bluuebunny/crossref_metadata_2025 huggingface dataset:
Housing for elderly people
Authors: Tinker Anthea
Published: July 2002

Despite the growing recognition of the importance of housing for the health and well-being of elderly people there has been less research on the topic than on health or personal social services. Moreover, until recently, what research there

was tended to concentrate on specialized, rather than mainstream, forms of housing. This review looks at research on the meaning of home; the kind of housing elderly people live in; tenure; specialized and nonspecialized housing; some issues to do with an assessment of needs; and at links between services. The very important related topic of moving in old age is not covered because this was the focus of a recent review in this journal. However, it is relevant to note that research shows that

many people move into specialized housing against their will and wish that they could have remained at home. This review also excludes consideration of other related topics such as household composition, affordability, the contribution of technology such as alarms and ‘smart’ houses, and problems of specific groups, such as those who are homeless.
Aging homeostasis
Authors: O'Neill PA
Published: July 2002

Homeostasis is the ability of a living organism to control its internal environment despite fluctuations in the external environment. Claude Bernard proposed the concept of 'milieu interieur'. The hypothesis rests on the belief that cells need a precisely defined local environment in which to function optimally. The maintenance of the micro-environment is dependent on integration of the systems of the organism (body), including behaviour, to protect the cell(s) from external stressors. When the environment changes, the body needs to sense the alteration, then set in motion mechanisms which mitigate the change and restore the previous balance. If it fails to do this, the organism will ultimately die as systems fail.
Death in England and Wales
Authors: Cartwright Ann
Published: July 2002

Dying is the one common and certain event in life but it is a difficult process to study. Official statistics give information about the point of death; studies covering random samples of deaths are inevitably retrospective and based on the accounts of those who knew the person who died; other studies are selective and generally focused on people dying from cancer, so they include a relatively small proportion of old people. Yet, in developed countries, deaths are concentrated among older people. In England and Wales in 1994 83.6% of all deaths were of people aged 65 or over; 59.0% were 75 or more.
Has the White-necked Picathartes Picathartes gymnocephala still a chance in Lamto, Ivory Coast?
Authors: Salewski Volker , Göken Frank , Korb Judith , Schmidt Silke
Published: July 2002

A rocky area in Lamto, Ivory Coast, which is partly surrounded by plantations, was searched for nests of the White-necked Picathartes Picathartes gymnocephala. A total of 34 nests was found of which 10 were only remnants, 12 old and 12 rather new. One nest contained two chicks. It is suggested that ecotourism might be a suitable means to help to protect the species, but care has to be taken to avoid any further disturbance.
Estimated population size of the Island Scrub-Jay Aphelocoma insularis
Authors: Kelsey Rodd , Collins Charles T.
Published: July 2002

As an island endemic, the Island Scrub-Jay's Aphelocoma insularis population status and conservation are of concern. In addition, because the Island Scrub-Jay is easily observed, it is an ideal candidate for monitoring the effects of management efforts on Santa Cruz Island, California. We used estimates of territory size in several different habitats occupied by the Island Scrub-Jay and the total area of these habitats on the island to develop an empirical estimate of the population size for this species. Our most conservative, and we feel most realistic, estimate for the Island Scrub-Jay breeding population is 7,000 individuals and for the non-breeding population 5,500 individuals, yielding a total population estimate of 12,500. Even though conservative, this estimate is larger than earlier estimates of 4,000 to 6,000 individuals. Even so, our data suggest no reason exists for immediate concern regarding the population viability of the Island Scrub-Jay and they provide a baseline for future estimates and comparisons. Most importantly, this population estimate can be used to monitor the influence on the Island Scrub-Jay of future island management efforts, especially regarding exotic tree species and feral pigs.
HOW UNIVERSAL ARE UNIVERSAL rDNA PRIMERS? A CAUTIONARY NOTE FOR PLANT SYSTEMATISTS AND PHYLOGENETICISTS
Authors: MÖLLER M.
Published: July 2002

Phylogenetic relationships are frequently inferred from rDNA ITS sequences obtained employing universal primers. Whereas in most cases phylogenetic topologies inferred from ITS data make good biological sense, caution has to be used when a number of taxa vary greatly in PCR yield. The phylogenetic implications of such a scenario are discussed.
The pathophysiology and treatment of ovarian hyperstimulation syndrome
Authors: McClure N , McElhinney B
Published: July 2002

The ovarian hyperstimulation syndrome (OHSS) remains one of the enigmas of reproductive medicine. We all fear its development in our patients and we all have “pet” policies for its prevention and treatment. Despite this, its incidence has not changed significantly in the last 20 years with the severe form still occurring in 0.3–5.0% of cycles. Its pathogenesis clearly has a physiological basis but it would appear to be compounded by the body's homeostatic response to the changes produced by the syndrome.
The Global Ethics of Latex Gloves: Reflections on Natural
Resource Use in Healthcare
Authors: Pierce Christina Kerby Jessica , Kerby Christina
Published: July 2002

