bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of 3D Modeling Function Usage on the Design Content of Urban Design Plans in US Cities
Authors: Al-Douri Firas A
Published: December 2009

Some experts suggest that urban design plans in US cities may lack adequate coverage of the essential design aspects of the built environment. Digital models and information technology tools may help designers to visualize and interact with design alternatives and large urban datasets more effectively, thus correcting this problem. Case studies of recent urban design plans that have used digital models may indicate whether these technologies can increase the quality of the plan. This research discusses the role that digital models can play in supporting designers in addressing the essential design aspects. A literature review focused on reviewing secondary sources is used to construct theoretical propositions against which the empirical data can be compared and contrasted. A case study investigates the extents and methods with which modeling functions have been used in developing a selected urban design plan. The findings refute the premise that the plan would inadequately address essential design aspects, and indicate both an effective usage and application of modeling functions in the design process to analyze and represent the urban design aspects. The extent of design aspect coverage is found to be linked to the extensive usage of modeling functions and to the combination of computational and conventional tools, techniques, and modes of presentation. The results are consistent with the research hypothesis that the usage of modeling functions would increase the design content. The effective usage of the modeling functions appears to have improved the quality of the decision-making process by increasing designers' cognitive and communication capabilities and providing a platform for communicating design ideas among and across design teams that lead to wider involvement in the decision making.
Towards a Data-Rich Infrastructure for Housing-Market Research: Deriving Floor-Area Estimates for Individual Properties from Secondary Data Sources
Authors: Orford Scott
Published: December 2009

Recent years have witnessed substantial advances in the precision and availability of digital infrastructure data, remote sensing data, and microscale socioeconomic data for urban areas in many parts of the world. However, these data still remain deficient in detail especially with respect to the fine-grained property-level structural attributes that form the basis of housing-market models and simulations. This lack of detail is hindering the development of house-price models, the validation of housing-market theories, and restricting the quality of empirical input into urban planning. A methodology is developed for deriving estimates of floor area for individual properties from the integration of Ordnance Survey Mastermap data and Environment Agency LiDAR data for an area in the city of Cardiff, Wales. Floor area is an important determinant of house price and a fundamental variable in housing-market models. The estimates are validated against measures of floor area obtained from an estate-agent survey of a large sample of properties. The research investigates the reasons for the differences in the estimates and the implications for the methodology. The paper concludes with a discussion about how the methodology can be developed and some future research applications.
Trace element concentrations in sediments from Kadavu passage, Fiji
Authors: Garimella S. , Lal Rajeev , Deo Ravin , Morrison R. J.
Published: December 2009

Grab sediments, collected from 11 locations from the Pacific Ocean floor in the region between Suva Peninsula and Kadavu Island, Fiji, were investigated for concentrations of 20 elements using neutron activation and high-resolution gamma ray spectroscopy techniques. The sediments were collected at distances between 5-35 km from the mainland and at ocean depths ranging from 500 to 2000 m. A comparison of the elemental abundances of these sediments with those of the Suva lagoon and other nearby locations indicates that the
ocean sediments are likely to be derived from sediments washed out to sea from the mainland. The sediments also show no evidence of any metal contamination from the industrial activity in the Suva metropolitan area.
Some estimation procedures for the inverted exponential distribution
Authors: Prakash Gyan
Published: December 2009

The objective of the present paper is to study the properties of different types of estimators for the parameter of an inverted exponential model. Several distributional properties of the lower record values of the model are also discussed.
A unifying model for timing of walking onset in humans and other mammals
Authors: Garwicz Martin , Christensson Maria , Psouni Elia
Published: December 2009

The onset of walking is a fundamental milestone in motor development of humans and other mammals, yet little is known about what factors determine its timing. Hoofed animals start walking within hours after birth, rodents and small carnivores require days or weeks, and nonhuman primates take months and humans approximately a year to achieve this locomotor skill. Here we show that a key to the explanation for these differences is that time to the onset of walking counts from conception and not from birth, indicating that mechanisms underlying motor development constitute a functional continuum from pre- to postnatal life. In a multiple-regression model encompassing 24 species representative of 11 extant orders of placental mammals that habitually walk on the ground, including humans, adult brain mass accounted for 94% of variance in time to walking onset postconception. A dichotomous variable reflecting species differences in functional limb anatomy accounted for another 3.8% of variance. The model predicted the timing of walking onset in humans with high accuracy, showing that this milestone in human motor development occurs no later than expected given the mass of the adult human brain, which in turn reflects the duration of its ontogenetic development. The timing of motor development appears to be highly conserved in mammalian evolution as the ancestors of some of the species in the sample presented here diverged in phylogenesis as long as 100 million years ago. Fundamental patterns of early human life history may therefore have evolved before the evolution of primates.
A public choice framework for controlling transmissible and evolving diseases
Authors: Althouse Benjamin M. , Bergstrom Theodore C. , Bergstrom Carl T.
Published: December 2009

