bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methionine and threonine synthesis are limited by homoserine availability and not the activity of homoserine kinase in Arabidopsis thaliana
Authors: Lee Minsang , Martin Melinda N. , Hudson Andre’ O. , Lee Jiyeon , Muhitch Michael J. , Leustek Thomas 
Published: February 2005

SummaryHomoserine kinase (HSK) produces O‐phospho‐l‐homoserine (HserP) used by cystathionine γ‐synthase (CGS) for Met synthesis and threonine synthase (TS) for Thr synthesis. The effects of overexpressing Arabidopsis thaliana HSK, CGS, and Escherichia coli TS (eTS), each controlled by the 35S promoter, were compared. The results indicate that in Arabidopsis Hser supply is the major factor limiting the synthesis of HserP, Met and Thr. HSK is not limiting and CGS or TS control the partitioning of HserP. HSK overexpression had no effect on the level of soluble HserP, Met or Thr, however, when treated with Hser these plants produced far more HserP than wild type. Met and Thr also accumulated markedly after Hser treatment but the increase was similar in HSK overexpressing and wild‐type plants. CGS overexpression was previously shown to increase Met content, but had no effect on Thr. After Hser treatment Met accumulation increased in CGS‐overexpressing plants compared with wild type, whereas HserP declined and Thr was unaffected. Arabidopsis responded differentially to eTS expression depending on the level of the enzyme. At the highest eTS level the Thr content was not increased, but the phenotype was negatively affected and the T1 plants died before reproducing. Comparatively low eTS did not affect phenotype or Thr/Met level, however after Hser treatment HserP and Met accumulation were reduced compared with wild type and Thr was increased slightly. At intermediate eTS activity seedling growth was retarded unless Met was supplied and CGS expression was induced, indicating that eTS limited HserP availability for Met synthesis.
Ethylene‐binding activity, gene expression levels, and receptor system output for ethylene receptor family members from Arabidopsis and tomato†
Authors: O'Malley Ronan C. , Rodriguez Fernando I. , Esch Jeffrey J. , Binder Brad M. , O'Donnell Philip , Klee Harry J. , Bleecker Anthony B. 
Published: February 2005

SummaryEthylene signaling in plants is mediated by a family of ethylene receptors related to bacterial two‐component regulators. Expression in yeast of ethylene‐binding domains from the five receptor isoforms from Arabidopsis thaliana and five‐receptor isoforms from tomato confirmed that all members of the family are capable of high‐affinity ethylene‐binding activity. All receptor isoforms displayed a similar level of ethylene binding on a per unit protein basis, while members of both subfamily I and subfamily II from Arabidopsis showed similar slow‐release kinetics for ethylene. Quantification of receptor‐isoform mRNA levels in receptor‐deficient Arabidopsis lines indicated a direct correlation between total message level and total ethylene‐binding activity in planta. Increased expression of remaining receptor isoforms in receptor‐deficient lines tended to compensate for missing receptors at the level of mRNA expression and ethylene‐binding activity, but not at the level of receptor signaling, consistent with specialized roles for family members in receptor signal output.
Genome‐wide profiling of stored mRNA inArabidopsis thalianaseed germination: epigenetic and genetic regulation of transcription in seed
Authors: Nakabayashi Kazumi , Okamoto Masanori , Koshiba Tomokazu , Kamiya Yuji , Nambara Eiji 
Published: February 2005

