bluuebunny/crossref_metadata_2025 huggingface dataset:
Tandem language learning via e-mail: from motivation to autonomy
Authors: USHIODA EMA
Published: July 2002

This paper examines the affective dimension of tandem language learning via e-mail.
It begins by highlighting some of the obstacles to this mode of learning, including
organisational and pedagogical issues as well as the particular issues confronting
learners. Drawing on a small body of empirical data, it explores the interactions
between these issues and what learners perceive to be intrinsically motivating about
tandem learning. It concludes by suggesting that affective learning experience has a
potentially powerful role to play in fostering the development of learner autonomy
through the reciprocity on which successful tandem learning is founded.
Safe mobility for older people
Authors: O’Neill Desmond
Published: July 2002

Driving: a new geriatric giant?

Over the last fifty years geriatric medicine has promoted the concept that functional loss in older people is primarily a health issue. For a major loss of function, such as incontinence or immobility, we recognize the need for detection, investigation and treatment. The diagnostic / therapeutic / rehabilitation paradigm takes precedence over the prosthetic approach. Not only do we appreciate the benefits of an interdisciplinary assessment, but we are also accustomed to estimating risk and competence when making decisions about discharging frail older people back to their home environment.
Classification of the dementias
Authors: Neary David
Published: July 2002

Dementia is not a disease. It is the neuropsychological deficit which results from chronic brain disease or encephalopathy. Dementias may be nonprogressive, for example resulting from brain trauma or cerebral hypoxia, or progressive, resulting from intrinsic, extrinsic or metabolic cerebral disorder. The progressive encephalopathies, in particular those resulting from intrinsic brain disease, form the subject of this review.
Algorithms for categorical equivalence
Authors: BERGMAN CLIFFORD , BERMAN JOEL
Published: July 2002

This paper provides an algorithm that, given two finite algebras

A and B each of arbitrary
finite similarity type, determines whether or not A and B

are categorically equivalent.
Although the algorithm is not practical in general, we consider some conditions
on the
algebras that improve its performance.
EVIDENCE FOR INTROGRESSIVE HYBRIDIZATION BASED ON CHLOROPLAST DNA POLYMORPHISMS AND MORPHOLOGICAL VARIATION IN WILD EVERGREEN AZALEA POPULATIONS OF THE KIRISHIMA MOUNTAINS, JAPAN
Authors: KOBAYASHI N. , HANDA T. , YOSHIMURA K. , TSUMURA Y. , ARISUMI K. , TAKAYANAGI K.
Published: July 2002

For the purpose of determining the origin of horticultural evergreen azalea cultivars, this study was focused on the natural populations of azalea in Kyushu (south main island of Japan). The Kirishima mountains, the volcanic mountain mass in Kyushu, are an important centre of diversity for the Japanese evergreen azaleas. Rhododendron kiusianum Makino grows above 1000m alt., whereas R. kaempferi Planch. is distributed below 600m alt. Putative natural hybrid populations of these two species are found in the intermediate region (1000–600m alt.). These two species have been clearly distinguished by their respective morphological features. Rhododendron kiusianum has small pink-purple flowers and small elliptical leaves, whereas R. kaempferi has larger red-orange flowers with dark blotches and large oblong leaves. Interspecific hybrids show phenotypes within the range of the two species, especially with regard to flower colour and leaf shape. A morphological cline of these characteristics corresponding to altitude has been observed between these two species. PCR-RFLP analysis of chloroplast DNA detected specific bands for the two species in the 16S rDNA region when digested with HhaI restriction enzyme. Populations of interspecific hybrids were composed of individuals that had a banding pattern of either R. kiusianum or R. kaempferi. This indicates that R. kiusianum and R. kaempferi are clearly distinct species. Furthermore, natural hybrid populations consist of individuals that have one of two cpDNA. Some individuals in the populations of R. kiusianum (T-1430 and T-1030) possess the cpDNA pattern of R. kaempferi, which suggests that cytoplasmic introgression has occurred in the populations of R. kiusianum from R. kaempferi.
BRAZILIAN SPECIES OF VIGUIERA (ASTERACEAE) EXHIBITLOW LEVELS OF ITS SEQUENCE VARIATION
Authors: SCHILLING E. E. , DA COSTA F. B. , LOPES N. P. , HEISE P. J.
Published: July 2002

The internal transcribed spacer (ITS) region of the nuclear ribosomal DNA was sequenced from 21 accessions of Viguiera from South America, including 14 from Brazil. Overall there was only a small amount of sequence variation, less than 3.4% among South American samples and less than 4.5% between the South American samples and the Mexican V. flava. Phylogenetic analysis revealed little divergence among the Brazilian samples of Viguiera. The low level of ITS sequence variation was in striking contrast to the taxonomic diversity and chemical variability that have been reported for Viguiera in Brazil. The low level of sequence variation suggests that, despite its clear morphological and phytochemical adaptations to the cerrado, Viguiera is probably a relatively recent addition (less than 3 million years) to the flora of this area.
RHODODENDRON LORANTHIFLORUM (ERICACEAE) FROM MAINLANDNEW GUINEA. A DISTRIBUTIONAL RECORD AND NEW SUBSPECIES
Authors: TAKEUCHI W.
Published: July 2002