Control measures used to limit the spread of infectious disease often generate externalities. Vaccination for transmissible diseases can reduce the incidence of disease even among the unvaccinated, whereas antimicrobial chemotherapy can lead to the evolution of antimicrobial resistance and thereby limit its own effectiveness over time. We integrate the economic theory of public choice with mathematical models of infectious disease to provide a quantitative framework for making allocation decisions in the presence of these externalities. To illustrate, we present a series of examples: vaccination for tetanus, vaccination for measles, antibiotic treatment of otitis media, and antiviral treatment of pandemic influenza.
A role for suppressed incisor cuspal morphogenesis in the evolution of mammalian heterodont dentition
Authors: Ohazama Atsushi , Blackburn James , Porntaveetus Thantrira , Ota Masato S. , Choi Hong Y. , Johnson Eric B. , Myers Philip , Oommen Shelly , Eto Kazuhiro , Kessler John A. , Kondo Takashi , Fraser Gareth J. , Streelman J. Todd , Pardiñas Ulyses F. J. , Tucker Abigail S. , Ortiz Pablo E. , Charles Cyril , Viriot Laurent , Herz Joachim , Sharpe Paul T.
Published: December 2009

Changes in tooth shape have played a major role in vertebrate evolution with modification of dentition allowing an organism to adapt to new feeding strategies. The current view is that molar teeth evolved from simple conical teeth, similar to canines, by progressive addition of extra “cones” to form progressively complex multicuspid crowns. Mammalian incisors, however, are neither conical nor multicuspid, and their evolution is unclear. We show that hypomorphic mutation of a cell surface receptor, Lrp4, which modulates multiple signaling pathways, produces incisors with grooved enamel surfaces that exhibit the same molecular characteristics as the tips of molar cusps. Mice with a null mutation ofLrp4develop extra cusps on molars and have incisors that exhibit clear molar-like cusp and root morphologies. Molecular analysis identifies misregulation of Shh and Bmp signaling in the mutant incisors and suggests an uncoupling of the processes of tooth shape determination and morphogenesis. Incisors thus possess a developmentally suppressed, cuspid crown-like morphogenesis program similar to that in molars that is revealed by loss of Lrp4 activity. Several mammalian species naturally possess multicuspid incisors, suggesting that mammals have the capacity to form multicuspid teeth regardless of location in the oral jaw. Localized loss of enamel may thus have been an intermediary step in the evolution of cusps, both of which useLrp4-mediated signaling.
DNA–DNA interactions in bacteriophage capsids are responsible for the observed DNA knotting
Authors: Marenduzzo Davide , Orlandini Enzo , Stasiak Andrzej , Sumners De Witt , Tubiana Luca , Micheletti Cristian
Published: December 2009

Recent experiments showed that the linear double-stranded DNA in bacteriophage capsids is both highly knotted and neatly structured. What is the physical basis of this organization? Here we show evidence from stochastic simulation techniques that suggests that a key element is the tendency of contacting DNA strands to order, as in cholesteric liquid crystals. This interaction favors their preferential juxtaposition at a small twist angle, thus promoting an approximately nematic (and apolar) local order. The ordering effect dramatically impacts the geometry and topology of DNA inside phages. Accounting for this local potential allows us to reproduce the main experimental data on DNA organization in phages, including the cryo-EM observations and detailed features of the spectrum of DNA knots formed inside viral capsids. The DNA knots we observe are strongly delocalized and, intriguingly, this is shown not to interfere with genome ejection out of the phage.
Overfishing reduces resilience of kelp beds to climate-driven catastrophic phase shift
Authors: Ling S. D. , Johnson C. R. , Frusher S. D. , Ridgway K. R.
Published: December 2009

A key consideration in assessing impacts of climate change is the possibility of synergistic effects with other human-induced stressors. In the ocean realm, climate change and overfishing pose two of the greatest challenges to the structure and functioning of marine ecosystems. In eastern Tasmania, temperate coastal waters are warming at approximately four times the global ocean warming average, representing the fastest rate of warming in the Southern Hemisphere. This has driven range extension of the ecologically important long-spined sea urchin (
Centrostephanus rodgersii
), which has now commenced catastrophic overgrazing of productive Tasmanian kelp beds leading to loss of biodiversity and important rocky reef ecosystem services. Coincident with the overgrazing is heavy fishing of reef-based predators including the spiny lobster
Jasus edwardsii
. By conducting experiments inside and outside Marine Protected Areas we show that fishing, by removing large predatory lobsters, has reduced the resilience of kelp beds against the climate-driven threat of the sea urchin and thus increased risk of catastrophic shift to widespread sea urchin barrens. This shows that interactions between multiple human-induced stressors can exacerbate nonlinear responses of ecosystems to climate change and limit the adaptive capacity of these systems. Management actions focused on reducing the risk of catastrophic phase shift in ecosystems are particularly urgent in the face of ongoing warming and unprecedented levels of predator removal from the world's oceans.
Impact of oral bisphenol A at reference doses on intestinal barrier function and sex differences after perinatal exposure in rats
Authors: Braniste Viorica , Jouault Aurore , Gaultier Eric , Polizzi Arnaud , Buisson-Brenac Claire , Leveque Mathilde , Martin Pascal G. , Theodorou Vassilia , Fioramonti Jean , Houdeau Eric
Published: December 2009