SummaryTo reveal the transcriptomes of Arabidopsis seed, comprehensive expression analysis was performed using ATH1 GeneChips (Affymetrix, Santa Clara, CA, USA). In the dry seed, more than 12 000 stored mRNA species were detected, including all ontological categories. Statistical analysis revealed that promoters of highly expressed genes in wild‐type dry seeds overrepresented abscisic acid‐responsive elements (ABREs) containing the core motif ACGT. Although the coupling element and seed‐specific enhancer RY motif alone were not prominently overrepresented in genes with high expression, the presence of these elements in combination with ABRE was associated with particularly high gene expression. The transcriptome of the imbibed seeds differed from that of the dry seed even at 6 h after seed imbibition. After imbibition many upregulated and downregulated genes were co‐regulated in clusters of three to five genes. Genes for which expression was affected by theabi5mutation tended to be located in clusters, suggesting that transactivation by ABI5 is not restricted to a single gene, but affects other proximal genes. Furthermore, cytosine methylation was observed not only in large silent retrotransposon clusters in centromeric regions, but also in non‐centromeric silent gene clusters in the seed. These results suggest that such regions might be transcriptionally silenced by methylation or heterochromatin structures. Our analyses reveal that transcriptomes of Arabidopsis seed are characterized by multiple regulatory mechanisms: epigenetic chromatin structures, chromosomal locations (e.g. co‐regulated gene clusters) andcis‐acting elements.
A Phytoalexin‐Like Flavonol Involved in the Carnation (Dianthus caryophyllus)‐Fusarium oxysporum f. sp. dianthi Pathosystem
Authors: Curir P. , Dolci M. , Galeotti F. 
Published: February 2005

AbstractThe fungitoxic flavonol triglycoside, kaempferide 3‐O‐[2G‐β‐d‐glucopyranosyl]‐β‐rutinoside, is a constituent of the carnation cultivar ‘Novada’, known as one of the most resistant cultivar to Fusarium oxysporum f. sp. dianthi, causative agent of Fusarium wilt. Due to its constitutive presence within the carnation tissues, this antifungal flavonol should be considered as a phytoanticipin; its biosynthesis, however, is stimulated by the inoculation with F. oxysporum f. sp. dianthi, just as is the rule for a typical phytoalexin. The results seem to indicate that in carnation the concentration of some preformed antifungal flavonoids may be significantly increased by a fungal presence: owing to their fungitoxic properties, these molecules could cooperate, together with the unconstitutive and postinfectional anthranilic acid‐derivative phytoalexins, to the plant defensive response against Fusarium attacks.
Genetic Structure of Pyricularia grisea (Cooke) Sacc. Isolates from Italian Paddy Fields
Authors: Piotti E. , Rigano M. M. , Rodino D. , Rodolfi M. , Castiglione S. , Picco A. M. , Sala F. 
Published: February 2005

AbstractRice blast disease, caused by the fungus Pyricularia grisea (Cooke) Sacc., is responsible for considerable damages in rice crops in Italy and in other parts of the world. This study was conducted in order to investigate the genetic structure of a P. grisea population in the Po area, the largest rice area in Italy. Rice leaves showing blast symptoms were collected in three successive years (1998–2000) and 43 P. grisea monoconidial culture samples were isolated from infected rice leaves. Fungal DNAs were obtained from mycelia. Moreover, six additional P. grisea DNA samples representative for the five characterized European lineages were also investigated. All 49 DNAs were fingerprinted using the Pot2‐based repetitive polymerase chain reaction specific for the blast pathogen. Unweighted pair‐group method with arithmetic averages cluster analysis shows the presence of three main Italian lineages. Within lineages, similarity was higher than 80%. Samples representative of the three of five known European lineages grouped within these three Italian lineages confirming the presence of three European lineages in Italy. Furthermore, cluster analysis shows the presence of two new haplotypes never found before in the Italian lineage.
Characterization of Alder Phytophthora Isolates from Wallonia and Development of SCAR Primers for their Specific Detection
Authors: De Merlier D. , Chandelier A. , Debruxelles N. , Noldus M. , Laurent F. , Dufays E. , Claessens H. , Cavelier M. 
Published: February 2005

