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Polydopamine and Cellulose: Two Biomaterials with Excellent Compatibility and Applicability
No full textIn recent decades, the role of poly(dopamine) in governing mussel adhesion has been gradually understood and exploited as a novel bio-mimicking adhesion concept. In parallel, the polysaccharide materials present a broad class of functional materials ranging from macro- to nanoscale components with broad variety in chemical structure, morphology and reactivity. The cross-over between both research fields enables the creation of fascinating materials with advanced engineering properties, where the (poly)dopamine serves as a general platform for the functionalization of polysaccharides. In this review, the role of poly(dopamine) in modification of cellulose and nanocellulose materials is discussed by means of several recent examples from literature. A broad variety of applications is presented, including bio-composites, nanoparticles and nanofibers, nanocomposites, hydrogels, aerogels, textiles, adhesives, films and papermaking applications. The review aims at stressing the viability of technical applications against a background of both the chemical and engineering aspects of dopamine-modified cellulose.Samyn, P (corresponding author), Hasselt Univ, Inst Mat Res Appl & Analyt Chem, Agoralaan Gebouw D, B-3590 Diepenbeek, Belgium.
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Actinopyga caerulea Samyn, Vandenspiegel & Massin, 2006, sp. nov.
No full text<i>Actinopyga caerulea</i> sp. nov. <p>(Figures 1 A–J, 2A–E, 3A–E, 4A–G, 5; plate 1A–C)</p> <p> <i>Actinopyga crassa</i>; Cherbonnier & Féral 1984: 664, fig. 3 A–K; Féral & Cherbonnier 1986: 70 –71; Erhardt & Moosleitner 1995: 1153 (non <i>A. crassa</i> Panning, 1944)</p> <p> <i>Actinopyga</i> (?) <i>bannwarthi</i>; Erhardt & Baensch 1998: 1076 (non <i>A. bannwarthi</i> Panning 1944)</p> <p> <i>Name­bearing types</i></p> <p>Holotype, RMCA 1803; Paratype 1, CNDRS 2004.09; Paratype 2, RBINS IG 30376; Paratype 3, MNHN EcHo 8081; Paratype 4, NHM 2005.2405.</p> <p> <i>Material examined</i></p> <p>Union des Comores (Grande Comore, Ikoni), 22.XI. 2003, 37 m depth, coll. Y. Samyn & D. VandenSpiegel, RMCA 1803 (holotype); Union des Comores (Grande Comore, H.L.M Langouste), 11.X. 2004, 28 m depth, coll. Y. Samyn, D. VandenSpiegel & C. Massin, CNDRS 2004.09 (paratype 1); Union des Comores (Grande Comore, Itsandra), 20.XI. 2003, 23 m depth, coll. Y. Samyn & D. VandenSpiegel, RBINS IG 30376 (paratype 2); Union des Comores (Grande Comore, Aérodrome), 16.V. 2005, 26 m depth, coll. Y. Samyn & D. VandenSpiegel, NMHN EcHo 8081 (paratype 3); Union des Comores (Grande Comore, Itsandra), 16.V. 2005, 21 m depth, coll. Yves Samyn & D. VandenSpiegel, NHM 2005.2405 (paratype 4); Papua New Guinea (Madang Province, Madang’s Reef, Wongat Island), 05.X. 1996, 25 m depth, coll. C. Massin, RBINS, IG 28 455/22.</p> <p> <i>Type locality</i></p> <p>Union des Comores, Grande Comore, Ikoni.</p> <p> Type material (2 syntypes) of <i>Actinopyga serratidens</i> var. <i>bannwarthi</i> Panning, 1944: ZMH E5902 (Zoologishes Institut und Zoologisches Museum der Universität Hamburg); Egypt (Suez), 1913, depth unknown, coll. Dr E. Bannwarth.</p> <p> Non type material (1 specimen) of <i>A. mauritiana</i> (Quoy & Gaimard, 1833) (misidentified as <i>A. bannwarthi</i> Panning, 1944 by Cherbonnier (1988)): Madagascar (Nosy Be, Andilana), 20.VIII.1959, coll. G. Cherbonnier, EcHh 5082 (Muséum National d’Histoire Naturelle, Paris, France).</p> <p> Non type material (2 specimens) of <i>A. crassa</i> Panning, 1944: Seychelles (Mahé), 07.IX.1969, coll. Mission zoologique MRAC­ULB, RMCA 1186.