Rhododendron loranthiflorum was previously regarded as an archipelagic endemic, with known stations in the Solomon Islands and New Britain. An exploratory survey of the Lakekamu Basin has now established the plant's presence on the southern side of the New Guinea mainland. The Lakekamu provenance represents a geographical disjunction distinguishable as a separate subspecies, and is formally described as subsp. lakekamuensis.
SEASONALLY DRY FORESTS OF TROPICAL SOUTH AMERICA: FROM FORGOTTENECOSYSTEMS TO A NEW PHYTOGEOGRAPHIC UNIT
Authors: PRADO D. E.
Published: July 2002

The Pleistocenic Arc, which must have originated from the climatic shifts in South America during the late Pleistocene, ranges from the Caatingas of north-eastern Brazil through south-eastern Brazil to the Paraguay and Paraná rivers confluence, into south-western Bolivia and north-western Argentina, and extends sporadically into dry Andean valleys of Peru or coastal western Ecuador. It is regarded as a new phytogeographic unit for South America, here named the Tropical Seasonal Forests Region, as it is characterized by a considerable number of endemic plant taxa at both generic and species level. The paradigm of the arc is the distribution pattern of Anadenanthera colubrina (Fabaceae), which, when superimposed on those of other woody species of seasonal forests, permits a reasonably accurate mapping of the new region, which might also have biogeographic implications for endemic bird taxa. The plant communities of this newly recognized unit are unique in their nature and floristic composition, when compared with other floristic areas of the continent by means of classic phytosociological and numerical analyses (PCA). These ecosystems have remained submerged within other vegetation units in South American phytogeography (such as the Chaquenian or Amazonian regions), and have been particularly neglected in conservation policies. An urgent call is made for these areas to be preserved before they disappear, because they are located in areas with some of the best agricultural soils of tropical South America, and therefore subject to clearing for farming.
Portugal's First Domino: ‘Pluricontinentalism’ and Colonial War in Guiné-Bissau, 1963–1974
Authors: MACQUEEN NORRIE
Published: July 2002

Portugal's presence in Guiné-Bissau through eleven years of intense guerrilla war was justified by the doctrine of ‘pluricontinentalim’. In this view concession to nationalist pressure in one part of the ‘indivisible state’ would lead inevitably to the collapse of the whole. The defence of Portuguese Guiné, therefore, was the price to be paid for the maintenance of the infinitely more valuable territories of Angola and Mozambique. While the Salazar regime was rigid in its adherence to this doctrine, some movement was detectable under his successor from 1968, Marcello Caetano. The governor-general in Guiné, General Spínola, was permitted to explore possibilities of negotiation. Politically insecure in the face of residual Salazarist power in the regime, however, Caetano abandoned this approach in 1972. This apparent loss of nerve would contribute to the overthrow of the Lisbon regime by its own military in 1974 – despite recently revealed secret talks between Lisbon and the Guinea nationalists on the very eve of the coup.
Television and the City: the Impact of Television in Milan, 1954–1960
Authors: Foot John
Published: July 2002

The early years of state television in Italy, which began transmission in 1954, have usually been viewed as crucial to the spread of mass culture through Italian society. In addition, these developments have essentially been seen in negative terms by historians and sociologists. This article explores these early years in detail for one, key, urban setting: Milan. Through an examination of the myriad and often hidden effects of television, the research attempts to draw out the contradictory and complicated impact of TV and its relationship with other media, the neighbourhood, the family, the home and daily life. The article also looks at the impact of one important quiz show in the 1950s and concludes with some reflections on the power of the media in the city in the 1990s.
Limits—The Role of the Law in Bioethical Decision
Making, by Roger B. Dworkin. Bloomington (IN): Indiana
University Press, 1996. 205 pp.
Authors: Rich Ben A.
Published: July 2002

Anyone with so much as a passing familiarity with
bioethics knows how significantly and persistently (at
least since mid-century) the law has insinuated itself
into healthcare and the process of bioethical decisionmaking.
Viewed from the insular perspective of traditional medical
practice and medical ethics, it is not surprising that
the “legalization” of the patient–physician
relationship and clinical judgment has been characterized
by some as pernicious. What is much more surprising, however,
is when a book by a professor of law evinces the same jaundiced
view of the role of law in this area. Nonetheless, the
“limits” that Professor Dworkin considers to
be inherent in the capacity of the law to resolve bioethical
issues are significant, and hence in his opinion the role
of the law should be severely circumscribed. This gloomy
portrait of the “havoc” wreaked by law upon
the landscape of medical practice, painted by a lawyer,
stands in stark contrast to an earlier and much more sympathetic
account offered by Columbia University historian and medical
humanities professor David J. Rothman in his 1991 book
Strangers at the Bedside, the informative subtitle
of which is A History of How Law and Bioethics Transformed
Medical Decision Making.
Euthanasia and Health Reform in Canada
Authors: STINGL MICHAEL
Published: July 2002

This paper examines the following line of argument
against allowing euthanasia in Canada: “[Sue] Rodriguez...
argued that she be given the able bodied person's freedom of
choice. But true choice requires equal support for a decision
to live. ... Were freedom of choice in fact a primary concern,
liberalized euthanasia legislation would require full levels of
mandated social support. ...”
Response to “Paradigms for Clinical Ethics Consultation
Practice” by Mark D. Fox, Glenn McGee, and Arthur
L. Caplan (CQ Vol 7, No 3)
Authors: Rudin Edward
Published: July 2002

