Morphological character evolution of Amorphophallus (Araceae) based on a combined phylogenetic analysis of trnL, rbcL, and LEAFY second intron sequences

Sequences of three different genes in 69 taxa of Amorphophallus were combined to reconstruct the molecular phylogeny of this species-rich Aroid genus. The data set was analyzed by three different methods, Maximum Parsimony, Maximum Likelihood and Bayesian analysis, producing slightly different tree topologies. Three major clades identified in all analyses reflect the biogeographical distribution of Amorphophallus. Some clades were supported by morphological characters such as sessile/nonsessile stigma, pollen opening mechanism, shape of the main segments of the lamina, growth cycle, and berry colour. When optimised, a nonsessile stigma may have evolved from a sessile one with several reversals. Pollen opening by connective rupturing evolved from pollen opening by pores. Unequally shaped segments of the lamina evolved from equally shaped segments. Simultaneously existing leaf and inflorescences evolved from alternating leaves and inflorescences. Blue, purple, green, and yellow berries evolved from red/orange/white ones

Molecular Profiling of Gliomas

Gliomas are the most common type of primary brain tumors in adults with an incidence rate of 5.27 per 100.000 patients every year 1-2. In 1926, Bailey and Cushing suggested a classification model based on distinct histological morphologies 3, which forms the basis of the currently used WHO classification 1. Two major subtypes are recognized: Astrocytic (A) and oligodendrocytic (OD) tumors, the latter including pure OD tumors and mixed oligoastrocytic (MOA) tumors. Astrocytic tumors are further separated into grades I (pilocytic astrocytomas [PA]), II (low grade), III (anaplastic), and IV (glioblastoma [GBM]). Oligodendrocytic tumors are further separated into grades II (low grade) and III (anaplastic). Patient survival, time to tumor progression, and response to therapy are all associated with subtype and grade of the tumor 1. This classification model, combined with the patients’ prognostic features (e.g. age and Karnofsky Performance Score [KPS]), guides treatment decisions

Imaging dielectric relaxation in nanostructured polymers by frequency modulation electrostatic force microscopy

We have developed a method for imaging the temperature-frequency dependence of the dynamics of nanostructured polymer films with spatial resolution. This method provides images with dielectric compositional contrast well decoupled from topography. Using frequency-modulation electrostatic-force-microscopy, we probe the local frequency-dependent (0.1–100 Hz) dielectric response through measurement of the amplitude and phase of the force gradient in response to an oscillating applied electric field. When the phase is imaged at fixed frequency, it reveals the spatial variation in dielectric losses, i.e., the spatial variation in molecular/dipolar dynamics, with 40 nm lateral resolution. This is demonstrated by using as a model system; a phase separated polystyrene/polyvinyl-acetate (PVAc) blend. We show that nanoscale dynamic domains of PVAc are clearly identifiable in phase images as those which light-up in a band of temperature, reflecting the variations in the molecular/dipolar dynamics approaching the glass transition temperature of PVAc

A new Specklinia (Orchidaceae: Pleurothallidinae) from Costa Rica and Panama

A new species of Specklinia from the Cordillera de Talamanca in southern Costa Rica and western Panama is described and illustrated. Specklinia absurda most closely resembles Specklinia fuegi. It differs from that species in the pendent, single flowered inflorescence, whitish yellow sepals with red-pink veins and yellow apex, red petals with translucent margins, pandurate-trilobed, unguiculate lip with a distinct papillose isthmus below the anterior lobe, and reniform, erose, erect lateral lobes, with a Y-shaped thickened, hirsutulous apical callus. The affinities of this species to other Specklinia species are discussed.Se describe e ilustra una nueva especie de Specklinia de la Cordillera de Talamanca en el sur de Costa Rica y el oeste de Panamá. Specklinia absurda es similar a Specklinia fuegi, sin embargo se diferencia principalmente en la inflorescencia pendulosa de una sola flor, las flores con los sépalos blanco-amarillentos con venas roja-rosadas, el ápice amarillo, los pétalos de color rojo con bordes translúcidos y el labelo pandurado-trilobulado, unguiculado, con un istmo conspicuamente papiloso detrás del lóbulo anterior, los lóbulos laterales reniformes, erosos, erectos en posición natural, con un callo apical, engrosado, hirsutuloso en forma de Y. Se discuten las afinidades de esta especie dentro de Specklinia.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL

Sepal identity of the pappus and floral organ development in the common dandelion (<i>Taraxacum officinale</i>; Asteraceae)

Contains fulltext : 237388.pdf (Publisher’s version ) (Open Access

Possible chemical mimicry of the European lady’s slipper orchid (Cypripedium calceolus)

Pollination based on insect deception has been debated in the scientific community since it was first reported over two hundred years ago. A vast majority of deceptive syndromes occur within the orchid family. While many cheating flowers have been described and are well known, there are still many curious cases that need further investigation. One prime example of such a case is Cypripedium calceolus, known as European lady’s slipper orchid. While the flower has been of interest to many prominent scientists for over a century, its pollination is still not fully understood. Both visual and olfactory cues seem to play an important role in pollinator attraction. In this study we focussed on the olfactory cues in order to explore their relationship (in future experiments) with floral visual cues, including the unique asymmetry of these flowers. Some of the plants’ floral fragrances were used in Electroantennography experiments. Eleven chemical compounds were applied to the antennae of Bombus terrestris and Apis mellifera. Even though these species are not regular visitors of C. calceolus, we were interested to see whether there were common principles in their responses to the flowers’ scent that might justify extrapolating to other pollinator species such as sand bees that get trapped in these orchids and fly out of the flowers afterwards with pollen smeared on their body. The results show that while both species react similarly to most of the odours, some of the tested acetates induced a significantly greater reaction in B. terrestris antennae. These acetates play an important role in bumblebee pheromones, but their relevance for the natural pollinators of C. calceolus remains to be confirmed to see whether chemical mimicry by these flowers is deliberately employed to attract pollinators

