Mission Operations Planning and Scheduling System (MOPSS)

MOPSS is a generic framework that can be configured on the fly to support a wide range of planning and scheduling applications. It is currently used to support seven missions at Goddard Space Flight Center (GSFC) in roles that include science planning, mission planning, and real-time control. Prior to MOPSS, each spacecraft project built its own planning and scheduling capability to plan satellite activities and communications and to create the commands to be uplinked to the spacecraft. This approach required creating a data repository for storing planning and scheduling information, building user interfaces to display data, generating needed scheduling algorithms, and implementing customized external interfaces. Complex scheduling problems that involved reacting to multiple variable situations were analyzed manually. Operators then used the results to add commands to the schedule. Each architecture was unique to specific satellite requirements. MOPSS is an expert system that automates mission operations and frees the flight operations team to concentrate on critical activities. It is easily reconfigured by the flight operations team as the mission evolves. The heart of the system is a custom object-oriented data layer mapped onto an Oracle relational database. The combination of these two technologies allows a user or system engineer to capture any type of scheduling or planning data in the system's generic data storage via a GUI

Two Accounts for Why Adolescent Savings Is Predictive of Young Adult Savings: An Economic Socialization Perspective and an Institutional Perspective

Economic socialization and the institutional theory of saving offer different accounts for why adolescents\u27 savings predicts savings in young adulthood. Economic socialization theory emphasizes the role that the family plays in whether or not youth develop a future time orientation and a habit of saving. Conversely, an institutional theory is built on the premise that acquisition of financial knowledge and resources are strongly influenced by structural failures related to social class and race. Using longitudinal data (N = 694) from the Panel Study of Income Dynamics (PSID) and its supplements, this paper asks whether having savings as an adolescent (ages 13 to 17) predicts having savings as a young adult (ages 18 to 22). Policy implications are discussed using both approaches and conclusions are drawn about how the approaches can be combined to create a saving intervention for adolescents

Adaptive evolution of centromere proteins in plants and animals

BACKGROUND: Centromeres represent the last frontiers of plant and animal genomics. Although they perform a conserved function in chromosome segregation, centromeres are typically composed of repetitive satellite sequences that are rapidly evolving. The nucleosomes of centromeres are characterized by a special H3-like histone (CenH3), which evolves rapidly and adaptively in Drosophila and Arabidopsis. Most plant, animal and fungal centromeres also bind a large protein, centromere protein C (CENP-C), that is characterized by a single 24 amino-acid motif (CENPC motif). RESULTS: Whereas we find no evidence that mammalian CenH3 (CENP-A) has been evolving adaptively, mammalian CENP-C proteins contain adaptively evolving regions that overlap with regions of DNA-binding activity. In plants we find that CENP-C proteins have complex duplicated regions, with conserved amino and carboxyl termini that are dissimilar in sequence to their counterparts in animals and fungi. Comparisons of Cenpc genes from Arabidopsis species and from grasses revealed multiple regions that are under positive selection, including duplicated exons in some grasses. In contrast to plants and animals, yeast CENP-C (Mif2p) is under negative selection. CONCLUSIONS: CENP-Cs in all plant and animal lineages examined have regions that are rapidly and adaptively evolving. To explain these remarkable evolutionary features for a single-copy gene that is needed at every mitosis, we propose that CENP-Cs, like some CenH3s, suppress meiotic drive of centromeres during female meiosis. This process can account for the rapid evolution and the complexity of centromeric DNA in plants and animals as compared to fungi

DigitalCommons Users Discuss the bepress Acquisition

Since the acquisition of the Berkeley Electronic Press (bepress) by Elsevier last summer, there has been much discussion online, in listserves, and elsewhere about what that development means for the future of open access and scholarly communications. The people most directly affected are the users of the bepress DigitalCommons repository hosting service. Some have recoiled in horror at the new ownership situation, others are waiting to see what happens next. This is a panel discussion by current users concerning what they see in the road ahead, including what they regard as essential services, possible options, functionality requirements, and necessary safeguards