</p> <p> <i>Description</i></p> <p> Very large species; living specimens up to 400 mm long and 140 mm wide mid­body; preserved specimens from 225 to 280 mm long and from 85 to 110 mm wide mid­body. Body loaf­shaped with slight ventral flattening (more or less cylindrical with some distal tapering). Colour in life bluish with patches of white devoid of tube feet at anterior and posterior ends and, discontinuously, along sides (Plate 1). Colour in type material in alcohol largely preserved, but faded to dull brown in specimen from Papua New Guinea. White patches remain clearly visible on all specimens. Body wall smooth, up to 14 mm thick. Mouth ventral, surrounded by 15–18 large, peltate, uniformly bluish­grey tentacles, in turn surrounded by a stout collar of bluish papillae, fused at their base. Anus terminal, guarded by five prominent, calcareous, teeth, each bearing numerous tubercles. Ventral tube feet stout, distributed unevenly, <i>albeit</i> somewhat concentrated in ambulacral areas. Dorsal “papillae” large, conical at base, near cylindrical at top; bluish at base, slightly lighter at top; scattered over ambulacral and interambulacral areas, though absent in white zones. Cuvierian organ absent. Single, club­shaped Polian vesicle, about one seventh of length of preserved animals. Stone canal and associated madreporite not observed in all the specimens studied. Gonad observed only in the specimen from Papua New Guinea. Calcareous ring huge, radial pieces about twice as large as interradial pieces (Figure 1 A). Details of surface of calcareous ring obscured by thick layer of tissue.</p> <p> <i>Ossicles</i>: Tentacles with rods only; base of tentacles with few, straight to slightly curved, smooth rods, 50–90 m long (Figure 1 B); tip of tentacles with similar but larger rods, up to 500 m long (Figure 1 C, D), occasionally distally branching (Figures 1 C, 3A). Ventral body wall with rosettes of various forms, some elongated with endings swollen, others wider and more spiny, 15–65 m long (Figures 1 E, 3B). Dorsal body wall with small rosettes that have their endings swollen, 20–60 m long (Figures 1 F, 3C) and elongated rod­like spiny rosettes, 255– 100 m long (Figures 1 G, 3D). The proportion of rosettes with swollen endings versus spiny rod­like rosettes as well as the size of the rosettes are highly variable within a single specimen, depending on site of bivium sampled. The same phenomenon occurs in specimens coming from different geographic localities: holotype from Comoros Islands with more spiny ossicles in dorsal body wall than the specimen from Papua New Guinea. Base of dorsal papillae with rosettes and rodlike rosettes, 25–65 m long, as well as dichotomously branched spiny rods, 100–160 m long (Figures 1 J, 3E). Tip of dorsal papillae with spiny rods of various form; from simple to complex branching, 50–200 m long (Figures 1 H, 4A). Ventral tube feet with smooth rods, 25–40 m long, spiny rods, 40–150 m long, and stout spiny rods, 100–140 m long, with perforated extremities (Figures 2 A, 4B); terminal disc, up to 1,000 m across, composed of several pieces; centrally several perforated plates with large holes (Figure 4 C) surrounded by 10–12 perforated plates with smallest holes at periphery (Figure 4 D). Cloaca with spiky rods, similar in shape as those from dorsal papillae, 50–100 m long (Figures 2 D, 4E). Longitudinal and cloacal retractor muscles with simple, smooth, occasionally branched rods, 35–55 m long (Figures 2 B, C, 4F, G). Gonad with spiny, branched rods, 160–250 m long (Figure 2 E).</p> <p> <i>Etymology</i></p> <p> The name <i>caerulea,</i> Latin, refers to the unique blue colour of the species.</p> <p> <i>Ecology</i></p> <p>This species is characteristic of somewhat deeper tropical waters; it has been observed from 12 to 45 m. The species is predominantly a detritus/deposit feeder on coral patches on the outer slope of coral reefs; it forages actively during the day.</p> <p> <b>PLATE 1.</b> <i>Actinopyga caerulea</i> sp. nov. as photographed <i>in situ</i> in Comoros (A), Sulawesi (B), Bali (C) and Papua New Guinee (D). (Picture A by D. VandenSpiegel; B by D. Lane; C by R. Myers and D by P. Colins).