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Seed dispersal

Devrim Semizer-Cuming, Erik Dahl Kjær, Reiner Finkeldey
Gene flow dynamics of common ash (Fraxinus excelsior L.) is affected by several human activities in Central Europe, including habitat fragmentation, agroforestry expansion, controlled and uncontrolled transfer of reproductive material, and a recently introduced emerging infectious disease, ash dieback, caused by Hymenoscyphus fraxineus. Habitat fragmentation may alter genetic connectivity and effective population size, leading to loss of genetic diversity and increased inbreeding in ash populations. Gene flow from cultivated trees in landscapes close to their native counterparts may also influence the adaptability of future generations...
2017: PloS One
Paulo R Guimarães, Mathias M Pires, Pedro Jordano, Jordi Bascompte, John N Thompson
Ecological interactions have been acknowledged to play a key role in shaping biodiversity. Yet a major challenge for evolutionary biology is to understand the role of ecological interactions in shaping trait evolution when progressing from pairs of interacting species to multispecies interaction networks. Here we introduce an approach that integrates coevolutionary dynamics and network structure. Our results show that non-interacting species can be as important as directly interacting species in shaping coevolution within mutualistic assemblages...
October 18, 2017: Nature
Chelse M Prather, Andrew Huynh, Steven C Pennings
Woody encroachment threatens prairie ecosystems globally, and thus understanding the mechanisms that facilitate woody encroachment is of critical importance. Coastal tallgrass prairies along the Gulf Coast of the US are currently threatened by the spread of several species of woody plants. We studied a coastal tallgrass prairie in Texas, USA, to determine if existing woody structure increased the supply of seeds from woody plants via dispersal by birds. Specifically, we determined if (i) more seedlings of an invasive tree (Tridacia sebifera) are present surrounding a native woody plant (Myrica cerifera); (ii) wooden perches increase the quantity of seeds dispersed to a grassland; and (iii) perches alter the composition of the seed rain seasonally in prairie habitats with differing amounts of native and invasive woody vegetation, both underneath and away from artificial wooden perches...
October 2017: Ecology and Evolution
Ahmed M Meleis, Aria Mahtabfar, Shabbar Danish, Ramsey A Foty
Glioblastoma is highly aggressive. Early dispersal of the primary tumor renders localized therapy ineffective. Recurrence always occurs and leads to patient death. Prior studies have shown that dispersal of Glioblastoma can be significantly reduced by Dexamethasone (Dex), a drug currently used to control brain tumor related edema. However, due to high doses and significant side effects, treatment is tapered and discontinued as soon as edema has resolved. Prior analyses of the dispersal inhibitory effects of Dex were performed on tissue culture plastic, or polystyrene filters seeded with normal human astrocytes, conditions which inherently differ from the parenchymal architecture of neuronal tissue...
2017: PloS One
Carmen Garcia-Jares, Marta Sanchez-Nande, Juan Pablo Lamas, Marta Lores
Camellia (genus of flowering plants of fam. Theaceae) is one of the main crops in Asia, where tea and oil from leaves and seeds have been utilized for thousands of years. This plant is excellently adapted to the climate and soil of Galicia (northwestern Spain) and northern Portugal where it is grown not only as an ornamental plant, but to be evaluated as a source of bioactive compounds. In this work, the main fatty acids were extracted from Camellia seeds of four varieties of Camellia: sasanqua, reticulata, japonica and sinensis, by means of matrix-solid phase dispersion (MSPD), and analyzed by gas chromatography (GC) with MS detection of the corresponding methyl esters...
October 17, 2017: Bioengineering
Yu Liang, Matthew J Duveneck, Eric J Gustafson, Josep M Serra-Diaz, Jonathan R Thompson
Climate change is expected to cause geographic shifts in tree species' ranges, but such shifts may not keep pace with climate changes because seed dispersal distances are often limited and competition-induced changes in community composition can be relatively slow. Disturbances may speed changes in community composition, but the interactions among climate change, disturbance and competitive interactions to produce range shifts are poorly understood. We used a physiologically based mechanistic landscape model to study these interactions in the northeastern United States...
