The CLAVATA and SHOOT MERISTEMLESS loci competitively regulate meristem activity in Arabidopsis

The CLAVATA (CLV1 and CLV3) and SHOOT MERISTEMLESS (STM) genes specifically regulate shoot meristem development in Arabidopsis. CLV and STH appear to have opposite functions: c1v1 and Clv3 mutants accumulate excess undifferentiated cells in the shoot and floral meristem, while stm mutants fail to form the undifferentiated cells of the shoot meristem during embryonic development. We have identified a weak allele of stm (stm-2) that reveals STM is not only required for the establish- ment of the shoot meristem, but is also required for the continued maintenance of undifferentiated cells in the shoot meristem and for proper proliferation of cells in the floral meristem. We have found evidence of genetic interactions between the CLV and STM loci. clv1 and c1v3 mutations partially suppressed the stm-1 and stm-2 phenotypes, and were capable of suppression in a dominant fashion. clv stm double mutants and plants homozygous for stm but heterozygous for clv, while still lacking an embryonic shoot meristem, exhibited greatly enhanced postembryonic shoot and floral meristem development. Although stm phenotypes are recessive, stm mutations dominantly suppressed clv homozygous and heterozygous phenotypes. These results indicate that the stm phenotype is sensitive to the levels of CLV activity, while the clv phenotype is sensitive to the level of STM activity. We propose that these genes play related but opposing roles in the regulation of cell division and/or cell differentiation in shoot and floral meristems

CLAVATA3 is a specific regulator of shoot and floral meristem development affecting the same processes as CLAVATA1

We have previously described the phenotype of Arabidopsis thaliana plants with mutations at the CLAVATA1 (CLV1) locus (Clark, S. E., Running, M. P. and Meyerowitz, E. M. (1993) Development 119, 397-418). Our investigations demonstrated that clv1 plants develop enlarged vegetative and inflorescence apical meristems, and enlarged and indeterminate floral meristems. Here, we present an analysis of mutations at a separate locus, CLAVATA3(CLV3), that disrupt meristem development in a manner similar to clv1mutations. clv3 plants develop enlarged apical meristems as early as the mature embryo stage. clv3 floral meristems are also enlarged compared with wild type, and maintain a proliferating meristem throughout flower development. clv3 root meristems are unaffected, indicating that CLV3 is a specific regulator of shoot and floral meristem development. We demonstrate that the strong clv3-2 mutant is largely epistatic to clv1 mutants, and that the semi-dominance of clv1 alleles is enhanced by double heterozygosity with clv3 alleles, suggesting that these genes work in the same pathway to control meristem development. We propose that CLV1 and CLV3 are required to promote the differentiation of cells at the shoot and floral meristem

Modernist Urbanism in the Age of Automobility: Producing Space in the Suburbs of Toronto and Prague

Theorizing the effects of the expanding system of automobility has been an important area of inquiry in urban studies. What remains largely absent, though, are concrete investigations into the relationships between automobility and the transformations and production of urban space. Automobility is defined by its contradictions. This dissertation explores how urban planners, architects and theorists have historically responded to and attempted to resolve the contradictions of automobility. I locate these responses within the broader theoretical framework of the production of space, considering how the mode of conceiving space from the 1920s on was directly related to the car and the expanding system of automobility. Automobility as an assemblage of objects, ideologies, and institutions was central to the way architects and planners conceived of urban space: as a work of art. I argue that this conception of space circulated globally, which I show through the work of the Czechoslovak architectural avant-garde theorist Karel Teige in the 1920s and the urban theorist Humphrey Carver in post-war Canada. In this dissertation I explore automobility and the production of space by way of two post-war suburbs: Jižní město (South City) in Prague and Willowdale in Toronto. Both places were considered as solutions to problems associated with automobility and both were key nodes in the circulation of ideas on modernist urbanism. I argue that the building of South City and the rebuilding of Willowdale are the culmination of the circulation of a modernist urbanism across space and over time that attempted to respond to the forces of urbanization and automobility through planning and designing the suburb. Overcoming the contradictions of automobility will involve more than just new technologies of mobility—urban planners, architects and theorists will have to consider the production of a wholly different space for urban life. To move beyond automobility means accounting for the ways the system of automobility unevenly affects city and suburban dwellers. In an attempt to offer a critique of the city-suburb dichotomy, this dissertation argues that to go “beyond automobility” means collapsing the separations that mark both modernism and automobility

Availability, utilization, and perceived benefits of treatment services for secondary victims of sexual assault

The purpose of this study was to examine and identify the current availability, utilization, and perceived benefits of treatment services for secondary victims (i.e. family members/significant others of sexual assault victims)

