bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing the Communicative Participation Item Bank: Rasch Analysis Results From a Spasmodic Dysphonia Sample
Authors: Baylor Carolyn R. , Yorkston Kathryn M. , Eadie Tanya L. , Miller Robert M. , Amtmann Dagmar
Published: August 2009

Purpose

The purpose of this study was to conduct the initial psychometric analyses of the Communicative Participation Item Bank—a new self-report instrument designed to measure the extent to which communication disorders interfere with communicative participation. This item bank is intended for community-dwelling adults across a range of communication disorders.

Method

A set of 141 candidate items was administered to 208 adults with spasmodic dysphonia. Participants rated the extent to which their condition interfered with participation in various speaking communication situations. Questionnaires were administered online or in a paper version per participant preference. Participants also completed the Voice Handicap Index (B. H. Jacobson et al., 1997) and a demographic questionnaire. Rasch analyses were conducted using Winsteps software (J. M. Linacre, 1991).

Results

The results show that items functioned better when the 5-category response format was recoded to a 4-category format. After removing 8 items that did not fit the Rasch model, the remaining 133 items demonstrated strong evidence of sufficient unidimensionality, with the model accounting for 89.3% of variance. Item location values ranged from −2.73 to 2.20 logits.

Conclusions

Preliminary Rasch analyses of the Communicative Participation Item Bank show strong psychometric properties. Further testing in populations with other communication disorders is needed.
Mandibular Motor Control During the Early Development of Speech and Nonspeech Behaviors
Authors: Steeve Roger W. , Moore Christopher A.
Published: August 2009

Purpose

The mandible is often portrayed as a primary structure of early babble production, but empiricists still need to specify (a) how mandibular motor control and kinematics vary among different types of multisyllabic babble, (b) whether chewing or jaw oscillation relies on a coordinative infrastructure that can be exploited for early types of multisyllables, and (c) whether the organization of motor control and associated kinematics varies across the nonspeech behaviors that are candidate motor stereotypies for speech.

Method

Electromyographic signals were obtained from mandibular muscle groups, and associated kinematics were measured longitudinally from a typically developing infant from 9 to 22 months during jaw oscillation, chewing, and several types of early multisyllabic babble.

Results

Measures of early motor control and mandibular kinematics for multisyllabic productions indicated task-dependent changes across syllable types and significant differences across babble and nonspeech behaviors. Differences in motor control were also observed across nonspeech behaviors.

Conclusions

Motor control for babble appears to be influenced by the balanced interaction between developing motor and linguistic systems, such that variation in linguistic complexity systematically evinces changes in motor organization apparently to meet these demands. This same effect was noted among chewing and jaw oscillation; task-dependent changes in mandibular control were noted across behaviors.
Nonparticipatory Stiffness in the Male Perioral Complex
Authors: Chu Shin-Ying , Barlow Steven M. , Lee Jaehoon
Published: August 2009

Purpose

The objective of this study was to extend previous published findings in the authors' laboratory using a new automated technology to quantitatively characterize nonparticipatory perioral stiffness in healthy male adults.

Method

Quantitative measures of perioral stiffness were sampled during a nonparticipatory task using a computer-controlled linear servo motor to impose a series of tensile displacements over a span of approximately 24 mm at the oral angle in 20 healthy young male adults. Perioral electromyograms were simultaneously sampled to confirm nonparticipation or passive muscle state. Perioral stiffness, derived as a quotient from resultant force (ΔF) and oral span (ΔX), was modeled with regression techniques and subsequently compared to previously reported perioral stiffness data for female adults.

Results

Multilevel regression analysis revealed a significant quadratic relation between the perioral stiffness and interangle span; however, no significant difference was found between adult males and females.

Conclusion

These normative measures will have application to future studies designed to objectively assess the effects of pathology (i.e., progressive neuromotor disease, traumatic brain insult) and intervention (pharmacologic, neurosurgical, and reconstructive surgery of the face [i.e., cleft lip, trauma, missile injuries]) on facial animation and speech kinematics.
Somatosensory Gating Is Dependent on the Rate of Force Recruitment in the Human Orofacial System
Authors: Andreatta Richard D. , Barlow Steven M.
Published: August 2009

Purpose

Functional orofacial behaviors vary in their force endpoint and rate of recruitment. This study assessed the gating of orofacial cutaneous somatosensation during different cyclic lip force recruitment rates. Understanding how differences in the rate of force recruitment influences trigeminal system function is an important step toward furthering the knowledge of orofacial sensorimotor control.

Method

Lower lip vibrotactile detection thresholds (LL-VDTs) were sampled in response to sinusoidal inputs delivered to the lip vermilion at 5, 10, 50, and 150 Hz while adult participants engaged in a baseline condition (no force), 2 low-level lip force recruitment tasks differing by rate (0.1 Hz or 2 Hz), and passive displacement of the lip as a control to approximate the mechanosensory consequences of voluntary movement.

Results

LL-VDTs increased significantly for test frequencies at or below 50 Hz during voluntary lip force recruitment. LL-VDT shifts were positively related to changes in the rate of lip force recruitment, whereas passively imposed displacements of the lip were ineffective in shifting LL-VDTs.

