BABY BOOM target genes provide diverse entry points into cell proliferation and cell growth pathways

Ectopic expression of the Brassica napus BABY BOOM (BBM) AP2/ERF transcription factor is sufficient to induce spontaneous cell proliferation leading primarily to somatic embryogenesis, but also to organogenesis and callus formation. We used DNA microarray analysis in combination with a post-translationally regulated BBM:GR protein and cycloheximide to identify target genes that are directly activated by BBM expression in Arabidopsis seedlings. We show that BBM activated the expression of a largely uncharacterized set of genes encoding proteins with potential roles in transcription, cellular signaling, cell wall biosynthesis and targeted protein turnover. A number of the target genes have been shown to be expressed in meristems or to be involved in cell wall modifications associated with dividing/growing cells. One of the BBM target genes encodes an ADF/cofilin protein, ACTIN DEPOLYMERIZING FACTOR9 (ADF9). The consequences of BBM:GR activation on the actin cytoskeleton were followed using the GFP:FIMBRIN ACTIN BINDING DOMAIN2 (GFP:FABD) actin marker. Dexamethasone-mediated BBM:GR activation induced dramatic changes in actin organization resulting in the formation of dense actin networks with high turnover rates, a phenotype that is consistent with cells that are rapidly undergoing cytoplasmic reorganization. Together the data suggest that the BBM transcription factor activates a complex network of developmental pathways associated with cell proliferation and growth

Media generations and their advertising attitudes and avoidance

This cross-national survey (N = 5784) examined generational differences in media use, advertising attitudes and avoidance for five media (websites, social media, mobile phones, television, newspapers) in six countries (Germany, Spain, United Kingdom, United States, France, and the Netherlands). The results showed that the net generation and the newspaper generation, but not the TV generation, were clearly distinct in the frequency of their media use in all six countries. For advertising attitudes, generational patterns were visible, however, neither for all media nor in all countries. When generational differences did occur, the net generation was on the positive end, whereas the newspaper generation was usually the most negative. For advertising avoidance, generational patterns were less present and consistent. The findings point out interesting directions for future research. Practical implications for advertisers and media planners are discussed

Patients inverted question mark expectations of variation in quality of care relates to their search for comparative performance information

Contains fulltext : 138965.pdf (publisher's version ) (Open Access)BackgroundChoice of hospital based on comparative performance information (CPI) was introduced for Dutch healthcare consumers at least 5 years ago, but CPI use has not yet become commonplace. Our aim was to assess the role of patients inverted question mark expectations regarding variation in the quality of hospital care in determining whether they search for CPI.MethodsA questionnaire (for a cross-sectional survey) was distributed to 475 orthopaedic patients in a consecutive sample, who underwent primary hip or knee replacement in a university, teaching, or community hospital between September 2009 and July 2010.ResultsOf the 302 patients (63%) who responded, 13% reported searching for CPI to help them choose a hospital. People who expected quality differences between hospitals (67%) were more likely to search for CPI (OR =3.18 [95% CI: 1.02 inverted question mark9.89]; p <0.04) than those who did not. Quality differences were most often expected in hospital reputation, distance, and accessibility. Patients who did not search for CPI stated that they felt no need for this type of information.ConclusionPatients inverted question mark expectations regarding variation in quality of care are positively related to their reported search for CPI. To increase the relevance of CPI for patients, future studies should explore the underlying reasoning of patients about meaningful quality-of-care variation between hospitals

Intracellulair Organization: A Prerequisite for Root Hair Elongation and Cell Wall Deposition

Cell growth requires not only production of matter, but in addition, the targeting, transport, and delivery of this matter to the site of cell expansion. Thus, a proper organization of cell structure, the cytoarchitecture, is a necessity for cell elongation. The actual process of cell growth in a cell under turgor pressure is Golgi vesicle membrane insertion into the existing cell wall at the site of wall expansion. If one of these prerequisites is missing, growth will not occur. Thus, the Golgi vesicle is the unit of cell growth. The tip-growing cell with robust cell expansion at a defined site is a model system " par excellence" to study this process. In this chapter, we discuss the so-called tip-growth unit, i.e., the assemblage of nucleus, endoplasmic reticulum, polysomes, Golgi bodies, Golgi vesicles, exocytosis machinery, clathringcoated vesicles, endosomes, and mitochondria that specifically accumulate in the (sub)apical region of tip-growing root hairs, all working in concert to enable apical growth. The last paragraph of this chapter reviews methods used for the visualization of cellulose microfibril

Control of the actin cytoskeleton in plant cell growth

Plant cells grow through increases in volume and cell wall surface area. The mature morphology of a plant cell is a product of the differential rates of expansion between neighboring zones of the cell wall during this process. Filamentous actin arrays are associated with plant cell growth, and the activity of actin-binding proteins is proving to be essential for proper cell morphogenesis. Actin-nucleating proteins participate in cell expansion and cell plate formation whereas the recycling of actin monomers is required to maintain actin dynamics and controlled growth. Coordination of actin-binding protein activity and other aspects of cytoskeletal behavior during cell development maintains cohesive cell expansion. Emerging plant signaling networks are proving to be powerful regulators of morphology-shaping cytoskeletal activity, and in this review we highlight current research in actin network regulatio

Root hairs

Root hairs, the tip-growing extensions of root epidermal cells, are a model system for answering many plant cell and developmental biology research questions. This book, written by experts in the field, covers the research up to 2008 on cellular, genetic, electrophysiological and developmental aspects of root hair growth, as well as the interaction of root hairs with rhizobia and mycorrhizae in the establishment of symbiosis. With a wealth of information on technical and experimental aspects useful in the laboratory, this comprehensive book is a valuable resource for researchers and students in the broad field of plant cell and molecular biolog

The cytoskeleton in plant cell growth: lessons from root hairs

In this review, we compare expansion of intercalary growing cells, in which growth takes place over a large surface, and root hairs, where expansion occurs at the tip only. Research that pinpoints the role of the cytoskeleton and the cytoplasmic free calcium in both root hairs and intercalary growing cells is reviewed. From the results of that research, we suggest experiments to be carried out on intercalary growing cells to test our hypotheses on plant cell expansion. Our main hypothesis is that instability of the cortical actin cytoskeleton determines the location where expansion takes place and the amount of expansion

Sphere size distributions from finite thickness sections: a forward approach employing a genetic algorithm

We formulate, implement and test a robust method of determining sphere size distributions from finite thickness planar sections. The method uses a forward approach in which populations of proposed distributions are tested against the input data and refined using a genetic algorithm. This method is then applied to a real-world data set concerning endo- and exocytotic vesicles in the apical region of tip growing pollen tubes of Arabidopsis thaliana

Sphere size distributions from finite thickness sections: a forward approach employing a genetic algorithm

We formulate, implement and test a robust method of determining sphere size distributions from finite thickness planar sections. The method uses a forward approach in which populations of proposed distributions are tested against the input data and refined using a genetic algorithm. This method is then applied to a real-world data set concerning endo- and exocytotic vesicles in the apical region of tip growing pollen tubes of Arabidopsis thaliana