Bisphenol A (BPA), a chemical estrogen widely used in the food-packaging industry and baby bottles, is recovered in human fluids (0.1–10 nM). Recent studies have reported that BPA is hormonally active at low doses, emphasizing the debate of a risk for human health. Estrogen receptors are expressed in the colon, and although the major route of BPA exposure is food, the effects on gut have received no attention. We first examined the endocrine disrupting potency of BPA on colonic paracellular permeability (CPP), experimental colitis, and visceral sensitivity in ovariectomized rats orally exposed to 5 mg/kg/d BPA (i.e., the no observed adverse effect level), 50 μg/kg/d BPA (i.e., tolerable daily intake), or lower doses. BPA dose-dependently decreased basal CPP, with a half-maximal inhibitory dose of 5.2 μg/kg/d, 10-fold below the tolerable daily intake. This correlated with an increase in epithelial tight junction sealing, also observed in Caco-2 cells exposed to 10 nM BPA. When ovariectomized rats were fed with BPA at the no observed adverse effect level, the severity of colitis was reduced, whereas the same dose increased pain sensitivity to colorectal stimuli. We then examined the impact of perinatal exposure to BPA on intestinal permeability and inflammatory response in the offspring. In female rats, but not in male rats, perinatal BPA evoked a decrease of CPP in adulthood, whereas the proinflammatory response of colonic mucosa was strengthened. This study first demonstrates that the xenoestrogen BPA at reference doses influences intestinal barrier function and gut nociception. Moreover, perinatal exposure promotes the development of severe inflammation in adult female offspring only.
Long-term nutrient enrichment decouples predator and prey production
Authors: Davis John M. , Rosemond Amy D. , Eggert Susan L. , Cross Wyatt F. , Wallace J. Bruce
Published: December 2009

Increased nutrient mobilization by human activities represents one of the greatest threats to global ecosystems, but its effects on ecosystem productivity can differ depending on food web structure. When this structure facilitates efficient energy transfers to higher trophic levels, evidence from previous large-scale enrichments suggests that nutrients can stimulate the production of multiple trophic levels. Here we report results from a 5-year continuous nutrient enrichment of a forested stream that increased primary consumer production, but not predator production. Because of strong positive correlations between predator and prey production (evidence of highly efficient trophic transfers) under reference conditions, we originally predicted that nutrient enrichment would stimulate energy flow to higher trophic levels. However, enrichment decoupled this strong positive correlation and produced a nonlinear relationship between predator and prey production. By increasing the dominance of large-bodied predator-resistant prey, nutrient enrichment truncated energy flow to predators and reduced food web efficiency. This unexpected decline in food web efficiency indicates that nutrient enrichment, a ubiquitous threat to aquatic ecosystems, may have unforeseen and unpredictable effects on ecosystem structure and productivity.
A muscle-specific transgenic reporter line of the sea anemone,
Nematostella vectensis
Authors: Renfer Eduard , Amon-Hassenzahl Annette , Steinmetz Patrick R. H. , Technau Ulrich
Published: December 2009

The sea anemone,
Nematostella vectensis
, has become an attractive new model organism for comparative genomics and evolutionary developmental biology. Over the last few years, many genes have been isolated and their expression patterns studied to gain insight into their function. More recently, functional tools have been developed to manipulate gene function; however, most of these approaches rely on microinjection and are limited to early stages of development. Transgenic lines would significantly enhance the tractability of the system. In particular, the study of gene- or tissue-specific promoters would be most useful. Here we report the stable establishment of a transgenic line using the I-SceI meganuclease system to facilitate integration into the genome. We isolated a 1.6-kb fragment of the regulatory upstream region of the
Myosin Heavy Chain1
(
MyHC1
) gene and found that the transgene is specifically expressed in the retractor and tentacle muscles of
Nematostella
polyps, faithfully reproducing the expression of the endogenous
MyHC1
gene. This demonstrates that the 1.6-kb fragment contains all of the regulatory elements necessary to drive correct expression and suggests that retractor and tentacle muscles in
Nematostella
are distinct from other myoepithelial cells. The transgene is transmitted through the germline at high frequency, and G
1
transgenic polyps have only one integration site. The relatively high frequency of transgenesis, in combination with gene- or tissue-specific promoters, will foster experimental possibilities for studying in vivo gene functions in gene regulatory networks and developmental processes in the nonbilaterian sea anemone,
Nematostella vectensis
.
Nucleosome positioning by genomic excluding-energy barriers
Authors: Milani Pascale , Chevereau Guillaume , Vaillant Cédric , Audit Benjamin , Haftek-Terreau Zofia , Marilley Monique , Bouvet Philippe , Argoul Françoise , Arneodo Alain
Published: December 2009