Fox, McGee, and Caplan's “Paradigms for Clinical
Ethics Consultation Practice”, in the Summer 1998 issue
of CQ, evoked memories and an image.
Mixing Time for a Markov Chain on Cladograms
Authors: ALDOUS DAVID J.
Published: July 2002

A cladogram is a tree with labelled leaves and unlabelled degree-3 branchpoints. A certain
Markov chain on the set of n-leaf cladograms consists of removing a random leaf (and its
incident edge) and re-attaching it to a random edge. We show that the mixing time (time
to approach the uniform stationary distribution) for this chain is at least
O(n2) and at most O(n3).
A Note on a Problem by Welsh in First-Passage
Percolation
Authors: ALM SVEN ERICK
Published: July 2002

Consider first-passage percolation on the square lattice. Welsh,
who together with
Hammersley introduced the subject in 1963, has formulated a problem about
mean first-passage
times, which, although seemingly simple, has not been proved in any non-trivial

case. In this paper we give a general proof of Welsh's problem.
Placenta praevia and placenta praevia accreta – a review of aetiology, diagnosis and management
Authors: Groom Katie M , Paterson-Brown Sara
Published: July 2002

Placenta praevia describes a placenta which partially or completely lies within the lower segment of the uterus. It is a major cause of antepartum haemorrhage and when it obstructs the internal os prevents safe vaginal delivery of the fetus.
Optimisation of porcine oocyte activation following nuclear transfer
Authors: Tao Tao , Macháty Zoltán , Abeydeera Lalantha R. , Day Billy N. , Prather Randall S.
Published: July 2002

Experiments were conducted to examine the effects of (a) different activation methods, (b) incubation time in calcium-free medium and (c) bisbenzimide staining on the activation and subsequent development of pig oocytes. Oocytes were matured in vitro and activated by one of the following methods: combined thimerosal/dithiothreitol (DTT) treatment, calcium ionophore A23187 treatment followed by incubation in the presence of 6-dimethylaminopurine (6-DMAP), electroporation, and electroporation followed by incubation with cytochalasin B. There were no significant differences in the activation rate (ranging from 70.0% to 88.3%) and the percentage of cleaved embryos after activation (ranging between 48.8% and 58.8%) among the four treatment groups (p < 0.05). The rate of development to the blastocyst stage in oocytes activated by thimerosal/DTT (10.0%) or electroporation followed by cytochalasin B treatment (12.3%) was significantly higher (p < 0.05) than in the group activated with A23187/6-DMAP (2.5%). Both the activation rate and the rate of blastocyst formation in oocytes that were incubated in Ca2+-free medium for 8 h before thimerosal/DTT activation were significantly lower (p < 0.05) than in those incubated for 0, 1 or 4 h. Intracellular Ca2+ measurements revealed that the Ca2+ homeostasis in these oocytes were severely altered. Staining of oocytes with 5 μg/ml bisbenzimide for 2 h decreased the quality of blastocysts and increased the rate of degenerated embryos at day 6. Two activation protocols (thimerosal/DTT and electroproation) were used for activation after nuclear transfer; the rate of nuclear formation did not differ in the oocytes activated by the two different methods.
THE VICTORIAN GRAND SIÈCLE: IDEOLOGY AS ART HISTORY
Authors: Mansfield Elizabeth
Published: July 2002

The true greatness of this great century consists . . . not in its vain wars, and formal stage, and stilted eloquence, and pompous palaces, and grandiose art, but in the formation and working out of the political and social system of which these things were the first fruits. It is idle to indulge in academical discussions as to the merits of this system. We have inherited it, it has penetrated our lives in every direction, we act, we think under its invisible pressure, and its study is pregnant with teaching.

— Emilia Dilke, Art in the Modern State

FUSING AESTHETIC INQUIRY WITH POLITICAL THEORY, Emilia Dilke’s Art in the Modern State heralds a shift in the evolving discipline of art history. Published in 1888, the book succeeds her well-received The Renaissance of Art in France (1879) and anticipates by a decade her multi-volume study of the arts of eighteenth-century France. Methodologically, however, Art in the Modern State stands apart from her other books. Predicated upon the supposition that art — indeed all cultural production — derives from and serves the “invisible pressure” of ideology, the book points to a new direction in Victorian aesthetic theory. Specifically, the book offers the first direct application of Marxist philosophy in an art historical text. That this innovation met and continues to meet with critical as well as popular indifference appears, at first, extraordinary. Considered within the context of Victorian art writing and materialist art history, however, the sources of this critical neglect begin to emerge.
BLACK FIGURES/ENGLISH LANDSCAPE
Authors: Kaplan Cora
Published: July 2002

IN ONE OF HIS LAST CANVASES — worked on for some six years and unfinished at his death — the distinguished genre and landscape painter, William Mulready (1786–1863), famous for his depiction of children and childhood, produced one of the most resonant and complex images of race and Empire of the mid-nineteenth century.1 Titled The Toy Seller and set in an emblematic rural landscape, it displays a mother holding a child of between one and two years old, while a kneeling pedlar respectfully proffers a rattle from a basket of similarly humble toys (Figure 19). The infant, however, perversely refuses to be tempted. Its body and gaze are turned awkwardly away from the toy seller, its shrugged shoulders and unhappy expression graphically suggest the unease provoked by the stranger’s importunities, or perhaps merely his presence. Meanwhile the mother’s look is turned with gentle concern on the distressed child. The pedlar too looks towards the baby with a still amd practiced watchfulness, as if waiting for the mother to coax the child into a more receptive mood. The toy seller is black; the mother and child are white.
The impact of screening on road surface temperature
Authors: Bogren J , Gustavsson T , Karlsson M , Postgård U
Published: July 2002

