bluuebunny/crossref_metadata_2025 huggingface dataset:
Seed mass versus seedling performance in Scots pine: a maternally dependent trait
Authors: CASTRO JORGE
Published: March 2003

It is generally accepted that larger seeds give rise to seedlings with better performance. On the other hand, the size that a seed reaches is genetically determined by at least two different traits ; the genetic variability of the developing embryo and the genetic variability of the maternal plant. Thus, the relative contributions of these two traits affect seedling performance by influencing seed size. In this paper, I investigate the effect of seed size on seedling performance in the Scots pine (Pinus sylvestris). From eight maternal plants, 50 seeds were planted in each of two soil types (800 seeds in total), and seedling performance was monitored for 1 yr. Seed mass proved to be highly constant within maternal plants. Soil type influenced emergence and survival; however, the effect of soil type differed depending on maternal origin. Seed mass was positively correlated with seedling emergence, although this relationship was not found for seedling survival or date of emergence. The initial growth of the shoot was also positively correlated with seed mass. However, after one growing season, seed mass had no effect on seedling performance, which depended exclusively on maternal origin. Nevertheless, the mean mass of seeds produced by plants was positively correlated with mean values of growth parameters. Thus, first‐year seedling performance seems to be a maternal trait indirectly associated with seed size.
Effects of salinity and convective rhizome ventilation on amino acid and carbohydrate patterns of Phragmites australis populations in the Neusiedler See region of Austria and Hungary
Authors: ROLLETSCHEK HARDY , HARTZENDORF THOMAS
Published: March 2003

Parameters of convective ventilation and also the content and composition of free amino acids and free carbohydrates in roots, basal culm internodes and leaves were investigated in five stands of Phragmites australis that were subjected to different growth conditions and salinity levels. Shoot length, stem diameter and productivity decreased with increasing salinity. These morphometric variations in turn affected parameters of convective ventilation and amino acid patterns. Phragmites populations growing at the highest salinity levels possessed the lowest rhizome conductivities, which was probably caused by their more pronounced xeromorphic growth. High counterpressures of the rhizome system and low stem diameters were limiting factors for convective flows. The Phragmites stand with lowest flow rate and ventilation efficiency had the highest percentage of alanine, serine and γ‐aminobutyric acid (55% of total free amino acids) in its roots, indicating hypoxic stress in basal plant parts. Increasing salinity was connected with significantly higher fractions of glutamine (in basal culm internodes), glutamate (in roots) and proline (in both) as well as slightly increasing osmolality of plant sap. However, total contents of free amino acids and carbohydrates were low, and not related to either salinity level or osmolality of plant sap. This suggests that they might not have an important, direct role as an osmolyte in P. australis. Stand‐specific variations in amino acid and carbohydrate patterns of leaves were negligible. Ratios of amino acids to carbohydrate were positively related to potential N supply. It is concluded that (1) salinity affects convective rhizome ventilation by varying the reed morphometry, and (2) the pattern of free amino acids responds characteristically to conditions of salinity and hypoxic growth.
Companion cells in the secondary phloem of Indian dicotyledonous species: a quantitative study
Authors: CHAVAN R. R. , BRAGGINS J. E. , HARRIS P. J.
Published: March 2003

Companion cells in the secondary phloem of 125 Indian dicotyledonous species belonging to 43 families were examined by light microscopy. Four types of companion cell were identified: E‐, S‐ and L‐types which were equal in length, shorter, or longer, respectively, than the associated sieve tube element; and R‐type, in which two or more companion cells in a vertical row were associated with the sieve tube element. The commonest was the E‐type and the rarest was the L‐type. E‐type companion cells were most frequently found associated with short sieve tube elements (50–250 μm) which had a high frequency of simple sieve plates, considered phylogenetically advanced. R‐type companion cells were most frequently associated with long sieve tube elements (>400 μm) with a high frequency of compound sieve plates, considered phylogenetically the least advanced. A strong positive correlation was found between the average number of companion cells associated with a sieve tube element and the lengths of the sieve tube elements. There was also a strong negative correlation between the average number of companion cells associated with a sieve tube element and companion cell lengths.
Ecological, morphological and allozymic differentiation between diploid and tetraploid knapweeds (Centaurea jacea) from a contact zone in the Belgian Ardennes
Authors: HARDY O. J. , VANDERHOEVEN S. , DE LOOSE M. , MEERTS P.
Published: March 2003

In the northeastern part of Belgium, the Centaurea jacea complex shows extensive morphological variation and is
represented by a diploid (2n = 22) and a tetraploid (2n = 44) cytotype. Polysomic inheritance of allozyme markers in the tetraploids, suggesting autopolyploidy, is here demonstrated for the first time. In order to test whether the two cytotypes occupy distinct habitats and possess different gene pools, patterns of allozymic and morphological variation were investigated in relation to ploidy level and site characteristics in 26 populations from the Belgian Ardennes. The two cytotypes showed a parapatric distribution, the diploids occurring at higher elevations (mostly above 500 m) than the tetraploids (mostly below 500 m). Three mixed populations were found near the contact zone of the two cytotypes. Within the mixed populations no triploid plant and no evidence for gene flow between cytotypes were found, despite widely overlapping flowering periods. The two cytotypes can be distinguished on the basis of morphological traits and enzymatic gene pools. The congruence of morphological and allozymic variation with chromosome numbers suggests a secondary contact between the two cytotypes with limited gene flow between them. The origin and persistence of the parapatric distribution are discussed.
Role of proline and leaf expansion rate in the recovery of stressed white clover leaves with increased phosphorus concentration
Authors: SINGH DHANANJAY K. , SALE PETER W. G. , PALLAGHY CHARLES K. , SINGH VIJAYA
Published: March 2003