Conclusions

These findings are considered in relation to published reports of force-related sensory gating in orofacial and limb systems and the potential role of somatosensory gating along the trigeminal system during orofacial behaviors.
Lipreading, Processing Speed, and Working Memory in Younger and Older Adults
Authors: Feld Julia E. , Sommers Mitchell S.
Published: August 2009

Purpose

To examine several cognitive and perceptual abilities—including working memory (WM), information processing speed (PS), perceptual closure, and perceptual disembedding skill—as factors contributing to individual differences in lipreading performance and to examine how patterns in predictor variables change across age groups.

Method

Forty-three younger adults (mean age = 20.8 years,
SD
= 2.4) and 38 older adults (mean age = 76.8 years,
SD
= 5.6) completed tasks measuring lipreading ability, verbal WM, spatial WM (SWM), PS, and perceptual abilities.

Results

Younger adults demonstrated superior lipreading ability and perceptual skills compared with older adults. In addition, younger participants exhibited longer WM spans and faster PS than did the older participants. SWM and PS accounted for a significant proportion of the variance in lipreading ability in both younger and older adults, and the pattern of predictor variables remained consistent over age groups.

Conclusions

These findings suggest that the large individual variability in lipreading ability can be explained, in part, by individual differences in SWM and PS. Furthermore, as both of these abilities are known to decline with age, the findings suggest that age-related impairments in either or both of these abilities may account for the poorer lipreading ability of older compared with younger adults.
Quantifying Speech Rhythm Abnormalities in the Dysarthrias
Authors: Liss Julie M. , White Laurence , Mattys Sven L. , Lansford Kaitlin , Lotto Andrew J. , Spitzer Stephanie M. , Caviness John N.
Published: August 2009

Purpose

In this study, the authors examined whether rhythm metrics capable of distinguishing languages with high and low temporal stress contrast also can distinguish among control and dysarthric speakers of American English with perceptually distinct rhythm patterns.

Methods

Acoustic measures of vocalic and consonantal segment durations were obtained for speech samples from 55 speakers across 5 groups (hypokinetic, hyperkinetic, flaccid-spastic, ataxic dysarthrias, and controls). Segment durations were used to calculate standard and new rhythm metrics. Discriminant function analyses (DFAs) were used to determine which sets of predictor variables (rhythm metrics) best discriminated between groups (control vs. dysarthrias; and among the 4 dysarthrias). A cross-validation method was used to test the robustness of each original DFA.

Results

The majority of classification functions were more than 80% successful in classifying speakers into their appropriate group. New metrics that combined successive vocalic and consonantal segments emerged as important predictor variables. DFAs pitting each dysarthria group against the combined others resulted in unique constellations of predictor variables that yielded high levels of classification accuracy.

Conclusions

This study confirms the ability of rhythm metrics to distinguish control speech from dysarthrias and to discriminate dysarthria subtypes. Rhythm metrics show promise for use as a rational and objective clinical tool.
Phonological Awareness and Types of Sound Errors in Preschoolers With Speech Sound Disorders
Authors: Preston Jonathan , Edwards Mary Louise
Published: August 2009

Purpose

Some children with speech sound disorders (SSD) have difficulty with literacy-related skills, particularly phonological awareness (PA). This study investigates the PA skills of preschoolers with SSD by using a regression model to evaluate the degree to which PA can be concurrently predicted by types of speech sound errors.

Method

Preschoolers with SSD (
n
= 43) participated in PA and speech sound production assessment. Errors from a 125-item picture naming task were coded in 2 ways: (a) considering all consonant errors equally (percentage of consonants correct [PCC]) and (b) using a 3-category system that captures component features of sound errors (typical sound changes, atypical sound changes, and distortions). PA tasks included rhyme matching, onset matching, onset segmentation and matching, and blending.

Results

Variance in a PA composite score could be predicted partly by vocabulary and age (33%). Atypical sound changes accounted for an additional 6% of variance in PA, but distortions and typical errors did not account for significant variance. When the same consonant errors were analyzed using PCC, speech errors did not predict significant variance in PA.

Conclusions

Poorer PA is associated with lower receptive vocabularies and more atypical sound errors. Results are interpreted in the context of the accuracy of phonological representations.
Layering of [BMIM]+-based ionic liquids at a charged sapphire interface
Authors: Mezger Markus , Schramm Sebastian , Schröder Heiko , Reichert Harald , Deutsch Moshe , De Souza Emerson J. , Okasinski John S. , Ocko Benjamin M. , Honkimäki Veijo , Dosch Helmut
Published: September 2009

The structure of two model room temperature ionic liquids, [BMIM]+[PF6]− and [BMIM]+[BF4]−, near the solid/liquid interface with charged Al2O3(0001) (sapphire) was determined with subnanometer resolution by high energy (72.5 keV) x-ray reflectivity. [BMIM]+[PF6]− exhibits alternately charged, exponentially decaying, near-surface layering. By contrast, the smaller-anion compound, [BMIM]+[BF4]−, shows only a single layer of enhanced electron density at the interface. The different layering behaviors, and their characteristic length scales, correspond well to the different bulk diffraction patterns, also measured in this study. Complementary measurements of the surface and interface energies showed no significant different between the two RTILs. The combined bulk-interface results support the conclusion that the interfacial ordering is dominated by the same electrostatic ion-ion interactions dominating the bulk correlations, with hydrogen bonding and dispersion interactions playing only a minor role.
Diffusion of a sphere in a dilute solution of polymer coils
Authors: Krüger Matthias , Rauscher Markus
Published: September 2009