</p> <p> <i>Geographic distribution</i></p> <p> Tropical Indo­Pacific; confirmed sightings have been made in Thailand (see Erhardt & Moosleitner 1995, as <i>A. crassa</i>), the Philippines (see Erhardt & Baensch 1998, as <i>A.</i> (?) <i>bannwarthi</i>), Indonesia [Bali (Myers pers. comm.) and Sulawesi (Lane pers. comm.)], Papua New Guinea [Kavieng (Colin pers. comm), Hansa Bay (Colin pers. comm.) and Madang (present paper)], New Caledonia (see Féral & Cherbonnier 1986, as <i>A. crassa</i>) and the Archipelago of the Comoros (type locality). Figure 5 shows the known distribution of this species, including locations requiring confirmation of identification.</p> <p> <i>Discussion</i></p> <p> <i>Actinopyga caerulea</i> sp.nov belongs to what Panning (1944) has termed the ‘ <i>echinites</i> group. It shares with <i>A. bannwarthi</i> the presence of spiny rosettes (cf. Panning 1944, Fig. 22, p. 54). However, rosettes from <i>A. bannwarthi</i> are less spiny and have many more lateral extensions than those from <i>A. caerulea.</i> Another striking difference between the two species lies in the colouration: the two syntypes of <i>A. bannwarthi</i> are uniform dark chocolate brown dorsally (Figure 6 A) and light brown to yellow ventrally (Figure 6 B), with no white patches devoid of tube feet on the lateral and dorsal surfaces of the body. The two species differ also in terms of distribution: <i>A. caerulea</i> has not yet been found in the Red Sea, whereas <i>A. bannwarthi</i> seems restricted to it. Sloan <i>et al.</i> (1979, as <i>A.</i> sp. cf. <i>A. bannwarthi</i>), Cherbonnier (1988) and Rowe & Gates’ (1995) records of <i>A. bannwarthi</i> need verification. Certainly one of the Malagasy specimens identified by Cherbonnier (1988) is <i>A. mauritiana</i> and not <i>A. bannwarthi.</i></p> <p> With comparative voucher material now at hand, we conclude that we are not dealing with <i>Actinopyga crassa</i> (see Erhardt & Moosleitner 1995). The latter species differs markedly from <i>A. caerulea</i> in the presence of stout, slightly curved rods in the ventral body wall and in the presence of elongated narrow rod­like rosettes with lateral extensions in the dorsal body wall (cf. Panning 1944, fig 19, p. 51).</p> <p> The more recently described <i>A. flammea</i> also appears to belong to Panning’s (1944) ‘ <i>echinites</i> group’, an observation we share with Cherbonnier (1979). Nevertheless, <i>A. caerulea</i> can again be easily distinguished from <i>A. flammea</i>, in life, because <i>A. caerulea</i> has a conspicuous bluish and white colouration, and <i>A. flammea</i> has a uniformly brick red body wall and prominent, greyish, tubercular “papillae”. Further, <i>A. caerulea</i> differs markedly from <i>A. flammea</i> in not having closed rosettes in the ventral body wall (see Cherbonnier 1979, fig. 2F,G, p. 5).</p> <p> Our observation of a compound endplate in the ventral tube feet is not new. This character has already been noted for several species in <i>Actinopyga, Bohadschia</i>, <i>Pearsonothuria graeffei</i> (Semper, 1868), as well as in certain Stichopodidae (Massin 1996; 1999; unpublished data) and Synallactidae, notably species of <i>Synallactes</i> Ludwig, 1894 (Massin, 1992). More detailed systematic study of such “fragmentation” in all the genera of Aspidochirotida will help to determine whether this phenomenon is due to common descent or not. For now, we can note that an endplate of a large diameter (500 m across) does not <i>ipso facto</i> imply that the endplate will be compound. Indeed, some aspidochirotid species have a simple, single endplate of over 500 m across, while others possess a compound endplate that is 350 m across.</p>Published as part of <i>Samyn, Yves, Vandenspiegel, Didier & Massin, Claude, 2006, A new IndoWest Pacific species of Actinopyga (Holothuroidea: Aspidochirotida: Holothuriidae), pp. 53-68 in Zootaxa 1138</i> on pages 58-66, DOI: <a href="http://zenodo.org/record/172021">10.5281/zenodo.172021</a>
Massinium albicans Samyn & Thandar, 2010, sp. nov.
