch force of muscle biopsies from normal and diseased human skeletal muscle. Cromakalim had little effect on the twitch force of normal muscle whereas it strongly improved the contraction force of fibers from patients suffering from hypokalemic periodic paralysis. Recordings of intracellular K+ and Cl- activities in human muscle and isolated rat soleus muscle support the view that cromakalim enhances the membrane K+ conductance (gK+). These data indicate that K+ channel openers may have a beneficial effect in primary hypokalemic periodic paralysis
Atlantic trade and regional specialisation in nothern Spain 1550-1650: an integrated trade theory-institutional organisation approach
No full textBased on an in-depth study of the northern Spanish economy in the sixteenth and seventeenth centuries, this paper argues that commercial expansion was a major source of the diverging performance of European regions. It develops an approach that integrates insights from more recent trade theory with those from new institutional economics. New trade theory informs the analysis of changes at a macro-level - defined as traded quantities, the structure of (inter-) regional integration and specialisation, and the larger institutional framework. New institutional economics are the basis for the interpretation of developments at a micro-level defined as the strategies of merchant organisations and individual firms within that larger framework. The paper shows how macro-level changes impacted upon - and interacted with - micro-level structures and processes of adaptation. The integration of quantitative and qualitative analysis demonstrates that the Commercial Revolution transformed the European economy more through structural change than through increased availability of goods
Changes in intracellular ion activities induced by adrenaline in human and rat skeletal muscle
No full textTo study the stimulating effect of adrenaline (ADR) on active Na+/K+ transport we used double-barrelled ion-sensitive micro-electrodes to measure the activities of extracellular K+ (aKe) and intracellular Na+ (aNai) in isolated preparations of rat soleus muscle, normal human intercostal muscle and one case of hyperkalemic periodic paralysis (h.p.p.). In these preparations bath-application of ADR (10−6 M) resulted in a membrane hyperpolarization and transient decreasesaKe andaNai which could be blocked by ouabain (3×10−4 M). In the h.p.p. muslce a continuous rise ofaNai induced by elevation ofaKe to 5.2 mM could be stopped by ADR. In addition, the intracellular K+ activity (aKi), the free intracellular Ca2+ concentration (pCai) and intracellular pH (pHi) were monitored in rat soleus muscle. During ADRaKi increased, pHi remained constant and intracellular Ca2+ apparently decreased. In conclusion, our data show that ADR primarily stimulates the Na+/K+ pump in mammalian skeletal muscle. This stimulating action is not impaired in the h.p.p. muscle
Figure 3 in Prolonged parental behaviour by males of Limnonectes palavanensis (Boulenger 1894), a frog with possible sex-role reversal
No full textFigure 3. Embryonic development of the eggs of L. palavanensis. (a) The vegetal pole differentiates from the animal pole 24 h after fertilisation. (b) Neural folds develop, Gosner stage 15 (3 days old). (c) The head forms and the tail elongates around the yolk sac, Gosner stages 18–19 (4 days old). (d) Eyes become apparent and external gills are visible, Gosner stages 21–22 (6 days old). (e) The tadpoles are now sensitive to light, the eyes are completely formed and the gills are not visible anymore, Gosner stages 24–25 (9 days old). (f) The tadpoles are ready to hatch (10 days old).Published as part of Goyes Vallejos, Johana, Grafe, T. Ulmar & Wells, Kentwood D., 2018, Prolonged parental behaviour by males of Limnonectes palavanensis (Boulenger 1894), a frog with possible sex-role reversal, pp. 2473-2485 in Journal of Natural History 52 (37-38) on page 2479, DOI: 10.1080/00222933.2018.1539196, http://zenodo.org/record/517766
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