We calculate the short time and the long time diffusion coefficients of a spherical tracer particle in a polymer solution in the low density limit by solving the Smoluchowski equation for a two-particle system and applying a generalized Einstein relation (fluctuation dissipation theorem). The tracer particle as well as the polymer coils are idealized as hard spheres with a no-slip boundary condition for the solvent but the hydrodynamic radius of the polymer coils is allowed to be smaller than the direct-interaction radius. We take hydrodynamic interactions up to 11th order in the particle distance into account. For the limit of small polymers, the expected generalized Stokes–Einstein relation is found. The long time diffusion coefficient also roughly obeys the generalized Stokes–Einstein relation for larger polymers whereas the short time coefficient does not. We find good qualitative and quantitative agreement to experiments.
Additional evidence on the use of personal ornaments in the Middle Paleolithic of North Africa
Authors: d'Errico Francesco , Vanhaeren Marian , Barton Nick , Bouzouggar Abdeljalil , Mienis Henk , Richter Daniel , Hublin Jean-Jacques , McPherron Shannon P. , Lozouet Pierre
Published: August 2009

Recent investigations into the origins of symbolism indicate that personal ornaments in the form of perforated marine shell beads were used in the Near East, North Africa, and SubSaharan Africa at least 35 ka earlier than any personal ornaments in Europe. Together with instances of pigment use, engravings, and formal bone tools, personal ornaments are used to support an early emergence of behavioral modernity in Africa, associated with the origin of our species and significantly predating the timing for its dispersal out of Africa. Criticisms have been leveled at the low numbers of recovered shells, the lack of secure dating evidence, and the fact that documented examples were not deliberately shaped. In this paper, we report on 25 additional shell beads from four Moroccan Middle Paleolithic sites. We review their stratigraphic and chronological contexts and address the issue of these shells having been deliberately modified and used. We detail the results of comparative analyses of modern, fossil, and archaeological assemblages and microscopic examinations of the Moroccan material. We conclude that
Nassarius
shells were consistently used for personal ornamentation in this region at the end of the last interglacial. Absence of ornaments at Middle Paleolithic sites postdating Marine Isotope Stage 5 raises the question of the possible role of climatic changes in the disappearance of this hallmark of symbolic behavior before its reinvention 40 ka ago. Our results suggest that further inquiry is necessary into the mechanisms of cultural transmission within early
Homo sapiens
populations.
The GTPase Rab3b/3c-positive recycling vesicles are involved in cross-presentation in dendritic cells
Authors: Zou Liyun , Zhou Jingran , Zhang Jinyu , Li Jingyi , Liu Na , Chai Linlin , Li Na , Liu Ting , Li Liqi , Xie Zhunyi , Liu Hongli , Wan Ying , Wu Yuzhang
Published: August 2009

Antigen cross-presentation in dendritic cells is a complex intracellular membrane transport process, but the underlying molecular mechanisms remain to be thoroughly investigated. In this study, we examined the effect of siRNA-mediated knockdown of 57 Rab GTPases, the key regulators of membrane trafficking, on antigen cross-presentation. Twelve Rab GTPases were identified to be associated with antigen cross-presentation, and Rab3b/3c was indicated to be colocalized with MHC class I molecules at perinuclear tubular structure. Tracing with fluorescence protein-tagged β2-microglobulin demonstrated that the MHC class I molecules were internalized from the plasma membrane to Rab3b/3c-positive compartments, which were also colocalized with the internalized transferrin. Moreover, depletion of Rab3b/3c strongly reduced the fast phase recycling rate of transferrin receptors. Furthermore, the Rab3b/3c-positive compartments were colocalized with a fraction of Rab27a at a juxtaposition of phagosomes. Together, these data demonstrate that Rab3b/3c-positive recycling vesicles are involved in and may constitute one of the recycling compartments in exogenous antigen cross-presentation.
Statistical mechanics and hydrodynamics of bacterial suspensions
Authors: Baskaran Aparna , Marchetti M. Cristina
Published: August 2009

Unicellular living organisms, such as bacteria and algae, propel themselves through a medium via cyclic strokes involving the motion of cilia and flagella. Dense populations of such “active particles” or “swimmers” exhibit a rich collective behavior at large scales. Starting with a minimal physical model of a stroke-averaged swimmer in a fluid, we derive a continuum description of a suspension of active organisms that incorporates fluid-mediated, long-range hydrodynamic interactions among the swimmers. Our work demonstrates that hydrodynamic interactions provide a simple, generic origin for several nonequilibrium phenomena predicted or observed in the literature. The continuum model derived here does not depend on the microscopic physical model of the individual swimmer. The details of the large-scale physics do, however, differ for “shakers” (particles that are active but not self-propelled, such as melanocytes) and “movers” (self-propelled particles), “pushers” (most bacteria) and “pullers” (algae like Chlamydomonas). Our work provides a classification of the large-scale behavior of all these systems.
Nonlinear temperature effects indicate severe damages to U.S. crop yields under climate change
Authors: Schlenker Wolfram , Roberts Michael J.
Published: August 2009

