bluuebunny/crossref_metadata_2025 huggingface dataset:
ULTIMATE ATTAINMENT IN L2 PHONOLOGY
Authors: Moyer Alene
Published: July 2002

Within both first and
second language acquisition research, a critical or sensitive period for complete attainment has
largely been substantiated in phonological studies, although it is questionable whether age should
be examined in isolation from sociopsychological influences and the extent of exposure to the
second language. This study sets out to challenge the Critical Period Hypothesis (CPH) by
examining phonological performance among highly motivated subjects who use German daily as
graduate student instructors and who have been immersed in the language through in-country
residence, augmented by years of instruction in both language- and content-based courses. The
methodology developed seeks to expand the realm of factors that are potentially conflated with
age, such as instruction, motivation, suprasegmental training, and self-perception of productive
accuracy, and other factors that have not been addressed in previous studies on ultimate
attainment. Production tasks target sounds difficult for nonnative speakers (NNSs) according to
contrastive analysis, and task types range in complexity from isolated words to sentences,
paragraphs, and free speech. A mean rating was computed for each speaker, including native
speaker controls, according to native speaker judgments. When averaged across all tasks,
nonnative speaker performance did not overlap with native performance. However, several
variables correlated significantly with outcome, including suprasegmental training, which
indicated performance closer to native level.
THE ROLES OF MODIFIED INPUT AND OUTPUT IN THE
INCIDENTAL ACQUISITION OF WORD MEANINGS
Authors: Ellis Rod , He Xien
Published: July 2002

This article reports an experimental study of the differential effects of
premodified input, interactionally modified input, and modified output on the comprehension of
directions in a listen-and-do task and the acquisition of new words embedded in the directions.
The modified output group achieved higher comprehension and vocabulary acquisition scores
than either of the input groups. There was no difference between the premodified and
interactionally modified input groups. The advantage of the modified output group is explained
in terms of the qualitatively superior dialogic interaction that occurred in this condition rather
than in terms of actual language production.
TESTING THE OUTPUT HYPOTHESIS
Authors: Izumi Shinichi , Bigelow Martha , Fujiwara Miho , Fearnow Sarah
Published: July 2002

This study addresses one of the functions of output proposed by Swain (1993, 1995, 1998).
In particular, the activity of producing the target language may, under certain circumstances,
prompt L2 learners to recognize some of their linguistic problems and bring to their attention
something they need to discover about their L2. Two research questions were posed: (a) Does
output promote noticing of linguistic form? and (b) Does output result in improved performance
on the target form? In treatment phase 1, participants reconstructed a short passage after being
exposed to it, followed by a second exposure to the same input material and a second
reconstruction opportunity. In phase 2, participants wrote on given topics, followed by the
presentation of a model written by a native speaker. Participants wrote a second time on the same
topic. To test the noticing function of output, participants underlined parts of the sentences they
thought were “particularly necessary” for subsequent (re)production. The control
group was exposed to the same input materials but was not required to produce any output.
Although phase 1 tasks resulted in noticing and immediate incorporation of the target form, the
posttest performance failed to reveal their effects. In contrast, phase 2 tasks resulted in
improvement on posttest 2. The results are discussed in terms of the efficacy of output in
promoting noticing and learning and the conditions that may be required for output to be useful
for SLA.
The structure of /s/-sequences: evidence from a disordered system
Authors: A. BARLOW JESSICA
Published: July 2002

This study considers the much-debated markedness and structural
status of word-initial /s/-sequences in English by examining the
development of KR (male, age 3;6) who has a phonological disorder.
Three points in time are discussed: (1) when all initial consonant
sequences are reduced to singletons; (2) when only initial /s/-sequences
surface correctly; and (3) when all initial consonant sequences surface
correctly. While these production patterns are common across developing
systems, few accounts have addressed them in terms of structure or
markedness. Toward that end, it is argued that KR's /s/-sequences
surface as ADJUNCTS, rather than complex onsets. This is explained
within optimality theory, whereby high-ranking markedness constraints
prevent complex onsets but not adjuncts. The account offers an
explanation for consonant sequence asymmetries within and across
grammars, allowing for differing representations for /s/-sequences
across speakers and for variation exhibited in children's productions. A
typology of possible grammars is therefore offered, and clinical implications are considered.
Broadening the units of analysis in communication: speech and nonverbal behaviours in pragmatic comprehension
Authors: D. KELLY SPENCER
Published: July 2002

Recently, much research has explored the role that nonverbal pointing
behaviours play in children's early acquisition of language, for example
during word learning. However, few researchers have considered the
possibility that these behaviours may continue to play a role in language
comprehension as children develop more sophisticated language skills.
The present study investigates the role that eye gaze and pointing
gestures play in three- to five-year-olds understanding of complex
pragmatic communication. Experiment 1 demonstrates that children (N = 29)
better understand videotapes of a mother making indirect requests
to a child when the requests are accompanied by nonverbal pointing
behaviours. Experiment 2 uses a different methodology in which
children (N = 27) are actual participants rather than observers in order
to generalize the findings to naturalistic, face-to-face interactions. The
results from both experiments suggest that broader units of analysis
beyond the verbal message may be needed in studying children's
continuing understanding of pragmatic processes.
Novikov type inequalities for differential forms with non-isolated
zeros
Authors: BRAVERMAN MAXIM , FARBER MICHAEL
Published: July 2002

We generalize the Novikov inequalities for 1-forms in
two different directions:
first, we allow non-isolated critical points (assuming that
they are non-degenerate in
the sense of R. Bott) and, secondly, we strengthen the inequalities by
means of
twisting by an arbitrary flat bundle. The proof uses Bismut's
modification of the
Witten deformation of the de Rham complex; it is based on an explicit estimate
on
the lower part of the spectrum of the corresponding Laplacian.

