Search results for "analysis."
showing 10 items of 26008 documents
Resistance of seagrass habitats to ocean acidification via altered interactions in a tri-trophic chain
2020
Despite the wide knowledge about prevalent effects of ocean acidification on single species, the consequences on species interactions that may promote or prevent habitat shifts are still poorly understood. Using natural CO2 vents, we investigated changes in a key tri-trophic chain embedded within all its natural complexity in seagrass systems. We found that seagrass habitats remain stable at vents despite the changes in their tri-trophic components. Under high pCO2, the feeding of a key herbivore (sea urchin) on a less palatable seagrass and its associated epiphytes decreased, whereas the feeding on higher-palatable green algae increased. We also observed a doubled density of a predatory wr…
A Network Model for the Correlation between Epistasis and Genomic Complexity
2008
The study of genetic interactions (epistasis) is central to the understanding of genome organization and evolution. A general correlation between epistasis and genomic complexity has been recently shown, such that in simpler genomes epistasis is antagonistic on average (mutational effects tend to cancel each other out), whereas a transition towards synergistic epistasis occurs in more complex genomes (mutational effects strengthen each other). Here, we use a simple network model to identify basic features explaining this correlation. We show that, in small networks with multifunctional nodes, lack of redundancy, and absence of alternative pathways, epistasis is antagonistic on average. In c…
Variational Approximations for Generalized Linear Latent Variable Models
2017
Generalized linear latent variable models (GLLVMs) are a powerful class of models for understanding the relationships among multiple, correlated responses. Estimation, however, presents a major challenge, as the marginal likelihood does not possess a closed form for nonnormal responses. We propose a variational approximation (VA) method for estimating GLLVMs. For the common cases of binary, ordinal, and overdispersed count data, we derive fully closed-form approximations to the marginal log-likelihood function in each case. Compared to other methods such as the expectation-maximization algorithm, estimation using VA is fast and straightforward to implement. Predictions of the latent variabl…
Can vegetation provide indications of ancient lake shorelines after more than one hundred years? A case study of Iskander-kul Lake, Tajikistan
2017
Abstract Bioindication is a common approach to assess and evaluate environmental changes over both short or long periods of time. Here we attempt to highlight that vegetation can provide indications of the palaeoshoreline of Lake Iskander-kul, even after at least 150 years. It is an example of a dammed lake that was created by a huge mass rockfall as a result of a strong earthquake during the late Pleistocene. Applying the two way indicator species analysis (TWINSPAN) we found that the shrubby vegetation is the particular one that can still effectively thrive along the palaeoshoreline despite the lake downlift. Using the phi coefficient as a fidelity measure for certain vegetation type, we …
A new C12 alcohol identified as a sex pheromone and a trail-following pheromone in termites: the diene (Z,Z)-dodeca-3,6-dien-1-ol
2003
0028-1042 (Print) Journal Article; The diunsaturated C12 alcohol (Z,Z)-dodeca-3,6-dien-1-ol (dodecadienol) has been characterized by GC-MS and FTIR as a novel releaser pheromone in termites. This alcohol identified in Ancistrotermes pakistanicus (Termitidae, Macrotermitinae) possesses a double pheromonal function which again illustrates the chemical parsimony of termites compared with other social insects. In workers, dodecadienol elicits trail-following at a very low concentration (activity threshold at 0.1 pg/cm of trail); in male alates it induces trail-following at a low concentration (1-10 pg/cm) and sexual attraction at a higher concentration (about 1 ng). Traces of the monounsaturate…
New Acyclic Cytotoxic Jasplakinolide Derivative from the Marine Sponge Jaspis splendens
2019
A new acylic jasplakinolide congener (2), another acyclic derivative requiring revision (4), together with two jasplakinolide derivatives including the parent compound jasplakinolide (1) were isolated from the Indonesian marine sponge Jaspis splendens. The chemical structures of the new and known compounds were unambiguously elucidated based on HRESIMS and exhaustive 1D and 2D NMR spectral analysis as well as a comparison of their NMR data with those of jasplakinolide (1). The isolated jasplakinolides inhibited the growth of mouse lymphoma (L5178Y) cells in vitro with IC50 values in the low micromolar to nanomolar range.
The WtmsDW Locus on Wheat Chromosome 2B Controls Major Natural Variation for Floret Sterility Responses to Heat Stress at Booting Stage
2021
Heat stress at booting stage causes significant losses to floret fertility (grain set) and hence yield in wheat (Triticum aestivum L.); however, there is a lack of well-characterized sources of tolerance to this type of stress. Here, we describe the genetic analysis of booting stage heat tolerance in a cross between the Australian cultivars Drysdale (intolerant) and Waagan (tolerant), leading to the definition of a major-effect tolerance locus on the short arm of chromosome 2B, Wheat thermosensitive male sterile Drysdale/Waagan (WtmsDW). WtmsDW offsets between 44 and 65% of the losses in grain set due to heat, suggesting that it offers significant value for marker-assisted tolerance breedin…
Anti-Transpirant effects on vine physiology, berry and wine composition of cv. Aglianico (Vitis vinifera L.) grown in South Italy
2019
In viticulture, global warming requires reconsideration of current production models. At the base of this need there are some emerging phenomena: modification of phenological phases
Influence of composition on mechanical properties of strawberry gels. Compression test and texture profile analysis / Influencia de la composición de…
1999
Fruit gels were prepared containing four levels (20, 40, 60 and 80%) of strawberry pulp, four levels (0.5, 0.7, 0.9 and 1.1 %) of hydrocolloids (kappa-carrageenan plus locust bean gum, 1:1) and two levels (0, 10%) of sucrose. Their mechanical properties were analyzed by compression (failure stress and failure strain) and by texture profile analysis, TPA (hardness, cohesiveness, springiness, adhesive ness, and chewiness). Addition of hydrocolloids produced expected increases in both stress and strain at failure. Sucrose increased failure stress but did not alter strain values. Increasing the pulp content from 20 to 80% resulted in a slight increase in stress and clearly lowered strain at fa…
Recuperación post-nihilista de la intimidad corporal y la persona humana a partir de Nietzsche y Conill
2020
El objetivo de este trabajo es poner en relación el núcleo crítico de la última obra de Je-sús Conill, Intimidad corporal y persona huma-na. De Nietzsche a Ortega y Zubiri1, con la pro-blemática del nihilismo, como estructura que pervive en nuestras sociedades contemporáneas, en especial, en el contexto de las neurociencias, la tecnología y nuestro modo de relación con am-bas. Tras bosquejar a modo de presentación las idea clave del libro, en especial su innovadora con-cepción de la intimidad corporal, recuperaré al-gunas aportaciones de la tematización nietzsche-ana del nihilismo, para mostrar, en tercer lugar, que tras la "muerte de Dios" otras instancias toman su lugar, y que las lógicas…