CLAVATA1, a regulator of meristem and flower development in Arabidopsis

We have investigated the effects on plant development of mutations in the Arabidopsis thaliana CLAVATA1 gene. In clavata1 plants, vegetative, inflorescence and floral meristems are all enlarged relative to wild type. The apical meristem can fasciate in the more severe mutant alleles, and this fasciation can occur prior to the transition to flowering. Flowers of clavata1 plants can have increased numbers of organs in all four whorls, and can also have additional whorls not present in wild-type flowers. Double mutant combinations of clavata1 with agamous, apetala2, apetala3 and pistillata indicate that CLAVATA1 controls the underlying floral meristem structure upon which these homeotic genes act. Double mutant combinations of clavata1 with apetala1 and leafy indicate CLAVATA1 plays a role in establishing and maintaining floral meristem identity, in addition to its role in controlling meristem size. In support of this, RNA expression patterns of AGAMOUS and APETALA1 are altered in clavata1 flowers

Disruption of an RNA helicase/RNAse III gene in Arabidopsis causes unregulated cell division in floral meristems

Arabidopsis thaliana floral meristems are determinate structures that produce a defined number of organs, after which cell division ceases. A new recessive mutant, carpel factory (caf), converts the floral meristems to an indeterminate state. They produce extra whorls of stamens, and an indefinite number of carpels. Thus, CAF appears to suppress cell division in floral meristems. The function of CAF is partially redundant with the function of the CLAVATA (CLV) and SUPERMAN (SUP) genes, as caf clv and caf sup double mutants show dramatically enhanced floral meristem over-proliferation. caf mutant plants also show other defects, including absence of axillary inflorescence meristems, and abnormally shaped leaves and floral organs. The CAF gene was cloned and found to encode a putative protein of 1909 amino acids containing an N-terminal DExH/DEAD-box type RNA helicase domain attached to a C-terminal RNaseIII-like domain. A very similar protein of unknown function is encoded by a fungal and an animal genome. Helicase proteins are involved in a number of processes, including specific mRNA localization and mRNA splicing. RNase III proteins are involved in the processing of rRNA and some mRNA molecules. Thus CAF may act through some type of RNA processing event(s). CAF gives rise to two major transcripts of 2.5 and 6.2 kb. In situ hybridization experiments show that CAF RNA is expressed throughout all shoot tissues

The Future of Cloud-Based Library Systems

The limits of the now-aging integrated library system (ILS) software model are constraining the presence of the library within the new reality of the Internet and interconnected World Wide Web. Whether they are called cloud-based ILS or library services platforms, developing and future systems will move beyond shared library resources on shelves to establishing a shared technological infrastructure for supporting all that libraries do. Cloud-based systems will provide means for management of all library systems, including circulation, cataloging, acquisitions, serials, electronic resources, authentication, the public interface, and analytics for data in the system. All this will allow for greater cooperation among libraries and a strengthening of patron-driven print and digital services, thus getting the information to the user and fulfilling her information needs

Phenotypic plasticity and geographic variation in thermal tolerance and water loss of the tsetse Glossina pallidipes (Diptera: Glossinidae): implications for distribution modelling

Using the tsetse, Glossina pallidipes, we show that physiologic plasticity (resulting from temperature acclimation) accounts for among-population variation in thermal tolerance and water loss rates. Critical thermal minimum (CT(Min)) was highly variable among populations, seasons, and acclimation treatments, and the full range of variation was 9.3 degrees C (maximum value = 3.1 x minimum). Water loss rate showed similar variation (max = 3.7 x min). In contrast, critical thermal maxima (CT(Max)) varied least among populations, seasons, and acclimation treatments, and the full range of variation was only approximately 1 degree C. Most of the variation among the four field populations could be accounted for by phenotypic plasticity, which in the case of CT(Min), develops within 5 days of temperature exposure and is lost rapidly on return to the original conditions. Limited variation in CT(Max) supports bioclimatic models that suggest tsetse are likely to show range contraction with warming from climate change

An Integrated Social Actor and Service Oriented Architecture (SOA) Approach for Improved Electronic Health Record (EHR) Privacy and Confidentiality in the US National Healthcare Information Network (NHIN)

The emerging US National Healthcare Information Network (NHIN) will improve healthcare’s efficacy, efficiency, and safety. The first-generation NHIN being developed has numerous advantages and limitations. One of the most difficult aspects of today’s NHIN is ensuring privacy and confidentiality for personal health data, because family and caregivers have multiple complex legal relationships to a patient. A Social Actor framework is suggested to organize and manage these legal roles, but the Social Actor framework would be very difficult to implement in today’s NHIN. Social Actor Security Management could, however, be effectively implemented using Service Oriented Architectures (SOAs), which are rapidly becoming accepted for supporting complex information exchange across heterogeneous information systems fabrics. The Department of Defense is applying SOA to all of its enterprises. It is using customized simulation and modeling tools to achieve security and robustness goals and to reduce the intrinsic design and implementation risks for SOA’s complex Systems of Systems environment. This paper integrates all of these approaches into a next-generation NHIN-2 design based on a specific Air Force SOA named MCSOA. This NHIN-2 design uses MCSOA to create Security Management, Service Discovery, and Presence Management agents to implement Social Actor support for improved confidentiality and privacy