We show that drought-induced changes in the intensity of riots lead to moves towards democracy in sub-Saharan Africa, and that these changes are often a result of concessions made as a result of the riots. This provides evidence that low-intensity conflict can have a substantial short-run impact on democratic change, and supports the “window of opportunity” hypothesis: droughts lead to an incre...

Nuclear import of some viral proteins depends on importin a proteins. However, no preferences of distinct a-importins for any viral protein import have been demonstrated. We used in vitro import assays and observed that all ubiquitously expressed human importin a isoforms mediate nuclear translocation of adenoviral E1A. Competition with nucleoplasmin suggests that importin a3 is the most effici...

This paper addresses the problem of guaranteed delivery of messages with hard deadlines in a DQDB network. We present a cyclic reservation scheme capable of allocating bandwidth with any arbitrary granular-ity and provide deterministic delay guarantees. We propose two implementations of the allocation scheme within the framework of DQDB medium access control protocol. The proposed implementatio...

The nuclear import of proteins typically requires the presence of a nuclear localization sequence (NLS). Some proteins have more than one NLS, but the significance of having multiple NLSs is unclear. The enzyme 5-lipoxygenase (5-LO) has three NLSs that, unlike the tight cluster of basic residues of the classical SV40 large T antigen NLS, contain dispersed basic residues. When attached to green ...

It is well established that import of proteins into mitochondria can occur after their complete synthesis by cytosolic ribosomes. Recently, an additional model was revived, proposing that some proteins are imported co-translationally. This model entails association of ribosomes with the mitochondrial outer membrane, shown to be mediated through the ribosome-associated chaperone nascent chain-as...

Mitochondria import nuclear-encoded precursor proteins to four different subcompartments. Specific import machineries have been identified that direct the precursor proteins to the mitochondrial outer membrane, inner membrane or matrix, respectively. However, a machinery dedicated to the import of mitochondrial intermembrane space (IMS) proteins has not been found so far. We have identified the...

GTP-hydrolysis, the small ras-related GTP-binding protein Ran and its cognate guanosine nucleotide exchange factor, the RCC1 gene product, have recently been identified as essential components of the protein nuclear import pathway. In this report we use three independent approaches to investigate the role of these components in U1 snRNP nuclear import in somatic cells. (i) Using a somatic cell ...

Most chloroplast and mitochondrial proteins are synthesized with N-terminal presequences that direct their import into the appropriate organelle. In this report we have analyzed the specificity of standard in vitro assays for import into isolated pea chloroplasts and mitochondria. We find that chloroplast protein import is highly specific because mitochondrial proteins are not imported to any d...