The effect of screening on road surface temperatures is analysed using data from the Swedish road weather information system (RWIS) together with data from thermal mapping. The study deals with the analysis of temperature variations caused by shading of the road surface during clear daytime conditions and focuses on the relation between solar elevation and magnitude of road surface temperature differences between screened and sun‐exposed areas. Also included is an analysis of how the temperature differences during the day affect the establishment of temperature variations after sunset and the time it takes after sunset for temperature differences caused by shading to decline. The results show that the magnitude of road surface temperature differences between sun exposed and screened sites (RSTdiff) that develop during clear day conditions can be attributed to solar elevation (β) and can be expressed by the equation: RSTdiff = −2.7 + 0.46(β). A relationship between the daily maximum temperature difference and the preservation of the screening effect after sunset is observed. The effect after sunset can be described by: RSTdiff = A − B h + C h2 − D h3 − E h4 + F h5, where h is the time in hours after sunset and A to F are constants related to the time of the year at the actual site. Copyright © 2000 Royal Meteorological Society
The operational Australian ultraviolet index forecast 1997
Authors: Lemus‐Deschamps Lilia , Rikus Lawrie , Gies Peter
Published: July 2002

The Cooperative Research Centre for Southern Hemisphere Meteorology in collaboration with the Bureau of Meteorology has developed an ultraviolet index (UVI) forecast system to support the Australian UVI forecast issued to the public by the Bureau of Meteorology. In an effort to alert the public to the possibility of harmful levels of ultraviolet radiation the UVI forecast has been issued daily as part of the meteorological weather report since spring 1996. The predicted UVI indicates the amount of ultraviolet radiation that will reach the Earth's surface at local noon next day. The forecast includes the effects of cloud cover. The global clear sky UVI is calculated using a two‐stream radiative transfer model and a deterministic ozone forecast scheme. The system utilises meteorological fields from the global numerical weather forecast model of the Bureau of Meteorology. This paper describes the UVI forecast system, and its results are compared with observational data from the Australian Radiation Laboratory for several Australian cities for the period January–December 1997. Possible improvements are outlined since the UVI forecast system is the subject of ongoing development. Copyright © 1999 Royal Meteorological Society
In Memoriam
Authors: Adams Kenneth M.
Published: July 2002

Laird Cermak was to become President of INS in February 2000,
taking over the responsibilities for leading a scientific society
he loved and served for over a quarter of a century. In many ways
he embodied the very values the INS has always hoped to promote in
excellence of scholarship, keen interest in behavioral neurosciences,
and an easy and reflexive interdisciplinary citizenship. His name has
been synonymous with a distinctive line of intellectual inquiry in
amnesia and memory mechanisms for as long as I have been in
neuropsychology myself.
Long-term effects of high-dose zidovudine treatment on neuropsychological
performance in mildly symptomatic HIV-positive patients: Results of a
randomized, double-blind, placebo-controlled investigation
Authors: LLORENTE ANTOLIN M. , VAN GORP WILFRED G. , STERN MARTIN J. , GEORGE LANCE , SATZ PAUL , MARCOTTE THOMAS D. , CALVILLO GILBERT M. , HINKIN CHARLES H.
Published: July 2002

This study examined the treatment outcome of high-dose
(1500 mg/day) zidovudine (AZT) on neuropsychological (NP)
functioning (Trailmaking Test A & B, WAIS-R Digit Symbol,
and Rey Auditory Verbal Learning Test) across a 12-month
period in mildly symptomatic HIV-1 seropositive men (n
= 46 at entry) enrolled in a randomized, double-blind,
placebo-controlled trial (VA Cooperative Studies Program
#298). Neither short-term (0–6 months) nor long-term
(0–12 months) AZT administration revealed enhancement
in NP performance. The results suggest that, although AZT
may afford patients prophylactic benefits, protracted high-dose
AZT treatment does not improve NP functioning in mildly
symptomatic HIV-positive individuals. (JINS, 2001,
7, 27–32)
The Hardy Few on Leaner Pastures
Authors: Goldberg Elkhonon
Published: July 2002

An acquaintance of mine once said that “scientists
are like cattle. They graze the surface and move on to
greener pastures.” The author of this jaded verdict
is himself a successful scientist and a master grazer,
so he should know. Hemispheric specialization used to be
among the more inviting pastures, but no longer is. Most
young researchers tend to search for other pastures.
Green accounting: from theory to practice
Authors: VINCENT JEFFREY R.
Published: July 2002

A decade has passed since Wasting Assets, a study of Indonesia by Robert
Repetto and colleagues at the World Resources Institute, drew widespread
attention to the potential divergence between gross and net measures of
national income. This was by no means the first ‘green accounting’ study.
Martin Weitzman, John Hartwick, and Partha Dasgupta and Geoffrey
Heal had all conducted seminal theoretical work in the 1970s. But the
World Resources Institute study demonstrated that data were adequate
even in a developing country to estimate adjustments for the depletion of
some important forms of natural capital and that the adjustments could
be large relative to conventional, gross measures of national product and
investment. The adjusted, net measures suggested that a substantial
portion of Indonesia's rapid economic growth during the 1970s and
1980s was simply the unsustainable ‘cashing in’ of the country's natural
wealth.
Valuation of biodiversity within a north–south trade model
Authors: CABO FRANCISCO
Published: July 2002