Recent genome-wide nucleosome mappings along with bioinformatics studies have confirmed that the DNA sequence plays a more important role in the collective organization of nucleosomes in vivo than previously thought. Yet in living cells, this organization also results from the action of various external factors like DNA-binding proteins and chromatin remodelers. To decipher the code for intrinsic chromatin organization, there is thus a need for in vitro experiments to bridge the gap between computational models of nucleosome sequence preferences and in vivo nucleosome occupancy data. Here we combine atomic force microscopy in liquid and theoretical modeling to demonstrate that a major sequence signaling in vivo are high-energy barriers that locally inhibit nucleosome formation rather than favorable positioning motifs. We show that these genomic excluding-energy barriers condition the collective assembly of neighboring nucleosomes consistently with equilibrium statistical ordering principles. The analysis of two gene promoter regions in
Saccharomyces cerevisiae
and the human genome indicates that these genomic barriers direct the intrinsic nucleosome occupancy of regulatory sites, thereby contributing to gene expression regulation.
Effective collaboration between marginal metallophilic macrophages and CD8+dendritic cells in the generation of cytotoxic T cells
Authors: Backer Ronald , Schwandt Timo , Greuter Mascha , Oosting Marije , Jüngerkes Frank , Tüting Thomas , Boon Louis , O’Toole Tom , Kraal Georg , Limmer Andreas , den Haan Joke M. M.
Published: December 2009

The spleen is the lymphoid organ that induces immune responses toward blood-borne pathogens. Specialized macrophages in the splenic marginal zone are strategically positioned to phagocytose pathogens and cell debris, but are not known to play a role in the activation of T-cell responses. Here we demonstrate that splenic marginal metallophilic macrophages (MMM) are essential for cross-presentation of blood-borne antigens by splenic dendritic cells (DCs). Our data demonstrate that antigens targeted to MMM as well as blood-borne adenoviruses are efficiently captured by MMM and exclusively transferred to splenic CD8+DCs for cross-presentation and for the activation of cytotoxic T lymphocytes. Depletion of macrophages in the marginal zone prevents cytotoxic T-lymphocyte activation by CD8+DCs after antibody targeting or adenovirus infection. Moreover, we show that tumor antigen targeting to MMM is very effective as antitumor immunotherapy. Our studies point to an important role for splenic MMM in the initial steps of CD8+T-cell immunity by capturing and concentrating blood-borne antigens and the transfer to cross-presenting DCs which can be used to design vaccination strategies to induce antitumor cytotoxic T-cell immunity.
A genomewide study identifies the Wnt signaling pathway as a major target of p53 in murine embryonic stem cells
Authors: Lee Kyoung-Hwa , Li Mangmang , Michalowski Aleksandra M. , Zhang Xinyue , Liao Hongling , Chen Lingyi , Xu Yang , Wu Xiaolin , Huang Jing
Published: December 2009

Both p53 and the Wnt signaling pathway play important roles in regulating the differentiation of mouse embryonic stem cells (mESCs). However, it is not known whether they directly and/or functionally crosstalk in mESCs. Here we report a surprising antidifferentiation function of p53 in mESCs through directly regulating the Wnt signaling pathway. A chromatin-immunoprecipitation-based microarray (ChIP-chip) and gene expression microarray assays reveal that the Wnt signaling pathway is significantly (
P
value, 0.000048) overrepresented in p53-regulated genes in mESCs. The expression of five Wnt ligand genes is robustly induced by various genotoxic and nongenotoxic insults in a p53-dependent manner. Moreover, the induction of these Wnt genes is greatly attenuated in mouse embryonic fibroblast (MEF) cells and ESC-derived neural stem/progenitor cells, suggesting that the induction is mESC specific. It is established that the activation of the Wnt signaling pathway inhibits the differentiation of mESCs. Consistent with this notion, we detected an antidifferentiation activity from the conditioned medium (CM) collected from UV (UV)-treated mESCs. This antidifferentiation activity can be lowered by either the addition of Wnt antagonists into the CM or the reduction of p53 levels in UV-treated mESCs. Therefore, reminiscent of its dual functions on death and survival in somatic cells, p53 appears to regulate both prodifferentiation and antidifferentiation programs in mESCs. Our findings uncover a direct and functional connection between p53 and the Wnt signaling pathway, and expand the catalog of p53 regulated genes in mESCs.
Plant flotillins are required for infection by nitrogen-fixing bacteria
Authors: Haney Cara H. , Long Sharon R.
Published: December 2009

To establish compatible rhizobial-legume symbioses, plant roots support bacterial infection via host-derived infection threads (ITs). Here, we report the requirement of plant flotillin-like genes (
FLOT
s) in
Sinorhizobium meliloti
infection of its host legume
Medicago truncatula
. Flotillins in other organisms have roles in viral pathogenesis, endocytosis, and membrane shaping. We identified seven
FLOT
genes in the
M. truncatula
genome and show that two,
FLOT2
and
FLOT4
, are strongly up-regulated during early symbiotic events. This up-regulation depends on bacterial Nod Factor and the plant's ability to perceive Nod Factor. Microscopy data suggest that
M. truncatula
FLOT2 and FLOT4 localize to membrane microdomains. Upon rhizobial inoculation, FLOT4 uniquely becomes localized to the tips of elongating root hairs. Silencing
FLOT2
and
FLOT4
gene expression reveals a nonredundant requirement for both genes in IT initiation and nodule formation.
FLOT4
is uniquely required for IT elongation, and FLOT4 localizes to IT membranes. This work reveals a critical role for plant flotillins in symbiotic bacterial infection.
Chloroplast acetyl-CoA carboxylase activity is 2-oxoglutarate–regulated by interaction of PII with the biotin carboxyl carrier subunit
Authors: Feria Bourrellier Ana Belen , Valot Benoit , Guillot Alain , Ambard-Bretteville Françoise , Vidal Jean , Hodges Michael
Published: December 2009

