BACKGROUND The flora of Saudi Arabia is one of the richest biodiversity areas in the Arabian Peninsula and comprises very important genetic resources of crop and medicinal plants. The present study was designed to investigate the cytotoxicity and the antibacterial activities of the organic extracts from twenty six Saudi Arabian medicinal plants. The study was also extended to the investigation ...

Effects of food quality and quantity on consumers are neither independent nor interchangeable. Although consumer growth and reproduction show strong variation in relation to both food quality and quantity, the effects of food quality or food quantity have usually been studied in isolation. In two experiments, we studied the growth and reproduction in three filter-feeding freshwater zooplankton ...

Oxidative stress is involved in the pathogenesis of neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. Astrocytes, the most abundant glial cells in the brain, protect neurons from reactive oxygen species (ROS) and provide them with trophic support, such as glial-derived neurotrophic factor (GDNF). Thus, any damage to astrocytes will affect neuronal survival. In the present...

1. We combined ecological surveys, life table studies, microscopy and molecular sequencing to determine the development, ecology, pathology and phylogeny of Polycaryum laeve, an endoparasite of cladocerans. We report the first records of P. laeve from North America, where we have used a polymerase chain reaction primer and microscopic examination to confirm infections in 14 lakes. Infections ar...

The bee genus Pseudoanthidium is represented by nine species in Europe. Of these species, nanum the most widespread, occurs mainly xerothermic open habitats and creates nests various cavity types. In this study, we provide information on nest structure of reed stalks oak galls about its parasitic species. We first report P. as a host Xylophrurus augustus (Ichneumonidae). biology much rarer rela...