Under a General Equilibrium model of International Trade, industrialized countries export capital intensive goods, while developing countries export natural resource intensive goods. Biodiversity is viewed as the number of species conserved while producing these goods. Higher conservation increases demand, but lowers goods supply. Consumers value biodiversity as the weighted sum of all the different species. If producers of both goods conserve more species, the South's terms of trade will rise in relation to the North's. Furthermore, we believe that a switch in consumer preferences, to a more homogeneous valuation of the species, is likely. This change would drop the South's terms of trade. Therefore, under these circumstances, this region is facing a risk. In conserving additional species, the South would be better off, both because its terms of trade increases and because the risk associated with a switch in preferences decreases.
A history of sampling
Authors: DAVIES HUGH
Published: July 2002

Since the mid-1980s commercial digital samplers have become widespread. The idea of musical instruments which have no sounds of their own is, however, much older, not just in the form of analogue samplers like the Mellotron, but in ancient myths and legends from China and elsewhere. This history of both digital and analogue samplers relates the latter to the early musique concrète of Pierre Schaeffer and others, and also describes a variety of one-off systems devised by composers and performers.
Sound in space
Authors: MYATT TONY
Published: July 2002

There has been an extraordinary amount of interest in sound spatialisation
in recent years. The volume of work in this area has pushed many
international organisations to feature sound spatialisation as a theme for
conferences and publications, and Organised Sound is probably
overdue in having a thematic issue based upon aspects of sound in
space. This issue of Organised Sound contains many different views
of space. We have included articles about spatialisation techniques, our
understanding of sound spatialisation, composition, performance and spaces
inside music as well as the spaces and environments where music can exist,
including virtual spaces.
Adapting Multisystemic Therapy to Serve Youth
Presenting Psychiatric Emergencies: Two Case Studies
Authors: Rowland Melisa D. , Henggeler Scott W. , Gordon Anita M. , Pickrel Susan G. , Cunningham Phillippe B. , Edwards James E.
Published: July 2002

Multisystemic therapy (MST) is a highly individualised family- and home-based treatment that has successfully served as a clinically effective and
cost-effective alternative to out-of-home placements (e.g., incarceration,
psychiatric hospitalisation) for youth presenting serious clinical problems.
MST clinical procedures are reviewed and two extensive case summaries
are used to explicate the MST intervention process for treating serious
antisocial behaviour and modifications in that process needed to safely
and effectively serve youth presenting psychiatric emergencies.
The orthography and phonology of the Ormulum
Authors: Anderson John , Britton Derek
Published: July 2002

This paper investigates all aspects of the orthography of the Ormulum in relation to the phonology of the late twelfth-century south Lincolnshire dialect which Orm's spelling system was designed to reflect. We show that Orm's adaptations of what he found in existing orthographic systems provided a set of graphic symbols that was fully capable of representing phonological contrasts in the vocabulary of the dialect and which thus in many respects resembled the inventory that an analysis on phonemic principles might provide. However, Orm's system has more orthographic symbols than an analysis of distinctive oppositions in speech would have required. All of these additions are in some measure attributable to following precedent. In this aspect of his spelling system, as in his innovations, nearly all of which also have parallels within the English orthographic tradition, we discern a spelling reformer who, in due consideration of transparency of the system as perceived by the reader, took pains to depart as little as possible from the familiar.
COMPARISON OF BOOTSTRAP CONFIDENCE INTERVALS FOR IMPULSE RESPONSES OF
GERMAN MONETARY SYSTEMS
Authors: Benkwitz Alexander , Lütkepohl Helmut , Wolters Jürgen
Published: July 2002

It is argued that standard impulse response analysis based on vector autoregressive models has a number of
shortcomings. Although the impulse responses are estimated
quantities, measures for sampling variability such as
confidence intervals sometimes are not provided. If
confidence intervals are given, they often are based on
bootstrap methods with dubious theoretical properties. These
problems are illustrated using two German monetary systems.
Proposals are made for improving current practice. Special
emphasis is placed on systems with cointegrated
variables.
Strengthening the global trade architecture for development: the post Doha agenda
Authors: HOEKMAN BERNARD
Published: July 2002

Despite recurring rounds of trade liberalization under GATT/WTO
auspices, complemented by unilateral reforms, many developing countries have not
been able to integrate into the world economy. This paper argues that, from the
perspective of the poorest countries, a multi-pronged strategy is required to
strengthen the global trading system and that much of the agenda must be addressed
outside the WTO. The most important contribution the WTO can make from a
development perspective is to improve market access conditions – for goods and
services – and ensure that trade rules are useful to developing countries. Enhancing
trade capacity requires concerted action outside the WTO (‘aid for trade’) as well
as unilateral actions by both industrialized and developing countries to reduce anti-trade biases.
Seed bank classification of the Strandveld Succulent Karoo, South Africa
Authors: Villiers A.J. De , Rooyen M.W. Van , Theron G.K.
Published: July 2002