The PII protein is a signal integrator involved in the regulation of nitrogen metabolism in bacteria and plants. Upon sensing of cellular carbon and energy availability, PII conveys the signal by interacting with target proteins, thereby modulating their biological activity. Plant PII is located to plastids; therefore, to identify new PII target proteins, PII-affinity chromatography of soluble extracts from
Arabidopsis
leaf chloroplasts was performed. Several proteins were retained only when Mg-ATP was present in the binding medium and they were specifically released from the resin by application of a 2-oxoglutarate-containing elution buffer. Mass spectroscopy of SDS/PAGE-resolved protein bands identified the biotin carboxyl carrier protein subunits of the plastidial acetyl-CoA carboxylase (ACCase) and three other proteins containing a similar biotin/lipoyl-binding motif as putative PII targets. ACCase is a key enzyme initiating the synthesis of fatty acids in plastids. In in vitro reconstituted assays supplemented with exogenous ATP, recombinant
Arabidopsis
PII inhibited chloroplastic ACCase activity, and this was completely reversed in the presence of 2-oxoglutarate, pyruvate, or oxaloacetate. The inhibitory effect was PII-dose-dependent and appeared to be PII-specific because ACCase activity was not altered in the presence of other tested proteins. PII decreased the
V
max
of the ACCase reaction without altering the
K
m
for acetyl-CoA. These data show that PII function has evolved between bacterial and plant systems to control the carbon metabolism pathway of fatty acid synthesis in plastids.
Bicarbonate-sensing soluble adenylyl cyclase is an essential sensor for acid/base homeostasis
Authors: Tresguerres Martin , Parks Scott K. , Salazar Eric , Levin Lonny R. , Goss Greg G. , Buck Jochen
Published: December 2009

pH homeostasis is essential for life, yet it remains unclear how animals sense their systemic acid/base (A/B) status. Soluble adenylyl cyclase (sAC) is an evolutionary conserved signaling enzyme that produces the second messenger cAMP in response to bicarbonate ions (HCO3−). We cloned the sAC ortholog from the dogfish, a shark that regulates blood A/B by absorbing and secreting protons (H+) and HCO3−at its gills. Similar to mammalian sAC, dogfish soluble adenylyl cyclase (dfsAC) is activated by HCO3−and can be inhibited by two structurally and mechanistically distinct small molecule inhibitors. dfsAC is expressed in the gill epithelium, where the subset of base-secreting cells resides. Injection of inhibitors into animals under alkaline stress confirmed that dfsAC is essential for maintaining systemic pH and HCO3−levels in the whole organism. One of the downstream effects of dfsAC is to promote the insertion of vacuolar proton pumps into the basolateral membrane to absorb H+into the blood. sAC orthologs are present throughout metazoans, and mammalian sAC is expressed in A/B regulatory organs, suggesting that systemic A/B sensing via sAC is widespread in the animal kingdom.
PGC-1α negatively regulates hepatic FGF21 expression by modulating the heme/Rev-Erbα axis
Authors: Estall Jennifer L. , Ruas Jorge L. , Choi Cheol Soo , Laznik Dina , Badman Michael , Maratos-Flier Eleftheria , Shulman Gerald I. , Spiegelman Bruce M.
Published: December 2009

FGF21 is a hormone produced in liver and fat that dramatically improves peripheral insulin sensitivity and lipid metabolism. We show here that obese mice with genetically reduced levels of a key hepatic transcriptional coactivator, PGC-1α, have improved whole-body insulin sensitivity with increased levels of hepatic and circulating FGF21. Gain- and loss-of-function studies in primary mouse hepatocytes show that hepatic FGF21 levels are regulated by the expression of PGC-1α. Importantly, PGC-1α-mediated reduction of
FGF21
expression is dependent on Rev-Erbα and the expression of ALAS-1.
ALAS-1
is a PGC-1α target gene and the rate-limiting enzyme in the synthesis of heme, a ligand for Rev-Erbα. Modulation of intracellular heme levels mimics the effect of PGC-1α on
FGF21
expression, and inhibition of heme biosynthesis completely abrogates the down-regulation of
FGF21
in response to PGC-1α. Thus, PGC-1α can impact hepatic and systemic metabolism by regulating the levels of a nuclear receptor ligand.
Identification of
MIR390a
precursor processing-defective mutants in Arabidopsis by direct genome sequencing
Authors: Cuperus Josh T. , Montgomery Taiowa A. , Fahlgren Noah , Burke Russell T. , Townsend Tiffany , Sullivan Christopher M. , Carrington James C.
Published: December 2009