In particular, we obtain a new analytic proof of the degenerate
Morse inequalities of Bott.
Ecotourism and conservation in Amazonian Perú: short-term and long-term challenges
Authors: YU DOUGLAS W. , HENDRICKSON THOMAS , CASTILLO ADA
Published: July 2002

Several authors have suggested that ecotourism can enhance the value of intact wildlands and thereby promote conservation. Two rainforest lodges dating from the 1970s and located in southeastern Amazonian Perú have been held up as early success stories in tourism-driven conservation, but a more recent assessment reveals that both lodges have since lost their rainforest reserves to encroachment. One of the major reasons for failure was that the national land laws in effect at the time did not allow the purchase of land titles. Recently, Perú has instituted a process for the purchase of land titles in the rainforest. One lodge has used the new land tenure laws with some success to create a rainforest reserve. The very attempt to buy land for purposes of conservation can promote encroachment and land-buying speculation, and the lodge's current agreement with its neighbours to provide a school in exchange for non-encroachment is fraught with moral hazards and appears unstable over the long term. Tourism can promote conservation primarily at the national level, and ecotourism projects in the Peruvian Amazon can stabilize land-use patterns at least in the short term. However, the conservation of habitat over the long-term will rest primarily on the ability of the State to enforce a consistent land use policy with regard to land tenure and Park protection.
On utility of inductive learning in multiobjective robust
design
Authors: FOROURAGHI BABAK
Published: July 2002

Most engineering design problems involve optimizing a number
of often conflicting performance measures in the presence
of multiple constraints. Traditional vector optimization
techniques approach these problems by generating a set
of Pareto-optimal solutions, where any specific objective
can be further improved only at the cost of degrading one
or more other objectives. The solutions obtained in this
manner, however, are only single points within the space
of all possible Pareto-optimal solutions and generally
do not indicate to designers how small deviations from
predicted design parameters settings affect the performance
of the product or the process under study.

In this paper we introduce a new approach to robust design
based on the concept of inductive learning with regression
trees. Given a set of training examples relating to a multiobjective
design problem, we demonstrate how a multivariate regression
tree can utilize an information-theoretic measure of covariance
complexity to capture optimal, tradeoff design surfaces.
The novelty of generating design surfaces as opposed to
traditional points in the design space is that now designers
are able to easily determine how the responses of a product
or process vary as design parameters change. This ability
is of paramount importance in situations where design parameter
settings need to be modified during the lifetime of a product/process
due to various economic or operational constraints. As
a result, designers will be able to select optimal ranges
for design parameters such that the product's performance
indices exhibit minimal or tolerable deviations from their
target values. To highlight the advantages of our methodology,
we present a multiobjective example that deals with optimum
design of an electric discharge machining (EDM) process.
A large outbreak of conjunctivitis caused by a single genotype of Neisseria gonorrhoeae distinct from those causing genital tract infections
Authors: MAK D. B. , SMITH D. W. , HARNETT G. B. , PLANT A. J.
Published: July 2002

Several epidemics of gonococcal conjunctivitis have occurred in Aboriginal populations in Central Australia. In 1997, the first outbreak in the Kimberley region of Western Australia occurred, spreading to Central Australia with a total of 447 cases. A genotyping method was applied directly to DNA extracted from patient samples to characterize the gonococcus causing the epidemic and to compare it with contemporaneous genital isolates. Those positive conjunctival specimens from Kimberley and Central Australia that could be genotyped were all indistinguishable, but were distinct from the genital gonococci, even when they shared the same auxotype and serotype. This suggested that the outbreak was due to a single genotype of Neisseria gonorrhoeae that had probably been carried between communities by infected individuals. We did not find evidence to support the existence of a genital reservoir of the types causing epidemic gonococcal conjunctivitis.
Distribution of the meningococcal insertion sequence IS1301
in clonal lineages of Neisseria meningitidis
Authors: HILSE R. , STOEVESANDT J. , CAUGANT D. A. , CLAUS H. , FROSCH M. , VOGEL U.
Published: July 2002

The distribution of the meningococcal insertion sequence IS1301 was analysed in 496 strains of
different serogroups and clonal lineages of Neisseria meningitidis, and in 64 neisserial strains
other than N. meningitidis. IS1301 was found in meningococci, but not in apathogenic Neisseria
sp. and Neisseria gonorrhoeae. The copy numbers of IS1301 varied between 2 and 17 per
genome. IS1301 positive strains were mostly found among the serogroups 29E, W135, X, and
Y. Clonal lineages of serogroup A, B, and C meningococci associated with epidemic
meningococcal disease were rarely positive for IS1301.
Salmonella in sub-Antarctica: low heterogeneity in salmonella serotypes in South Georgian seals and birds
Authors: PALMGREN H. , McCAFFERTY D. , ASPÁN A. , BROMAN T. , SELLIN M. , WOLLIN R. , BERGSTRÖM S. , OLSEN B.
Published: July 2002