No full textMassinium albicans sp. nov. (figs 5 A–M, 6 A–F, 7) Neothyonidium magnum; Cherbonnier 1980: 656, fig 20 A–Q; Féral & Cherbonnier 1986: 102, fig. 40 T (non N. magnum) Name bearing type: Holotype: MNHN EcHh 3096; 2 paratypes MNHN EcHh 3087. Type locality: Chenal Devarenne, New Caledonia. Material examined: MNHN EcHh 3096 (holotype), Chenal Devarenne (New Caledonia), 15–20 m depth, 1979, coll. Menou; MNHN, EcHh 3087 (2 paratypes), Baie de Canala (New Caledonia), 15–20 m depth, 1979, coll Menou. Diagnosis: Medium-sized, U-shaped species with bloated mid-body with short anterior and long posterior ends. Tables of introvert of two types: those with small ovoid to octagonal disc, perforated by four large and 1–2 small holes alternating with the large ones, and those with more (15–20), small peripheral holes. Introvert tube feet with tables with reduced spire and perforated plates of various shapes and sizes. Etymology: The name albicans refers to the yellow-whitish colouration of the body wall and the introvert. Holotype description: Specimen entire, well-preserved, but calcareous ring detached from introvert due to previous dissection. Body wall firm, rather thick (1–4 mm), slightly rough to the touch. Body form cylindrical, U-shaped, slightly contracted, bloated, with narrow anterior and posterior ends. Introvert well extended, attached to main body. Length of specimen along ventral surface 150 mm; along dorsal surface 75 mm; height of mid-body 50 mm; anterior and posterior ends approximately 35 and 60 mm long; introvert 50 mm long. Colouration of body and introvert yellowish white. Tube feet of body wall yellowish, numerous, small, mostly retracted except on bloated ventral portion, uniformly scattered over entire body, very small suckers. Tube feet of introvert brownish, darker proximally, aligned in radial areas in two well-defined rows, absent in distal 10 mm. Tentacles 20, according to original description, 10 large, 10 small, arranged in two circles; outer tentacles 35–40 mm long, shaft whitish with brownish annulations at base, ramifications blackish; inner tentacles arranged in pairs in the radii, uniform white, 5–8 mm long. Anus small, perhaps surrounded by five (only three counted) small, slender, well calcified teeth, each flanked by a group of terminal podia. Calcareous ring (fig. 7) 70 mm long, tubular with radial and interradial plates fused for five sevenths of the length of calcareous ring, radials prolonged and their processes fused posteriorly, fragmentation of calcareous ring not obvious due to encapsulating thick membrane. Polian vesicles four, three long ones, up to 105 mm (one terminally bifid), and one short, white. Stone canals two, one small, 3.5 mm long, poorly calcified, the other considerably elongated, 15 mm long, and well calcified, both arising together, each inperceptably merging into the madreporite. Introvert retractor muscles thick and short, originating at anterior third of the body. Ossicle assemblage. Body wall deposits, 15–50 Μm long, site dependent: anterior deposits comprise predominantly pseudobuttons and some rosettes (fig. 5 A), mid-body wall deposits additionally comprise elongated pseudobuttons with few holes (fig. 5 B, 6 A&B), posterior deposits comprise mostly rosettes (fig. 5 C). Ventral tube feet with irregular perforated plates (fig. 5 D) and small, 15–20 Μm long, pseudobuttons (fig 5 E). Introvert with tables (figs 5 F, 6 C) and very scarce rosettes of only 20–25 Μm long. Tables with round to oval smooth discs, 70–90 Μm long, perforated by four central holes of which two are larger than the alternating two, and numerous smaller holes in 2–3 peripheral circles; spire two-pillared, medium to high, with 1–2 cross-bars, terminating in two or more, often diverging, toothed projections. Tube feet of introvert with rosettes, tables and multilocular plates (figs 5 G–J, 6 D–E). Rosettes simple to complex, 20–40 Μm long, open type, with distal endings mostly swollen (fig. 5 G, 6 D). Multilocular plates of various shapes, 50–150 Μm long, with mostly larger central perforations and no branched ends (fig. 5 J, 6 E). Tables scarce, if present, of introvert type with discs complete, but spire mostly reduced to knobs (fig. 5 H, 6 E). Peristome with complex, elongated rosettes, 30–60 Μm long, with swollen distal endings, often anastamosing (figs 5 K, 6 E). Shaft and tips of large and small tentacles with deposits similar to those of peristome (fig. 5 L). Longitudinal muscles of body wall with rods, rosette-like plates and pseudobuttons. Longitudinal muscles of introvert and of cloacal retractor muscles (fig. 5 N) with rosettes only. Gonoduct with rosettes and lattice-like plates (fig. 5 M). Paratypes description (2 complete specimens). Morphology as in holotype. The ossicle assemblage could not be assessed due to preservation in acidic Bouin’s fluid which dissolved all the calcareous structures. Ecology: According to Féral and Cherbonnier (1986), this