The United States produces 41% of the world's corn and 38% of the world's soybeans. These crops comprise two of the four largest sources of caloric energy produced and are thus critical for world food supply. We pair a panel of county-level yields for these two crops, plus cotton (a warmer-weather crop), with a new fine-scale weather dataset that incorporates the whole distribution of temperatures within each day and across all days in the growing season. We find that yields increase with temperature up to 29° C for corn, 30° C for soybeans, and 32° C for cotton but that temperatures above these thresholds are very harmful. The slope of the decline above the optimum is significantly steeper than the incline below it. The same nonlinear and asymmetric relationship is found when we isolate either time-series or cross-sectional variations in temperatures and yields. This suggests limited historical adaptation of seed varieties or management practices to warmer temperatures because the cross-section includes farmers' adaptations to warmer climates and the time-series does not. Holding current growing regions fixed, area-weighted average yields are predicted to decrease by 30–46% before the end of the century under the slowest (B1) warming scenario and decrease by 63–82% under the most rapid warming scenario (A1FI) under the Hadley III model.
A force field for virtual atom molecular mechanics of proteins
Authors: Korkut Anil , Hendrickson Wayne A.
Published: August 2009

Activities of many biological macromolecules involve large conformational transitions for which crystallography can specify atomic details of alternative end states, but the course of transitions is often beyond the reach of computations based on full-atomic potential functions. We have developed a coarse-grained force field for molecular mechanics calculations based on the virtual interactions of Cα atoms in protein molecules. This force field is parameterized based on the statistical distribution of the energy terms extracted from crystallographic data, and it is formulated to capture features dependent on secondary structure and on residue-specific contact information. The resulting force field is applied to energy minimization and normal mode analysis of several proteins. We find robust convergence in minimizations to low energies and energy gradients with low degrees of structural distortion, and atomic fluctuations calculated from the normal mode analyses correlate well with the experimental B-factors obtained from high-resolution crystal structures. These findings suggest that the virtual atom force field is a suitable tool for various molecular mechanics applications on large macromolecular systems undergoing large conformational changes.
Caterpillars evolved from onychophorans by hybridogenesis
Authors: Williamson Donald I.
Published: August 2009

I reject the Darwinian assumption that larvae and their adults evolved from a single common ancestor. Rather I posit that, in animals that metamorphose, the basic types of larvae originated as adults of different lineages, i.e., larvae were transferred when, through hybridization, their genomes were acquired by distantly related animals. “Caterpillars,” the name for eruciforms with thoracic and abdominal legs, are larvae of lepidopterans, hymenopterans, and mecopterans (scorpionflies). Grubs and maggots, including the larvae of beetles, bees, and flies, evolved from caterpillars by loss of legs. Caterpillar larval organs are dismantled and reconstructed in the pupal phase. Such indirect developmental patterns (metamorphoses) did not originate solely by accumulation of random mutations followed by natural selection; rather they are fully consistent with my concept of evolution by hybridogenesis. Members of the phylum Onychophora (velvet worms) are proposed as the evolutionary source of caterpillars and their grub or maggot descendants. I present a molecular biological research proposal to test my thesis. By my hypothesis 2 recognizable sets of genes are detectable in the genomes of all insects with caterpillar grub- or maggot-like larvae: (i) onychophoran genes that code for proteins determining larval morphology/physiology and (ii) sequentially expressed insect genes that code for adult proteins. The genomes of insects and other animals that, by contrast, entirely lack larvae comprise recognizable sets of genes from single animal common ancestors.
Thickness-dependent bending modulus of hexagonal boron nitride nanosheets
Authors: Li Chun , Bando Yoshio , Zhi Chunyi , Huang Yang , Golberg Dmitri
Published: August 2009

Bending modulus of exfoliation-made single-crystalline hexagonal boron nitride nanosheets (BNNSs) with thicknesses of 25–300 nm and sizes of 1.2–3.0  µm were measured using three-point bending tests in an atomic force microscope. BNNSs suspended on an SiO2trench were clamped by a metal film via microfabrication based on electron beam lithography. Calculated by the plate theory of a doubly clamped plate under a concentrated load, the bending modulus of BNNSs was found to increase with the decrease of sheet thickness and approach the theoreticalC33value of a hexagonal BN single crystal in thinner sheets (thickness<50 nm). The thickness-dependent bending modulus was suggested to be due to the layer distribution of stacking faults which were also thought to be responsible for the layer-by-layer BNNS exfoliation.
ANCHOR: web server for predicting protein binding regions in disordered proteins
Authors: Dosztányi Zsuzsanna , Mészáros Bálint , Simon István
Published: August 2009

Summary: ANCHOR is a web-based implementation of an original method that takes a single amino acid sequence as an input and predicts protein binding regions that are disordered in isolation but can undergo disorder-to-order transition upon binding. The server incorporates the result of a general disorder prediction method, IUPred and can carry out simple motif searches as well.

Availability: The web server is available at http://anchor.enzim.hu. The program package is freely available for academic users.

Contact:  zsuzsa@enzim.hu
Effects of the 2002 Sniper Attacks on the Homeless Population in Washington, DC
Authors: Fullerton Carol S. , Gifford Robert K. , Flynn Brian W. , Peterson Karen M. , Ahearn Frederick L. , Donaldson Linda Plitt , Ursano Robert J.
Published: August 2009

Objective:Despite the prevalence of homelessness, this population has rarely been included in disaster and terrorism planning. To better understand the mental health needs of the homeless during a terrorist event and to highlight the need to address methodological limitations in research in this area, we examined responses to the October 2002 Washington, DC, sniper attacks.

Methods:We interviewed 151 homeless individuals 1 year after the Washington, DC, sniper attacks.

