187,729 research outputs found
Micromeria tenensis Puppo & P. Perez 2023, sp. nov.
No full text<i>Micromeria tenensis</i> Puppo & P. Pérez, <i>sp. nov.</i> (Figs. 1–3) <p> Diagnosis:—Differing from <i>M. tragothymus</i> in having more or less pendulous branches (vs. erect); stems tomentose (vs. strigose); leaves ovate, villous or pilose adaxially, densely tomentose abaxially (vs. narrowly lanceolate, revolute, sparsely strigose adaxially, glabrous abaxially but strigose on the midvein); calyx hispid with abundant translucent sessile glands (vs. strigose with few glands), calyx apices triangular to lanceolate, densely white hispid, 0.3–0.7 mm long (vs. subulate to falcate, strigose, 1.5 mm long).</p> <p> Type:— SPAIN. Tenerife: Claros fayal-brezal en Teno Alto, 879 m, UTM 28 R: 0317271-3135723, 05 July 2023, <i>P</i> <i>. Puppo & P.L. <i>Pérez de Paz s.n.</i> (Holotype: TFC 54.826; Isotypes: B; G; K; LPA; MA; ORT; TFC).</i></p> <p>Description:—Subshrub, up to 30 cm high, highly branched; branches persisting and entangled, more or less pendulous, basal part of branches shedding bark, stems tomentose throughout with long, soft, white hairs. Basal leaves opposite and decussate, shortly petiolate, petioles less than 1 mm long, densely tomentose, internodes conspicuous; blades herbaceous 4–6 mm long × 1.5–3 mm wide, ovate, basal ones straight, upper ones somewhat revolute, green sometimes tinged with red or yellow, villous or pilose adaxially, densely tomentose abaxially. Cymes shortly pedunculated arranged on the tip of young branches; peduncles 1–1.5 mm long, densely tomentose; bracts present, 1–1.5 mm long, tomentose. Calyx tubular, green tinged with purple or red, hispid with abundant translucent sessile glands, 2.5–3 mm long, calyx apices triangular to lanceolate, densely white hispid, 0.3–0.7 mm long. Corolla white to lilac, 4–5 mm long, exerted, lower lip projected downwards. Anthers lilac included or barely exerted. Style included or exerted.</p> <p> Phenology:—Like other species of <i>Micromeria</i> on the island, <i>M. tenensis</i> flowers mostly from March to June, rarely throughout the year.</p> <p>Distribution and ecology:—Distributed throughout the Teno massif, from the coastal zone to the highest parts between 100–1000 m elevation growing mostly on shallow, eroded areas.</p> <p>Etymology:—The species epithet refers to its distribution in the massif of Teno.</p> <p>Conservation status:—This new species is locally abundant and has a wide area of distribution in the massif of Teno, so it is considered as LC (Least Concern) according to the categories of the IUCN (2022).</p>Published as part of <i>Puppo, Pamela, Paz, Pedro Luis Pérez De, Curto, Manuel & Meimberg, Harald, 2023, Micromeria tenensis (Lamiaceae), a new species from Tenerife, Canary Islands, pp. 1-7 in Phytotaxa 626 (1)</i> on pages 2-3, DOI: 10.11646/phytotaxa.626.1.1, <a href="http://zenodo.org/record/10148995">http://zenodo.org/record/10148995</a>
Numerical entropy and adaptivity for finite volume schemes
No full textWe propose an a-posteriori error/smoothness indicator for standard semi- discrete finite volume schemes for systems of conservation laws, based on the numerical production of entropy. This idea extends previous work by the first author limited to central finite volume schemes on staggered grids. We prove that the indicator con- verges to zero with the same rate of the error of the underlying numerical scheme on smooth flows under grid refinement. We construct and test an adaptive scheme for systems of equations in which the mesh is driven by the entropy indicator. The adaptive scheme uses a single nonuniform grid with a variable timestep. We show how to implement a second order scheme on such a space-time non uniform grid, preserving accuracy and conservation properties. We also give an example of a p-adaptive strategy
Calceolaria nivalis subsp. lanatifolia Puppo 2023, subsp. nov.