Laboratory characteristics of seeds of 37 species (41 seed types) from the Strandveld Succulent Karoo were used to predict seed bank types according to a modified key of ). Five seed bank strategies were recognized for this vegetation type, i.e. two with transient and three with persistent seed bank strategies. Of the 37 species investigated, 32% (all perennial species) had transient seed bank strategies, while 68% had persistent seed bank strategies. Seed dispersal of these 37 species was mainly anemochorous, although antitelechoric elements such as myxospermy, hygrochasy, heterodiaspory and synaptospermy were found among these species. The seed bank alone will not be sufficient to restore the vegetation of damaged land in the Strandveld Succulent Karoo, since many of the dominant species in the vegetation do not produce persistent seed banks. Many of these species may, however, be dispersed by wind into revegetation areas from surrounding vegetation. Topsoil replacement, seeding and transplanting of selected species will be essential for the successful revegetation of mined areas in this part of Namaqualand.
In vivo chromatin remodeling by yeast ISWI homologs Isw1p and Isw2p
Authors: Kent Nicholas A. , Karabetsou Nickoletta , Politis Panagiotis K. , Mellor Jane
Published: July 2002

Isw1p and Isw2p are budding yeast homologs of the DrosophilaISWI chromatin-remodeling ATPase. Using indirect-end-label and chromatin immunoprecipitation analysis, we show both independent and cooperative Isw1p- and Isw2p-mediated positioning of short nucleosome arrays in gene-regulatory elements at a variety of transcription units in vivo. We present evidence that both yeast ISWI complexes regulate developmental responses to starvation and that for Isw2p, recruitment by different DNA-binding proteins controls meiosis and haploid invasive growth.
The yeast Xrs2 complex functions in S phase checkpoint regulation
Authors: D'Amours Damien , Jackson Stephen P.
Published: July 2002

The Nbs1 complex is an evolutionarily conserved multisubunit nuclease composed of the Mre11, Rad50, and Nbs1 proteins. Hypomorphic mutations in the NBS1 or MRE11 genes in humans result in conditions characterized by DNA damage sensitivity, cell cycle checkpoint deficiency, and high cancer incidence. The equivalent complex in the yeast Saccharomyces cerevisiae (Xrs2p complex) has been implicated in DNA double-strand break repair and in telomere length regulation. Here, we find that xrs2Δ,mre11Δ, and rad50Δ mutants are markedly defective in the initiation of the intra-S phase checkpoint in response to DNA damage. Furthermore, the absence of a functional Xrs2p complex leads to sensitivity to deoxynucleotide depletion and to an inability to efficiently slow down cell cycle progression in response to hydroxyurea. The checkpoint appears to require the nuclease activity of Mre11p and its defect is associated with the abrogation of the Tel1p/Mec1p signaling pathway. Notably, DNA damage induces phosphorylation of both Xrs2p and Mre11p in a Tel1p-dependent manner. These results indicate that the Tel1p/ATM signaling pathway is conserved from yeast to humans and suggest that the Xrs2p/Nbs1 complexes act as signal modifiers.
naked cuticle targets dishevelled to antagonize Wnt signal transduction
Authors: Rousset Raphaël , Mack Judith A. , Wharton Keith A. , Axelrod Jeffrey D. , Cadigan Ken M. , Fish Matthew P. , Nusse Roel , Scott Matthew P.
Published: July 2002

In Drosophila embryos the protein Naked cuticle (Nkd) limits the effects of the Wnt signal Wingless (Wg) during early segmentation.nkd loss of function results in segment polarity defects and embryonic death, but how nkd affects Wnt signaling is unknown. Using ectopic expression, we find that Nkd affects, in a cell-autonomous manner, a transduction step between the Wnt signaling components Dishevelled (Dsh) and Zeste-white 3 kinase (Zw3). Zw3 is essential for repressing Wg target-gene transcription in the absence of a Wg signal, and the role of Wg is to relieve this inhibition. Our double-mutant analysis shows that, in contrast to Zw3, Nkd acts when the Wg pathway is active to restrain signal transduction. Yeast two hybrid and in vitro experiments indicate that Nkd directly binds to the basic-PDZ region of Dsh. Specially timed Nkd overexpression is capable of abolishing Dsh function in a distinct signaling pathway that controls planar-cell polarity. Our results suggest that Nkd acts directly through Dsh to limit Wg activity and thus determines how efficiently Wnt signals stabilize Armadillo (Arm)/β-catenin and activate downstream genes.
Biosynthesis of Isoprenoids via Mevalonate in Archaea: The Lost Pathway
Authors: Smit Arian , Mushegian Arcady
Published: July 2002

Isoprenoid compounds are ubiquitous in living species and diverse in biological function. Isoprenoid side chains of the membrane lipids are biochemical markers distinguishing archaea from the rest of living forms. The mevalonate pathway of isoprenoid biosynthesis has been defined completely in yeast, while the alternative, deoxy-D-xylulose phosphate synthase pathway is found in many bacteria. In archaea, some enzymes of the mevalonate pathway are found, but the orthologs of three yeast proteins, accounting for the route from phosphomevalonate to geranyl pyrophosphate, are missing, as are the enzymes from the alternative pathway. To understand the evolution of isoprenoid biosynthesis, as well as the mechanism of lipid biosynthesis in archaea, sequence motifs in the known enzymes of the two pathways of isoprenoid biosynthesis were analyzed. New sequence relationships were detected, including similarities between diphosphomevalonate decarboxylase and kinases of the galactokinase superfamily, between the metazoan phosphomevalonate kinase and the nucleoside monophosphate kinase superfamily, and between isopentenyl pyrophosphate isomerases and MutT pyrophosphohydrolases. Based on these findings, orphan members of the galactokinase, nucleoside monophosphate kinase, and pyrophosphohydrolase families in archaeal genomes were evaluated as candidate enzymes for the three missing steps. Alternative methods of finding these missing links were explored, including physical linkage of open reading frames and patterns of ortholog distribution in different species. Combining these approaches resulted in the generation of a short list of 13 candidate genes for the three missing functions in archaea, whose participation in isoprenoid biosynthesis is amenable to biochemical and genetic investigation.
Maze Navigation by Honeybees: Learning Path Regularity
Authors: Zhang Shaowu , Mizutani Akiko , Srinivasan Mandyam V.
Published: July 2002