Results:The majority (92.7%) was aware of the sniper events; 84.1% stayed informed through the media and 72.7% had someone to turn to for emotional support. Almost half (44%) reported identification with victims and 41% increased substance use during the attacks. More than half (61.7%) felt extremely frightened or terrified and 57.6% reported high perceived threat. Females, nonwhites, and participants with less than a high school education experienced greater threat. Women, nonwhites, and younger (<43 years old) participants were more likely to have decreased more activities and 32.7% increased confidence in local law enforcement; however, 32.7% became less confident.

Conclusions:During a terrorist attack the homeless population may be difficult to reach or reluctant to comply with public health programs. Addressing barriers to health care in vulnerable groups is critical to effective public health disaster response. (Disaster Med Public Health Preparedness. 2009;3:163–167)
Comparative genomic analyses of the human fungal pathogens Coccidioides and their relatives
Authors: Sharpton Thomas J. , Stajich Jason E. , Rounsley Steven D. , Gardner Malcolm J. , Wortman Jennifer R. , Jordar Vinita S. , Maiti Rama , Kodira Chinnappa D. , Neafsey Daniel E. , Zeng Qiandong , Hung Chiung-Yu , McMahan Cody , Muszewska Anna , Grynberg Marcin , Mandel M. Alejandra , Kellner Ellen M. , Barker Bridget M. , Galgiani John N. , Orbach Marc J. , Kirkland Theo N. , Cole Garry T. , Henn Matthew R. , Birren Bruce W. , Taylor John W.
Published: August 2009

While most Ascomycetes tend to associate principally with plants, the dimorphic fungi Coccidioides immitis and Coccidioides posadasii are primary pathogens of immunocompetent mammals, including humans. Infection results from environmental exposure to Coccidiodies, which is believed to grow as a soil saprophyte in arid deserts. To investigate hypotheses about the life history and evolution of Coccidioides, the genomes of several Onygenales, including C. immitis and C. posadasii; a close, nonpathogenic relative, Uncinocarpus reesii; and a more diverged pathogenic fungus, Histoplasma capsulatum, were sequenced and compared with those of 13 more distantly related Ascomycetes. This analysis identified increases and decreases in gene family size associated with a host/substrate shift from plants to animals in the Onygenales. In addition, comparison among Onygenales genomes revealed evolutionary changes in Coccidioides that may underlie its infectious phenotype, the identification of which may facilitate improved treatment and prevention of coccidioidomycosis. Overall, the results suggest that Coccidioides species are not soil saprophytes, but that they have evolved to remain associated with their dead animal hosts in soil, and that Coccidioides metabolism genes, membrane-related proteins, and putatively antigenic compounds have evolved in response to interaction with an animal host.
ETHYLENE INSENSITIVE3 and ETHYLENE INSENSITIVE3-LIKE1 Repress SALICYLIC ACID INDUCTION DEFICIENT2 Expression to Negatively Regulate Plant Innate Immunity in Arabidopsis
Authors: Chen Huamin , Xue Li , Chintamanani Satya , Germain Hugo , Lin Huiqiong , Cui Haitao , Cai Run , Zuo Jianru , Tang Xiaoyan , Li Xin , Guo Hongwei , Zhou Jian-Min
Published: August 2009

Pathogen/microbe-associated molecular patterns (PAMPs/MAMPs) trigger plant immunity that forms the first line inducible defenses in plants. The regulatory mechanism of MAMP-triggered immunity, however, is poorly understood. Here, we show that Arabidopsis thaliana transcription factors ETHYLENE INSENSITIVE3 (EIN3) and ETHYLENE INSENSITIVE3-LIKE1 (EIL1), previously known to mediate ethylene signaling, also negatively regulate PAMP-triggered immunity. Plants lacking EIN3 and EIL1 display enhanced PAMP defenses and heightened resistance to Pseudomonas syringae bacteria. Conversely, plants overaccumulating EIN3 are compromised in PAMP defenses and exhibit enhanced disease susceptibility to Pseudomonas syringae. Microarray analysis revealed that EIN3 and EIL1 negatively control PAMP response genes. Further analyses indicated that SALICYLIC ACID INDUCTION DEFICIENT2 (SID2), which encodes isochorismate synthase required for pathogen-induced biosynthesis of salicylic acid (SA), is a key target of EIN3 and EIL1. Consistent with this, the ein3-1 eil1-1 double mutant constitutively accumulates SA in the absence of pathogen attack, and a mutation in SID2 restores normal susceptibility in the ein3 eil1 double mutant. EIN3 can specifically bind SID2 promoter sequence in vitro and in vivo. Taken together, our data provide evidence that EIN3/EIL1 directly target SID2 to downregulate PAMP defenses.
The Arabidopsis CORONATINE INSENSITIVE1 Protein Is a Jasmonate Receptor
Authors: Yan Jianbin , Zhang Chi , Gu Min , Bai Zhiyan , Zhang Weiguo , Qi Tiancong , Cheng Zhiwei , Peng Wen , Luo Haibin , Nan Fajun , Wang Zhao , Xie Daoxin
Published: August 2009

