Biology subjects

dos Anjos, L.

Publications and source records attributed to dos Anjos, L..

5 recordsLinked to original sources

bioRxiv2021

Population modelling insights of extinct environments: the case of the Kem Kem palaeocommunity

The Kem Kem beds are well-known palaeontological deposits. Among the species that lived there, there are some large theropods, such as Deltadromeus agilis, Carcharodontosaurus saharicus, and Spinosaurus aegyptiacus. It is possible that these large predators were facultative scavengers, and they could compete for carrion. In the present paper, I simulate a small community module of this environment, consisting of Carrion, Fishes, Spinosaurus, and a functional group composed of large terrestrial Theropods. I assume that these top predators feed on carrion, but they also have exclusive food sources. I show that these exclusive food sources could have assured the possibility of coexistence, and in their absence, one top predator could be locally extinct.

paleontology↗

bioRxiv2021

Intraguild predation does not necessarily have negative effects on pest biological control: insights from a multiple consumer-multiple resource food web population model

We develop a food web population dynamical based on an experimental pest biocontrol setup consisting of thrips and aphids (pests) being consumed by two agents Macrolophus pygmaeus and Orius laevigatus, and with O. laevigatus being an intraguild predator of M. pygmaeus. By means of numerical simulations, we show that pest biocontrol disruption can be avoided depending on initial population densities of pests and agents, despite the intraguild predation (IGP) of O. laevigatus upon M. pygmaeus. This possible avoidance of pest biocontrol disruption is in accordance with the referred experimental setup and moreover, the proposed model corroborates the importance of initial densities of pests and agents in the determination of the failure or success of pest biocontrol found in this and other biocontrol experimental setups.

ecology↗

bioRxiv2021

Multiple stage hydra effect in a stage-structured prey-predator model

In this work, we show by means of numerical bifurcation that two alternative stable states exhibit a hydra effect in a continuous-time stage-structured predator-prey model. We denote this behavior as a stage multiple hydra effect. This concomitant effect can have significant implications in population dynamics as well as in population management.

ecology↗

bioRxiv2021

Distinct metabolic flux modes through the tricarboxylic acid cycle in mesophyll and guard cells revealed by GC-MS-based 13C-positional isotopomer analysis

O_LI13C-Metabolic flux analysis (13C-MFA) have greatly contributed to revealing the regulation of plant metabolism. However, mass spectrometry (MS) approaches have hitherto been limited in their power to deduce flux information due to lack of positional information. C_LIO_LIHere we established an MS-based 13C-positional isotopomer labelling approach and performed a multi-species/cell-types analysis based on previous 13C-MFA to compare flux modes through the tricarboxylic acid (TCA) cycle and associated pathways in mesophyll (MCs) and guard cells (GCs). C_LIO_LIBoth cell types showed high 13C-enrichment in pyruvate. However, GCs and sink MCs, but not source MCs showed high 13C-incorporation into Glu/Gln following provision of 13C-sucrose. Only GCs showed higher 13C-enrichment in the carbon 1 atom of Gln, which is derived from PEPc-mediated CO2 fixation. Increased 13C-enrichment in the carbon 1 of Glu was also observed in both trxo1 and ntra ntrb mutants, but not in wild type Arabidopsis plants, following provision of 13C-glucose. C_LIO_LIOur results suggest that the mitochondrial thioredoxin system restricts the fluxes from PEPc and glycolysis to Glu in illuminated MCs and reveal that fluxes throughout the TCA cycle of GCs resemble those of sink MCs but operate different non-cyclic flux modes to support Gln synthesis in the light. C_LI

plant biology↗

bioRxiv2020

Complex dynamics arising from the interplay between prey harvest saturation and predator-prey dynamics

A study of the influence of prey harvest saturation on the dynamics of a predator-prey system is undertaken. It is shown that the augmentation of the constant intensity harvest part of this functional response can significantly change prey-predator dynamics by means of slight variations of the constant harvest intensity, rendering thus species management difficult due to, for instance, multiple attractors. Given that some management policies rely on the harvest saturation structure studied in this work, these results may have significant implications regarding renewable resource management.

ecology↗