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51.
Leonel Lopez-Toledo Yazmin Portillo-Cruz María T. Pulido Bryan A. Endress 《Plant Ecology》2013,214(9):1115-1125
Seed dynamics are an important part of the life history of plants and may have strong implications on abundance and spatial distribution of populations. In this study, we explored how seed dynamics (removal, predation, germination) interact with micro-environmental conditions to affect the spatial structure of populations of Brahea aculeata (Arecaceae) in a tropical dry forest. B. aculeata is distributed throughout arroyo basins and attains its highest densities near to arroyos/rivers. We hypothesized that: (i) seed removal, predation and germination vary across topographic positions resulting in greater palm abundances adjacent to arroyos and (ii) seed removers/predators respond to both a seed density-dependent effect and a microclimate effect. To test this, in six arroyos basins, seeds were sown across three topographic positions (stream, mid and top of basins) with two seed abundances (1 and 10), protected and non-protected from potential predators. Predation, removal and germination were then followed. After 107 days, 100 % of the exposed seeds were removed/predated and none germinated. For seed removal, we found differences among topographic positions and seed densities with higher removal (up to 80 %) and lower predation rates for grouped seeds. Germination was only observed for protected seeds with higher germination rates in single (17 % ± 9) than in grouped seeds (4 % ± 1). The highest germination and establishment rates were adjacent to the streams; areas which had the lowest light intensity (mean ± SE = 883 ± 160 lm/ft2) and temperatures (mean ± SE = 20.1 ± 0.6 °C), and highest humidity (mean ± SE = 50.8 ± 1.8 %), especially during the rainy season. Differential seedling establishment rates across the landscape due to spatial patterns of seed predation/removal as well as micro-environmental variables appear to have implications for shaping the spatial structure of B. aculeata population at Sierra de Álamos, Mexico. 相似文献
52.
N. del Hoyo J. A. Pulido M. T. Carretero M. A. Pérez-Albarsanz 《Bioscience reports》1990,10(1):105-112
Rat ventral prostate incorporated (1-14C)acetate, (1-14C)palmitate and (1-14C)linoleate into different phospholipids in a time-dependent process. The rate of incorporation into total phospholipids was higher with linoleate (10.0 nmol/g) than with either palmitate (5.8 nmol/g) or acetate (4.7 nmol/g). Predominant labelling with all the radioactive substrates assayed was found in choline glycerophospholipids (PC). The radioactive profiles for linoleate in the other ventral prostate phospholipids differed from those obtained with palmitate and acetate. Specifically linoleate was incorporated into inositol glycerophospholipids plus lysoethanolamine glycerophospholipids (PI+LPE) and not into sphingomyelin (SM), while palmitate and acetate incorporated into SM but not into PI+LPE. Acetate showed the highest oxidation to CO2 whereas no differences were observed in the radioactivity incorporated into CO2 from a saturated (palmitate) or an essential unsaturated fatty acid (linoleate). These studies also show zinc-dependence by the acetate to CO2 oxidation.Abbreviations PL
total phospholipids
- PC
choline glycerophospholipids
- PE
ethanolamine glycerophospholipids
- PI+LPE
inositol glycerophospholipids plus lysoethanolamine glycerophospholipids
- PS
serine glycerophospholipids
- SM
sphingomyelin 相似文献
53.
54.
Jesse Pulido Maria de Cabrera Adam J. Sobczak Alejandro Amor-Coarasa Anthony J. McGoron Stanislaw F. Wnuk 《Bioorganic & medicinal chemistry》2018,26(21):5624-5630
The conjugation of 4-N-(3-aminopropanyl)-2′-deoxy-2′,2′-difluorocytidine with 2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (SCN-Bn-NOTA) ligand in 0.1?M Na2CO3 buffer (pH 11) at ambient temperature provided 4-N-alkylgemcitabine-NOTA chelator. Incubation of latter with excess of gallium(III) chloride (GaCl3) (0.6?N AcONa/H2O, pH?=?9.3) over 15?min gave gallium 4-N-alkylgemcitabine-NOTA complex which was characterized by HRMS. Analogous [68Ga]-complexation of 4-N-alkylgemcitabine-NOTA conjugate proceeded with high labeling efficiency (94%–96%) with the radioligand almost exclusively found in the aqueous layer (~95%). The high polarity of the gallium 4-N-alkylgemctiabine-NOTA complex resulted in rapid renal clearance of the 68Ga-labelled radioligand in BALB/c mice. 相似文献
55.
In spite of recent theoretical interest, few field studies have addressed the links between individual behavioral decisions
and population distribution. This work analyzes the foraging behavior of individuals and the spatial distribution of a population
of blue tits (Parus caeruleus) just before the main breeding season, when blue tit foraging was not affected by central-place or flocking behaviors. The
study was carried out in open holm oak Quercus ilex woodlands (dehesas) that are patchy for canopy-foraging birds because of the scattered arrangement of trees. Residence time on each tree was
not correlated either with previous flight time or with prey abundance in trees. Flight distances between trees were larger
than average distances estimated in random samples of holm oaks taken close to foraging birds. Trees were not selected by
birds on the basis of their expected energy costs and rewards. Bird abundance was not related to food availability in trees
or to tree size across dehesas. However, bird abundance was strongly correlated with tree density and with the availability of tree holes for nesting, to
the extent that the proportion of tits matched the proportions of both tree abundance and hole abundance across study plots.