species lives buried in sand or mud on the outer slope of the reef. They further report that in high current environments population density is low, whereas in calmer conditions population density is high and that the species is still visible during the day, but more active during the night. Although listed as rare, the authors report its presence around the whole of New Caledonia, at depths of 3– 30 m. Remarks: Cherbonnier (1980) noted that the ossicle assemblage of the introvert of his New Caledonian specimen differs from that described by Sluiter (1901). Cherbonnier (1980) therefore examined the slides prepared by Sluiter and discovered that, in addition to the tables with a small ovoid to octagonal disc, perforated by four large holes and 1–2 small perforations alternating with the large holes, numerous other tables with more (15–20), small peripheral holes were also present in the introvert of his New Caledonian specimen (cf. Cherbonnier 1980: fig. 20 F). Cherbonnier (1980) further noted that the spire of these tables is rather low, ending in four short smooth to spiny points (Cf Cherbonnier 1988: fig. 20 K). However, in Sluiter’s preparations he failed to locate tables that have their disc and spire similar to those he illustrates (cf. Cherbonnier 1980: figs 20 F,J,L,N). He correctly questioned if his, Sluiter’s or Domantay’s (1933) records are the true N. magnum. After examination of the holotype, he concluded that the tables in the introvert of his material correspond best with the holotype. We disagree with Cherbonnier’s (1980) decision because the tables in the New Caledonia material, here described as a new species, have their discs perforated with more holes and show the spires terminating in pronounced tooth-like projections. Moreover, we note there is a marked difference in the plate-like deposits of the introvert tube feet of the of the two species. While those of M. magnum are highly irregular with their terminal ends branched (figs 1 C, 2 C), those of M. albicans are more regular, never with branched terminal ends, and with much more smaller perforations (figs 5 J, 6 F). Moreover, the peristomial deposits in both species vary considerably (cf. figs 1 D, 2 D with figs 5 K, 6 F). Lastly, the colouration of the introvert of M. albicans and M. magnum is markedly different (cf. Massin 1999, fig 113 a with Cherbonnier & Féral 1986: 103). M. albicans is perhaps endemic to New Caledonia.Published as part of Samyn, Yves & Thandar, Ahmed S., 2010, Two new species in the phyllophorid genus Massinium (Echinodermata: Holothuroidea) with redescription of Massinium magnum, pp. 1-19 in Zootaxa 2399 on pages 8-12, DOI: 10.5281/zenodo.19404
Massinium granulosum Samyn & Thandar, 2010, sp. nov.
No full textMassinium granulosum sp. nov. (figs 8 A,B; 9 A–E, 10 A–C, 11 A–F) Name bearing type: Holotype: AMS: J 13578. Type locality: Dunwhich (Stradbroke Island, Moreton Bay, Queensland, Australia) Material examined: AMS J 13578 (holotype + paratype, identified as Neothyonidium magnum by F.W.E. Rowe), Dunwhich (Stradbroke Island, Moreton Bay, Queensland, Australia), intertidal, 14.xi. 1977, coll. H. Silver. Diagnosis: Small-sized, U-shaped species, with slightly bloated mid-body with narrow anterior and posterior ends; body wall deposits granuliform, rarely perforated rods. Etymology: The name granulosum refers to granuliform rods of the body wall. Holotype description: Specimen well-preserved, calcareous ring and associated structures detached, but still linked to main body by introvert. Body wall firm, but not thick (2–3 mm), slightly rough to the touch. Body form cylindrical, U-shaped, slightly twisted, slightly bloated mid-ventrally with narrower anterior and posterior ends. Length along ventral surface 130 mm; length along dorsal surface 90 mm; height of mid-body about 30 mm; anterior and posterior ends respectively 15 and 10 mm long; introvert approximately 25 mm long. Anterior and posterior body wall with series of slits in interradial areas. Colouration of body yellowish white, slightly paler mid-ventrally; introvert yellowish white. Tube feet of body wall retracted, numerous, small, scattered over entire body, suckers minute, beige. Tube feet of introvert scarce, restricted to the most proximal part, in the radii, in one to two rows. Tentacles 20, in two circles, outer circle of 10 large (only seven intact), inner circle of 10 small alternating in pairs with large ones; outer tentacles 25–40 mm long, shaft yellowish brown without visible annulations, ramifications dark brown; inner tentacles about 5 mm long, colour as in large tentacles. Anus small, surrounded by five minute teeth, quite deciduous, each flanked by several brownish papillae situated in distinct triangular dispositions. Calcareous ring (Fig. 8 A) 40 mm long, tubular, with radial and interradial plates fused for three quarters of length of calcareous ring, radials posteriorly prolonged, bifurcating, with processes fused to