The number of human visitors to Antarctica is increasing rapidly, and with it a risk of
introducing infectious organisms to native animals. To study the occurrence of salmonella
serotypes in sub-Antarctic wildlife, faecal samples were collected from gentoo penguins,
macaroni penguins, gray-headed albatrosses, black-browed albatrosses and Antarctic fur seals
on Bird Island in the South Georgian archipelago during the austral summer of 1996 and 1998.
In 1996, S. havana, S. typhimurium and S. enteritidis were isolated from 7% of gentoo
penguins and 4% of fur seals. In 1998, however, 22% of fur seals were found to be infected
with S. havana, S. enteritidis and S. newport.
All isolates, except one, showed identical pulsed-field
gel electrophoresis-patterns within each serotype, irrespective of sampling year and animal
reservoir. No significant antibiotic resistance was found. The very low heterogeneity in the
salmonella isolates found could either indicate a high genetic adaptation of the bacteria to the
environment or a recent introduction of salmonella into the area.
Conceptualizing mental disorders in children: Where have we been and where are

we going?
Authors: SILK JENNIFER S. , NATH SANJAY R. , SIEGEL LORI R. , KENDALL PHILIP C.
Published: July 2002

Conceptions of mental illness in children are bound by cultural and social conventions of what

constitutes healthy and unhealthy development. To understand current conceptualizations of

disorders in children, we review the history of these conceptualizations from three intertwined

perspectives: a sociopolitical history of American children and families, the history of the mental

health fields and scientific disciplines involved in diagnosing children, and the evolution of

children's role in the Diagnostic and Statistical Manual of Mental Disorders. We

review where the field has been in its conception of childhood mental illness throughout the past

century, where we believe it is now, and raise questions about the direction in which child

diagnosis may be headed as we enter the new millennium. We conclude with social policy

recommendations based on theory and research regarding mental disorders in children.
Relationship of prenatal cocaine exposure and maternal postpartum psychological distress

to child developmental outcome
Authors: SINGER LYNN , ARENDT ROBERT , FARKAS KATHLEEN , MINNES SONIA , HUANG JIE , YAMASHITA TOYOKO
Published: July 2002

Maternal cocaine use during pregnancy can affect the infant directly through toxic effects or

indirectly through cocaine's influence on maternal psychological status. We followed 160

cocaine exposed and 56 nonexposed infants and their mothers identified at birth through

interview and/or urine screen. Although cocaine exposure defined the groups, infant

exposure to alcohol, marijuana, and tobacco was allowed to vary. Infants were 99% African

American and poor. All mothers completed the Brief Symptom Inventory (BSI) and infants were

given the Bayley Scales of Mental (MDI) and Motor (PDI) Development at a mean corrected age

of 17 ± 8 months. Both MDIs (94 ± 17 vs. 103 ± 16) and PDIs (101

± 16 vs. 108 ± 12) were lower for cocaine exposed infants. Psychological

distress was greater in cocaine using mothers. Hierarchical multiple regression was used to assess

the relative effects of gestational age, maternal psychological distress, and cocaine and polydrug

exposure on infant outcomes. Both psychological distress and cocaine and alcohol exposure

predicted lower MDIs after controlling for prematurity. Neither psychological distress nor

alcohol exposure predicted motor outcome, while cocaine had a significant effect. Tobacco and

marijuana exposure were unrelated to outcome. These findings provide further support for direct

effects of cocaine and alcohol on infant development, as well as highlight the need for studies to

document maternal psychological factors, which may increase child risk for poorer

outcomes.
Factors associated with abusive relationships among maltreated and nonmaltreated
youth
Authors: WOLFE DAVID A. , WEKERLE CHRISTINE , REITZEL–JAFFE DEBORAH , LEFEBVRE LORRIE
Published: July 2002

This study sought to understand how experiences of maltreatment occurring prior to 12 years
of age affect adolescent peer and dating relationships. A school-based sample of 15-year-olds
was divided into maltreated (n = 132) and nonmaltreated (n = 227)
subgroups based on self-reported maltreatment. These two groups were then compared on two
theoretically determined dimensions of adjustment (i.e., interpersonal sensitivity/hostility;
personal resources) and self- and teacher-report measures of peer and dating relationships.
Findings supported the hypothesis that maltreated youths significantly differed from
nonmaltreated youths in terms of adjustment problems as well as conflict with dating partners
and close friends. Maltreated youths reported significantly more verbal and physical abuse both
toward and by their dating partners, and were seen by teachers as engaging in more acts of
aggression and harassment toward others. In regression analyses, the significant association
between maltreatment and dating conflict for males was strengthened by including adjustment
dimensions in the equation; for females, adjustment variables mediated the association between
maltreatment and dating conflict. Results are discussed in relation to a maladaptive interpersonal
trajectory for maltreated children, wherein a violent interactional dynamic in adolescent close
relationships may be setting the stage for violence in intimate partnerships.
A functional description of TEX's formula layout
Authors: HECKMANN REINHOLD , WILHELM REINHARD
Published: July 2002