A quick tour through an average U.S. hospital gives
pause to anyone with even a rudimentary concern for environmental
issues. To a careful observer, the typical U.S. hospital
presents an array of challenges to the health of ecosystems.
For example, hospitals consume vast quantities of natural
resources. The most obvious of these are fossil fuels,
which form the basic building blocks of the industrialized
medical care industry. Aside from the worry that our healthcare
systems are technologically and functionally dependent
upon nonrenewable, relatively scarce, and politically volatile
resources, our heavy reliance on fossil fuels has important
ill effects, including unfavorable health outcomes for
humans. For example, the combustion of fossil fuels is
the driving force behind global warming, which will likely
result in increasing heat-related mortality and morbidity
and may contribute to the spread and resurgence of infectious
diseases around the world. Also, the combustion of coal
and oil releases pollutants such as sulfur oxides, nitrogen
oxides, and ground-level ozone that contribute to various
respiratory ailments. In addition to being energy intensive,
the modern hospital uses a great deal of water, wood, paper,
metals, minerals, plastics, chemicals, food, and land.
The emergence of urban environmental history
Authors: Platt Harold L.
Published: July 2002

The three books under review represent the origins and promise of a relatively new field of study, urban environmental history. Joel Tarr's collection of previously published essays retraces the intellectual odyssey of its single most important pioneer. Concerned about contemporary pollution problems, he has spent a quarter of a century exploring the frontiers of scholarship on the relationship between cities and their technologies. In contrast, monographs by R. Bruce Stephenson and Andrew Hurley are typical of current trends to build on this foundation, enriching and broadening its parameters from a wide variety of perspectives. Here the insights of town planning and social history illuminate case studies of St Petersburg, Florida, and Gary, Indiana, respectively. Other recent works draw heavily upon the sciences, especially medicine and public health. Reversing decades of academic fragmentation – knowing more and more about less and less – the study of the urban environment is encouraging creative applications of cross-disciplinary and comparative approaches.
Fetal biophysical profile: a critical appraisal
Authors: Manning Frank A
Published: July 2002

In medicine, in general and fetal medicine in particular, the conceptual development and emerging application of a new diagnostic modality is fuelled firstly by a general recognition of the increasing relative importance of a particular clinical problem and then by critical examination of the body of scientific observation, often disparate in origin, that provides the key insights into the pathophysiology, manifestation and natural history of the disease process. So it is with the evolution of the fetal biophysical profile score. In general terms, until the 1950's the major goal of obstetric care was the prevention of maternal mortality and morbidity. As the result of a host of clinical advances including improved anaesthesia and surgical techniques and availability of blood and blood products, antibiotics and specific other drugs (oxytocin, anticonvulsants, antihypertensives, insulin etc.) maternal mortality declined to the low rates of the present day. Consequently, the focus of obstetric care shifted to the recognition and prevention of death or damage affecting the other patient in the obstetric dyad: the fetus. The first methods for evaluation of antepartum fetal health care were based on measurements of biochemical variables in the maternal compartment (e.g. oestriol, placental lactogen, alkaline phosphatase and oxytocinase).
Human immunodeficiency virus infection in pregnancy
Authors: Newell Marie-Louise , Thorne Claire
Published: July 2002

The human immunodeficiency virus (HIV) is a retrovirus which causes immune suppression mainly through depletion and destruction of CD4 lymphocytes. This results in increased susceptibility to opportunistic infections which in turn leads to acquired immune deficiency syndrome (AIDS). Since HIV (HIV-1) was first identified in 1983, the infection has spread across the world and has developed into arguably the most important and far-reaching pandemic of this century. HIV infection can be acquired through sexual contact, blood or blood products (including contaminated injecting equipment) and vertically from mother to child. Heterosexual acquisition is the dominant route among women, although in some settings injecting drug use (IDU) can also be an important source. In 1985, HIV-2 was isolated in a study of Senegalese women and subsequently found to be prevalent in West Africa and in areas of emigration from West Africa. HIV-2 is less transmissable and pathogenic than HIV-1 and this review is restricted to HIV-1 infection.
Periventricular leucomalacia in preterm neonates. Obstetrical factors
Authors: Senat MV , De Keersmaecker B , Ville Y
Published: July 2002

Cerebral Palsy (CP) describes a group of permanent non progressive but often changing neurological impairement syndromes as assessed at 3 and 5 years of age. The term includes serious motor disorders including spastic diplegia (Little syndrome), hemiplegia and quadriplegia associated with neuropsychological seizures and cognitive impairment due to permanent damage to the immature brain. Fifty percent of CP cases are premature neonates and 25% are very severely premature. There is a significant correlation between CP and brain lesions in the neonatal period among which periventricular leukomalacia (PVL) is the most common.
Calmodulin, gametes and fertilisation
Authors: Courtot Anne-Marie , Pesty Arlette , Lefèvre Brigitte
Published: July 2002