Osmotic adjustment (OA) and increased cell‐wall extensibility required for expansive leaf growth are well defined components of adaptation to water stress in dry soil, which might interact with soil phosphorus (P) concentration and defoliation frequency for intensively grazed white clover in legume‐based pastures. Experiments were conducted with frequently and infrequently defoliated mini‐swards of white clover growing in dry soil with low and high P concentrations. The higher yielding high‐P plants were able to dry the soil to greater soil water suctions; their leaves had lower water potential values, yet they showed fewer water stress symptoms and underwent a more complete recovery from the water stress symptoms on rewatering, than the low‐P plants. High‐ P plants had greater OA, proline concentration and leaf expansion rate. On the other hand, low‐P plants showed an increased osmotic concentration when there was no change in the total solute content per unit of leaf d. wt, indicating more loss of water from the leaf tissue. The key measures that appeared to be directly associated with plant recovery over a short period following water stress were increased proline concentration and leaf expansion rate, probably resulting from increased cell‐wall extensibility rather than increased production of cells for the high‐P plants.
Effects of tree size and temperature on relative growth rate and its components of Fagus sylvatica seedlings exposed to two partial pressures of atmospheric [CO2]
Authors: BRUHN DAN , LEVERENZ JERRY W. , SAXE HENRIK
Published: March 2003

Growth responses of two provenances of European beech (Fagus sylvatica) were studied. The seedlings were
grown in closed‐top chambers at four temperature regimes (−2.9 °C below ambient, ambient, +2.3 °C and +4.8 °C
above ambient) in combination with two CO2 partial pressures (40 Pa and 74 Pa). Growth was followed by making
destructive harvests c. every 25 d from germination in early June to senescence in late September. Allocation
patterns were significantly affected by the temperature regimes. However, changes in dry matter allocation and
morphology associated with the different treatments at a given time were mostly a result of differences in tree size.
Temperature regimes only had a significant effect on the relative growth rate, RGR, at the beginning of the
experiment. In contrast to temperature, high [CO2] increased RGR throughout the experiment when compared
with plants of equal size. As the trees increased in size net assimilation rate, NAR, decreased but the effect of [CO2]
on both NAR and RGR had a tendency to increase. Increases in NAR caused by elevated [CO2] were partly
counteracted by reductions in the leaf area ratio, LAR. Reductions in LAR were caused by concomitant reductions
in specific leaf area, SLA, whereas the level of [CO2] did not significantly affect leaf weight ratio, LWR, nor other
dry weight ratios. The interactions between temperature and [CO2] are highly dependent on whether they are
expressed as instantaneous values for plants at a common age or instantaneous values at a common size (and
thereby extracting the effects of ontogenetic drift). When comparing instantaneous values at common sizes, the
positive effect of [CO2] on RGR increased with plant size in every temperature regime. This also occurred in every
temperature regime when comparing plants of equal age but the response to [CO2] was less. The effect of [CO2]
on RGR was dependent on growth temperature. The positive effects of elevated [CO2] on RGR were less than the
positive effect on photosynthesis. The two provenances did not differ significantly in the response of RGR to [CO2] which is in agreement with measurements of photosynthesis.
The bryophyte Physcomitrella patens replicates extrachromosomal transgenic elements
Authors: ASHTON NEIL W. , CHAMPAGNE CONNIE E. M. , WEILER TRACEY , VERKOCZY LAURENT K.
Published: March 2003

Physcomitrella patens, recently renamed Aphanoregma patens, has been transformed with the plasmid, pBI426. On selective medium approx. 30% of regenerants expressed the transformed phenotype transiently (transients). The remaining 70% (transformants) retained their transformed phenotype (GUS‐positive and resistant to G418) indefinitely when subcultured repeatedly on selective medium. However, most lost this phenotype after one or two passages through nonselective medium (unstable transformants). Approximately 0.2% of transformants retained their transformed phenotype after numerous passages through nonselective medium (stable transformants). Using PCR methodology, it has been shown that loss of the transformed phenotype by unstable transformants is invariably accompanied by disappearance of the transgenic DNA. Southern blot analysis data argue strongly that unstable transformants cultured under selective conditions contain unintegrated pBI426 as circular concatenates consisting of 3–40 copies of the plasmid. Under selective conditions, it appears that replication and/or partitioning of these extrachromosomal concatemers might be growth rate‐limiting. This is the first report of a transgenic, autonomously replicating extrachromosomal element in a photosynthetic plant. A single copy of pBI426 has been inserted into the moss genome in each of three stable transformants analysed.
The trans‐tissue pathway and chemical fate of 14C photoassimilate in carrot taproot
Authors: KOROLEV ANDREY V. , DERI TOMOS A. , FARRAR JOHN F.
Published: March 2003