AbstractIsolates of alder Phytophthora were collected in the southern part of Belgium on riverbanks planted with Alnus glutinosa and A. incana. They were compared with strains isolated in other European countries in terms of maximum temperature for growth, oogonia shape, pathogenicity on Alnus seedlings and genetic traits. Using both molecular techniques [random amplified polymorphic DNA (RAPD) and random amplified microsatellite (RAMS)], two groups of isolates were identified, the first group being further divided into two subgroups, Ia and Ib, using RAPD. Most of the Walloon alder Phytophthora isolates as well as the standard type from UK (formally designated P. alni subsp. alni) fell into group Ia. One isolate was classified in group Ib with the German and Dutch variants (P. alni subsp. multiformis), while three isolates were placed with the Swedish variant (P. alni subsp. uniformis) in group II. In terms of morphological properties, isolates from groups Ia and Ib developed colonies with a felt‐like appearance and usually produced numerous oogonia, varying from wavy to warty after 1 week (group Ia) or 2–3 weeks (Ib) in darkness. In contrast, colonies from group II isolates were generally irregular, and smooth oogonia were produced in low quantities after approximately 1 month in culture. A polymerase chain reaction (PCR) using sequence‐characterized amplification region (SCAR) primers derived from a polymorphic amplification product generated with a RAPD primer was developed for the specific detection of alder Phytophthora. The specificity and sensitivity of this test are discussed here.
Age and perception of dental appearance and tooth colour
Authors: Alkhatib Mhd N. , Holt Ruth , Bedi Raman 
Published: February 2005

Objectives:  To determine the prevalence of satisfaction with dental appearance and own tooth colour in the UK and investigate the impact of ageing on these perceptions.Methods:  Data about ageing and satisfaction with dental appearance and tooth colour was gathered by means of a questionnaire completed at face‐to‐face interview. The questionnaire was first tested and then used by the Office of National Statistics (ONS) in a stratified random sample of adults drawn from the UK. A total of 3384 adults were interviewed.Results:  Three quarters of the population were satisfied with their own dental appearance and two‐thirds were satisfied with their tooth colour. Subjects over the age of 55 were significantly more likely to be satisfied with their dental appearance and tooth colour (p < 0.05) compared with younger age groups.Conclusions:  Ageing is not necessarily associated with negative self‐perception of dental appearance or tooth colour. Greater dissatisfaction with dental appearance or colour in younger ages may suggest that perceived appearance is linked to cognitive factors other than social or cultural ones.
Reflecting upon Feelings: An fMRI Study of Neural Systems Supporting the Attribution of Emotion to Self and Other
Authors: Ochsner Kevin N. , Knierim Kyle , Ludlow David H. , Hanelin Josh , Ramachandran Tara , Glover Gary , Mackey Sean C. 
Published: February 2005

AbstractUnderstanding one's own and other individual's emotional states is essential for maintaining emotional equilibrium and strong social bonds. Although the neural substrates supporting reflection upon one's own feelings have been investigated, no studies have directly examined attributions about the internal emotional states of others to determine whether common or distinct neural systems support these abilities. The present study sought to directly compare brain regions involved in judging one's own, as compared to another individual's, emotional state. Thirteen participants viewed mixed valence blocks of photos drawn from the International Affective Picture System while whole-brain fMRI data were collected. Preblock cues instructed participants to evaluate either their emotional response to each photo, the emotional state of the central figure in each photo, or (in a baseline condition) whether the photo was taken indoors or outdoors. Contrasts indicated (1) that both self and other judgments activated the medial prefrontal cortex (MPFC), the superior temporal gyrus, and the posterior cingulate/precuneus, (2) that self judgments selectively activated subregions of the MPFC and the left temporal cortex, whereas (3) other judgments selectively activated the left lateral prefrontal cortex (including Broca's area) and the medial occipital cortex. These results suggest (1) that self and other evaluation of emotion rely on a network of common mechanisms centered on the MPFC, which has been hypothesized to support mental state attributions in general, and (2) that medial and lateral PFC regions selectively recruited by self or other judgments may be involved in attention to, and elaboration of, internally as opposed to externally generated information.
Contextual Modulation of Amygdala Responsivity to Surprised Faces
Authors: Kim Hackjin , Somerville Leah H. , Johnstone Tom , Polis Sara , Alexander Andrew L. , Shin Lisa M. , Whalen Paul J. 
Published: February 2005