No full text<i>Calceolaria nivalis</i> Kunth subsp. <i>lanatifolia</i> Puppo, <i>subsp. nov.</i> (Fig. 1) <p> <b>Diagnosis:</b> — <i>Calceolaria nivalis</i> subsp. <i>lanatifolia</i> is similar to <i>C. nivalis</i> subsp. <i>cerasifolia</i> but differs from it by having the lower surface of the leaves densely lanate (vs. glabrous) with light yellowish brown trichomes, villous peduncles and pedicels (vs. villous or lanate with ferruginous hairs), sepals with a strigose margin internally (vs. tomentose), and stamens with filaments 0.5 mm long (vs. 1–1.5 mm long).</p> <p> <b>Type:</b> — PERU. La Libertad: Bolívar, Uchumarca, upper slopes of Cerro Filo de Andonsa, 3830 m, 07°06’46’’S, 077°49’29’’W, 31 May 2015, <i>Carlos Vega Ocaña, Rainer W. Bussmann & Narel Paniagua Zambrana 401</i> (Holotype, MO (MO-3147316)!; Isotypes, HAO, MUHW).</p> <p> <b>Paratypes:</b> — PERU. La Libertad: Bolívar, Distr. Uchumarca, curso Las Quinas a Uchumarca, 2300 m, 07°01’46’’S, 077°47’02’’W, 17 May 2011, <i>Narel Paniagua Zambrana, Rainer W. Bussmann, Carlos Vega Ocaña & F. Días Vega 8378</i> (MO!); Distr. Uchumarca, Collpacucho, 3850 m, 07°04’17’’S, 077°48’43’’W, 7 November 2013, <i>Rainer W. Bussmann, Narel Paniagua Zambrana, Carlos Vega Ocaña & Carolina Téllez 17894</i> (MO!).</p> <p> <b>Description:</b> —Erect shrub 0.5–2 m tall; stems glabrous or sparsely villous, purple. Leaves decussate, petiolate; blades coriaceous, lanceolate, 5–8.5 × 1.4–3 cm, attenuate, rounded at base, the margins serrate with mucronulate teeth slightly revolute; upper surface green, glabrous, sparsely villous on the midvein; lower surface reticulate-venose, densely lanate with light yellowish brown trichomes; petioles 6–10 mm long, densely villous. Inflorescence terminal, composed of several cymes; primary peduncles 2.5–3.8 cm long, villous; pedicels 8–18 mm long, villous; cyme bracts present. Sepals entire, ovate, attenuate, 4–5 × 3–4 mm, externally glutinous, internally with a strigose margin. Corolla yellow or bicolor with a patch of long sericeous white hairs near the base of the stamens; upper lip white, pale yellow, or yellow, flattened, 7–10 mm high and 7.5–12 mm wide; lower lip dark yellow, upcurved 10–13 mm, elaiophore present.Anthers pale yellow, glabrous, 2–3 mm long, dehiscent throughout; thecae equal, divaricate; filaments 0.5 mm long. Style 2 mm long. Capsules conical, 5–6 mm long, glutinous.</p> <p> <b>Phenology:</b> —The new subspecies has been recorded flowering and fruiting from May to November.</p> <p> <b>Distribution and ecology:</b> —Only known from Uchumarca district, La Libertad department, Peru, growing on sandstone cliffs or rocky areas between 2300–3850 m elevation.</p> <p> <b>Etymology:</b> —The subspecies epithet refers to the lanate indumentum on the lower surface of the leaves.</p> <p> <b>Conservation status:</b> —Data Deficient – DD (IUCN 2012). Since <i>C. nivalis</i> subsp. <i>lanatifolia</i> is only known from three collections, there is not enough information to accurately assess its conservation status.