Overall, neither the behavior of individuals nor the distribution of the population of blue tits corresponded with food resources,
which appeared superabundant; instead, tits appeared to behave and be distributed according to the distribution of structural
resources such as trees and tree holes for nesting.
Received: 18 August 1996 / Accepted: 14 March 1997 相似文献
56.
Disruption of the gene C12orf35 leads to increased productivities in recombinant CHO cell lines 下载免费PDF全文
57.
Alejandro Solla Slobodan Milanović Alejandro Gallardo Ana Bueno Tamara Corcobado Yonatan Cáceres David Morcuende Alberto Quesada Gerardo Moreno Fernando Pulido 《Tree Genetics & Genomes》2016,12(6):117
Genetic variability of trees influences the chemical composition of tissues. This determines herbivore impact and, consequently, herbivore performance. We evaluated the independent effects of plant genotype and provenance on the tannin content of holm oak (Quercus ilex) and their consequences for herbivory and performance of gypsy moth (Lymantria dispar) larvae. Oak seedlings of 48 open-pollinated families from six populations were grown in a common garden in central Spain. Half the plants were subjected to defoliation by gypsy moth larvae and the other half were destructively sampled for chemical analysis. Tannin content of leaves did not differ significantly among populations but differed significantly among families. Estimates of heritability (h 2) and quantitative genetic differentiation among populations for tannin content (Q ST) were 0.83 and 0.12, respectively. Defoliation was not related to the tannin content of plants nor to spine and trichome densities of leaves, although positive family–mean associations were observed between defoliation and both seed weight and plant height (P < 0.003). Among the oak populations, differential increase in larval weight gain with defoliation was observed. Leaf tannin content in Q. ilex is genetically controlled but does not influence defoliation or predict performance of the larvae. Different efficiencies of food utilisation depending on the oak genotypes indicate that other plant traits are influencing the feeding patterns and fitness of L. dispar and consequent population dynamics. 相似文献
58.
Paola Pulido‐Santacruz Jason T. Weir 《Evolution; international journal of organic evolution》2016,70(4):860-872
The role of historical factors in driving latitudinal diversity gradients is poorly understood. Here, we used an updated global phylogeny of terrestrial birds to test the role of three key historical factors—speciation, extinction, and dispersal rates—in generating latitudinal diversity gradients for eight major clades. We fit a model that allows speciation, extinction, and dispersal rates to differ, both with latitude and between the New and Old World. Our results consistently support extinction (all clades had lowest extinction where species richness was highest) as a key driver of species richness gradients across each of eight major clades. In contrast, speciation and dispersal rates showed no consistent latitudinal patterns across replicate bird clades, and thus are unlikely to represent general underlying drivers of latitudinal diversity gradients. 相似文献
59.
Pulido Mantas Torcuato Pola Lisa Cerrano Carlo Gambi Maria Cristina Calcinai Barbara 《Hydrobiologia》2022,849(8):1969-1980
Hydrobiologia - Considering the pivotal role played by erosive organisms in the marine habitat and the scanty knowledge of this phenomenon in the Mediterranean Sea, the present study aimed to... 相似文献
60.
Darinskas A Gasparaviciute R Malisauskas M Wilhelm K Kozhevnikov JA Liutkevicius E Pilinkiene A Morozova-Roche LA 《Cellular & molecular biology letters》2007,12(3):422-434
We have shown the fetal liver cell engraftments into multiple tissues of adult healthy mice, achieved without suppressing
the animals’ immune systems. Fetal cells from the livers of male C57Bl/6J Black lineage mice at day 13 to 15 of gestation were injected intravenously into female adult CC57W/MY White mice. The grafting was evaluated by Y-chromosome-specific PCR, cytometric analysis of fluorescently stained donor cells,
and histological analysis. All the methods consistently showed the presence of multiple engraftments randomly distributed
through the various organs of the recipients. After 60 days, the grafts still constituted 0.1 to 2.75% of the tissues. The
grafted cells did not change their appearance in any of the organs except the brain, where they became enlarged. Inflammatory
reactions were not detected in any of the histological preparations. The frequency of engraftments was higher in the liver,
indicating that similarity between the donor and recipient cells facilitates engraftment. The high inherent plasticity of
fetal liver cells underlies their ability to integrate into healthy recipient organs, which can be governed by environmental
conditions and connections with neighboring cells rather than by the initial cellular developmental programs. The fact that
fetal liver cells can be grafted into multiple tissues of healthy animals indicates that they can be used to replace the natural
loss of cells in adult organisms. 相似文献