bluuebunny/crossref_metadata_2025_split huggingface dataset:
Terpenes and the thermotolerance of photosynthesis
Authors: Singsaas Eric L. 
Published: March 2003

A walk through the forest is a good way to become aquainted with the variety of terpenes emitted by plants. The most fragrant of these are the monoterpenes, which lend a distinctive smell to trees (e.g. α‐ and β‐pinene from pines), mints (e.g. menthol from peppermint), fruits (e.g. limonene from citrus) and flowers (e.g. geraniol from roses). In addition to adding fragrance, phytogenic hydrocarbons play an important role in atmospheric chemistry. This was recognized as early as 1960 by Fritz Went who noted that blue hazes often formed above forested areas (Went, 1960). This idea was picked up by US President Ronald Reagan who accused trees of polluting the atmosphere, although in truth phytogenic hydrocarbons only contribute to pollution in air that is already contaminated by industry or automobile exhaust (Feshenfeld et al., 1992).Terpenes serve a variety of functions in plants including deterring herbivores and attracting pollinators. Until recently, the function of terpene emission from some groups of plants, which do not store the terpenes in their tissues, has been a mystery. Following the discovery that isoprene, a hemiterpene, increases the thermotolerance of photosynthesis in some species (Sharkey & Singsaas, 1995; Singsaas et al., 1997), Loreto et al. (1998) discovered that thermotolerance of the monoterpene‐emitting oak, Quercus ilex, increases when leaves are fumigated with monoterpenes. Now, a report by Delfine et al. in this issue (pp. 27–36) provides further support for the hypothesis that terpenes play a role in thermotolerance of leaves and suggests, intriguingly, that the mechanism by which this occurs is not limited to plants that make these compounds.
Water stress and Sphaeropsissapinea as a latent pathogen of red pine seedlings
Authors: Stanosz G. R. , Blodgett J. T. , Smith D. R. , Kruger E. L. 
Published: March 2003

Summary

•  The role of water stress in the initiation of collar rot by Sphaeropsis sapinea in asymptomatically colonized Pinus resinosa seedlings is reported.

• Mortality and frequency of identification of the pathogen was quantified for seedlings subjected to different water regimes or watering regime–fungicide (benomyl) combinations in glasshouse experiments.

•  In experiment 1, seedling mortality ranged from 8% of repeatedly watered seedlings to 50% of those in the driest regime; data analysis indicated a high probability that mortality was not independent of watering regime. Seedlings developed symptoms resembling those of Sphaeropsis collar rot, and S. sapinea was identified from living (42%) and dead (92%) seedlings. In experiment 2, mortality of repeatedly watered seedlings was low, irrespective of fungicide application. For nonwatered seedlings, however, mortality was greater among seedlings not treated with fungicide (61%) than among benomyl‐treated seedlings (37%); data analysis indicated a high probability that mortality was not independent of fungicide treatment.

• Sphaeropsis sapinea can act as a latent pathogen; physiological alteration, through water stress, can effect release from the quiescent condition to result in rapid disease development.
Free‐air CO2 enrichment (FACE) using pure CO2 injection: system description
Authors: Okada M. , Lieffering M. , Nakamura H. , Yoshimoto M. , Kim H. Y. , Kobayashi K. 
Published: March 2003

Summary

A free air CO2 enrichment (FACE) system in which rice was grown under elevated CO2 conditions by releasing high pressure, pure CO2 from emission tubes surrounding the crop is described here. Unlike other (FACE) systems, blowers were not used to mix the emitted CO2 with the surrounding air.
Four 12‐m diameter emission structures (‘rings’) were constructed. Monitoring and control of CO2 emission was carried out by a series of CO2 and wind sensors, data loggers, controllers and valves. The target CO2 concentration ([CO2]) was 200 µmol mol−1 above ambient; enrichment was carried out continuously.
Temporal [CO2] control was adequate, with c. 60 and 90% of the air samples at ring center having a [CO2] within 10 and 20% of the target, respectively. Spatial [CO2] distribution was also adequate, with 60% of the ring area having a [CO2] that was within 15% of that at the center.
At comparable wind speeds, the pure CO2 injection FACE system described here had a similar performance to that of FACE designs that use blowers to mix the injected CO2 with the air.
The costs of reproduction in plants
Authors: Obeso José Ramón 
Published: March 2003

SummaryThis review reports on the processes associated with costs of reproduction, including some theoretical considerations, definitions and methodological aspects, followed by a list of the situations where costs are difficult to find. Despite some exceptions, case studies, examined by trade‐offs between reproduction and other life‐history traits, generally support the predictions of the cost of reproduction hypothesis. The cost of reproduction as an evolutionary determinant of sexual dimorphism in life history traits in dioecious species was specifically tested, considering that the higher cost of reproduction in females has driven the life history traits related to sexual dimorphism. Females of woody dioecious species were consistently smaller than males supporting the costs of reproduction hypothesis. By contrast, females of herbaceous perennials were generally the larger sex, which did not fit the expectations of the hypothesis. Finally, the mechanisms that enable the compensation of the reproductive costs are detailed, including the plastic responses of photosynthesis and growth, the effects of the timing of investment, plant architecture and plant physiological integration.