Transacting siRNA (tasiRNA) biogenesis in Arabidopsis is initiated by microRNA (miRNA) –guided cleavage of primary transcripts. In the case of
TAS3
tasiRNA formation, ARGONAUTE7 (AGO7)–miR390 complexes interact with primary transcripts at two sites, resulting in recruitment of RNA-DEPENDENT RNA POLYMERASE6 for dsRNA biosynthesis. An extensive screen for Arabidopsis mutants with specific defects in
TAS3
tasiRNA biogenesis or function was done. This yielded numerous
ago7
mutants, one
dcl4
mutant, and two mutants that accumulated low levels of miR390. A direct genome sequencing-based approach to both map and rapidly identify one of the latter mutant alleles was developed. This revealed a G-to-A point mutation (
mir390a-1
) that was calculated to stabilize a relatively nonpaired region near the base of the
MIR390a
foldback, resulting in misprocessing of the miR390/miR390* duplex and subsequent reduced
TAS3
tasiRNA levels. Directed substitutions, as well as analysis of variation at paralogous miR390-generating loci (
MIR390a
and
MIR390b
), indicated that base pair properties and nucleotide identity within a region 4–6 bases below the miR390/miR390* duplex region contributed to the efficiency and accuracy of precursor processing.
Joint Book Reading across Cultures: A Comparison of Surinamese-Dutch, Turkish-Dutch, and Dutch Parent-Child Dyads
Authors: Bus Adriana G. , Leseman Paul P.M. , Keultjes Petra
Published: December 2009

This article reports about in-depth analyses of how parents from different cultural groups mediated a simple narrative text to their 4-year-old children. The sample included 19 Surinamese-Dutch, 19 Turkish-Dutch, and 19 Dutch low-SES dyads. The sessions videotaped in the families' homes were transcribed and coded with a detailed behavioral coding system that maps the function and content of parent and child behaviors. In addition, the sessions were rated on four 7-point scales for how parents interacted with their children in terms of supportive presence. Overall the study supports the hypothesis that when reading is less important for the parents personally, they are less inclined to deviate from the text in order to negotiate meaning. Their children initiated more interactions than other children did, but low-cognitive-demand behaviors such as naming details or identifying pictures of characters characterized these interactions. The ethnic groups also differed in how parents interacted with their children, but these characteristics of the reading session were not related to parental literacy.
Critical Issues: Limits of Identification: The Personal, Pleasurable, and Critical in Reader Response
Authors: Lewis Cynthia
Published: December 2009

In this article, I argue that the most common use of reader-response theory in the classroom is misguided in its emphasis on personal response and identification. After reconsidering the meaning of the “aesthetic stance” as defined in the work of Louise Rosenblatt, I discuss the social and political nature of readers, texts, and contexts. I include two examples of teachers talking about a work of children's literature to illustrate that when a text is about characters whose cultures and life worlds are very different from the reader's, disrupting the reader's inclination to identify with the text can heighten the reader's self consciousness and text consciousness. This stance should not be viewed as less aesthetic than a more direct or immediate relationship between reader and text. Finally, I argue for a broader view of what aesthetic reading can mean, one that addresses the social and political dimensions of texts and invites students to take pleasure in both the personal and the critical.
Critical Issues: Researching Complexity
Authors: Sumara Dennis J.
Published: December 2009

This essay suggests that recent developments in Complexity Theory have the potential to offer new insights to reader-response researchers. Presented as a rubric that collects theoretical understandings from a number of domains such as ecology, biology, neurology, immunology, psychology, education, sociology, economics, anthropology, & evolutionary theory, Complexity Theory is developed as an antidote to Enlightenment beliefs about Reason and the separation of knowledge from knowers. In addition to providing a brief discussion of what Complexity Theory suggests about mind, selfhood, intelligence, and practices of reading, the essay offers a brief discussion of the import of these reconceptualizations to reader-response researchers. It is concluded that developing more complex reader-response research practices will require both universities and university researchers to develop new commitments and practices.
Finnish Kindergartners' Literacy Development in Contextualized Literacy Episodes: A Focus on Spelling
Authors: Korkeamäki Riitta-Liisa , Dreher Mariam Jean
Published: December 2009

This study focused on children's spelling development in a Finnish kindergarten. We examined how and when spelling begins when children are provided guided and meaningful literacy opportunities. Field notes, children's writing samples, and four dictations, as well as pre- and postinstruction assessment of literacy-related tasks were analyzed to describe children's progress and strategies. At the start of the study, some children did not know any letters, while others who knew some letters did not necessarily use them in the first dictation, drawing instead. Classroom activities offered children opportunities to increase letter knowledge and demonstrated how to apply that knowledge. The assessment at the end of the study in Phase 1 demonstrated a substantial growth in children's spelling: some children spelled almost all the dictated words correctly, most of the children used invented spelling, and only one child used random letter strings for a few words. In addition, children's reading developedso that several children were alphabetic-phase readers. In Phase 2, all the children used alphabetic strategies.
Audience Awareness in a Technology-Rich Elementary Classroom
Authors: Baker Elizabeth A. , Rozendal Mary S. , Whitenack Joy W.
Published: December 2009

