Hydraulic conductivity of the xylem is computed as the quotient of mass fiow rate and pressure gradient. Measurements on excised plant stems can be difficult to interpret because of timedependent reductions in fiow rate, and because of variable degrees of embolism. Using Acer saccharum Marsh, stems, we found that certain perfusing solutions including dilute fixatives (e.g. 0.05% formaldehyde) a...

“Reserve” hypotheses in neurodegenerative disease are theoretical concepts that attempt to explain how some individuals are able to maintain normal cognition despite pathologic disease burden sufficient to cause cognitive decline or overt dementia in others. This idea was born out of the seminal work of Katzman et al. who described, at postmortem, a subset of older individuals with preserved co...

in medieval islamic persia, mina was known as a general term for enameling on metal, glass and ceramic. consequently, in modern times mina’i is one of the most important types of islamic ceramic production and identified by stone paste body and multicolored polychrome over-glazes which represent figural, geometric and floral designs as well as calligraphic perform. additionally, mina’i wares ar...

Taking a memory test not only assesses what one knows, but also enhances later retention, a phenomenon known as the testing effect. We studied this effect with educationally relevant materials and investigated whether testing facilitates learning only because tests offer an opportunity to restudy material. In two experiments, students studied prose passages and took one or three immediate free-...

Fluorescence Correlation Spectroscopy (FCS) yields measurement parameters (number of molecules, diffusion time) that characterize the concentration and kinetics of fluorescent molecules within a supposedly known observation volume. Absolute derivation of concentrations and diffusion constants therefore requires preliminary calibrations of the confocal Point Spread Function with phantom solution...

generative disorder with insidious onset and progressive course, which prevalence increases with the age. It is characterized by neuronal degeneration and death, related to the deposition in the brain of the amyloid β 1–42 peptide and the hyperphosphorylated tau protein, and initially affects brain areas, namely the hippocampus and other medial temporal lobe structures, which are important for ...

Retrieval enhances long-term retention. However, reactivation of a memory also renders it susceptible to modifications as shown by studies on memory reconsolidation. The present study explored whether retrieval diminishes or enhances subsequent retroactive interference (RI) and intrusions. Participants learned a list of objects. Two days later, they were either asked to recall the objects, give...