</p> <p> <b>Taxonomic relationships:</b> — <i>C. nivalis</i> is distributed from central Ecuador to northern Peru between 1700–4200 m elevation. Two subspecies have been recognized in previous taxonomic treatments separated by the Huancabamba deflection (Molau 1979, 1988). <i>Calceolaria nivalis</i> subsp. <i>nivalis</i> occurs north, in Ecuador and in the northernmost part of Peru in the department of Piura. This subspecies is characterized by the pinnate venation of the lower surface of the leaves, and dorsally tomentose petioles. <i>Calceolaria nivalis</i> subsp. <i>cerasifolia</i> Molau (1979: 36) occurs south of the Huancamamba deflection, in northern and central Peru. This subspecies is characterized by the reticulate venation (sometimes pinnate) of the lower surface of the leaves and a denser pubescence on the petioles, ranging from villous to lanate. Other than the pubescence of the petioles, both subspecies have glabrous leaf blades. The new subspecies described here, seems to be an extreme pubescent form of <i>C. nivalis</i>, having the lower surface of the leaves lanate with dense yellowish-brown trichomes, and villous petioles, peduncles, and pedicels. This pubescence in the leaves is so far unique to Sect. <i>Salicifolia</i> (Benth.) Kraenzl. in Engler (1907: 110) (sensu Molau 1988) as species in this section are usually glabrous. Other differences between <i>C. nivalis</i> subsp. <i>lanatifolia</i> and the other two subspecies is that subsp. <i>nivalis</i> and subsp. <i>cerasifolia</i> have sepals with a tomentose margin internally and filaments 1–1.5 mm long while in subsp. <i>lanatifolia</i> the sepals have a strigose margin, and the filaments are 0.5 mm long.</p> <p> <i>Calceolaria nivalis</i> subsp. <i>lanatifolia</i> shares several characteristics with the other two subspecies that justifies the recognition of this taxon as a subspecies of <i>C. nivalis</i>. Namely: leaves lanceolate, serrate, upper lip of the corolla rounded and flattened, lower lip of the corolla saccate and upcurved, and pale yellow, divaricate anthers.</p>Published as part of <i>Puppo, Pamela, 2023, Calceolaria nivalis subsp. lanatifolia, a new subspecies of Calceolariaceae from Northern Peru, pp. 101-105 in Phytotaxa 591 (2)</i> on pages 102-104, DOI: 10.11646/phytotaxa.591.2.2, <a href="http://zenodo.org/record/7797453">http://zenodo.org/record/7797453</a>
Discrete visibility problems and graph algorithms
No full textMany problems of practical interest involve line-of-sight on a topographic surface. Some such problems can be successfully studied on the basis of the mutual visibility among a finite number of representative points. Such visibility problems can be formalized and resolved as graph problems. In this paper, we show that graph algorithms can be useful to find efficient solutions for discrete visibility problems in several cases. On the basis of results from the theory of complexity, we give some practical rules to apply such an approach. We further investigate the solution of some relevant visibility problems under this perspective. © 1997 Taylor & Francis Group, LLC
Montale e le arti figurative
No full textRicostruzione della cultura visiva di Montale, a partire dalle suggestioni pittoriche del periodo ligure, attraverso i contatti con le cerchie artistiche fiorentine negli anni tra le due guerre. Analisi delle principali occorrenze di lemmi «visuali», o di attinenza storico artistica, nell'intera produzione poetica. Ricostruzione dell'attività di Montale come critico d'arte e analisi della sua attività come pittore
Spatial queries on a hierarchical terrain model
No full textIn this paper we consider the problem of defining and answering spatial queries on hierarchical terrain models that provide a multiresolution representation. In particular, we focus our attention on interference queries in which the query object is a spatial entity not belonging to the model. We propose algorithms for efficiently answering such queries on a triangle-based hierarchical model. -Author
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