Jasmonates play a number of diverse roles in plant defense and development. CORONATINE INSENSITIVE1 (COI1), an F-box protein essential for all the jasmonate responses, interacts with multiple proteins to form the SCFCOI1 E3 ubiquitin ligase complex and recruits jasmonate ZIM-domain (JAZ) proteins for degradation by the 26S proteasome. To determine which protein directly binds to jasmonoyl-isoleucine (JA-Ile)/coronatine (COR) and serves as a receptor for jasmonate, we built a high-quality structural model of COI1 and performed molecular modeling of COI1–jasmonate interactions. Our results imply that COI1 has the structural traits for binding JA-Ile or COR. The direct binding of these molecules with COI1 was further examined using a combination of molecular and biochemical approaches. First, we used the immobilized jasmonate approach to show that the COI1 protein in crude leaf extracts can bind to the jasmonate moiety of JA-Ile. Second, we employed surface plasmon resonance technology with purified COI1 and JAZ1 protein to reveal the interaction among COI1, JA-Ile, and JAZ1. Finally, we used the photoaffinity labeling technology to show the direct binding of COR with purified insect-expressed COI1. Taken together, these results demonstrate that COI1 directly binds to JA-Ile and COR and serves as a receptor for jasmonate.
Differential Recruitment ofWOXTranscription Factors for Lateral Development and Organ Fusion in Petunia andArabidopsis
Authors: Vandenbussche Michiel , Horstman Anneke , Zethof Jan , Koes Ronald , Rijpkema Anneke S. , Gerats Tom
Published: August 2009

Petal fusion in petunia (Petunia × hybrida) results from lateral expansion of the five initially separate petal primordia, forming a ring-like primordium that determines further development. Here, we show that MAEWEST (MAW) and CHORIPETALA SUZANNE (CHSU) are required for petal and carpel fusion, as well as for lateral outgrowth of the leaf blade. Morphological and molecular analysis of maw and maw chsu double mutants suggest that polarity defects along the adaxial/abaxial axis contribute to the observed reduced lateral outgrowth of organ primordia. We show that MAW encodes a member of the WOX (WUSCHEL-related homeobox) transcription factor family and that a partly similar function is redundantly encoded by WOX1 and PRESSED FLOWER (PRS) in Arabidopsis thaliana, indicating a conserved role for MAW/WOX1/PRS genes in regulating lateral organ development. Comparison of petunia maw and Arabidopsis  wox1 prs phenotypes suggests differential recruitment of WOX gene function depending on organ type and species. Our comparative data together with previous reports on WOX gene function in different species identify the WOX gene family as highly dynamic and, therefore, an attractive subject for future evo-devo studies.
The Trihelix Transcription Factor GTL1 Regulates Ploidy-Dependent Cell Growth in theArabidopsisTrichome
Authors: Breuer Christian , Kawamura Ayako , Ichikawa Takanari , Tominaga-Wada Rumi , Wada Takuji , Kondou Youichi , Muto Shu , Matsui Minami , Sugimoto Keiko
Published: August 2009

Leaf trichomes in Arabidopsis thaliana develop through several distinct cellular processes, such as patterning, differentiation, and growth. Although recent studies have identified several key transcription factors as regulating early patterning and differentiation steps, it is still largely unknown how these regulatory proteins mediate subsequent trichome development, which is accompanied by rapid cell growth and branching. Here, we report a novel trichome mutation in Arabidopsis, which in contrast with previously identified mutants, increases trichome cell size without altering its overall patterning or branching. We show that the corresponding gene encodes a GT-2-LIKE1 (GTL1) protein, a member of the trihelix transcription factor family. GTL1 is present within the nucleus during the postbranching stages of trichome development, and its loss of function leads to an increase in the nuclear DNA content only in trichomes that have completed branching. Our data further demonstrate that the gtl1 mutation modifies the expression of several cell cycle genes and partially rescues the ploidy defects in the cyclin-dependent kinase inhibitor mutant siamese. Taken together, this study provides the genetic evidence for the requirement of transcriptional regulation in the repression of ploidy-dependent plant cell growth as well as for an involvement of GTL trihelix proteins in this regulation.
Childhood growth hormone deficiency, bone density, structures and fractures: scrutinizing the evidence
Authors: Högler Wolfgang , Shaw Nick
Published: August 2009

Childhood‐onset growth hormone deficiency (GHD) is frequently perceived to cause low bone density, fractures and osteoporosis. This article critically reviews the evidence behind these perceptions. Inherent limitations of current bone imaging techniques have caused many artefacts and misconceptions about bone density and structure. Using appropriate size‐corrections, bone density is normal in children and adults with isolated GHD. Cortical density, trabecular density and trabecular volume are normal when measured by peripheral quantitative computerized tomography and histomorphometry. The only verifiable deficit affects cortical thickness (periosteal expansion), both in human and animal studies. However, short limb bones cannot be expected to have an average‐sized shaft, as bone elongation and widening could be proportionally impaired in GHD. In addition, GH and IGF‐1 have indisputable anabolic actions not only on bone, but also on muscle tissue. In fact, compared with all other bone‐related variables, muscle size is the lowest at diagnosis of GHD. During GH therapy, muscle enlargement precedes and exceeds any gain in bone mass. The mechanostat theory suggests that the GHD‐induced deficit in muscle force secondarily causes low cortical thickness. There is no evidence that isolated childhood‐onset GHD, or severe GH resistance, causes an increased fracture risk in children or adults. Only adults with organic hypopituitarism appear to have a slightly greater risk of fractures. Using current transition guidelines, short children and adults with GHD are at risk of being misdiagnosed with low bone mass and may consequently receive inappropriate treatment. As neither reports of increased fracture risk nor low bone density can stand up against scrutiny, these misconceptions should no longer influence clinical practice. In this respect, GHD should not be listed as a cause of osteoporosis in children and there is a need to review current transition guidelines.
Aberrant G‐protein coupled receptor expression in relation to adrenocortical overfunction
Authors: Lacroix André , Bourdeau Isabelle , Lampron Antoine , Mazzuco Tânia L. , Tremblay Johanne , Hamet Pavel
Published: August 2009