Axial and radial transport and the accumulation of photoassimilates in carrot taproot were studied using 14C
labelling and autoradiography. Axial transport of the 14C labelled assimilates inside the taproot was rapid and
occurred mainly in the young phloem found in rows radiating from the cambium. The radial transport of the
assimilate inward (to cambium, xylem zone and pith) and outward (to phloem zone and periderm) from the
conducting phloem was an order of magnitude slower than the longitudinal transport and was probably mainly
diffusive. The cambial zone of the taproot presented a partial barrier in the inward path of the assimilate to the
xylem zone. We suggest that this is due to the cambium comprising a strong sink for the assimilate on the basis
that our previous work has shown that it contains very low concentrations of free sucrose. By contrast, a high
accumulation of nonsoluble 14C was found in the cambium region in good agreement with the active growth of
this zone. Autoradiography following the feeding of 14C labelled sugars to excised sections of taproot indicated that only a ring of cells at and/or just within the cambium take up sugars from the apoplast. This indicates that radial movement in the phloem and pith must be symplastic. An apoplastic step between phloem and xylem is possible. The rapid uptake of sugars from the apoplast at this point might represent a mechanism for keeping photoassimilates away from the transpiration stream and re‐location back to the leaves.
Bioaccumulation of lead by the lichen Acarospora smaragdula from smelter emissions
Authors: PURVIS O. W. , WILLIAMSON B. J. , BARTOK K. , ZOLTANI N.
Published: March 2003

Accumulation of lead in the crustose lichen Acarospora smaragdula sensu lato is reported in the vicinity of an ore‐ processing plant where it is subjected to acidification and metal particulate fallout. A combination of light microscopy, X‐ray element mapping, field emission scanning electron microscopy (FESEM) and other analytical techniques identifies Pb accumulation within specific fungal tissues derived from smelter particles (PM10s). No Pb was detected within the photobiont layer. Our studies suggest that Pb is highly mobile under the prevailing acidic conditions, and is fixed within the lichen cortex and melanized apothecia. Lead is also accumulated within the medulla and at the rock–lichen interface where it may precipitate as amorphous botryoidal encrustations on medullary hyphae and iron‐rich particles. Modern FESEMs and microprobes enable analysis of minute quantities of material, and are important tools in understanding the fate of metals within lichens necessary to develop their use as predictive and sensitive bioindicators of aerial particulate contaminants. We suggest that crustose lichens, hitherto largely ignored in metal pollution studies, may be useful bioindicators of aerial particulate contaminants in polluted areas where macrolichens are absent.
Air pollution: forest health and passive sampling
Authors: Chappelka Arthur H.
Published: March 2003

32nd Annual Air Pollution Workshop

Auburn University in Auburn, AL, USA, April 2000

Air pollution has profound effects on agriculture, forests and natural ecosystems. The first Air Pollution Workshop was held over 30 years ago, and the most vital issues have always been highlighted within this forum. This year, forest health and passive sampling of air pollutants were two key areas of interest.
Root tissue structure is linked to ecological strategies of grasses
Authors: WAHL STEFAN , RYSER PETER
Published: March 2003

The present study investigated to what extent there is a link between root tissue structure and ecological strategies of plant species; such a link is known for leaf tissue structure. We investigated experimentally root tissue mass density, root diameter and several characteristics of root anatomy in the axile roots of 19 perennial grass species from different habitats and related these parameters to the ecological behaviour of the species. Root characteristics were assessed in new roots produced by mature plants grown under standardized conditions. The ecological behaviour was characterized in terms of relative growth rate (RGR), plant height at maturity and ecological indicator values for nutrients, light and tolerance to mowing according to Ellenberg. We found a striking dichotomy between root anatomical characteristics associated with interspecific variation in RGR and those associated with variation in plant height. RGR correlated with anatomical characteristics that contribute to root robustness, whereas plant height correlated with characteristics associated with axile root hydraulic conductance. RGR correlated negatively with tissue mass density (TMDr) in roots. Interspecific variation in TMDr was explained by the proportion of stele in the cross‐sectional area (CSA) of the axile root and the proportion of cell wall in the CSA of the stele. For a given root diameter, slow growing species had smaller, albeit more numerous, xylem vessels, indicating a higher resistance to cavitation and protection against embolisms. Plant height correlated positively with root CSA, total xylem CSA and mean xylem vessel CSA, indicating a need for a high transport capacity in roots of species that attain a large size at maturity. TMDr correlated positively with dry matter content in leaves. The results emphasize the close relationship between tissue structure and growth characteristics at the whole‐plant level.
Mobilization of fructan reserves and changes in enzyme activities in wheat stems correlate with water stress during kernel filling
Authors: WARDLAW I. F. , WILLENBRINK J.
Published: March 2003

Triticum aestivum (wheat) plants grown at a day∶night temperature of 18∶13 °C from anthesis were held as well watered controls, or subject to either a mild (large pot volume) or a more severe (small pot volume) water stress by withholding water from the time of anthesis. Extracts from the peduncle (enclosed by the flag leaf sheath) and the penultimate internode were prepared to determine the activities of fructan exohydrolase and acid invertase and to assess the level of hexose sugars, sucrose and fructans. Measurements were made of ear and individual grain weights and stem fresh weight and dry weight. Plant water relations at the time of each sampling were determined as the flag leaf water potential and the water content of individual organs. Water stress resulted in a shorter duration of kernel filling, smaller kernels at maturity and an earlier loss of stem weight. There was an increase in stem fructose and a fall in fructan level that preceded the loss of dry matter associated with water stress. Coincident with the early fall in fructan content under water stress there was a rise in both fructan exohydrolase and acid invertase in the internodes of stressed plants. This correlation suggests that the conversion of fructans to fructose might have resulted from enzyme induction associated with water stress, but as this conversion occurs before the major export of reserves from the stem it might be only indirectly related to changes in the demand for reserves.
Longevity of mycorrhizal roots depends on branching order and nutrient availability
Authors: Majdi Hooshang , Damm Eva , Nylund Jan‐Erik
Published: March 2003

The effects are reported of branching order and nitrogen fertilization on the longevity of mycorrhizal short roots at a Norway spruce (Picea abies) stand in south‐west Sweden.