July 28, 2017: Global Change Biology
S C Hess, W J Stark, D Mohn, N Cohrs, S Märsmann, M Calcagni, P Cinelli, J Buschmann
Finding the appropriate cues to trigger the desired differentiation is a challenge in tissue engineering when stem cells are involved. In this regard, three-dimensional environments are often compared to cells' two-dimensional culture behaviour (plastic culture dish). Here, we compared the gene expression pattern of human adipose-derived stem cells (ASC) seeded in a three-dimensional (3D) electrospun mesh and on a two-dimensional (2D) film - both of exactly the same material. Additionally, we conducted experiments with a scaffold floating above a film to investigate two-way paracrine effects (co-system)...
October 13, 2017: European Cells & Materials
Rafał Zwolak
Seed dispersal by animals is a complex phenomenon, characterized by multiple mechanisms and variable outcomes. Most researchers approach this complexity by analysing context-dependency in seed dispersal and investigating extrinsic factors that might influence interactions between plants and seed dispersers. Intrinsic traits of seed dispersers provide an alternative way of making sense of the enormous variation in seed fates. I review causes of intraspecific variability in frugivorous and granivorous animals, discuss their effects on seed dispersal, and outline likely consequences for plant populations and communities...
October 10, 2017: Biological Reviews of the Cambridge Philosophical Society
Jing Ren, Quanfu Xu, Xiaomeng Chen, Wei Li, Kai Guo, Yang Zhao, Qian Wang, Zhitao Zhang, Huisheng Peng, Yi-Gang Li
Cardiac engineering of patches and tissues is a promising option to restore infarcted hearts, by seeding cardiac cells onto scaffolds and nurturing their growth in vitro. However, current patches fail to fully imitate the hierarchically aligned structure in the natural myocardium, the fast electrotonic propagation, and the subsequent synchronized contractions. Here, superaligned carbon-nanotube sheets (SA-CNTs) are explored to culture cardiomyocytes, mimicking the aligned structure and electrical-impulse transmission behavior of the natural myocardium...
October 11, 2017: Advanced Materials
Diego F Cuadros, Anngie Hernandez, Maria F Torres, Diana M Torres, Adam J Branscum, Diego F Rincon
The potato yellow vein disease, caused by the potato yellow vein virus (PYVV), is a limiting potato disease in northern South America. The virus can be transmitted either by the greenhouse whitefly (GWF), Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae), or through vegetative propagules, such as infected tubers. Recently, GWF populations have been spotlighted as one of the main drivers of PYVV re-emergence, and consequently, PYVV management has been predominantly directed toward vector control, which is heavily based on insecticide use...
2017: Frontiers in Plant Science
Brianne Edwards, Liana T Burghardt, Katherine E Kovach, Kathleen Donohue
Variation in the developmental timing in one life stage may ramify within and across generations to disrupt optimal phenology of other life stages. By focusing on a common mechanism of developmental arrest in plants-seed dormancy-we investigated how variation in flowering time influenced seed germination behavior and identified potential processes that can lead to canalized germination behavior despite variation in reproductive timing. We quantified effects of reproductive timing on dormancy cycling by experimentally manipulating the temperature during seed maturation and the seasonal timing of seed dispersal/burial, and by assessing temperature-dependent germination of un-earthed seeds over a seasonal cycle...
September 1, 2017: Integrative and Comparative Biology
L Giménez-Benavides, A Escudero, R García-Camacho, A García-Fernández, J M Iriondo, C Lara-Romero, J Morente-López
Mediterranean mountains are extraordinarily diverse and hold a high proportion of endemic plants but they are particularly vulnerable to climate change and most species distribution models project drastic changes in community composition. Retrospective studies and long-term monitoring also highlight that Mediterranean high-mountain plants are suffering severe range contractions. The aim of this work is to review the current knowledge of climate change impacts on the process of plant regeneration by seed in Mediterranean high-mountain plants, by combining available information from observational and experimental studies...
October 6, 2017: Plant Biology
Casper H A van Leeuwen, Ádám Lovas-Kiss, Maria Ovegård, Andy J Green
In wetland ecosystems, birds and fish are important dispersal vectors for plants and invertebrates, but the consequences of their interactions as vectors are unknown. Darwin suggested that piscivorous birds carry out secondary dispersal of seeds and invertebrates via predation on fish. We tested this hypothesis in the great cormorant (Phalacrocorax carbo L.). Cormorants regurgitate pellets daily, which we collected at seven European locations and examined for intact propagules. One-third of pellets contained at least one intact plant seed, with seeds from 16 families covering a broad range of freshwater, marine and terrestrial habitats...