Contents

Summary
321

I.
Introduction
321

II.
Theory on costs of reproduction
322

III.
Methodological aspects
324

IV.
Empirical evidence
328

V.
Plant size and costs of reproduction
330

VI.
Costs of reproduction in sexually dimorphic plants
331

VII.
Compensation of the costs
333

VIII.
Concluding comments and future perspectives
336

Acknowledgements
337

References
337
The profile of women entrepreneurs: a sample from Turkey
Authors: Ufuk Hatun , Özgen Özlen 
Published: March 2003

AbstractThis research was carried out among 220 married women in business in Ankara. Its aim was to determine the profile of women entrepreneurs. A random sampling method was used and data were collected through individual interviews (face‐to‐face). The study examined working status, reasons for being in business and the types of businesses involved. It examined the difficulties experienced in starting up and maintaining the businesses, the risks involved, earnings, the characteristics of the entrepreneurs and future planning. Government rules and regulations were considered, as was the willingness of women entrepreneurs to participate in training programmes. The women’s ages, educational levels and the extent of their business experience were also examined.
An analysis of modern fashion designs as influenced by Asian ethnic dress
Authors: Yu Haekyung L. , Kim Chanju , Lee Juhyeon , Hong Nayoung 
Published: March 2003

AbstractThis study analysed modern fashion designs which show influences of Asian ethnic dresses focusing on China, Indonesia, Japan, Korea and Vietnam. A total of 190 designs presented during 1982–97 were collected from seven magazines. There were 68 designs with Chinese influences, 49 for Japan, 35 for Korea, 21 for Indonesia and 5 for Vietnam. Twelve designs showed the influences of more than one country. Each design was content analysed in terms of eleven aspects (shape, garment type, silhouette, colour, feature of fabric, surface pattern, trimming, how to wear, accessories, hair‐style and make‐up). The degree of influence was measured on a 3‐point scale ranging from 1 (symbolic resemblance) to 2 (modification) and 3 (replication). The results confirmed that China and Japan have been the most well‐known sources of Oriental culture in fashion world. Influence of ethnic dresses were most evident in the aspects related to materials (surface pattern, feature of fabric and colour). The Indonesian sarong and the way to wrap skirts around the waist were also frequently adopted in modern fashion.
Determinants of consumers’ aesthetic responses to Point‐of‐Purchase materials
Authors: Jansson C. , Bointon B. , Marlow N. 
Published: March 2003

AbstractThe four‐dimensional nature of the Kaplans’ model of aesthetic response to images was tested on Point‐of‐Purchase (POP) material. It was found that only two robust dimensions emerged in the analysis, Clarity and Mystery. These however, had a significant influence on the subjects’ rating of the POP’s attractiveness. Path analysis suggested each of these dimensions was independent of the other. The implications of the findings are discussed and possible future areas of research identified.
Fatty acid composition of raw caprine milk of a native Greek breed during lactation
Authors: Kondyli Efthymia , Katsiari Maria C 
Published: March 2003

The fatty acid (FA) and free fatty acid (FFA) profiles of caprine milk from a native Greek breed were investigated during a period of 6 months (January–June). The most abundant FAs were palmitic, oleic, stearic and capric. The short‐ and medium‐chain FAs represented 17.5 and 14.5% of total FA, respectively, while long‐chain FAs accounted for the rest (68.0%). From January to April, the major FFAs were acetic, palmitic, stearic and caproic, but afterwards, acetic and propionic were the principal FFAs, followed by stearic, palmitic, oleic and capric.
Tubulin stimulates adenylyl cyclase activity in C6 glioma cells by bypassing the β‐adrenergic receptor: a potential mechanism of G protein activation
Authors: Yan Kun , Popova Juliana S , Moss Amy , Shah Bindu , Rasenick Mark M. 
Published: March 2003