A 4‐yr qualitative analysis was made, using minirhizotrons, of the emergence frequency and life span of individual mycorrhizal roots of three root orders (unbranched, main axes of branched and side branches of branched short roots, orders 1, 2 and 3, respectively).

Longevity of mycorrhizal roots varied with branching order and soil depth, being greatest in unbranched (order 1) roots and those at the greatest soil depth (40–85 cm). Nitrogen addition decreased the proportion of higher mycorrhizal root orders (a fivefold reduction in order 3 compared with controls), while increasing the median longevity. Seasonal effects were recorded; mycorrhizal roots produced in spring and summer remained unsuberized during the winter.

Mycorrhizal root longevity depends on the branching order of mycorrhizal roots and nitrogen addition decreases branching density while increasing longevity. The survival of mycorrhizal roots, which remain vital and unsuberized over winter, enhances water and nutrient efficiency of Norway spruce.
Direct inhibition of leaf dark respiration by elevated CO2 is minor in 12 grassland species
Authors: Tjoelker M. G. , Oleksyn J. , Lee T. D. , Reich P. B.
Published: March 2003

•  Direct inhibition of dark respiration by elevated atmospheric concentrations of CO2 could alter the carbon balance of plants and ecosystems. The short‐term response of leaf dark respiration to elevated CO2 concentrations are reported here in 12 grass and forb species of a North American grassland community.

•  Specific respiration rates at 25°C and a range of measurement CO2 concentrations were determined for detached leaves of each species field‐grown in monoculture.

•  On average, respiration rates were 1.8% lower at 700 than at 360 µmol mol−1 CO2. Among species, responses ranged from a 6.4% inhibition to a 2.4% stimulation and were generally not statistically significant. Across a range of CO2 concentrations from 360 to 1300 µmol mol−1, respiration rates declined linearly and were 11% lower at 1300 than 360 µmol mol−1 CO2.

•  Direct inhibition of leaf respiration is small compared with other longer‐term, indirect effects of CO2 on carbon exchange. The direct effects of rising atmospheric CO2 concentrations on respiration rates should result in minimal effects on plant carbon exchange in grasslands.
MAP kinase signal transduction pathways in plants
Authors: Morris Peter C.
Published: March 2003

The mitogen‐activated protein kinase (MAP kinase) signal transduction cascades are routes through which eukaryotic cells deliver extracellular messages to the cytosol and nucleus. These signalling pathways direct cell division, cellular differentiation, metabolism, and both biotic and abiotic stress responses. In plants, MAP kinases and the upstream components of the cascades are represented by multigene families, organized into different pathways which are stimulated and interact in complex ways. Experimental strategies for the analysis of MAP kinase cascades include the yeast two‐hybrid system; using this approach in vitro interactions between specific MAP kinase cascade components have been analysed and putative plant cascades postulated. Transient transformation of protoplasts with epitope‐tagged kinases has allowed cascades to be tested in planta. There is clear evidence for the involvement of MAP kinases in plant cell division and in the regulation of auxin signalling. Biotic (pathogens and pathogen‐derived elicitors from fungi, bacteria and viruses) and abiotic stresses including wounding, mechanical stimulation, cold, drought and ozone can elicit defence responses in plants through MAP kinase pathways. There are data suggesting that ABA signalling utilizes a MAP kinase pathway, and probably ethylene and perhaps cytokinins do so also. The objective of this paper is to review this rapidly advancing field.

Contents

Summary
67

I.
Introduction
68

II.
Background
68

III.
MAP kinase targets and targeting specificity
69

IV.
Assays and inhibitors
70

V.
Two well characterized MAP kinase pathways, Hog1 and Sevenless
71

VI.
MAP kinases in plants
73

VII.
MAP kinases and cell division
76

VIII.
MAP kinases and plant hormones
76

IX.
MAP kinase and abiotic stress
78

X.
MAP kinase and biotic stress
80

XI.
Future perspectives for MAP kinase research in plants
83

Acknowledgements
84

References
84
Light‐dependent growth rate determines changes in the population of Planktothrix rubescens over the annual cycle in Lake Zürich, Switzerland
Authors: Walsby A. E. , Schanz F.
Published: March 2003

• Analyses were made to determine which changes in a Lake Zürich population of Planktothrix rubescens were dependent on light‐ and temperature‐dependent growth rates, and when growth was limited by the mixing depth.

• Changes in vertical distribution of the cyanobacterium, determined weekly from August 1998 to September 1999, were related to growth increments calculated at 1‐h time and 1‐m depth intervals from values of irradiance, attenuance, temperature and biomass in the lake, using algorithms based on growth rates in culture.

• Population biovolume varied annually from 1.2 to 120  cm3 m−2. During summer, modelled growth in the metalimnion matched the 50‐fold population increase. Modelled growth exceeded the observed increase when Planktothrix was mixed into the nutrient‐depleted epilimnion, suggesting nutrient limitation. The measured increase ceased when the mixed depth exceeded the critical depth for growth in autumn (Sverdrup’s principle). Light limitation explained the gradual decrease of the population in winter. The steep decline in spring had other causes.