October 2017: Biology Letters
Erik Francis Acanakwo, Douglas Sheil, Stein R Moe
Seed removal can influence plant community dynamics, composition and resulting vegetation characteristics. In the African savanna, termites and large herbivores influence vegetation in various ways, likely including indirect effects on seed predators and secondary dispersers. However, the intensity and variation of seed removal rates in African savannas has seldom been studied. We experimentally investigated whether termites and large herbivores were important factors in the mechanisms driving observed patterns in tree species composition on and off mounds, in Lake Mburo National Park, Uganda...
October 4, 2017: Ecology
Hafiz Rizwan Sharif, Shabbar Abbas, Hamid Majeed, Waseem Safdar, Muhammad Shamoon, Muhammad Aslam Khan, Muhammad Shoaib, Husnain Raza, Junaid Haider
Preparation of oil-in-water nanoemulsions has emerged as a subject of interest for the encapsulation of lipophilic functional ingredients to increase their stability and activity. In this study, black cumin essential oil nanoemulsions (BCO-NE) using different ratios of essential oil with canola and flax seed oils (ripening inhibitors) were formulated and stabilized with octenyl succinic anhydride (OSA) modified waxy maize starch. The nanoemulsions exhibited monomodal size distributions with mean droplet diameter below 200 nm and zeta potential above -30, indicating a strong electrostatic repulsion between the dispersed oil droplets...
September 2017: Journal of Food Science and Technology
Susan Harrison
No abstract text is available yet for this article.
September 25, 2017: Proceedings of the National Academy of Sciences of the United States of America
L G Pinheiro, K P T Chagas, A S M Freire, M C Ferreira, C G Fajardo, F A Vieira
This study uses ISSR molecular markers to characterize the demographic pattern, and spatial genetic structure (SGS) at different life stages of development (cohorts) in a natural population of Copernicia prunifera in the Rio Grande do Norte State, Brazil. All individuals were sampled and georeferenced in a 0.55-ha plot. The demographic analyses showed a clustered pattern in the first-distance classes and a random or segregated pattern at higher distance classes for all cohorts. Among the three studied life stages, juveniles showed the greatest value for Nei's genetic diversity index (HE = 0...
September 27, 2017: Genetics and Molecular Research: GMR
A B Baldoni, L H O Wadt, T Campos, V S Silva, V C R Azevedo, L R Mata, A A Botin, N O Mendes, F D Tardin, H Tonini, E S S Hoogerheide, A M Sebbenn
Due to the nutritional content and commercial value of its seeds, Bertholletia excelsa is one of the most important species exploited in the Amazon region. The species is hermaphroditic, insect pollinated, and its seeds are dispersed by barochory and animals. Because the fruit set is dependent on natural pollinator activity, gene flow plays a key role in fruit production. However, to date, there have been no studies on pollen and seed flow in natural populations of B. excelsa. Herein, we used microsatellite loci and parentage analysis to investigate the spatial genetic structure (SGS), realized pollen and seed dispersal, and effective pollen dispersal for two B...
September 21, 2017: Genetics and Molecular Research: GMR
Seyed M A Razavi, Fataneh Behrouzian, Ali Alghooneh
The viscoelastic (transient and dynamic) and time-dependent rheological behaviors of XG (xanthan gum), SSG (sage seed gum) and their blends at various ratios (1-3, 1-1, and 3-1 SSG-XG) and temperatures (10, 30, and 50C) were investigated using creep and recovery analyses. The creep compliance was converted to stress relaxation data; then, the structural kinetic model satisfactorily fitted the time-dependent relaxation modulus. Furthermore, dynamic rheology of mixtures was investigated using creep analyses. The most important contribution of the Maxwell spring to deformation (53...
October 2017: Journal of Texture Studies
Florian Jabbour, Myriam Gaudeul, Josie Lambourdière, Guillaume Ramstein, Alexandre Hassanin, Jean-Noël Labat, Corinne Sarthou
The nearly cosmopolitan tribe Desmodieae (Fabaceae) includes many important genera for medicine and forage. However, the phylogenetic relationships among the infratribal groups circumscribed using morphological traits are still poorly known. In this study, we used chloroplast (rbcL, psbA-trnH) and nuclear (ITS-1) DNA sequences to investigate the molecular phylogeny and historical biogeography of Desmodieae, and infer ancestral states for several vegetative and reproductive traits. Three groups, corresponding to the Desmodium, Lespedeza, and Phyllodium groups sensu Ohashi were retrieved in the phylogenetic analyses...
September 28, 2017: Molecular Phylogenetics and Evolution
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