While the cytoskeleton is known to play several roles in the biology of the cell, one role, which has been revealed only recently, is that of a participant in the signal transduction process. Tubulin binds specifically to the α subunits of Gs (stimulatory GTP‐binding regulatory protein of adenylyl cyclase), Gi1 (inhibitory protein of adenylyl cyclase), and Gq and transactivates those molecules through direct transfer of GTP. The relevance of this transactivation process to G proteins which are normally activated by a neurotransmitter‐occupied receptor is the subject of this study. C6 glioma cells, made permeable with saponin, retained tight coupling between Gs and the β‐adrenergic receptor. Although 5‐guanylylimidodiphosphate (GppNHp) was incapable of activating Gs (and subsequently, adenylyl cyclase) in the absence of agonist, tubulin with GppNHp bound (tubulin‐GppNHp) activated adenylyl cyclase with an EC50 of 30 nm. Desensitization of β‐adrenergic receptors by isoproterenol exposure had no effect on the ability of tubulin‐GppNHp to activate Gs and adenylyl cyclase. When the photoaffinity GTP analog, azidoanilido GTP (AAGTP; P3(4‐azidoanilido)‐P1‐5'‐GTP), was added to C6 membranes or permeable C6 cells, it was only weakly incorporated by Gαs in the absence of isoproterenol. When the same concentration of dimeric tubulin with AAGTP bound was introduced, AAGTP was transferred from tubulin to Gαs, activating the latter species. Similar ‘preferential’ activation of Gαs by tubulin‐AAGTP versus the free nucleotide was seen using purified components. Thus, membrane‐associated tubulin may serve to activate Gαs, independent of signals not normally coupled to that protein. Tubulin may act as an agent to link a variety of membrane‐associated signalling systems.
Axonal transport of VR1 capsaicin receptor mRNA in primary afferents and its participation in inflammation‐induced increase in capsaicin sensitivity
Authors: Tohda Chihiro , Sasaki Miwa , Konemura Takashi , Sasamura Takashi , Itoh Masayuki , Kuraishi Yasushi 
Published: March 2003

Capsaicin receptors are expressed in primary sensory neurons and excited by heat and protons. We examined the inflammation‐induced changes of the level of VR1 capsaicin receptor mRNA in sensory neurons and the sensitivity of primary afferents to capsaicin. Carrageenan treatment induced axonal transport of VR1 mRNA, but not that of preprotachykinin mRNA, from the dorsal root ganglia to central and peripheral axon terminals. The sensitivity of central terminals to capsaicin, which was estimated by measuring the capsaicin‐evoked release of glutamate from the dorsal horn, was increased by peripheral inflammation, and such an increase was suppressed by inhibiting the RNA translation in the dorsal horn with cycloheximide and an intrathecal injection of VR1 antisense oligonucleotides. Thus, peripheral inflammation induces the axonal transport of VR1 mRNA, which may be involved in the hypersensitivity of primary afferents to capsaicin and the production of inflammatory hyperalgesia.
Selective small‐molecule inhibitors of glycogen synthase kinase‐3 activity protect primary neurones from death
Authors: Cross Darren A. E. , Culbert Ainsley A. , Chalmers Katy A. , Facci Laura , Skaper Stephen D. , Reith Alastair D. 
Published: March 2003

The phosphatidylinositol 3‐kinase (PI 3‐kinase)/protein kinase B (PKB; also known as Akt) signalling pathway is recognized as playing a central role in the survival of diverse cell types. Glycogen synthase kinase‐3 (GSK‐3) is a ubiquitously expressed serine/threonine protein kinase that is one of several known substrates of PKB. PKB phosphorylates GSK‐3 in response to insulin and growth factors, which inhibits GSK‐3 activity and leads to the modulation of multiple GSK‐3 regulated cellular processes. We show that the novel potent and selective small‐molecule inhibitors of GSK‐3; SB‐415286 and SB‐216763, protect both central and peripheral nervous system neurones in culture from death induced by reduced PI 3‐kinase pathway activity. The inhibition of neuronal death mediated by these compounds correlated with inhibition of GSK‐3 activity and modulation of GSK‐3 substrates tau and β‐catenin. Thus, in addition to the previously assigned roles of GSK‐3, our data provide clear pharmacological and biochemical evidence that selective inhibition of the endogenous pool of GSK‐3 activity in primary neurones is sufficient to prevent death, implicating GSK‐3 as a physiologically relevant principal regulatory target of the PI 3‐kinase/PKB neuronal survival pathway.
Impact of endogenous nitric oxide on microglial cell energy metabolism and labile iron pool
Authors: Chénais Benoît , Morjani Hamid , Drapier Jean‐Claude 
Published: March 2003