• Population changes were largely determined by interactions of light and depth distribution; decreases in nutrient loading have had little impact on Planktothrix growth in Lake Zürich.
Variations in ageing and meristematic activity in relation to flower‐bud and fruit excision in the Beta species complex
Authors: Hautekèete N.‐C. , Piquot Y. , Van Dijk H.
Published: March 2003

• Removal of developing fruits delays ageing in many annual plant species. This has long been seen as evidence that ageing is caused by resource depletion due to fruit development. Excision experiments can be interpreted from both evolutionary‐ecology and resource‐allocation viewpoints. Iteroparous (reproducing repeatedly) and annual plants may show different responses to excision. Furthermore, under the resource‐depletion hypothesis, the more precocious the excision of reproductive organs, the greater the effect on allocation patterns.

• A controlled‐conditions experiment was set up involving six life cycles (from long‐lived iteroparous to annual taxa of wild beets, Beta spp.) under three treatments of excision of reproductive‐parts (buds, fruits and control).

• Treatment effect was similar in semelparous and iteroparous beets, although effect on reproduction was more obvious in iteroparous ones. Flower‐bud removal tended to induce resource allocation in new reproductive meristems, whatever the life cycle, without any effect on ageing in semelparous beets and probably none on survival in most iteroparous plants. Fruit removal had no effect.

• These results and the occurrence of between‐accessions variation are discussed in terms of the ecological significance of optimal allocation strategies.
Using radiocarbon to determine the mycorrhizal status of fungi
Authors: Hobbie Erik A. , Weber Nancy S. , Trappe James M. , Van Klinken Gert J.
Published: March 2003

Measurements of 13
C in fungal sporocarps are useful in assessing mycorrhizal or saprotrophic status. Because
14
C measurements can indicate the age of fungal carbon (C) and mycorrhizal fungi depend closely on recent photosynthate,
14 C may provide additional insight into possible mycorrhizal status.

Sporocarps, needles, and litter from Woods Creek, OR, USA together with archived sporocarps were measured for 14 C content by accelerator mass spectrometry.

Known mycorrhizal fungi resembled current‐year needles ( Amanita
,
Cantharellus
and
Gomphidius
) or atmospheric CO
2
(
Tuber
) in
14
C and indicated an average age of 0–2 yr for incorporated C, whereas saprotrophic genera (
Pleurocybella
,
Lepiota
and
Hypholoma
) were composed of C at least 10 yr old. Of genera tentatively considered mycorrhizal from previous work with
13
C, only
Otidia
and
Sowerbyella
appeared mycorrhizal from
14
C measurements, whereas
Aleuria
,
Clavulina
,
Paurocotylis
and
Ramaria (sensu lato ) consisted of older carbon and were presumably saprotrophic.

14
C clearly separated known mycorrhizal or saprotrophic fungi and indicated
13
C measurements should be interpreted cautiously on species of unknown status.
14
C results for needles and mycorrhizal fungi suggested that C sources other than atmospheric CO
2
may contribute small amounts of C. Possible sources include storage of carbohydrates and amino acids, organic nitrogen uptake, and incorporation of soil‐respired CO
2 by anaplerotic or photosynthetic pathways.
The influence of socio‐economic status on salt consumption in Northern Ireland
Authors: Purdy Joanna , Armstrong Gillian , McIlveen Heather
Published: March 2003

The long‐established association between high salt consumption and hypertension has led to calls for a reduction in salt intake. There is particular concern for the health status of Northern Irish consumers, who already have among the highest rates of coronary heart disease and stroke in the United Kingdom. With these concerns in mind, it is essential to establish the sources and patterns of salt consumption from discretionary and processed food sources before a reduction can be achieved. This study investigated differences in salt consumption patterns among consumers of varying socio‐economic status. Research consisted of a consumer questionnaire (n= 360) distributed within Northern Ireland. The results of the study revealed high discretionary salt usage and frequent consumption of processed foods among consumers of lower socio‐economic status. General observations from the questionnaire would suggest a need for improved health education for consumers in this group. The objective of health promotion should be to encourage a reduction in table and cooking salt usage and, in particular, in the consumption of highly salted processed foods. Enhanced product labelling is also encouraged to increase consumer awareness of current salt levels in food and of the availability of low‐salt foods. In addition, the results of this study advocate further development activity in the production of product formulations with low‐salt status.
Healthy eating in the school environment – a holistic approach*
Authors: Burke Linda
Published: March 2003

The curriculum that pupils are taught within the classroom environment can either be reinforced or weakened by what goes on in the rest of the school environment. The study focused on pupils aged 11–12 years, to establish if healthy eating theory was put into practice in the school environment. The research encompassed three areas within the school: the pupils who are the recipients of the theory; the teacher who teaches them the importance of food and cooking skills; and the providers of food within the school environment. Three different post‐primary schools located within the Coleraine area of Northern Ireland were used.
An evaluation of consumer participation in hospital breast services
Authors: Innes L. , Bowen L. , Bruce N. , Scott L. , Williams P.
Published: March 2003

Community expectations and research demonstrate that consumers play an important role in shaping services for women with breast cancer. Consumer contribution has been mandated recently in Victoria, Australia, to ensure the inclusion of consumer involvement in the planning and decision‐making processes within health organizations. As part of the redevelopment of breast services in Victoria, Southern Health has been funded to plan local improvements to care co‐ordination for women diagnosed with breast cancer in the southern metropolitan area of Melbourne. The establishment of effective consumer participation in breast services is an integral aspect of this project and a range of initiatives has been undertaken to achieve meaningful consumer involvement including the appointment of a consumer advisor; appointment of staff with extensive knowledge in women's health and community development to the project; establishment of a consumer reference group; and plans made to improve the receptivity of health service systems to consumer input. A preliminary evaluation of this ongoing project has indicated that a productive role for consumers in service practice review and policy and planning activities has been established and some change and engagement of staff has occurred. There is still work to be done to promote the involvement of a wider range of health professionals and to increase the level of trust between consumers and staff.
Differential Regulation of Somatodendritic Serotonin 5‐HT1AReceptors by 2‐Week Treatments with the Selective Agonists Alnespirone(S‐20499) and8‐Hydroxy‐2‐(Di‐n‐Propylamino)tetralin
Authors: Casanovas J. M. , Vilaró M. T. , Mengod G. , Artigas F.
Published: March 2003