We investigated the ability of honeybees to learn mazes of four types: constant-turn mazes, in which the appropriate turn is always in the same direction in each decision chamber; zig-zag mazes, in which the appropriate turn is alternately left and right in successive decision chambers; irregular mazes, in which there is no readily apparent pattern to the turns; and variable irregular mazes, in which the bees were trained to learn several irregular mazes simultaneously. The bees were able to learn to navigate all four types of maze. Performance was best in the constant-turn mazes, somewhat poorer in the zig-zag mazes, poorer still in the irregular mazes, and poorest in the variable irregular mazes. These results demonstrate that bees do not navigate such mazes simply by memorizing the entire sequence of appropriate turns. Rather, performance in the various configurations depends on the existence of regularity in the structure of the maze and on the ease with which this regularity is recognized and learned.
Changes in the Expression and the Enzymic Properties of the 20S Proteasome in Sugar-Starved Maize Roots. Evidence for an in Vivo Oxidation of the Proteasome
Authors: Basset Gilles , Raymond Philippe , Malek Lada , Brouquisse Renaud
Published: July 2002

The 20S proteasome (multicatalytic proteinase) was purified from maize (Zea mays L. cv DEA 1992) roots through a five-step procedure. After biochemical characterization, it was shown to be similar to most eukaryotic proteasomes. We investigated the involvement of the 20S proteasome in the response to carbon starvation in excised maize root tips. Using polyclonal antibodies, we showed that the amount of proteasome increased in 24-h-carbon-starved root tips compared with freshly excised tips, whereas the mRNA levels of α3 and β6 subunits of 20S proteasome decreased. Moreover, in carbon-starved tissues, chymotrypsin-like and caseinolytic activities of the 20S proteasome were found to increase, whereas trypsin-like activities decreased. The measurement of specific activities and kinetic parameters of 20S proteasome purified from 24-h-starved root tips suggested that it was subjected to posttranslational modifications. Using dinitrophenylhydrazine, a carbonyl-specific reagent, we observed an increase in carbonyl residues in 20S proteasome purified from starved root tips. This means that 20S proteasome was oxidized during starvation treatment. Moreover, an in vitro mild oxidative treatment of 20S proteasome from non-starved material resulted in the activation of chymotrypsin-like, peptidyl-glutamyl-peptide hydrolase and caseinolytic-specific activities and in the inhibition of trypsin-like specific activities, similar to that observed for proteasome from starved root tips. Our results provide the first evidence, to our knowledge, for an in vivo carbonylation of the 20S proteasome. They suggest that sugar deprivation induces an oxidative stress, and that oxidized 20S proteasome could be associated to the degradation of oxidatively damaged proteins in carbon starvation situations.
Developmental Stage-Specific and Nitrate-Independent Regulation of Nitrate Reductase Gene Expression in Rapeseed
Authors: Fukuoka H. , Ogawa T. , Minami H. , Yano H. , Ohkawa Y.
Published: July 2002

cDNA clones for two isogenes of nitrate reductase (NR) have been isolated from rapeseed (Brassica napus L.) androgenetic haploid embryos induced by microspore culture. NR mRNA accumulation can be detected by northern hybridization at 14 d after culture initiation when embryos develop to the heart/torpedo-shaped stage. Whole-mount in situ hybridization experiments demonstrate that the mRNA accumulation is developmental stage specific. In addition, even when cultured in media containing no nitrate, embryos accumulated NR mRNA to almost the same level as the control. This indicates the unique regulation of NR in embryogenesis in which NR mRNA transcription is activated in a developmental stage-specific manner that is independent of nitrate induction. In zygotic embryogenesis, a stage-specific accumulation of NR mRNA was also observed. By contrast, the obvious effect of nitrate on NR expression that has been reported in many plant species was also confirmed in rapeseed leaf. Quantitative combined reverse transcription-poly-merase chain reaction analysis suggests that the flexible and variable regulation of NR expression, which is organ specific, nitrogen metabolite specific, and developmental stage specific, is caused principally by regulation of one major structural gene.
Mutualistic Fungal Endophytes Express a Proteinase that Is Homologous to Proteases Suspected to Be Important in Fungal Pathogenicity
Authors: Reddy P. V. , Lam C. K. , Belanger F. C.
Published: July 2002