Traps as treats: a traditional sticky rice snack persisting in rapidly changing Asian kitchens

Background: An accessory to modern developing economies includes a shift from traditional, laborious lifestyles and cuisine to more sedentary careers, recreation and convenience-based foodstuffs. Similar changes in the developed western world have led to harmful health consequences. Minimization of this effect in current transitional cultures could be met by placing value on the maintenance of heritage-rich food. Vitally important to this is the preservation and dissemination of knowledge of these traditional foods. Here, we investigate the history and functionality of a traditional rice snack cooked in Nepenthes pitchers, one of the most iconic and recognizable plants in the rapidly growing economic environment of Southeast Asia. Methods: Social media was combined with traditional ethnobotanical surveys to conduct investigations throughout Malaysian Borneo. Interviews were conducted with 25 market customers, vendors and participants from various ethnical groups with an in-depth knowledge of glutinous rice cooked in pitcher plants. The acidity of pitcher fluid was measured during experimental cooking to analyze possible chemical avenues that might contribute to rice stickiness. Results: Participants identifying the snack were almost all (96%) from indigenous Bidayuh or Kadazandusun tribal decent. They prepare glutinous rice inside pitcher traps for tradition, vessel functionality and because they thought it added fragrance and taste to the rice. The pH and chemical activity of traps analyzed suggest there is no corresponding effect on rice consistency. Harvest of pitchers does not appear to decrease the number of plants in local populations. Conclusions: The tradition of cooking glutinous rice snacks in pitcher plants, or peruik kera in Malay, likely carries from a time when cooking vessels were more limited, and persists only faintly in tribal culture today because of value placed on maintaining cultural heritage. Social media proved a valuable tool in our research for locating research areas and in interviewing respondents, and we endorse its further use in ethnobotanical investigations. Our gathered data urges for the preservation of sustainable, tribal plant use for the prosperity of both health and cultur

The glandulous Specklinia: morphological convergence versus phylogenetic divergence

The present paper focuses on the systematics of the Specklinia glandulosa species complex. Traditionally, S. glandulosa has been considered a widely distributed and variable species, ranging from Mexico to the guiana Shield. Here it is treated as one of at least six different, albeit closely related, species. of these species, S. pertenuis and S. vittariifolia, are recognized as distinct species and removed from the synonymy of S. glandulosa, and S. alajuelensis and S. gersonii are described and il- lustrated as new to science. Specklinia chontalensis is described and illustrated from living, Costa rican material. Specklinia alajuelensis is compared with S. glandulosa and S. vittariifolia, from which it differs in its broader leaves, multi-flowered, lax inflorescence that surpasses the leaves, and smaller petals and sepals. Specklinia gersonii is compared with S. glandu- losa, from which it differs in the smaller leaves, and the smaller, orange flowers.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL

Gene expression profiles of gliomas in formalin-fixed paraffin-embedded material

BACKGROUND: We have recently demonstrated that expression profiling is a more accurate and objective method to classify gliomas than histology. Similar to most expression profiling studies, our experiments were performed using fresh frozen (FF) glioma samples whereas most archival samples are fixed in formalin and embedded in paraffin (FFPE). Identification of the same, expression-based intrinsic subtypes in FFPE-stored samples would enable validation of the prognostic value of these subtypes on these archival samples. In this study, we have therefore determined whether the intrinsic subtypes identified using FF material can be reproduced in FFPE-stored samples. METHODS: We have performed expression profiling on 55 paired FF-FFPE glioma samples using HU133 plus 2.0 arrays (FF) and Exon 1.0 ST arrays (FFPE). The median time in paraffin of the FFPE samples was 14.1 years (range 6.6-26.4 years). RESULTS: In general, the correlation between FF and FFPE expression in a single sample was poor. We then selected the most variable probe sets per gene (n = 17 583), and of these, the 5000 most variable probe sets on FFPE expression profiles. This unsupervised selection resulted in a better concordance (R-2 = 0.54) between expression of FF and FFPE samples. Importantly, this probe set selection resulted in a correct assignment of 87% of FFPE samples into one of seven intrinsic subtypes identified using FF samples. Assignment to the same molecular cluster as the paired FF tissue was not correlated to time in paraffin. CONCLUSION: We are the first to examine a large cohort of paired FF and FFPE samples. We show that expression data from FFPE material can be used to assign samples to intrinsic molecular subtypes identified using FF material. This assignment allows the use of archival material, including material derived from large-randomised clinical trials, to determine the predictive and/or prognostic value of 'intrinsic glioma subtypes' on Exon arrays. This would enable clinicians to provide patients with an objective and accurate diagnosis and prognosis, and a personalised treatment strategy. British Journal of Cancer (2012) 106, 538-545. doi: 10.1038/bjc.2011.547 www.bjcancer.com Published online 20 December 2011 (C) 2012 Cancer Research U

Specklinia lugduno-batavae (Pleurothallidinae: Orchidaceae), a new species in the S-digitalis group

Specklinia lugduno-batavae from the Caribbean lowlands of Nicaragua and Costa Rica is formally described and illustrated. The new species belongs to the Specklinia digitalis group and can be recognised by the creeping habit, purple spotted abaxial surface of the leaf and the almost immaculate whitish cream flowers, which are produced in succession on a very short, flexuous inflorescence. The name honours Leiden University and the Hortus botanicus Leiden. The novelty is compared with its closest relatives, Specklinia digitalis, S. pisinna and S. succulenta.Plant science