Abstract : Single treatment with the serotonin (5‐hydroxytryptamine)
5‐HT1A receptor agonists
8‐hydroxy‐2‐(di‐n‐propylamino)tetralin (8‐OH‐DPAT) and alnespirone
(S‐20499) reduces the extracellular 5‐HT concentration (5‐HText) in
the rat midbrain and forebrain. Given the therapeutic potential of selective
5‐HT1A agonists in the treatment of affective disorders, we have
examined the changes in 5‐HT1A receptors induced by 2‐week minipump
administration of alnespirone (0.3 and 3 mg/kg/day) and 8‐OH‐DPAT (0.1 and 0.3
mg/kg/day). The treatment with alnespirone did not modify baseline
5‐HText but significantly attenuated the ability of 0.3 mg/kg s.c.
alnespirone to reduce 5‐HText in the dorsal raphe nucleus (DRN) and
frontal cortex. In contrast, the ability of 8‐OH‐DPAT (0.025 and 0.1 mg/kg
s.c.) to reduce 5‐HText in both areas was unchanged by 8‐OH‐DPAT
pretreatment. Autoradiographic analysis revealed a significant reduction of
[3H]8‐OH‐DPAT and [3H]WAY‐100635 {3H‐labeled
N‐[2‐[4‐(2‐methoxyphenyl)‐1‐piperazinyl]ethyl]‐N‐(2‐pyridyl)cyclohexanecarboxamide
· 3HCl} binding to somatodendritic 5‐HT1A receptors (but not
to postsynaptic 5‐HT1A receptors) of rats pretreated with
alnespirone but not with 8‐OH‐DPAT. In situ hybridization analysis revealed no
change of the density of the mRNA encoding the 5‐HT1A receptors in
the DRN after either treatment. These data indicate that continuous treatment
for 2 weeks with alnespirone, but not with 8‐OH‐DPAT, causes a functional
desensitization of somatodendritic 5‐HT1A receptors controlling 5‐HT release in the DRN and frontal cortex.
Differential Phosphorylation of Syntaxin and Synaptosome‐Associated Protein of 25 kDa (SNAP‐25) Isoforms
Authors: Risinger Carl , Bennett Mark K.
Published: March 2003

Abstract : The synaptic plasma membrane proteins syntaxin and
synaptosome‐associated protein of 25 kDa (SNAP‐25) are central participants in
synaptic vesicle trafficking and neurotransmitter release. Together with the
synaptic vesicle protein synaptobrevin/vesicle‐associated membrane protein
(VAMP), they serve as receptors for the general membrane trafficking factors
N‐ethylmaleimide‐sensitive factor (NSF) and soluble NSF attachment
protein (α‐SNAP). Consequently, syntaxin, SNAP‐25, and VAMP (and their
isoforms in other membrane trafficking pathways) have been termed SNAP
receptors (SNAREs). Because protein phosphorylation is a common and important
mechanism for regulating a variety of cellular processes, including synaptic
transmission, we have investigated the ability of syntaxin and SNAP‐25
isoforms to serve as substrates for a variety of serine/threonine protein
kinases. Syntaxins 1A and 4 were phosphorylated by casein kinase II, whereas
syntaxin 3 and SNAP‐25 were phosphorylated by Ca2+ ‐ and
calmodulin‐dependent protein kinase II and cyclic AMP‐dependent protein
kinase, respectively. The biochemical consequences of SNARE protein
phosphorylation included a reduced interaction between SNAP‐25 and
phosphorylated syntaxin 4 and an enhanced interaction between phosphorylated
syntaxin 1A and the synaptic vesicle protein synaptotagmin I, a potential
Ca2+ sensor in triggering synaptic vesicle exocytosis. No other effects on the formation of SNARE complexes (comprised of syntaxin, SNAP‐25, and VAMP) or interactions involving n‐Sec1 or α‐SNAP were observed. These findings suggest that although phosphorylation does not directly regulate the assembly of the synaptic SNARE complex, it may serve to modulate SNARE complex function through other proteins, including synaptotagmin I.
Formation of N‐Pyroglutamyl Peptides from N‐Glu andN‐Gln Precursors in Aplysia Neurons
Authors: Garden Rebecca W. , Moroz Tatiana P. , Gleeson Juliann M. , Floyd Philip D. , Li Lingjun , Rubakhin Stanislav S. , Sweedler Jonathan V.
Published: March 2003

Abstract : Matrix‐assisted laser desorption/ionization with
time‐of‐flight mass spectrometry is used to examine the formation of
N‐pyroglutamate (pGlu) in single, identified neurons from
Aplysia. Six pGlu peptides are identified in the R3‐14 and the R15
neurons that result from in vivo processing of peptides containing either Glu
or Gln at their respective N‐termini. Moreover, we show that Glu‐derived pGlu
is not a sample collection or measurement artifact. The pGlu peptides are
detected in isolated cell bodies, regenerated neurites in culture,
interganglionic connective nerves, cell homogenates, and collected releasates.
We also demonstrate that R3‐14 cells readily convert a synthetic
N‐Glu peptide to its pGlu analogue, indicating the presence of novel enzymatic activity.
Identification and Characterization of the Rat M1 Muscarinic Receptor Promoter
Authors: Klett Christoph P. R. , Bonner Tom I.
Published: March 2003