The aberrant adrenal expression and function of one or several G‐protein coupled receptors can lead to cell proliferation and abnormal regulation of steroidogenesis in unilateral adenomas, carcinomas or in ACTH‐independent macronodular adrenal hyperplasia (AIMAH). Excess cortisol secretion leading to either sub‐clinical or overt Cushing’s syndrome is the most prevalent phenotype reported to date. In a few patients, aberrant regulation of androgen excess has been reported. More recently, initial studies suggest that similar mechanisms are involved in the renin‐independent regulation of aldosterone secretion in primary aldosteronism. In recent years, cases of familial AIMAH have been identified, and specific aberrant hormone receptors are functional in the adrenal of affected members. The identification of aberrant receptors can offer specific pharmacological approach to prevent disease progression and control abnormal steroidogenesis; alternatively, unilateral or bilateral adrenalectomy remains the treatment of choice.
Chloroplast‐generated reactive oxygen species play a major role in localized cell death during the non‐host interaction between tobacco and Xanthomonas campestris pv. vesicatoria
Authors: Zurbriggen Matias D. , Carrillo Néstor , Tognetti Vanesa B. , Melzer Michael , Peisker Martin , Hause Bettina , Hajirezaei Mohammad‐Reza
Published: August 2009

Attempted infection of plants by pathogens elicits a complex defensive response. In many non‐host and incompatible host interactions it includes the induction of defence‐associated genes and a form of localized cell death (LCD), purportedly designed to restrict pathogen advance, collectively known as the hypersensitive response (HR). It is preceded by an oxidative burst, generating reactive oxygen species (ROS) that are proposed to cue subsequent deployment of the HR, although neither the origin nor the precise role played by ROS in the execution of this response are completely understood. We used tobacco plants expressing cyanobacterial flavodoxin to address these questions. Flavodoxin is an electron shuttle present in prokaryotes and algae that, when expressed in chloroplasts, specifically prevents ROS formation in plastids during abiotic stress episodes. Infiltration of tobacco wild‐type leaves with high titres of Xanthomonas campestris pv. vesicatoria (Xcv), a non‐host pathogen, resulted in ROS accumulation in chloroplasts, followed by the appearance of localized lesions typical of the HR. In contrast, chloroplast ROS build‐up and LCD were significantly reduced in Xcv‐inoculated plants expressing plastid‐targeted flavodoxin. Metabolic routes normally inhibited by pathogens were protected in the transformants, whereas other aspects of the HR, including the induction of defence‐associated genes and synthesis of salicylic and jasmonic acid, proceeded as in inoculated wild‐type plants. Therefore, ROS generated in chloroplasts during this non‐host interaction are essential for the progress of LCD, but do not contribute to the induction of pathogenesis‐related genes or other signalling components of the response.
Role of WRINKLED1 in the transcriptional regulation of glycolytic and fatty acid biosynthetic genes in Arabidopsis
Authors: Baud Sébastien , Wuillème Sylvie , To Alexandra , Rochat Christine , Lepiniec Loïc
Published: August 2009

The WRINKLED1 (WRI1) protein is an important regulator of oil accumulation in maturing Arabidopsis seeds. WRI1 is a member of a plant‐specific family of transcription factors (AP2/EREBP) that share either one or two copies of a DNA‐binding domain called the AP2 domain. Here, it is shown that WRI1 acts as a transcriptional enhancer of genes involved in carbon metabolism in transgenic seeds overexpressing this transcription factor. PKp‐β1 and BCCP2, two genes encoding enzymes of the glycolysis and fatty acid biosynthetic pathway, respectively, have been chosen to investigate the regulatory action exerted by WRI1 over these pathways. Using the reporter gene uidA, it was possible to demonstrate in planta that WRI1 regulates the activity of both PKp‐β1 and BCCP2 promoters. Electrophoretic mobility‐shift assays and yeast one‐hybrid experiments showed that WRI1 was able to interact with the BCCP2 promoter. To further elucidate the regulatory mechanism controlling the transcription of these genes, functional dissections of PKp‐β1 and BCCP2 promoters were performed. Two enhancers, of 54 and 79 bp, respectively, have thus been isolated that are essential to direct the activity of these promoters in oil‐accumulating tissues of the embryo. A consensus site is present in these enhancers as well as in other putative target promoters of WRI1. Loss of this consensus sequence in the BCPP2 promoter decreases both the strength of the interaction between WRI1 and this promoter in yeast and the activity of the promoter in planta.
Phosphorus alleviates aluminum‐induced inhibition of growth and photosynthesis in Citrus grandis seedlings
Authors: Jiang Huan‐Xin , Tang Ning , Zheng Jin‐Gui , Li Yan , Chen Li‐Song
Published: August 2009