those of neighbouring plates; radial plates with deep anterior notch; interradial plates anteriorly pointed; fragmentation of calcareous ring not obvious due to thick encapsulating membrane. Polian vesicles four, one sacciform, three tubular, elongated, up to 35 mm long, with tip of one of the latter, deformed and lying in a posterior slit of calacareous ring (fig. 8 A & B). Stone canal single, poorly calcified, about 9 mm long, merging inperceptably into ovoid madreporite. Introvert retractor muscles thin and short, originating from anterior end of longitudinal muscles. Ossicle assemblage. Dorsal and ventral body wall deposits identical, comprising irregular pseudobuttons and granuliform, rarely perforated rods of various shapes, 25–105 Μm long (figs 9 A,B; 11 A,B). Introvert with tables only; table disc ovoid, smooth, perforated by four large central holes and smaller holes alternating with these, in 1–2 peripheral circles; spire two-pillared, medium height, 50–75 Μm high and 35–50 Μm wide, with single cross-bar, terminating in 2–4 toothed projections (fig. 9 C, 11 C). Tube feet of introvert with endplate surrounded by slender and plate-like perforated rods (fig 9 D). Peristome with elongated rosette-like rods, 30– 50 Μm long, and other elongated rods, swollen terminally and perforated, 70–110 Μm long (fig. 9 E, 11 D). Large tentacles devoid of ossicles. Shafts and tips of small tentacles with complex, closed rosettes only (fig. 11 E). Longitudinal muscles of body wall with pseudobuttons and elongated granuliform rods, 22–50 Μm long (fig. 10 A). Anal papillae with elongated slightly curved rods, terminally expanded and perforated, 45–90 Μm long (fig. 10 C, 11 F), and few closed rosettes, 15–35 Μm long (fig. 10 C). Cloacal retractor muscles with pseudobuttons (fig. 10 B). Remarks. Thandar (1989) described the South African endemic Massinium arthroprocessum (Thandar, 1989) from False Bay and in 1996 recorded the species also from Durban. In his publication, Thandar (1989: 643) stated that Rowe advised him that ‘an undescribed, similar but not identical form occurs in Queensland (Australia)”. Upon re-examination of Australian voucher material, identified as Neothyonidium magnum by Rowe, we came across the species Rowe probably implied. It is this species that is here described as new and is clearly sister to the South African form by the presence of characteristic slits in the body wall and simple body wall deposits. However, the South African M. arthroprocessum and the Australian M. granulosum differ clearly from each other in the following four characteristics: (i) body wall colouration in alcohol of M. arthroprocessum is grey speckled with reddish brown, whereas that of M. granulosum is uniform yellowishwhite; (ii) the body wall ossicles are mostly U shaped rods with terminal perforations in M. arthroprocessum, whereas they are more granuliform, seldom perforated and of greater variety in M. granulosum; (iii) tentacle deposits in M. arthroprocessum comprise slender elongated rods bearing a single perforation at each ending, whereas in M. granulosum only rosettes are present and then only in the small tentacles; (iv) introvert deposits of M. arthroprocessum comprise tables, rods and rosettes, whereas those of M. granulosum tables only.Published as part of Samyn, Yves & Thandar, Ahmed S., 2010, Two new species in the phyllophorid genus Massinium (Echinodermata: Holothuroidea) with redescription of Massinium magnum, pp. 1-19 in Zootaxa 2399 on pages 13-17, DOI: 10.5281/zenodo.19404
Monitoring Variations in Thermal Curing of Nanoparticle Coatings through Confocal Raman Microscopy and Principal Component Analysis
No full textFor paper coatings with organic nanoparticles of poly(styrene-co-maleimide), dispersive Raman spectroscopy and confocal Raman microscopy are applied for qualitative and quantitative analyses of the lateral distribution of chemical moieties as a function of different coating grades (degree of imidization) and thermal curing temperatures (120-250 degrees C). Raman mapping with band intensity ratios, single band intensities, and average spectral intensities illustrates that surface locations with imide moieties are sensitive to the thermal curing temperature due to the reactivity of an amount of ammonolyzed (nonimidized) maleic anhydride, whereas the styrene moieties are not sensitive to the thermal curing. A maximum in imide functionalities at the surface occurs after curing at 135-150 degrees C depending on the coating grade. The surface coverage of the coating moieties is complementary to the cellulose components, but local variations in specific Raman bands for the latter suggest interactions due to hydrogen bonding. Principal component analysis with two parameters allows for a good quantification of the imide content and surface coverage.Samyn, P (reprint author), Univ Hasselt, Inst Mat Res IMO IMOMEC, Appl & Analyt Chem, Agoralaan Gebouw D, B-3590 Diepenbeek, Belgium.