The role of calmodulin in fertilisation
events was examined in a zona-free mouse system by using a selective calmodulin inhibitor,
calmidazolium (1 μM). The effects of this antagonist were studied either on the ooplasmic calcium
oscillations induced by fertilisation by using the Ca2+ indicator, fluo-3/AM, or on
pronucleus formation 4 h later by using the nucleic acid stain, Syto-15. When the calmidazolium
treatment was applied to one or the other gamete before insemination, the fertilisation process was
affected only when spermatozoa were treated: most of the oocytes were partially fertilised as
demonstrated by the profile of Ca2+ oscillations and the presence of polar bodies with no
typical male and female pronuclei. When the treatment was applied during insemination, more than half
the oocytes were unfertilised and only a few were partially fertilised. These results demonstrate
that: (1) the calmodulin-dependent events taking place in spermatozoa before insemination appear
essential at least for regular Ca2+ oscillations and for pronucleus formation; (2) the
inhibition of calmodulin by calmidazolium applied to metaphase II oocytes before insemination has no
major impact on their fertilising ability; and (3) at the time of gamete fusion calmodulin, either
from the oocyte or from the spermatozoon, is essential for fertilisation to occur.
HAGAR IN CHRISTIAN BRITAIN: GRACE AGUILAR’S “THE WANDERERS”
Authors: Harris Daniel A.
Published: July 2002

But he who was of the bondwoman was born after the flesh; but he of the free woman was by promise. Which things are an allegory: for these are the two covenants; the one from the mount Sinai, which gendereth to bondage, which is Hagar. For this Hagar is mount Sinai in Arabia, and answereth to Jerusalem which now is, and is in bondage with her children. But Jerusalem which is above is free, which is the mother of us all. . . . Now we, brethren, as Isaac was, are the children of promise.

— St. Paul, Epistle to the Galatians

These Ishmaels and Hagars of mankind . . .

— Longfellow, “The Jewish Cemetery at Newport,” 1852

GIVEN PAUL’S TORTUOUS, divisive rhetoric, the Jew is always the proto-Christian, deprived of actual historical identity and development. For Christianity, founding itself on usurpation, cannot dispense with the Abrahamic covenant or the sacrifice of Isaac (to Jews, the akedah, binding) that prefigures the martyrdom of Jesus. Because Christianity begins by absorbing Hebraic characters as patterns, it must represent real Jews by a second displacement, as non-Jews: “These Ishmaels and Hagars of mankind.” In Christian eyes, the Jew is twice dispossessed — once by metamorphosis into the potentially free Christian, and again by disguise as a creature of bondage.
Comparison of atmospheric transport calculations over complex terrain using a mobile profiling system and rawinsondes
Authors: Cox Robert M , Cogan James , Sontowski John , Dougherty Catherine M , Fry Richard N , Smith Thomas J
Published: July 2002

A comparison of atmospheric transport and dispersion calculations over complex terrain was investigated using a mobile profiling system (MPS) versus standard meteorological balloons. Meteorological and sulfur hexafluoride (SF6) concentration data were collected and used to evaluate the performance of a transport and diffusion model coupled with a mass consistency wind field model. Meteorological data were collected throughout April 1995, and parts of August 1995. Both meteorological and concentration data were measured in December 1995. Once the models were validated, the comparison of performance with different upper‐air data were accomplished. The models used included the SCIPUFF (Second‐order Closure Integrated Puff) transport and diffusion model and the MINERVE mass consistency wind model. Evaluation of the models was focused primarily on their effectiveness as a short‐term (one to four hours) predictive tool. These studies showed how the combination of weather and transport models could be used to help direct emergency response following a hazardous material release. The models were used in tandem to direct the deployment of mobile sensors intended to intercept and measure tracer clouds. The MINERVE model was validated for the specific terrain of interest using April 1995 data. The capability of SCIPUFF driven by realistic three‐dimensional wind fields generated by MINERVE is demonstrated using data collected in December 1995. Copyright © 2000 Royal Meteorological Society
Cold frontal structure derived from radar wind profilers
Authors: Browning K A , Jerrett D , Nash J , Oakley T , Roberts N M
Published: July 2002

Colocated UHF and VHF wind profiler radars have been operated during the passage of a sharp cold front. The results demonstrate the utility of the profilers, in conjunction with a conceptual model, for identifying and quantifying many of the features commonly associated with such fronts: low‐level and upper‐level jets, and rearward‐sloping warm‐conveyor‐belt flow with underlying rear‐inflow. The UHF radar detected much of the transverse circulation and also the vertical distribution of precipitation, including a possible region of evaporation associated with the dry rear‐inflow jet. The VHF radar, in addition to extending the velocity measurements above the level of the precipitation, mapped the tropopause and, in particular, identified a tropopause fold, the position of which corresponded to the origin of the rear‐inflow jet detected by both profilers. Copyright © 1998 Royal Meteorological Society
TREATMENT OF INTRUSIVE RUMINATIONS ABOUT MATHEMATICS
Authors: Albert Idit , Hayward Peter
Published: July 2002

The unusual case of a young mathematics student is described. While studying and at other times he was troubled by intrusive thoughts about the logical foundations of mathematics. A treatment package involving the use of thought stopping, emotional processing and training in study skills is described and some ideas about the treatment of intrusive thought are considered.
Considering the Relationship Between Biological Aging and Cognitive Aging
Authors: Saxton Judith
Published: July 2002