Limited data are available on the effects of phosphorus (P) and aluminum (Al) interactions on Citrus spp. growth and photosynthesis. Sour pummelo (Citrus grandis) seedlings were irrigated for 18 weeks with nutrient solution containing 50, 100, 250 and 500 μM KH2PO4× 0 and 1.2 mM AlCl3· 6H2O. Thereafter, P and Al in roots, stems and leaves, and leaf chlorophyll (Chl), CO2 assimilation, ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) and Chl a fluorescence (OJIP) transients were measured. Under Al stress, P increased root Al, but decreased stem and leaf Al. Shoot growth is more sensitive to Al than root growth, CO2 assimilation and OJIP transients. Al decreased CO2 assimilation, Rubisco activity and Chl content, whereas it increased or did not affect intercellular CO2 concentration. Al affected CO2 assimilation more than Rubisco and Chl under 250 and 500 μM P. Al decreased root, stem and leaf P, leaf maximum quantum yield of primary photochemistry (Fv/Fm) and total performance index (PItot,abs), but increased leaf minimum fluorescence (Fo), relative variable fluorescence at K‐ and I‐steps. P could alleviate Al‐induced increase or decrease for all these parameters. We conclude that P alleviated Al‐induced inhibition of growth and impairment of the whole photosynthetic electron transport chain from photosystem II (PSII) donor side up to the reduction of end acceptors of photosystem I (PSI), thus preventing photosynthesis inhibition through increasing Al immobilization in roots and P level in roots and shoots. Al‐induced impairment of the whole photosynthetic electron transport chain may be associated with growth inhibition.
Inflammation in ischaemic brain injury: Current advances and future perspectives
Authors: Xia Weiliang , Han Jin , Huang Gang , Ying Weihai
Published: August 2009

1. Numerous studies have indicated that inflammation plays a key role in ischaemic brain injury. Brain ischaemia–reperfusion‐induced inflammatory responses include increased microglial and astrocyte activity, increased production of cytokines, chemokines, adhesion molecules and metalloproteinases and the infiltration of monocytes and leucocytes into injured brain regions.

2. Although a significant proportion of the inflammatory response appears to exacerbate ischaemic brain injury, certain inflammatory responses are beneficial to ischaemic brains. It is necessary to further identify the detrimental and beneficial inflammatory responses so that therapeutic strategies can be designed for stroke patients to selectively inhibit detrimental responses while enhancing beneficial responses.

3. Increasing evidence also indicates significant changes in the peripheral immune system of stroke patients and animals that undergo cerebral ischaemia. It is worth elucidating the effects of these changes in ischaemic brain damage.

4. There are complex interactions in the ischaemic brain between microglia and other cell types, including neurons, astrocytes, endothelial cells and stem cells. It is of particular interest to determine the mechanisms underlying the roles of high‐mobility group box‐1, advanced glycation end‐products receptors (RAGE), S100B and NADPH oxidase in these interactions.

5. Because brain ischaemia‐induced inflammation is a relatively long‐lasting event with profound effects on brain injury, it is of considerable importance to further investigate the mechanisms underlying inflammation in ischaemic brains.
Renal vasodilation induced by hypernatraemia: Role of α‐adrenoceptors in the median preoptic nucleus
Authors: Pedrino Gustavo R , Monaco Luciana R , Cravo Sergio L
Published: August 2009

1. The renal vasodilation induced by infusion of hypertonic saline (HS) in anaesthetized rats has been shown to depend on the integrity of the median preoptic nucleus (MnPO), as well as noradrenergic afferents to this nucleus. In the present study, we sought to determine the role of α1 and α2‐adrenoceptors in the MnPO in cardiovascular responses induced by intravenous HS infusion (3 mol/L NaCl; 1.8 mL/kg, i.v., over 1 min).

2. Male Wistar rats (320–360 g) were anaesthetized with urethane (1.2 g/kg, i.v.) and instrumented for recording of mean arterial pressure (MAP), renal blood flow (RBF) and vascular conductance (RVC). In one experimental group, rats were injected with yohimbine, prazosin or saline (control) 20 min before HS infusion. In another experimental group, rats were injected with yohimbine or prazosin 20 min after HS infusion.

3. In control rats (n = 7), HS infusion 20 min after saline nanoinjection produced a transient hypertension. Ten minutes after HS infusion, RBF and RVC increased to 159 ± 14% and 145 ± 11% of baseline, respectively. Nanoinjection of the α1‐adrenoceptor antagonist prazosin (0.25 mmol/L; n = 6) into the MnPO 20 min before HS infusion increased the HS‐induced pressor response. However, HS‐induced increases in RBF and RVC were significantly reduced (130 ± 11% and 105 ± 6% of baseline, respectively, 10 min after HS). Nanoinjection of the α2‐adrenoceptor antagonist yohimbine (0.23 mmol/L; n = 5) into the MnPO 20 min before HS infusion increased the duration of the pressor response and reduced the increases in RBF and RVC induced by HS (117 ± 10% and 97 ± 11% of baseline, respectively, 10 min after HS).

4. We also observed that nanoinjections of the prazosin into the MnPO 60 min after HS infusion resulted in a gradual return of RBF and RVC to baseline values. However nanoinjection of yohimbine 60 min after HS failed to reduce renal vasodilatation induced by hypernatremia.

5. The results of the present study demonstrate that the integrity of adrenergic neurotransmission in the MnPO is essential for the renal vasodilation that follows acute increases in blood sodium concentration.