Many cultivated and wild grass species are hosts to mutualistic fungal endophytes. These associations are ecologically and agronomically significant, yet little is known regarding the physiological aspects of the interaction. In the Poa ampla/Acremonium typhinum interaction, a fungal serine proteinase, At1, is surprisingly abundant and may constitute 1 to 2% of the total leaf-sheath protein. Sequence analysis of cDNA and genomic clones indicates that proteinase At1 is a member of the eukaryotic subtilisin-like protease family. It is homologous to proteases suspected to be virulence factors in fungal pathogens of insects, nematodes, and other fungi. Gel blot analysis of RNA extracted from infected leaf-sheath tissue indicates that the proteinase At1 transcript level is extremely high. RNA gel blots and immunoblots of purified enzymes indicate that similar proteinases are produced by Epichloe festucae and Acremonium lolii, the fungal endophytes infecting Festuca rubra subsp. rubra and Lolium perenne, respectively. Fungal expression of proteinase At1-like enzymes may be a general feature of endophyte infection.
Phosphorylation of Serine-15 of Maize Leaf Sucrose Synthase (Occurrence in Vivo and Possible Regulatory Significance)
Authors: Huber S. C. , Huber J. L. , Liao P. C. , Gage D. A. , McMichael Jr R. W. , Chourey P. S. , Hannah L. C. , Koch K.
Published: July 2002

Experiments were conducted to determine whether sucrose synthase (SuSy) was phosphorylated in the elongation zone of maize (Zea mays L.) leaves. The approximately 90-kD subunit of SuSy was 32P-labeled on seryl residue(s) when excised shoots were fed [32P]orthophosphate. Both isoforms of SuSy (the SS1 and SS2 proteins) were phosphorylated in vivo, and tryptic peptide-mapping analysis suggested a single, similar phosphorylation site in both proteins. A combination of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and automated Edman sequencing analysis unequivocally identified the phosphorylation site in the maize SS2 protein as serine-15. This site was phosphorylated in vitro by endogenous protein kinase(s) in a strictly Ca2+-dependent manner. A synthetic peptide, based on the phosphorylation site sequence, was used to identify and partially purify an endogenous Ca2+-dependent protein kinase(s) from the maize leaf elongation zone and expanding spinach leaves. Phosphorylation of SuSy in vitro selectively activates the cleavage reaction by increasing the apparent affinity of the enzyme for sucrose and UDP, suggesting that phosphorylation may be of regulatory significance. Conservation of the phosphorylation site, and the sequences surrounding it, among plant species suggests that phosphorylation of SuSy may be widespread, if not universal, in plants.
Differential Expression of Soybean Cysteine Proteinase Inhibitor Genes during Development and in Response to Wounding and Methyl Jasmonate
Authors: Botella M. A. , Xu Y. , Prabha T. N. , Zhao Y. , Narasimhan M. L. , Wilson K. A. , Nielsen S. S. , Bressan R. A. , Hasegawa P. M.
Published: July 2002

Three cysteine proteinase inhibitor cDNA clones (pL1, pR1, and pN2) have been isolated from a soybean (Glycine max L. Merr.) embryo library. The proteins encoded by the clones are between 60 and 70% identical and contain the consensus QxVxG motif and W residue in the appropriate spatial context for interaction with the cysteine proteinase papain. L1, R1, and N2 mRNAs were differentially expressed in different organs of plants (juvenile and mature) and seedlings, although N2 mRNA was constitutive only in flowers. R1 and N2 transcripts were induced by wounding or methyl jasmonate (M-JA) treatment in local and systemic leaves coincident with increased papain inhibitory activity, indicating a role for R1 and N2 in plant defense. The L1 transcript was constitutively expressed in leaves and was induced slightly by M-JA treatment in roots. Unlike the chymotrypsin/trypsin proteinase inhibitor II gene (H. Pena-Cortes, J. Fisahn, L. Willmitzer [1995] Proc Natl Acad Sci USA 92: 4106–4113), expression of the soybean genes was only marginally induced by abscisic acid and only in certain tissues. Norbornadiene, a competitive inhibitor of ethylene binding, abolished the wounding or M-JA induction of R1 and N2 mRNAs but not the accumulation of the wound-inducible vspA transcript. Presumably, ethylene binding to its receptor is involved in the wound inducibility of R1 and N2 but not vspA mRNAs. Bacterial recombinant L1 and R1 proteins, expressed as glutathione S-transferase fusion proteins, exhibited substantial inhibitory activities against vicilin peptidohydrolase, the major thiol endopeptidase in mung bean seedlings. Recombinant R1 protein had much greater cysteine proteinase inhibitor activity than recombinant L1 protein, consistent with the wound inducibility of the R1 gene and its presumed role in plant defense.
Immunopurification and Characterization of a 40-kD 1-Aminocyclopropane-1-Carboxylic Acid N-Malonyltransferase from Mung Bean Seedling Hypocotyls
Authors: Chick WSH. , Leung P. C.
Published: July 2002

1-Aminocylopropane-1-carboxylic acid (ACC) N-malonyltransferase catalyzes the transfer of the malonyl group from malonyl coenzyme A to ACC to form malonyl ACC. Using partially purified ACC N-malonyltransferase from the hypocotyls of mung bean (Vigna radiata) seedlings, we produced two mouse monoclonal antibodies (1H5 and 2G3) to this enzyme. These antibodies bind to sites other than the active site of the enzyme because monoclonal antibody-bound ACC N-malonyltransferase still exhibits full catalytic activity. A monoclonal antibody column was constructed using 1H5 and protein G Sepharose. The ACC N-malonyltransferase purified from this monoclonal antibody column has a molecular mass of 40 kD, which is different from that reported previously. The enzyme has a higher electrophoretic mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the absence of the reducing agent dithiothreitol. The optimum temperature of this 40-kD ACC N-malonyltransferase is 45[deg]C and the apparent Kms for ACC and malonyl coenzyme A are 66.7 and 40 [mu]M, respectively.