While the quality of the results of TEX's

mathematical formula layout algorithm is convincing,

its original description is hard to understand since

it is presented as an imperative program

with complex control flow and destructive manipulations of

the data structures representing

formulae. In this paper, we present a re-implementation of

TEX's formula layout algorithm in

the functional language SML, thereby providing a more

readable description of the algorithm,

extracted from the monolithical TEX system.
Selected papers from EUROCALL 2000
Authors: DELCLOQUE PHILIPPE
Published: July 2002

This volume brings together a selection of articles presented
at the EUROCALL 2000 Conference which took place in Dundee from 31 August 2000 for
three days. What distinguished the millennium conference from all previous
successful gatherings was that it was the venue for the first ever showing of
‘An Illustrated History of Computer Assisted Language Learning’, a
Year 2000 initiative which had been supported not just by EUROCALL but also by
CALICO and the rest of the world CALL community which was represented on the
large panel of experts responsible for vetting my efforts as editor.
Aging of the urogenital system
Authors: Verdejo Bravo Carlos
Published: July 2002

In this review, the principal morphological and functional changes which occur
in relationship to aging in both the genital tract and lower urinary tract are discussed.
Aging of the upper urinary tract is not considered.

Much of the evidence for age-related changes comes from cross-sectional studies
with their inherent methodological limitations. Furthermore, it is difficult to
accept ‘normal aging’ criteria that do not take into consideration
the role of the acute and chronic disease so prevalent in elderly people. Thus, more
longitudinal studies are needed in order to provide a more exact analysis of the
influence of aging on the urogenital system, as for all other systems of the body.
The Politics of the Family in Twentieth-Century Europe
Authors: Ginsborg Paul
Published: July 2002

This article aims to offer a first overview of family politics in twentieth-century Europe. The term ‘family politics’ is here taken to imply not just family policies – what states do for, or to, families – but, more broadly, the relations between individuals, families, civil society and the state. Four different visions of family politics, at different moments of the century, are analysed in detail: that of the Bolsheviks in the early years of the Russian Revolution; that of the great dictators (Hitler, Stalin, Mussolini, Franco) from the 1920s to the 1940s; that of Catholicism in the central decades of the century; and finally that of democracy, from 1945 onwards. It is argued that in each of these instances there emerges a strikingly different configuration of the relations in question (individual–family–civil society–state). For many of the Bolsheviks the family itself was the target of attack, while the individual was to be subsumed into a collectivised society. For the great dictators civil society was swiftly eliminated and the family was formally exalted, but the crucial relationships became those between the authoritarian state and regimented individuals. For the Catholic Church of Pius XII the principal menace to the Christian family was seen to come from the state on the one hand and individualism on the other; the family and an integrist society were to be the principal links of his chain. Democracy alone, albeit imperfectly, has held fast to all four elements, trying in different ways in different countries to strike a balance between them.
Abstracts of Note: The Bioethics Literature
Authors: Iserson Kenneth V.
Published: July 2002

This section is meant to be a mutual effort. If you find an article
you think should be abstracted in this section, do not be
bashful—submit it for consideration to feature editor Kenneth V.
Iserson care of CQ. If you do not like the editorial comments,
this will give you an opportunity to respond in the letters section.
Your input is desired and anticipated.
Desperately Seeking Difference
Authors: BLACKSHER ERIKA
Published: July 2002

Critics from a variety of camps have argued that
bioethics has suffered an indifference to “difference.”
Cases have been described as thin and the selves inhabiting
them hollow. This criticism has been driven at least in
part by a reworked conception of the self. The rational
and autonomous self that once dominated bioethics discourse
has been replaced with a more “textured” self,
a self embedded in stories, relationships, families, communities,
cultures, and other “thick” particularity—such
as race, ethnicity, gender, sexual orientation, religion,
and experience generally. The import of such a self is
not simply descriptive accuracy; these contextual details—these
differences—matter. They matter because they figure
importantly into our ethical analyses of cases, affecting,
for example, how we interact with and treat patients. And
with this shift has come increasing attention to the processes
of moral inquiry that enable inquirers to gather all of
this moral information and find their way from complex
cases to context-sensitive responses.
Australian Animal Ethics Committees: We Have Come a Long Way
Authors: ANDERSON WARWICK P. , PERRY MICHAEL A.
Published: July 2002

Twenty years ago, Australian biomedical researchers
took the first steps along a pathway toward common ground
with opponents of the use of animals in science. Leaders
of Australian medical research at that time saw the necessity
of established science facing the ethical and political
challenges that a revived antivivisectionist movement was
mounting in the late 1970s and the 1980s.
Independent Transversals and Independent Coverings in Sparse

Partite Graphs
Authors: YUSTER RAPHAEL
Published: July 2002

An [n, k, r]-partite graph

is a graph whose vertex set, V, can be partitioned into n

pairwise-disjoint independent sets,

V1, …, Vn, each

containing exactly k vertices, and the subgraph induced by

Vi ∪ Vj

contains exactly r independent edges, for 1 [les ] i

< j [les ] n. An independent transversal

in an [n, k, r]-partite graph is

an independent set,

T, consisting of n vertices, one from each

Vi. An independent covering is a

set of k pairwise-disjoint independent transversals. Let

t(k, r) denote the maximal n for which
every

[n, k, r]-partite graph contains an
independent

transversal. Let c(k, r) be the maximal

n for which

every [n, k, r]-partite graph

contains an independent

covering. We give upper and lower bounds for these parameters.