The psychological and neuropsychological changes of
aging and dementia have been a topic of study for decades,
if not centuries. It is only more recently, however, that
technological changes have allowed the biological processes
triggering the changes of aging to be uncovered. The overlap
between these two sciences, namely, the relationship between
cognitive aging and the study of biological aging, is an
emerging area of research. The study of aging, however,
is confounded by the close association between aging and
the development of particular diseases. Older people are
far more likely than young people to suffer from multiple
illnesses. Furthermore, older people are far more vulnerable
to specific types of diseases such as heart disease, cancer,
and dementia. The relationship between the onset of the
aging process and the development of dementing disorders
such as Alzheimer's disease is of particular interest.
Verbal working memory in HIV-seropositive drug users
Authors: FARINPOUR ROXANNA , MARTIN EILEEN M. , SEIDENBERG MICHAEL , PITRAK DAVID L. , PURSELL KENNETH J. , MULLANE KATHLEEN M. , NOVAK RICHARD M. , HARROW MARTIN
Published: July 2002

Recent evidence suggests that HIV-seropositive drug
users are impaired on tasks of visuospatial working
memory compared with drug users seronegative for HIV. In
the current study we evaluated the performance of 30 HIV-seropositive
male drug users and 30 risk-matched seronegative controls
on two measures of verbal working memory, the Listening
Span and the verbal Self Ordered Pointing Task. Impaired
working memory performance was significantly more common
among HIV-seropositive persons compared to controls, with
the highest incidence of deficit among symptomatic participants.
These findings indicate that working memory deficits in
persons with HIV are not domain-specific and can be demonstrated
reliably in drug users. (JINS, 2000, 6,
548–555.)
Lost in Translation
Authors: Mendez Mario F.
Published: July 2002

On the surface, reviewing a dictionary seems like
a relatively straightforward task. The book is an extensive
compilation of terms used in psychology and psychiatry.
The dictionary provides a comprehensive listing of the
English–Spanish translation equivalents that can
be useful to psychologists and psychiatrists working in
increasingly bilingual environments. This book could facilitate
professional communications across the English–Spanish
divide.
The effect of development on the climate sensitivity of agriculture
Authors: MENDELSOHN ROBERT , DINAR ARIEL , SANGHI APURVA
Published: July 2002

This paper examines whether a country's stage of development affects its climate sensitivity. The paper begins with a model of agriculture that shows that the effect of development on climate sensitivity is ambiguous, depending on the substitution between capital and climate. To resolve this issue, the climate sensitivity of agriculture in the United States, Brazil, and India is measured using a Ricardian approach. Relying on both intertemporal as well as cross-country comparisons, the empirical analysis suggests that increasing development reduces climate sensitivity.
Categorising complex dynamic sounds
Authors: MIRANDA EDUARDO RECK , CORREA JAMES , WRIGHT JOE
Published: July 2002

Chaosynth is a cellular automata-based granular synthesis system whose
capabilities for producing unusual complex dynamic sounds are
limitless. However, due to its newness and flexibility, potential users
have found it very hard to explore its possibilities as there is no clear
referential framework to hold on to when designing sounds. Standard software
synthesis systems take this framework for granted by adopting a taxonomy for
synthesis instruments that has been inherited from the acoustic musical
instruments tradition, i.e. woodwind, brass, string, percussion, etc. Sadly,
the most interesting synthesised sounds that these systems can produce are
simply referred to as effects. This scheme clearly does not meet the demands
of more innovative software synthesizers. In order to alleviate this
problem, we propose an alternative taxonomy for Chaosynth timbres. The paper
begins with a brief introduction to the basic functioning of Chaosynth. It
then presents our proposed taxonomy and ends with concluding comments. A
number of examples are provided on this volume's Organised Sound CD.
Assessing Children's Peer Relationships
Authors: Pepler Debra J. , Craig Wendy M.
Published: July 2002

Peers have both positive and negative influences on children; therefore,

considerable attention has focused on assessing peer relationships and

friendships through childhood and adolescence. The present article
provides an overview of the main methods of assessing peer relationships.

The adaptive nature of children's peer relations has been assessed
through
four main methodologies: (1) asking the children themselves about
elements of peer relations and friendships; (2) asking children about their

perceptions of others within the peer group; (3) asking adults (i.e. parents

and teachers) about the peer relations skills of children in their care;
and
(4) directly observing children during interactions with peers. Each of

these approaches is described, with attention to relative strengths and

weaknesses and their suitability for assessing peer relations in early

childhood, middle childhood, and adolescence.
Family Therapy and Beyond:
Where is the Milan Systemic
Approach Today?
Authors: Campbell David
Published: July 2002

This paper reviews the current position of the Milan Approach in the family
therapy field. Over the past 20 years this approach has made a major
contribution to the development of family therapy theory and practice in
the U.K. However, the ideas have been modified in order to fit different
client groups in a range of settings; until today, the Milan, or Post-Milan
approach is an amalgam of the original concepts and new techniques. This
paper describes the development of this approach and highlights the
following topics as central to current thinking: language, power, narrative,
family resilience, externalising, focusing on change, and solution focused
approaches. Several techniques of the Post-Milan approach are
demonstrated in a discussion of one case treated by the author.
TIME-SERIES MODEL WITH PERIODIC STOCHASTIC REGIME SWITCHING
Authors: Bac Catherine , Chevet Jean-MicheI , Ghysels Eric
Published: July 2002