Abstract : Five subtypes of the muscarinic receptor have been cloned from both the rat and human genomes. Although all five genes have the coding sequences in a single exon, their structures 5′ of the initiation codon are largely uncharacterized, except for the M4 receptor. In the brain, muscarinic receptors mediate motor and memory function by interaction with their ligand acetylcholine. In addition, the M1 muscarinic subtype has been implicated in behavior, stress‐adaptive cardiovascular reflexes, and blood pressure regulation. In the current study the M1 muscarinic receptor noncoding 5′‐flanking region has been identified and characterized, including the promoter and two 5′ noncoding exons located ~13‐14 kb from the coding exon. Similar to the M4 muscarinic receptor gene the M1 promoter is GC‐rich, contains no TATA box, but has two potential CAAT boxes and several putative binding sites for transcription factors such as SP1 and AP‐1‐3. The transcription initiation site was identified by RNase protection and primer extension. Promoter activity was confirmed in transient expression assays, using luciferase reporter constructs. A 0.89‐kb fragment consisting of 480 bp of the promoter, exon 1, and part of intron 1 expressed luciferase activity in two M1 receptor‐expressing cell lines (CCL‐107 and CCL‐147), whereas a longer fragment (1.5 kb) that extends into intron 2 demonstrated significantly increased luciferase activity. The constructs exhibited responses indicating the presence of functional glucocorticoid‐, acute‐phase‐, and heat shock‐responsive elements.
Activation of DNA‐Dependent Protein Kinase May Play a Role in Apoptosis of Human Neuroblastoma Cells
Authors: Chakravarthy Balu R , Walker Teena , Rasquinha Ingrid , Hill Irene E , MacManus John P
Published: March 2003

Abstract : Treating SH‐SY5Y human neuroblastoma cells with 1
μM staurosporine resulted in a three‐ to fourfold higher
DNA‐dependent protein kinase (DNA‐PK) activity compared with untreated cells.
Time course studies revealed a biphasic effect of staurosporine on DNA‐PK
activity : an initial increase that peaked by 4 h and a rapid decline that
reached ~5‐10% that of untreated cells by 24 h of treatment. Staurosporine
induced apoptosis in these cells as determined by the appearance of
internucleosomal DNA fragmentation and punctate nuclear morphology. The
maximal stimulation of DNA‐PK activity preceded significant morphological
changes that occurred between 4 and 8 h (40% of total number of cells) and
increased with time, reaching 70% by 48 h. Staurosporine had no effect on
caspase‐1 activity but stimulated caspase‐3 activity by 10‐15‐fold in a
time‐dependent manner, similar to morphological changes. Similar
time‐dependent changes in DNA‐PK activity, morphology, and DNA fragmentation
occurred when the cells were exposed to either 100 μM ceramide or UV radiation. In all these cases the increase in DNA‐PK activity preceded the appearance of apoptotic markers, whereas the loss in activity was coincident with cell death. A cell‐permeable inhibitor of DNA‐PK, OK‐1035, significantly reduced staurosporine‐induced punctate nuclear morphology and DNA fragmentation. Collectively, these results suggest an intriguing possibility that activation of DNA‐PK may be involved with the induction of apoptotic cell death.
Neurofibrillary Degeneration in Progressive Supranuclear Palsy and Corticobasal Degeneration
Authors: Sergeant N , Wattez A , Delacourte A
Published: March 2003

Abstract : Pathological tau prroteins that constitute the basic matrix of neuronal inclusions observed in numerous neurodegenerative disorders are disease specific. This is mainly the consequence of the aggregation of specific sets of tau isoforms according to the diseases, i.e., six isoforms in Alzheimer's disease (AD) and exclusively the three tau isoforms lacking the corresponding sequence of exon 10 (E10‐) in Pick's disease (PiD). By using antibodies specific to the different tau isoforms and one‐ and two‐dimensional gel electrophoresis followed by western blots, we demonstrate herein a third group of neurodegenerative disorders characterized by intraneuronal inclusions exclusively constituted of tau isoforms containing the sequence corresponding to exon 10, progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Together, tau isoforms with exon 10 clearly differentiate three groups of neurodegenerative diseases : AD, PiD, and PSP/CBD. For each group, the neuropathological nd clinical phenotypes are most likely related to specifric sets of tau isoforms expressed by the vulnerable neuronal populations. The recently described mutations of the tau gene responsible for familial frontotemporal dementias also support this hypothesis.
Isolation of 10 Differentially Expressed cDNAs in Differentiated Neuro2a Cells Induced Through Controlled Expression of the GD3 Synthase Gene
Authors: Liu Hong , Nakagawa Takatoshi , Kanematsu Tae , Uchida Takafumi , Tsuji Shuichi
Published: March 2003