Furthermore, our bounds are constructive. These results improve and

generalize previous results of Erdo″s, Gyárfás and

Łuczak [5], for the case of graphs.
The Storm‐Structure‐Severity method for the identification of convective storm characteristics with conventional weather radar
Authors: Visser Petrus J M
Published: July 2002

Radar reflectivity information is often displayed in two dimensions, making it difficult to extract the structural characteristics of convective storms. The maximum radar reflectivity and the vertical profile of liquid water distribution in a vertical column of a convective cell is used to determine a structural and intensity classification of the cell. The application of this Storm‐Structure‐Severity classification is demonstrated by investigating a tornado event on 15 November 1998 in Harrismith, South Africa, by using volume‐scanned reflectivity data from the S‐band MRL‐5 radar. The regions of convective development, decay and mesocyclone evolution are identified with this classification. The method is able to extract the three‐dimensional structural information of convective storms embedded in volume‐scanned reflectivity data and present it in a simple display format. Copyright © 2001 Royal Meteorological Society
Time, tense and aspect in natural language database interfaces
Authors: ANDROUTSOPOULOS ION , RITCHIE GRAEME , THANISCH PETER
Published: July 2002

Most existing Natural Language Database Interfaces (NLDB) were
designed to be used with
database systems that provide very limited facilities for manipulating
time-dependent data,
and they do not support adequately temporal linguistic mechanisms (verb
tenses, temporal
adverbials, temporal subordinate clauses, etc.). The database community
is becoming
increasingly interested in temporal database systems, which are intended
to store and manipulate
in a principled manner information not only about the present, but also
about the past and
future. When interfacing to temporal databases, supporting temporal linguistic
mechanisms
becomes crucial.

We present a framework for constructing Natural Language Interfaces
for Temporal
Databases (NLTDB), which draws on research in tense and aspect theories,
temporal logics
and temporal databases. The framework consists of a temporal intermediate
representation
language, called TOP, an HPSG grammar that maps a wide range of questions
involving
temporal mechanisms to appropriate TOP expressions, and a provably correct
method for
translating from TOP to TSQL2, TSQL2 being a recently proposed temporal
extension of the
SQL database language. This framework was employed to implement a prototype
NLTDB.
THE VALUE OF SELF-PRACTICE OF COGNITIVE THERAPY TECHNIQUES AND SELF-REFLECTION IN THE TRAINING OF COGNITIVE THERAPISTS
Authors: Bennett-Levy James , Turner Frederick , Beaty Taryn , Smith Michelle , Paterson Bethany , Farmer Sarah
Published: July 2002

Recent publications have suggested that practising cognitive therapy (CT) techniques on oneself may be
valuable in the development of cognitive therapists' clinical skills. The present study asks: Is this useful? If so, in
what ways? We report a qualitative study of the experience of trainees undertaking a CT training course, which
included an explicit self-practice (SP) and self-reflection (SR) component. Key features of the learning process were:
(i) experiencing cognitive techniques from the client's perspective, and (ii) reflecting on this experience that led to
(iii) a “deeper sense of knowing” of CT practices. The primary learning outcome was an enhancement of therapeutic
understandings, which trainees reported to be both professionally and personally useful. Professionally, they reported
deeper understanding of the therapist's role, the cognitive model and change processes. Personally, SP/SR led to
greater understanding of themselves, and to the perception of CT as a useful tool for personal change. The data also
suggested two other positive learning outcomes: an enhancement of therapist skills and therapist self-concept. We
conclude that SP/SR may be a valuable component in CT training. Guidelines and recommendations for inclusion of
SP/SR in training courses are discussed.
INFORMATION DYNAMICS IN FINANCIAL MARKETS
Authors: de Fontnouvelle Patrick
Published: July 2002

A noisy rational expectations model of asset trading is extended to incorporate costs of information acquisition and expectation formation. Because of the information costs, how much information to acquire becomes an important decision. Agents make this decision by choosing an expectations strategy about the future value of information. Because expectation formation is costly, agents often choose strategies that are simpler (and thus cheaper) than rational expectations. The model's dynamics can be expressed in terms of the market precision, which represents the amount of information acquired by the average agent. Under certain conditions, market precision follows an unstable and highly irregular time path. This irregularity directly affects observable market quantities. In particular, simulated time series for return volatility and trading volume display a copersistence similar to that found in actual financial data.
Public Opinion and Its Impacts on the 2000 HR election
Authors: Kabashima Ikuo
Published: July 2002

This short note analyzes how the public in Japan evaluates the performance of the cabinet and the two major parties, the Liberal Democratic Party (LDP) and the Democratic Party of Japan (DP), and their impacts on the 2000 House of Representatives election held on 25 June.
Changes in activities of antioxidant enzymes and lipoxygenase during growth of sunflower seedlings from seeds of different vigour
Authors: Bailly Christophe , Bogatek-Leszczynska Renata , Côme Daniel , Corbineau Françoise
Published: July 2002