AbstractMicroglial activation is common in several neurodegenerative disorders. In the present study, we used the murine BV‐2 microglial cell line stimulated with γ‐interferon and lipopolysaccharide to gain new insights into the effects of endogenously produced NO on mitochondrial respiratory capacity, iron regulatory protein activity, and redox‐active iron level. Using polarographic measurement of respiration of both intact and digitonin‐permeabilized cells, and spectrophotometric determination of individual respiratory chain complex activity, we showed that in addition to the reversible inhibition of cytochrome‐c oxidase, long‐term endogenous NO production reduced complex‐I and complex‐II activities in an irreversible manner. As a consequence, the cellular ATP level was decreased in NO‐producing cells, whereas ATPase activity was unaffected. We show that NO up‐regulates RNA‐binding of iron regulatory protein 1 in microglial cells, and strongly reduces the labile iron pool. Together these results point to a contribution of NO derived from inflammatory microglia to the misregulation of energy‐producing reactions and iron metabolism, often associated with the pathogenesis of neurodegenerative disorders.
Overexpression of the signaling adapter FRS2 reconstitutes the cell cycle deficit of a nerve growth factor non‐responsive TrkA receptor mutant
Authors: Zeng Guoqian , O. Meakin Susan 
Published: March 2003

AbstractWe have characterized the cell cycle deficit of a novel TrkA receptor mutant (TrkAS3) that fails to support nerve growth factor (NGF)‐dependent cell cycle arrest and neurite outgrowth. TrkAS3 receptors fail to support an NGF‐dependent increase in the expression of cyclin D1 and the cell cycle inhibitor, p21Waf1/Cip1, two important regulators of G1/S transition, and do not down‐regulate expression of the G2/M phase marker, cdc2/cdk1, or the S phase marker, proliferating cell nuclear antigen. Moreover, NGF‐activated TrkAS3 receptors do not down‐regulate cyclin‐dependent kinase 4 phosphorylation of the retinoblastoma protein, essential for G1 arrest, in comparison to NGF‐activated wild‐type TrkA. Collectively these data indicate that TrkAS3 receptors fail to support NGF‐dependent G1 arrest. Interestingly, ectopic expression of regulators of G1/S arrest, such as cyclin D1 or inhibitors of cell cycle (p21Waf1/Cip1, p16INK4A), or the fibroblast growth factor (FGF) receptor substrate‐2 (FRS2) in cells expressing TrkAS3 reconstitutes NGF‐dependent neurite outgrowth. Collectively, these data suggest a model in which NGF‐stimulated TrkA‐dependent activation of FRS2 supports neurite outgrowth through a mechanism that likely involves the induction of p21Waf1/Cip1 expression and the arrest of cells at G1/S.
Potentiation of a sodium–calcium exchanger in the nuclear envelope by nuclear GM1 ganglioside
Authors: Xie Xin , Wu Gusheng , Lu Zi‐Hua , Ledeen Robert W. 
Published: March 2003

AbstractCalcium is recognized as an important intracellular messenger with a pivotal role in the regulation of many cytosolic and nuclear processes. Gangliosides of various types, especially GM1, are known to have a role in some aspects of Ca2+regulation, operating through a variety of mechanisms that are gradually coming to light. The present study provides evidence for a sodium–calcium exchanger in the nuclear envelope of NG108‐15 neuroblastoma cells that is potently and specifically activated by GM1. Immunoblot analysis revealed an unusually tight association of GM1 with the exchanger in the nuclear envelope but not with that in the plasma membrane. Exchanger and associated GM1 were located in the inner membrane of the nuclear envelope, suggesting this system could function to transfer Ca2+between nucleoplasm and the envelope lumen. The GM1‐enhanced exchange was blocked by cholera toxin B subunit while C2‐ceramide, a recently discovered inhibitor of the exchanger, blocked all transfer. Exchanger activity was significantly elevated in nuclei isolated from cells that were induced to differentiate by KCl + dibutyryl‐cAMP, a treatment previously shown to promote up‐regulation of nuclear GM1 in conjunction with axonogenesis. Similar enhancement was achieved by addition of exogenous GM1 to nuclei from undifferentiated cells. These results suggest a prominent role for nuclear GM1 in regulation of nuclear Ca2+homeostasis.
Cationic interactions at the human dopamine transporter reveal binding conformations for dopamine distinguishable from those for the cocaine analog 2α‐carbomethoxy‐3α‐(4‐fluorophenyl)tropane
Authors: Chen Nianhang , Sun LingLing , Reith Maarten E. A. 
Published: March 2003