This paper provides a historical chronology of economic activity in 16th- and 17th-century France that is based on wheat price series in Paris and Toulouse. A stochastic regime-switching model enables us to benchmark eras and summarize the salient features of a development difficult to appraise in all its complexity. A new class of Markov regime-switching time-series models is introduced to allow for nontrivial interdependencies between different types of cycles that make the economy grow at an unsteady rate. With a predominantly agricultural cycle, we uncover a strongly periodic Markov switching scheme for recorded wheat prices from the grain markets of Paris and Toulouse. Besides the periodic nature of the Markov chain, we also study whether a common factor determined the state of the economy in Paris and Toulouse or whether each series moved independently.
SIMPLE MODEL OF ASYMMETRICAL
BUSINESS CYCLES: INTERACTIVE DYNAMICS OF A LARGE
NUMBER OF AGENTS WITH DISCRETE CHOICES
Authors: Aoki Masanao
Published: July 2002

A (jump) Markov process (generalized birth-and-death process) is used to model
interactions of a large number of agents subject to field-type externalities. Transition
rates are (nonlinear) functions of the composition of the population of agents classified
by the choices they make. The model state randomly moves from one equilibrium
to another, and
exhibits asymmetrical oscillations (business cycles). It is shown that
the processes can have several locally stable equilibria, depending on the degree of
uncertainty associated with consequences of alternative choices.
There is a positive probability of transition between any pair of such
basins of attraction, and mean first-passage times between equilibria can be
different when different pairs of basins
are calculated.
Mixed languages: a functional–communicative approach
Authors: Matras Yaron
Published: July 2002

It has been suggested that the structural composition of mixed languages and the linguistic processes through which they emerge are to some extent predictable, and that they therefore constitute a language “type” (e.g. Bakker and Mous, 1994b; Bakker and Muysken, 1995). This view is challenged here. Instead, it is argued that the compartmentalisation of structures observed in mixed languages (i.e. the fact that certain structural categories are derived from one “parent” language, others from another) is the result of the cumulative effect of different contact mechanisms. These mechanisms are defined in terms of the cognitive and communicative motivations that lead speakers to model certain functions of language on an alternative linguistic system; each mechanism will typically affect particular functional categories. Four relevant processes are identified: lexical re-orientation, selective replication, convergence, and categorial fusion. Different combinations of processes will render different outcomes, hence the diversity of mixed languages as regards their structure, function, and development.
Topoisomerase IV, alone, unknots DNA in E. coli
Authors: Deibler Richard W. , Rahmati Sonia , Zechiedrich E. Lynn
Published: July 2002

Knotted DNA has potentially devastating effects on cells. By using two site-specific recombination systems, we tied all biologically significant simple DNA knots in Escherichia coli. When topoisomerase IV activity was blocked, either with a drug or in a temperature-sensitive mutant, the knotted recombination intermediates accumulated whether or not gyrase was active. In contrast to its decatenation activity, which is strongly affected by DNA supercoiling, topoisomerase IV unknotted DNA independently of supercoiling. This differential supercoiling effect held true regardless of the relative sizes of the catenanes and knots. Finally, topoisomerase IV unknotted DNA equally well when DNA replication was blocked with hydroxyurea. We conclude that topoisomerase IV, not gyrase, unknots DNA and that it is able to access DNA in the cell freely. With these results, it is now possible to assign completely the topological roles of the topoisomerases in E. coli. It is clear that the topoisomerases in the cell have distinct and nonoverlapping roles. Consequently, our results suggest limitations in assigning a physiological function to a protein based upon sequence similarity or even upon in vitro biochemical activity.
Contact Call-Driven Zenk Protein Induction and Habituation in Telencephalic Auditory Pathways in the Budgerigar (Melopsittacus Undulatus): Implications For Understanding Vocal Learning Processes
Authors: Brauth Steven , Liang Wenru , Roberts Todd F. , Scott Lindsey L. , Quinlan Elizabeth M.
Published: July 2002

Expression of the immediate early gene protein Zenk (zif 268, egr-1, NGF1A,Krox24) was induced in forebrain auditory nuclei in a vocal learning parrot species, the budgerigar (Melopsittacus undulatus), when the subjects either listened to playbacks of an unfamiliar contact call or to a contact call with which they had been familiarized previously. Auditory nuclei included the Field L complex (L1, L2a, and L3), the neostriatum intermedium pars ventrolateralis (NIVL), the neostriatum adjacent to caudal nucleus basalis (peri-basalis or pBas), an area in the frontal lateral neostriatum (NFl), the supracentral nucleus of the lateral neostriatum (NLs), and the ventromedial hyperstriatum ventrale (HVvm). The latter three nuclei are main sources of auditory input to the vocal system. Two patterns of nuclear staining were induced by contact call stimulation—staining throughout cell nuclei, which was exhibited by at least some neurons in all areas examined except L2a and perinucleolar staining, which was the only kind of staining exhibited in field L2a. The different patterns of Zenk staining indicate that auditory stimulation may regulate the Zenk-dependent transcription of different subsets of genes in different auditory nuclei. The numbers of neurons expressing Zenk staining increased from seven- to 43-fold over control levels when the birds listened to a repeating unfamiliar call. Familiarization of the subjects with the call stimulus, through repeated playbacks, greatly reduced the induction of Zenk expression to the call when it was presented again after an intervening 24-h interval. To determine if neurons exhibiting contact call-driven Zenk expression project to the vocal control system, call stimulation was coupled with dextran amines pathway tracing. The results indicated that tracer injections in the vocal nucleus HVo (oval nucleus of the hyperstriatum ventrale), in fields lateral to HVo and in NLs labeled many Zenk-positive neurons in HVvm, NFl, and NLs. These results support the idea that, in these neurons, egr-1 couples auditory stimulation to the synthesis of proteins involved in either the storing of new perceptual engrams for vocal learning or the processing of novel and/or meaningful acoustic stimuli related to vocal learning or the context in which it occurs.
Phospholipase A2 Activity Triggers the Wound-Activated Chemical Defense in the Diatom Thalassiosira rotula
Authors: Pohnert Georg
Published: July 2002