The aim of this study was to investigate whether there was a relationship between growth of sunflower seedlings at 15°C in the dark and activities of enzymes involved in scavenging of reactive oxygen species (ROS), especially superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR), or in production of free radicals, namely lipoxygenase (LOX). Untreated control seeds were compared with seeds exposed to accelerated ageing (5 d at 45°C and 100% relative humidity), osmopriming (7 d at 15°C with a polyethylene glycol (PEG) solution at –2 MPa) and accelerated ageing followed by priming. Accelerated ageing decreased seed germinability and slowed down hypocotyl growth, whereas priming resulted in an increase in germination rate and enhanced seedling development. Osmopriming of aged seeds almost completely restored the initial rate of germination and seedling growth. The activity of all the enzymes studied increased during seed germination and seedling development, except that of SOD. Seed imbibition or radicle protrusion were related mainly with an increase in CAT activity and, to a lesser extent, in GR activity. Increase of LOX activity was clearly associated with the onset of hypocotyl elongation. However, in all cases, malondialdehyde measurements did not reveal intense lipid peroxidation. Priming induced a marked stimulation of CAT and GR during seed imbibition or very early during seedling development, as compared to the control seedlings and particularly to the seedlings generated by aged seeds. Hydrogen peroxide (H2O2) contents of seeds and seedlings were closely correlated to the activities of CAT and GR and to the kinetics of seedling development. The results obtained establish a clear relationship between sunflower seed vigour and ROS scavenging.
The Sir1 protein's association with a silenced chromosome domain
Authors: Gardner Kelly A. , Fox Catherine A.
Published: July 2002

Silencing of the cryptic mating-type locusHMRrequires recognition of a small DNA sequence element, theHMR-E silencer, by the Sir1p, one of four Sir proteins required for the assembly of silenced chromatin domains inSaccharomyces cerevisiae. The Sir1p recognizes the silencer through interactions with the origin recognition complex (ORC), a protein complex that binds the silencer DNA directly. Sir1p was physically associated withHMRin chromatin, and this association required a Sir1p–ORC interaction, suggesting that it reflected the Sir1p silencer-recognition function required for silencing. Sir1p was not associated with nonsilencer replication origins that bind the ORC, indicating that a Sir1p–ORC interaction is confined to silencers. Significantly, the otherSIRgenes were required for Sir1p's association withHMR. Thus, multiple protein contacts required for and unique to silent chromatin may confine a Sir1p–ORC interaction to silencers. The Sir1p was present at extremely low concentrations in yeast cells yet was associated withHMRat all stages of the cell cycle examined. These data provide insights into the mechanisms that establish and restrict the assembly of silenced chromatin to only a few discrete chromosomal domains.
Drosophila Fos mediates ERK and JNK signals via distinct phosphorylation sites
Authors: Ciapponi Laura , Jackson David B. , Mlodzik Marek , Bohmann Dirk
Published: July 2002

During Drosophila development Fos acts downstream from the JNK pathway. Here we show that it can also mediate ERK signaling in wing vein formation and photoreceptor differentiation.Drosophila JNK and ERK phosphorylate D-Fos with overlapping, but distinct, patterns. Analysis of flies expressing phosphorylation site point mutants of D-Fos revealed that the transcription factor responds differentially to JNK and ERK signals. Mutations in the phosphorylation sites for JNK interfere specifically with the biological effects of JNK activation, whereas mutations in ERK phosphorylation sites affect responses to the EGF receptor–Ras–ERK pathway. These results indicate that the distinction between ERK and JNK signals can be made at the level of D-Fos, and that different pathway-specific phosphorylated forms of the protein can elicit different responses.
Parallel Acquisition of Awareness and Trace Eyeblink Classical Conditioning
Authors: Manns Joseph R. , Clark Robert E. , Squire Larry R.
Published: July 2002

Trace eyeblink conditioning (with a trace interval ≥500 msec) depends on the integrity of the hippocampus and requires that participants develop awareness of the stimulus contingencies (i.e., awareness that the conditioned stimulus [CS] predicts the unconditioned stimulus [US]). Previous investigations of the relationship between trace eyeblink conditioning and awareness of the stimulus contingencies have manipulated awareness or have assessed awareness at fixed intervals during and after the conditioning session. In this study, we tracked the development of knowledge about the stimulus contingencies trial by trial by asking participants to try to predict either the onset of the US or the onset of their eyeblinks during differential trace eyeblink conditioning. Asking participants to predict their eyeblinks inhibited both the acquisition of awareness and eyeblink conditioning. In contrast, asking participants to predict the onset of the US promoted awareness and facilitated conditioning. Acquisition of knowledge about the stimulus contingencies and acquisition of differential trace eyeblink conditioning developed approximately in parallel (i.e., concurrently).
High-Level Production of γ-Linolenic Acid in Brassica juncea Using a Δ6 Desaturase from Pythium irregulare
Authors: Hong Haiping , Datla Nagamani , Reed Darwin W. , Covello Patrick S. , MacKenzie Samuel L. , Qiu Xiao
Published: July 2002