Abstract: Recently, we showed that transfection of GD3 synthase cDNA into Neuro2a cells, a mouse neuroblastoma cell line, causes cell differentiation with neurite sprouting. In a search for the genes involved in this ganglioside‐induced Neuro2a differentiation, we used a tetracycline‐regulated GD3 synthase cDNA expression system combined with differential display PCRs to identify mRNAs that were differentially expressed at four representative time points during the process. We report here the identification of 10 mRNAs that are expressed highly at the Neuro2a differentiated stage. These cDNAs were named GDAP1–GDAP10 for (ganglioside‐induced differentiation‐associated protein) cDNAs. It is interesting that in retinoic acid‐induced neural differentiated mouse embryonic carcinoma P19 cells, GDAP mRNA expression levels were also up‐regulated (except that of GDAP3), ranging from three to > 10 times compared with nondifferentiated P19 cells. All the GDAP genes (except that of GDAP3) were developmentally regulated. The GDAP1, 2, 6, 8, and 10 mRNAs were expressed highly in the adult mouse brain, whereas all the other GDAP mRNAs were expressed in most tissues. Our results suggested that these GDAP genes might be involved in the signal transduction pathway that is triggered through the expression of a single sialyltransferase gene to induce neurite‐like differentiation of Neuro2a cells.
Calcium Influx Through NMDA Receptors, Chronic Receptor Inhibition by Ethanol and 2‐Amino‐5‐Phosphonopentanoic Acid, and Receptor Protein Expression
Authors: Chen Xingyu , Moore‐Nichols David , Nguyen Hoanh , Michaelis Elias K.
Published: March 2003

Abstract: Chronic treatment of neurons with either ethanol or competitive and noncompetitive antagonists of NMDA receptors leads to enhanced expression of NMDA receptor density and function in neurons. The signal transduction pathways for such receptor up‐regulation are not known. The focus of the present study was on the role of Ca2+ entry into neurons, either through receptor or voltage‐gated channels, in the expression of the NMDA receptor subunit NR1 and the 71‐kDa glutamate‐binding protein (GBP) of a glutamate/NMDA receptor‐like complex. Chronic inhibition of NMDA receptors in cortical neurons in primary cultures by either 100 mM ethanol or 100 μM 2‐amino‐5‐phosphonopentanoic acid (2‐AP5) increased the expression of NR1 and GBP. The effect of 2‐AP5 on the expression of the two proteins was not additive with that of ethanol when neuronal cultures were treated with both agents at the same time. However, the effects of ethanol on NR1 and GBP expression were blocked by the simultaneous treatment with NMDA (50 μM). Activation or inhibition of other glutamate ionotropic receptors had no effect on the expression of NR1 and GBP. The inhibition of L‐ or N‐type voltage‐sensitive Ca2+ channels and voltage‐gated Na+ channels also had little effect on the expression of either protein; neither did exposure of neurons to elevated extracellular Ca2+ concentrations (3 or 5 mM). On the other hand, treatment of neurons for 48 h with the intracellular Ca2+ chelator BAPTA‐AM as well as partial chelation of extracellular Ca2+ with EGTA caused an up‐regulation in NR1 and GBP expression. The enhanced expression of NR1 in neurons treated for 48 h with either ethanol or EGTA was correlated with increases in the activity of NMDA receptors demonstrated as a doubling of the NMDA‐stimulated rise in intracellular free Ca2+ concentration. The effects of chronic administration of EGTA on both NR1 expression as well as NMDA receptor function were probably related to an acute inhibition by EGTA of NMDA‐induced Ca2+ influx into neurons. It appears that the expression of both the NR1 subunit of NMDA receptors and the GBP of a receptor‐like complex is regulated by intracellular Ca2+, especially that entering through NMDA receptor ion channels.
Histamine H1 Receptor Binding Capacities in the Amygdalas of the Amygdaloid Kindled Rat
Authors: Toyota H. , Ito C. , Yanai K. , Sato M. , Watanabe T.
Published: March 2003

Abstract: The histamine H1 receptor binding capacity of the amygdalas of amygdaloid kindled rats was studied. In the kindled nonstimulated amygdala, significant decreases in KD and Bmax values compared with those of control amygdala were found 1 week after the last kindled seizure. One month after the last kindled seizure, the decreased KD value was sustained in the kindled nonstimulated amygdala. This decreased Bmax value 1 week after the last kindled seizure in nonstimulated amygdala may partly and transiently contribute to kindled seizure susceptibility. The decreased KD value in nonstimulated amygdala observed until 1 month after the last kindled seizure indicates the long‐lasting increment of binding affinity of the pyrilamine binding site of the histamine H1 receptor in the steady state of kindled seizure susceptibility.
Periodically Fluctuating Protein Kinases Phosphorylate CLOCK, the Putative Target in the Suprachiasmatic Nucleus
Authors: Tamaru Teruya , Okada Masato , Nagai Katsuya , Nakagawa Hachirou , Takamatsu Ken
Published: March 2003

Abstract: We studied nuclear protein phosphorylation in the rat suprachiasmatic nucleus (SCN) and found that a nuclear fraction of the SCN contained histone H1 kinase activity that periodically fluctuated with a diurnal rhythm, reaching a maximum at the midpoint of the light phase and a minimum at the midpoint of the dark phase. A p13suc1‐bound fraction from the SCN nuclear fraction also exhibited diurnally fluctuating histone H1 kinase activity. Using in situ kinase assay, three histone H1 kinases, p45PFK, p100PFK, and p200PFK (termed periodically fluctuating protein kinases, or PFKs) were found in the p13suo1‐bound fractions. p45PFK exhibited the highest level of light/dark cycle phosphorylation activity fluctuation. p45PFK highly phosphorylated the Ser‐Pro‐rich region of CLOCK, the putative physiological target. These results suggest that PFKs, especially p45PFK, are involved in circadian clock‐related signal transduction and gene expression, through the phosphorylation of target proteins such as CLOCK.