The initiation of radicle growth during seed germination may be driven by solute accumulation and increased turgor pressure, by cell wall relaxation, or by weakening of tissues surrounding the embryo. To investigate these possibilities, imbibition kinetics, water contents, and water (Psi) and solute (psi(s)) potentials of intact muskmelon (Cucumis melo L.) seeds, decoated seeds (testa removed, ...

Epigenetically inherited aggregates of the yeast prion [PSI+] cause genomewide readthrough translation that sometimes increases evolvability in certain harsh environments. The effects of natural selection on modifiers of [PSI+] appearance have been the subject of much debate. It seems likely that [PSI+] would be at least mildly deleterious in most environments, but this may be counteracted by i...

Assembly of retrovirus particles normally entails the selective encapsidation of viral genomic RNA. However, in the absence of packageable viral RNA, assembly is still efficient, and the released virus-like particles (termed "Psi-" particles) still contain roughly normal amounts of RNA. We have proposed that cellular mRNAs replace the genome in Psi- particles. We have now analyzed the mRNA cont...

BACKGROUND Due to the lacking specificity of symptoms making a correct diagnosis can be a challenge in children with medulloblastoma. This can lead to prediagnostic symptomatic intervals (PSIs) of several weeks to months. It is unknown whether the length of the PSI is associated with an inferior survival outcome in this population. METHODS To study the association of PSI with disease stage at...

Electrical potentials in cell walls (psi(Wall)) and at plasma membrane surfaces (psi(PM)) are determinants of ion activities in these phases. The psi(PM) plays a demonstrated role in ion uptake and intoxication, but a comprehensive electrostatic theory of plant-ion interactions will require further understanding of psi(Wall). psi(Wall) from potato (Solanum tuberosum) tubers and wheat (Triticum ...

OBJECTIVES To investigate whether there are two stable types of paranoia, 'poor me' and 'bad me', as described by Trower and Chadwick (1995), and whether beliefs about the deservedness of persecution are associated with psychological measures. METHODS In-patients experiencing persecutory delusions were assigned either to 'poor me' (PM) or 'bad me'(BM) groups, according to their rating of a pe...

The molecular chaperone network plays a critical role in the formation and propagation of self-replicating yeast prions. Not only do individual prions differ in their requirements for certain chaperones, but structural variants of the same prion can also display distinct dependences on the chaperone machinery, specifically Hsp104. The AAA+ ATPase Hsp104 is a disaggregase required for the mainte...

Pre-illumination of cucumber leaf discs at 4 degrees C with low-irradiance white light (i) led to a marked decrease in the extent of photo-oxidation of P700 (the special chlorophyll pair in the PSI reaction center) in actinic light at room temperature and (ii) hastened the post-illumination re-reduction of P700+. Quantifying the linear, cyclic and stroma-sourced electron fluxes to P700+ in two ...

Memory consolidation and reconsolidation require kinase activation and protein synthesis. Blocking either process during or shortly after training or recall disrupts memory stabilization, which suggests the existence of a critical time window during which these processes are necessary. Using a computational model of kinase synthesis and activation, we investigated the ways in which the dynamics...

The solution manifold of the system of nonlinear differential equations representing a BWR needs to be examined to understand its dynamical behavior. In particular, stable or unstable fixed points and stable or unstable oscillatory solutions (or turning points/saddle node bifurcations) are of paramount interest. In this framework integrated BWR (system) codes and simplified BWR models (reduced ...