γ-Linolenic acid (GLA), a nutritionally important fatty acid in mammals, is synthesized by a Δ6 desaturase. Here, we report identification of PiD6, a new cDNA from the oleaginous fungus, Pythium irregulare, encoding a 459-amino acid protein that shares sequence similarity to carboxyl-directed desaturases from various species. Expression ofPiD6 in yeast (Saccharomyces cerevisiae) revealed that it converts exogenously supplied linoleic acid into GLA, indicating that it encodes a Δ6 fatty acid desaturase. Expression of the desaturase in Brassica juncea under the control of the Brassica napus napin promoter resulted in production of three Δ6 unsaturated fatty acids (18:2–6, 9; 18:3–6, 9, 12; and 18:4–6, 9, 12, 15) in seeds. Among them, GLA (18:3–6, 9, 12) is the most abundant and accounts for up to 40% of the total seed fatty acids. Lipid class and positional analysis indicated that GLA is almost exclusively incorporated into triacylglycerol (98.5%) with only trace amounts found in the other lipids. Within triacylglycerols, GLA is more abundant at the sn-2 position.
Severity of Mutant Phenotype in a Series of Chlorophyll-Deficient Wheat Mutants Depends on Light Intensity and the Severity of the Block in Chlorophyll Synthesis
Authors: Falbel T. G. , Meehl J. B. , Staehelin L. A.
Published: July 2002

Analyses of a series of allelic chlorina mutants of wheat (Triticum aestivum L.), which have partial blocks in chlorophyll (Chl) synthesis and, therefore, a limited Chl supply, reinforce the principle that Chl is required for the stable accumulation of Chl-binding proteins and that only reaction centers accumulate when the supply of Chl is severely limited. Depending on the rate of Chl accumulation (determined by the severity of the mutation) and on the rate of turnover of Chl and its precursors (determined by the environment in which the plant is grown), the mutants each reach an equilibrium of Chl synthesis and degradation. Together these mutants generate a spectrum of phenotypes. Under the harshest conditions (high illumination), plants with moderate blocks in Chl synthesis have membranes with very little Chl and Chl-proteins and membrane stacks resembling the thylakoids of the lethal xantha mutants of barley grown at low to medium light intensities (which have more severe blocks). In contrast, when grown under low-light conditions the same plants with moderate blocks have thylakoids resembling those of the wild type. The wide range of phenotypes of Chl b-deficient mutants has historically produced more confusion than enlightenment, but incomparable growth conditions can now explain the discrepancies reported in the literature.
Antisense Expression and Overexpression of Biotin Carboxylase in Tobacco Leaves
Authors: Shintani D. , Roesler K. , Shorrosh B. , Savage L. , Ohlrogge J.
Published: July 2002

The plastid acetyl-coenzyme A carboxylase (ACCase) catalyzes the first committed step of fatty acid synthesis and in most plants is present as a heteromeric complex of at least four different protein subunits: the biotin carboxylase (BC), the biotin carboxyl carrier protein, and the α- and [beta] subunits of the carboxyltransferase. To gain insight into the subunit organization of this heteromeric enzyme complex and to further evaluate the role of ACCase in regulating fatty acid synthesis, BC expression was altered in transgenic plants. Tobacco (Nicotiana tabacum) was transformed with antisense-expression and overexpression tobacco BC constructs, which resulted in the generation of plants with BC levels ranging from 20 to 500% of wild-type levels. Tobacco plants containing elevated or moderate decreases in leaf BC were phenotypically indistinguishable from wild-type plants. However, plants with less than 25% of wild-type BC levels showed severely retarded growth when grown under low-light conditions and a 26% lower leaf fatty acid content than wild-type plants. A comparison of leaf BC and biotin carboxyl carrier protein levels in plants with elevated and decreased BC expression revealed that these two subunits of the plastid ACCase are not maintained in a strict stoichiometric ratio.
Phytochrome B and the Regulation of Circadian Ethylene Production in Sorghum1
Authors: Finlayson Scott A. , Lee In-Jung , Morgan Page W.
Published: July 2002

The sorghum (Sorghum bicolor L. Moench) cultivar 58M, which contains the null mutant phytochrome B gene, shows reduced photoperiodic sensitivity and exhibits a shade-avoidance phenotype. Ethylene production by seedlings of wild-type and phytochrome B mutant cultivars was monitored every 3 h, and both cultivars were found to produce ethylene in a circadian rhythm, with peak production occurring during the day. The phytochrome B mutant produces rhythmic peaks of ethylene with approximately 10 times the amplitude of the wild-type counterpart with the same period and diurnal timing. The source of the mutant's additional ethylene is the shoot. The diurnal rhythm can be produced with either light or temperature cycles; however, both light and temperature cycles are required for circadian entrainment. The temperature signal overrides the light signal in the production of diurnal rhythms, because seedlings grown under thermoperiods reversed with the photoperiod produced ethylene peaks during the warm nights. To examine the effect of extreme shading on ethylene production, seedlings were grown under dim, far-red-enriched light. This treatment duplicated the phytochrome B mutant's shade-avoidance phenotype in the wild type and caused the wild type to produce ethylene peaks similar to those observed in the mutant. The results confirm that phytochrome B is not required for proper function of circadian timing, but it may be involved in modulating physiological rhythms driven by the biological clock oscillator.
Transport, Compartmentation, and Metabolism of Homoserine in Higher Plant Cells
Authors: Aubert Serge , Curien Gilles , Bligny Richard , Gout Elisabeth , Douce Roland
Published: July 2002