AbstractWe recently demonstrated a functional relationship between fMRI responses within the amygdala and the medial prefrontal cortex based upon whether subjects interpreted surprised facial expressions positively or negatively. In the present fMRI study, we sought to assess amygdala–medial prefrontal cortex responsivity when the interpretations of surprised faces were determined by contextual experimental stimuli, rather than subjective judgment. Subjects passively viewed individual presentations of surprised faces preceded by either a negatively or positively valenced contextual sentence (e.g., She just found $500 vs. She just lost $500). Negative and positive sentences were carefully matched in terms of length, situations described, and arousal level. Negatively cued surprised faces produced greater ventral amygdala activation compared to positively cued surprised faces. Responses to negative versus positive sentences were greater within the ventrolateral prefrontal cortex, whereas responses to positive versus negative sentences were greater within the ventromedial prefrontal cortex. The present study demonstrates that amygdala response to surprised facial expressions can be modulated by negatively versus positively valenced verbal contextual information. Connectivity analyses identified candidate cortical–subcortical systems subserving this modulation.
Grasping the Intentions of Others: The Perceived Intentionality of an Action Influences Activity in the Superior Temporal Sulcus during Social Perception
Authors: Pelphrey Kevin A. , Morris James P. , McCarthy Gregory 
Published: February 2005

Abstract
An explication of the neural substrates for social perception is an important component in the emerging field of social cognitive neuroscience and is relevant to the field of cognitive neuroscience as a whole. Prior studies from our laboratory have demonstrated that passive viewing of biological motion (Pelphrey, Mitchell, et al., 2003; Puce et al., 1998) activates the posterior superior temporal sulcus (STS) region. Furthermore, recent evidence has shown that the perceived context of observed gaze shifts (Pelphrey, Singerman, et al., 2003; Pelphrey et al., 2004) modulates STS activity. Here, using event-related functional magnetic resonance imaging at 4 T, we investigated brain activity in response to passive viewing of goal- and non-goal- directed reaching-to-grasp movements. Participants viewed an animated character making reaching-to-grasp movements either toward (correct) or away (incorrect) from a blinking dial. Both conditions evoked significant posterior STS activity that was strongly right lateralized. By examining the time course of the blood oxygenation level-dependent response from areas of activation, we observed a functional dissociation. Incorrect trials evoked significantly greater activity in the STS than did correct trials, while an area posterior and inferior to the STS (likely corresponding to the MT/V5 complex) responded equally to correct and incorrect movements. Parietal cortical regions, including the superior parietal lobule and the anterior intraparietal sulcus, also responded equally to correct and incorrect movements, but showed evidence for differential responding based on the hand and arm (left or right) of the animated character used to make the reaching-to-grasp movement. The results of this study further suggest that a region of the right posterior STS is involved in analyzing the intentions of other people's actions and that activity in this region is sensitive to the context of observed biological motions.
Implicit and Explicit Evaluation: fMRI Correlates of Valence, Emotional Intensity, and Control in the Processing of Attitudes
Authors: Cunningham William A. , Raye Carol L. , Johnson Marcia K. 
Published: February 2005

Abstract
Previous work suggests that explicit and implicit evaluations (good–bad) involve somewhat different neural circuits that process different dimensions such as valence, emotional intensity, and complexity. To better understand these differences, we used functional magnetic resonance imaging to identify brain regions that respond differentially to such dimensions depending on whether or not an explicit evaluation is required. Participants made either good–bad judgments (evaluative) or abstract–concrete judgments (not explicitly evaluative) about socially relevant concepts (e.g., “murder,” “happiness,” “abortion,” “welfare”). After scanning, participants rated the concepts for goodness, badness, emotional intensity, and how much they tried to control their evaluation of the concept. Amygdala activation correlated with emotional intensity and right insula activation correlated with valence in both tasks, indicating that these aspects of stimuli were processed by these areas regardless of intention. In contrast, for the explicitly evaluative good–bad task only, activity in the anterior cingulate, frontal pole, and lateral areas of the orbital frontal cortex correlated with ratings of control, which in turn were correlated with a measure of ambivalence. These results highlight that evaluations are the consequence of complex circuits that vary depending on task demands.
A Barotropic Envelope Rossby Soliton Model for Block–Eddy Interaction. Part II: Role of Westward-Traveling Planetary Waves
Authors: Luo Dehai 
Published: February 2005

