background and objective: tamoxifen is one of the selective estrogen receptor modulators that exerts estrogen / anti-estrogen effects in various tissues. this study was done to evaluate the effect of chronic administration of tamoxifen on spatial memory and passive avoidance task in adult male wistar rats. methods: in this experimental study, 48 adult male wistar rats were randomly divided into...

Following initial encoding, memories undergo a prolonged period of reorganization. While such reorganization may occur in many different memory systems, its purpose is not clear. Previously, we have shown that recall of recent contextual fear memories engages the dorsal hippocampus (dHPC). In contrast, recall of remote contextual fear memories engages a number of different cortical regions, inc...

Memory based learning algorithms are lazy learners Examples of a task are stored in memory and processing is largely postponed to the time when new instances of the task need to be solved This is then done by extrapolating directly from those remem bered instances which are most similar to the present ones Using memory based learning for Part of Speech tagging has a number of advantages over tr...

objective: this study aimed to investigate the verbal memory and working memory impairment in healthy siblings of patients with schizophrenia.  methods: the purpose of this study was to compare cognitive deficits in siblings of the patients with schizophrenia and control group. a total of 35 unaffected siblings of patients with schizophrenia were selected from the relatives of the patients refe...

Following the advent of molecular assays that measure T cell receptor excision circles (TRECs) present in recent thymic emigrants, it has been conclusively shown that thymopoiesis persists in most adults, but that functional output decreases with age, influencing the maintenance of a diverse and functional T cell receptor (TCR) repertoire. Space flight has been shown to result in a variety of p...

This paper investigates the interaction between cultural evolution and biological evolution in the emergence of phonemic coding in speech. It is observed that our nearest relatives, the primates, use holistic utterances, whereas humans use phonemic utterances. It can therefore be argued that our last common ancestor used holistic utterances and that these must have evolved into phonemic utteran...

We investigate the problem of inferring contiguous ancestral regions (CARs) of the genome of the last common ancestor of all extant amniotes, based on the currently sequenced and assembled amniote genomes as ingroups and three teleost fish genomes as outgroups. We combine a methodological framework using conserved syntenies computed from whole genome alignments of amniote species together with ...

In contrast to adults, the murine neonatal CD4+ compartment contains a high frequency of recent thymic emigrants (RTEs). However, the functional capabilities of these cells in neonates are relatively unknown. Moreover, it has not been determined whether RTEs from neonates and adults are comparable. Here we have directly compared neonatal and adult CD4+ RTEs for the first time, using a transgeni...

The detection of superinfection involves an assessment whether the sequences obtained from a patient diverged from a last common ancestor within that patient, or several lineages were introduced by independent infection events. First we tested whether sequence divergence can be used to identify viral sequences of polyphyletic origin. In principle, a conservative divergence threshold could be es...