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Because traditional electric power distribution systems have been designed assuming the primary substation is the sole source of power and short-circuit capacity, DR interconnection results in operating situations that do not occur in a conventional system. This paper discusses several system issues which may be encountered as DR penetrates into distribution systems. The voltage issues covered are the DR impact on system voltage, interaction of DR and capacitor operations, and interaction of DR and voltage regulator and LTC operations. Protection issues include fuse coordination, feeding faults after utility protection opens, impact of DR on interrupting rating of devices, faults on adjacent feeders, fault detection, ground source impacts, single phase interruption on three phase line, recloser coordination and conductor burndown. Loss of power grid is also discussed, including vulnerability and overvoltages due to islanding and coordination with reclosing. Also covered separately are system restoration and network issues. Index Terms--DER, distributed generation (DG), distribution resources (DR), DG integration.

We describe a developmental, genetic, and molecular analysis of the sole Drosophila member of the BAG family of genes, which is implicated in stress response and survival in mammalian cells. We show that the gene, termed starvin (stv), is expressed in a highly tissue-specific manner, accumulating primarily in tendon cells following germ-band retraction and later in somatic muscles and the esophagus during embryonic stage 15. We show that stv expression falls within known tendon and muscle cell transcriptional regulatory cascades, being downstream of stripe, but not of another tendon transcriptional regulator, delilah, and downstream of the muscle regulator, mef-2. We generated a series of stv alleles and, surprisingly, given the muscle and tendon-specific embryonic expression of stv, found that the gross morphology and function of somatic muscles is normal in stv mutants. Nonetheless, sty mutant larvae exhibit a striking and fully penetrant mutant phenotype of failure to grow after hatching and a severely impaired ability to take up food. Our study provides the first report of an essential, developmentally regulated BAG-family gene.

Cyclin E together with its kinase partner Cdk2 is a critical regulator of entry into S phase. To identify novel genes that regulate the G1- to S-phase transition within a whole animal we made use of a hypomorphic cyclin E mutation, Dmcyc[E.sup.JP], which results in a rough eye phenotype. We screened the X and third chromosome deficiencies, tested candidate genes, and carried out a genetic screen of 55,000 EMS or X-ray-mutagenized flies for second or third chromosome mutations that dominantly modified the Dmcyc[E.sup.JP] rough eye phenotype. We have focused on the Dmcyc[E.sup.JP] suppressors, S(Dmcyc[E.sup.JP]), to identify novel negative regulators of S-phase entry. There are 18 suppressor gene groups with more than one allele and several genes that are represented by only a single allele. All S(Dmcyc[E.sup.JP]) tested suppress the Dmcyc[E.sup.JP] rough eye phenotype by increasing the number of S phases in the postmorphogenetic furrow S-phase band. By testing candidates we have identified several modifier genes from the mutagenic screen as well as from the deficiency screen. Dmcyc[E.sup.JP] suppressor genes fall into the classes of: (1) chromatin remodeling or transcription factors; (2) signaling pathways; and (3) cytoskeletal, (4) cell adhesion, and (5) cytoarchitectural tumor suppressors. The cytoarchitectural tumor suppressors include scribble, lethal-2-giant-larvae (lgl), and discs-large (dlg), loss of function of which leads to neoplastic tumors and disruption of apical-basal cell polarity. We further explored the genetic interactions of scribble with S(Dmcyc[E.sup.JP]) genes and show that bypomorphic scribble mutants exhibit genetic interactions with lgl, scab ([alpha]PS3-integrin--cell adhesion), phyllopod (signaling), dEB1 (microtubule-binding protein--cytoskeletal)' and moira (chromatin remodeling). These interactions of the cytoarchitectural suppressor gene, scribble, with cell adhesion, signaling, cytoskeletal, and chromatin remodeling genes, suggest that these genes may act in a common pathway to negatively regulate cyclin E or S-phase entry.

The Drosophila cyclin E (DmcycE) gene gives rise to two transcripts encoding proteins that differ at their N termini, DmcycEII and DmcycEI. This study presents the first in vivo dissection of Cyclin E function. Ectopic expression studies using N- and C-terminal deletions of DmcycEI revealed that a region of 322 residues surrounding the cyclin box is sufficient to induce entry of [G.sub.1]-arrested larval eye imaginal disc cells into S phase. Ectopic expression of DmcycEI in the eye disc has been previously shown to drive anterior, but not posterior, [G.sub.1]-phase cells within the morphogenetic furrow (MF) into S phase. Significantly, ectopic expression of DmcycEII and N-terminal deletions of DmcycEI were able to drive all [G.sub.1] cells within the morphogenetic furrow into S phase, while a C-terminal deletion of DmcycEI could not. The p21 homolog Dacapo was shown by yeast two-hybrid, coimmunolocalization, and in vivo functional studies not to be the mediator of the DmcycEI inhibition in posterior part of the MF. Taken together, these results reveal a novel zone within the posterior region of the MF where DmcycEI but not DmcycEII function is inhibited, and suggest that DmcycEII is a more potent inducer of S phase. Key Words: Cyclin E; Dacapo; [G.sub.1]-S phase; cell cycle; Drosophila; development.

Members of the recently discovered ARID (AT-rich interaction domain) family of DNA-binding proteins are found in fungi and invertebrate and vertebrate metazoans. ARID-encoding genes are involved in a variety of biological processes including embryonic development, cell lineage gene regulation and cell cycle control. Although the specific roles of this domain and of ARID-containing proteins in transcriptional regulation are yet to be elucidated, they include both positive and negative transcriptional regulation and a likely involvement in the modification of chromatin structure.