The transport, compartmentation, and metabolism of homoserine was characterized in two strains of meristematic higher plant cells, the dicotyledonous sycamore (Acer pseudoplatanus) and the monocotyledonous weedEchinochloa colonum. Homoserine is an intermediate in the synthesis of the aspartate-derived amino acids methionine, threonine (Thr), and isoleucine. Using 13C-nuclear magnetic resonance, we showed that homoserine actively entered the cells via a high-affinity proton-symport carrier (Kmapproximately 50–60 μm) at the maximum rate of 8 ± 0.5 μmol h−1 g−1 cell wet weight, and in competition with serine or Thr. We could visualize the compartmentation of homoserine, and observed that it accumulated at a concentration 4 to 5 times higher in the cytoplasm than in the large vacuolar compartment.31P-nuclear magnetic resonance permitted us to analyze the phosphorylation of homoserine. When sycamore cells were incubated with 100 μm homoserine, phosphohomoserine steadily accumulated in the cytoplasmic compartment over 24 h at the constant rate of 0.7 μmol h−1 g−1 cell wet weight, indicating that homoserine kinase was not inhibited in vivo by its product, phosphohomoserine. The rate of metabolism of phosphohomoserine was much lower (0.06 μmol h−1 g−1 cell wet weight) and essentially sustained Thr accumulation. Similarly, homoserine was actively incorporated by E. colonum cells. However, in contrast to what was seen in sycamore cells, large accumulations of Thr were observed, whereas the intracellular concentration of homoserine remained low, and phosphohomoserine did not accumulate. These differences with sycamore cells were attributed to the presence of a higher Thr synthase activity in this strain of monocot cells.
Calcium-Dependent Protein Phosphorylation May Mediate the Gibberellic Acid Response in Barley Aleurone1
Authors: Ritchie Sian , Gilroy Simon
Published: July 2002

Peptide substrates of well-defined protein kinases were microinjected into aleurone protoplasts of barley (Hordeum vulgare L. cv Himalaya) to inhibit, and therefore identify, protein kinase-regulated events in the transduction of the gibberellin (GA) and abscisic acid signals. Syntide-2, a substrate designed for Ca2+- and calmodulin (CaM)-dependent kinases, selectively inhibited the GA response, leaving constitutive and abscisic acid-regulated events unaffected. Microinjection of syntide did not affect the GA-induced increase in cytosolic [Ca2+], suggesting that it inhibited GA action downstream of the Ca2+ signal. When photoaffinity-labeled syntide-2 was electroporated into protoplasts and cross-linked to interacting proteins in situ, it selectively labeled proteins of approximately 30 and 55 kD. A 54-kD, soluble syntide-2 phosphorylating protein kinase was detected in aleurone cells. This kinase was activated by Ca2+ and was CaM independent, but was inhibited by the CaM antagonistN-(6-aminohexyl)-5-chloro-1-naphthalene-sulfonamide (250 μm), suggesting that it was a CaM-domain protein kinase-like activity. These results suggest that syntide-2 inhibits the GA response of the aleurone via an interaction with this kinase, implicating the 54-kD kinase as a Ca2+-dependent regulator of the GA response in these cells.
Association of Ferredoxin-NADP Oxidoreductase with the Chloroplastic Pyridine Nucleotide Dehydrogenase Complex in Barley Leaves1
Authors: José Quiles Marı́a , Cuello Juan
Published: July 2002

Barley (Hordeum vulgare L.) leaves were used to isolate and characterize the chloroplast NAD(P)H dehydrogenase complex. The stroma fraction and the thylakoid fraction solubilized with sodium deoxycholate were analyzed by native polyacrylamide gel electrophoresis, and the enzymes detected with NADH and nitroblue tetrazolium were electroeluted. The enzymes electroeluted from band S from the stroma fraction and from bands T1 (ET1) and T2 from the thylakoid fraction solubilized with sodium deoxycholate had ferredoxin-NADP oxidoreductase (FNR; EC 1.18.1.2) and NAD(P)H-FeCN oxidoreductase (NAD[P]H-FeCNR) activities. Their NADPH-FeCNR activities were inhibited by 2′-monophosphoadenosine-5′-diphosphoribose and by enzyme incubation with p-chloromercuriphenylsulfonic acid (p-CMPS), NADPH, and p-CMPS plus NADPH. They presented Michaelis constant NADPH values that were similar to those of FNRs from several sources. Their NADH-FeCNR activities, however, were not inhibited by 2′-monophosphoadenosine-5′-diphosphoribose but were weakly inhibited by enzyme incubation with NADH, p-CMPS, and p-CMPS plus NADH. We found that only ET1 contained two polypeptides of 29 and 35 kD, which reacted with the antibodies raised against the mitochondrial complex I TYKY subunit and the chloroplast ndhA gene product, respectively. However, all three enzymes contained two polypeptides of 35 and 53 kD, which reacted with the antibodies raised against barley FNR and the NADH-binding 51-kD polypeptide of the mitochondrial complex I, respectively. The results suggest that ET1 is the FNR-containing thylakoidal NAD(P)H dehydrogenase complex.