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MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Figure 1. A–D in Taxonomy of the heavily exploited Indo-Pacific sandfish complex (Echinodermata: Holothuriidae)
No full textFigure 1. A–D, Holothuria (Metriatyla) lessoni sp. nov. A, holotype (the covering fine layer of sand was gently brushed away); B, holotype (top) and paratype (bottom); C, black form (IG 30768/5); D, mottled form (IG 30768/4). E, H. timama Lesson, 1830, original drawing; F, H. timama Lesson, 1830, remaining fragment of holotype. Photographs A & B by C. Massin, C & D by S. Purcell; E & F by Y. Samyn.Published as part of Massin, Claude, Uthicke, Sven, Purcell, Steven W., Rowe, Frank W. E. & Samyn, Yves, 2009, Taxonomy of the heavily exploited Indo-Pacific sandfish complex (Echinodermata: Holothuriidae), pp. 40-59 in Zoological Journal of the Linnean Society 155 (1) on page 42, DOI: 10.1111/j.1096-3642.2008.00430.x, http://zenodo.org/record/544575
Bathyplotes natans Sars 1868
No full textBathyplotes natans (Sars, 1868) (Fig. 16 A – D) Holothuria natans Sars, 1868: 20. Bathyplotes natans; Rowe & Gates, 1995: 328 (synonymy); Pawson et al., 2009: 1202. Material examined. Non-type material: IE-2007-772 (1 specimen, collected between Majunga and Cape Saint André) Remarks. C-shaped rods have been reported from the body wall of several Bathyplotes species. As already noted by Östergren (1896), C-shaped ossicles are absent in the body wall of B. natans; they are however present in the cloacal wall and in the longitudinal muscles, the latter being a new observation (fig. 12D). This record is however the first for the Indian Ocean.Published as part of Samyn, Yves & Vandenspiegel, Didier, 2016, Sublittoral and bathyal sea cucumbers (Echinodermata: Holothuroidea) from the Northern Mozambique Channel with description of six new species, pp. 451-497 in Zootaxa 4196 (4) on page 474, DOI: 10.11646/zootaxa.4196.4.1, http://zenodo.org/record/16827
Self-assembly of microsystem components with micrometer gluing pads through capillary forces
No full textThe self-alignment of microparts based on capillary forces and micrometer adhesive pads was evaluated through experimental evidence, analytical modelling and simulation. The local deposition of adhesive pads in the range of 2000 to 20 mu m was realized by photo-lithographical patterning of an acrylate adhesive interlayer, followed by the spontaneous assembly with glass counterfaces that have a complementary array of hydrophobically modified gold structures. The design rules for self-alignment of microparts were studied from calculations of the capillary force and displacement as a function of the adhesive pad dimensions, pad heights and offset length. In all cases, the self-alignment induced by capillary forces is driven by a minimization of the surface energy, leading to an equilibrium position. The analytical results provided good qualitative understanding of the alignment process: larger dimensions, smaller separation and higher offset values contributed to higher forces and fast alignment. The simulation experiments in Surface Evolver were based on calculated geometries of adhesive pad providing a minimum surface energy and also take into account the local deformation of the adhesive pad together with an additional degree of rotational freedom. Consequently, the latter results indicated a high degree of precision with good correlation to the experiments and analytical results.Samyn, P (reprint author), Hasselt Univ, Inst Mat Res Appl & Analyt Chem, Agoralaan Gebouw D, B-3590 Diepenbeek, Belgium.
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Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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