The activation of oxylipin-based chemical defense in the diatom Thalassiosira rotula is initiated by phospholipases that act immediately after cell damage. This lipase activity is responsible for the preferential release of free mono- and polyunsaturated fatty acids. Among these, eicosatetraenoic- and eicosapentaenoic acid are further converted by lipoxygenases to reactive defensive metabolites such as the antiproliferative α,β,γ,δ-unsaturated aldehydes 2,4-decadienal and 2,4,7-decatrienal. We show that mainly saturated free fatty acids are present in the intact diatom T. rotula, whereas the amount of free polyunsaturated eicosanoids is drastically increased in the first minutes after wounding. Using fluorescent probes, the main enzyme activity responsible for initiation of the aldehyde-generating lipase/lipoxygenase/hydroperoxide lyase cascade was characterized as a phospholipase A2. All enzymes involved in this specific defensive reaction are active in seawater over several minutes. Thus, the mechanism allows the unicellular algae to overcome restrictions arising out of potential dilution of defensive metabolites. Only upon predation are high local concentrations of aldehydes formed in the vicinity of the herbivores, whereas in times of low stress, cellular resources can be invested in the formation of eicosanoid-rich phospholipids. In contrast to higher plants, which use lipases acting on galactolipids to release C18 fatty acids for production of leaf-volatile aldehydes, diatoms rely on phospholipids and the transformation of C20 fatty acids to form 2,4-decadienal and 2,4,7-decatrienal as an activated defense.
Temporal and Spatial Distribution of Ferredoxin Isoproteins in Tomato Fruit
Authors: Aoki K. , Wada K.
Published: July 2002

Five ferredoxin (Fd) isoproteins (FdA, FdB, FdC, FdD, and FdE) were isolated from tomato (Lycopersicon esculentum cv Momotaro) fruit. These isoproteins showed differential temporal and spatial accumulation patterns. FdA and FdC were present in leaves, FdE was present in roots, and FdB and FdD were fruit-specific. During fruit growth, the relative abundance of FdA decreased and that of FdE increased. The FdE/FdA ratio was higher in the inner tissues of the fruit than in the outer tissue, and it was correlated with starch accumulation. In dark-grown fruit the contents of FdA, FdB, and FdC, as well as chlorophyll, decreased remarkably relative to their light-grown counterparts; however, the contents of FdE and starch did not change significantly. Under in vitro conditions FdE showed higher cytochrome c reduction activity than FdA and FdB. These results, together with their N-terminal sequences, indicate that both photosynthetic- and heterotrophic- type Fd isoproteins are present in tomato fruit.
Multiple Phytochromes Are Involved in Red-Light-Induced Enhancement of First-Positive Phototropism in Arabidopsis thaliana
Authors: Janoudi Ak. , Gordon W. R. , Wagner D. , Quail P. , Poff K. L.
Published: July 2002

The amplitude of phototropic curvature to blue light is enhanced by a prior exposure of seedlings to red light. This enhancement is mediated by phytochrome. Fluence-response relationships have been constructed for red-light-induced enhancement in the phytochrome A (phyA) null mutant, the phytochrome B- (phyB) deficient mutant, and in two transgenic lines of Arabidopsis thaliana that overexpress either phyA or phyB. These fluence-response relationships demonstrate the existence of two responses in enhancement, a response in the very-low-to-low-fluence range, and a response in the high-fluence range. Only the response in the high-fluence range is present in the phyA null mutant. In contrast, the phyB-deficient mutant is indistinguishable from the wild-type parent in red-light responsiveness. These data indicate that phyA is necessary for the very-low-to-low but not the high-fluence response, and that phyB is not necessary for either response range. Based on these results, the high-fluence response, if controlled by a single phytochrome, must be controlled by a phytochrome other than phyA or phyB. Overexpression of phyA has a negative effect and overexpression of phyB has an enhancing effect in the high-fluence range. These results suggest that overexpression of either phytochrome perturbs the function of the endogenous photoreceptor system in an unpredictable fashion.
Aluminum Induces Oxidative Stress Genes in Arabidopsis thaliana1
Authors: Richards Keith D. , Schott Eric J. , Sharma Yogesh K. , Davis Keith R. , Gardner Richard C.
Published: July 2002