A putative exchange factor for Rho1 GTPase is discussed. The factor is necessary for Drosophila cytokinesis initiation. Cytokinesis ensures success of the cell cycle and distribution of chromosomes, organelles and cytoplasm in daughter cells. Formation and constriction of an actomyosin contractile ring drives progression of a cleavage furrow to bring about cytokinesis. Results of a recent study show Drosophila Pebble (Pbl), the putative exchange factor, to be a RhoGEF specifically needed for cytokinesis and linked through Rho1 activity to reorganization of the actin cytoskeleton at the cleavage furrow.

It has been possible to identify regions that play a significant part in the specificity of function of H2AZ, a variant of the histone protein H2A which is needed for the survival of Drosophila melanogaster. It was established that the unique feature of Drosophila H2AZ lies in its carboxy-terminal domain, rather than its histone fold. The C-terminal region maps to a short alpha-helix in H2A situated deep inside the nucleosome core.

We have generated and characterized a Drosophila cyclin E hypomorphic mutation, [DmccycE.sup.JP], that is homozygous viable and fertile, but results in adults with rough eyes. The mutation arose from an internal deletion of an existing P[[w.sup.+]lacZ] element inserted 14 kb upstream of the transcription start site of the DmcycE zygotic mRNA. The presence of this deleted P element, but not the P[[w.sup.+]lacZ] element from which it was derived, leads to a decreased level of DmcycE expression during eye imaginal disc development. Eye imaginal discs from [DmcycE.sup.JP] larvae contain fewer S phase cells, both anterior and posterior to the morphogenetic furrow. This results in adults with small rough eyes, largely due to insufficient numbers of pigment cells. Altering the dosage of the Drosophila cdk2 homolog, cdc2c, retinoblastoma, or [p21.sup.CIP1] homolog dacapo, which encode proteins known to physically interact with Cyclin E, modified the [DmcycE.sup.JP] rough eye phenotype as expected. Decreasing the dosage of the S phase transcription factor gene, dE2F, enhanced the [DmcycE.sup.JP] rough eye phenotype. Surprisingly, mutations in G2/M phase regulators cyclin A and string (cdc25), but not cyclin B1, B3, or cdc2, enhanced the [DmcycE.sup.JP] phenotype without affecting the number of cells entering S phase, but by decreasing the number of cells entering mitosis. Our analysis establishes the [DmcycE.sup.JP] allele as an excellent resource for searching for novel cyclin E genetic interactors. In addition, this analysis has identified cyclin A and string as [DmcycE.sup.JP] interactors, suggesting a novel role for cyclin E in the regulation of Cyclin A and String function during eye development.

The highly conserved regulatory mechanisms that control progression of a cell through the cell cycle do not, alone, explain the programmed control of cell proliferation during animal development. Additional controls must coordinate the cell cycle regulators with developmental regulatory events. Here we report studies of cell cycle control in the imaginal tissues of Drosophila melanogaster, specifically in situations where cell cycle progression is regulated by varying the length of the G2 phase. We show that G2-phase arrest in late larval wing imaginal disks requires transcriptional control of stg, a mitotic inducer that encodes a D. melanogaster homologue of the Scizosaccharomyces pombe [p80.sup.cdc25] phosphatase. In a second study, string transcriptional regulation was also shown to be important for G2-phase regulation in eye disk cells posterior to the morphogenetic furrow. Finally, unlike all other situations described to date, string transcriptional regulation was found not to be the cause of [G.sub.2] arrest in abdominal histoblasts, these cells being refractory to ectopic expression of stg. This study further establishes string as an important regulator of [G.sub.2] phase during D. melanogaster development, but also reveals that at least one additional mechanism is utilized to control [G.sub.2]-phase length and thus cell proliferation in different developmental contexts.

Studies of Drosophila embryogenesis suggest that Drosophila cyclin E (DmcycE) regulates progression through S phase through the formation of a complex with Dmcdc2c kinase. The downregulation of DmcycE results in suppressed embryonic proliferation. DmcycE mutant embryos do not exhibit endoreplication reinforcing the concept of DmcycE's crucial role in cell proliferation.

Abstract Background Anthozoan cnidarians are amongst the simplest animals at the tissue level of organization, but are surprisingly complex and vertebrate-like in terms of gene repertoire. As major components of tropical reef ecosystems, the stony corals are anthozoans of particular ecological significance. To better understand the molecular bases of both cnidarian development in general and coral-specific processes such as skeletogenesis and symbiont acquisition, microarray analysis was carried out through the period of early development – when skeletogenesis is initiated, and symbionts are first acquired. Results Of 5081 unique peptide coding genes, 1084 were differentially expressed (P ≤ 0.05) in comparisons between four different stages of coral development, spanning key developmental transitions. Genes of likely relevance to the processes of settlement, metamorphosis, calcification and interaction with symbionts were characterised further and their spatial expression patterns investigated using whole-mount in situ hybridization. Conclusion This study is the first large-scale investigation of developmental gene expression for any cnidarian, and has provided candidate genes for key roles in many aspects of coral biology, including calcification, metamorphosis and symbiont uptake. One surprising finding is that some of these genes have clear counterparts in higher animals but are not present in the closely-related sea anemone Nematostella. Secondly, coral-specific processes (i.e. traits which distinguish corals from their close relatives) may be analogous to similar processes in distantly related organisms. This first large-scale application of microarray analysis demonstrates the potential of this approach for investigating many aspects of coral biology, including the effects of stress and disease.

Understanding the work of international organizations requires an understanding of the relationship between language and culture, a relationship evident in the activities of the international organizations. This relationship is partly responsible for the negative image of such organizations. Research in the sociology of international organizations is needed. (Author/MSE)