AbstractThe role of westward-traveling planetary waves in the block onset and the deformation of eddies during the interaction between synoptic-scale eddies and an incipient block is first examined by constructing an incipient block that consists of a stationary dipole wave for zonal wavenumber 2 and a westward-traveling monopole wave with constant amplitude (C wave) for zonal wavenumber 1 or 2. It is shown that the C-wave can affect the onset and strength of blocking through influencing the preblock (diffluent) flow even though it does not affect the amplification of the dipole wave associated with the synoptic-scale eddies. Whether the storm tracks organized by the deformed eddies deflect northward depends upon the zonal wavenumber, amplitude, and phase of the C wave relative to the stationary dipole wave. A typical retrograde blocking anticyclone can arise through the interaction of an incipient block with synoptic-scale perturbations when the C-wave ridge with zonal wavenumber 1 shifts westward from the east of the dipole wave in an incipient block. In this process, a slight northward deflection of organized storm tracks is also observed, particularly under the condition of a large-amplitude C wave.In addition, the interaction between a diffluent flow, consisting of a coupled dipole and monopole waves, and upstream synoptic-scale eddies is investigated. It is found that the eddy forcing tends to not only periodically amplify the dipole soliton and to retard its eastward movement, but to make the monopole wave break up. The breaking of the traveling monopole wave will suppress the eddy-induced blocking ridge that exhibits a surf zone structure where the negative meridional gradient of planetary-scale potential vorticity exists and cause the planetary-scale blocking field to lose its closed circulation compared to that without coupling.
Assessment of Hydrometeor Collection Rates from Exact and Approximate Equations. Part I: A New Approximate Scheme
Authors: Gaudet Brian J. , Schmidt Jerome M. 
Published: February 2005

Abstract
The collection equation is analyzed for the case of two spherical hydrometeors with collection efficiency unity and exponential size distributions. When the fall velocities are significantly different a more general form of the conventional Wisner approximation can be formulated. The accuracy of the new formula exceeds that of the Wisner approximation for all cases considered, except for the collection of a faster species by a slower species if the amount of the faster species is relatively small compared with that of the slower species. The exact solution of the collection equation is then rederived and cast into the form of a power series involving the ratio of the two characteristic fall velocities. It is shown that the new formulation is a first-order correction to the continuous collection equation for hydrometeors with finite diameters and fall velocities. Based on the analysis, the implications for the behavior of both the exact collection equation and its representation in numerical models are discussed.
Spatial and Temporal Variations of Gravity Wave Parameters. Part I: Intrinsic Frequency, Wavelength, and Vertical Propagation Direction
Authors: Wang Ling , Geller Marvin A. , Alexander M. Joan 
Published: February 2005

Abstract
Five years (1998–2002) of U.S. high vertical resolution radiosonde data are analyzed to derive important gravity wave parameters, such as intrinsic frequencies, vertical and horizontal wavelengths, and vertical propagation directions in the lower stratosphere and troposphere.
Intrinsic frequencies ω̂ increase with increasing latitude, with larger values in the troposphere. In the lower stratosphere, ω̂ is higher in winter than in summer, especially at mid- and high latitudes. Intrinsic frequencies divided by the Coriolis parameter f are ∼4 in the troposphere, and ∼2.4–3 in the lower stratosphere. The lower-stratospheric ω̂/f generally decreases weakly with increasing latitude. The latitudinal distributions of the lower-stratospheric ω̂/f are explained largely by the propagation effects. The seasonal variations of ω̂ in the lower stratosphere are found to be related to the variations of the background wind speeds.
Dominant vertical wavelengths decrease with increasing latitude in the lower stratosphere, and maximize at midlatitudes (35°–40°N) in the troposphere. They are generally longer in winter than in summer. The variations of the dominant vertical wavelengths are found to be associated with the similar variations in gravity wave energies. Dominant horizontal wavelengths decrease with increasing latitude, with larger values in the lower stratosphere.
Approximately 50% of the tropospheric gravity waves show upward energy propagation, whereas there is about 75% upward energy propagation in the lower stratosphere. The lower-stratospheric fraction of upward energy propagation is generally smaller in winter than in summer, especially at mid- and high latitudes. The seasonal variation of upward fraction is likely an artifice due to the analysis method, although a small part of it may be interpreted by the variations in background wind speeds.
Results suggest that propagation effects are much more important than source variations for explaining the large-scale time-average properties of waves observed by radiosondes.