Changes in gene expression induced by toxic levels of Al were characterized to investigate the nature of Al stress. A cDNA library was constructed from Arabidopsis thaliana seedlings treated with Al for 2 h. We identified five cDNA clones that showed a transient induction of their mRNA levels, four cDNA clones that showed a longer induction period, and two down-regulated genes. Expression of the four long-term-induced genes remained at elevated levels for at least 48 h. The genes encoded peroxidase, glutathione-S-transferase, blue copper-binding protein, and a protein homologous to the reticuline:oxygen oxidoreductase enzyme. Three of these genes are known to be induced by oxidative stresses and the fourth is induced by pathogen treatment. Another oxidative stress gene, superoxide dismutase, and a gene for Bowman-Birk protease inhibitor were also induced by Al in A. thaliana. These results suggested that Al treatment of Arabidopsis induces oxidative stress. In confirmation of this hypothesis, three of four genes induced by Al stress in A. thaliana were also shown to be induced by ozone. Our results demonstrate that oxidative stress is an important component of the plant's reaction to toxic levels of Al.
Transcriptional and Posttranscriptional Control of mRNA fromlrtA, a Light-Repressed Transcript inSynechococcus sp. PCC 70021
Authors: Samartzidou Hrissi , Widger William R.
Published: July 2002

Transcription regulation and transcript stability of a light-repressed transcript,lrtA, from the cyanobacteriumSynechococcus sp. PCC 7002 were studied using ribonuclease protection assays. The transcript for lrtA was not detected in continuously illuminated cells, yet transcript levels increased when cells were placed in the dark. A lag of 20 to 30 min was seen in the accumulation of this transcript after the cells were placed in the dark. Transcript synthesis continued in the dark for 3 h and the transcript levels remained elevated for at least 7 h. The addition of 10 μm rifampicin to illuminated cells before dark adaptation inhibited the transcription oflrtA in the dark. Upon the addition of rifampicin to 3-h dark-adapted cells, lrtA transcript levels remained constant for 30 min and persisted for 3 h. A 3-h half-life was estimated in the dark, whereas a 4-min half-life was observed in the light. Extensive secondary structure was predicted for this transcript within the 5′ untranslated region, which is also present in the 5′ untranslated region of lrtA from a different cyanobacterium, Synechocystis sp. PCC 6803. Evidence suggests that lrtA transcript stability is not the result of differences in ribonuclease activity from dark to light. Small amounts of lrtA transcript were detected in illuminated cells upon the addition of 25 μg mL−1chloramphenicol. The addition of chloramphenicol to dark-adapted cells before illumination allowed detection of the lrtA transcript for longer times in the light relative to controls without chloramphenicol. These results suggest that lrtA mRNA processing in the light is different from that in the dark and that protein synthesis is required for light repression of thelrtA transcript.
The Role of Gibberellin, Abscisic Acid, and Sucrose in the Regulation of Potato Tuber Formation in Vitro1
Authors: Xu Xin , van Lammeren André A.M. , Vermeer Evert , Vreugdenhil Dick
Published: July 2002

The effects of plant hormones and sucrose (Suc) on potato (Solanum tuberosum L.) tuberization were studied using in vitro cultured single-node cuttings. Tuber-inducing (high Suc) and -noninducing (low Suc or high Suc plus gibberellin [GA]) media were tested. Tuberization frequencies, tuber widths, and stolon lengths were measured during successive stages of development. Endogenous GAs and abscisic acid (ABA) were identified and quantified by high-performance liquid chromatography and gas chromatography-mass spectrometry. Exogenous GA4/7 promoted stolon elongation and inhibited tuber formation, whereas exogenous ABA stimulated tuberization and reduced stolon length. Indoleacetic acid-containing media severely inhibited elongation of stolons and smaller sessile tubers were formed. Exogenous cytokinins did not affect stolon elongation and tuber formation. Endogenous GA1 level was high during stolon elongation and decreased when stolon tips started to swell under inducing conditions, whereas it remained high under noninducing conditions. GA1 levels were negatively correlated with Suc concentration in the medium. We conclude that GA1 is likely to be the active GA during tuber formation. Endogenous ABA levels decreased during stolon and tuber development, and ABA levels were similar under inducing and noninducing conditions. Our results indicate that GA is a dominant regulator in tuber formation: ABA stimulates tuberization by counteracting GA, and Suc regulates tuber formation by influencing GA levels.
Overexpression of ATP Sulfurylase in Indian Mustard Leads to Increased Selenate Uptake, Reduction, and Tolerance1
Authors: Pilon-Smits Elizabeth A.H. , Hwang Seongbin , Mel Lytle C. , Zhu Yongliang , Tai Jenny C. , Bravo Rogelio C. , Chen Yichang , Leustek Tom , Terry Norman
Published: July 2002