AbstractIn membrane preparations, CFT, a phenyltropane cocaine analog, and dopamine (DA) interact with the recombinant human dopamine transporter (hDAT) in Na+‐free medium. Na+ markedly increased the transporter's affinity for CFT, but had little or no effect on DA potency for inhibiting CFT binding. Raising [Na+] from 20 to 155 mm reduced Li+‐induced increase in DA Ki, but not CFT Kd. The presence of 155 mm Na+ enhanced the tolerance to low pH of CFT Kd but not DA Ki. Leucine substitution for tryptophan 84 (W84L) in transmembrane domain (TM) 1 or asparagine substitution for aspartate 313 (D313N) in TM 6 did not or only modestly enhance the affinity of Na+‐independent CFT binding, and retained the near normal ability of DA, Li+, K+, or H+ to inhibit this binding. However, the mutations significantly enhanced the Na+ stimulation of CFT binding as well as the Na+ antagonism against Li+ and H+ inhibition of CFT binding. In contrast, the mutations neither changed the Na+‐insensitive feature of DA Ki nor enhanced the Na+ protection of DA Ki against Li+'s inhibitory effect, though they caused Na+ protection of DA Ki against H+'s inhibitory action. These results are consistent with the existence of binding conformations for DA that are distinguishable from those for CFT, and with a differential association of cation interactions with DA and CFT binding. The mutations likely alter Na+‐bound state(s) of hDAT, preferentially strengthening the positive allosteric coupling between Na+ and CFT binding, and reducing the impact of Li+ or H+ on the CFT binding.
Association of protein kinase C with GABAA receptors containing α1 and α4 subunits in the cerebral cortex: selective effects of chronic ethanol consumption
Authors: Kumar Sandeep , Sieghart Werner , Morrow A. Leslie 
Published: March 2003

AbstractPrevious studies have suggested that protein kinase C (PKC) isoforms differentially influence the sensitivity of γ‐aminobutyric acidA (GABAA) receptor responses in brain. Both PKCγ and PKCε knock‐out mice exhibit altered ethanol potentiation of GABAA receptor mediated Cl– flux. Furthermore, chronic ethanol consumption alters GABAA receptor function and receptor subunit peptide expression by mechanisms that are not yet understood. The present study explored the possibility that PKC isoforms are directly associated with GABAA receptors, and this association is influenced by chronic ethanol exposure. GABAA receptors containing α1 or α4 subunits were immunoprecipitated from solubilized protein derived from the membrane fraction of rat cerebral cortex using selective antibodies. Immunoprecipitated receptors were screened by western blot analysis for the presence of PKCδ, γ and ε isoforms. We found pronounced labeling of PKCγ but not PKCδ or PKCε in the α1 and α4 subunit immunoprecipitates. Immunoprecipitation with PKCγ, but not with IgG antibody also yielded GABAA receptor α1 and α4 subunits in the immunoprecipitate. The association of PKCγ with α1‐containing receptors was decreased 44 ± 11% after chronic ethanol consumption. In contrast, PKCγ associated with α4‐containing receptors was increased 32 ± 7% after chronic ethanol consumption. These results suggest that PKCγ may be involved in GABAA receptor adaptations following chronic ethanol consumption.
Effects of intrahippocampal CT105, a carboxyl terminal fragment of β‐amyloid precursor protein, alone/with inflammatory cytokines on working memory in rats
Authors: Matsumoto Yuji , Watanabe Shigenori , Suh Yoo‐Hun , Yamamoto Tsuneyuki 
Published: March 2003

AbstractIn this study, we examined the effects of a 105 amino acid carboxyl terminal fragment of β‐amyloid precursor protein (CT105) and inflammatory cytokines on working memory in rats, by using a three‐panel runway set‐up. CT105 at 10 nmol/side significantly impaired working memory when it was administered bilaterally into the hippocampus. Furthermore, to elucidate the interaction of CT105 with inflammatory cytokines, we co‐administered tumor necrosis factor‐alpha (TNF‐α) and interleukin‐1β (IL‐1β) in combination with CT105. Concurrent injections of CT105 (1.0 nmol/side) and TNF‐α (100 ng/side) produced a synergistic deficit of working memory, whereas IL‐1β (100 ng/side) combined with CT105 (1.0 nmol/side) did not affect the working memory performance. These results indicate that the CT105‐induced impairment of working memory is strongly aggravated by an increase in the level of the inflammatory cytokine TNF‐α, which may occur in the brains of patients with Alzheimer's disease.