We examined audience awareness in a 5-month naturalistic study of a fourth-grade classroom infused with technology. All students had a computer on their desks, and five multimedia workstations with Web access were available in the classroom. We found that this technology-rich classroom, which also valued collaboration and inquiry, offered such pervasive opportunities for interaction between authors and classmates that it was difficult to distinguish between author and audience. We propose interactive audience as an expanded conception of audience awareness, and we examine the impact that interactive audience had on authors and their composition.
Dimensions and Predictors of Literary Response
Authors: van Schooten Erik , Oostdam Ron , de Glopper Kees
Published: December 2009

To test the validity of the Literary Response Questionnaire (lrq, Miall & Kuiken, 1995b) and to assess its relationships with student, home-background, and school-related variables, the lrq was administered to Dutch students in grades 7, 8, and 9. The seven first-order factors of the lrq, as identified by Miall and Kuiken {1995b), were confirmed. One of the two second-order factors was not identified. However, a model with two different second-order factors fitted the data. Trance, the first factor, represents the degree to which a reader is absorbed in a story. Literary Interpretation, the second factor, represents the degree to which a reader likes or dislikes literary criticism and reflection on the meaning of what is read. Grade, gender, type of education, vocabulary size, reading behavior, and cultural level of the home environment were the best predictors of the literary response scores. Results are discussed in relation to response theories and research and to literary education.
Carmen Montana, the General Education Diploma, and her Social Network
Authors: Dowdy J. Kilgour
Published: December 2009

This case study focuses on the experience of a Black woman who returned to school for her General Education Diploma (ged) certificate after 32 years away from formal schooling. Through the reflections of Montana and her social network, six women who supported her during and after the ged exam, we are able to see the way in which Montana changes the network and herself over time. We are also able to see some of the ways in which Montana positively affects her children and husband through her pursuit of the ged. The 11 interviews reveal the themes of improved literacy skills, heightened confidence, community activism, and youth leadership, as Montana circulates in her community and congregation a year after the ged. It is also possible to glean from the study the kind of opportunities that adult literacy educators may create by involving a students social network in the active support of increased literacy skills at the ged level.
Critical Issues: Democracy, Community, Self, Literacy, and the Value of Global Conversation
Authors: Meredith Kurtis S. , Steele Jeannie L. , Kikušová Sona
Published: December 2009

In this article, we begin by describing how literacy is placed within a social and, consequently, political context and how the present predominant conceptualization of literacy necessarily insinuates a democratic context. We outline a philosophical basis for linking education and democracy by briefly defining the construction of self, community, and citizenship before returning to articulate the link between education, literacy, and democracy. The international community is engaged in this conversation, and in the context of globalization, it is suggested that such a conversation may be critical to community survival. Essential to meaningful discussion of critical literacy is reference to a means for practical responses to the literature itself. A model practical application of the theoretical construct presented here is briefly described.
Speaking But not Being Heard: Two Adolescents Negotiate Classroom Talk about Text
Authors: Hinchman Kathleen A. , Young Josephine Peyton
Published: December 2009

This article is a critical discourse analysis that explored how two students participated in classroom talk about written text. We analyzed field notes and transcripts from classroom videotapes and student interviews according to three dimensions, description, interpretation, and explanation, and with concern for three contexts, situational, institutional, and societal. The students participated in talk in complicated, devolving ways over 1 school year - ways that seemed tied to a variety of social constructions inside and outside the classroom. One participated in classroom talk about text with an assumption of expertise, only to lose credibility when his teacher expected richer interpretive insights. The other participated in such talk from an assumption of equality, yet no one listened to what she said until it diverged from the supportable, in which case they derided her. Our analysis suggests that we should be vigilant in our setup and monitoring of individuals' participation in classroom talk, about text and otherwise, looking to disrupt ways it is embedded with hurtful institutional and societal discourses. Such attention may help us to develop more equitable literacy pedagogy.
Profiling Persuasion: The Role of Beliefs, Knowledge, and Interest in the Processing of Persuasive Texts That Vary by Argument Structure
Authors: Buehl Michelle M. , Alexander Patricia A. , Murphy P. Karen , Sperl Christopher T.
Published: December 2009

Undergrauate participants read both a one-sided text on educational reform and a two-sided nonrefutational text on the V-Chip. Students completed topic-specific beliefs, knowledge, and interest measures and reacted to specific text characteristics. The results indicated that although both forms of text affected readers, the effects varied by the type of argument structure. Specifically, after adjusting for topic, the one-sided text was more effective in changing readers' beliefs than the two-sided nonrefutational text, whereas the two-sided nonrefutational article was more effective in changing participants' knowledge. The knowledge and interest profiles of more or less persuaded readers differed significantly for the two-sided nonrefutational text but not for the one-sided text. Readers' reactions to the articles also differed by argument structure. Overall, this study contributes to the understanding of readers' processing of one-sided and two-sided nonrefutational texts.
“I Can't Wait to See Carlos!”: Preservice Teachers, Situated Learning, and Personal Relationships with Students
Authors: Worthy Jo , Patterson Elizabeth
Published: December 2009

