MIER1 (mesoderm induction early response 1 homolog (Xenopus laevis))

Review on MIER1 (mesoderm induction early response 1 homolog (Xenopus laevis)), with data on DNA, on the protein encoded, and where the gene is implicated

Grain-Size Analysis of the Late Pleistocene Sediments in the Corinth Rift: Insights into Strait Influenced Hydrodynamics and Provenance of an Active Rift Basin

Under embargo until: 2023-12-08Grain-size analysis of the sediments in borehole M0079A, which is located in the Corinth Rift, was used to explore hydrodynamic conditions and provenance in the Late Pleistcene Corinth Rift. Grain-size populations that were sensitive to the sedimentary environments were characterized by frequency distribution, particle size-standard deviation, and probability cumulative curves. Our results indicate the grain-size population component in the range 0.15-0.25 μm may be used as a sensitive proxy for hyperpycnal flows, which have commonly been triggered by river floods from the southern margin of the rift since ca. 0.593-0.613 Ma. The high-density plumes derived from the longer rivers of the southern rift that were prevalent before ca. 0.593-0.613 Ma. When sediment is supplied as hemipelagic deposition, the proportion of the total grain-size population that is in the 0.3-0.5 μm range becomes an index for suspension fall-out deposits. The core shows coarser sediments during the marine periods and this may be linked to the current circulation related to the Ishtmia Strait opening. The study thus illustrates how the establishment of interbasinal straits can influence the details of sedimentary hydrodynamics in the deep- water axis of an adjacent depocenter.acceptedVersio

Delayed Differentiation Makes Many Models Compatible with Data for CD8+ T Cell Differentiation

Upon antigen stimulation, naïve CD8+ T cells differentiate into short-lived effectors and longer-lived memory T cells. The kinetics of expansion of antigen-specific CD8+ T cells is highly reproducible at the population level, but the fate of individual naïve cells is stochastic, as individual naïve CD8+ T cells produce different numbers of effector and memory cells. Using mathematical models to analyse experimental data on tracing the fate of individual naïve T cells, it was previously shown that a linear model where naïve CD8+ T cells first differentiate into memory precursors that subsequently differentiate into effector cells describes the data best. However, this ‘memory first’ linear model assumed that the proliferation and differentiation events were distributed exponentially, whereas several studies indicate that differentiation of CD8+ T cell subsets need not follow an exponential distribution. Here we investigate the effect of delayed differentiation by adding intermediate compartments and use similar ordinary differential equations and Gillespie simulations to evaluate alternate models of CD8+ T cell differentiation. Models where a substantial fraction of the naïve CD8+ T cells directly differentiate into effector cells, without going through a memory phase, exhibit population dynamics that are very similar to the original ‘memory first’ linear model. Because alternate models with delayed differentiation perform better than those without a delay, we conclude that non-exponential forms of cellular differentiation need to be considered when comparing models. Hence the exact pathway for the differentiation of naïve CD8+ T cells into effector and memory T cells remains an open question

Pyrethroid resistance in Anopheles gambiae leads to increased susceptibility to the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana

<p>Abstract</p> <p>Background</p> <p>Entomopathogenic fungi are being investigated as a new mosquito control tool because insecticide resistance is preventing successful mosquito control in many countries, and new methods are required that can target insecticide-resistant malaria vectors. Although laboratory studies have previously examined the effects of entomopathogenic fungi against adult mosquitoes, most application methods used cannot be readily deployed in the field. Because the fungi are biological organisms it is important to test potential field application methods that will not adversely affect them. The two objectives of this study were to investigate any differences in fungal susceptibility between an insecticide-resistant and insecticide-susceptible strain of <it>Anopheles gambiae sensu stricto</it>, and to test a potential field application method with respect to the viability and virulence of two fungal species</p> <p>Methods</p> <p>Pieces of white polyester netting were dipped in <it>Metarhizium anisopliae </it>ICIPE-30 or <it>Beauveria bassiana </it>IMI391510 mineral oil suspensions. These were kept at 27 ± 1°C, 80 ± 10% RH and the viability of the fungal conidia was recorded at different time points. Tube bioassays were used to infect insecticide-resistant (VKPER) and insecticide-susceptible (SKK) strains of <it>An. gambiae s.s</it>., and survival analysis was used to determine effects of mosquito strain, fungus species or time since fungal treatment of the net.</p> <p>Results</p> <p>The resistant VKPER strain was significantly more susceptible to fungal infection than the insecticide-susceptible SKK strain. Furthermore, <it>B. bassiana </it>was significantly more virulent than <it>M. anisopliae </it>for both mosquito strains, although this may be linked to the different viabilities of these fungal species. The viability of both fungal species decreased significantly one day after application onto polyester netting when compared to the viability of conidia remaining in suspension.</p> <p>Conclusions</p> <p>The insecticide-resistant mosquito strain was susceptible to both species of fungus indicating that entomopathogenic fungi can be used in resistance management and integrated vector management programmes to target insecticide-resistant mosquitoes. Although fungal viability significantly decreased when applied to the netting, the effectiveness of the fungal treatment at killing mosquitoes did not significantly deteriorate. Field trials over a longer trial period need to be carried out to verify whether polyester netting is a good candidate for operational use, and to see if wild insecticide-resistant mosquitoes are as susceptible to fungal infection as the VKPER strain.</p

Rapid cultural adaptation can facilitate the evolution of large-scale cooperation

Over the past several decades, we have argued that cultural evolution can facilitate the evolution of large-scale cooperation because it often leads to more rapid adaptation than genetic evolution, and, when multiple stable equilibria exist, rapid adaptation leads to variation among groups. Recently, Lehmann, Feldman, and colleagues have published several papers questioning this argument. They analyze models showing that cultural evolution can actually reduce the range of conditions under which cooperation can evolve and interpret these models as indicating that we were wrong to conclude that culture facilitated the evolution of human cooperation. In the main, their models assume that rates of cultural adaption are not strong enough compared to migration to maintain persistent variation among groups when payoffs create multiple stable equilibria. We show that Lehmann et al. reach different conclusions because they have made different assumptions. We argue that the assumptions that underlie our models are more consistent with the empirical data on large-scale cultural variation in humans than those of Lehmann et al., and thus, our models provide a more plausible account of the cultural evolution of human cooperation in large groups

Divided attention selectively impairs memory for self-relevant information

Information that is relevant to oneself tends to be remembered more than information that relates to other people, but the role of attention in eliciting this "self-reference effect" is unclear. In the present study, we assessed the importance of attention in self-referential encoding using an ownership paradigm, which required participants to encode items under conditions of imagined ownership by themselves or by another person. Previous work has established that this paradigm elicits a robust self-reference effect, with more "self-owned" items being remembered than "other-owned" items. Access to attentional resources was manipulated using divided-attention tasks at encoding. A significant self-reference effect emerged under full-attention conditions and was related to an increase in episodic recollection for self-owned items, but dividing attention eliminated this memory advantage. These findings are discussed in relation to the nature of self-referential cognition and the importance of attentional resources at encoding in the manifestation of the self-reference effect in memory

Electroosmosis modulated peristaltic biorheological flow through an asymmetric microchannel : mathematical model

A theoretical study is presented of peristaltic hydrodynamics of an aqueous electrolytic nonNewtonian Jeffrey bio-rheological fluid through an asymmetric microchannel under an applied axial electric field. An analytical approach is adopted to obtain the closed form solution for velocity, volumetric flow, pressure difference and stream function. The analysis is also restricted under the low Reynolds number assumption and lubrication theory approximations. Debye-Hückel linearization (i.e. wall zeta potential ≤ 25mV) is also considered. Streamline plots are also presented for the different electro-osmotic parameter, varying magnitudes of the electric field (both aiding and opposing cases) and for different values of the ratio of relaxation to retardation time parameter. Comparisons are also included between the Newtonian and general non-Newtonian Jeffrey fluid cases. The results presented here may be of fundamental interest towards designing lab-on-a-chip devices for flow mixing, cell manipulation, micro-scale pumps etc. Trapping is shown to be more sensitive to an electric field (aiding, opposing and neutral) rather than the electro-osmotic parameter and viscoelastic relaxation to retardation ratio parameter. The results may also help towards the design of organ-on-a-chip like devices for better drug design