In earlier studies, the assimilation of selenate by plants appeared to be limited by its reduction, a step that is thought to be mediated by ATP sulfurylase. Here, the Arabidopsis APS1 gene, encoding a plastidic ATP sulfurylase, was constitutively overexpressed in Indian mustard (Brassica juncea). Compared with that in untransformed plants, the ATP sulfurylase activity was 2- to 2.5-fold higher in shoots and roots of transgenic seedlings, and 1.5- to 2-fold higher in shoots but not roots of selenate-supplied mature ATP-sulfurylase-overexpressing (APS) plants. The APS plants showed increased selenate reduction: x-ray absorption spectroscopy showed that root and shoot tissues of mature APS plants contained mostly organic Se (possibly selenomethionine), whereas wild-type plants accumulated selenate. The APS plants were not able to reduce selenate when shoots were removed immediately before selenate was supplied. In addition, Se accumulation in APS plants was 2- to 3-fold higher in shoots and 1.5-fold higher in roots compared with wild-type plants, and Se tolerance was higher in both seedlings and mature APS plants. These studies show that ATP sulfurylase not only mediates selenate reduction in plants, but is also rate limiting for selenate uptake and assimilation.
Purification of the Trehalase GMTRE1 from Soybean Nodules and Cloning of Its cDNA. GMTRE1 Is Expressed at a Low Level in Multiple Tissues1
Authors: Aeschbacher Roger A. , Müller Joachim , Boller Thomas , Wiemken Andres
Published: July 2002

Trehalose (α-d-glucopyranosyl-1,1-α-d-glucopyranoside), a disaccharide widespread among microbes and lower invertebrates, is generally believed to be nonexistent in higher plants. However, the recent discovery of Arabidopsis genes whose products are involved in trehalose synthesis has renewed interest in the possibility of a function of trehalose in higher plants. We previously showed that trehalase, the enzyme that degrades trehalose, is present in nodules of soybean (Glycine max [L.] Merr.), and we characterized the enzyme as an apoplastic glycoprotein. Here we describe the purification of this trehalase to homogeneity and the cloning of a full-length cDNA encoding this enzyme, named GMTRE1(G. maxtrehalase1). The amino acid sequence derived from the open reading frame of GMTRE1 shows strong homology to known trehalases from bacteria, fungi, and animals. GMTRE1 is a single-copy gene and is expressed at a low but constant level in many tissues.
Overexpression of Plastidic Protoporphyrinogen IX Oxidase Leads to Resistance to the Diphenyl-Ether Herbicide Acifluorfen
Authors: Lermontova Inna , Grimm Bernhard
Published: July 2002

The use of herbicides to control undesirable vegetation has become a universal practice. For the broad application of herbicides the risk of damage to crop plants has to be limited. We introduced a gene into the genome of tobacco (Nicotiana tabacum) plants encoding the plastid-located protoporphyrinogen oxidase of Arabidopsis, the last enzyme of the common tetrapyrrole biosynthetic pathway, under the control of the cauliflower mosaic virus 35S promoter. The transformants were screened for low protoporphyrin IX accumulation upon treatment with the diphenyl ether-type herbicide acifluorfen. Leaf disc incubation and foliar spraying with acifluorfen indicated the lower susceptibility of the transformants against the herbicide. The resistance to acifluorfen is conferred by overexpression of the plastidic isoform of protoporphyrinogen oxidase. The in vitro activity of this enzyme extracted from plastids of selected transgenic lines was at least five times higher than the control activity. Herbicide treatment that is normally inhibitory to protoporphyrinogen IX oxidase did not significantly impair the catalytic reaction in transgenic plants and, therefore, did not cause photodynamic damage in leaves. Therefore, overproduction of protoporphyrinogen oxidase neutralizes the herbicidal action, prevents the accumulation of the substrate protoporphyrinogen IX, and consequently abolishes the light-dependent phytotoxicity of acifluorfen.
Positional Cloning in Arabidopsis. Why It Feels Good to Have a Genome Initiative Working for You
Authors: Lukowitz Wolfgang , Gillmor C. Stewart , Scheible Wolf-Rüdiger
Published: July 2002

Positional (or map-based) cloning techniques are widely used to identify the protein products of genes defined by mutation. In Arabidopsis the information generated by the Genome Initiative is giving this approach a decisive boost. A wealth of sequence polymorphisms and molecular markers is now available and can be exploited for fine mapping with technically simple and robust polymerase chain reaction-based methods. As a result it has become possible to complete positional cloning projects in a short time and with relatively little effort.
Long-Term Growth of Ginkgo with CO2 Enrichment Increases Leaf Ice Nucleation Temperatures and Limits Recovery of the Photosynthetic System from Freezing
Authors: Terry Andrew C. , Quick W. Paul , Beerling David J.
Published: July 2002

The importance of subzero temperature interactions with elevated CO2 on plant carbon metabolism has received rather little attention, despite their likely role in influencing future vegetation productivity and dynamics. Here we focused on the critical issues of CO2-enrichment effects on leaf-freezing temperatures, subsequent membrane damage, and recovery of the photosynthetic system. We show that growth in elevated CO2 (70 Pa) results in a substantial and significant (P < 0.01) increase (up to 4°C) in the ice nucleation temperature of leaves of Maidenhair tree (Ginkgo biloba), which was observed consistently throughout the 1999 growing season relative to their ambient CO2 (35 Pa) counterparts. We suggest that increased sensitivity of leaves to ice damage after growth in elevated CO2 provides an explanation for increased photoinhibition observed in the field early and late in the growing season when low nighttime temperatures are experienced. This new mechanism is proposed in addition to the earlier postulated explanation for this phenomenon involving a reduction in the rate of triose-P utilization owing to a decrease in the rate of carbohydrate export from the leaf.