In this study, we examined the reflections of 71 preservice teachers as they tutored literacy in a predominantly Hispanic American, low-income school. The carefully structured, intensively supervised practicum for each preservice teacher combined situated learning with guided critical reflection in the context of a relationship with one elementary student. Working within the framework of caring and its influence on socially mediated learning, we also explored the nature of personal relationships. Judging from their reflections, the experience of working one-on-one with a student positively influenced preservice teachers' content and procedural knowledge and self-confidence as teachers. Although not all relationships were easy to establish, the tutors' strong emotional ties with students resulted in their increased personal satisfaction, learning about teaching, and feelings of responsibility for their child's learning. Further, as tutors got to know their students, many rejected deficit notions and labels like “slow learner,” “limited-English proficient,” and “at risk” and came to regard their students as unique, valuable individuals.
The Parent-Child Relationship during Beginning Reading
Authors: Bergin Christi
Published: December 2009

This article addresses the affective quality of the parent-child relationship during shared book reading with kindergarten and first-grade children. Research has emphasized the frequency, rather than quality, of parent-child reading with beginning readers. However, frequent shared reading may not be beneficial if parents are hostile and critical as their child struggles to read. Thirty-two parent-child dyads were videotaped reading to each other. Interaction was coded for several affective dimensions: praise, hostility, criticism, support, positive affect, emotional spontaneity, physical proximity, and affection. manova analyses indicated that there was a significant difference in the affective quality of the parent-child relationship related to both the child's attitude toward readingand the child's reading fluency. Dyads who were affectionate during shared reading had children who were less frustrated with and more engaged in reading and who read more words per minute earlier, than less affectionate dyads. Educators may need to help parents make joint reading a pleasurable experience rather than just encouraging them to engage in more frequent joint book reading.
The Importance of Memory and Integration Factors to Oral Reading Ability
Authors: Rodenborn Leo V.
Published: December 2009

One-hundred and eighty randomly selected elementary school students, stratified to include an equal number of boys and girls at each of the six levels and each scoring within 1 SD for the total IQ Mental Maturity, were tested to gain an estimate of the reliability of the three constructed tests (in the areas of auditory memory, visual and auditory-visual integration [AVI]). Findings of the study highlighted the value of mental age as a predictor of reading achievement. Mental age-was found to be (I) linearly related to AVI and (2) a predictor of reading achievement whose efficiency is not increased considerably by the addition of selected auditory factors.
A Schema for the Classification of Conceptual Frameworks Involving Reading
Authors: Emans Robert
Published: December 2009

Presents a schema for classifying conceptual frameworks involving reading. The schema classifies conceptual frameworks according to type, content, and frame of reference. The types of conceptual frameworks are taxonomy, visual representation, and mathematical description. The content of conceptual frameworks include reading process, reading aptitude, and the learning-to-read process. The frame of reference dimension involves properties related to reading such as language, learning, and intellect from the areas of physiology, psychology, and psycholinguistics. The importance of developing frameworks from the various intersects of the schema is shown.
An Evaluation of a Summer Reading Improvement Course for Disadvantaged High School Students
Authors: Gwaltney Wayne K.
Published: December 2009

Purposes of this investigation were to evaluate a seven-weeks reading improvement course and to analyze various correlates of reading achievement using disadvantaged high school students as subjects. Sixty students were randomly assigned to one of two groups: experimental (enrolled in course) or control (no reading instruction).

Analysis of covariance results suggested that the reading improvement course was not effective in raising post-test reading achievement scores. Among those variables studied listening comprehension appeared to be the best correlate of reading achievement. Other variables considered were intelligence, total personality adjustment, achievement motivation, and endurance.
Visual Perception and Self-Concept: New Directions in Reading
Authors: Fillmer H. T. , Busby Walter A. , Smittle Patricia
Published: December 2009

This study investigated the relationship between reading achievement, self-concept and visual perception of 100 randomly selected junior high school pupils. Findings indicatd that: (1) both two- and three-dimensional perception had significant relationships with reading at the .001 level; (2) a significant relationship existed between reading and two of the self-concept components; and (3) there was a significant relationship between two-dimensional perception and eight of the self-concept components. Investigators concluded that there is a significant relationship between self-concept and reading and hypothesized that in some instances reading disability might well be a conditioned attitude. It was recommended that further investigations be designed to explore the causal relationship between self-concept, perception and reading.
The Measurement of Reading Speed and the Obligation to Generalize to a Population of Reading Materials
Authors: Miller Gerald R. , Coleman Edmund B.
Published: December 2009

Although most studies of reading behavior have little scientific value if their conclusions have to be restricted to the specific materials that were used in the experiment, reading researchers have seldom used designs that would enable them to generalize beyond the particular letters, words, sentences, and so on they chanced to use. Data from an experiment by Carver are used to show that it is therefore likely that many experiments could not be replicated if different samples of materials were drawn. Evidence is also given that reading speed, if measured in a fine-grained unit such as letters per second, does not increase as passages become more difficult, but is a constant across a range that extends from first-grade texts to technical prose.